Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1990-1994  (835)
  • 1991  (835)
  • Chemical Engineering  (643)
  • Genetics  (192)
  • 101
    Electronic Resource
    Electronic Resource
    Plasma deposition and etching of diamond-like carbon films (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 367-376 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Diamond-like carbon films have been deposited from ternary mixtures of butadiene, hydrogen and argon in a parallel plate plasma reactor at constant pressure and power. These films have been etched in O2 and CF4/O2 plasma discharges. A new linear relationship between the composition of the deposition gas mixture and a dimensionless number (EN) defined in terms of etch and deposition rates and the bias voltage during deposition has been derived. EN is a function of the ion flux during deposition. Electron-impact ionization processes are considered for relating the ion flux to the feed gas composition and ionization potentials. The etch and deposition rate data follow this linear relationship very well. The proportionality constant in this linear relationship varies with composition for CF4/O2 etching data. Film hardness and failure modes on silicon and glass substrates are also described.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370307
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 102
    Electronic Resource
    Electronic Resource
    Concentration gradients in supersaturated solutions: A thermodynamic analysis (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 490-498 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The development of a concentration gradient along the vertical axis of a column of quiescent solution is explained within the framework of nonequilibrium thermodynamics. The formulae derived enabled us to determine explicitly the concentration difference between two vertical levels in a liquid column and specific conditions under which the concentration profile is at equilibrium. The concept of solute cluster formation in a supersaturated solution is consistent with the presented theory although the theory itself does not provide any direct or indirect proof of the occurrence of clustering.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370403
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 103
    Electronic Resource
    Electronic Resource
    An analytic model of direct-contact heat transfer in spray-column evaporators (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 539-546 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The heat transfer to, and the resultant evaporation of, drops of a volatile liquid sprayed upward in an immiscible liquid flowing down in a vertical column are analyzed to enable calculation of the volumetric heat transfer coefficient in the column. For this analysis, a model is contrived that assumes no nucleation delay in initially monodispersed drops and a heat transfer to each of the drops, with simultaneous evaporation, that can be approximated by an empirical correlation for heat transfer to an isolated drop evaporating in a quiescent, sufficiently extended medium. The expression obtained for the volumetric heat transfer coefficient is used to predict its values under some particular column operating conditions, which are then compared with relevant experimental data found in the literature.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370407
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 104
    Electronic Resource
    Electronic Resource
    Separation of azeotropic organic liquid mixtures by pervaporation (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 581-588 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: We have shown that ionomeric membranes of perfluorosulfonic acid (PFSA) polymer allow selective pervaporation of polar organic compounds from their azeotropic mixtures with less polar compounds. A composite membrane of a thin PFSA polymer film, cast on a porous Teflon support, provided desirable permeant fluxes with good selectivity. Model binary azeotropes, composed of alcohols and hydrocarbons, were separated with total pervaporation fluxes of up to 9.5 kg/h·m2 using a stirred membrane permeation cell, the product side of which was exposed to vacuum. Fluxes increased with increasing alcohol content of the feed and with temperature. But the selectivity of the more permeating component remained reasonably constant around the azeotropic point and also over the range of temperature used in the study (25-55°C). Total pervaporation fluxes depended little on downstream pressure up to 6.66 kPa (50 torr). These separation data were explained by a mathematical model based on a solution-diffusion mechanism.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370411
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 105
    Electronic Resource
    Electronic Resource
    Molecular thermodynamics of solute-polymer-supercritical fluid systems (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 607-616 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The distribution coefficients of the solutes (toluene, naphthalene, and phenanthrene) are reported at infinite dilution between silicone rubber and supercriticalfluid carbon dioxide. A new technique is described in which a thin film of polymer is coated and cross-linked onto silica, and the distribution coefficient is measured rapidly by elution supercritical-fluid chromatography. Because CO2 significantly enhances the solute's volatility and its diffusion coefficient in the polymer, it is possible to study solute-polymer interactions at room temperature for nonvolatile compounds which would be difficult to study by conventional techniques such as gas chromatography. These infinite dilution data are used to determine solutepolymer interaction parameters to calculate phase diagrams over a wide concentration range. The residual, combinatorial, and cross-link contributions to the solute activity coefficient in the polymer are discussed as a function of concentration. In addition, pronounced pressure and temperature effects are described in terms of experimentally measured solute partial molar volumes (to - 14 L/mol) and partial molar enthalpies (to - 850 kJ/mol) in the fluid phase.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370414
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 106
    Electronic Resource
    Electronic Resource
    Masthead (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991) 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370501
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 107
    Electronic Resource
    Electronic Resource
    Nonlinear wave theory for dynamics of binary distillation columns (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 705-723 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A major difficulty in control of distillation columns stems from their nonlinear behavior, especially of columns producing high-purity products. Based on a previous development that adapted fixed-bed theories to simple countercurrent processes, this study has established a nonlinear wave theory for the nonlinear and distributed dynamics of binary distillation columns by including the effects of reflux, reboil, and combination of sections. This theory clearly elucidates the intriguing dynamic behavior of distillation columns such as high steady-state gains, large response lags, strong dependence of dynamics on the magnitudes and directions of disturbances, and asymmetric dynamics of the transitions between two steady states. It also underlines the inadequacy of conventional linearized models for high-purity columns. With fairly simple mathematics, this nonlinear wave approach may be useful for model development, control system design, dual-composition control, and feedforward control.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370509
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 108
    Electronic Resource
    Electronic Resource
    Extent of reaction in open systems with multiple heterogeneous reactions (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 687-693 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The familiar batch concept of extent of reaction is reexamined for systems of reactions occurring in open systems. Because species concentrations change as a result of transport processes as well as reactions in open systems, the extent of reaction has been less useful in practice in these applications. It is shown that by defining the extent of the equivalent batch reaction and a second contribution to the extent of reaction due to the transport processes, it is possible to treat the description of the dynamics of flow through porous media accompanied by many chemical reactions in a uniform, concise manner. This approach tends to isolate the reaction terms among themselves and away from the model partial differential equations, thereby enabling treatment of large problems involving both equilibrium and kinetically controlled reactions. Implications on the number of coupled partial differential equations necessary to be solved and on numerical algorithms for solving such problems are discussed. Examples provided illustrate the theory applied to solute transport in groundwater flow.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370507
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 109
    Electronic Resource
    Electronic Resource
    Rapid carbothermal reduction of boron oxide in a graphite transport reactor (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 759-768 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Uniform submicron crystals of B4C, boron-enriched boron carbide, and B4C/TiB2 composite powders have been synthesized continuously by rapid carbothermal reduction at approximately 2,200 K in a 0.14 m ID × 1.68 m long pilot-scale graphite transport reactor. A unique reactor design allowed for continuous feeding of a meltable boron oxide containing precursor, rapid heating rates that completed the carbothermal reduction reaction in seconds, and an expanded cooling that allowed for the precipitation in space of volatile excess boron oxides. Powder morphology resembled that of powder synthesized by laser pyrolysis of gaseous reactants. Rapid heating rates and minimized reaction times at high temperatures promoted nucleation with limited crystal growth. Dense parts fabricated from these powders had fine grains and extreme hardness.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370513
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 110
    Electronic Resource
    Electronic Resource
    Masthead (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991) 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370601
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 111
    Electronic Resource
    Electronic Resource
