bluuebunny/crossref_metadata_2025 huggingface dataset:
Rorty on Science and Politics
Authors: Kremer Alexander
Published: March 2009

Rorty on Science and Politics

In my paper I will prove my overall thesis that Rorty consistently enforces his politically saturated liberal ironic standpoint in the fields of science and politics from his "Contingency" book (1989). As a neopragmatist thinker he gives priority to politics in the sense of a liberal democracy over everything else. Even philosophy as "cultural politics" serves this purpose. He did not want to create a detailed political philosophy, but the main motive of his philosophy is political. He is charged with complacency, relativism and misinterpreting traditional pragmatism, but I show that this is mistaken. Rorty offers "only" a non-systematic, but logical and permanently developed interpretation of our present world on the basis of knowledge he appropriated and improved by building bridges between pragmatism, analytic and continental philosophy. I will analyze briefly in the first part his neo-pragmatist thoughts on science in connection with his political views. In the second part I will interpret Rorty as a liberal ironist who regards almost everything as contingent, except democracy. He outlines a liberal utopia that means first of all a just society in a Rawlsian sense, but he also develops his idea further in a neo-pragmatic way.
Rorty's Neopragmatism and the Imperative of the Discourse of African Epistemology
Authors: Udefi Amaechi
Published: March 2009

Rorty's Neopragmatism and the Imperative of the Discourse of African Epistemology

Pragmatism, as a philosophical movement, was a dominant orientation in the Anglo-American philosophical circles in the late nineteenth century and early twentieth century. Pragmatism, as expressed by its classical advocates, namely, Charles Sanders Peirce, William James and John Dewey, emphasized the primacy of practice or action over speculative thought and a priori reasoning. The central thesis of pragmatism (though there exist other variants) is the belief that the meaning of an idea or a proposition lies in its "observable practical consequences", And as a theory of truth, it diverges from the correspondence and coherence theories which see truth in terms of correspondence of a proposition to facts and coherence of propositions to other propositions within the web respectively, but instead contends that "truth is to be found in the process of verification". In other words, pragmatists would emphasize the practical utility or "cash value", as it were, of knowledge and ideas as instruments for understanding reality. Neopragmatism is used to refer to some contemporary thinkers whose views incorporate in a significant way, though with minor differences bordering on methodology and conceptual analysis, the insights of the classical pragmatists. Our intention in this paper is to explore Rorty's neopragmatism, particularly his critique of analytic philosophy and then argue that his views have potential for the establishment of African epistemology as an emerging discourse within the African philosophical tradition.
Two Dogmas of Rorty's Pragmatism
Authors: Vuorio Timo
Published: March 2009

Two Dogmas of Rorty's Pragmatism

Here I discuss two controversial distinctions that have an essential role in Rorty's pragmatism: the distinction between descriptive and normative discourses, and the distinction between the private and public dimensions of human life. Neither of them is Rorty's novelty, but the way he stresses them is unique. The first is a central presupposition of his Philosophy and the Mirror of Nature (1979), while the other is the argumentative base of Contingency, Irony, and Solidarity (1989). I will argue that the distinctions provide metaphilosophical tools for Rorty's pragmatism, and that our stance towards the latter depends on the plausibility of them.
Baffle‐induced segregation in spouted beds
Authors: Rovero Giorgio
Published: March 2009

Segregation of solid materials, differing in density, was detected at the surface of the annulus of a spouted bed when a baffle, preventing mixing with solids from the fountain, was placed above an overflow pipe. Concentrations higher than 90% by volume in the light material could be obtained in the continuous discharge stream from a well mixed bed having an overall light‐solids concentration as low as 3%. The gas velocity in the annulus, exceeding the minimum fluidization velocity of the light component, was shown to be the mechanistic explanation of the phenomenon.
Role of vapor‐liquid equilibrium in evaluation of coal liquefaction kinetics
Authors: Gopal J. S. , Shah Y. T. , Carr N. L.
Published: March 2009

The role of vapor liquid equilibrium in the coal liquefaction process and its effect on the process kinetics were studied. Available experimental data were analyzed by inclusion of vapor‐liquid equilibrium in an existing model to study its effect on the kinetics. The analysis showed that due to liquid vaporization, a significant increase in the slurry residence time occurs. In the range of operating variables investigated, the actual slurry residence time was observed to be higher by a factor of 1.14 to 1.41.

Model simulations for some typical operating conditions (717‐737 K, 13.8‐20.7 MPa) showed the wt. fraction of liquid vaporized to be in the range of 0.1 to 0.3. This is seen to be in agreement with published data on the volatility of typical coal liquids. This study has shown that consideration of vapor‐liquid equilibrium in the kinetics and design of coal liquefaction process can be of importance, especially at high temperatures, where vaporization would be significant.
Fractionnement de deux bois tropicaux (eucalyptus et wapa) par traitement thermomécanique en phase aqueuse. Partie I: Conversion et profils de solubilisation
Authors: Carrasco F. , Chornet E. , Overend R. P. , Heitz M.
Published: March 2009

