Library

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • 1965-1969  (3,474)
  • Life and Medical Sciences  (2,026)
  • Chemical Engineering  (1,448)
Material
Years
Year
  • 101
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 866-872 
    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 local volume average of the equation of motion is taken for an incompressible fluid flowing through a porous structure under conditions such that inertial effects may be neglected. The result has two terms beyond a pressure gradient: g, the force per unit volume which a flowing fluid exerts on a porous structure, and the divergence of the local volume-averaged extra stress tensor (viscous portion of the stress tensor).Constitutive equations for g are examined with the aid of the principle of material indifference. When g is assumed to be a function of the velocity of the fluid relative to the solid as well as various scalars, the usual results for a nonoriented (isotropic) porous structure are obtained. When g is assumed to be a function of the local porosity gradient as well, we derive a new expression for g applicable to oriented (anisotropic) porous structures.For a Newtonian fluid with a constant viscosity, the divergence of the local volume-averaged extra stress tensor is proportional to the Laplacian of the averaged velocity vector. Boundary conditions for the averaged velocity vector are discussed. Three problems are solved for the flow of an incompressible Newtonian fluid in a nonoriented permeable medium. These solutions, as well as an order-of-magnitude analysis, suggest that we may often neglect both the Laplacian of average velocity and the boundary conditions for the tangential components of averaged velocity at an impermeable wall.Two specific constitutive equations for g are proposed for the flow of incompressible Noll simple fluids in nonoriented porous structures. Flow through a porous medium bounded by an impermeable cylindrical surface is solved for these two constitutive equations, and the results are compared with previously available experimental data.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 102
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 3-155 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 103
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 4-10 
    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 dye tracer technique was utilized to measure the residence time distribution of the drops in a spray column, operating with a dispersed or a dense packing of drops, for a wide range of flow rates, in a 15 cm.in diameter, 150 to 160 cm. long column proper.For dispersed packing of drops and for flow rates below the onset of coalescence, the flow of the drops was approximately plug flow, with a variance of the residence time distribution of 0.095. For flow rates above the onset of coalescence within the column, the variance increased sharply to 0.55 and decreased at higher flow rates.For dense packing of drops the variance of the residence time distribution was in the range of 0.1 to 0.5. This variance is attributed to the effect of bypassing water and kerosene near the wall of the column. A mathematical model based on this effect showed reasonable fit with the experimental results. This model predicts an approach to plug flow of the drops for large diameter columns.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 104
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 57-63 
    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 sensitivity matrix is defined as a measure of trajectory deviations to small parameter variations of both open and closed loop controlled nonlinear parabolic and first-order hyperbolic systems. In general the parameters may enter through the system equations or the boundary conditions and may be time or spatially dependent. The introduction of a positive measure of the sensitivity, the norm of the sensitivity matrix, into the performance index is shown to be effective in limiting the trajectory deviations due to the parameter variations. The open and closed loop control of a double pipe heat exchanger is analyzed with the open loop problem solved by an approximate procedure. The sensitivity reformulation is successful in reducing trajectory sensitivity, however at the cost of decreased overall performance.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 105
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 81-85 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Axial dispersion was studied experimentally for turbulent flow through a 1 1/4-in. piping system containing 90 deg. elbows. The Reynolds number range was 15,400 to 96,555. The imperfect pulse tracer technique was used with the axial dispersion numbers being obtained from the difference in variances of concentration-time curves observed at two points in the system.Elbows interconnected by short lengths of pipe with each succeeding one reversed so as to cause a change in the direction of flow, increased axial dispersion by 35 to 61% over that expected for straight pipe, while the same elbows turned so as to form a helix decreased the dispersion substantially; however, the amount of axial dispersion was still 8 to 22% greater than that observed for straight pipe.The equivalent lengths of the elbows depend upon both their arrangement and the Reynolds number. Closely placed, helically arranged elbows required equivalent lengths of from 2.9 to 5.1 diam., while a reversed arrangement required 6.9 to 11.6 diam. Elbows separated by a developing length and randomly arranged yielded an equivalent length range of 3.6 to 10.6 diam. The geometical l/d ratio of the elbows used was 2.05.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 106
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 100-105 
    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 region into which particles arrive in a random manner, remain a random amount of time, and then leave is considered. This model is used in penetration theories of heat and mass transfer. From observations of the number of particles present at any time, it is desired to estimate arrival and exit statistics, residence time statistics, and average rates of transfer across the region. Assuming arrival is a Poisson process, equations governing the above statistics are derived. Some problems in spectral analysis arising from the use of nondifferentiable stochastic processes are solved. Estimators for important parameters are discussed, and it is shown that generally they are biased. A derivation linking the rate of transfer across the region with the rates of transfer of particles is obtained and compared with other such results.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 107
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 126-127 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 108
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Differential equations were derived to describe the system characterized by a rapid, irreversible reaction of a fluid species in a flowing fluid with a fixed bed of solids in which the reaction rate was controlled by mass transfer of the reacting fluid from the bulk fluid to the reaction site in the solid. Two kinds of mass transfer resistances were assumed, external or film diffusion resistance, and internal pore diffusion resistance. The set of differential equations were solved by a finite-difference method for both the generalized case and for the specific case of reaction of hydrogen in a stream of helium with fixed beds of copper oxide pellets.The hydrogen-copper oxide reaction is one step in a proposed method for removal of hydrogen as a contaminant in the helium coolant of nuclear reactors. This reaction was experimentally investigated in tests with both differential and deep beds of copper oxide in the temperature range of 400 to 600°C., at pressures of 10.2 to 30.0 atm., with gas mass flow rates of 0.0050 to 0.050 g./sq.cm.-sec, and with inlet hydrogen concentrations of 0.0008 to 1.21 vol. %. These tests showed that the system could be described by the two rate-limiting steps: film and pore diffusion of hydrogen. Differential-bed tests were used to establish hydrogen transport properties within the porous copper oxide pellets, and tests with deep beds were used to establish external mass transport properties.Generalized breakthrough curves were determined by a computer solution of the mathematical model. These curves can be the basis for design of fixed-bed copper oxide oxidizers for gas-cooled, nuclear reactor purification systems and for design of any fixed-bed system which follows the assumed reaction mechanism.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 109
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 133-135 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 110
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 136-137 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 111
