bluuebunny/crossref_metadata_2025_split huggingface dataset:
Horizontal wells and steam‐assisted gravity drainage
Authors: Butler R. M. 
Published: March 2009

AbstractPetroleum can be produced more efficiently using horizontal wells instead of conventional wells. For a typical 16 hectare well spacing, the pressure drawdown is as small as one‐fiftieth of that for conventional wells.In some cases, where coning is a problem in conventional production, horizontal wells allow operation with much less coproduction of the displacing fluid.In the thermal recovery of bitumen and heavy oils, the Steam‐Assisted Gravity Drainage process with horizontal production wells allows the systematic sweeping of the reservoir with economic production rates and without steam bypass.This paper described and reviews the application of horizontal wells to the production of heavy crude oils and bitumen by both non‐thermal and thermal methods.
Application of the rotating disk method to the study of bitumen dissolution into organic solvents
Authors: Ulrich R. K. , Koppaiah M. K. , Majmudar V. K. 
Published: March 2009

AbstractThe rotating disk system is demonstrated as a tool for performing studies of the dissolution rate of bitumen into organic solvents. Mass transfer coefficients to the rotating disk are constant in position and time can be made comparable to coefficients for sand particles in agitated liquids by adjusting the rotation rate. Data is presented for bitumen dissolution into pentane, hexane, heptane, toluene and oleic acid. Increasing the level of dissolved bitumen in the solvent decreases the bitumen dissolution flux primarily due to the increase in solvent viscosity.
Kinetic modelling of the catalytic conversion of synthesis gas
Authors: Simard F. , Mahay A. , Jean G. , Delasa H. 
Published: March 2009

AbstractA kinetic study for the one‐step conversion of synthesis gas to gasoline on a ZnO–Cr2O3–ZSM‐5 catalyst is described. On this catalyst, three reactions are involved in the overall transformation of synthesis gas: the methanol synthesis, the conversion of methanol to hydrocarbons and the water–gas shift reaction. Under the operating conditions selected for the study, it was found that the water–gas shift was at equilibrium and the methanol was completely converted to hydrocarbons. Consequently, it was postulated that the kinetics of the limiting reaction step, the methanol synthesis on the ZnO–Cr2O3 component, was the one that controls the overall reaction rate. Three kinetic model equations describing the rate of synthesis gas conversion on the bifunctional catalyst, were considered to fit the data of the experimental runs performed in a Berty well‐mixed reactor. Those equations were derived under very special conditions where the methanol decomposition term could be neglected. It was also observed that in the kinetic equations a term involving the fugacity of CO2 was required to predict the rate properly. The catalyst deactivation was also taken into account in the analysis.
La décomposition thermique du n‐decane en présence de vapeur dceau vers 720°C
Authors: Billaud F. , Elyahyaoui K. , Baronnet F. 
Published: March 2009

AbstractThe thermal degradation of n‐decane in a plug reactor is studied at about 720°C. Products not exclusively of primary type were all titrated using a gas phase capillary chromatography method. The major primary products are ethylene, methane, propene and hydrogen. Ethylene selectivity is approximately 35% at lower passage times (40 to 160 ms). A chain radical‐based theoretical mechanism has been used to account for all reaction products qualitatively and to represent the associated stoichiometrics for the degradation of initial alcane.
Effect of sulfite on reduction kinetics of Fe(III)NTA chelate
Authors: Sada E. , Kumazawa H. , Suchecki T. T. 
Published: March 2009

AbstractThe reduction of Fe(III)NTA (ferric ion coordinated to nitrilotriacetic acid) by sulfite has been found to be first‐order with respect to Fe(III)NTA and of order minus one with respect to Fe(II)NTA (one of the reaction products). The order of reaction with respect to HSO−3 has been determined to be unity when the molar ratio of Na2SO3 to total Fe(III) is less than five. In this paper, the role of sulfite in the reduction scheme is reconsidered, and the reduction rate expression in which the coordination of Fe3+ to HSO−3 is incorporated, is newly presented. The proposed rate equation covers all reaction data for molar ratios of Na2SO3 to total Fe(III) in the range of 1 to 25.
Mass transfer and holdup in gas‐liquid cocurrent flow packed beds containing water‐repellent particles
Authors: Goto Shigeo , Saikawa Keichiro , Gaspillo P. D. 
Published: March 2009