    Kinetics of deactivation of bifunctional Pt/Al2O3—Cl catalysts by coking (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 845-854 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The catalytic activity, product selectivity, and coke deposition were studied during methylcyclopentane (MCP) reforming on bifunctional Pt/Al2O3—Cl reforming catalysts with different metal loadings, but constant metal dispersion as well as constant Cl loading. Surprisingly, the overall conversion of MCP was found to decrease as the metal content of the catalyst increased. Analysis of the coke by temperature programmed oxidation (TPO) revealed two distinct peaks, one associated with coke on the metallic function and the other associated with coke on the acidic function. The change of activity of the metal and acid functions with time was monitored by following the rates of hydrogenolysis and hydrocracking, respectively. A mechanistically-based dual-site model for the kinetics of coke formation and the resulting deactivation was developed. The model successfully correlates the experimental data and is an improvement over existing models, since it explicitly accounts for the deactivation of both the metal and the acid functions.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370607
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 112
    Electronic Resource
    Electronic Resource
    Schedule optimization with simultaneous lot sizing in chemical process plants (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 886-896 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Operational problems are of increasing importance as the process industries turn to the batch manufacture of high-value specialty products. A method is presented to minimize stockout for multiunit plants where customer orders may constitute nonintegral batch multiples. Product- and unit-dependent processing times and batch sizes, sequence-dependent changeover times, and product-to-unit assignment constraints are modeled for nonidentical parallel processes. Arbitrary initial conditions are also modeled. The algorithm determines the number of production runs of each product, run length (lot sizing), the assignment of run to units, and run sequence on each unit.Scheduling with simultaneous lot sizing has not previously been addressed in the literature. The evolutionary method presented here obtains near-optimal (and often globally optimal) solutions on industrial-sized test problems. These results are significant since near-optimal scheduling of many industrial process plants now becomes possible, although problems of this complexity are intractable using exact methods.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370611
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 113
    Electronic Resource
    Electronic Resource
    Model for spherical cavity radii and potential functions of sorbates in zeolites (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 923-930 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A spherical pore model for calculating the zeolite cavity radius and the potential energy of interactions of noble gases (Ar, Kr, Xe) is presented. The model utilizes the gas adsorption isotherm and equates the free energy change upon adsorption to the potential energy of interaction of the gas molecules with the zeolite cavity. The results obtained for the cavity radius using Ar, Kr, and Xe adsorption isotherms are in excellent agreement with those of the cavity radius for 5A, 13X, and Y zeolites obtained from crystallographic data. Also, the average potential energies of interaction of these gases with the surface atoms of the zeolite cavities, calculated from the isotherms and the spherical pore model, compare reasonably well with the internal energies determined from the experimental heats of adsorption.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370615
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 114
    Electronic Resource
    Electronic Resource
    Supercritical CO2 extraction of organic contaminants from aqueous streams (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 944-950 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Supercritical fluid extraction (SCFE) for the removal of organic toxins from water has been studied using a continuous-flow view cell system. Distribution coefficients (ratio of mole fraction of contaminant in supercritical CO2 to mole fraction in the aqueous phase at equilibrium) have been determined for a homologous series of contaminants as individual components in pure water: benzene, phenol, p-chlorophenol, and m-cresol. Data were obtained at two temperatures (313 and 323 K) and over a pressure range of 9.65 to 17.23 MPa for each contaminant. The distribution coefficients of the contaminants follow a pattern that can be explained in terms of molecular interactions both with water in the aqueous phase (as quantified by the pure contaminant solubility in water) and with CO2 in the SCF phase (as quantified by the pure contaminant solubility in near-critical CO2 and crossover phenomena in SCF CO2). These results have been accurately modeled using a hardsphere, perturbation-theory-based Carnahan-Starling-DeSantis-Redlich-Kwong equation of state and simple van der Waals mixing rules.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370617
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 115
    Electronic Resource
    Electronic Resource
    Vapor synthesis of titania powder by titanium tetrachloride oxidation (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1561-1570 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Formation of titania particles by vapor-phase oxidation of titanium tetrachloride was studied in an aerosol reactor between 1,200 and 1,723 K. The effect of process variables (reactor residence time, temperature, and reactant concentration) on powder size and phase characteristic was investigated using the differential mobility particle sizer, scanning electron microscopy, and X-ray diffraction. Titania particles were primarily anatase though the rutile weight fraction increased with increasing reactor temperature. The geometric number average diameter of the particles was between 0.13 and 0.35 μm, and the geometric standard deviation of the particle size distribution was about 1.4. The average particle size increased with increasing temperature, inlet TiCl4 concentration, and residence time. The observed changes in the particle size distribution were compared with those predicted by solving the aerosol dynamic equation by a sectional method and accounting for coagulation and first-order chemical reaction. While variations in the process variables resulted in discernible changes in the size of the particles, the spread of the distribution remained rather unaffected.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371013
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 116
    Electronic Resource
    Electronic Resource
    Masthead (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991) 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 117
    Electronic Resource
    Electronic Resource
    Inaccessible porosity in gasification reactions under kinetic control (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1607-1612 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Random pore models have been successful in interpreting a wide range of experimental observations in gas-solid reactions; however, their applicability has been limited to cases where the entire porous structure is initially accessible to reacting gases. In many practical cases, porous solids contain significant void regions that are initially inaccessible to gaseous reactants, but become accessible in the course of the reaction. A conceptual and mathematical model is developed here that accounts for the existence of this hidden porosity. It uses the same representation of the porous network as was developed in the earlier random pore models, but introduces physically meaningful expressions for the discovery of hidden pores, and the subsequent growth of the discovered pores. The modified model calls for only one additional parameter, the initial volume fraction of hidden porosity in the total volume. It is demonstrated computationally that neglecting hidden porosity can lead to serious underestimations of conversion and reaction rates.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 118
    Electronic Resource
    Electronic Resource
    Effects of operating conditions on longitudinal solids mixing in a circulating fluidized bed riser (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1450-1458 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Longitudinal solids mixing was studied experimentally in circulating fluidized bed risers of internal diameter 0.152 m and 0.305 m. Superficial gas velocity and mean solids flux used were 2.8-5.0 m/s and 5.0-80 kg/m2·s, respectively, and the bed solids had a surface volume mean diameter of 71 μm and a particle density of 2,456 kg/m3. A sodium chloride tracer was used in impulse injection experiments. A simple, one-dimensional dispersion model describes measured solids mixing satisfactorily. Peclet numbers (UoL/Dz) found, in the range 1.0-9.0, were correlated with the riser diameter and mean solids flux. The modeling approach described here permits residence time distribution curves to be calculated directly from the knowledge of superficial gas velocity, mean solids flux, and riser diameter. Longitudinal solids mixing in the riser decreased with increasing riser diameter. The results are consistent with recent hydrodynamic studies.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371003
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 119
    Electronic Resource
    Electronic Resource
    Masthead (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991) 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370101
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 120
    Electronic Resource
    Electronic Resource
    Flow in a converging channel at moderate reynolds numbers (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 59-64 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An analytical solution is found for flow in a converging channel for Reynolds numbers in the range of 102 to 103. The solution applies to an axisymmetric channel, for which the shape is given by R2z=constant, where R is the channel radius at the axial distance z. This shape produces a center-line or core velocity that increases linearly with z, thus making the extensional rate constant. The analytical solution is a pseudosimilarity solution of the axial momentum equation, and its accuracy was gauged by comparison to other results. Comparisons of velocity and pressure distributions to experimental data and to finite-element results indicate that the analytical solution is accurate to about 5%.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370105
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 121
    Electronic Resource
    Electronic Resource
    Simulation of methane partial oxidation over silica-supported MoO3 and V2O5 (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 87-97 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Microkinetic simulations have been carried out to describe the partial oxidation of methane over silica-supported molybdena and vanadia. The objective of this study was to formulate a physically reasonable reaction network to capture the basic aspects of the surface catalytic chemistry and to use this network to link methane oxidation kinetics with the kinetics observed for the oxidation of subsequent gaseous products, i.e., methanol, formaldehyde, and carbon monoxide. The most abundant reactive intermediates on the catalyst surface are suggested to be oxygen and hydroxyl groups. This reaction network successfully predicts the catalytic activities, selectivities, activation energies, and reaction orders observed over silica-supported molybdena and vanadia; and the microkinetic model also semiquantitatively explains the kinetic trends for related catalyst systems and is consistent with surface bonding energetics reported in the literature over various oxide catalysts. The microkinetic reaction network properly reduces to the more simple macrokinetic model reported previously for methane partial oxidation.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370108