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 144-146 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 112
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969) 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 113
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 114
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 171-177 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Liapunov's direct method is used to establish a finite region of asymptotic stability for nonlinear systems with an arbitrary number of state variables. The procedure is a geometric one in multidimensional space which uses the Fletcher-Powell minimization technique to find the maximum time derivative of the Liapunov function on the closed Liapunov hypersurface. Three detailed examples are presented, the first being the classical 2-variable CSTR with heat transfer and the third being a 32-variable 16-stage model of an adiabatic tubular reactor with axial diffusion.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 115
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 194-199 
    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 shell progressive kinetic model is used to determine the temperature rise in a spherical pellet for a gas-solid diffusion controlled reaction. The effects of heat and mass transfer resistances in the gas film as well as inside the pellet are investigated. The predicted temperature rise may be severe enough to cause sintering to catalyst pellets in which reactions such as combustion of coke occur.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 116
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 220-226 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 117
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 208-214 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Experiments have been carried out to measure the permeation of tritium-labeled toluene through polyethylene films fully swollen with chlorobenzene, mesitylene, cumene, toluene, ethylbenzene, cyclohexane, tetrahydronaphthalene, and decahydronaphthalene. The results show characteristic Arrhenius temperature dependence over the range 25 to 40°C. The permeation of toluene through the films appears to be enhanced by increased solubility of the swelling agent (estimated from the work of others) in the film and there also appears to be a rough correlation between permeability of toluene and the boiling points and vapor pressures of the swelling agents. The range of permeabilities measured at 25°C. is 2.09 × 10-7 to 0.51 × 10-7 sq.cm./sec., the extremes of measured permeation activation energy, Ep, are 11.41 to 16.68 kcal./mole, and the pre-exponential factor, Po, falls within the interval 36.59 to 1.29 × 105 sq.cm./sec. A very definite linear relationship or compensation effect is evident between Po and Ep. Except as mentioned above, none of these quantities appears to correlate uniformly with the following properties of swelling solvent: molecular weight, dipole moment, specific gravity, vapor pressure, boiling point, heat of vaporization, critical temperature, viscosity, surface tension, molar volume, molecular area or other molecular dimensions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 118
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 245-249 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Oxidation-reduction rates have been determined in stirred liquid-liquid systems wherein tetravalent cerium ions in a continuous aqueous phase were reduced by tetrachlorohydroquinone contained in dispersed organic droplets. Kinetic data obtained (using low volume fractions (〈0.06) of dispersed organic phase) indicate that the rate of reduction of ceric cerium is proportional to the extent of the interfacial area of the stirred liquid-liquid system. Two possible rate-limiting mechanisms are discussed to explain the observed kinetic behavior.This liquid-liquid electron exchange system might find potential use as a chemical tool for measuring changes in interfacial area as influenced by various mixing parameters.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 119
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 256-263 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Pressure-temperature data were obtained along isenthalps for nitrogen, methane, and three ternary nitrogen-methane-ethane mixtures. These data were differentiated to obtain Joule-Thomson coefficients over the temperature range from ambient to 200°K. and at pressures from 165 atm. to about 5 atm. Data for nitrogen was obtained down to 140°K.The resulting Joule-Thomson coefficients were compared with predictions based on the Beattie-Bridgeman and Benedict-Webb-Rubin equations of state and on the virial equation of state truncated after the third virial coefficient. These comparisons show that the Benedict-Webb-Rubin equation could predict the data with a deviation averaging 1.7%. The Beattie-Bridgeman predictions were highly dependent upon the mixture rules used, with the best set of mixture rules giving an absolute average deviation of 4.8%. Predictions using the virial equation with virial constants obtained from the Lennard-Jones potential energy function using a geometric mean minimum potential energy deviated from the experimental data by 5%.In all of these comparisons, the virial coefficients of ethane appear to be in greatest uncertainty, and the predictions of mixture data high in ethane least satisfactory. Thus it appears that improved data on the pure components, particularly ethane, are vital to any satisfactory evaluation of mixture properties.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 120
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 281-288 
    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 effects of ultrasonic vibrations on heat transfer to water and methanol by natural convection and by boiling were measured at three ultrasonic energy levels with frequency ranging from 20.6 to 306 kcycles/sec., using electrically heated platinum wires of diameters 0.007 and 0.010 in. Up to an eight-fold increase in heat transfer coefficient was obtained in natural convection, but the effects diminished with increased temperature difference and became negligible in the well-developed nucleate boiling region. High-speed photographs showed that the increase was due to the motion of cavitation bubbles on the wire surface. The heat transfer results were correlated by local cavitation activity values measured by a technique developed for this work.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 121
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 301-303 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 122
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 475-476 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 123
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 323-327 
    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 laser doppler flowmeter is used to obtain velocity profiles in circular glass tubes downstream from a plug composed of brass screens. The apparatus for measuring point velocities of particles suspended in a fluid is described. Measurements were made very close to the plug at Reynolds numbers of 16.5, 47, and 274, and the flow development followed down the tube. The results show that the entrance flow development is dependent on the inlet profile shape and the Reynolds number for Reynolds numbers below 300.The flow development at Reynolds numbers less than 300 was considerably slower than that predicted by the boundary-layer solution of the equations of motion starting with a flat profile.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 124
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 339-350 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: When a porous solid is penetrated by a reactive fluid which changes the pore geometry, the macroscopic properties of that porous material may be greatly changed. A model is proposed in which the matrix is visualized as being a number of short cylindrical pores dispersed randomly throughout the solid. The change in the distribution of these cylindrical pores is then represented by a integrodifferential equation which is solved for two special cases.The evolution of the pore size distribution is determined by the particular way in which the solid-liquid boundary takes place. The case considered here is that of a surface reaction which dissolves the solid thus continuously enlarging the pores. The rate of reaction is calculated theoretically using a laminar flow diffusion model and this growth rate expression is then taken as the basis for numerical calculations relating to the action of dilute hydrochloric acid on limestone.A comparison is made with experimental results and it is found that the model behaves in much the same way as the real system although the observed rate of pore growth was two to three times that predicted by the diffusion model. Several possible explanations for this discrepancy are being tested.An exact solution of the integrodifferential equation for highly retarded reaction rates has been found with the change in permeability being given in terms of the change in porosity. This result will permit a prediction of the stimulation that can be achieved in acidizing oil wells with retarded acids.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 125
