bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface Tensions of Hydrocarbons and Bitumens at High Temperatures and Pressures
Authors: Millette Jacques , Scott Donald S. , Radlein Desmond , Piskorz Jan , Majerski Piotr , Reilly Irvine G. , Debruijn T. J. W. 
Published: July 2010

AbstractA maximum bubble pressure apparatus, described in a previous publication, has been used at pressures to 13.9 MPa (2000 psig) and temperature to 623 K (350°C) to measure the static surface tension of several alkanes and paraffinic petroleum fractions, and two types of Alberta bitumens in contact with hydrogen, helium and hydrogen/methane mixtures. With hydrogen, the surface tensions of alkanes or mixtures of alkanes were nearly independent of pressure, whereas with helium surface tension increased significantly. With hydrogen/methane mixtures, the surface tension decreased in value as pressure increased, with the effect increasing at the higher methane concentrations. For the two bitumens used, the surface tension with hydrogen showed a 10–15% increase as pressure increased at constant temperature. Some discussion is also given concerning methods of predicting the effects of pressure and temperature in hydrogen/hydrocarbon systems.
Pressure Fluctuations in Jet Spouted Beds
Authors: Leu Lii‐Ping , Pan Rong‐Shyan 
Published: July 2010

AbstractJet spouted beds that consisted of a transparent Plexiglas cylindrical column of 1 m high and a conical base with cone angles of 30°, 36°, and 40° were used in this study. The particles used were spherical glass beads with an average diameter of 1.7, 2.1 and 3 mm, respectively, and particle size of 2.2 – 3.1 mm, non‐spherical rice particles. The effect of size and shape of particles, and static bed height on the minimum jet spouting velocity, and standard deviation of pressure fluctuations, was investigated. The results show that the minimum jet spouting velocity and pressure drop increased as the bed height and particle size increased. The minimum jet spouting velocity could be determined from the plot of standard deviation of pressure fluctuations vs. superficial gas velocity. The results obtained were in close agreement with the results of other methods in the literature.
Homogeneous Fluidization Characteristics of Vibrating Fluidized Beds
Authors: Jin Haibo , Tong Zemin , Zhang Jiyu , Zhang Bijiang 
Published: July 2010

AbstractThe effects of vibration parameters, operating conditions and material properties on fluidization quality were investigated by the measurement and analysis of voidage fluctuation signals in a vibrating fluidized bed with a diameter of 148 mm. The fluctuation deviation of the bed voidage and the enhancement index of the bed derived can describe bed homogeneity and its extension. A new criterion of homogeneity, consisting of the material parameter (Ar), operating parameters (H0, u/umf) and vibration parameters (a, ω), is proposed to predict a suitable range of homogeneous fluidization. Experimental results on eight kinds of solids, five static bed heights and different vibration parameters were used to propose guidelines for the reasonable selection of operating conditions for vibrating fluidization and better operating conditions.
Effect of Non‐Newtonian Characteristics on Convective Liquid‐Solid Heat Transfer in Packed and Fluidised Beds of Spherical Particles
Authors: Shukla Rupali , Chhabra R. P. 
Published: July 2010

AbstractIn this work, the field (continuity, momentum and thermal energy) equations togetherwith a cell model have been solved numerically to elucidate the influence of non‐Newtonian (Power law rheology) liquid characteristics on liquid‐solid heat transfer in packed and fluidised beds of spherical particles. The results presented herein relate to wide ranges of conditions of bed voidage, power‐law index and Peclet number but are limited to low Reynolds number (≤1) flow conditions. Within the range of conditions, the effect of power‐law index is found to be small and this is also consistent with the available experimental results on liquid‐solid mass transfer in these systems.
Efficient Phase Equilibrium Calculation in a Reduced Flash Context
Authors: Nichita Dan Vladimir , Minescu Florea 
Published: July 2010

