ISSN:0008-4034    

DOI:10.1002/cjce.5450500201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

ISSN:0008-4034    

DOI:10.1002/cjce.5450500202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractFor autocatalytic reactions such as those associated with many biochemical processes, the rate of a reaction is influenced by the concentrations of some of the products as well as those of the reactants. By use of the so‐called diffusion (axial dispersion) model in conjunction with the Monod growth kinetics, it is shown that partial (incomplete) fluid mixing is often desirable for this class of reactions. Under sterile feed conditions, the optimal Peclet number appears to range between 0 and 2 with the exact value depending on the values of the kinetic constants and initial substrate concentration. By varying this single parameter, the performances of such reactors under various degrees of fluid mixing can be readily investigated using the axial dispersion model. The optimal design may be physically realized by the use of a tower fermentor with controlled axial dispersio

ISSN:0008-4034    

DOI:10.1002/cjce.5450500203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractThe effect of intraparticle diffusion in artificial membranes on the kinetic behavior of immobilized enzymes has been considered theoretically in terms of an effectiveness factor. When the immobilized enxymes obey a Michaelis‐Menten relationship, an approximate equation is proposed for the effectiveness factor. For a substrate inhibited enzymatic reaction, the effectiveness factor may exceed unity and display multiple steady‐state behavior. Thus, the over‐all rate of reaction in the artificial membrane is faster in this case than that when the substrate concentration in the interior is at the same as that at the exterior surface. In the case of a product inhibited enzymatic reaction, the effectiveness factor is always less than that which corresponds to a Michaelis‐Menten relat

ISSN:0008-4034    

DOI:10.1002/cjce.5450500204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractThe first stage of a study of the extrusion of starch‐based materials is described. The chemical and physical changes which occur in the extrusion of a corn starch‐water system relative to fifteen extruder variables have been investigated.A mathematical model of the extruder has been obtained from analysis of the data. The important variables were found to be moisture, barrel and die temperatures, screw speed and screw geometry. A strong interaction between moisture and barrel temperature was found to occur. These variables in the model account for 90.5% of the variance in the data obtained. The effects of the variables on the gelatinisation and shearing mechanical degradation of starch are discus

ISSN:0008-4034    

DOI:10.1002/cjce.5450500205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractCarbon mass balance techniques are applied to biological oxidation systems. Equations are developed for rates of substrate utilization and carbon dioxide production. Carbon balances for suspended cellular material are given. The total organic carbon analyzer was used for carbon balance determinations and illustrative examples taken from studies of biological oxidation toxicity to cupric ion. Problems with the use of the analyzer are discussed. Within the pH range 6–9, no effect of pH on organic carbon analysis was observed. Efficiency of substrate utilization and concentration of suspended solids in an activated sludge plant are both determined from carbon analyses. Suspended solids were also determined by a direct weighing procedur

ISSN:0008-4034    

DOI:10.1002/cjce.5450500206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractThe preliminary design steps for a secondary sewage treatment process are discussed in a case study format. A tubular contactor with an oxygenator and reactor section is proposed as an alternate design to the conventional open tank process.

ISSN:0008-4034    

DOI:10.1002/cjce.5450500207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractSolutions of 20, 50, 100 and 150 mg/l of phenol and o‐cresol, and of 10, 20 and 50 mg/l of p‐xylenol were aerated in laboratory tank with the intensity in the range from 6 to 30 m3of air per m3per hr. The presence of phenol and o‐cresol in water enhanced the aeration kinetics with effects growing with aeration intensity. The presence of p‐xylenol caused increases or decreases in oxygen transfer rates, depending on the concentration of the substance and intensity of aeration. Only influence of phenol seemed not to be concentration de

ISSN:0008-4034    

DOI:10.1002/cjce.5450500208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractActivation analysis is a highly sensitive and specific technique for the detection of trace heavy metal pollutants in environmental materials. Comparison of natural “baseline” levels with elevated levels provides direct evidence of contamination. Neutron activation analysis (NAA) is used in this study to determine arsenic, zinc, cadmium, and mercury. Photo‐nuclear activation analysis (PNAA) is used to determine lead in soils. Holland Marsh, a market‐gardening area north of Toronto, has been studied as various herbicides and fungicides have been used there. The analyses of soil and vegetation samples, and of human head hair collected from residents are r

ISSN:0008-4034    

DOI:10.1002/cjce.5450500209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY

摘要:

AbstractTheory for calculating the mean velocities of the drops and of the film in gas‐liquid cocurrent annular flow by use of tracer pulse techniques has been developed. It is shown that the interaction between the film and the drops affects the mean residence times in each, and is much greater in its effect than is axial dispersion in the film or in the core.The theory also describes a relatively simple means of determining the mean amounts of droplet entrainment and liquid interchange between droplets and film from measurements made with continuous tracer injection. Knowledge of the entrainment and the mean velocities of film and drops is essential in determining the extent of interaction between the liquid film and the entrained liquid flo

ISSN:0008-4034    

DOI:10.1002/cjce.5450500210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1972

数据来源: WILEY