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 379-383 
    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 stability of high speed laminar Newtonian jets is studied as a function of ambient air pressure. For Weber numbers less than 5.3 (based on air density) air pressure has no effect on stability. Ambient viscosity, through the effect of shear stresses acting on the jet surface, gives rise to the maximum in the breakup curve. For large Weber numbers ambient pressure effects can alter, and eventually control, the appearance of the maximum.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 126
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 393-400 
    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 gradient technique and Lagrange multiplier are used to obtain the optimum of complex chemical plants. The advantage of this approach is its ability to handle nearly all types of complex stages in a natural way. This approach is used to solve a heterogeneous complex chemical process with recycle. It is shown that although there are many different iteration loops, the convergence rate is fast even with rough starting values and only 0.3 minute is needed to obtain the optimum operating conditions.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 127
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 410-414 
    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 necessary conditions for optimization of a system governed by a nonlinear vector first-order partial differential equation with two (space and time) independent variables, such as governs the unsteady behavior of tubular flow reactors, are derived. Rather general objective functionals and boundary conditions, such as the recycle of unconverted reactant with an appropriate time delay for separation and a free choice of final time, are allowed. A gradient technique in control space is formulated, and it is shown that distinct computational advantages can accrue from the use of the method of characteristics.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 128
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 426-434 
    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 analysis based on the Townsend-Bakewell model of the eddies in the wall regions of turbulent shear flows shows that viscoelastic fluid properties must lead to significant reductions in the rate of production of turbulent energy. This analysis in turn leads to the proper form of the similarity laws for drag reducing fluids, heretofore deduced empirically.Measurements of the axial and radial turbulence intensities for flow through smooth round tubes are reported, as are measurements of the time-averaged velocity profiles and the drag coefficients. These indicate that for solutions exhibiting drag reduction at all Reynolds numbers the flow may be transitional to Reynolds numbers of the order of 105. This transitional flow consists of alternating patches of laminar and turbulent fluid, within each of which the flow characteristics are approximately similar to those of Newtonian fluids. At high Reynolds number conditions with the turbulent field fully developed the velocity profile in the core is flatter under drag-reducing conditions than for turbulent Newtonian fluids, a change dependent on the increased isotropy of the turbulent field of the drag-reducing fluid. These effects appear to be a result of increases in the time scales of the radial fluctuations caused by the fluid properties.Design calculations based upon the present results suggest that in large diameter pipelines, or in boundary layers on large objects, drag reduction may not be attainable under conditions of practical interest until fluids having relaxation times an order of magnitude larger than those presently available, but with comparable viscosity levels, are developed or, alternately, until fluids exhibiting Weissenberg numbers which do not change with deformation rate, can be found.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 129
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 460-460 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 130
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 482-636 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 131
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 483-489 
    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 study concerns rates of evaporation and mass transfer of water vapor from a heated salt solution through a water repellent porous membrane to a cooled water condensate. This transfer is a result of temperature differences and corresponding vapor pressure differences across the membrane. Three groups of experiments were carried out which indicate that the major factor influencing the rates of transfer is diffusion through a stagnant gas in the membrane pores. However, an equation considering film heat transfer coefficients, membrane thermal conductivity, and an empiricial correction based on temperature driving force appears to be necessary for representing all the data. The empirical correction appears to be related to internal condensation and possibly diffusion along surfaces.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 132
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 515-520 
    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 results for the adsorption of the binary gas mixtures oxygen-nitrogen, oxygen-carbon monoxide and nitrogen-carbon monoxide on two synthetic zeolites are reported. In all of these experiments the temperature was -200°F. and the total pressure was 1 atm. Also reported are the isotherms for the three pure gases on the two zeolites at -200°F. The results indicate that these zeolites have a surface selectivity which is independent of any sieving effect based on the size of the adsorbed molecules. It does not appear that the strong separations obtained can be explained in terms of the van der Waals forces which are generally believed to be dominant in physical adsorption. The available methods of predicting binary adsorption data from the pure gas isotherms have been examined.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 133
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 533-547 
    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 effects of a trace quantity of a surface-active agent on creeping flow past a bubble or droplet are investigated. The equations describing mass and momentum transfer are simultaneously solved by a perturbation technique, consistent with the jump mass and momentum balances at the phase interface. The stream function for the velocity distribution is evaluated as an infinite series of spherical harmonics. Galerkin's method, which reduces the partial differential equation of continuity to a set of ordinary differential equations, is used to evaluate the concentration distribution of surfactant.A sample calculation is carried out for relative motion between an air bubble and an infinite body of water which contains a trace of isoamyl alcohol. The relative velocity of the water at an infinite distance from the bubble is found to be highly sensitive to small changes in surfactant concentration from zero, although the bubble varies imperceptibly from a spherical shape.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 134
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 560-564 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Partial removal of dissolved or absorbed solvent from polymers can be accomplished during the process of screw extrusion. This paper shows how two simple transport models based either on an effective diffusivity or on an empirical mass transfer coefficient can be combined with the fluid mechanical equations which describe polymer flow during screw extrusion. In this way, the drying of solvent from a polymer during extrusion can be correlated in terms of the design and operating parameters of the extruder screw and a mass-transfer coefficient or an effective diffusivity. This approach is illustrated employing data obtained by using two extruders of different size and two different solvent-polymer systems. Furthermore, it is pointed out how the results can be used to predict the extent of drying during screw extrusion as well as how modifications in extruder-screw design can permit more extensive drying of polymers during the extrusion process.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 135