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 122
    Electronic Resource
    Electronic Resource
    Effective Kundsen diffusivities in structures of randomly overlapping fibers (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 74-86 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Effective Knudsen diffusion coefficients are presented for fibrous structures consisting of overlapping fibers. The fibers are distributed randomly in d (d=2 or 3) directions with their axes perpendicular to one direction (d=2) or in the three-dimensional space with no preferred orientation (d=3), or they are grouped into d (d=1, 2, or 3) mutually perpendicular bundles of parallel, randomly overlapping fibers. Effective diffusivities are computed using a Monte Carlo simulation scheme to determine the mean square displacement of molecules traveling in the interior of the porous medium for large travel times. Our results show that structures with fibers distributed randomly in d directions have diffusion coefficients identical, within the accuracy of our simulation, to those of d-directional, parallel fiber structures. Effective Knudsen diffusivities are strongly influenced only by the directionality of the fiber structure, with tridirectional or randomly oriented fiber structures presenting lower percolation thresholds (0.04 vs. 0.11) and higher effective diffusivities than bidirectional or random structures with their axes perpendicular to one direction. The tortuosity factor is in general found to decrease with increasing porosity, approaching for each case, as the porosity goes to unity, the corresponding lower bound that is derived using variational principles.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370107
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 123
    Electronic Resource
    Electronic Resource
    Excimer laser-induced deposition of copper films (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 150-154 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370115
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 124
    Electronic Resource
    Electronic Resource
    A critique of two models for cyclone performance (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 285-289 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370217
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 125
    Electronic Resource
    Electronic Resource
    Dynamics of kinetically controlled binary adsorption in a fixed bed (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 299-301 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370219
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 126
    Electronic Resource
    Electronic Resource
    Analysis of microwave heating of materials with temperature-dependent properties (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 313-322 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Transient temperature profiles in multilayer slabs are predicted, by simultaneously solving Maxwell's equations with the heat conduction equation, using Galerkin finite elements. It is assumed that the medium is homogeneous and has temperature-dependent dielectric and thermal properties. The method is illustrated with applications involving the heating of food and polymers with microwaves. The temperature dependence of dielectric properties affects the heating appreciably, as is shown by comparison with a constant property model.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370302
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 127
    Electronic Resource
    Electronic Resource
    Effect of unfavorable continuous phase density gradient on axial mixing (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 360-366 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Field experience with several industrial reciprocating plate liquid-liquid extraction columns indicated that large density gradients in the continuous phase resulted in excessive backmixing. Since there are no published data on the effect of higher density in the upper section compared to lower density in the bottom section of the column, experiments were performed with the calcium chloride brine-water system in a 76.2 mm diameter reciprocating plate column.Axial dispersion coefficients, E, were found to be 10-20 times higher than the values in systems with uniform densities. E decreased with increasing agitation to 30% of the value with no agitation. The effect of increasing flow rate of water up the column was to increase both E and the Peclet number. E was correlated with the density difference between any point in the column and tap water. Another correlation was obtained showing the effects of buoyant and mechanical energy input on axial dispersion.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370306
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 128
    Electronic Resource
    Electronic Resource
    Eddy diffusivity for distillation sieve trays (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 589-596 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An understanding of the eddy diffusivity on a distillation tray is important to accurately predict the distillation tray efficiency from the point efficiency. This article presents a new correlation to predict liquid-phase eddy diffusivity (De) on sieve trays. This correlation has been developed by modeling backmixing as the trajectory motion of liquid droplet elements through the two-phase layer height on the tray. The trajectory model indicates that De is a strong function of the two-phase layer height. An expression for froth height is derived.The new De correlation offers two main improvements over existing literature correlations. First, this model is phenomenologically-based and, therefore, not limited to air/water. Second, the new De correlation gives significantly lower average actual and relative errors and a lower standard deviation of the actual error than do other available correlations.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370412
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 129
    Electronic Resource
    Electronic Resource
    Nonisothermal photochlorination of methyl chloride in the liquid phase (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1471-1484 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A model for the photochlorination of methyl chloride in the liquid phase was developed, with numerical solution and experimental verification. The reaction was carried out under pressure, using carbon tetrachloride as a solvent with polychromatic radiation in a nonisothermal tubular reactor. Momentum, thermal energy, mass and photon balances were established rigorously and solved numerically. Reaction constants were taken from the known reaction mechanistic kinetics in the gas phase. Theoretical results agreed well with bench-scale experiments performed inside an elliptical reflector in the prediction of both reactant conversion and product selectivities. The validated model was used to show the existence of significant temperature and concentration gradients inside the reactor, both in the radial and in the axial directions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371005
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 130
    Electronic Resource
    Electronic Resource
    Reduction of membrane fouling in the ultrafiltration of binary protein mixtures (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1517-1528 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: It is well known that separation efficiency and solute rejection change when two or more proteins are ultrafiltered. This phenomenon is primarily due to membrane fouling and is not significantly influenced by concentration polarization. If membrane fouling is the dominant resistance, then negative transmembrane pressure pulsing might significantly reduce this barrier.A study was performed to determine the effect of negative transmembrane pressure pulsing on solute rejection for an albumin and gamma-globulin mixture in ultrafiltration. Pulsing improved solute flux for all cross-flow rates investigated including turbulent conditions by as much as two orders of magnitude. Under certain pulsing conditions, substantially higher solute flux was obtained for operations involving increased concentration polarization. This study reveals that negative transmembrane pressure pulsing can be effective in lowering the solute flux resistance that is observed in binary protein mixture ultrafiltration.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371009
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 131
    Electronic Resource
    Electronic Resource
    Molecular thermodynamics of solubilities in gas antisolvent crystallization (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1441-1449 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An expanded liquid molecular thermodynamic model is developed to predict the solubilities of pure solids in a liquid expanded with a gaseous antisolvent. Experimental data are presented for systems containing naphthalene, phenanthrene, and a mixture of both in toluene expanded with a gas antisolvent, CO2. The pressure range is 1 to 64 bar and the temperature is 25°C. The data are predicted accurately with regular solution theory up to moderate pressures, but not at the higher pressures where the liquid phase is nearly pure CO2. In contrast, the new expanded liquid equation of state model describes the wide range of behavior from the nearly ideal liquid solution at ambient pressure to the highly nonideal compressible fluid at elevated pressures. As a result, it predicts solubilities accurately over three orders of magnitude by using only binary interaction parameters. The implications of the phase behavior on fractional crystallization with a gas antisolvent are discussed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371002
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 132
    Electronic Resource
    Electronic Resource
    Distributor effects in liquid fluidized beds of low-density particles (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1825-1832 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effect of flow nonuniformities existing near the distributor of a liquid fluidized bed containing very low-density particles (ρs = 1.05 g/mL) has been investigated experimentally. Immobilized enzyme or cell bioreactors operated as liquid fluidized beds often employ low-density particles as the support matrix containing the immobilized biocatalyst. With poorly designed multihole distributors, dead zones can be created which seriously undermine the performance of the bioreactor due to the lack of nutrients. Design guidelines are provided for distributors to minimize the inlet flow disturbances, and hence eliminate potential distributor region problems. As a result, the dispersion model, which is normally used for design purposes, can then be applied.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371207
