Bi-objective min-flow problem with capacity and flow constraints

A network flow algorithm for a bi-criteria version of the manpower scheduling and resource allocation problem is developed. In such a study it is desired to find the ‘minimum’ total ‘flow’ through the network, where ‘flow’ is represented by a two-component cost vector and ‘minimum’ is interpreted in the sense of a vector-minimum. Thus, a set of non-dominated solutions is obtained. The method efficiently generates both individual (criterion) optima and bi-criteria solutions in a single pass. A simple example is presented.     

Heat conduction and thermal stabilization in YBCO tape

Yttrium barium copper oxide (YBCO) coated conductors are widely used in the conduction-cooled superconducting magnets with rapid development in refrigeration technologies at present. ‘Quench’ is a state that refers to the irreversible and uncontrolled superconductor to resistive transitions in the superconductor. The propagation of ‘quench’ or ‘normal zone’ has different characteristics in these high temperature superconductors (HTS) compared to low temperature superconductors. The superconductor to normal index, known as ‘n’ is much flatter in HTS. The hot spot emerging in local region due to quench and non-uniform critical current may cause permanent damage to whole HTS tape and hence the magnet winding pack. Thus it is necessary to determine the temperature profile along the length of HTS tape under a given energy (joule heating) such that propagation of the hot spot developed locally can be prevented early. In this study, a one dimensional, time dependent heat diffusion equation with appropriate boundary conditions are used to describe the consequences of the normal zone propagation resulting in the temperature diffusion in a HTS tape. The results demonstrate the necessity of adequate cooling of the edges of the flat HTS tapes to prevent irreversible normal zone transitions.     

Feed Moisture Effects on Functional Properties, Trypsin Inhibitor and Hemagglutinating Activities of Extruded Bean High Starch Fractions

High starch fractions (HSF) of navy, pinto and garbanzo beans were extruded with different moisture contents using a Wenger X-5 extruder. Increasing moisture content resulted in increased expansion index for navy and garbanzo beans and a decrease for pinto bean. The highest water absorption index was obtained for navy bean HSF at moisture 27%, for pinto 30% and for garbanzo 26%. For all beans, water solubility index decreased with increasing moisture. Color of extrudates also was affected by moisture. The extrusion process reduced trypsin inhibitor activity by about 70–85%, the level of decrease determined by moisture content of starting material and temperature. Extrusion temperatures of 121, 132 and 150°C inactivated hemagglutinating activity of navy, pinto and garbanzo beans.     

Enzyme—Pretreatment of Pinto Bean High Protein Fraction and Time of Blending Corn Meal Affects Extrudate Properties

High protein fraction of pinto bean, treated with papain and cellulose enzymes (Solvay Enzymes Inc.), was blended with corn meal (30%) and extruded at 120°C. Changes in expansion, texture, color, pH, in vitro protein digestibility, reducing sugars and functional properties of extmdates were recorded. Changes depended on type of enzymes and time of corn incorporation (before or after enzymatic pretreatment). The best texture of the extrudates was obtained using a cellulase enzyme. Papain affected some functional properties such as NSI and WSI. The best improvement in in vitro protein digestibility and reducing sugars was found with a cellulase treatment. Protein and fiber could be modified to improve physicochemical and functional properties of extrudates.