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 585-592 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Plexiglas models of rectangular channels were fabricated with various rib shapes to determine the effects of rib and channel geometry on the pressure drop. Pressure drops in twenty-four individual variations of channel geometry were investigated using plexiglas models.From this investigation, an empirical correlation for the pressure drop across the ribbed section of the channel was determined as a function of the linear fluid velocity and the geometric characteristics of the channels. This empirical correlation involves functions of seven geometric parameters of rib pattern and channel geometry.Ribbed section pressure drops for commercial plate heat exchanger channels were predicted using the geometric characteristics of the commercial plates with the empirical correlations developed from the plexiglas channel studies. The total pressure drop for commercial channels was predicted by adding an average entrance and exit pressure drop to the predicted ribbed section pressure drop.The correlations developed in this work allow one to determine the pressure drop in a ribbed rectangular channel from the geometric characteristics of the ribs and the channel in question.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 136
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 612-614 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 137
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 624-624 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 138
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 631-634 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 139
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 643-653 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Shear stress and first normal stress difference data are presented for several polymer solutions undergoing steady shear rates from 1.0 to 100,000 sec.-1. The steady shear response is divided into three regions as a function of increasing shear rate. These are the diffusion controlled linear region, a moderate shear rate region where shear controls the entanglement-disentanglement process, and a high shear rate region where aggregation of polymer molecules occurs. The transitions between the three regions are clearly illustrated by using a group designated as the rotation rate function.A molecular model is derived for the shear controlled region that allows prediction of the first normal stress difference from the viscosity function and one additional constant that depends only on the molecular species. The White-Metzner equation is found to adequately describe the aggregation region at high shear rates.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 140
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 670-679 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Steady state multiplicity in an adiabatic loop reactor was studied in experiments employing the reaction between sodium thiosulfate and hydrogen peroxide in aqueous solution. The steady state characteristics of the loop reactor were predicted by a method which utilized batch reactor data of temperature vs. time directly. The method was based on the assumption of plug flow with negligible axial dispersion and on a single-step chemical kinetic model. Experimental results verify the existence of multiple steady states on ranges of feed flow rates and recycle ratios and demonstrate the capability of the simple model for predicting the qualitative and quantitative features of the reactor steady state.Some observations were made of the effect of large disturbances on the stability of the reactor while operating in a multiple state region. Results for such cases illustrate reactor instability in the sense that a transition to a new steady state takes place provided the disturbance is sufficiently large.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 141
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 707-711 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Red blood cell damage and destruction are important problems in the use of artificial valves, heart-lung machines, and other devices which pump or process blood. An experimental study has been made on the mechanism of cell damage. Damage was defined by three types of observations on blood which had been subjected to trauma: (a) release of hemoglobin from cells (hemolysis), (b) morphological changes observed microscopically, and (c) red cell life span studies in rabbits using a Cr51 tagging technique.Three types of physical forces which might be injurious to red cells were studied; shearing stress (of known, constant magnitudes from a concentric cylinder viscometer), pressure variations (from studies in a static pressure cell), and direct impact of solid surfaces (from studies in a device which simulates the seating action of artificial heart valves).The study shows that high shearing stress may be primarily responsible for mechanical cell damage under certain important circumstances. There is a critical shearing stress above which cell damage increases markedly. Much of the cell damage does not appear as an immediate release of hemoglobin. Many cells undergo morphological changes and exhibit shortened average life span in vivo. The morphological changes due to shearing stress are very similar to the changes observed in patients who have hemolytic anemia associated with artificial valves.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 142
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 733-735 
    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 relatively simple, reliable means is described for measuring particle diffusivity in a particlefluid system in the core of a duct. Particles are injected into the midstream of the duct from a line source positioned normal to the direction of fluid flow. Particle diffusivity is calculated from measurements of the standard deviations of the particle concentration profiles at various downstream distances from the injector. At an air velocity of 10 ft./sec. under room conditions, 1μ oil droplets are found to exhibit a diffusivity of about half that of air alone under the same conditions.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 143
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 750-758 
    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 kinematics of converging velocity fields such as those found in flows from a large duct or reservoir into a small tube are especially simple in the case of viscoelastic materials as they may be approximated by means of a diagonal deformation rate tensor. This result is shown to be valid in the present study in which aqueous polymeric solutions were utilized and is inferred as having been valid under the experimental conditions employed by Bagley in studies of molten polymers. It is suggested that asymptotic approximations based upon the diagonality of the deformation rate tensor may be of general use in analysis of flows of viscoelastic materials, that is, they could represent, potentially, simplifying approximations comparable in utility to the boundary layer approximations employed commonly in the analysis of flows of Newtonian fluids.An interesting prediction of the present analysis is that for flows from a large duct into a small one a plot of isotropic pressure vs. axial position exhibits a minimum near the inlet to the smaller duct. Experimental results are presented in partial support of this unusual behavior. The analysis also suggests that an orfice jet thrust technique for measurement of normal stresses, closely related to recent independent studies by Middleman and by Fabula, may be an indirect but especially simple and sensitive tool for measurement of material properties.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 144
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 785-785 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: No Abstracts.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 145
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969) 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 146
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 809-814 
    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 experimental and analytical study was made to determine how well the material functions, derived from the Spriggs four-constant viscoelastic model, could describe the rheological properties of polymer melts. Viscosity and elasticity of selected polymer melts were experimentally determined in the rotational and oscillatory modes using a Weissenberg Rheogoniometer. The Spriggs model was chosen for study because of its success in describing experimental data for polymer solutions and because of its uniqueness in combining results from molecular theory with results from the theories associated with continuum mechanics. It was found that the model provides a good description of the rheological data for polymer melts and that some of the model parameters depend upon the molecular characteristics of the polymer. Since this model contains a small number of well defined constants, it should be useful in developing dimensionless engineering correlations for the complex flows encountered in processes of industrial importance. Deviations between the theoretical and experimental results are discussed and deficiencies of the model noted.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 147
