bluuebunny/crossref_metadata_2025 huggingface dataset:
The Performance of Aged Aqueous Foams for Mitigation of Thermal Radiation
Authors: Magrabi S. A. , Dlugogorski B. Z. , Jameson G. J.
Published: August 2010

This paper investigates the effect of aging on the performance of aqueous foams as absorbers of thermal radiation. It employs a previously developed engineering method to evaluate the performance of fire‐fighting foams exposed to high fluxes of thermal radiation (5‐40 kW/m2). A radiator cone from the ISO 5660 cone calorimeter is utilised to generate a uniform heat flux of thermal radiation on a 50mm thick aqueous foam layer. A comparison of the effect of thermal radiation on freshly‐made and aged foam in terms of the drainage, evaporation and foam‐decay characteristics is carried out. Class B fire‐fighting foams in the expansion range 5‐30 are studied. The experimental data for the aged foam reflect real‐life situations. A performance‐cost index developed previously by the authors, is applied to quantify the overall stability of aged fire‐fighting foams exposed to fluxes of thermal radiation. The index demonstrates the superior performance of fresh foams in comparison to aged foams and shows that the low expansion foam (E=5) displays the worst performance to price ratio.
The Influence of Volatiles on Combustion Rate of Loy Yang Coal Char in a Fluidised Bed Combustor
Authors: Ross D. P. , Laurent P. J. , Schluter G. B. , Zhang D. K.
Published: August 2010

An experimental investigation into the influence of volatiles as simulated by propane on the combustion rate of Loy Yang coal char in a bubbling fluidised bed combustor has been conducted. The weight loss and burn‐out times for a batch of +3.35‐3.175 mm sized coal particles were examined at temperatures of 700°C, 800°C and 900° C. Silica sand (+250–180μm) as the bed material was fluidised either by a 10% v/v oxygen stream or 10% v/v oxygen and 3% v/v propane mixture, both balanced with nitrogen. Samples were retrieved at various time increments by means of a movable gauze basket and quenched in a nitrogen stream. It was observed that burnout times of char particles at 700°C, 800°C and 900°C in a propane/air environment were 13%, 39% and 88% greater respectively, than those at the same temperatures but in the 10% v/v oxygen stream. At the lower combustion temperature of 70O°C, minimal effect of extended char combustion times is concordant with observations of particles spending a small proportion of time at the bed surface, where oxygen concentration is lower due to over‐bed burning of propane. At the higher bed temperatures, the reduction in the char combustion rate in the presence of propane is consistent with the transition from over‐bed to in‐bed combustion of propane. Consequently, there is competition between the propane and char for available oxygen, causing a substantial decrease in the char combustion rate with increasing temperature. The influence of propane on the burnout times observed compare favourably to that reported in literature. The rate of char combustion was found to correlate well to the simple diffusion‐controlled oxidation of a char particle in laminar flow.
Simulation of 3D Radiative Heat Transfer Using a Hybrid Numerical Method
Authors: Huawei X. , Chuguan Z. , Zhaohui L. , Wei R.
Published: August 2010

A hybrid‐combination of the Monte Carlo and zone methods [1] is based on the zone method and uses the Monte Carlo method to calculate direct radiative exchange areas. This approach is developed to analyze three‐dimensional radiative heat transfer with anisotropically scattering media. Special technique of the Monte Carlo method for slop walls is presented. The code is applied to two test cases. In the first test case the program is validated by simulating a rectangular enclosure, in which the computed temperatures and wall heat fluxes are compared with Hottel's zone method. In the second case the code is applied to a 100 MW pulverized coal‐fired utility boiler. The geometry is discretised on a Cartesian grid.
An Experimental Study of Calcination of South Australian Caroline Limestone
Authors: Telfer M. , Zhong Z. , Xu Y. , Li D. , Zhang M. , Zhang D. K.
Published: August 2010

Calcination experiments were conducted on Caroline Limestone from 53μm to 1.0 mm in size, under a range of partial pressures of CO2 and total pressures and temperatures between 700–900°C using both an atmospheric and a pressurised thermogravimetric apparatus. Results revealed that under these conditions the calcination of Caroline Limestone was unaffected by particle size. The behaviour was attributed to particle explosion that allowed less diffusion resistances for the larger particles. It still needs to be determined whether the explosion was a result of thermally induced fractures (TIFs) or low‐temperature decomposition of MgCO3. The calcination of Caroline Limestone conducted under a variety of partial pressures of CO2 was found to be proportional to the equilibrium partial pressure of CO2 minus the partial pressure of CO2 at interface, PCO2e ‐ PCO2i, for the 0.21–0.35 and 0.5–0.6mm particle size fractions. For the larger particle size fractions between 0.85–1.0mm and 0.5–0.6mm in N2 environment under higher pressures (up to 5 atm), the use of a constant mole fraction y1, was necessary to correlate the calcination rates with effect of CO2 partial pressure. The calcination rate under these conditions was therefore found proportional to PCO2e ‐ PCO2i ‐ Py1. Calcination rates calculated from data up to 100% conversion for the 0.2–0.35mm particles also required the inclusion of y1 and its value was also found to increase from 0.03 at 850°C to 0.22 at 900°C. The observed trends in the value and requirement of the constant mole fraction, y1 clearly indicates that it is included to account for heat and mass transport processes which supports previous justification for its introduction in the rate equation.
A Study of the Mechanism of Petroleum Coke Pyrolysis
Authors: Shen Bo‐Xiong , Liu De‐Chang , Chen Han‐Ping
Published: August 2010