La conversion et les profils de solubilisation de deux bois tropicaux ont été étudiés par voie d'un traitement thermo‐mécanique en phase aqueuse. Une suspension de bois ayant une concentration en sol ides de 8% est préchauffée (cuisson à 135°C) et envoyée pneumatiquement à travers un capillaire à des vitesses comprises entre 50 et 115 m/s. A la sortie du capillaire, une détente soudaine (décompression flash) facilite la désagrégation du complexe hémicelluloses–lignine–cellulose. La séparation des hémicelluloses et de la lignine a été examinée en fonction de la sévérité thermique du traitement (150–230°C). Les résultats présentés permettent de conclure qu'un fractionnement sélectif de la lignine associée à la lamella composée (. mitoyenne plus la paroi primaire) et des hémicelluloses est possible pour les bois tropicaux considérés dans ce travail. Les conditions opératoires optimales sont discutées en fonction des observations expérimentales.
Low pressure drop gas distributors for packed distillation columns
Authors: Muir L. A. , Briens C. L.
Published: March 2009

Packed distillation columns require gas distributors which provide uniform vapor distribution with a low pressure drop. Gas velocity profiles were measured for various gas distributors in a scale model of the gas distribution chamber of a packed distillation column.

The most uniform gas distribution was obtained with two tangential inlets halfway up the distribution chamber and a deflector which induced a downward swirl to help collect any unvaporized liquid droplets. The insertion of a ring above the deflector further improved the vapor distribution.
Diffusional effects in wetproofed catalysts for isotopic exchange between hydrogen gas and water vapour
Authors: Suppiah S. , Chuang K. T. , Rolston J. H.
Published: March 2009

Deuterium transfer rates between water vapour and hydrogen gas have been obtained for platinized carbon powder (Pt‐C) and Teflon wetproofed platinized carbon films. The pore diffusional resistance in the catalyst films was assessed by calculating the effectiveness factor, ϵ, from a mathematical model for simultaneous diffusion and first order reversible reaction kinetics. Wetproofing the Pt‐C catalyst with Teflon increased the intrinsic rate of reaction, but the effectiveness factor decreased with increasing catalyst layer thickness. Pore size and surface area distributions and water vapour adsorption isotherms of the Pt‐C/Teflon catalyst films were similar to those of the Pt‐C itself. Since Teflon had negligibly small surface area and very large pores compared to the carbon support, wetproofing did not cause significant changes to the physical characteristics of the platinized carbon.
Co‐processing of alberta subbituminous coal and bitumen in a semi‐continuous hot charge‐discharge unit
Authors: Kovacik G. , Özüm B. , Oguztöureli M. N.
Published: March 2009

Liquefaction of an Alberta subbituminous coal (Highvale) with bitumen was studied using a semi‐continuous, two stage, hot charge‐discharge (HCD) unit. Experiments were performed using a CO/steam atmosphere in the first, and H2 atmosphere in the second stage. The second stage (hydrogenation) reactor input and output gas temperatures, compositions, reactor gas and liquid temperatures were measured during the reaction. In the numerical solutions of the mass and energy balance equations experimental data were used, and hydrogen consumption, heteroatom (O and S) removal, hydrocarbon gas production kinetic rate constants, and hydrogenation reaction enthalpy were determined.
Spouted bed hydrodynamics in a 0.91 m diameter vessel
Authors: Lim C. J. , Grace J. R.
Published: March 2009

Hydrodynamic measurements were obtained in a flat‐based half‐cylindrical column of diameter 0.91 m and inlet orifice diameters of 76 to 114 mm. Beds of 3.5 to 6.7 mm diameter particles with static depths of 0.53 to 1.83 m were spouted with air. In agreement with measurements by earlier workers in smaller columns, it was found necessary to operate with inlet orifice diameters less than about 30 times the mean particle diameter in order to be able to achieve stable spouting. Correlations for minimum spouting velocity developed on small vessels generally gave poor predictions for the large diameter vessel employed in this work and failed to predict the observed dependence of Ums on the static bed height. Substantial dead regions where particles were stagnant were observed in the lower outer portion of the vessel. Other aspects of behaviour studied, including spout diameters and shapes, fountain heights, pressure profiles and gas velocities in the annulus, were qualitatively similar to those in smaller columns, although equations developed for the smaller vessels did not always provide accurate predictions.
The deposition of haematite particles from flowing water
Authors: Williamson R. , Newson I. , Bott T. R.
Published: March 2009

Deposition of 0.2 μ haematite (α – Fe2O3) particles from suspension in turbulently flowing water, Reynolds Number = 11000, onto metal tube surfaces has been studied with particular reference to the effect of pH. Measurements on stainless steel showed trivial deposition outside the pH range 5 to 8. Within this range deposition rose sharply to a peak at pH = 6.2. This is similar to the findings of Kuo and Matijevic (1980) who studied haematite particle deposition onto a packed bed of stainless steel beads under laminar flow conditions. This shows that particle/surface interactions govern deposition in this system and that hydrodynamic and geometric factors are secondary.
Properties of cold lake bitumen saturated with pure gases and gas mixtures
Authors: Mehrotra Anil K. , Svrcek William Y.
Published: March 2009

This paper presents new data for the viscosity, density and gas solubility of Cold Lake bitumen saturated with light gases and gas mixtures over a temperature range of 15 to 103°C at up to 10 MPa pressure. Specifically, the gases whose effects on the bitumen properties were measured are N2, CH4, CO2 and C2H6, and two mixtures of CO2 and CH4. With CO2 and C2H6, experiments were also performed in the liquid‐liquid region, and the results of these experiments generally agree with the previously published predictions.

