EMULSION COATING TO EXTEND POSTHARVEST LIFE OF MANGO (MANGIFERA INDICA CV. MANILA)

A coating emulsion was prepared using maltodextrins, carboxymethylcellulose, propileneglycol and a mixture of s orbit an fatty acid esters with an HLB of 6. The emulsion was sprayed on fully mature, unripened manila mangoes, which were the stored at 15 and 25C and 80–85% R.H. At 25C it was observed that rate CO² production increased and lost in control fruits after 12 days of storage. Coated mangoes kept their rate CO² production and suffered only 8% weight loss after 21 days of storage. After storage, the coating was washed out and fruits were allowed to ripen naturally, which occurred in 3–4 days. The results obtained from this study indicate that application of the hydrophobic coating extended the postharvest storage of mangoes for at least 20 days more than uncoated fruits.     

Nitrogen-Nitride Equilibria in Molten Uranium-Thorium-Tin Alloys

Work has been done on the molten ternary system U-Th-Sn to provide a selective nitriding separation scheme. The nitride formation reaction has been studied as a function of temperature (1490° to 1700°C) and weight percent of U/Th in Sn, using a Sievert's-type apparatus. Nitride formation has been demonstrated in a U-Th-Gd system.     

Cellular/dendritic transition,dendritic growth and microhardness in directionally solidified monophasic Sn-2%Sb alloy

Horizontal directional solidification experiments were carried out with a monophasic Sn-2%Sb (mass fraction) alloy to analyze the influence of solidification thermal parameters on the morphology and length scale of the microstructure. Continuous temperature measurements were made during solidification at different positions along the length of the casting and these temperature data were used to determine solidification thermal parameters, including the growth rate (V_L) and the cooling rate (T_R). High cooling rate cells and dendrites are shown to characterize the microstructure in different regions of the casting, with a reverse dendrite-to-cell transition occurring for T_R>5.0 K/s. Cellular (l_c) and primary dendrite arm spacings (l₁) are determined along the length of the directionally-solidified casting. Experimental growth laws relating l_c and l₁ to V_L and T_R are proposed, and a comparative analysis with results from a vertical upward directional solidification experiment is carried out. The influence of morphology and length scale of the microstructure on microhardness is also analyzed.     

Mass transfer during osmotic dehydration of pineapple rings

The effect of temperature (30, 40 and 50°C) and sucrose concentration (50, 60 and 70°Brix) on the osmotic dehydration of commercial size pineapple rings were studied, at an initial ratio of 1:4 fruit:sucrose solution. The rate of water loss in the fruit varied with both osmotic solution concentration and temperature. A proposed model based on Crank's equation was fitted to the experimental data.     

A FUZZY ALGORITHMIC APPROACH TO THE CONSTRUCTION OF COMPOSITE INDICES: AN APPLICATION TO A FUNCTIONAL LIMITATION INDEX

This paper presents a fuzzy algorithmic approach to the construction of composite indices. The method uses a fuzzy analytic translation of a linguistic definition of the composite index, where the definition involves more primary concepts for which scales already exist. An application to the construction of a functional limitation index is presented. Comparisons between the fuzzy algorithmic approach and a more standard, tabular approach are also shown. The results suggest that the fuzzy algorithmic approach yields essentially the same index with less effort and some conceptual advantages.     

Local multi-valued logics in modular expert systems

Abstract

Abstract. In this paper we describe an approach to the problem of dealing with uncertainty by means of finite multi-valued logics in modular expert systems, and the results obtained. The modularity of the systems allows us to address two main characteristics of human problem-solving: the adaptation of general knowledge to particular problems and the dependency of the management of uncertainty on the different subtasks being implemented in the modules of the system, i.e. different modules can have different local multiple-valued logics as part of their local deductive mechanisms. Although the results obtained are general, we use, throughout the paper, examples of a medical expert system that has been designed using a modular language called MILORD-II, that implements them showing the practical interest of the theoretical concepts involved.     

New management policies to improve the effectiveness of multi-station service organizations

Clark et al ( 1992)reported on the use of a computer simulation model to show that significant reduction in customer ‘ waiting time’ could be achieved by new management policies for multi-station service organizations. They modelled a multi-phase queuing structure and showed reductions in the system variable ‘ time in system’ when servers were pooled at the first reception desk, rather than having single servers at multiple desks to provide service. Their model also demonstrated a greater savings in system transit time when the servers moved with the customers through subsequent tasks (multi-phase systems) This paper uses classical queuing theory to evaluate these results. We conclude that Clark et al' s findings can be supported through use of the classical waiting line formulas.     

Microcomputer-Aided Evaluation of Earthquake-Induced Permanent Slope Displacements

Ageotechnical engineering microcomputer program has been developed for the determination of permanent slope displacements resulting from earthquake shaking. The Newmark procedure, in which accelerations in excess of yield accelerations are double integrated to obtain displacements, has been incorporated into the program DISPLMT. Several user options are available for describing the yield acceleration function, including variation with time and variation with displacement. Screen graphics are available which allow the user to observe the down slope movements of the Newmark sliding block as they increase with time during the simulated earthquake. DISPLMT has been used to calculate the permanent movements of an earth dam using acceleration-time histories and soil shear stresses determined from a separate analysis. Modification to the conventional Newmark procedure, by introduction of a "slip layer," has been made in the analysis of a dam. Permanent slope displacements can be analyzed using the recommended procedure, which involves fairly simple computations that can be performed in a reasonable period of time with the exclusive use of microcomputers.     

Laboratory and Pilot Scale Recovery of Protein from Mechanically Separated Chicken Residue

Bone residue resulting from mechanical deboning of chicken backs and necks was subjected to alkali extraction followed by acid precipstation to recover food grade protein. A laboratory study of effects of varying die size in the grinding of the starting material, of extraction temperature, and of g-force during centrifugation on composition of process fractions was conducted. Grinding increased ash content, higher temperature reduced fat content, and increasing centrifugal force decreased ash content, of the final products. Effects of grinding, extraction temperature, and centrifugal type were also studied on a pilot scale. Final protein product yield was higher at a 22°C than at a 3–7°C extraction temperature, and less fat was incorporated using a basket centrifuge than with a horizontal decanter centrifuge.     

GROWTH OF EUROTIUM CHEVALIERI IN MILK JAM: INFLUENCE OF PH, POTASSIUM SORBATE AND WATER ACTIVITY

Milk jam (dulce de leche) is a typical Argentine sweet spread prepared by milk evaporation to about 70% w/w total solids at atmospheric pressure with added sucrose, glucose and vanillin. Growth of xerophilic molds represents a severe problem in this type of intermediate moisture product. This study evaluated the growth response of Eurotium chevalieri in milk jam with different potassium sorbate (KS) concentrations (0, 500, 1,000, 1,500 and 2,000 ppm) at selected water activity (a_w) values (?0.80 and 0.85) and two pH levels (?5.5 and 6.0) stored at room temperature (25C) for 90 days. Growth curves were characterized by the modified Gompertz model, and the effect of the independent variables on the estimated parameters (maximum specific growth rate, v_m, and lag time, λ) was analyzed through polynomial equations. Growth of E. chevalieri was prevented for at least 90 days when the addition of 1,000 ppm KS was combined with a decrease in a_w to 0.80 and ph 5.5. The boundary between growth and nongrowth of E. chevalieri as a function of a_w, pH, KS and storage time was also predicted by means of the probabilistic model using logistic regression, which provided a wide range of formulation possibilities depending on the targeted shelf life.