AbstractWater‐repellent particles were prepared by spraying polytetrafluoroethylene (PTFE) on activated carbon. Gas‐liquid volumetric mass transfer coefficient and holdup were determined in gas‐liquid cocurrent upflow and downflow packed beds from the measurements of gas desorption and volume, respectively. As the PTFE loading increased, the gas‐liquid volumetric mass transfer coefficients in both upflow and downflow modes were enhanced. Gas holdup in the upflow mode increased with the PTFE loading, while the dynamic liquid holdup in the downflow mode decreased. The enhancement of the mass transfer rate from gas to liquid can be explained by the effect of water‐repellency on the surface of activated carbon.
Solids distribution in slurry flow in a linear manifold with a horizontal approach
Authors: Foster J. , Nasr‐El‐Din H. A. , Masliyah J. H. 
Published: March 2009

AbstractAn experimental study was conducted to examine solids distribution in branches of a linear manifold having a horizontal approach. The manifold was designed to maintain approximately a constant slurry velocity upstream of each branch. Solids concentration in the branches was measured for various manifold orientations (upwards, side and downwards) and upstream conditions.Semi‐empirical correlations for the three orientations were developed to predict a branch concentration ratio. This ratio was dependent upon the branch flow ratio, the particle inertia parameter and the vertical solids concentration profile upstream of the branch. The agreement between the experimental and the predicted branch concentration ratio was fairly good.
The catalytic hydrotreatment of peat pyrolysate oils
Authors: Oasmaa Anja , Boocock David G. B. 
Published: March 2009

AbstractA 65 wt % yield of hexane‐soluble liquid, containing 83% of the feed carbon, was obtained when Finnish Carex‐peat pyrolysate was hydrotreated batchwise (21.5 MPa for two hours at 390°C with 10 wt % catalyst, 4% CoO/15.5% MoO3 on γ‐alumina). Oxygen content was lowered from 22% to 3% in the process. Nitrogen and sulphur contents of the product were 4.3% and 0.10%, respectively. Straight‐chain material predominated in the upgraded product and C14‐C29 n‐alkanes have been identified along with some phenols. The peat pyrolysate is also predominantly straight‐chain material, but contains polar functionalities such as the carboxyl group.
The behaviour of large gas bubbles at a liquid‐liquid interface. Part 2: Liquid entrainment
Authors: Shaw J. M. , Konduru R. 
Published: March 2009

AbstractThe roles played by large gas bubbles in the generation and coalescence of liquid drops at a liquid‐liquid interface are elucidated. The amount of lower liquid entrained by individual bubbles and the resulting drop size distributions in the upper liquid phase are quantified for the three phase system: sunflower oil + 50 wt % decane, water + 50 wt % sugar, air, and qualitative theoretical models are presented. Drops settling to the interface were found to coalesce rapidly and bubble flux had no apparent effect on the rate of drop coalescence at the liquid‐liquid interface.
An improved characterization method for petroleum fractions
Authors: Jabr N. , Alatiqi I. M. , Fahim M. A. 
Published: March 2009

AbstractAn improved characterization of naphtha can be obtained by assuming representative chemical components for each cut and utilizing an empirical model to predict the physical and thermodynamic properties such as critical properties, molar mass, refractive index, enthalpy of vaporization, viscosity, etc. The improved model for feed characterization utilizes a multivariable constraint optimization technique in order to arrive at the properties of the blend. It was found that this model does improve the accuracy of prediction.An application is presented for a naphtha blending system and a naphtha debutanizer. The sensitivity of the column simulation to the developed feed characterization method has been investigated by digital simulation. With the boiling point model, large deviations from the actual column performance data have been observed while a farily good match has been obtained with the improved model.
An expert system for selecting a vapour‐liquid contactor
Authors: Chuang K. T. , Chen G. X. , Rao M. 
Published: March 2009

