Physical Properties of Dietary Fiber and Binding of Mutagens

Some characteristics of dietary fiber that may contribute to the epidemiology of intestinal disease including colon cancer were investigated. Soft white wheat bran (AACC), hard red wheat bran (AACC), corn bran, and cellulose were tested for their ion exchange capacity and ability to bind mutagens (benzopyrene, 2-amino anthracene (2-AA), and mutagens extracted from fried ground beef. The wheat brans had the highest ion exchange capacity and were effective in binding the 2-AA. Benzopyrene and the fried ground beef mutagens were not effectively bound by fibers. The results suggest that dietary fibers may modify the levels of some intestinal mutagens, but may be ineffective for fried ground beef mutagens.     

Selective laser melting of Fe-Ni-Cr layer on AISI H 13 tool steel

An attempt to fabricate Fe-Ni-Cr coating on AISI H13 tool steel was performed with selective laser melting. Fe-Ni-Cr coating was produced by experimental facilities consisting of a 200 W fiber laser which can be focused to 80 μm and atmospheric chamber which can control atmospheric pressure with N₂ or Ar. Coating layer was fabricated with various process parameters such as laser power, scan rate and fill spacing. Surface quality and coating thickness were measured and analyzed. Three different surface patterns, such as type I, type II and type III, are shown with various test conditions and smooth regular pattern is obtained under the conditions as 10 μm of fill spacing, 50–350 mm/s of scan rate and 40 μm of fill spacing, 10–150 mm/s of scan rate. The maximum coating thickness is increased with power elevation or scan rate drop, and average thickness of 10 μm fill spacing is lower than that of 40 μm fill spacing.     

Experimental investigation of friction coefficient in tube hydroforming

The friction coefficient between tube and die in guide zone of tube hydroforming was obtained. In hydroforming, the tube is expanded by an internal pressure against the tool wall. By pushing the tube through tool, a friction force at the contact surface between the tube and the tool occurs. In guiding zone, the friction coefficients between tube and die can be estimated from the measured axial feeding forces. In expansion zone, the friction coefficients between tube and die can be evaluated from the measured geometries of expanded tubes and FE analysis.     

Controllable production rates in a family production context

We consider a single facility dedicated to the production of a family of items where the policy used is to cycle production through the items every T units of time. This is known as the Common Cycle or Rotation Schedule and is a special case of the Economic Lot Scheduling Problem (ELSP). We consider the case in which the production rates can be reduced from known maximum rates. Moreover, we assume that production rates can be changed during the production runs. We optimally partition the items into those with high and low holding costs. The former are initially produced to meet demand while the latter are always produced at their maximum rates. Numerical examples indicate savings almost twice as large as those reported in the literature.     

Determination of optimum unit load size of the AGV in an electronics assembly production system

This paper deals with the problem of determining an optimum unit load size of automated guided vehicle (AGV) in an electronics assembly production line. It is assumed that an AGV delivers assembly parts to each workstation from a miniload automated storage/retrieval system and a conveyor line transports subassemblies between workstations. Two types of operating policies for the AGV system are proposed. For each policy, a nonlinear mathematical model is formulated. Based on the characteristics of the objective function and feasible region, a solution algorithm is developed, which finds an optimum unit load size. To illustrate the models, problems are chosen and solved.     

Multiproduct economic lot size models with investment costs for setup reduction and quality improvement: review and extensions

There is a rapidly growing literature on modelling the effects of investment strategies to controlgivens such as setup time, setup cost, quality level. Recently, Hwang et al. (1993) studied the multiproduct economic lot size models in which setup reduction and quality improvement can be achieved with one-time initial investment. The aim here is to review and extend their work. First, we point out that their algorithms can produce irrelevant solutions and clarify the cause of the problem. Second, we provide a complete formulation and analyse for the general investment functions using the Lagrangian method. The algorithm to find an optimal solution is provided and an example problem is solved to illustrate the algorithm.     

Comments on ‘ On decentralized feedback stabilization of large-scale interconnected systems ’

A proposition presented by Mahalanabis and Singh, which asserts that, the stability of each aggregated subsystem implies the stability of a large scale system, is shown to be erroneous.     

EFFECTS OF PROCESSING TIME AND TEMPERATURE ON THE QUALITY COMPONENTS OF CAMPBELL GRAPE JUICE

Campbell grape juice was processed at different temperatures (60, 70, 80 and 90C) and different times (30, 45 and 60 min), and evaluated for quality components and sensorial properties. The grapes were crushed, added with enzyme, heated, and pressed; then the juice was cold stabilized, filtered and pasteurized. The samples showed an increase in pH and a decrease in titratable acidity. Sugar/acid ratio and total soluble solids increased until 80C then decreased when 90C was reached. A slight increase in L* and b* values and a decrease in a* color values were also shown. Significant differences were mostly observed between processing temperatures than between processing times. Increasing processing temperature enhances the total phenolics, total anthocyanin and total flavonoid contents, and % radical scavenging activity of the juice until 80C but declined when the temperature reached 90C. Sensory evaluation showed that the preferred time–temperature combination for processing Campbell juice is between 70 and 80C for 30–45 min.

PRACTICAL APPLICATIONS

Campbell Early ( V. labrusca B.) is one of the major table grapes in Korea and overproduction of this grape variety in Korean market calls for an alternative product in which excess grapes can be utilized. This study is focused on the determination of the effects of processing time and temperature on the quality components of Campbell grape juice. The results can be a guide to have a processing method that can be used in producing Campbell grape juice with good sensory properties and high bioactive compounds     

Effect of W/C ratio and cover thickness on polarization characteristics of embedded steel in mortar

The effects of cover thickness and W/C (water-to-cement) ratio on polarization properties of embedded steel bar were investigated with electrochemical methods. Corrosion potentials shift to the noble direction with increasing the cover thickness. In addition, when the cover thickness increasingly becomes thinner and thinner, effect of the W/C ratio on variation of corrosion potential increases as well. Impedance value at 100 kHz indicating the resistance of cover thickness increases with the decrement of W/C ratio as well as the increment of cover thickness. However, in the case of W/C ratio at 0.6, impedance at 10 mHz shows the relatively larger value than that at W/C ratio of 0.4 or 0.5 in the range of cover thickness from 4 to 8 cm, which is probably expected that oxide film built up on the surface of steel bar due to strong alkali environment by hydration reaction with increasing W/C ratio is performed as the resistance polarization. It is also observed that liquid junction potential tends to increase with decreasing W/C ratio.