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 133
    Electronic Resource
    Electronic Resource
    Nuclear magnetic resonance imaging of simulated voids in cement slurries (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1895-1899 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371213
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 134
    Electronic Resource
    Electronic Resource
    Experimental evidence for and prediction of micromixing effects in precipitation (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1698-1710 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The influence of micromixing on precipitation is predicted qualitatively for batch or semibatch precipitations by means of a simplified mixing model, which considers primary nucleation as the main process affected significantly by hydrodynamics. Unwanted micromixing effects are avoided to a maximum in a batch configuration designed to have a volume mixing ratio α close to unity. Using a semibatch precipitator or a batch with a high α value dramatically accentuates mixing interactions. For mixing, changing the feed point location is shown to have much stronger influence than changing the stirring speed and constitutes an efficient test of micromixing. Experimental evidences for these conclusions have been established for calcium oxalate monohydrate batch precipitation. In particular, the early seconds of the reaction (when mainly primary nucleation occurs) have been demonstrated as conditioning the subsequent behavior of the precipitation, even for induction times of a few minutes.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371113
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 135
    Electronic Resource
    Electronic Resource
    Static liquid holdup in packed beds of spherical particles (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1733-1736 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371117
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 136
    Electronic Resource
    Electronic Resource
    Calculating the thermal conductivity of heterogeneous systems (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1739-1743 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371120
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 137
    Electronic Resource
    Electronic Resource
    Transformation of the product set in separation sequence synthesis (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1753-1757 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371123
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 138
    Electronic Resource
    Electronic Resource
    Particle-to-bubble adhesion in gas/liquid/solid slurries (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1801-1809 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: In gas/liquid/solid slurries, adhesion of small particles to gas bubbles is often encountered, for example, during flotation of finely divided minerals and in slurry reactors where particle-to-bubble adhesion may result in an enhanced gas absorption rate (Wimmers, 1987; Lindner, 1988). The adhesion of small particles to gas bubbles in water is studied with a modified bubble pick-up method. The extent of the particle-to-bubble adhesion is revealed in the angle αmax, by which the gas-bubble surface is covered by adhering particles under static conditions. It is shown that αmax depends on the modified Eötvös number, the ratio of the particle and bubble radii, and the effective contact angle θE. It is also found that θE is affected by the curvature of the three-phase contact ring and by the type of the gas.A “particle-to-bubble adhesion” model, indicated by PBA model, based on a balance of forces under static conditions, is developed to calculate the value of θE from the measured values of αmax. The measured values of cos(θE) appeared to be a linear function of the curvature 1/r of the three-phase contact ring which is in accordance with the extended Young-Dupré equation.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371205
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 139
    Electronic Resource
    Electronic Resource
    Propagation of oscillations during ethylene oxidation on a Rh/SiO2 catalyst (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1844-1848 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Infrared imaging is used to visualize nonuniform temperature patterns occurring on a Rh/SiO2 catalyst wafer during the total oxidation of ethylene. Ignition of the catalyst wafer is seen to occur as a propagating reaction front originating at a single point on the wafer. During self-sustained oscillations, the reaction zone contracts, expands, and changes shape. Thermographic data of the oscillations are analyzed by calculating the size and mean temperature of the reaction zone. This analysis reveals that the observed oscillations in the bulk CO2 concentration correlate mainly with changes in the size of the reacting zone.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371209
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 140
    Electronic Resource
    Electronic Resource
    Interrelating excess thermodynamic functions using fusion properties (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 48-58 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new model that interrelates the liquid-phase excess Gibbs energy, enthalpy and volume, called the GHV model, is developed and discussed. The model is based on the fact that most mixtures are immiscible in solid phases and, therefore, have steep solid-phase boundaries. This single assumption allows the model to be applied potentially to all types of mixtures, including organic, metallic, electrolytic and polymeric solutions. The model, which predicts that excess properties are related to one another through various fusion properties, pure component volumes, and enthalpies of fusion in particular, has been applied to a wide variety of organic and liquid metal mixtures. The results show at least qualitative validity without adjustable parameters and more quantitative ability with “effective” fusion properties. The model is also shown to rationalize some sign, magnitude and shape phenomena.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370104
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 141
    Electronic Resource
    Electronic Resource
    High-pressure diffusion measurements by Mach-Zehnder interferometry (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 142-146 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370113
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 142
    Electronic Resource
    Electronic Resource
    Bubble size prediction for rigid and flexible spargers (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 161-168 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: There exists a narrow operating window in bubble columns where the motion is so gentle that the normally dominating forces of coalescence and breakup no longer define the bubble size, hence formation dynamics must control. Elementary force balances are presented to predict bubble size, which compares favorably with experimental data and is shown to be applicable to both rigid and flexible spargers. The main focus is on the prediction and performance of a small-holed flexisparger, for which it is proved that the gas momentum term is highly significant. Also, it is shown that the intermediate drag law is more appropriate than Stokes for forming bubbles.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370202
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 143
    Electronic Resource
    Electronic Resource
    Experimental study of reaction in a partially wetted catalytic pellet (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 202-214 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A single-pellet reactor has been used to investigate the impact of partial external wetting on catalyst performance in a multiphase reaction system. The novel design simulates the local environment within a trickle-bed reactor, and permits the direct measurement of the degree of wetting under reaction conditions. Experimental data of the hydrogenation of α-methylstyrene (AMS) over a Pd/Al2O3 pellet provide unequivocal evidence of effectiveness enhancement by partial wetting, a predicted single-pellet phenomenon (e.g., Harold and Ng, 1987; Funk et al., 1988, 1989). The overall reaction rate is an increasing (decreasing) function of the degree of wetting if the overall limiting reactant is more effectively supplied through the wetted (nonwetted) part of the surface. A maximum in the reaction rate can occur at an intermediate degree of wetting, signaling a transition from an overall AMS-limited to hydrogen-limited reaction. The dependence of the degree of wetting on the liquid flow rate for low reaction rates is consistent with a simple rivulet flow model. At higher reaction rates the degree of wetting decreases, with all other conditions fixed. Possible mechanisms for this interesting link between the degree of wetting and reaction are discussed.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370206
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 144
    Electronic Resource
    Electronic Resource
    Corrections (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 268-268 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370212
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 145
    Electronic Resource
    Electronic Resource
    Critical transport velocity in two-phase, horizontal pipe flow (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 274-276 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370214
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 146
    Electronic Resource
    Electronic Resource
    Enthalpies of combustion, formation, vaporization and sublimation of organics (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 290-298 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370218
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 147
    Electronic Resource
    Electronic Resource
    Electrostatic hazards in powder handling. Glor, Martin, Research Studies Press, Ltd. and John Wiley & Sons, 1988, 171 pp., $59.95 (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 310-310 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370222
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 148
    Electronic Resource
    Electronic Resource
    Modeling and simulation of NOX absorption in pilot-scale packed columns (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 323-339 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Absorption of nitrogen oxides was studied in three packed columns in series. Two were 254 mm ID and 6 m tall, the third was 800 mm ID and 3 m tall. Absorption was also studied in two packed columns of 800 mm ID, 7 and 10 m tall, operated in series. Solutions of mixed nitric and sulfuric acids were used as absorbents. Specific rates of absorption were measured using a stirred cell with a flat interface.A mathematical model is developed for an adiabatic operation. The gas phase reactions and equilibria, gas phase mass transfer, interface equilibria, and liquid phase reactions are included in the model. Heterogeneous gas-liquid equilibria are included in the model for the first time. The variation in the rates of absorption with chemical reaction (of NO2, N2O3, and N2O4) with respect to acid concentration is considered. The formation of nitric acid in the gas phase is also considered in the model. Favorable agreement is shown between the model predictions and the experimental observations.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370303
