bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiographic measurement of tibial joint angles in sheep
Authors: Hette K. , Volpi R.S. , Pereira-Junior O.C.M. , Mamprim M.J. , da Silva V. Colombi , Rahal S.C. 
Published: March 2009

SummaryThe aim of this study was to establish normal reference values of anatomic and mechanical joint angles of the tibia in sheep at different age groups. Eighteen clinically healthy Santa Ines sheep were used. The animals were divided into three equal groups according to age: Group I – from six- to eight-months-old, Group II – 2-years-old, Group III – from three- to five-years-old. Anatomic medial proximal and lateral distal tibial angles, mechanical proximal and distal tibial angles, and anatomic caudal proximal and anatomic cranial distal tibial angles were measured from tibiae radiographs (n = 36). In the craniocaudal view, the mean values of the anatomic medial proximal, anatomic lateral distal, mechanical medial proximal, and mechanical lateral distal tibial joint angles were 89.6°, 86.6°, 91.4°, and 85.19° respectively. In mediolateral view, the mean values of the anatomic caudal proximal and anatomic cranial distal tibial angles were 64.55° and 105.69°, respectively. The joint orientation angles of the tibia in sheep showed similar values regardless of animal age for both anatomic and mechanical axes.
Selective iNOS-inhibition does not influence apoptosis in ruptured canine cranial cruciate ligaments
Authors: Hofer D. , Forterre S. , Schweighauser A. , Krayer M. , Doherr M. , Schawalder P. , Zurbriggen A. , Spreng D. 
Published: March 2009

SummaryAbnormal patterns of cell death, including increased apoptosis, can influence homeostasis of ligaments and could be involved in the pathogenesis of cranial cruciate ligament (CCL) rupture. Increased nitric oxide (NO) production has been implicated as a stimulus to increased apoptosis in articular cartilage. This study investigated apoptotic cell death in ruptured canine CCL (CCL group, n = 15), in ruptured CCL of dogs treated with oral L-N6-(1-iminoethyl)-lysine (L-NIL), a selective NO-synthetase(NOS)-inhibitor, (L-NIL group, n = 15) and compared the results with normal canine CCL (control group, n = 10).Orally administered L-NIL at a dosage of 25 mg/m2 of body surface area was effective in inhibiting NO production in the articular cartilage of dogs in the L-NIL group, but it did not significantly influence the increased quantity of apoptotic cells found in ruptured CCL specimens. The results of this study suggest that apoptosis of ligamentocytes in the canine CCL is not primarily influenced by increased NO production within the stifle joint.
Intensification of a vortex during free draining
Authors: Ramamurthi K. , Tharakan T. John 
Published: March 2009

AbstractThree regimes of air‐core vortex formation are demonstrated to exist for the free draining of liquids containing angular momentum. These comprise of a rapidly intensifying air‐core vortex, a quasisteady vortex and a decaying vortex. The regimes are shown to be strongly influenced by the size of the drain‐port used in relation to the tank diameter. The influence of Froude number on air‐core vortex is discussed.
Characterization studies of calcined, promoted and non‐promoted methanol‐steam reforming catalysts
Authors: Idem Raphael O. , Bakhshi Narendra N. 
Published: March 2009

AbstractVarious promoted methanol‐steam reforming catalysts were prepared by incorporating Mn, Cr and Zn promoters into two dried corprecipitated Cu‐Al catalyst precursors containing 24.1 and 27.8 mass% Cu, calcined at 700°C, and then subjected to various activation treatments. Both the calcined and activated catalysts were thoroughly characterized using reaction studies, ICP—AES, XRD and TPR techniques.Results showed that in addition to Cu2O, CuO, Al2O3 and CuAl2O4 species present in all calcined catalysts, calcined Zn‐promoted catalysts contained ZnO and ZnAl2O4 species, whereas calcined Mn‐ and Cr‐promoted catalysts contained CuMnO2 and Mn2O3, and Cu2Cr2O4 and Cr2O3 species, respectively. The nature and amounts of active sites generated on activated catalysts for the methanol‐steam reforming reaction strongly depended not only on the promoter type and concentration but also on the activation method.
Experimental investigation of phosphate dust collection in impinging streams (IS)
Authors: Berman Yuli , Tamir Abraham 
Published: March 2009