In this paper, the pyrolysis model given by (1‐α)3.0 is found to predict the pyrolysis of petroleum coke by thermogravimetric analysis. On this basis, the pyrolysis mechanism of petroleum coke is proposed and the kinetic parameters of four types of petroleum cokes are presented.
Robust Stability Conditions for SISO Dynamic Matrix Control
Authors: Dai L.K. , Cheng Z.Q.
Published: August 2010

This paper presents the robust stability conditions for single‐input/single‐output (SISO) dynamic matrix control (DMC). Model uncertainty is described by using a range of possible plant impulse responses, and a new form of DMC algorithm based on a finite impulse response (FIR) model is discussed. Then robust stability conditions for the new DMC algorithm are derived by applying Jury's dominant coefficient lemma. These results provide theoretical foundations for analyzing and designing predictive control systems.
Application of Wavelet Transform to Process Operating Region Recognition
Authors: Zhao Zhong , Jin Yihui
Published: August 2010

Based on the analysis of wavelet transform, we studied how to extract the frequency band and multi‐scale qualitative features of process measurement signals. It was proved that the extracted features could describe the process performance region in a stable and complete way. Combining the pattern inductive algorithm, a method of process region recognition based on wavelet transform has been proposed. Results of an actual application have verified its feasibility and effectivenes.
Operational Optimization of Ideal Internal Thermally Coupled Distillation Columns
Authors: Liu Xing‐Gao , Qian Ji‐Xin
Published: August 2010

Lack of the optimal operation parameters in operation is one of major difficulties associated with the use of advanced energy saving distillation methods. In this paper, the operational optimization of the ideal Internal Thermally Coupled Distillation Column (ITCDIC) is considered. An optimization model and the related simulation algorithm are proposed. An optimization and the related result analysis are carried out, which pave the way for further design studies and its practical application.
A Novel Modeling and Optimal Control Method for Discrete‐Event Chemical Processes
Authors: Dai Huaping , Sun Youxian
Published: August 2010

Discrete‐event chemical processes can be almost characterized as Discrete Event Dynamic Systems (DEDS). In this paper, we present a timed‐event‐multigraph (TEMG) and dioid based modeling method to describe synchronization, sharing and event quantity. On this algebraic basis, the optimal behaviors are found as extreme solutions of a system of inequations over a complete lattice.
Robust Sampled‐Data Control for Fuzzy Uncertain Systems
Authors: Hu L.‐S. , Shao H.‐H. , Sun Y.‐X.
Published: August 2010

Sampled‐data control which is capable of stabilizing general nonlinear systems with the intersample behavior taken into account are of great current interest. In this paper, the Takagi‐Sugeno fuzzy models were considered for representing the nonlinear plants. For the Takagi‐Sugeno fuzzy model and the Takagi‐Sugeno uncertain fuzzy model, the fuzzy sampled‐data control and the robust sampled‐data control were considered in this paper. The robust sampled‐data control for the Takagi‐Sugeno uncertain fuzzy model with the constraints on the states was also developed. The results were described as the matrix inequalities, which could be solved by LMITool. Finally, a numerical example based on the missile autopilot model was considered, the result showed the effectiveness of the proposed procedures.
Principles for Utilization of Seawater in the Flue‐Gas Desulfurization Process
Authors: Yao Tong
Published: August 2010

The Flake‐Hydro Process (SWFGD) is a flue gas desulfurization method in which sea water is used for absorption of sulfur dioxide. Shenzhen West Power Plant Unit 4 (300MW) imported this technology from Norway and installed SWFGD system. At present, the operational situation is good. All performance guarantees are secured. Shenzhen Energy Environmental Engineering Co. Ltd, also takes responsibility for monitoring and study of key techniques.
Classification of Micro‐Particles in Fly Ash
Authors: Sun Jun‐Min , Yao Qiang , Xu Xu‐Chang
Published: August 2010

Fly ash samples collected from five power plants, different in either the rank of the fed coals or the type of the boilers, were analyzed with optical microscopy and scanning electron microscopy. Based on the difference in chemical composition and microstructure, a classification scheme for micro‐particles in fly ash is proposed. First, according to chemical composition, the micro‐particles in fly ash are divided into four groups, namely aluminosilicate, ferruginous, calcareous, and unburnt carbon. Second, these groups are sub‐divided into 16 categories by the difference in morphology and internal microstructure. For example, the aluminosilicate group is sub‐divided into cenospheres, plerospheres, porous spheres, solid spheres, irregular porous particles and dense particles. The microscopic properties of each category are discussed from the environmental and utilization standpoint.
Numerical Simulation of Nagging Films in the Aachen Pressurized Coal Combustion Facility
Authors: Hecken M. , Reichelt L. , Renz U.
Published: August 2010