AbstractAn expert system for selecting a vapour‐liquid contactor (SVLC) is described in this article. The objectives of this study are to investigate the potential application of expert systems to chemical process design, and to capture and codify human design expertise into computer programs. The SVLC is constructed by combining numerical computations with symbolic reasoning processes based on human expertise and available separation technology. It can help design engineers select a vapour‐liquid contactor by following existing rules. Six most commonly used contactors (sieve, valve, bubble cap and dual flow tray as well as random and structured packing) were considered. The results show that the final selections are consistent with those practised in industry.
Scrubbing of SO2 with trona solution in a spray drier
Authors: Doĝu Gülsen , Uçar Çiĝdem , Doĝu Timur , Gürüz Güniz , Durmaz Ali , Ercan Yücel 
Published: March 2009

AbstractEffect of operating variables on the scrubbing efficiency of SO2 in a spray drier was investigated using trona (Na2 CO3 · NaHCO3 · 2H2 O) solutions of different compositions. Results indicated that for a Na/S mole ratio of two (stoichiometric ratio) about 80% of the SO2 was removed. For higher Na/S ratios, SO2 removal efficiency increased by up to 100%. Increased SO2 concentration in the feed gas and decreased outlet temperature caused an increase in the overall conversion. At low temperatures and low SO2 concentration, the reaction takes place mainly between SO2 and Na2 CO3 As the temperature is increased, decomposition of NaHCO3 to Na2 CO3 and sorption reactions take place simultaneously.
A new technique for determining the hydrodynamic characteristics of spouted beds
Authors: Cai P. , Dong X.‐R. , Jin Y. , Yu Z.‐Q. 
Published: March 2009

AbstractA new technique was developed to determine the hydrodynamic characteristics of spouted beds. Under different operating conditions, this technique exploits the similarity of the voidage signals from different locations of the bed by means of coherence functions. The spout diameter as well as the minimum spouting velocity and maximum spoutable bed depth can be quantified by the values of the average coherence functions. The new approach presented in this paper is featured by its convenience and accuracy. It is eminently suitable for large size 3‐dimensional units which can not be visibly observed.
The mean flow field produced by a 45° pitched blade turbine: Changes in the circulation pattern due to off bottom clearance
Authors: Kresta Suzanne M. , Wood Philip E. 
Published: March 2009

AbstractThe impeller discharge stream and bulk circulation flow produced by a pitched blade turbine (PBT) in a fully baffled stirred tank have been defined, using a combination of flow visualization and laser Doppler anemometry measurement techniques. Two distinct bulk circulation patterns have been identified, one for higher off bottom clearances, and one for lower clearances. The circulation patterns are shown to have a substantial impact on the discharge stream, even very close to the edge of the impeller blades. These findings indicate that the action of the impeller is not independent of the tank geometry, but contains a substantial feedback component from the bulk flow. This conclusion has substantial implications for the modelling and prediction of stirred tank flow fields.
Transient forced convection in the entrance region of a porous tube
Authors: Al‐Nimr M. A. , Aldoss T. , Naji M. I. 
Published: March 2009

AbstractThe problem of transient forced convection in the entrance region of a cylindrical porous medium with developing thermal boundary layer is investigated. The hydrodynamic behaviour of the flow is assumed to be steady and fully developed, and both Darcian and non‐Darcian effects on the flow are considered. Thermal transients are created by a step change in the temperature of the tube wall. The effect of different fluid and solid‐matrix parameters on Nusselt number, thermal entrance length, total heat absorbed and mixing cup temperature are considered.
Kinetic study of the reaction between molybdenum trioxide and gaseous carbon tetrachloride
Authors: Ruiz M. Del C. , Rivarola J. B. , Quiroga O. D. 
Published: March 2009

AbstractThe kinetics of the chlorination reaction of molybdenum trioxide with gaseous carbon tetrachloride has been studied at temperatures between 713 and 753 K.The effects of temperature, reaction time, residence time and gaseous reactant concentration on conversion were studied throughout the reaction. In all cases, there was an increase in conversion when the above operating variables were increased.The kinetic model proposed is consistent with and correlates the experimental data. In the range studied for the different variables, the step that controls the rate of reaction is the surface chemical reaction. Values of the rate constant and the activation energy were estimated.
Pressure drop for the slow flow of dilatant fluids through a fixed bed of spherical particles
Authors: Jaiswal A. K. , Sundararajan T. , Chhabra R. P. 
Published: March 2009