AbstractAn experimental study on collection of dry phosphate dust and coalescence of moistened phosphate dust in an Impinging‐stream (IS) collector has been conducted in the presence and in the absence of a water spray.The total collection efficiency with a water spray of specific consumption of 0.3 kg water/kg dust was 95–97%. Air velocity at the inlet pipes varied between 10–30 m/s and the inclination angle with respect to the horizontal, a, of the IS was 40−60°. The water spray increased the collection efficiency by 5–20% in comparison to dry collection.In the coaxial configuration, α = 0°, it has been obtained that in the presence of a water spray, up to 55–85% of the dust accumulated on the walls of the collector, which was undesirable. Applying the inclined IS decreased the above quantities up to 5–15% with an optimal inclination angle of α = 40°.A simple model for collection of the particles has been established, showing a satisfactory agreement with experimental results.
Diffusion coefficients of propane and butane in peace river bitumen
Authors: Das Swapan K. , Butler Roger M. 
Published: March 2009

AbstractDiffusion plays a vital role in the “Vapex” process. In the present work the results of experiments on “Vapex” using a Hele‐Shaw cell have been used to obtain empirical correlations for the diffusivities of propane and butane in Peace River bitumen. Additional data required for the estimation of diffusivities from these experiments are the solubilities of solvent in bitumen and a correlation for the viscosity of solvent bitumen mixture. Diffusivities are assumed to decline exponentially with viscosity. Computed values of diffusion coefficients fall within the range of the published data for similar systems. This simple experiment can be used to estimate the diffusivities of gaseous solvents in highly viscous fluids.
Recovery, characterization and conceptual modelling of Non‐Bituminous organic materials from oil sands
Authors: Sengupta Susmita , Tollefson Eric L. , Dalai Ajay K. 
Published: March 2009

AbstractThe hot water process has recovered approximately 90% of the bitumen in oil sands, but the remaining 10% of bitumen and naphtha has been lost to the tailings pond. Recovery of bitumen and non‐bituminous combustibles (NBC) from centrifuge, scroll and final tailings has been considered. The effects of four sequestering agents, and of chemical additives such as CaCl2 and FeCl3 on the flotation behavior of bitumen, NBC and minerals in these tailings have been investigated. A simple method of isolating NBC materials has been developed. The flotation of both bitumen and NBC was enhanced by phosphate treatment and depressed by EDTA. NBC was characterized by its physical properties, energy content, functionality and chemical analysis. A conceptual model explains the interactions between the bitumen, minerals and NBC fractions present in tailings slurries.
Conversion of canola oil to various hydrocarbons over Pt/HZSM‐5 bifunctional catalyst
Authors: Katikaneni Sai P. R. , Adjaye John D. , Bakhshi Narendra N. 
Published: March 2009

AbstractCanola oil conversion was studied at atmospheric pressure over Pt/HZSM‐5 catalyst (0.5 mass% Pt) in a fixed bed micro‐reactor. The operating conditions were: temperature range of 400−500°C, weight hourly space velocity (WHSV) of 1.8 and 3.6 h−1 and steam/oil ratio of 4. The objective was to optimize the amount of gasoline range hydrocarbons in the organic liquid product (OLP) and the selectivity towards olefins and isohydrocarbons in the gas product. The gas yields varied between 22–65 mass% and were higher in the presence of steam compared to the operation without steam. The olefin/paraffin mass ratio of C2‐C4 hydrocarbon gases varied between 0.31–0.79. The isohydrocarbons/n‐hydrocarbons ratio was higher with Pt/HZSM‐5 (1.6–4.8) compared with pure HZSM‐5 catalyst (0.2–1.0). The OLP yields with Pt/HZSM‐5 (20–55 mass% of canola oil) were slightly lower compared to HZSM‐5 (40–63 mass% of canola oil) under similar conditions. The major components of OLP were aliphatic and aromatic hydrocarbons. A scheme postulating the reaction pathways for the conversion of canola oil over Pt/HZSM‐5 catalyst is also presented.
Preparation of supported La0.66Sr0.34Ni0.3Co0.7O3 perovskite catalysts and their performance in methane and odorized natural gas combustion
Authors: Klvana D. , Kirchnerova J. , Gauthier P. , Delval J. , Chaouki J. 
Published: March 2009