Combined gas and steam turbine processes based on direct coal firing show a high thermal efficiency. At RWTH Aachen, University of Technology, an experimental test furnace has been built to investigate the pressurized pulverized coal combustion (PPCC). The PPCC‐facility has been constructed as a slag tap furnace. Particles hitting the walls at temperatures above the melting point came stagging depositions and create a film flowing down the reactor walls. As a part of the PPCC‐program different mathematical models have been developed and implemented into the CFD‐code FLUENT to predict the behavior of slag films at the furnace walls. Numerical strategies and the mathematical models used are described in detail.
Effects of Steam Reactivation on the Pore Characteristics of Calcium‐based Absorbent
Authors: Wang Ai‐Jun , Qi Hai‐Ying , You Chang‐Fu , Lu Ping , Xu Xu‐Chang
Published: August 2010

This paper studied the effect of steam reactivation on the pore characteristics of calcium‐based (Ca‐based) absorbent at temperatures of 150‐600d̀C. With a mercury porosimeter, the influence of steam reactivation on the micro‐pores was studied. The effects of steam reactivation on the external morphology were evidenced by Scanning Electron Microscopy (SEM) photographs. At the same time, the fractal dimension was calculated. It is found that the conversion enhancement of Ca‐based absorbent was attributed to the improved pore characteristics of absorbent and the reduced diffusion resistance of SO2 into the pores.
Flow Regimes, Holdup and Pressure Loss for Two‐Phase Flow Through Vertical and Near Vertical Tubes
Authors: Spedding P. L. , Woods G. S. , Rahunathan R. S. , Watterson J. K.
Published: August 2010

Two‐phase, air‐water, co‐current flow in a pipe, slightly inclined from the vertical at +86.5d̀, showed significant differences to both the corresponding vertical data and results obtained for other angles of inclination. The regime map obtained for the inclined flow was the same as that found with the vertical geometry at the higher gas rates where the annular flow regimes were present. The maps for the two geometries exhibited significant differences as the gas rate was lowered and the churn and intermittent flow patterns appeared. Two new flow regimes were discovered in the inclined flow data under these conditions, namely the slug‐blow through slug and the slug‐churn patterns.

The liquid holdup was, in general, greater with the inclined geometry, particularly at lower gas and liquid rates where the new types of flow patterns were in evidence. Models are presented which allow prediction of holdup with the inclined geometty for all patterns except the churn flow regime. The total pressure loss was, in general, higher for the inclined geometry. An explanation is presented based on the anisotropy of the liquid across the pipe due to the inclination from the vertical.
A Study on Increasing Separation Efficiency of an Industrial, Compound Distillation Column
Authors: Mu Shengjing , Su Hongye , Hu Yongyou , Chu Jian
Published: August 2010

Simulation of a multistage distillation column is often required for its design and operation A debottieneck study for an acetic acid (HAc) dehydration column is presented in this paper. The column is consists of 4 structured packing sections at the top, a sieve tray section with smaller diameter in the middle, and a sieve tray section with larger diameter at the bottom By using steady‐state simulation, the bottleneck to increasing the efficiency of separation is identified to be the middle sieve tray section with smaller diameter and smaller tray spacing Renovation schemes without any additional investment on equipment are proposed
Development of a Resin Transfer Molding Test‐bed with Process Control Capability
Authors: Raghavan Kaushik , Palanki Srinivas
Published: August 2010

Fiber reinforced plastic parts have traditionally been manufactured by resin transfer molding. This method is based on a fixed recipe and no attempt is made to control process conditions during the manufacturing process. In this paper, an experimental test‐bed is developed which has the capability of implementing a wide variety of temperature and pressure profiles for the manufacture of plastic parts via resin tranfer molding. The performance of the test‐bed is evaluated by implementing several desired pressure and temperature profiles in production of fiber reinforced polyester parts.
Use of Simulation and Expert Systems to Increase the Energy Efficiency in Cane Sugar Factories
Authors: León Osvaldo Gozá , Victoria Héctor Pérez De Alejo , Rijckaert Marcel
Published: August 2010

As part of a strategy to increase the energy efficiency of Cuban sugar factories, an automated method of analysis has been developed and is being applied based on the use of STA and ANSTE programs STA is a steady state sequential modular simulation program aimed at evaluating energy systems in cane sugar factories ANSTE which is an expert system based on calculations with STA and certain additional information, makes it easy to detect problems affecting the energy efficiency of the factory, and to make recommendations for solutions In this paper, the strategy of these two programs is briefly discussed, and the main features of the STA and ANSTE programs are presented Some problems detected by the expert system and the conceptions of its knowledge base are described An application in an actual factory is presented In this factory, both programs were applied in the evaluation of the energy system, and proposed solutions were accepted by managers
Process Systems Engineering: Successful Application in an Industrial Process
Authors: Tian Yu‐Chu , Tadé Moses O.
Published: August 2010

Process systems engineering (PSE) is an interdisciplinary field covering almost all aspects of processes It deals with complex system problems with considerations of global objectives and performance Through discussion of a successful PSE application in a large‐scale galvanising process, this work showed how the PSE techniques can be applied to real complex processes System analysis was carried out to clarify objectives, define problems, and find some candidate schemes Hierarchical structure was introduced into the system and flows of materials, energy, and information of the system were identified In addition to flows of materials and energy, the information flow played an important role in large‐scale systems and was considered as the third basic flow Computer communications were discussed in both hardware and software Instrumental automation (IA) and supervisory control (SC) were highlighted, in which advanced strategies were implemented for process control, optimisation, and coordination The developed system was successfully put into routine operation
Holdup and Pressure Drop in Vertical and Near‐Vertical Three‐Phase Up‐Flow: A Collection of Flow Regimes
Authors: Spedding P.L. , Woods G.S. , Cooper R.K. , Watterson J.K.
Published: August 2010