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 149
    Electronic Resource
    Electronic Resource
    A molecular mechanism for gas hydrate nucleation from ice (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1281-1292 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Induction phenomena are explained that exist in the only two reproducible sets of kinetic data in the literature for gas hydrate formation from an agitated ice surface. The previously unexplained data are interpreted using recent crystal diffraction results. The induction explanation is validated through cyclopropane hydrate kinetic experiments. The induction reasoning forms the basis of an hypothesis for a molecular mechanism of hydrate formation from ice. The hypothesized mechanism is quantified and given physical interpretation. The hypothesis may have significant implications for inhibiting hydrate formation.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370902
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 150
    Electronic Resource
    Electronic Resource
    Modeling and simulation of a honeycomb reactor for high-severity thermal cracking (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1354-1364 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new steam cracking technology has been developed that uses honeycomb-type ceramic reactors with high surface to volume ratios and is heated by flue gas. “Rectangular” process gas temperature profiles are possible with such a reactor. An optimal combination of temperature profile and residence time leads to a very significant increase in olefins yield with respect to conventional cracking units. Benchscale results are compared with predictions based on a reactor model, which accounts in great detail for the geometry of the structure and the associated heat transfer, combined with a rigorous kinetic model based on radical reaction mechanisms.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370908
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 151
    Electronic Resource
    Electronic Resource
    Trapping of solid particles at a wall in a turbulent flow (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1529-1536 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Studies of the motion of a dilute suspension of 100-micron glass and stainless steel spheres in water flowing turbulently down a pipe revealed that they could be trapped in necklace formations that move slowly at a distance of less than one particle diameter from the wall. The tendency toward trapping increases with particle density and decreases with flow rate. The phenomenon is interpreted as occurring when the Saffman lift force toward the wall overcomes the ability of fluid turbulence to mix the particles. The location of the particles is dictated by a balance between the Saffman lift force and a wall-induced force associated with the displacement of fluid as a particle moves parallel to the wall.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371010
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 152
    Electronic Resource
    Electronic Resource
    An improved finite difference method for fixed-bed multicomponent sorption (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 244-254 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A new computational procedure based on the finite difference methods is developed to solve the coupled partial differential equations describing nonisothermal and nonequilibrium sorption of multiple adsorbate systems on a fixed bed that contains bidispersed pellets. In this numerical method, a solution-adaptive gridding technique (SAG) is applied in combination with a four-point quadratic upstream differencing scheme to satisfactorily resolve very sharp concentration and temperature variations occurring in the case of small dispersing effects. Furthermore, the method resorts to a noniterative implicit procedure for solving the coupling between the column transport equations and the adsorption kinetics inside the pellets, which may be particularly efficient when the particle kinetics equations are highly stiff.The numerical model will be tested for one-, two- and three-transition systems. The results are compared to available analytical and equilibrium theory solutions.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370210
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 153
    Electronic Resource
    Electronic Resource
    Closure equations for single and multiple reactions in a CSTR (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 277-280 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370215
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 154
    Electronic Resource
    Electronic Resource
    Letters to the editor (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 307-309 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370221
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 155
    Electronic Resource
    Electronic Resource
    Alternate control structures for chemostat (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 302-306 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370220
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 156
    Electronic Resource
    Electronic Resource
    Shape selective catalysis in industrial applications By N. Y. Chen, William E. Garwood, and Francis G. Dwyer, Marcel Dekker, New York, 1989, 320 pp. $99.75 (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 310-310 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370223
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 157
    Electronic Resource
    Electronic Resource
    Growth and transformation of TiO2 crystallites in aerosol reactor (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 347-359 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Rate process concerning the formation of TiO2 fine crystalline particles by the gas-phase reaction of TiCl4 and O2 are studied using aerosol reactors. Chemical reaction of TiCl4, sintering of particles, mixing of reactants, and transformation from anatase to rutile are evaluated as the system parameters of the simulation model proposed. The crystallite size in the range of 55-65 nm at 1,273 K is predicted well by a model that assumes the maximum fusible particle size, 15 nm in this case.The defect concentration in the TiO2 crystallites strongly affects the transformation rate, and anatase particles produced at 1,173 K are transformed to rutile more rapidly than those produced at 1,373 K. The transformation is simulated quantitatively by the model with the coordinates for elapsed time, particle size and rutile fraction. The model can be applied to such particle production processes as collision, sintering and crystal transformation occurring simultaneously.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370305
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 158
    Electronic Resource
    Electronic Resource
    Hollow fiber contained liquid membrane separation of citric acid (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 383-393 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Citric acid was successfully separated from an aqueous solution using the hollow fiber contained liquid membrane (HFCLM) technique. In this technique, the organic liquid membrane is contained in the shell side between two sets of hollow fibers; feed solution flows through one set of fibers and the strip solution flows through the other set. Tri-n-octylamine diluted in various organic solvents was used as a complexing agent for facilitated transport of citric acid from an aqueous solution. Pure water and aqueous sodium hydroxide were used as stripping agents. Membrane life and stability problems encountered in supported liquid membranes are eliminated. A mathematical model of facilitated solute transport through HFCLM that accounts for the interfacial reversible reaction kinetics and diffusion process inherent in carrier-facilitated transport is presented. Experimental data agreed well with the theoretical predictions for permeators achieving almost complete solute recovery.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370309
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 159
    Electronic Resource
    Electronic Resource
    Design and economic trade-offs of extractive crystallization processes (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 437-447 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A systematic procedure is formulated for the separation of a binary mixture by means of extractive crystallization. It shous that two flowsheet structures can handle systems with a wide variety of solid-liquid phase behaviors, including components with simple eutectics, multiple eutectics, and compound formation. Design equations are presented for both flowsheet structures. In addition, design variables and constraints are identified. The economic trade-offs in extractive crystallization processes are examined through the analysis of an example: the complete separation of paraxylene from meta-xylene using n-pentane as the extractive solvent. Comparison of our general methodology with the system-specific designs reported in the literature shows that the latter are process alternatives of the former.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370313
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 160
    Electronic Resource
    Electronic Resource
    Solid distribution in a slurry bubble column with two immiscible liquid phases (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 466-469 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370317
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 161
    Electronic Resource
    Electronic Resource
    Methods of deterministic chaos applied to the flow of thin wavy films (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 481-489 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The structure of thin, wavy falling films was studied to evaluate whether the random-appearing wave structure is a result of deterministic chaos or a purely stochastic process. The time-varying film thickness was obtained at different spatial locations near the point of wave inception for flow rates in the range of Re=3-10. Under all conditions the wave structure was aperiodic in nature and displayed none of the known transitions to chaos. However, the power spectra followed an exponential decay law at high frequencies that is characteristic of chaotic systems. The estimated attractor dimension, used to characterize the complexity of a chaotic system, was much higher than those of known model chaotic systems. It is demonstrated that these high values could be explained due to small levels of noise present in experimental situations. Since experimental data are seldom noise free, a basic limitation in applying these methods to experimental measurements is demonstrated.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370402