AbstractThree industrially applicable forms of supported La0.66Sr0.34Ni0.3Co0.7O3 perovskite combustion catalyst were prepared: alumina pellets coated with perovskite powder, perovskite formed in situ on ceramic fibers, and perovskite formed in situ in fluidizable particles. Kinetics of methane combustion over these catalysts was determined in a plug‐flow reactor. For the fiber supported catalyst as the representative one, the effects of various operational conditions on the performance were evaluated in a CSTR Berty reactor. The combustion was inhibited by carbon dioxide, but water had no effect. No carbon monoxide was detected in the effluents even when combusting a methane‐rich mixture. No measurable effect of combusting commercial natural gas odorized by ∼10 mL/m3 methyl mercaptan was observed, although the catalyst was slowly deactivated by 150 mL/m3 mercaptan in the feed. A simple kinetic model which takes CO2 inhibition into account is proposed: r = k2 P/(1 + Kinh P).
Treatment of gases and dust using “droplet columns”
Authors: Botton R. , Benadda B. , Bressat R. , Otterbein M. 
Published: March 2009

AbstractThe properties of the air‐water state diagram, representing the liquid holdups according to gas velocities, in a 0.075 m diameter column are restated. After measurement of the interfacial areas and mass‐transfer coefficients, the part of the diagram corresponding to high gas velocities and low liquid contents (10 < UG < 14 m/s and 0.005 < UL < 0.04 m/s) was chosen for the treatment of polluted gas streams. Under these conditions, it was shown that a “droplet column” is very efficient for the treatment of gases polluted by acid vapors (SO2, HCl) and dust (iron oxide, talc, etc.). The cost of energy appeared more favorable than for classical bubble columns.
Critical impeller speed for solid suspension in gas inducing type mechanically agitated contactors
Authors: Saravanan K. , Patwardhan A. W. , Joshi J. B. 
Published: March 2009

AbstractCritical impeller speed for solid suspension (NCS), has been measured in gas inducing mechanically agitated contactors (GIMAC) fitted with two impellers. Five different impeller designs were employed. It was found that the multiple impeller system having both pitched blade downflow turbines was the most energy efficient for the suspension of solid particles. The interimpeller clearance (C3), and the impeller bottom clearance (C1) were found to be important parameters. Further, for this optimum combination, the design of the lower impeller was optimized in terms of impeller diameter (D), blade width (W), blade angle (A), and the number of blades (nb). An empirical model has been proposed based on the mechanism of fluidization.
Condensation en film entre deux plaques planes verticales: Comparaison des performances thermiques du R134a et du R12
Authors: Louahlia H. , Panday P. K. 
Published: March 2009

AbstractCet article présente les résultats d'une étude numérique sur la condensation par convection forcée du R134A entre deux plaques verticales. Le modèle physique est basé sur la résolution des équations de la couche limite en tenant compte des paramètres souvent négligés dans les études théoriques de la condensation, à savoir le gradient de pression, les termes d'inertie et de convection d'enthalpie, la variation des propriétés physiques ainsi que la viscosité et la conductivité turbulentes. Les résultats du présent calcul sont confrontés aux valeurs expérimentaux de Shao et Granryd (1995). Les performances thermiques du R12 et du R134a sont comparées. Les effets de la turbulence, de la pesanteur, de la vitesse de la vapeur, du nombre de Jakob, des forces de pression ainsi que des contraintes tangentielles sont également analysés.
Characterisation of three different impellers using the LDV‐technique
Authors: Tiljander Pia , Rönnmark Björn , Theliander Hans 
Published: March 2009

AbstractA characterisation of three commonly used impellers was made in this study by measuring local mean velocities and the fluctuations of these velocities with the LDV technique. The data was used to estimate volumetric flow, velocity fluctuations and turbulent intensity in the impeller region of the tank. The impellers investigated were a high flow impeller, a pitched blade turbine and a Rushton turbine. The cylindrical vessel used was made of Perspex, had a dished bottom (DIN 28013), was equipped with four baffles and had an inner diameter of 0.45 m.It was found that the bulk velocities could be scaled with the tip‐speed of the impeller (ND). The flow rate at constant impeller speed increased in the order high flow impeller — Rushton turbine — pitched blade turbine. The corresponding order for the turbulence fluctuation is: high flow impeller — pitched blade turbine — Rushton turbine. The velocity profile of the flow out from the high flow impeller was furthermore, not as smooth as could be expected.
The solubility of mixtures of H2S and CO2 in an mdea solution
Authors: Jou Fang‐Yuan , Otto Frederick D. , Mather Alan E. 
Published: March 2009