Three‐phase oil, water and air data are reported for vertical and near vertical +86 5° upflow in a 0 026 m i d pipe In general, the liquid holdup for near vertical flow was greater than for the corresponding vertical upflow, the exception being at low liquid and superficial velocities under 0 6 m/s and high superficial gas velocities over 20 m/s Here the liquid holdup varied being sometimes below and other times above the corresponding vertical value These variations of liquid holdup were shown to depend on the fine structure of the flow patterns present

The total pressure drop and its component parts showed significantly different patterns of behaviour depending on whether the superficial gas velocity was above or below the rise velocity of a Taylor bubble The total pressure drop generally was greater for near vertical flow compared to the vertical upflow case but reflected changes in the fine structure of the flow patterns A comprehensive collection of flow regimes is included in this paper
Superheated Steam Drying of Paper Web
Authors: Kiiskinen H.T. , Edelmann K.E.
Published: August 2010

The use of superheated steam as a drying medium for paper drying has been studied on a laboratory scale since the mid‐1980s. This paper reviews previous studies in the context of a study aiming at industrial application of superheated steam drying of paper. The drying rates in a superheated steam atmosphere as well as the quality effects of steam drying on paper are both extensively reported in the literature. However, there are a number of questions to be answered before applying steam drying on an industrial scale. Air tightness, quality of steam, and the use of steam are examples of topics to be addressed. To study these questions more closely, a continuous steam dryer was built. Integration of a steam dryer was studied with steady‐state process simulation.
The Differences in Drying Rate Curves of Sintered Glass Beads at Subatmospheric and Atmospheric Pressures and at Lower Pressures in Steam
Authors: Shibata Hiromichi , Ide Mitsuharu
Published: August 2010

Steam drying of sintered glass beads under vacuum was investigated. The drying rates were predicted from an evaporation zone model for the constant rate period, and from a receding evaporation front model for the falling rate period in which the data of moisture contents in the pendular state were estimated from those in air under vacuum. The predicted, as well as observed, normalized drying rate curves including the critical moisture contents in steam under vacuum were different from those in steam at subatmospheric and atmospheric pressures. However, they were similar to those in air under vacuum in the corresponding pressure range. This was because the moisture content in the pendular state under vacuum was larger than that at subatmospheric and atmospheric pressures, and heat transfer was a rate‐controlling step both in steam and in air under vacuum.
Experimental Study of Nanometer TiO2 for Use as an Adsorbent for SO2 Removal
Authors: Luo Yonggang , Li Daji
Published: August 2010

The flue gas desulphurization (FGD) process for the majority of industrial applications worldwide is chemical absorption. A large amount of adsorbent is spent and becomes waste material. If a new type of adsorbent can be found, which utilizes physical adsorption (and hence can be regenerated) instead of chemical absorption, then FGD processes will be greatly improved. Significant technical progress and economic benefits would be obtained.

A new kind of adsorbent, namely nanometer sized TiO2 particles, which is processed and sintered at low temperature and having high porosity and surface area is investigated in this paper. Using different sintering temperatures, four TiO2 adsorbents are prepared. The pore structure of TiO2 particles is characterized by a scanning electron microscope (SEM), the BET method, and calculated pore size distribution by the BJH model. The crystal types of all four samples are found to possess anatase structures by XRD. The tests of adsorption dynamics for FGD and the performance of SO2 removal are investigated in a fixed‐bed system for different samples. Different operating conditions such as adsorption temperature, SO2 concentration in flue gas, and the superficial velocity of flue gas were investigated.

The experimental adsorption breakthrough curves for these types of adsorbents in a fixed‐bed show good SO2 removal performance which is strongly influenced by adsorption temperature, SO2 concentration in the flue gas, and superficial velocity of the flue gas. The mechanism for SO2 removal is demonstrated by infrared (IR) spectroscopy to be mainly physical adsorption. The pore texture of TiO2 particles to be used as a physical adsorbent is very important for its adsorption capacity. The SO2 removal process using TiO2 as a physical adsorbent is reversible, and the TiO2 adsorbent can then be regenerated by raising the temperature.
Ted White's Legacy to Gibbsite Precipitation Research
Authors: Ilievski D.
Published: August 2010

Professor E.T. (Ted) White's direct contribution to the understanding of gibbsite precipitation and to the modelling of this process has been enormous. In addition, he has had, and will continue to have, a profound indirect influence on developments in this area through former students, their students, and others following upon work that he has pioneered. The outcomes have been both academically and commercially important. The precipitation of gibbsite (aluminium trihydroxide) is a critical step in the production of alumina from bauxite, and Australia produces over 25% of the world's smelter grade alumina, earning about $3.5bn in revenue. This paper traces some of the recent developments in this area that have built upon the foundations laid by the seminal studies of Ted and his students.
Free‐falling Crystals: Biological Macromolecular Crystal Growth Studies in Low Earth Orbit
Authors: Judge Russell A. , Snell Edward H. , Pusey Marc L.
Published: August 2010