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 843-853 
    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 is derived for the design of stirred tank reactors for homogeneous reactions. A simple mixing model proposed previously by Curl (4) is used to compute the effects of finite mixing time on complex chemical reactions. It is also shown how the parameters of the model can be obtained by tracer experiments, or estimated theoretically by the assumption of isotropic turbulence. It is shown that in many practical cases the assumption of ideal mixing is a good approximation. However, the effects of imperfect mixing are more likely to be felt in a large reactor than in a pilot plant. Some quantitative examples are discussed. Methods are derived to compute the average outlet concentration for complex systems such as autothermic reactions, polymerization, crystallization, etc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 148
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 885-889 
    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 results on the laminar-nonlaminar transition of aqueous solutions of hydroxyethyl cellulose in axial, isothermal flow in annuli are presented. For each polymer solution the end of the laminar regime is observed to occur at different flow rates at different axial distances from the entrance of the test section. For some polymer solutions in nonlaminar motion, the pressure gradient is not constant over the length of the test section.These data on transition in annuli are compared with predictions made using Hanks' transition criterion where only viscous contributions are considered and where viscous effects are considered and elastic effects accounted for approximately. Predictions where both viscous and elastic properties of the fluids are considered are in fair agreement with experiments. Predictions using purely viscous theory are less accurate than the viscoelastic predictions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 149
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 897-901 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Iterative methods for the solution of the steady state equilibrium stage problem are studied. Equations are first developed for calculating the effect of a change in temperature or flow rate on all energy balances, and then it is shown that these equations can be used in the multiple variable form of the Newton-Raphson correction process to correct either the temperatures or the flow rates when only energy balance errors are used. Similar equations for material balance errors which have been developed previously are then combined with the energy balance equations to provide a method for simultaneous correction of the temperatures and the flow rates. Because first-order interactions between flow rates and temperatures are included the method is applicable to a wide range of equilibrium stage problems. Sample problems are presented, and it is shown that quadratic convergence is obtained for the simultaneous correction process.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 150
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 910-915 
    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 investigation is carried out to determine the onset of convection of a horizontal layer of liquid subject to temperature of T1 and T2 at lower and upper surfaces, respectively. The liquid is assumed to possess a maximum density value at Tmax with Tmax between T1 and T2. The temperature-density relationship within the temperature range |T1  -  T2| can be expressed as ρ = ρmax [1  -  γ1 (T  -  Tmax)2  -  γ2 (T  -  Tmax)3].Both rigid-rigid and rigid-free surface conditions were considered. The critical Rayleigh number defined in Equations (20) and (24) is found to be dependent upon two parameters.Experimental observations on the onset of convection were made and compared with the theoretical results. The experimental work consists of the measurement of the melting rate of a block of ice with melting from both below and above. In all cases, excellent agreement between experimental and theoretical results were obtained.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 151
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 936-939 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: No Abstracts.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 152
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 926-931 
    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 was developed which represented experimental methane P-V-T data over the temperature range of 130 to 625° K. for pressures to 10,000 lb./sq. in. obs. with densities to 0.36 g./cc. For 598 experimental points the mean square percent deviation in the predicted pressures was 0.07% with only 10 points having deviations above 0.2%. The low density limit of the equation predicted second virial coefficients within 1 cc./mole of the accepted values for temperatures above 200° K.The equation was developed by first analyzing isochoric data from the saturation point to the high temperature or pressure limit. An expression was then obtained, reflecting qualitative behavior of the isochores, that reproduced experimental data along each isochore with an average pressure error of 0.02% and a maximum error of 0.08%. This expression had the form P = A + BT + C exp [E (T  -  T0)] + D exp (k - F/T) where k and T0 were normalizing constants and A through F were functions of density. From the density dependence of these parameters a single expression was obtained which fit the entire range of experimental data.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 153
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 939-940 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: No Abstracts.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 154
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 947-947 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: No Abstracts.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 155
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969) 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 156
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 25-28 
    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 success enjoyed by a laminar flow stability parameter that I previously developed as a generalization of the critical Reynolds number of laminar turbulent transition has occasioned considerable interest in the phenomenological theory underlying the parameter. In this paper an analysis of laminar flow stability is presented which leads naturally to the parameter in a much different manner than originally proposed. The stability parameter is seen to represent the coupling ratio between the rate of change of angular momentum of a deforming fluid element and its rate of loss of momentum by frictional drag. At a certain critical value of this coupling ratio, the element becomes unstable to rotational disturbances. If such disturbances are present, the basic nonlinearity of the momentum transfer process guarantees rapid amplification and generation of a turbulent eddy. The consequnces of the theory are examined for two special fixed boundary classes of motion. The physical interpretation of the parameter is compared with conventional interpretations of the Reynolds number and found to be more fundamentally sound. The application of the theory to moving boundary flows, such as the Couette viscometer, is also discussed and an important physical difference is pointed out.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 157
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 39-46 
    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 approximate solution is presented for the countercurrent parallel plate exchanger with laminar flow. With the use of the integral method, the problem is reduced to one of solving a pair of first-order differential equations in a straightforward manner. Comparisons between the results of this work and those obtained from a more elaborate orthogonal expansion technique are found to be excellent.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 158
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 88-93 