AbstractA new and efficient method for phase equilibrium calculations using cubic equations of state (EOS) has been developed. The reduced flash technique presented here takes into account non‐zero binary interaction coefficients (BIC's), and requires the iterative correction of a reduced number of independent variables (2m+3, where m is the number of components with non‐zero BIC's), irrespective of the number of components in the mixture. A new extrapolation procedure, called the Direct Reduced Flash Calculation (DRFC) is formulated. Calculations performed for several hydrocarbon mixtures with emphasis to the near‐critical region prove the robustness and the efficiency of the proposed method.
Fault Detection and Diagnosis in a Food Pasteurization Process with Hidden Markov Models
Authors: Tokatli Figen Kosebalaban , Cinar Ali 
Published: July 2010

AbstractHidden Markov Models (HMM) are used to detect abnormal operation of dynamic processes and diagnose sensor and actuator faults. The method is illustrated by monitoring the operation of a pasteurization plant and diagnosing causes of abnormal operation. Process data collected under the influence of faults of different magnitude and duration in sensors and actuators are used to illustrate the use of HMM in the detection and diagnosis of process faults. Case studies with experimental data from a high‐temperature‐short‐time pasteurization system showed that HMM can diagnose the faults with certain characteristics such as fault duration and magnitude.
The Effects of Power Law Fluid Rheology on Coil Heat Transfer for Agitated Vessel in the Transitional Flow Regime
Authors: Ricci Eric , Kelly William J. 
Published: July 2010

AbstractA CFD model of heat transfer from power‐law fluids to helical cooling coils in the transitional flow regime of a baffled tank mixed with a pitched blade turbine was developed with FluentTM. The model captured local temperature and velocity gradients. Simulations were run, varying Re, Pr, K and n. The results indicate that a Sieder‐Tate type correlation, with the exponent on and the coefficient in front of the Reynolds number being a function of n, is recommended for estimating ho. Also, a new two coil bank design was found to be more efficient when 450 < Re < 650.
The Impact of Local Phenomena on Mass Transfer in Gas‐Liquid Systems
Authors: Bork Olaf , Schlueter Michael , Raebiger Norbert 
Published: July 2010

AbstractThe impact of local phenomena on mass transfer from single bubbles and bubbles rising under swarm conditions with the bubble diameter and the viscosity as variation parameters is investigated by using laser‐induced fluorescence. It is reported that the wake shedding frequency of ellipsoid bubbles is decisively responsible for the convective mass transfer. A novel mass transfer correlation is developed considering the Strouhal number and swarm conditions.
Heat Removal from Reverse Flow Reactors Used in Methane Combustion
Authors: Balaji Sukumar , Lakshminarayanan S. 
Published: July 2010

AbstractThe idea of using Reverse Flow Reactors (RFR) for methane reduction in exhausts has been well elucidated in the past. However, there are intricacies in such operations to maintain the ignited state of the reactor along with maintaining low outlet concentrations of methane. This is especially true under rich feed conditions where combustion reactions liberate more heat leading to possible catalyst deactivation. Under favourable conditions, it is possible to continuously extract heat from the RFR system‐this is a viable way of maintaining acceptable thermal conditions in the reactor and consequently retaining catalyst activity. This paper elaborates upon the optimal amount of heat that can be removed from the system without losing the sustainability while preventing overheating of the catalyst bed. A simple event based control strategy is implemented for switching the inlet and outlet ports (flow reversal). Issues relating to the operation of reverse flow reactors with side feeding and the possibility of extraction of useful heat from such systems are also discussed. Methane combustion reaction and a continuous two dimensional heterogeneous model of the reactor have been employed in this study.
Simulation of Radiation Field in Multilamp Photoreactor Using the LSDE Model
Authors: Yang Quan , Pehkonen S. O. , Ray Madhumita B. 
Published: July 2010

AbstractDetermination of a radiation field in a multilamp photoreactor is rather difficult due to the blockage of light by the neighbouring lamps in the reactor. Shadow zones in the photoreactor caused by the lamp blockage vary according to the different lamp arrangements. In addition, the reactor shape also has an effect on the average light intensity, since light is absorbed by the reactor wall if it reaches the wall. In this study, selected aspects of reactor configuration and lamp arrangement were investigated in order to achieve the maximum average light intensity. A line source with a diffused emission (LSDE) model, which shows sufficient accuracy and simplicity, was selected to simulate the light field in the test reactor. Simulation indicates that the square and cylindrical reactors with two and four lamps installed symmetrically exhibited superior performance to elliptical and rectangular reactors. For a multilamp reactor, a triangular pitch of lamp arrangement with 33° is recommended for maximum average light intensity.
A Comparison of PID Controller Tuning Methods
Authors: Foley Michael W. , Julien Rhonda H. , Copeland Brian R. 
Published: July 2010