The viscosity of the gas‐free Cold Lake bitumen is comparable to that of a Marguerite Lake bitumen that was tested previously. Due to the large solubilities of C02 and C2H6, the reduction in gas‐saturated bitumen viscosity is quite dramatic. The density of the gas‐saturated bitumen decreases with increased amounts of the dissolved CH4 and C2H6 gases, but no such trends are evident for the N2 and CO2 gases. The results of the experiments with two binary gas mixtures (i.e., CO2 and CH4) indicate that the bitumen properties are affected largely by the major gas constituent.
Study of the transport disengaging height
Authors: Baron T. , Briens C. L. , Bergougnou M. A.
Published: March 2009

The trajectory of clusters ejected in the freeboard by gas bubbles bursting at the surface of fluidized beds is used to propose a new way to determine the transport disengaging height (TDH). As the effect of the drag force is negligible for the largest clusters, the maximum height they reach in the freeboard is directly proportional to the square of their ejection velocity. The maximum heights thus calculated are in good agreement with experimental TDH values from the literature. A procedure is given to compute the TDH from this simple expression.
Independent prediction of slip velocity and hold‐up in liquid/liquid extraction columns
Authors: Kumar Arun , Hartland Stanley
Published: March 2009

The correlation of slip velocity using a large bank of published data for pulsed perforated‐plate, Karr reciprocating‐plate, rotating disc and spray extraction columns is presented. Based on more than 3,700 data points with and without mass transfer, empirical equations not including hold‐up for each of the columns are suggested which reproduce the slip velocity data over a wide range of variables. Explicit correlations for hold‐up in both the loose and dense‐packed regions of operation in spray columns are also presented which do not involve slip velocity. The equations presented are more exact and simpler to use than previous empirical correlations; these often involve the characteristic velocity which is difficult to accurately predict.
Zncl2 catalyzed flash hydropyrolysis of +525°C pitch from cold lake bitumen
Authors: Pandey Raj N. , Ingard Eric , Ternan Marten
Published: March 2009

Flash hydropyrolysis experiments have been performed on the vacuum bottoms fraction of Cold Lake bitumen, using zinc chloride as a catalyst. Milligram size samples of vacuum bottoms resid were heated rapidly (120–400°C/s) by passing a large electric current through the reactor tube. The variables studied included temperature, heating rate, catalyst/pitch ratio, vapour phase residence time and pressure. Temperature and catalyst/pitch ratio caused major changes in yields. In contrast pressure had little effect. It was found that high conversions could be obtained at hydrogen pressures which are much lower than those normally used in catalytically hydrocracking residual oils.
Four‐lump kinetic model for fluid catalytic cracking process
Authors: Lee Liang‐Sun , Chen Yu‐Wen , Huang Tsung‐Nien , Pan Wen‐Yen
Published: March 2009

In the fluid catalytic cracking reactor heavy gas oil is cracked into more valuable lighter hydrocarbon products. The reactor input is a mixture of hydrocarbons which makes the reaction kinetics very complicated due to the involved reactions. In this paper, a four‐lump model is proposed to describe the process. This model is different from others mainly in that the deposition rate of coke on catalyst can be predicted from gas oil conversion and isolated from the C1–C4 gas yield. This is important since coke supplies heat required for endothermic reactions occurring in the reactor. By this model we can also conclude that the C1–C4 gas yield increases with increasing reactor temperature, while production of gasoline and coke decreases.
Reaction kinetics of gasification of black liquor char
Authors: Li J. , Van Heiningen A. R. P.
Published: March 2009

CO2 gasification of black liquor char, prepared from kraft spent pulping liquor is studied thermogravimetrically up to 775°C. The gasification rate is described by Langmuir‐Hinshelwood type kinetics and activation energy is similar to that found for alkali metal impregnated porous carbons. However the rate is about 20 times larger than that of coal char mixed with 10‐20% Na2 CO3. CO inhibition is relatively small and the rate is first order in carbon up to 80% conversion. The behavior is explained by a fine and three‐dimensional dispersion of sodium salts in the char. The rate is insensitive to pulping conditions over the range of industrial practice.
Modelling the transition to slug flow in horizontal conduit
Authors: Jepson W. P.
Published: March 2009

A physical model for the prediction of transition to slug flow is presented. The model assumes that the slug is formed as a result of a hydraulic jump which is sufficient to just touch the top wall of the conduit. This, together with a ‘breaking dam’ assumption at the rear of the slug, gives necessary and sufficient conditions for the formation of a stable slug. The minimum liquid film thickness ahead of the slug, degree of aeration within the slug and slug translational velocity are predicted. The predictions agree very well with those of previous workers and with experimental data.
Droplet size characteristics for insecticide and herbicide spray atomizers
Authors: Picot J. J. C. , Vliet M. W. Van , Payne N. J.
Published: March 2009