Spacecraft orbiting the earth experience a reduced acceleration environment due to being in a state of continuous free‐fall. This state colloquially termed microgravity, has produced improved X‐ray diffraction quality crystals of biological macromolecules. Improvements in X‐ray diffraction resolution (or detail) or signal to noise, provide greater detail in the three‐dimensional molecular structure providing information about the molecule, how it works, how to improve its function or how to impede it. Greater molecular detail obtained by crystallization in microgravity, has important implications for structural biology. In this paper we examine the theories behind macromolecule crystal quality improvement in microgravity using results obtained from studies with the model protein, chicken egg white lysozyme.
Improving Renaturation of Proteins from Inclusion Bodies
Authors: Kotlarski Nicholas , O'Neill Brian K. , Dunlop Eric H. , Francis Geoffrey L.
Published: August 2010

The effect of varying mixing rate and mode of dilution during refolding of proteins is poorly characterized. However, these two physical parameters are important design considerations for large‐scale processes. In this paper, an investigation of the refolding of an analogue of Insulin‐like Growth Factor I (LongR3IGF‐I; Wells et al., 1994) is presented. Partially purified inclusion bodies of the protein were isolated from Escherichia coli (E. coli), dissolved following a standardized protocol and refolded in either batch mode under different mixing rates or fed‐batch mode at a protein concentration of up to 2 g L−1. Rate constants for a widely accepted kinetic model of refolding were regressed to transient protein concentration as a key measure of performance. It was found that mixing rate did not significantly alter a first‐order rate constant of correct refolding, kN = 0.17 ± 0.05 min−1. However, it did increase an apparent second‐order rate constant of aggregation, KA, from approximately 1.6 (without stirring) to 3.3 L g−1 (rapidly stirred). Refolding at high protein concentration in fed‐batch mode gave approximately 5‐fold greater maximal yield of renatured protein than in batch mode. This increase in yield of active monomer was accompanied by a reduction in the amount of aggregate species resolved by non‐reducing SDS‐PAGE. Results indicate that gradual addition of denatured protein to give conditions that promote refolding is superior to rapid batch dilution, but an increased rate of mixing reduces the yield of active product by increasing the rate of aggregation. The kinetic model was shown to give a poor description of refolding at high protein concentration in both batch and fed‐batch modes.
Modelling Gaseous NOx Reactions
Authors: Walker G. M. , Larkin F. D. , Holland C. R. , Ahmad M. N.
Published: August 2010

A mathematical model has been developed which accurately simulates a dual pressure nitric acid plant. The model simulates three complex reactions which occur in the plant, namely the oxidation of nitrogen monoxide; the dimerisation of nitrogen dioxide; and the absorption of nitrogen oxides in water.
Consideration of Spent Mushroom Compost as a Source of Energy
Authors: Mccahey S. , Mcmullan J. T. , Williams B. C.
Published: August 2010

The success of the Irish mushroom industry has led to its rapid expansion, particularly in the border counties. Mushrooms grow in a compost of poultry litter, straw and gypsum. After the mushrooms are gathered the spent mushroom compost (SMC) has traditionally been land spread as fertiliser. However, as more intensive practices are adopted, there is insufficient land available for the waste. The difficulties presented in disposing of SMC with environmental sensitivity are now a limiting factor on further growth of the industry.

This paper investigates the potential of SMC combustion with energy recovery. The availability and composition of SMC has been considered with regard to its potential as an energy feedstock. Analyses showed that, on a dry ash free basis, SMC has a calorific value equivalent to sewage sludge. Compositional analysis confirmed the dry fuel as consistent in make‐up and showed the moisture content to remain within 60 to 77 percent, on an as received basis. SMC was found during combustion trials to be a suitable feedstock for combustion in a bubbling fluidised bed unit. Sensitivity studies determined a gate fee of £6.8/tonne for such a process which will compare favourably with landfill prices as they rise form the current £5/tonne.
The Processing and Performance of High Temperature Polymers for Automotive Fluid Handling Applications
Authors: Mccourt M.P. , Mcnally G.M. , Murphy W.R. , Mcnally T.
Published: August 2010

One of the main focuses on automotive engine design in the last number of years has been a move towards engine compactness in an effort to increase cabin space. This has lead to a dramatic increase in temperature around the engine compartment from around 120d̀C to 200d̀C. This exceeds the maximum service temperature of many of the polymer materials currently used in fluid delivery systems. Already some of these components are now of necessity being replaced with metals. These metallic systems although heat resistant, are heavier, difficult to form and prone to fatigue failure. This present work investigates the melt degradation properties at elevated temperatures and the effect of immersion in standard automotive fluids (an extension of SAE J2027) on the mechanical performance of a range of polymers that are potential candidate materials for use in such “under bonnet” high temperature applications. The materials that were investigated included nylons, polypropyleneoxide/polyamide blends (PPO/PA), and polyetherimide (PEI). The rheological characteristics of nylon 4.6, PPO/PA and PEI were investigated and the results showed significant decrease in shear viscosity at dwell times in excess of three minutes for nylon 4.6, and PPO/PA. Injection moulded samples of the nylon 4.6, impact modified nylon 4.6, nylon 12, PPO/PA and PEI were immersed in the standard automotive test fluids, Fuel C, zinc chloride solution and aggressive water. Subsequent mechanical analysis of the various specimens showed only slight decrease in the tensile modulus of the nylon 4.6 after immersion in Fuel C, however significant weight gain and deterioration in tensile modulus were recorded after immersion in aggressive water. Dynamic Mechanical Thermal Analysis on the nylon 4.6 showed only slight decrease in storage modulus (Log E') and Tg, after immersion in Fuel C. However a significant decrease in Tg, by up to 80d̀C was recorded for samples immersed in aggressive water.
A Theory of Liquid Holdup in Stratified Roll Wave Horizontal Flow
Authors: Watterson J.K. , Cooper R.K. , Spedding P.L.
Published: August 2010

