摘要:

ABSTRACTAn optical sensor was devised to observe cleaning kinetics of heat exchange surfaces fouled by milk and to study the influence of some parameters on them.The sensor works by sensing the attenuation of incident light by the suspension of deposits which are removed by the cleaning solution.The cleaning is carried out without recycling the cleaning solution. The on‐line collected numerical data are converted into concentration values by the use of an empirical correlation based on samples of freeze dried deposits diluted with soda solutions. The cleaning kinetics and the weight of removed fouled material are computed for each experiment by integrating the concentration versus time curve.Over 20 experiments, carried out on a plate milk pasteurizer have established the validity of the method. The kinetics are interpreted as initially zero order, but first order at the end of the proces

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1982.tb00267.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTTo be able to minimize losses in terms of quantity and quality during storage time, investigations to determine the relations between respiration of shelled corn and moisture content and temperature were carried out. The main part of this paper cornsists of a description of a quick method to determine the amount of carbon dioxide produced and discusses the results evaluated by using this method. These results were checked by comparing them with respiration data evaluated with 0.6 m3bins which are also briefly discussed.

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1982.tb00268.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTShear stress development at inception of a constant shear rate was studied for marshmallow cream, peanut butter, squeeze margarine, tub margarine, whipped butter, whipped cream cheese and whipped dessert topping using the cone and plate geometry of the Rheometrics Mechanical Spectrometer. For most foods studied transient shear stresses showed increasing shear stress oversoots with increasing shear rate. At the highest shear rate of 100 s−1, transient stresses were as large as 425% of the steady state shear stresses, with the actual magnitude of overshoot depending on the particular food investigated.The Bird‐Leider equation was chosen to model this time dependent flow behavior by incorporating both steady viscous and elastic properties of the foods. By assuming that the viscosity function and primary normal stress coefficient followed power‐law behavior, and constructing a time constant from the calculated parameters, the Bird‐Leider model provided a good prediction of maximum and steady state stresses as well as the time at which they occur, but only a crude prediction of shear stress decay. The model supplied two more empirical constants “a” and “b” where “a” can be regarded as a pseudo‐elastic modulus. Variation in “a” with shear rate shows that all materials studied a

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1982.tb00269.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

摘要:

ABSTRACTA decision problem associated with the production of the same goods under several labels is anticipating how much to produce under each label. In some settings a portion of the goods is left unlabeled so that subsequent excess demand can be filled by labeling these goods held in “bright storage”. This adds another decision variable to the problem and introduces some new alternatives. Attached to these alternatives facing the decision maker are several different kinds of costs depending upon the nature of the errors made in forecasting the demand for each of the labels. These costs, when associated with discrete probability distributions for the demand variables, lead to an optimization problem with nonnegative variables with objective of minimizing the decision maker's expected cost. Minor restrictions on the costs make this objective function, convex. By introducing new variables the entire problem can be reformulated as a linear program. If the demand variables can take only integer values, then there is an integer, optimal solution to the bright storage prob

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1982.tb00270.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY

ISSN:0145-8876    

DOI:10.1111/j.1745-4530.1982.tb00271.x

出版商:Blackwell Publishing Ltd    

年代:1982

数据来源: WILEY