bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving Renaturation of Proteins from Inclusion Bodies
Authors: Kotlarski Nicholas , O'Neill Brian K. , Dunlop Eric H. , Francis Geoffrey L. 
Published: August 2010

AbstractThe 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

AbstractA 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

AbstractThe 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

AbstractOne 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.
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

AbstractA 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

AbstractA 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

AbstractA 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

AbstractThe 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

AbstractIn 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

AbstractWe 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

AbstractDifferent 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

AbstractParticle 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

AbstractExperiments 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

AbstractSyntheses 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

AbstractWith 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

AbstractPart 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

AbstractCast 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

AbstractA 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.