AbstractThe derivative mode is often omitted in PID control strategies because it proves difficult to arrive by trial‐and‐error at a set of constants which meet plant requirements. The primary objective of this paper was to evaluate several model‐based PID tuning methods. For lag‐dominant processes, it was recommended that the SIMC algorithm first be employed to determine whether satisfactory performance can be obtained with PI control. If it cannot, then derivative action should be introduced using the DS‐d technique. For delay‐dominant systems, IMC tuning is preferred. It was observed that when configured with the same derivative filter factor, the series form of the PID controller produces smoother valve adjustments than the parallel version, at the expense of a slight decrease in best achievable performance. Increasing this parameter improves the control effort but limits achievable performance.
Méthodologie d'étude et de modélisation de la déphosphatation d'effluents aqueux
Authors: Montastruc L. , Domenech S. , Pibouleau L. , Azzaro‐Pantel C. 
Published: July 2010

AbstractEn raison de l'impact des phosphates sur la pollution des eaux, un procédé de récupération par précipitation d'un phosphate de calcium a été développé. Le réacteur du procédé est un lit fluidisé, dans lequel le phosphate précipite en continu et s'enrobe sur des grains de sable. Le pilote réalisé permet de traiter des débits de rejet aqueux synthétique ([P]in = 50 mg/l) de l'ordre de 0,1 m3/h. La méthodologie découple les phéno‐mènes physico‐chimiques présents. La précipitation dans le lit fluidisé est modélisée à l'aide de concepts thermodynamiques tenant compte des différents phosphates de calcium susceptibles de précipiter en fonction des conditions opératoires (pH, [P], [Ca], T). L'enrobage est modélisé par une réaction cinétique du premier ordre entre les fines et les grains de sable, couplée avec un réseau de réacteurs idéaux traduisant l'hydrodynamique du système.
The Effect of Particle Size Distribution on Pressure Drop through Packed Beds of Cooked Wood Chips
Authors: Lee Quak Foo , Bennington Chad P. J. 
Published: July 2010

AbstractThe pressure drop of process liquors through columns of wood chips determines the operability, efficiency and control of both batch and continuous pulp digesters and the quality of the pulp produced from them. Pressure drop was measured through columns of industrial white spruce chips (produced with a chipping head‐rig) as a function of the chip size distribution and the extent of delignification. Flow resistance depended on the porosity of the chip bed which was affected by the kappa number of the chips (which affected their flexibility) and chip size distribution, the compaction forces applied to the column, and the liquid superficial velocity. The chip beds were compressible and inelastic. Previous work from the literature using the Ergun equation to characterize pressure losses through chip beds is examined and compared with results of this work.
Décantation assistée par ultrasons des eaux résiduaires
Authors: Augis Nicolas , Hus Philippe , Thivel Pierre‐Xavier , Viau Jean‐Yves 
Published: July 2010

AbstractCette étude consiste à mettre en évidence l'impact des ultrasons sur le traitement des eaux par décantation. Elle a permis d'une part, d'identifier les effets déjà mesurés des ultrasons sur les propriétés de décantabilité de différents effluents et d'autre part, d'observer ces effets lors d'une étude statique puis dynamique. Des conditions de sonification favorables à l'optimisation d'un tel procédé ont été déterminées. Les résultats mettent en évidence le rôle fondamental joué par les systèmes d'ondes stationnaires dans l'amélioration de la décantabilité des effluents (floculés ou non, de synthèse ou réels). Dans le cas d'effluents floculés, un impact réel sur la décantation est visible.
A Novel Predictive Technique for Estimating the Hydrate Inhibition Effects of Single and Mixed Thermodynamic Inhibitors
Authors: Mohammadi Amir H. , Tohidi Bahman 
Published: July 2010