A theory of liquid holdup is developed using turbulent eddy theory for stratified roll wave flow in horizontal pipe. Data are predicted within a total error spread of ±10%.
Prediction of Pressure Loss and Holdup in Two Phase Horizontal Co‐current Pipe Flow
Authors: Spedding P.L. , Cooper R.K. , Mcbride W.J.
Published: August 2010

A new method is presented for calculation of two‐phase parameters for horizontal stratified plus roll wave pipe flow. An iterative momentum balance calculation was performed based on the actual average phase velocities and the gas liquid interfacial shape. The liquid holdup and two phase pressure loss was predicted within ±2% of measured values for data obtained over a wide range of pipe diameters.
The Manufacture and Performance of Polyethylene‐Polyisobutylene Films for Cling Applications
Authors: Small C. M. , Mcnally G. M. , Murphy W. R. , Marks A.
Published: August 2010

A range of Linear Low Density Polyethylene (LLDPE) films with polyisobutylene (PIB) content from 2%‐8% was manufactured using a Killion blown film extrusion system and a cast film extrusion system. The films were aged at 25°, 35° and 45° for up 28 days, to enable tack (cling) development. The tack, in both blown and cast films, improved significantly with ageing, at increased storage temperatures and at higher film blow up ratios. FTIR/ATR analysis was used to investigate the surface migration of PIB in the cast films. The results confirmed those determined by mechanical tack (cling) analysis. DSC analysis showed only a slight decrease in film crystallinity with increasing PIB concentration. The film tensile modulus, elongation and tear properties in both MD and TD were not significantly affected by increase in PIB concentration.

A second series of films with 8% PIB content was manufactured from a range of LLDPE'S. FTIR/ATR, DSC and mechanical tack analysis were used to investigate the relationship between polymer properties and migration rates. The study established that crystallinity was the most influential factor governing PIB migration and this could be related to polymer density. Co‐monomer type was found not to be a factor influencing migration of PIB.
The Flow in Cylindrical Cyclones
Authors: Zhao J.Q. , Abrahamson J.
Published: August 2010

A mathematical model for the flow in a cylindrical cyclone is developed, which is an exact solution of the equation of motion for steady axisymmetric inviscid flow with or without a central ‘air’ core, and with a specified distribution of vorticity on the streamlines at inlet boundary.

The theoretical results are compared with experimental data from Smith 1962, showing reasonable agreement for axial velocity profiles and streamline patterns but differences for angular momentum. The effect on the flow pattern of vorticity advected into the inlet stream is discussed.

The model corroborates Smith's 1962 observation that the flow in the lower part of the cyclone has unique characteristics. If the inlet pattern does not match these characteristics, then the flow makes a rapid adjustment in the upper part of the cyclone. The model also shows the commonly observed independence of tangential velocity with axial distance, but only at high swirl.
The Effect of Protein and Broth Impurities on the Partition of Citric Acid into n‐Butyanol from Aqueous Solutions
Authors: Carolan N. , Weatherley L.R.
Published: August 2010

The use of liquid‐liquid extraction for the recovery of biological products from fermentation media by direct extraction may be significantly influenced by the presence of impurities. This can offset the process advantages of using direct whole broth extraction which, if feasible, can reduce the number of stages needed for the required separation. The impurities may slow down mass transfer rate and may also affect the thermodynamic distribution of the required solute into the extracting solvent. In some cases the addition of reagents can be beneficial to the extraction. Here an experimental study is described in which the partitioning of citric acid into n‐butanol in the presence of a range of impurities has been measured. A range of impurities and additives were studied in an attempt to quantify and prioritise those compounds which affect the partition in practice. These comprised a range of proteins, electrolytes, a surfactant and other organic acids. The additives considered included: trypsin, bovine serum albumin, sodium lauryl sulphate, glucose, sucrose, lactic acid, magnesium sulphate and, sodium chloride. The modification of citric acid partitioning into n‐butanol from whole broth, filtered broth and suspensions of reconstituted biomass were also compared. The presence of the proteins and sodium had a detrimental effect on partition. The effect of magnesium sulphate was highly concentration dependent.
The Prediction of Viscosity for Mixtures Using a Modified Square Well Intermolecular Potential Model
Authors: Williams J. D. , Svrcek W. Y. , Monnery W. D.
Published: August 2010

In the chemical and process industries, the viscosity of pure components and mixtures is a required fluid property in the areas of hydraulics, heat transfer, and mass transfer. Hence, there is a definite need for a reliable and accurate method for viscosity calculations of mixtures that is applicable over the entire density range for a wide variety of components.