    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 rheological properties of foam stabilizers have been measured with an improved canal viscometer that provides absolute values of surface shear viscosity and yield strength. Studies conducted in room air confirmed previous reports of complex non-Newtonian film properties for oil soluble surfactants at the air-oil interface. Both shear and time dependent behavior were observed in which the apparent surface viscosity increased with decreasing rotational speed. Surface viscosities were low at all fresh interfaces but generally increased with the age of the surface over a period of several hours to several days. Experiments conducted in a controlled humidity environment have established that the phenomenon of aging in room air is due to adsorption of moisture from the gas by the surfactant film. Preliminary results indicate that the shear dependency of films in a high humidity environment can be approximated by a Bingham Plastic model which characterize their rheological behavior in terms of a Newtonian surface viscosity and yield value.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 159
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 124-126 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 160
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 132-133 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 161
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 150-151 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 162
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 163
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 28-34 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Simple graphical methods are given for predicting the effectiveness factors of single reactions in particles of various shapes. A collocation procedure is used for small particles, and the known asymptotic solution is used for large particles. Multiple steady states and variable fluid properties can be handled directly. Examples are given for several nonlinear reaction rate laws.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 164
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 177-183 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Entanglement theories for polymer solutions resemble those developed for solid rubbers. These rubberlike theories are extremely successful qualitatively; they give a good indication of the type of response observed experimentally in concentrated solutions. Quantitatively the theories are not so useful; in general they predict constant viscosities in simple shearing motions and ever-increasing tensile stress in steady elongational flow.If it is supposed that the lifetime of the entanglements is limited partly by a maximum allowable strain magnitude, and that the network ruptures locally whenever this magnitude is exceeded, greatly improved quantitative predictions are observed. For polyisobutylene-cetane solutions, where the critical strain magnitude appears to be about 3, excellent prediction of the steady shearing viscosity curve is available starting from the measured dynamical response to small sinusoidal strains and the critical strain magnitude. Normal stress effects are also well represented; in elongational flow the tensile stress shows a slight maximum. It thus appears that the notion of network rupture is useful in guiding the selection of continuum theories for polymer fluid description.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 165
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 239-244 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Thermodynamic properties pertaining to phase equilibria in the binary-fluid hydrate systems, methylene chloride-water and chloroform-water, and the ternary hydrate system, methylene chloride-chloroform-water, were measured. Total vapor pressure data were recorded as a function of temperature over a range of -3 to + 10°C. Quadruple locus measurements of the ternary four-phase equilibrium, L1-L2-H-G, and isobaric studies of the ternary system chloroform-methylene chloride-water, support the existence of a solid solution hydrate between methylene chloride and chloroform. The addition of the nonhydrate former, hexane, to the methylene chloride-water system lowered the isobaric critical decomposition temperature of the hydrate.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 166
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 477-477 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 167
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 322-475 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 168
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 334-338 
    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 finite-difference method is developed for numerical solution of parabolic partial differential equations. This technique is explicit and stable. It is shown that the present method is more accurate and faster, in terms of computer time, than the Crank-Nicholson method. A method of handling nonlinear problems is also presented. Two examples are given to illustrate the present technique. The first problem is a linear diffusion equation. The second problem deals with two simultaneous nonlinear parabolic partial differential equations with Neumann boundary conditions describing the steady state of a packed-bed catalytic reactor with radial mixing.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 169
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 362-366 
    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 rigorous and simple thermodynamic equation relating equilibrium vapor-liquid compositions and the phase enthalpy differences for a binary, isobaric system is extended to multicomponent systems. An analysis is made to indicate the potential applications of computing the latent heat of vaporization directly from the isobaric vapor-liquid equilibrum data and testing the consistency of phase composition and enthalpy data.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 170
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 206-208 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Monocrystals of calcium tartrate tetrahydrate, neodymium-doped calcium tartrate tetrahydrate, and cuprous chloride have been grown by controlled diffusion in silica gel using both metathetical and decomplexation reactions. Conditions for the optimum growth of the crystals are given and it is shown how the pH of the gel, the temperature of its formation, the concentration of the reactants which make up the gel, and the concentration of the reactants which result in the crystal are important in attaining good single crystal products. Crystals have been grown up to 11 mm. on edge in three to four weeks, and in many cases take on a form which, to all outward appearances, seem to have been cut and polished.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 171
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 400-404 
    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 mass transfer on reaction kinetics, within the porous structure of a catalyst, was investigated during the hydrogenation of benzene. The temperature range for a nickel catalyst at atmospheric pressure was 99 to 160°C. The rate equation and the apparent activation energy on a cylindrical catalyst pellet (4.5 mm. in diameter and 5.5 mm. in height) and on the catalyst particles (0.5 to 0.63 mm. in diameter) were evaluated.The effect of internal diffusion on the dependence of the reaction rate, on the temperature, and on the partial pressures of benzene and hydrogen was satisfactorily explained by means of theoretical relations. The values of the effective diffusion coefficient of benzene were compared by calculating the kinetic data and temperature difference in the cylindrical pellet.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 172
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 419-425 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Mass transfer to spheres suspended in an agitated liquid has been studied both experimentally and theoretically. Finite-difference solutions are obtained for mass transfer from a sphere to a fluid flowing past it in steady viscous flow. The effects of a transpiration velocity at the surface of the sphere and of a continuously changing sphere diameter are included. A normalized presentation of these effects is quite insensitive to the bulk flow Peclet number. When these theoretical corrections for transpiring and shrinking spheres are applied to the mass transfer data for ice spheres that are melting in an agitated brine bath, the corrected mass transfer coefficients are brought into agreement with a generalized correlation published elsewhere. This agreement suggests that the theoretical results apply, with reasonable accuracy, to a shrinking and transpiring sphere that is suspended in a turbulent liquid.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 173
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 463-465 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 174
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 469-470 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 175
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 471-472 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 176