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 162
    Electronic Resource
    Electronic Resource
    Inversion and zero dynamics in nonlinear multivariable control (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 527-538 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This work concerns general multiple-input/multiple-output (MIMO) nonlinear systems with nonsingular characteristic matrix. For these systems, the problem of inversion is revisited and explicit formulas are derived for the full-order and the reduced inverse system. The reduced inverse naturally leads to an explicit calculation of the unforced zero dynamics of the system and the definition of a concept of forced zero dynamics. These concepts generalize the notion of transmission zeros for MIMO linear systems in a nonlinear setting. Chemical engineering examples are given to illustrate the calculation of zero dynamics. Input/output linearization is then interpreted as canceling the forced zero dynamics of the system, and precise internal stability conditions are derived for the closed-loop system.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370406
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 163
    Electronic Resource
    Electronic Resource
    A Monte Carlo analysis of acid hydrolysis of glycosidic bonds in polysaccharides (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 905-914 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Kinetic experiments for the hydrolytic depolymerization of cellobiose and amylose were performed in acidic medium. In the case of amylose, only the production rate of glucose was monitored. Then, a Monte Carlo procedure was developed to simulate long-chain saccharide acid hydrolysis using the kinetic information obtained from the model compound, cellobiose. This stochastic procedure, which is applicable to the homogeneous acid hydrolysis of highly amorphous polysaccharides of sufficient degree of polymerization, provides estimated curves for the time evolution of all intermediate products. Literature data on the hydrolysis of oligoxylans were also compared to the results obtained from the Monte Carlo procedure. The depolymerization of linear polysaccharides, which should normally be viewed as a nonhomogeneous Markov chain, could be considered as a homogeneous Markov chain, provided that the chain is visited at specifically determined time intervals.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370613
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 164
    Electronic Resource
    Electronic Resource
    Characteristics of gas-liquid-solid fluidization with nonwettable particles (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 951-952 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370618
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 165
    Electronic Resource
    Electronic Resource
    Modeling of reaction-induced flow maldistributions in packed beds (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1035-1052 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This work examines reaction-induced flow maldistributions in adiabatic, downflow packed beds. Using linear stability analysis it is shown that for the case of a constant heat source, the uniform flow loses stability when a certain dimensionless group, the Darcy buoyancy number, exceeds a critical value. Center manifold theory is used to analyze the local bifurcation picture for the case of a simple and double zero eigenvalue. It is found that for large Peclet numbers, all the bifurcations from the uniform solution are subcritical in nature and are unstable locally. Orthogonal collocation and continuation techniques are combined with the local theory to determine the various branches of bifurcating solutions. The temperature and flow distributions of stable and unstable solution branches are presented for several aspect ratios and Peclet numbers. Numerical simulations predict direct transitions from uniform flow to periodic or chaotic flows. It is also found that there is a wide range of the Darcy buoyancy number in which the uniform and maldistributed flows are stable and coexist.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370709
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 166
    Electronic Resource
    Electronic Resource
    Unreachable roots for global homotopy continuation methods (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1093-1095 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370713
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 167
    Electronic Resource
    Electronic Resource
    Lattice relaxation in type I gas hydrates (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1511-1516 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Computer simulations have been used to examine the approximations upon which the van der Waals-Platteeuw theory of hydrate stability is based, and in particular, the extent to which the water lattice relaxes about the guest molecules. It is found that the behavior of the water lattice depends significantly on both the nature and number of guest molecules present - an effect that is neglected in the van der Waals-Platteeuw theory. The simulations also indicate an important role for the repulsive guest-host interactions in generating the mechanical stability of gas hydrates in the bulk. On the basis of these simulations, it is conjectured that surface interactions (particularly at a water/guest interface) are fundamental to the phase behavior of gas hydrates.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371008
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 168
    Electronic Resource
    Electronic Resource
    Stability of SISO quadratic dynamic matrix control with hard output constraints (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1550-1560 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The inclusion of output constraints in the on-line optimization problem solved by quadratic dynamic matrix control (QDMC) can result in a unstable, closed-loop system, even when the corresponding unconstrained algorithm is stable. The presence of constraints in the optimization problem produces a nonlinear, closed-loop system, although the plant and model dynamics are assumed linear. This article quantifies the effect of output constraints on both nominal and robust stability for single-input/single-output processes. Stability conditions provided can be used to select the QDMC parameters and constraint window. Examples demonstrate that these conditions can capture the nonlinear effect of the constraints and that tuning rules developed for the unconstrained case should not be used with output constraints. An example with dead time error illustrates the use of this framework to guarantee the robustness of constrained QDMC with respect to modeling error.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371012
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 169
    Electronic Resource
    Electronic Resource
    An efficient design method for binary, azeotropic, batch distillation columns (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1571-1578 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Using rigorous models to simulate batch distillation involves the solution of many stiff differential equations. The dimensionality of the problem also increases with an increase in the number of plates and components, which imposes limitations on the use of rigorous models. Furthermore, problems in design, optimization, synthesis, and control involve iterative procedures, and considerable computational efforts would be required to solve them rigorously. As an alternative, the short-cut method (Diwekar and Madhavan, 1991a) provided reasonably accurate solutions without much computational effort. This method in the present form, however, cannot be applied to azeotropic systems because of the impassable barrier of the azeotropic point and needs to be modified. The azeotropic approximation proposed by Anderson and Doherty (1984) was used to modify the short-cut method for binary azeotropic systems. The modified algorithm presented here was tested extensively with a number of binary azeotropic systems for both constant reflux and variable reflux modes of operation, and the results were shown to compare well with the rigorous models. The method requires significantly less computational efforts and is very useful in analyzing feasible region of operation.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371014
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 170
    Electronic Resource
    Electronic Resource
    Circulation in bubble columns: Corrections for distorted bubble shape (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1593-1594 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371018
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 171
    Electronic Resource
    Electronic Resource
    Reactions of polycyclic alkylaromatics: Structure and reactivity (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1613-1624 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A family of alkyl-substituted polycyclic aromatic hydrocarbons was pyrolyzed in microbatch reactors at temperatures between 350°C and 425°C. A general pyrolysis network was deduced for these compounds, and it comprised two major and one minor parallel pathways. The first major pathway resulted in products analogous to the major products observed from alkylbenzene pyrolysis. The second major pathway led to products via the cleavage of the strong aryl-alkyl C—C bond. The third pathway led to small amounts of products, presumably through cyclization and condensation reactions. The relative importance of the two major pathways varied for the different compounds. The rates of aryl-alkyl bond cleavage differed for the different compounds, and these rates were quantitatively related to the compounds' localization energies through Dewar reactivity numbers.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371104
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 172
    Electronic Resource
    Electronic Resource
    Nonlinear analysis in process design (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1-38 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: As steady-state and dynamic simulators with optimal controllers have evolved, tools for nonlinear analysis have been developed by reactor and thermophysical property specialists. Designers lag behind in developing and utilizing these tools, as many design strategies assume idealized behavior even though processes contain an increasing number of nonlinear elements. This article examines the sources of the nonlinear elements, often associated with physical and chemical interactions, in designs and their control systems. Promising methods for nonlinear analysis are reviewed.In each design activity, involving simulation, economic optimization, projections of controllability and operability, emphasis is on the sources of nonlinearities and solution methods. These are examined for the equality constraints and nonlinear programs in phase and chemical equilibria, in reactors and separators, and in the simulation and optimization of flowsheets. Also examined are the impact of non-linear predictive control in screening designs and methods to insure operability, in the face of uncertainties.