AbstractThe solubility of mixtures of hydrogen sulfide and carbon dioxide in a 50 mass per cent aqueous solution of methyldiethanolamine (MDEA) solution has been measured at 40°, 70° and 100°C. Partial pressures of the acid gases ranged from 0.08 to 10 450 kPa.
Électrodes poreuses percolées constituées de métal fritté: Hydrodynamique et transfert de matière
Authors: Vilar Eudésio Oliveira , Coeuret FrançOis 
Published: March 2009

AbstractOn a étudié des électrodes poreuses percolées constituées de nickel fritté du commerce, suivant différentes configurations (plaque percolée perpendiculairement; tube percolé radialement; tube traversé par un écoulement longitudinal, avec percolation radiale des parois). Après avoir caractérisé ces matériaux partir de mesures de pérmeamétrie, on a utilisé la méthode électrochimique de mesure des coefficients de transfert de matière pour atteindre la valeur des coefficients volumétriques de transfert de matière. Des correlations empiriques sont obtenues dans le cas des électrodes unidimensionnelles (électrode axiale, électrode radiale), et comparées à d'autres corrélations de la litérature. Les résultats obtenus dans le cas d'un écoulement axial combiné à une aspiration au travers de la paroi sont discutés.
Theoretical and experimental investigations of molecular migration and diffusion kinetics of organic esters into tetrafluoroethylene/propylene copolymer membranes
Authors: Aminabhavi Tejraj M. , Harlapur Sujata F. , Balundgi Ramachandra H. , Dale Ortego J. 
Published: March 2009

AbstractA theoretical analysis of the experimental results on the migration and diffusion kinetics of methyl acetate, ethyl acetate, n‐propyl acetate, n‐butyl acetate and iso‐amylacetate into tetrafluoroethylene/propylene copolymer membranes has been made. Diffusion and permeability coefficients have been calculated from Fick's equation. The concentration profiles of the liquids have been calculated from a solution of Fick's equation as well as using an empirical relation for the esters into the varying penetration depths of the membranes at different time intervals. The diffusion coefficients show a systematic decrease with increasing size of esters and the results are discussed in terms of the membrane‐solvent interactions.
A soft sensor for flotation plants
Authors: Bazin Claude , Trusiak Andrew 
Published: March 2009

AbstractA soft‐sensor was developed to estimate the solids flow rates in the streams of a flotation circuit. The algorithm uses metal assays and mass flow rate measurements to perform the estimation. The method performs a recursive least squares estimation of the mass flow rates based on the assumption of mass conservation over a specified time window. The soft‐sensor is programmed into a Vax computer system interfaced with a DCS and is currently used for process control and instrument tuning.
Autofluidization: The fluidization of solid particles by gases evolving from the particles
Authors: Lawrence A. David , Gogolek Peter E. , Kuang James 
Published: March 2009

AbstractAn experimental procedure was developed to study the autofluidization (i.e. the fluidization of solid particles by gases evolving from the particles) of green coke. It was found that the best method was to heat a 30 cm deep bed of 178 μm quartz sand to 800°C while fluidizing it with air and then adding a small batch of ˜1 mm coke particles to the surface of the bed. After allowing the coke to mix with the sand for 20 s, the fluidizing air was reduced to a lower rate. Pressure is then measured as a function of height in the bed and time. The result is a series of pressure measurements which decay smoothly from the fluidized state to a new steady state once all the coke's volatiles have been released. From these measurements it is possible to calculate gas velocities in the bed as well as bed voidage and apparent density. It was found that the upper sections of the bed would remain fluidized for up to nearly 2 min after the coke was added to the sand while the lower parts of the bed were never fluidized. Simple theory, in the form of the Blake‐Kozeny equation, does a good job of predicting when autofluidization will occur and what the changes in bed height and pressure are within the bed.
Non‐uniformity of gas dispersion in turbine‐generated viscoelastic circulation flow
Authors: Vlaev Serafim D. , Martinov Martin 
Published: March 2009