Rotary atomizers and hydraulic nozzles used in forestry spraying were extensively tested with laser light scattering, laser light imaging, and photographic methods in a specially designed wind tunnel. Data on droplet size distribution and cumulative volume fraction versus droplet size are given. Correlations for reduced volume median diameter (Dv,0.5/d0) and reduced span ((Dv.0.9 – Dv.0.1)/d0) presented. Accuracy of prediction is of the order of 20% for hydraulic nozzle volume median diameter. Accuracy of prediction for high‐speed rotating wire mesh atomizers is of the order of 35% for the volume median diameter. When these accuracies are inadequate, a specific test of the device in question is recommended.
Separation of kinetics and mass‐transfer in a batch alkoxylation reaction
Authors: Hall C. A. , Agrawal P. K.
Published: March 2009

The quantitative aspects of the role of interfacial mass‐transfer and reaction kinetics in ethoxylation of lauryl alcohol were examined in a batch recirculation reactor. The liquid droplets falling through a gas column were obtained by utilizing a recirculation loop and a set of spray nozzles. The CO2/NaOH reaction was employed to characterize the interfacial area. The alkoxylation reaction was studied at temperatures between 124°C and 171°C, at catalyst levels between 0.09 and 0.50 weight percent and at ethylene oxide partial pressures between 68 kPa and 204 kPa.

A model was developed which permits the prediction of reactor performance at various operating conditions. The mass‐transfer during free fall dominates the interfacial mass‐transfer and the contributions during the drop formation and coalescence stages are small. The rate of ethylene oxide (EO) addition to lauryl alcohol was constant during the batch run, indicating similar activity for the unreacted lauryl alcohol and the lauryl alcohol ethoxylated to varying extents. The rate of ethoxylation is first‐order in both catalyst and ethylene oxide concentrations. The liquid‐phase reaction kinetics and interfacial mass‐transfer occur in series, with kinetics dominating the overall ethoxylation rate. As expected, an increasing role of mass transfer is observed at higher temperatures, and/or higher catalyst concentrations where the kinetic rate becomes significantly high. The intrinsic activation energy for the ethoxylation of lauryl alcohol is 55.2 kJ/mole.
A simplified approach to the operation of a batch crystallizer
Authors: Rohani S. , Bourne J. R.
Published: March 2009

A general model for a seeded cooling batch crystallizer based on first principles is developed, incorporating either size‐dependent or size‐independent growth rates. A simple approach is proposed to obtain temperature‐time trajectories at constant supersaturation or nucleation rate, without resorting to optimization techniques. Cooling curves at constant supersaturation, which lead to a substantial improvement (a smaller coefficient of variation and a larger mean size) of the terminal crystal size distribution, can be determined even in the absence of precise nucleation and growth kinetics, whereas properties related to the crystal size distribution are sensitive to such kinetics. Experimental results for the potassium sulfate‐water system, potash alum‐water system, and hexamethylenetetramine in ethanol, methanol, and 2‐propanol/water are predicted reasonably well by the model. Extension to any type of batch crystallization with super‐saturation induced by means other than cooling, such as reactive precipitation and salting out, is briefly discussed.
The prediction of transport parameters in filamentous fermentation broths based on results obtained in pseudoplastic polymer solutions
Authors: Allen D. Grant , Robinson Campbell W.
Published: March 2009

Transport phenomena studies on single phase “model” fluids are of limited value in biochemical engineering if they cannot be translated to the heterogeneous systems encountered in real fermentation processes. In this paper we discuss the utility of polymer solutions as models of filamentous fermentation broths for evaluation of: pipeline friction factors and impeller power numbers (turbine and helical ribbon). To a first approximation, polymer solutions can serve as suitable models for the prediction of laminar flow pressure drop in pipelines and turbulent power consumption in stirred tanks. However, results obtained on polymer solutions do not directly apply to filamentous fermentation broths for predictions of laminar flow impeller power consumption and the transition point for turbulent flow in stirred tanks. These discrepancies are believed to result from the existence of a time dependent yield stress in filamentous fermentation broths.
Kinetics of, free radical modification of polyolefins in extruders – chain scission, crosslinking and grafting
Authors: Hamielec A. E. , Gloor P. E. , Zhu S.
Published: March 2009

Free radical reactions, carried out in polymer melts, have become a popular method of chemically modifying polyolefins. The elementary free‐radical reactions which are relevant in the chemical modification of polyolefins at high temperatures in extruders, such as chain transfer to polymer via primary and polymer radicals, β‐scission, double bond addition and bimolecular termination, affect chain scission, long chain branching, crosslinking and grafting. This brief review will discuss some of the work focused on the kinetics and mathematical modelling of these reactions.
Hydrodynamics of disturbed flow and erosion—corrosion. Part I — Single‐phase flow study
Authors: Nešiĉ S. , Postlethwaite J.
Published: March 2009

Numerical simulations of turbulent flow have been used to determine the flow structure in a sudden pipe expansion, in order to explain the effects of disturbed flow on mass transfer controlled erosion–corrosion. Previously determined rates of mass transfer through the liquid boundary layer have been directly related to the predicted levels of near‐wall turbulence. When rust films are present, the turbulent fluctuations affect both the mass transfer through the boundary layer and the removal of the film. The determining resistance to mass transfer, under the conditions examined, was that of the rust film.
Mechanism, onset and intensity of surface aeration in geometrically‐similar, sparged, agitated vessels
Authors: Veljković V. B. , Bicok K. M. , Simonović D. M.
Published: March 2009