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 504-507 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Numerical solutions of the equations of motion and energy are presented in the form of pressure-loss, flow-rate relationships for the laminar, nonisothermal flow of Newtonian and non-Newtonian fluids being heated and cooled in tubes at constant wall temperature. The flow properties are represented by a temperature-dependent form of the power law equation. The numerical results are shown to be in good agreement with experimental data for a wide range of fluid properties and flow conditions.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 177
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 581-585 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Heat transfer and pressure-drop studies were made on a series of electrically heated tubes containing full-diameter, full-length twisted tapes. The A nickel tubes had a nominal inside diameter of 0.4 in. (10.1 mm.) and a heated length of 12 in. (30.5 mm.). Nitrogen at 200 lb./sq.in. gauge (14.6 atm.) was the working fluid, and the tests covered the Reynolds number range from 20,000 to 200,000. Twist ratios, defined as the ratio of the tube length per 180 deg. twist to the tube diameter, were varied from 2.5 to 14. The effect of tube wall-to-gas temperature ratio was studied for values of up to 1.8 and the heat flux was varied from 104 to 105 B.t.u./hr. · sq.ft. (3 × 104 to 3 × 105 w./sq.m.).The results were compared with the results of previous heat transfer and pressure-drop studies and were generally found to be in good agreement. An empirical correlation was developed for the heat transfer results that accounts for the effects of twist ratio, wall-to-gas temperature ratio, and tube length and includes most of the previous single-phase results.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 178
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 575-580 
    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 simple means for predicting composition distributions in copolymers is used to illustrate the strong influence of segregation effects in the reactor. A recycle loop reactor can be used to produce uniform copolymers by narrowing the macroscopic composition distribution, but there is a limiting microscopic distribution which results from probabilistic effects.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 179
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 454-459 
    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 onset of rotational flow instability was determined experimentally for dilute solutions of six polymers. In general, the onset of secondary motions occurred later than for a Newtonian liquid of equal apparent viscosity, although, depending upon geometric ratios, some instabilities occurred earlier than in the Newtonian liquid. The stability theory of Ginn and Denn was used to calculate viscometric normal stress functions for ten solutions, with excellent agreement obtained with rheogoniometric measurements of the primary normal stress measurements in all but three cases. Torque measurements of the laminar secondary motion following instability showed some frictional drags significantly less than those observed in Newtonian liquids, a phenomenon analogous to the turbulent drag reduction observed previously in dilute polymer solutions.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 180
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 642-793 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: No Abstracts.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 181
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 660-665 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Manning, Wolf, and Keairns' model for continuous flow-stirred tank reactors has been extended to include adiabatic as well as isothermal operation. The adiabatic, steady state yield of a continuous flow-stirred tank reactor was measured experimentally using the second-order, homogeneous, exothermic reaction between sodium thiosulfate and hydrogen peroxide. Model predictions of overall tank yield agreed closely with the data, thus verifying the applicability of this model to explain the effects of operating variables such as impeller size, impeller type, agitator speed, feed location, feed concentration, and flow rates.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 182
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 680-685 
    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 mechanism of solid state polycondensation has been subjected to a fundamental analysis. Equations were formulated for combined diffusion and chemical reaction for two separate situations. One was for solid state polycondensation in polymer flakes or chips. The other dealt with polymer powders. The resultant solutions related molecular weight changes to rate functions. A technique for deriving the rate functions from experimental data is described.Solid state polycondensations were then studied for nylon 66, nylon 6-10, and polyethylene terephthalate. These data which ranged from 120 to 200°C. were tested with various mechanisms. The most appropriate one was found to be that developed in the present work. Chemical reaction was found to be the rate controlling step in solid state polycondensation in nylon 66, polyethylene terephthalate, powders of nylon 6-10 and larger particles of nylon 6-10 at and above 160°C. Diffusion of byproduct through the solid was the rate controlling step for larger particles of nylon 6-10 at temperatures below 160°C. Thermograms of nylon 6-10 indicated morphological changes which possibly influenced the behavior of the larger nylon 6-10 particles. The Arrhenius relation was fitted to the situations where chemical reaction controlled.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 183
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 686-689 
    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 circular films, formed over a flat water surface during the dissolving (influenced by surface forces) of isobutanol, is examined by performing film thickness and surface velocity measurements. The thicknesses were obtained by light absorption determinations, and the velocities by a stroboscopic method. The film profiles and the dynamic wetting angles obtained differ markedly from those corresponding to a static lens. This is explained by considering the equilibrium between dynamic surface tensions instead of that between static surface tensions.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 184
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 837-842 
    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 phenomenon of reversing axial flow in swirling incompressible flow through a tube has been investigated experimentally. The study was carried out in a 2 in. I.D. test section of plexiglass tubing 10 ft. long. The swirl was introduced by injection of the total fluid stream through two symmetric tangential inlets perpendicular to the tube. Measurements have been made with specially constructed stagnation and static pressure probes.Velocity and pressure profiles obtained for tests conducted at four Reynold's Numbers in one fixed geometrical configuration are presented and discussed in general terms. Swirl decay rate is characterized in a plot of weighted tangential velocity/inlet velocity ratio versus distance along the test section from the inlets. A model presented by a previous investigator to explain the flow reversal phenomenon is discussed in the light of present work. Finally the data is used in an order of magnitude analysis to reduce the turbulent Navier-Stokes equation describing the flow to simpler (though still indeterminate) form.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 185
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 872-884 
    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 natural convection on polarization and flow patterns in liquid phase convective diffusion in a vertical duct with semipermeable membrane walls has been investigated theoretically. It is found that at low flow rates, gravitational fields can play a significant role in distorting the velocity profiles and thereby they affect the transition from laminar to turbulent flow. Natural convection also significantly affects mass transfer rates and therefore the extent of polarization at low flow rates. Results are presented for both momentum and mass transfer in upward and downward flows for different wall Peclet numbers. The hydrodynamic stability of the system also has been investigated and critical values of the buoyancy parameters are reported. Also, these results enable one to estimate when natural convection may create errors in membrane testing systems.The analysis and results are of practical interest in reverse osmosis and other membrane separation processes. The more productive the system, the more likely it will be that buoyancy effects are important.