AbstractA new correlation has been developed for predicting hydrate inhibition characteristics, as well as water freezing point depression of aqueous solutions containing salts and/or organic inhibitors. The correlation has been developed using hydrate inhibition/freezing point depression data at different concentrations of salt and/or organic inhibitor generated using a previously reported thermodynamic model. Independent data have been used in examining the reliability of this method. The predictions of this correlation are in acceptable agreement with the independent experimental data, demonstrating the reliability of this predictive technique for estimating the hydrate inhibition effects of salts and/or organic inhibitors.
Phase Equilibria for Ternary Liquid Systems of (Water + Carboxylic Acid + 1‐Heptanol) at 293.15 K: Modelling Considerations
Authors: Senol Aynur 
Published: July 2010

AbstractLiquid‐liquid equilibrium data of the solubility curves and tie‐line end compositions are presented for mixtures of [water (1) + formic acid, or acetic acid, or propanoic acid (2) + 1‐heptanol (3)] at T = 293.15 K and P = (101.3 ± 0.7) kPa. The properties and liquid‐liquid equilibria (LLE) of associated ternary systems have been correlated using a solvatochromic approach SERLAS. The tie‐lines were also predicted using the UNIFAC‐original model. The proposed model appears to be an improvement in data fit for the ternary systems yielding a mean error of 3.8% for all the systems considered.
Dry‐Reforming of Ethanol in the Presence of a 316 Stainless Steel Catalyst
Authors: De Oliveira‐Vigier K. , Abatzoglou N. , Gitzhofer F. 
Published: July 2010

AbstractDry‐reforming is a known process for the production of synthetic gas from natural gas or other volatile fossil fuels. Another possible application is the reforming of hydrocarbons contained in the synthetic gas produced from biomass or waste gasification. The absence of wide industrial process applications is mainly due to the high endothermicity of the reactions involved and technical problems associated with carbon formation. In this work, the target reaction is:

The principal challenge is that of using a 2D catalyst formulation favouring the target reaction and permitting easy retrieval of deposited carbon while, at the same time, preserving the catalyst's activity and structural integrity.This paper presents the results obtained from the use of a 316 stainless steel catalyst. The catalyst is active in ethanol dry reforming as the yield of hydrogen reached 98% of the theoretical value. Moreover, the co‐product carbon is of a filamentous form and can be easily retrieved without risk of modification to the catalyst properties. This catalyst is recyclable; it can be used several times over in the dry‐reforming of ethanol process without detectable change in its activity and selectivity.
Analytic Expressions of Ultimate Gains and Ultimate Periods with Phase‐Optimal Approximations of Time Delays
Authors: Lee Jietae , Park Ho Cheol , Sung Su Whan 
Published: July 2010

AbstractUltimate gains and ultimate periods have long been used to tune PI/PID controllers since the Ziegler‐Nichols tuning. Recently, very simple analytic equations for ultimate gains and ultimate periods by approximating the arctangent function have been presented, which can be used to obtain simple tuning rules. Here, by applying the Routh stability method and phase‐optimal approximations of the time delay term, we present analytic expressions of ultimate parameters that are as simple as the existing ones, showing better accuracy.
Three‐Dimensional CFD Simulation of Stratified Two‐Fluid Taylor‐Couette Flow
Authors: Vedantam Sreepriya , Joshi Jyeshtharaj B. , Koganti Sudhir B. 
Published: July 2010

AbstractTwo‐fluid Taylor‐Couette flow, with either one or both of the co‐axial cylinders rotating, has potential advantages over the conventional process equipment in chemical and bio‐process industries. This flow has been investigated using three‐dimensional CFD simulations. The occurrence of radial stratification, the subsequent onset of centrifugal instability in each phase, the cell formation and the dependency on various parameters have been analyzed and discussed. The criteria for the stratification, Taylor cell formation in each phase have been established. It can be stated that the analysis of single‐phase flow acts as the base state for the understanding of radial stratification of the two‐fluid flows. The extent of interface deformation also has been discussed. A complete energy balance has been established and a very good agreement was found between dissipation rate by CFD predictions and the energy input rate through the cylinder/s rotation.
Mass Transfer and Bioremediation of Naphthalene and Methyl Naphthalenes in Baffled and Bead Mill Bioreactors
Authors: Yu Ruihong , Nemati Mehdi , Hill Gordon , Headley John 
Published: July 2010