Under sparged conditions surface aeration occurs by two mechanisms: first, the absorption of gas at the free surface and then its desorption at the gas bubbles‐liquid interfaces, and second, mechanical suction through the free surface; the latter is believed to occur via vortices formed on the free surface due to impeller action. The onset of gas entrainment is defined through the characteristic impeller speed above which mechanical suction rapidly increases. Gas entrainment intensity is correlated by the specific power input and the superficial sparge velocity and generally increases with increasing impeller speed and decreasing sparge gas flow rate.
Dispersion and slip effects in hydraulic hoisting of solids
Authors: Evans J. , Shook C. A.
Published: March 2009

Concentration changes which occur in cyclical hydraulic hoisting operations can be modelled with a form of the convection‐diffusion equation. In order to solve this equation it is necessary to specify the axial dispersion coefficient and the effective slip of the particles relative to the mean velocity. The effective slip depends upon drag and particle migration effects.

Experimental observations of these concentration changes are interpreted with numerical solutions of the appropriate equation. Fine particles develop a near‐Gaussian concentration distribution while coarse particles produce a saw‐tooth pulse. Axial dispersion coefficients are similar to those observed with solutes in turbulent slurry flows and slip velocities are shown to be concentration dependent.
Heat transfer and gas holdup studies in a bubble column: Air‐water‐sand system
Authors: Saxena S. C. , Rao N. S. , Saxena A. C.
Published: March 2009

Air‐holdup and heat transfer coefficient data are reported for the air‐water and air‐water‐sand system as a function of air velocity in the temperature range 297‐343 K as measured in a 0.305 m diameter bubble column operating in semi‐batch mode and equipped with either a five‐ or seven‐tube bundle. A 65 μm average size sand powder is used at concentrations of 5 and 10 mass percent in the slurry. Available correlations of gas holdup and heat transfer coefficients are examined on the basis of these data. These are found inappropriate and inadequate for representing these experimental data. Gas holdup data are well represented by an approach based on Nicklin's (1962) work, and heat transfer data are adequately represented by a simple semi‐empirical expression. Accurate experimental data on additional systems are needed to develop a reliable heat transfer theory particularly for process representation at temperatures higher than ambient.
The internally circulating fluidized bed (ICFB): A novel solution to gas bypassing in spouted beds
Authors: Milne Bruce J. , Berruti Franco , Behie Leo A. , De Bruijn Theo J. W.
Published: March 2009

The bypassing of a portion of the inlet spout gas to the annular region of spouted and spout‐fluid beds can have a critical effect on processes requiring accurate control of the spout gas residence time even when a draft tube is utilized. A modification to the spout‐fluid bed with draft tube called the Internally Circulating Fluidized Bed or ICFB is proposed which eliminates this bypassing problem. Experiments were conducted on a cold 20 cm diameter semi‐cylindrical unit to define the operational characteristics of the ICFB with particular emphasis on the gas and solids flow behavior. The solids and gas flow rates in the unit were successfully related by a published correlation which was developed for the cocurrent flow of gases and solids through orifices.
Drying characteristics in a jet‐spouted bed dryer
Authors: Markowski A. S.
Published: March 2009

A conical jet‐spouted bed dryer with inert bodies was used for drying of animal blood plasma. The effects of the operating conditions on the product properties, final moisture content and throughput of the dryer were investigated. A drying rate model using the conventional rate equation, where the overall effective driving force is based on the surface temperature calculated from the unsteady‐state heat transfer Fourier equation, was proposed. Satisfactory agreement between calculated and experimental results was obtained.
Fours rotatifs: Modèle dynamique du mouvement du lit
Authors: Perron J. , Bui R. T.
Published: March 2009

The motions of the granular bed inside a rotary furnace are governed by complex dynamics consisting of two modes. The axial velocity of the active layer on top of the bed represents the fast mode, while the overall velocity in the bed follows a slower mode. The proposed nonlinear model focuses on the dynamics of the slow mode. The difficulties of an analytic solution are avoided by a numerical method that employs several correlations. The model can reproduce the experimental transient responses. It is concluded that rotary furnaces respond better to small amplitude excitations than to large ones; consequently, closed‐loop control is well suited for this type of furnace.
Bubble size distribution in a flotation column
Authors: Biswal S. K. , Reddy P. S. R. , Bhaumik S. K.
Published: March 2009

The bubbles that were generated in a flotation column were measured. The bubble size distributions were obtained both for air‐water and air‐water‐coal systems. The size distribution pattern was fitted to different equations. It was found that the bubble size distribution in both the flotation and cleaning zones follows the Rosin‐Rommler equation used to describe the particle size distribution in crushing. This study indicates that bubbles in the cleaning zone are always larger than those of the flotation zone and finer bubbles are generated when a mixture of frothers is used instead of individual frothers.
Drying paper by impinging jets of superheated steam. Part 1: Constant drying rate in superheated steam
Authors: Bond J. F. , Mujumdar A. S. , van Heiningen A. R. P. , Douglas W. J. M.
Published: March 2009

Over a wide range of operating conditions, the drying of paper by impinging jets of superheated steam proceeds by a constant rate period followed by a falling rate period. The constant drying rate, investigated here in the jet temperature range 150 ≤ Tj/ ≤ 465°C and over jet Reynolds numbers of 1000 ≤ Rej ≤ 12000, is predicted within + 12% by a heat transfer expression using Martin's (1977) correlation for the heat transfer coefficient corrected for mass transfer by the Couette flow approximation factor, and a property ratio to account for the large temperature difference between the jet and the paper.
Gas evolution from the aquathermolysis of heavy oils
Authors: Belgrave J. D. M. , Moore R. G. , Ursenbach M. G.
Published: March 2009