    Additional Material: 21 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 186
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 890-897 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Data are presented for wall temperatures and heat transfer coefficients for solid-vapor mixtures of parahydrogen and nitrogen flowing in an electrically heated straight tube of length 40 times its diameter. These are interpreted by the application of flat plate, constant property boundary-layer theory to models in which the solid particle geometrical distribution takes on simple limiting forms. The observed enhancement of the heat transfer coefficient over that for gas alone traveling at the same velocity is qualitatively predicted as a function of a dimensionless heat flux, the Sterman parameter qw/ρvUλ.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 187
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 902-910 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Positive feedback control systems sometimes can be used to make stable chemical reactors generate periodic outputs. For one set of system parameters the time average conversion obtained from the oscillating reactor was approximately 20% higher than the economic optimum steady state value; for another case the time average operating cost was approximately 5% lower than that corresponding to the optimum steady state design. A general method for predicting when an improvement can be obtained is presented.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 188
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 932-933 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: No Abstracts.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 189
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 950-951 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: No Abstracts.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 190
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 942-947 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: No Abstracts.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 191
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 51-56 
    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 knowledge of liquid-film flow rates is important for design purposes when accurate predictions are required of the conditions under which dryout heat flux occurs in nuclear reactors and boilers. Liquid-film flow rates were measured for a steam-water mixture in cocurrent, upward annular flow in a tube at a pressure of 1,000 lb./sq.in.abs. Sinters located at the test section exit were used to extract the liquid film after the method of the Harwell group. Sinter lengths of 2, 1, and 1/2 in. were employed to investigate the effect of length on the extracted liquid flow rates. The test section was a stainless steel pipe of inside diameter 0.493 in., approximately 200 diam. in length. The total mass flux ranged from 0.2 to 0.7 × 106 lb.m/hr.sq.ft. and the quality varied from 0.3 to 0.92.The experimental film flow rates were found to increase with decreasing quality. In the range of parameters investigated, the curves of film flow rate at constant quality vs. mass flux showed a maximum at a fixed value of steam velocity. At the same total mass flux and quality the film flow from the 1/2 in. sinter was lowest, suggesting that the crests of high amplitude roll waves overshot the sinter. Film flow rates were consistently higher than the theoretical predictions using Levy/s model. About one-third of the measured flow rates were twice as high as predicted.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 192
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 73-80 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Data are presented on the solubility in and permeation through polyolefin films of a number of gases and liquids. The permeation rates are found to be dependent on the type of film, the concentration and the temperature. A classical diffusion model explains the permeation mechanism and other relations serve to correlate the data.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 193
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 141-144 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 194
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 151-153 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 195
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 196
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 164-170 
    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 theoretical study has been made on the effect of pulsations in the flow field on interphase mass transfer. The phenomenon is of interest in studies of the cardiovascular system as well as in traditional engineering applications. The physical situation studied corresponds to fully developed flow in a long conduit with a periodic pressure gradient. The mass transfer problem was solved analytically for low amplitude pulsations for the two limiting cases of very small and very large frequencies. In addition, several numerical solutions were developed in the intermediate region where the asymptotic solutions are least accurate. The solutions taken together give a good quantitative overall view of the phenomenon.One of the most interesting and unexpected results is that at very low frequencies it is possible for a pulsatile flow to yield a lower interphase mass flux than a steady Poiseuille flow with the same velocity.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 197
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Calculations of the molar heat and entropy of adsorption for pure methane and pure ethane on silica gel at 25°C. show the heterogeneity of the adsorbent when plotted as functions of the spreading pressure. Plots are given for the activity coefficient of methane and ethane in the adsorbed phase based on experimental data for the entire range of compositions at 25°C. up to a maximum pressure of 1,400 lb./sq.in.abs. Similar results were obtained at 5, 15, and 35°C. The activity coefficients deviate from unity at intermediate compositions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 198
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 235-239 
    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 nonuniform distribution of vapor across a distillation plate causes a reduction in the Murphree plate efficiency. The magnitude of the reduction has been evaluated and the maximum effect occurs when the liquid mixing is intermediate between the perfectly mixed and the plug flow cases.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 199
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 269-271 
    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 free volume equation for liquid viscosities is generalized to multicomponent mixtures. No experimental mixture data are needed in order to use the correlation. Calculated viscosities for liquid mixtures composed of molecules which approximately obey the Lennard-Jones 6, 12 potential law show very good agreement with experimental data for eight binary systems.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 200
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 15 (1969), S. 289-290 
    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
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...