The Modified Square Well Intermolecular Potential viscosity model developed by Monnery et al. (1998) to predict pure component viscosities offers a good compromise between theory and applicability. In this work, the square well model is extended to mixtures. A total of 276 binary mixtures, including non‐polar and polar components, were used to regress binary interaction parameters for the mixing rules. The predicted mixture viscosities had a 10% average absolute deviation for the entire density range that included the gas, liquid, and dense phases.
Studies on the Dispersion of Carbon Nanotubes in Polycarbonate
Authors: Takase Hirofumi , Odusanya O. S. , Matsuda S. , Murakami A.
Published: August 2010

We investigated the dispersion of carbon nanotubes in a polycarbonate matrix under varying flow conditions to determine the most efficient dispersion parameter. Distributive mixing was investigated by a flow digitization technique as well as electrical conductivity of the materials. Residence time distribution (RTD) was obtained from an integral of the area under an absorbance‐time curve. Total shear strain rate was obtained by multiplying RTD by shear rate. The area ratio of the filler (Ar) was determined by an image analysis technique where fillers less than 0.36μm were counted as unoccupied area. Area ratio decreased with increasing total shear strain rate, while volume resistivity decreased with decreasing area ratio. We observed an optimum value of Ar for conductivity. Increasing barrel temperature did not have a dramatic effect on dispersion. It was observed that the dominant dispersion parameters were shear rate and RTD.
Speciation of Most Volatile Toxic Trace Elements during Coal Combustion
Authors: Yinghui Liu , Chuguang Zheng , Quanhai Wang
Published: August 2010

Different trace elements have different physical and chemical properties. Understanding the speciation of trace elements in coal combustion flue gas is very helpful in order to evaluate their partitioning behaviour, emission control, atmospheric transport, and their effects on the environment and human health. This work used a chemical‐thermal dynamic equilibrium analytical method to study the speciation of the most volatile toxic trace elements in coal, namely mercury, arsenic and selenium, during coal combustion. In our work we established two types of thermal models. The first model is a simple one in which we only consider one type of trace elements and do not consider the interaction between trace elements. The order model is a complex model in which we consider the interaction between trace elements, and the interaction between trace elements and major mineral matter in coal. From the results predicted by these two models in the temperature range between 400 K and 2000 K, and in oxidizing and reducing atmosphere, we concluded that the volatility of three elements is successively in the order: mercury > selenium > arsenic. Chlorine can greatly enhance the evaporation ability of mercury but very little influence on the evaporation of selenium and arsenic. The interaction between trace elements, and between trace elements and other elements in coal, will greatly affect the predicted results.
Particle Assembling on a Plate using Mechano‐Chemical Reaction
Authors: Suzuki Michitaka , Zhi Zhang Da , Iimura Kenji , Hirota Mitsuaki
Published: August 2010

Particle assembling on a basal plate such as a silicon wafer or metal plate is an important technique for electronics, micro‐devices and the sensor industry. A new method of particle assembling using mechano‐chemical reaction is proposed. In this method, a plate surface is treated to hydrophilic condition as the first step, then a diamond needle scratches the plate (fixed on a computer controller X‐Y stage) in higher alcohol solution as the second step. During this time, the scratched surface is changed from a hydrophilic condition to hydrophobic by mechano‐chemical reaction. In the third step, particles with a hydrophobic surface are sprinlked on the plate, then it is washed with clean water. In this procedure, the hydrophobic particles are removed from the hydrophilic surface and only remain on the hydrophobic scratched surface by hydrophobic attraction.

Using this new particle assembling method, we can arrange spherical silica particles in a linear scratch on silicon wafers or metal plates. The remarkable feature of this method is that expensive equipment such as electron or ion beam lithography is not necessary, and particle assemblies can be performed on a conductivity plate such as metal plate.
A Study on Hydrogen Generation Using PEM Cell and Solar Battery
Authors: Kawashima Yousuke , Honda Itsurou , Hosokawa Tsutomu
Published: August 2010

Experiments for hydrogen generation by water electrolysis using solar batteries and a solid polymer electrolyte membrane (PEM) cell were performed. Poly‐crystalline silicon solar batteries and a PEM electrolytic cell of a single sheet were used in this experiment. The output of solar batteries is connected to the electrolytic cell through a DC‐DC converter. The conversion efficiencies of solar energy to hydrogen energy are evaluated. On the basis of experimental results, simple simulations of solar hydrogen generation were performed taking the matching between solar batteries and PEM cells.
Syntheses and Cation‐Binding Abilities of Thiacalix[4]arene Derivtives
Authors: Ouchi Mikio , Mizuno Tetsuji , Maeda Tomoaki , Ebashi Nobuhide , Kitamura Chitoshi , Yoneda Akio , Mocerino Mauro
Published: August 2010

Syntheses and cation‐binding abilities of thiacalix[4]arene derivatives have been investigated. The cation‐binding ability was evaluated by solvent extraction of metal picrates (some alkali, alkaline earth, and heavy metals) between water and dichloromethane. Although the compounds have lower extractability for metals compared with those of the corresponding calix[4]arene derivatives, they are excellent extractants of thallium(I) picrates. The origin of cation‐binding is mainly discussed in terms of cavity size, the effects of substituents at the lower rim position and the replacement of methylene unit by S, and SO2.
Interaction between a Turbulent Flow and Reaction under Various Conditions in Oxygen Blown HYCOL Gasifiers
Authors: Liu Hao , Kojima Toshinori , Chen Caixia
Published: August 2010