Aquathermolysis experiments were performed on core samples taken from three large bitumen and heavy oil deposits found in Alberta, to investigate gas evolution over the temperature range 360 to 420°C. Experiments conducted on Athabasca included runs with an initially pre‐oxidized oil sample and runs with a change in core mineralogy. Pre‐oxidizing the oil was found to substantially increase the amount of carbon monoxide and molecular hydrogen generated. Core mineralogy played an important role in the generation of carbon dioxide, and the amount of hydrogen sulphide produced was dependent on oil composition, mineralogy and time. Although substantial amounts of gaseous products are produced by simple thermolysis reactions (i.e., without water present), the main thermal recovery methods, steam injection and in‐situ combustion, bring the oil phase and its host rock into direct contact with water. As water has been shown to take part in thermal cracking reactions, these experiments provide usful data for the estimation of produced gas composition during thermal recovery projects.
Effets de differents parametres sur les vitesses de transition de la fluidisation en regime turbulent
Authors: Chehbouni A. , Chaouki J. , Guy C. , Klvana Et D.
Published: March 2009

Une grande controverse existe dans la littérature concemant les effets de différentes variables sur les vitesses de transition de la fluidisation turbulente. A la lumière des résultats de la littérature, quatre paramètres ont été choisis: le diamètre de la colonne, le nombre d'Archimède, la hauteur initiale du lit et la distribution de diamètre des particules. Pour caractériser l'effet de ces quatre paramètres hydrodynamiques sur la vitesse de début du régime turbulent Uc et sur la vitesse de transport Utr, nous avons réalisé des expériences selon un plan expérimental de type Plackett‐Burman à huit essais pour Uc et Utr. Les facteurs et leurs niveaux de variation sont: (a) diamètre de la colonne (82 vs 200 mm), (b) particules (FCC vs sable), (d) hauteur statique du lit (300 vs 450 mm) et (g) distribution des particules (étroite vs large). Pour déterminer expérimentalement ces deux vitesses de transition, nous avons utilisé un capteur de pression différentiel et une sonde à capacitance. Les résultats expérimentaux et l'analyse statistique montrent que le diamètre de la colonne est le facteur le plus important (61% de variabilité pour Uc et 51% pour Utr). Les propriétés du solide (ρp, dp) viennent en deuxième lieu (35% de variabilité pour Uc et 47% pour Utr). L'effet de la hauteur statique est très faible et la distribution des particules n'a pratiquement pas d'effet sur les deux vitesses. Les résultats montrent aussi qu'il n'y a pas d'interactions entre ces paramètres. Enfin, nous avons proposé deux corrélations pour prédire Uc et Utr qui font intervenir le diamètre du réacteur.
Algebraic multigrid, mixed‐order interpolation, and incompressible fluid flow
Authors: Webster R.
Published: March 2009

This paper presents the results of numerical experiments on the use of equal‐order and mixed‐order interpolations in algebraic multigrid (AMG) solvers for the fully coupled equations of incompressible fluid flow. Several standard test problems are addressed for Reynolds numbers spanning the laminar range. The range of unstructured meshes spans over two orders of problem size (over one order of mesh bandwidth). Deficiencies in performance are identified for AMG based on equal‐order interpolations (both zero‐order and first‐order). They take the form of poor, fragile, mesh‐dependent convergence rates. The evidence suggests that a degraded representation of the inter‐field coupling in the coarse‐grid approximation is the cause. Mixed‐order interpolation (first‐order for the vectors, zero‐order for the scalars) is shown to address these deficiencies. Convergence is then robust, independent of the number of coarse grids and (almost) of the mesh bandwidth. The AMG algorithms used are reviewed. Copyright © 2009 John Wiley & Sons, Ltd.
Embryonic Stem Cells and Mammary Luminal Progenitors Directly Sense and Respond to Microbial Products
Authors: Lee Sung-Hyung , Hong Bangxing , Sharabi Andrew , Huang Xue F. , Chen Si-Yi
Published: March 2009

Stem cells are normally maintained in a quiescent state and proliferate only under certain conditions; however, little is known about the biological stimuli that initiate the proliferation and differentiation of stem cells. In this study, we found that functional Toll-like receptors (TLRs) are expressed on mouse embryonic stem (ES) cells and that TLR ligands stimulate ES cell proliferation and promote their hematopoietic differentiation. TLR ligands activate TLR-mediated signaling pathways, leading to the altered expression of numerous genes in ES cells. Moreover, TLR ligands efficiently stimulate the proliferation and expansion of adult stem cells and progenitors of nonhematopoietic tissues, such as mammary glands and intestine as well. We further found that mammary luminal progenitor cells (Lin−CD29+CD61+) express TLR4-MD2 complex and actively proliferate, resulting in the enhanced growth of mammospheres in response to TLR ligands. Thus, mouse ES cells and adult tissue-specific stem cells/progenitors directly sense and respond to microbial products, which function as a class of foreign, but biological stimuli for stem cell/progenitor proliferation. This finding expands the biological role of TLRs and has implications in understanding stem cell biology, tissue repair/homeostasis, and the role of infection and inflammation in malignant transformation.