    Additional Material: 27 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370102
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 173
    Electronic Resource
    Electronic Resource
    Development of the AVEC model for associating mixtures using NMR spectroscopy (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 65-73 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Common models for excess Gibbs energy account primarily for physical forces and do not represent strong specific interactions. However, purely chemical models neglect strong nonspecific forces and combined chemical-physical treatments involve an unreasonable number of adjustable parameters. One way to ameliorate this limitation is to make independent measurements of the parameters by a nonther-modynamic technique. We report an investigation of hydrogen bonding, a localized and very directional specific interaction, conducted in various alcohol mixtures using Fourier transform nuclear magnetic resonance to measure the number of complexed species in solution. A chemical-physical association model with variable equilibrium constants has been developed. The distinguishing feature of this model is that the species in solution do not have equal probability of forming yet require only a single chemical interaction parameter determined from fitting NMR data and a physical interaction parameter determined from infinite dilution activity coefficients. The AVEC model successfully predicts vapor-liquid equilibrium and excess enthalphy as well as liquid-liquid equilibrium, an especially stringent test.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370106
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 174
    Electronic Resource
    Electronic Resource
    Void wave propagation phenomena in two-phase flow (Kern Award Lecture) (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 123-135 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A detailed linear and nonlinear analysis of void wave phenomena in two-phase flow is presented. A state-of-the-art, one-dimensional two-fluid model was used as the basis for this analysis. It is shown that void wave dispersion is strongly influenced by phasic slip. In particular, the smaller the slip the more dispersion occurs. It has also been found that nonlinear wave forms, such as shocks and solitons, may occur. Moreover, the virtual mass force was found to be an important parameter in the modeling of void waves. It is shown that void wave analysis is an excellent means of assessing the closure assumptions used in two-fluid models. It is also implied that carefully taken void wave data are needed for this purpose.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370111
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 175
    Electronic Resource
    Electronic Resource
    Nonrandom factor model for electrolyte solutions (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 147-149 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370114
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 176
    Electronic Resource
    Electronic Resource
    Data reconciliation in generalized linear dynamic systems (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 193-201 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A generalized linear dynamic model or singular model, for which the standard state space representation and the Kalman filtering cannot be applied, is used to develop a new algorithm to solve the linear dynamic material balance problem. This algorithm is based on the method developed in the steady-state case and leads to a recursive scheme, which is very useful in real-time processing. It reduces the computational problem such as singularities and round-off errors that may occur in complex systems. Convergence conditions are given and verified for the dynamic material balance case.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370205
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 177
    Electronic Resource
    Electronic Resource
    Modeling of supercritical desorbers with an equation-of-state-based isotherm (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 215-224 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An equation-of-state-based sorption isotherm is developed and used in modeling isothermal supercritical fluid desorption in fixed beds. The conventional fixed-bed desorber model when coupled with density-dependent sorption isotherm predicts the temperature, pressure, and density effects on desorber dynamics and regeneration efficiencies that are experimentally observed in supercritical fluid regeneration of fixed beds.Experimentally observed phenomena such as the presence of pressure-dependent optimal regeneration temperature, high-pressure-favored regeneration, and the reversal of temperature dependence of sorption isotherm - which formerly were attributed to supercritical fluid density and viscosity, and to the endothermicity of sorption isotherm - were fully predicted and explained in terms of a density-dependent sorption isotherm.The proposed method also promises prediction of regeneration efficiencies in cosolvent-aided supercritical fluid desorption.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370207
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 178
    Electronic Resource
    Electronic Resource
    Use of Hammerstein models in identification of nonlinear systems (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 255-268 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The utility of the Hammerstein model, which is composed of a static nonlinear element in series with a linear dynamic part, was investigated to represent the dynamics of nonlinear chemical processes. Different methods to identify the parameters of Hammerstein models were tested. The methods were applied to the identification of simulated distillation columns and to an experimental heat exchanger process. The results show that the dynamics of such processes can be better represented by Hammerstein-type models than by linear models.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370211
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 179
    Electronic Resource
    Electronic Resource
    Mixing in fed-batch and continuous flow processes in nonstandard geometries (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 269-273 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370213
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 180
    Electronic Resource
    Electronic Resource
    Effect of dispersion quality on particulate magnetic recording disk properties (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 394-402 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The production of particulate magnetic disks or tapes requires consistent and uniform magnetic characteristics over the entire disk or tape to have as few defects as possible. To achieve this goal, the magnetic particle suspension used to coat the disk must be well dispersed. This article describes the use of a rheomagnetic instrument that provides an indirect measurement of the dispersion quality prior to coating application. The instrument was designed, tested, and put on a manufacturing scale line to characterize the relationships between the measured dispersion quality and functional characteristics of the magnetic coating. The results of tests done during scaleup for production yielded a qualitative correlation between the in-situ measurements made on the magnetic particle suspension at the coater with the surface roughness due to flocs, the on-disk orientation ratio, and the signal to noise ratio. The current results are the first demonstration of the dispersion quality measurement in a practical manufacturing environment.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370310
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 181
    Electronic Resource
    Electronic Resource
    Applicability of Cullinan's equation for liquid binary diffusivities (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 470-474 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370318
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 182
    Electronic Resource
    Electronic Resource
    Enhanced dispersion resulting from solute exchange between phases (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 512-526 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The enhanced dispersion resulting from solute exchange between phases was investigated experimentally for the case of a long, cylindrical capillary tube, in which a stationary absorbing phase formed a thin annular film around a flowing fluid. Solute diffusion into the stationary phase was analyzed in detail to accurately determine the coupling of film diffusion and hydrodynamic effects. The experimental results and analyses showed an increase in dispersion relative to the usual Taylor effect. The increased dispersion was a function of the relative partitioning of solute between phases and was in quantitative agreement with predictions from previously published theoretical studies.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370405
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 183
    Electronic Resource
    Electronic Resource
    Photon absorption by aqueous TiO2 dispersion contained in a stirred photoreactor (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1096-1100 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370714
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 184
    Electronic Resource
    Electronic Resource
    Masthead (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991) 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370801
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 185
    Electronic Resource
    Electronic Resource
    Effect of cationic electrolytes on the deposition rate of Brownian particles (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1113-1116 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370718
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 186
    Electronic Resource
    Electronic Resource
    Equivalent annular model of a multitubular shell-side (MSS) fixed-bed reactor (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1129-1138 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: For a multitube catalytic reactor in which catalyst occupies the shell side of the cooling tubes, a two-dimensional model is developed to determine the nonuniform radial distribution of the temperature and concentration. The cross-section of the fixed bed is divided into a number of equivalent portions proportional to the number of cooling tubes. Each portion is approximated by either an equivalent annular fixed bed or a transformed circular fixed bed in the complex plane. Enthalpy and mass balances are performed on the equivalent annular fixed bed while the radially varying flow distribution and the transport properties are considered in a transformed circular fixed bed. A correlation is developed for the equivalent annular model based on the relationship of the two different approximations. The model can also account for variations in radial porosity, radial velocity, and transport properties.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370803
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 187
    Electronic Resource
    Electronic Resource
    Prediction of the critical volume from the van der Waals volume (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1107-1108 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370716
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 188
    Electronic Resource
    Electronic Resource
