On the optimality of output inventory decisions of a firm under imperfect stochastic markets

A class of suboptimal strategies in price, output and inventories is proposed for a firm in imperfectly competitive stochastic markets. When the demand faced is incompletely known and inventories are held partly as a buffer against fluctuations in demand, and partly as active decision variables, the solution is characterized by maximizing expected profits over two periods with an additive error in the demand function having a known prior density. Simulations of the solution profiles show that for the two-period moving horizon model proposed here, the variance of profits and revenues are sharply reduced, a feature that is most attractive for a risk averse firm.     

ENHANCEMENT OF PYRUVIC ACID RELEASE AND FLAVOR IN DEHYDRATED ALLIUM POWDERS BY GAMMA GLUTAMYL TRANSPEPTIDASES

SUMMARY —The transpeptidase of sprouted onion, in conjunction with both endogenous and exogenous cysteine (sulfoxide) lyases, catalyzes the liberation of pyruvic acid from γ-L-glutamyl-L-cysteine (sulfoxide) dipeptides (precursors to flavor precursor) and increases the rate and extent of pyruvic acid formation and flavor in reconstituted samples of commercially dehydrated garlic and onion bulbs as well as in experimentally dehydrated onion roots and skins. Effects of enzyme concentration, time, pH, exogenous lyase and protease, as well as sample source have been investigated. The application of these enzymes may constitute a rapid and simple means for estimation in plants of the above mentioned dipeptides which appear, from such an analysis, to concentrate in the inner part of the onion bulb. Transpeptidases may be useful in enhancing the value and quality of dehydrated onion and garlic and other Allium species, improving the flavor of Allium-containing foods, as well as providing a use for a waste product, cull-sprouted onions. Other sources of transpeptidase such as mammalian kidney may also be suitable for enhancing onion flavor.     

ELECTROGENERATIVE OXIDATION OF ETHANOL TO ACETALDEHYDE

Ethanol enriched vapor streams from twenty-five volume percent ethanol-water mixtures can be selectively oxidized with porous platinum electrodes and sulfuric acid electrolyte in the elec-trogeneratice mode to give acetaldehyde. Acetaldehyde yield from ethanol depends on potential and feed rate of ethanol vapor in the carrier gas stream. Control of conversions of ethanol to acetaldehyde in the range of 3 to more than 60 percent in a single stage is demonstrated. It is shown that at moderate flow rates for selective conversion there is a preferred potential range at which to operate the electrogenerative reactor.     

Optimization of a Diced Tomato Calcification Process

The effect of calcium concentration (0.05-1.45% CaCl₂), temperature of dipping solution (35-65°C), and contact time (0.5-3.5 min) on calcium uptake, firmness and pH of diced tomatoes was evaluated during a calcification process using response surface methods. Temperature had no significant effect on the process. Application of graphical optimization techniques revealed that processing in a solution of relatively low calcium concentration (?0.43% CaCl₂) at ambient temperature (? 35°C) for about 3.5 min would yield a product with Ca⁺⁺ content below the legal limit (<800 μ-g/g), improved firmness (shear force value > 20 N/g), and with pH low enough (<3.95) to eliminate any requirement for acidification treatment.     

Production scheduling decision rules in changing and non-linear environments

Holt at al. (1960) modollod the production scheduling problem with quadratic costs and derived an optimal set of scheduling rules. Our experiment found those rules may not be effective if costs are non-quadratic. This may explain the relative lack of use of these rules in industry.     

Vapor Analysis of the Production by Banana Fruit of Certain Volatile Constituents

SUMMARY: Direct gas chromatographic vapor analyses were utilized to determine whether banana slices at different stages of ripeness in an in vitro system produced iso-amyl acetate and iso-amyl alcohol, known banana aroma constituents; and whether a precursor-product relationship could be observed between these compounds and L-leucine. Production of iso-amyl acetate by unripe slices was demonstrated based on experiments with metabolic inhibitors. The behavior of ripe and overripe slices was inconclusive since the vapor concentration of the acetate remained constant. The vapor concentration of iso-amyl alcohol was essentially unchanged at all ripeness stages. Investigations with L-leucine-U-¹⁴C showed conclusively that leucine was a precursor and that both compounds were continually produced at all ripeness stages. The interpretation of direct vapor analyses over respiring fruit is considered.     

Heat sensitivity of Mycobacterium avium ssp. paratuberculosis in milk under pilot plant pasteurization conditions†

Raw cow's milk inoculated with four laboratory strains (10²?10⁵ cfu/mL) of Mycobacterium avium ssp. paratuberculosis (Map) was pasteurized in a custom designed pilot plant pasteurizer having a maximum throughput of 580 L/h under turbulent flow conditions. Following 16 pasteurizer trials none of the Map strains survived high‐temperature short‐time conditions (72.5°C × 27 s) whether milk was homogenized or not. Two dairy herds containing animals which were faecal positive for Map were sourced and milk was collected for pasteurization studies. Milk collected from one herd on five occasions in the autumn did not contain any detectable Map organisms, and the second herd that was sampled on only one occasion in early winter was shown to contain Map at low concentration. Map was not detected in any of these milks following pasteurization at 72.5°C for 27 s. Two natural isolates of Map inoculated into milk were likewise inactivated on pasteurization.