AbstractThe equations of motion in conjunction with the free surface cell model have been solved numerically for the creeping flow of dilatant fluids through a fixed bed of spheres. The effect of the flow behaviour index (1 ≤ n ≤ 2) on the individual as well as the total drag coefficients is elucidated. Finally, the theoretical predictions have been validated using the scant experimental results available in the literature.
A rheological evaluation of linear and branched controlled‐rheology polypropylenes
Authors: Tzoganakis Costas 
Published: March 2009

AbstractCommodity linear and branched polypropylene resins have been modified by means of peroxide initiated chemical degradation in a reactive extrusion process. Data collected from molar mass and linear viscoelastic property measurements have been used to evaluate the L“crossover modulus” and “modulus separation” rheological polydispersity measures and a theoretical justification is provided for the modulus separation index. In the past, these empirical methods have been used successfully to relate molar mass characteristics to rheological properties. Results obtained in this study confirm the validity of the modulus separation index for linear polymers and suggest that it should be used carefully in the analysis of data from branched polymers. Linear viscoelastic data are used to estimate the terminal relaxation time spectra of both the linear and branched materials and a new correlation between modulus separation and relaxation time polydispersity is given.
The design of experiments, training and implementation of nonlinear controllers based on neural networks
Authors: Dayal Bhupinder S. , Taylor Paul A. , Macgregor John F. 
Published: March 2009

AbstractIn the area of nonlinear predictive control, several control schemes using artificial neural networks have been proposed. In this work, the issues relating to the information contents of the data used to train the neural network components of these nonlinear predictive control schemes are considered. This raises questions about the design of experiments. A class of feedback‐feedforward nonlinear controller based on the model predictive structure (also known as Internal Model Control, IMC, structure) is investigated. The implementation and performance of these neural network based controllers, together with comparisons to other nonlinear and linear controllers, are illustrated on two nonlinear continuous‐stirred‐tank‐reactor simulations.
GLUCOSE‐REGULATED PROTEIN 78 PROMPTS SCAVENGER RECEPTOR A‐MEDIATED SECRETION OF TUMOUR NECROSIS FACTOR‐α BY RAW 264.7 CELLS
Authors: Gao Song , Zhong Xiaozheng , Ben Jingjing , Zhu Xudong , Zheng Yuan , Zhuang Yan , Bai Hui , Jiang Li , Chen Yaoyu , Ji Yong , Chen Qi 
Published: March 2009

SUMMARY

Activation of macrophages plays an important role in atherosclerosis. In order to investigate the effect of endoplasmic reticulum (ER) stress on cytokine release from macrophages, the RAW 264.7 mouse macrophage cell line was treated with 0.2 mmol/L 6‐aminonicotinamide (6‐AN) for 36 h and the secretion of tumour necrosis factor (TNF)‐α determined. In addition, Raw 264.7 cells were incubated in the presence of 10 µg/mL acetylated low‐density lipoprotein (acLDL) at 37°C for 8 h.
Secretion of TNF‐α from RAW 264.7 cells was stimulated by both loading of cells with acLDL and following 6‐AN treatment. In addition, the expression of glucose‐regulated protein (GRP) 78 was increased in 6‐AN‐treated cells (by 165%).
In separate experiments, PD98059, a specific inhibitor of the mitogen‐activated protein kinase kinase (MEK) pathway, blocked acLDL‐ and/or 6‐AN‐induced TNF‐α secretion, whereas LY294002, which blocks the AKT signalling pathway, had no effect. On the basis of these results, we speculate that acLDL/6‐AN‐induced secretion of TNF‐α from RAW 264.7 cells may be regulated by activation of the MEK signalling pathway.
The present study suggests that the accumulation of lipids in cells and/or ER stress could lead to macrophage apoptosis as a result of the increased production of TNF‐α, which integrates into atherosclerosis.
FORMALIN‐INDUCED INCREASE IN P2X3 RECEPTOR EXPRESSION IN DORSAL ROOT GANGLIA: IMPLICATIONS FOR NOCICEPTION
Authors: Pan Ai‐Hua , Lu Da‐Hua , Luo Xue‐Gang , Chen Ling , Li Zhi‐Yuan 
Published: March 2009