    Mathematical model of a gas diffusion electrode bonded to a polymer electrolyte (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1151-1163 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A mathematical model for an ion-exchange membrane attached to a gas-fed porous electrode is derived and discussed. The model is applied to simulate the oxygen electrode of a polymer-electrolyte fuel cell. Our discussion focuses on cell polarization characteristics, water transport, and catalyst utilization - all of which must be considered for fuel-cell design. Calculated polarization behavior is shown to compare favorably with published experimental data. Our results indicate that if the membrane maintains full saturation, its contribution to the total cell resistance is most significant at higher operating current densities (greater than 200 mA/cm2). Polarization resistance due to the oxygen reduction reaction appears to be important for all practical current densities. Water transport, driven by pressure and electric-potential forces, is shown to be a complicated function of the cell operating conditions. The utilization and distribution of noble-metal catalyst is discussed.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370805
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 189
    Electronic Resource
    Electronic Resource
    Knudsen diffusivities and properties of structures of unidirectional fibers (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1175-1186 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Effective Knudsen diffusion coefficients are presented for fibrous structures consisting of parallel, nonoverlapping or partially overlapping fibers. They are computed by means of a Monte Carlo simulation scheme which is employed to determine the mean square displacement of molecules travelling in the interior of the porous medium for large travel times. The results show that structures of paralle, non-overlapping fibers have smaller effective diffusion coefficients parallel to the fibers than structures of parallel, randomly overlapping fibers of the same porosity and fiber radius, but larger in directions perpendicular to the fibers. Partially overlapping fiber structures are found to exhibit behavior intermediate to those of the two extreme cases. Molecular trajectory computations are also used to obtain results for the structural properties of partially overlapping fiber structures (e.g., porosity and internal surface area, accessible porosity and internal surface area, and percolation threshold), which are compared with some results of the literature for the equivalent problem of partially overlapping disks on a plane.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370807
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 190
    Electronic Resource
    Electronic Resource
    Melt crystallization: Process analysis and optimization (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1205-1218 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Melt crystallization manufacturing systems are characterized mathematically and optimized. Directional solidification and sweating are modeled, and the results are correlated to plant data. A nonlinear programming algorithm is constructed to determine the optimal design and operation of a production plant. Process constraints include product purity, process yield, capital cost, phase equilibria, kinetic, and operational factors. An objective function is constructed from scaled yield and capital outlay formulae, and is optimized over a variably constrained feasible space. The dependence of the optima on the separation distribution coefficients and on the constraints is given for specific one-stage examples for three operational regimes. The one-stage analyses are applied for the solution of the n-stage problem.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370810
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 191
    Electronic Resource
    Electronic Resource
    Single-pore model: A simplified diffusion simulation (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1245-1248 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370815
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 192
    Electronic Resource
    Electronic Resource
    An accurate one-dimensional model for nonadiabatic annular reactors (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1265-1269 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370819
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 193
    Electronic Resource
    Electronic Resource
    Nucleation and growth of succinic acid in a batch cooling crystallizer (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1293-1304 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A method to evaluate nucleation and crystal growth rates from batch cooling crystallization experiments is presented. Solute concentration and suspension temperature are recorded during the experiment and the product crystal size distribution is analyzed. The crystal growth and nucleation rates at any instant are calculated by solving the population balance equation using the method of characteristics, together with the mass balance equation. Based on a set of different cooling crystallization experiments, kinetics for succinic acid are determined. Applying these kinetics in process simulation allows for a reasonably accurate prediction of the product weight mean size.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370903
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 194
    Electronic Resource
    Electronic Resource
    Equation of state for pure fluids and mixtures based on a truncated virial expansion (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1379-1391 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: An accurate, yet simple, equation of state was developed for pure fluids ranging from nonpolar to H2O and their mixtures. The equation consists of a virial expansion truncated after the fourth virial coefficient and a closed-form term approximating higher coefficients. For nonpolar or weakly polar compounds, the equation is generalized using critical temperature, critical pressure, and acentric factor. Despite its simplicity, the equation represents the P-V-T and saturation properties of pure fluids with a very good accuracy, which is comparable to that of multiparameter, generalized BWR-type equations. For mixture calculations, mixing rules were formulated based on the rigorously known composition dependence of virial coefficients. The equation represents vapor-liquid, gas-gas and liquid-liquid equilibria, as well as volumetric properties of mixtures containing nonpolar components and/or water. Binary parameters can be generalized for series of mixtures containing a common component.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690370910
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 195
    Electronic Resource
    Electronic Resource
    Adaptive generic model control: Dual composition control of distillation (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1634-1644 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Generic model control (GMC) takes care of parametric mismatch for underdamped, closed-loop specification, whereas robust generic model control (RGMC) can handle parametric mismatch for any closed-loop specification. But, neither GMC nor RGMC is capable of compensating for structural mismatch. In this study, adaptive GMC(AGMC) and adaptive RGMC (ARGMC) structures are proposed, and their effectiveness over GMC and RGMC is demonstrated with several examples. AGMC exhibits better performance over ARGMC, GMC, and RGMC in all the cases of no process/model mismatch, parametric mismatch as well as structural mismatch.Distillation adaptive generic model control (DAGMC) structure is also proposed for dual composition control of distillation. Since embedding of distillation state-space model in the basic GMC law is practically impossible, linear and nonlinear models are proposed with adaptation using distillation process data, and DAGMC is applied to two typical nontrivial distillation units. Nonlinear DAGMC exhibited better performance over linear DAGMC.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371106
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 196
    Electronic Resource
    Electronic Resource
    One-dimensional numerical model for a spray column heat exchanger (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1673-1679 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A numerical model describing performance of a liquid-liquid spray column heat exchanger is developed. The model is for a disperse packed column operating in steady state. The fundamental equations for the continuous and distributed phases are developed in Eulerian and Lagrangian forms, respectively. The model predicts simultaneously the volume fraction, velocity, and temperature for each phase. Energy and momentum are exchanged between phases through source variables. Empiricism in the model is limited to the specification of droplet drag coefficient and Nusselt number correlations which are utilized to calculate momentum and energy source terms. Application of the computer model to column operation yields predictions that compare closely with experimental results.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371110
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 197
    Electronic Resource
    Electronic Resource
    Dynamic structural transformation for the analysis of distillation control structures (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1725-1729 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371115
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 198
    Electronic Resource
    Electronic Resource
    Diffusive and convective protein transport through asymmetric membranes (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1497-1510 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Experimental data are obtained for bovine serum albumin transport through asymmetric polyethersulfone ultrafiltration membranes of differing molecular weight cutoff in a stirred ultrafiltration device. The actual membrane sieving coefficient is determined from filtrate concentration measurements using a stagnant film model to account for bulk mass transport effects. These sieving coefficients are then used to evaluate the relative contributions of diffusive and convective transport to the overall protein flux. The results are in good agreement with available hydrodynamic models for the hindrance factors for convective and diffusive transport of spherical solutes through well-defined pores, with the effective solute to pore size ratio evaluated from a partitioning model that explicitly accounts for the ellipsoidal shape of the protein and the membrane pore size distribution. The implications of these results to the analysis of experimental data for membrane sieving and to the design of effective protein fractionation devices are also discussed.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371007
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 199
    Electronic Resource
    Electronic Resource
    Oscillatory cross-flow electrophoresis (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1537-1549 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Electrophoresis is a useful analytic technique for the separation of proteins and other large molecules, but has proven resistant to scale-up to production levels. In this article we describe a new technique that permits the use of much greater feed rates than possible in a conventional electrophoresis unit. The technique, in its simplest form similar to the cyclical field-flow fractionation technique developed by Giddings (1986) and extended by Shmidt and Cheh (1990), relies on the application of an oscillatory electric field across the narrow gap of the electrophoretic cell. The motion of the solute species induced by this field interacts with an oscillatory cross-flow to cause a separation based on the electrophoretic mobility of the species. This horizontal separation is combined further with a gradient in the strength of the oscillating electric field and oscillations in the vertical downflow to lead to different steady streamlines for species with different mobilities.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371011
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 200
    Electronic Resource
    Electronic Resource
    A generalized Blake-Kozeny equation for multisized spherical particles (1991)
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 37 (1991), S. 1583-1588 
    Details
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/aic.690371016
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...