With a three‐dimensional comprehensive computer simulation model, the effect of mixture fraction fluctuations on the overall gasification characteristics due to a turbulent flow was studied for gasification in oxygen blown HYCOL entrained‐flow coal gasifiers. The method compared the results with or without fluctuation of the gas‐mixture fraction. The theoretically predicted results were also compared with experimental data obtained from a 50 ton/day pilot‐scale HYCOL gasifier. It was seen that the fluctuation in mixture fraction of gases produced from devolatilization is just as important as that of char‐O2 reaction, i.e. neither of them can be neglected. They have an important influence not only on the temperature and gas composition distributions, but also on the cold gas efficiency and product gas composition. However, the fluctuations of gas‐mixture fractions produced from char‐CO2 and char‐steam reactions have only a limited effect. This conclusion is valid for a wide range of conditions of pressure, particle size and O2 concentration during entrained‐flow coal gasification. Based on these results, the simulation model can be simplified without significantly influencing the validity of the predicted results. The predictions that include fluctuations of mixture fractions show better agreement with the experimental data.
The Characteristics of Polyethylene Film for Stretch and Cling Film Applications
Authors: Small C.M. , Mcnally G.M. , Garrett G. , Murphy W.R.
Published: August 2010

Part I. A range of polyethylene films were prepared from metallocene linear low density polyethylene (m‐LLDPE), linear low density polyethylene (LLDPE) and ultra low density polyethylene (ULDPE) resins, containing 0 and 8% polyisobutylene (PIB). FTIR, DSC and mechanical analysis techniques were used to investigate the effect of co‐monomer type, density and melt flow index (MFI) on the mechanical performance, orientation and crystallinity of these films. The study established that co‐monomer type and MFI were the greatest factors influencing mechanical performance and crystallinity. Crystallinity was found to be the most influential factor governing PIB migration in these films and this in turn was related to polymer type, density and MFI, High MFI, octene co‐monomer films exhibited the highest orientation, tear resistance and tack strength and would therefore be suitable for stretch film applications. Ultra low‐density polymers gave relatively low tack strength and poor overall mechanical performance.

Part II. A range of ethyl vinyl acetate (EVA)/m‐LLDPE/EVA co‐extruded films was manufactured, with vinyl acetate (VA) co‐monomer content of 6, 12 and 18% and PIB content from 0–20%. The films were aged at 45d̀C for up to 28 days, to enable tack (cling) development. The results show that film tack strength improved significantly with ageing. Increased VA concentration in the surface layer also showed significant improvement in film tack strength. The film tensile strength, elongation and tear properties in both machine direction (MD) and transverse direction (TD) were not significantly affected by increase in PIB concentration. However, increased VA content showed slight improvement in MD mechanical performance of the films, TD properties were relatively unaffected. Films with 12 to 18% VA in the surface layers produced high surface tack film and the mechanical performance of these films were comparable to mono‐layer polyethylenes. These films are suitable for stretch wrap applications and have reduced the overall concentrations of tack additives, though high VA films were more difficult to process.
The Effect of Orientation on Extrusion Cast Metallocene Polyethylenes and the Role of Processing Conditions in the Die Swell of Metallocene and Conventional Polyethylenes
Authors: Millar B.G. , Laughlin P. , Murphy W.R. , Mcnally G.M.
Published: August 2010

Cast films were prepared from a range of metallocene polyethylenes (mPEs) of varied co‐monomer types (hexene, octene) using a Killion single‐screw extruder, using different haul off speeds (8–4 m/min) and die gaps (700–250 m̈m). Samples with greater orientation in one direction had increased tensile strength and shrinkage in that direction. DSC analysis showed crystallinity to decrease with decreasing haul of speed. Extrusion of mPEs and conventional linear low density polyethylenes (LLDPEs) by single capillary rheology showed that die swell increased with increasing extrusion rate and decreasing melt temperature. Increased die swell was found for the broader molecular weight distribution (M.W.D.) LLDPEs and in the higher molecular weight resins. Furthermore, long chain branching was found to increase die swell.
The Effect of Co‐monomer Type on the Mechanical and Thermal Properties of Metallocene and Conventional LLDPEs
Authors: Walker S. , Mcnally G.M. , Martin P.J.
Published: August 2010

A range of metallocene and conventional linear low‐density polyethylenes (LLDPEs), with different material properties, were prepared by injection moulding. An assessment of the effect of cooling rate and polymer properties on the mechanical performance of the specimens was conducted to establish any significant correlations. Tensile results showed that hexane‐based metallocene (m)LLPDEs exhibited higher elongation to break while the Young's modulus of the materials was found to be more influenced by density. Impact results demonstrated that mLLDPEs have superior impact strength at room temperature over conventional LLDPEs. Rheological studies of the materials under high shear rates experienced in injection moulding, were performed to determine flow characteristics of the materials. Differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were used to study the influence of the co‐monomer type and degree of branching on the properties of the materials.