AbstractGas dispersion has been analysed experimentally by measuring local gas hold‐up in two lab‐scale conventional turbine‐agitated vessels loaded with viscoelastic fluids. The gas hold‐up radial profiles obtained in various axial positions close and far from the impeller reveal high non‐uniformity of gas dispersion. Non‐uniformity is quantified and related to elasticity, shear dependent viscosity, shear rate, first normal stress difference coefficient and type of fluid. The low values of gas hold‐up obtained for the vessel central area are interpreted as hindered gas dispersion caused by the flow pattern specific for the viscoelastic properties of the circulating fluid. The paper is complementary to the effort for collecting up data for benchmarking numerical CFD simulations (Kumar et al., 1997).
Demixing effects in laminar shearing flows: A practically useful approach
Authors: Agarwal Sushant , Gupta Rakesh K. , Doraiswamy Deepak 
Published: March 2009

AbstractThe phenomena of shear‐induced agglomeration and shear‐induced migration in a non‐ colloidal particulate suspension were examined in different flow fields. The shear flow of a model suspension consisting of spherical glass beads in an aqueous corn syrup with added surfactant was studied in homogeneous and non‐homogeneous flow fields (cone‐and‐plate, parallel plate and laminar flow in a tube). It was found that there was a rapid increase in the average agglomerate size followed by leveling off at long times resulting in an equilibrium particle size. This equilibrium particle size was found to be a strong function of the applied shear rate. It was further found that agglomerate data from the different flow fields superposed well, and, at least in the range of solid volume fractions considered, particle migration was negligible. This work provides a simple technique for quantifying demixing in laboratory experiments and applying the results to industrially relevant situations.
Experimental and numerical characterization of viscous flow and mixing in an impinging jet contactor
Authors: Unger David R. , Muzzio Fernando J. , Brodkey Robert S. 
Published: March 2009

AbstractThe laminar flow in an impinging jet contactor is examined as a first step toward the development of new technology for fast mixing of viscous fluids. The flow, velocity, and stretching fields in an impinging jet contactor are quantified for low Reynolds number flow using three‐dimensional numerical simulations and particle image velocimetry measurements. Computational and experimental velocity fields are in close agreement, as quantified by the velocity probability density functions. Two steady‐state flow regimes are found to exist: for jet Reynolds numbers (Rej) < 10, the jets do not impinge and the velocity field scales linearly with Reynolds number; for Rej > 10, the jets begin to impinge and recirculation regions form above and below the impingement point. The magnitude of the rate‐of‐strain tensor is calculated as a function of Rej. While areas of essentially zero stretching occupy most of the flow domain, very high rates of stretching occur at specific locations in the flow. The maximum and average rates of stretching in the contactor increase roughly linearly as a function of Reynolds number. Mixing simulations show that no mixing occurs for the steady flow in a symmetric‐jet contactor. However, mixing is improved substantially by a slight modification of the impinging jet geometry that disrupts geometric symmetry.
Experimental measurements and simulation of mixing and chemical reaction in a stirred tank
Authors: Zipp Robert P. , Patterson Gary K. 
Published: March 2009

AbstractEffects of mixing on the rate of second‐order chemical reactions have been studied by measuring the time‐average degree of conversion at enough points in a steady‐state, continuous‐flow stirred reactor to provide comparisons with numerical simulations of the same reactions using a standard Reynolds‐averaged turbulence simulation code with an added closure. The reactants were introduced in widely separated feed streams in order to provide a difficult test for the measurements and simulations. Concentration and segregation measurements were made with two fluorescence based methods ‐ one remote and one using a fiber optic probe. The rates of mixing and reaction were simulated using the Corrsin mixing term and the Spalding segregation production term with the Paired‐Interaction reaction closure term.
A study of an up‐ and a down‐pumping wide‐blade hydrofoil impeller: Part II. CFD analysis
Authors: Jaworski Zdzislaw , Dyster Kate N. , Mishra Ved P. , Nienow Alvin W. , Wyszynski Miroslaw L. 
Published: March 2009

AbstractTwo different ways of using CFD to determine the flow field produced by the complex, wide‐blade hydrofoil APV‐B2 impeller are presented. The use of the “sliding mesh” approach was not successful and the reasons are discussed. Details of the numerical solution of the momentum transfer equations are described for the case of an axially‐symmetrical jet model. The flow field for the single impeller pumping either upwards or downwards at 200 rpm was simulated using the structured Fluent code. Good agreement of CFD predictions with LDA velocity data was found, though the maximum local energy dissipation rate was 2 1/2 to 5 times lower than was estimated from the experiments. The power numbers predicted by CFD were slightly higher than those obtained experimentally. The flow fields for dual and triple impellers pumping upwards were also simulated and used to guide larger scale homogenisation experiments.