SUMMARY

ATP‐gated P2X receptors in nociceptive sensory neurons participate in the transmission of pain signals from the periphery to the spinal cord. The effect of formalin on the expression of P2X3 receptors in dorsal root ganglia (DRG) was characterized using molecular and immunological approaches and the patch‐clamp technique.
Adult Sprague‐Dawley rats were injected with 100 µL of 5% formalin in the planar surface of the hindpaw and were killed 30 min and 1, 3, 6, 12, 24 and 48 h later for in vitro analyses. The expression and distribution of P2X3 receptors in the lumbar spinal cord and in L5/L6 DRG were examined; 24 and 48 h after formalin injection, currents in neurons were examined using whole‐cell patch‐clamp recording.
Western blots showed that anti‐P2X3 antibody recognized a major monomer of approximately 64 kDa in DRG. Immunoreactivity for P2X3 receptors was detected predominantly in the cytoplasm and plasma membrane of small (< 25 µm) and middle‐sized (25–50 µm) DRG neurons. Expression of the P2X3 transcript in the DRG was unchanged 30 min and 1 h after formalin injection, but increased after 12 h. There was no distinct change in P2X3 immunostaining of the spinal cord lamina at 30 min or 1 h after injection, but after 24 h P2X3 labelling increased. At 24 h after the formalin injection, currents in isolated small and middle‐sized DRG neurons were increased by 1 µmol/L α,β‐methylene‐ATP. These currents were completely inhibited by 1 µmol/L A‐317491, a potent and selective P2X3 receptor antagonist.
These data suggest that formalin injection leads to early upregulation of P2X3 expression in the spinal cord and DRG and that this may be one of the mechanisms giving rise to nociception.
BMI and Diabetes Risk in Singaporean Chinese
Authors: Odegaard Andrew O. , Koh Woon-Puay , Vazquez Gabrielle , Arakawa Kazuko , Lee Hin-Peng , Yu Mimi C. , Pereira Mark A. 
Published: March 2009

OBJECTIVE
Increased BMI is a robust risk factor for type 2 diabetes. Paradoxically, South Asians have relatively low BMIs despite their high prevalence of type 2 diabetes. We examined the association between BMI and incident type 2 diabetes because detailed prospective cohort data on this topic in Asians are scarce.

RESEARCH DESIGN AND METHODS
This study was a prospective analysis of 37,091 men and women aged 45–74 years in the Singapore Chinese Health Study, using Cox regression analysis.

RESULTS
Risk of incident type 2 diabetes significantly increased beginning with BMIs 18.5–23.0 kg/m2(relative risk 2.47 [95% CI 1.75–3.48]) and continued in a monotonic fashion across the spectrum of BMI. Results were stronger for younger than for older adults.

CONCLUSIONS
BMIs considered lean and normal in Singaporean Chinese are strongly associated with increased risk of incident type 2 diabetes. This association weakened with advanced age but remained significant.
Acute Effects of Decaffeinated Coffee and the Major Coffee Components Chlorogenic Acid and Trigonelline on Glucose Tolerance
Authors: van Dijk Aimée E. , Olthof Margreet R. , Meeuse Joke C. , Seebus Elin , Heine Rob J. , van Dam Rob M. 
Published: March 2009

OBJECTIVE
Coffee consumption has been associated with lower risk of type 2 diabetes. We evaluated the acute effects of decaffeinated coffee and the major coffee components chlorogenic acid and trigonelline on glucose tolerance.

RESEARCH DESIGN AND METHODS
We conducted a randomized crossover trial of the effects of 12 g decaffeinated coffee, 1 g chlorogenic acid, 500 mg trigonelline, and placebo (1 g mannitol) on glucose and insulin concentrations during a 2-h oral glucose tolerance test (OGTT) in 15 overweight men.

RESULTS
Chlorogenic acid and trigonelline ingestion significantly reduced glucose (−0.7 mmol/l, P = 0.007, and −0.5 mmol/l, P = 0.024, respectively) and insulin (−73 pmol/l, P = 0.038, and −117 pmol/l, P = 0.007) concentrations 15 min following an OGTT compared with placebo. None of the treatments affected insulin or glucose area under the curve values during the OGTT compared with placebo.

CONCLUSIONS
Chlorogenic acid and trigonelline reduced early glucose and insulin responses during an OGTT.