AbstractMass transfer and bioremediation of naphthalene, 2‐methylnaphthalene and 1,5‐dimethylnaphthalene have been studied in a rotating bioreactor modified with the addition of baffles and beads. Mass transfer rates of these low solubility organic particles dissolving in water (based on the working volume of the bioreactor) were highest in the bioreactor that combined beads and baffles, with the overall mass transfer coefficient (KLa) reaching up to 25 h−1. Based on its capacity to hold the largest volume of polluted media, the simple baffled bioreactor was considered to be the optimum roller bioreactor design. Using Pseudomonas putida, the bioremediation rate of naphthalene reached 61 mg/l‐h in this vessel and using mixed substrates, the bioremediation rate of 2‐methylnaphthalene reached 30 mg/l‐h. The dissolution rates for hydrophobic particles into the culture media during the bioremediation process were up to four times higher compared to mass transfer rates into abiotic controls, which was likely due to the production of biosurfactants by P. putida.
Steady Flow of Power Law Fluids across a Circular Cylinder
Authors: Bharti Ram Prakash , Chhabra R. P. , Eswaran V. 
Published: July 2010

AbstractThe momentum equations describing the steady cross‐flow of power law fluids past an unconfined circular cylinder have been solved numerically using a semi‐implicit finite volume method. The numerical results highlighting the roles of Reynolds number and power law index on the global and detailed flow characteristics have been presented over wide ranges of conditions as 5 ≤ Re ≤ 40 and 0.6 ≤ n ≤ 2. The shear‐thinning behaviour (n < 1) of the fluid decreases the size of recirculation zone and also delays the separation; on the other hand, the shear‐thickening fluids (n > 1) show the opposite behaviour. Furthermore, while the wake size shows non‐monotonous variation with the power law index, but it does not seem to influence the values of drag coefficient. The stagnation pressure coefficient and drag coefficient also show a complex dependence on the power law index and Reynolds number. In addition, the pressure coefficient, vorticity and viscosity distributions on the surface of the cylinder have also been presented to gain further physical insights into the detailed flow kinematics.
A Quantitative Measure to Evaluate Competing Designs for Non‐linear Dynamic Process Identification
Authors: Rollins Derrick K. , Pacheco Liza , Bhandari Nidhi , Nguyen Justin 
Published: July 2010

AbstractThe strategy for the collection of information (i.e., data) for model development is called experimental design. Optimal design seeks to maximize the information content under constraints of time and sampling. In the system identification literature the dominant strategy has been the method of pseudo random sequences (PRS). However, this work demonstrates that statistical design of experiments (SDOE) can provide greater information content as quantitatively measured by the D‐optimal criterion.
A Mortality Model for Penicillium bilaiae Subjected to Convective Air Drying
Authors: Friesen T. , Hill G. , Pugsley T. , Holloway G. 
Published: July 2010

AbstractDrying of microbial cells for storage purposes is a widely practised technology. A new statistical model is proposed for survivability of microbial cells during convective air drying, where mortality is predicted by hazard functions and acceleration factors applied to temperature, moisture content and drying rate variables. The model is based on experimental survivability data generated from drying Penicillium bilaiae conidia at temperatures from 20 to 60°C and air relative humidities from 3 to 75%. Experimental data using “one at a time” variable manipulation was used to obtain five model parameters. Despite several simplifications to reduce the number of variable cross‐dependencies, the model was successfully validated using combined stress trials with maximum deviations of ±15%.
Biosorption of Phenol onto Posidonia oceanica (L.) Seagrass in Batch System: Equilibrium and Kinetic Modelling
Authors: Ncibi Mohamed Chaker , Mahjoub Borhane , Seffen Mongi 
Published: July 2010

AbstractIn this research, the biosorption of phenol using the fibres of a Mediterranean seagrass Posidonia oceanica (L.) was studied. Batch experimental procedures were made to investigate the ability of this novel marine biomass to remove phenol from aqueous phase. The influences of pH and contact time at different initial concentrations were evaluated. The results showed that biosorption capacity was enhanced using solution pH equal to 5.2. The modelling results showed that pseudo‐second‐order and Redlich‐Peterson models were found to be the most suitable to satisfactory describe the kinetic and equilibrium adsorption data, respectively.