The effect of initial pH on aflatoxin production by Aspergillus parasiticus NRRL 2999 was examined in a semisynthetic medium. Maximal growth, aflatoxin production, and aflatoxin production per unit of growth occurred at initial pH levels of 5.0, 6.0, and 7.0 respectively. Initial pH levels less than pH 6.0 favored production of the B toxins, whereas levels greater than pH 6.0 favored production...

In many studies, topographic factors have been considered as an important factor in establishing the vegetation in different ecosystems. So, it affects vegetation composition and diversity by influencing soil moisture, fertility and soil depth. The aim of this research was to investigate the effects of slope, elevation and geographical aspects on species growth, forage production and vegetation...

achieving the self-sufficiency in producing agricultural crops and decreasing the pressure on the available water resources need determining the fertile places for cultivation based on the suitable evaluating indices. in this research, the prioritization of different township in sistan and blouchestan province for onion cultivation, as one of the most important production in the province, was c...

forage is the main product of rangelands. so, determining its economic value as one of the main important nonmonetary functions can help managers to improve planning and optimal utilization management of rangelands. the main purpose of this study is to estimate the economic valuation of the forage of summer rangelands in nour-roud watershed basin in mazandaran province. consequently, total fora...

analyzing efficiency in each economic sector to adopt policies for optimal use of production factors and avoid wasting resources is important. in this study, in order to have a more comprehensive evaluation of the performance of each unit, efficiency of broiler firms was measured using bounded data envelopment analysis which determines position of each unit relative to efficient and inefficient...

Current article describes application of zeolites in fluid catalytic cracking (FCC). The use of several zeolitic additives for the production light olefins and reduction of pollutants is described. Application of zeolites as fluid catalytic cracking (FCC) catalysts and additives due to the presence of active acid sites in the zeolite framework  increase the formation of desired cracking product...

We study the practical production planning problem of a food producer facing a non-stationary erratic demand for a perishable product with a fixed life time. In meeting the uncertain demand, the food producer uses a FIFO issuing policy. The food producer aims at meeting a certain service level at lowest cost. Every production run a set-up cost is incurred. Moreover, the producer has to deal wit...

This study proposes a system dynamics (SD) model to deal with the staged improvement of delivery-orientated production plan. The situations, such as the cycle time affected by total input of human resource, unit transportation cost influenced by amount of delivery quantity, unit penalty (shortage) cost affected by amount of shortages, and the time delay among customer demand, production demand,...

Intensification of agriculture has been proposed as one way of minimizing emissions per unit of product, apparently legitimizing the ongoing structural changes in agriculture. We have investigated the relationship between the farming intensity and the nitrogen (N) dissipation by calculating the overall N emission factor (E: total N surplus per unit of N in the produce) from several studies of d...

The cost of cellulase enzymes has limited the feasibility of producing ethanol from fibrous biomass. Traditional submerged fermentation (SmF) was compared to an alternative method of producing cellulase, solid state cultivation (SSC). Results from an economic analysis indicated that the unit costs for cellulase enzyme production were $15.67 (The prices are all 2004 prices in this article, excep...