Disclosure of potential conflicts of interest is found at the end of this article.
Commentary on “A roadmap for the prevention of dementia II. Leon Thal Symposium 2008.” Recruitment of participants for Alzheimer's disease clinical trials: The role of trust in caregivers, clinical researchers, regulatory authorities, and industry sponsors
Authors: Snyder Peter J. , Papp Kathryn V. , Bartkowiak Jennifer , Jackson Colleen E. , Doody Rachelle S.
Published: March 2009

A major barrier to progress in Alzheimer's disease treatment research is the increasingly difficult task of recruiting elderly participants into clinical trials. We conducted an anonymous online survey of 676 adults (average age, 50 years) to examine perceived trust in different components of our healthcare‐delivery and clinical‐research systems, as well as willingness to participate in clinical trials. Respondents indicated the greatest amount of trust in family members, followed by family physicians. Only 3% of respondents “completely” trusted clinical researchers, whereas 62% of respondents trusted them “somewhat” to care for them during the course of a clinical trial. Trust in clinical researchers was modestly negatively correlated with income (r = −0.165, P < .001), but was not significantly related to sex, race, or education. Respondents indicated the least amount of trust in industry sponsors, followed by regulatory authorities.
Evaluation of therapeutic effects on rectal varices using percutaneous color Doppler ultrasonography
Authors: Sato Takahiro , Yamazaki Katsu , Toyota Jouji , Karino Yoshiyasu , Ohmura Takumi , Akaike Jun
Published: March 2009

Aim:  We report the usefulness of percutaneous color Doppler ultrasonography (CDU) for evaluating therapeutic effects on rectal varices.

Methods:  Ultrasonographic examination and color flow imaging were performed using a color Doppler unit (Aplio 50 or XV, Toshiba, Tokyo, Japan) with a 3.5 MHz convex probe. We performed endoscopic injection sclerotherapy (EIS) for rectal varices in seven patients and partial splenic arterial embolization (PSE) for hypersplenism in four. We examined color flow images and measured the velocity of blood flow in rectal varices using fast‐Fourier transform analysis by CDU in all eleven patients, before and after treatments.

Results:  Rectal varices were detected by Doppler color flow imaging in all eleven patients before treatments. Blood flowvelocity in the rectal varices ranged from 5.7–11.6 cm/s (mean 8.6 cm/s). Rectal varices were observed in all patients by colonoscopy; enlarged, tortuous large varices with red color sign in nine and enlarged, tortuous large varices without red color in two. Seven days after EIS or PSE, CDU showed an extreme decrease in blood flow in all eleven rectal varices, compared to values before EIS or PSE.

Conclusions:  CDU can be performed repeatedly and is useful for evaluating the therapeutic effects of treatments for rectal varices.
Therapeutic benefits of partial splenic embolization for thrombocytopenia in hepatocellular carcinoma patients treated with radiofrequency ablation
Authors: Hidaka Hisashi , Kokubu Shigehiro , Nakazawa Takahide , Minamino Tsutomu , Takada Juichi , Tanaka Yoshiaki , Okuwaki Yusuke , Watanabe Masaaki , Shibuya Akitaka , Saigenji Katsunori
Published: March 2009

Aim:  Partial splenic embolization (PSE) is a non‐surgical procedure developed to treat hypersplenism. The purpose of this study is to evaluate therapeutic benefits of PSE with follow‐up radiofrequency ablation (RFA) treatment in hepatocellular carcinoma (HCC) patients with thrombocytopenia.

Methods:  Between September 1999 and January 2007, a total of 20 patients with HCC who had a few lesions, each 3 cm or less in diameter, and liver function of Child‐Pugh class A or B were enrolled into our study. The patients were diagnosed with marked thrombocytopenia (<50 × 103/mm3), or mild thrombocytopenia (<80 × 103/mm3) with decreased prothrombin activity. They were treated once or twice with PSE. RFA was given as a follow‐up treatment 2 weeks after final PSE. The primary endpoint was a platelet‐count increase and improvement of prothrombin activity, and the secondary endpoint was the initiation of RFA.

Results:  PSE was performed successfully in 19 patients (95%). Two weeks after final PSE, platelet counts increased significantly (38 ± 14 × 103/mm3 vs. 97 ± 43 × 103/mm3; P < 0.0001), and prothrombin activity improved significantly (59.3 ± 19.8% vs. 65.2 ± 17.9%; P < 0.0001). No patients had major complications during the PSE procedure. The secondary endpoint was achieved in 18 of 19 patients (94.7%). The mean overall survival was 2257 days (95% confidence interval; range, 1659−2855 days). The Kaplan‐Meier cumulative survival rate was estimated to be 61.9% at 5 years.

Conclusions:  PSE is a safe and effective treatment for thrombocytopenia and has adjuvant therapeutic benefits for the therapy of HCC.
Gene Transfer into Mammalian Cells Using a Self-Deleting Avian Leukemia and Sarcoma Virus-Based Vector
Authors: Torne-Celer Caroline , Moreau Karen , Faure Claudine , Verdier Gérard , Ronfort Corinne
Published: March 2009

Objectives: We have previously described an avian leukemia and sarcoma virus-based vector containing an additional att sequence in an internal position that is capable of self-deleting most of its 5′ viral sequences during one cycle of replication in avian cells [Virus Res 2008;135:72–82; Arch Virol 2008;153:2233–2243]. Herein, our aim was to test the infectivity and self-deleting properties of this avian retroviral vector in human cells. Methods: Human Hela cells transiently expressing the cellular receptor for avian leukemia and sarcoma viruses (tva) were infected with the avian vector. Molecular analyses of thirteen clones were performed. Results: Data showed that more than 77% of proviruses had lost the 5′ part of their genome including the selectable gene. At least 61% of these proviruses were flanked on the left by the additional att sequence and on the right by the LTR. None of the thirteen proviruses was able to express a full-length genomic RNA. Conclusion: This study demonstrates that the self-deleting properties of the avian vector in avian cells may be also applicable to human cells.
Towards Fibroid Gene Therapy: Adenovirus-Mediated Delivery of Herpes Simplex Virus 1 Thymidine Kinase Gene/Ganciclovir Shrinks Uterine Leiomyoma in the Eker Rat Model
Authors: Hassan Memy , Zhang Dong , Salama Salama , Hamada Farid , Arafa Hossam , Fouad Hala , Walker Cheryl , Al-Hendy Ayman
Published: March 2009

Background/Aims: The objective of this study was to assess in vivo gene therapy of uterine leiomyomas in the Eker rat model using adenovirus (Ad)-mediated delivery of herpes simplex virus 1 thymidine kinase gene (HSV1TK) followed by ganciclovir (GCV) treatment. Methods: We randomized 27 female Eker rats with MRI-confirmed uterine leiomyomas to a single treatment with direct intra-tumor injection of Ad-HSV1TK/GCV, Ad-LacZ/GCV, or medium alone. Samples were collected from tumors, other body organs, and blood at 10, 20, and 30 days after treatment to assess the safety and efficacy of the treatment. Results: Ad-HSV1TK/GCV treatment significantly decreased uterine fibroid volume by 75 ± 16, 58.7 ± 6.3, and 67.5 ± 27.5%, of the pretreatment volume at days 10, 20, and 30, respectively. Ad-HSV1TK/GCV increased caspase-3 activity, Bax expression, and TUNEL apoptosis marker, and it decreased cyclin D1, PCNA, Bcl2, and PARP protein expressions. Ad transfection induced local CD4+ and CD8+ infiltration and serum anti-Ad antibodies. Additionally, Ad transfection was tumor-localized and safe to non-target tissues. Conclusion: These studies demonstrate a marked efficiency and high safety for the Ad-HSV1TK/GCV therapeutic approach in the context of Eker rat uterine leiomyomas and provide essential preclinical data for the development of Ad-HSV1TK/GCV gene therapy for uterine fibroids.
High-Volume Hemofiltration in Sepsis and SIRS: Current Concepts and Future Prospects
Authors: Honore Patrick M. , Joannes-Boyau Olivier , Boer Willem , Collin Vincent
Published: March 2009

In recent years, a number of techniques have been studied and developed in the field of renal replacement therapy in the septic patient. Manipulation of ultrafiltrate dose, membrane porosity, mode of clearance, and combinations of techniques have yielded promising findings. However, at present, conclusive evidence based on well-designed, randomized controlled trials remains scarce, limiting the practical implementation of many techniques in daily practice outside the context of a study. From the few well-designed and documented studies that we have so far, it is safe to say that optimalization of delivered dose in renal replacement therapy has a proven positive effect. An ultrafiltration rate between 35 and 45 ml/kg/h, with adjustment for predilution and down time, can be recommended for the septic patient until other data are available. The results of further dose outcome studies with higher ultrafiltration rates will likely be the stepping stone to further improvements in daily clinical practice.
Monocyte and Neutrophil Chemotactic Activity at the Site of Interstitial Inflammation in Patients on High-Flux Hemodialysis or Hemodiafiltration
Authors: Olsson Jenny , Paulsson Josefin , Dadfar Elham , Lundahl Joachim , Moshfegh Ali , Jacobson Stefan H.
Published: March 2009

Background/Aims: We have observed a difference between patients on low-flux hemodialysis (HD) or peritoneal dialysis and patients on hemodiafiltration (HDF) or high-flux HD in the capacity of transmigrated leukocytes to mobilize CD11b in response to inflammatory stimuli compared with healthy subjects. This could be due to different interstitial chemokine concentrations. Methods: We measured concentrations of circulating and interstitial macrophage inflammatory protein-1α (MIP-1α), matrix metalloproteinase-9 (MMP-9)/neutrophil gelatinase-associated lipocalin (NGAL), monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) in 10 patients on HDF or high-flux HD and 11 healthy subjects by using immunoassay. Results: The interstitial concentrations of MIP-1α, MMP-9/NGAL and IL-8 were similar in patients and healthy subjects, while the corresponding concentration of MCP-1 was significantly higher in patients on HDF or high-flux HD as compared with healthy subjects (p < 0.01). Conclusion: We suggest that an equal or higher concentration of chemokines in the interstitium in patients with HDF or high-flux HD might be one mechanism responsible for the preserved function of transmigrated leukocytes.