Production Cost

Fruit thinning has been practised for thousand of years, and serves a number of purposes. Too many fruits per tree can result in small fruit size and poor quality, breakage of limbs, exhaustion of tree reserves, and can also partially o completely inhibit bud initiation. Hand thinning of the peaches is the most common thinning practice adopted, but it is

Cellulose nanofibers with a size range of 5–100 nm have the potential to be a low cost renewable material that has application in a range of products. However, current chemical methods to produce crystalline nanofibers suffer from low yields and high chemical costs, while mechanical methods require high energy costs. Methods to lower the energy costs of the mechanical methods have not been well documented in the literature. A bleached softwood kraft pulp was processed using a mechanical dispersion mill and a homogenizer to produce cellulose nanofibers. Two different commercial enzymes were used to pretreat the wood fibers before the mechanical treatments. The resulting nanofibers were characterized by light microscopy, atomic force microscopy, and inverse gas chromatography. Results indicate that the dispersion mill does not affect the overall pulp fiber fibrillation, but does help prepare the sample for the homogenizer. Most fibrillation occurs after three passes through the homogenizer. The enzyme pretreatment has little effect on the size of the fibers, but does allow for higher solids to pass through the homogenizer without clogging. The dispersion component of surface energy of the resulting nanofibrils is impacted by the type of enzyme used. The measurement of acid–base properties proved to be challenging using current IGC experimental protocols.

Spirulina platensis was cultivated, in comparative studies, using several sources of nitrogen. The standard source used (sodium nitrate) was the same as that used in the synthetic medium Zarrouk, whereas the alternative nitrogen sources consisted of ammonium nitrate, urea, ...

Cotton farmers in many developing countries are facing decreasing marginal returns due to stagnating yields and high input costs. Conversion to organic management could offer an alternative. In a two year comparative study in central India covering 170 cotton fields, organic farms ...

The non-homothetic production cost structure in Norwegian private dentistry involves more than two factor inputs. Consequently, this paper implements-separately for solo and group practices-three conceptually different measures of factor substitutions to infer the precise nature of input associations using translog cost model estimates based on 1993 data. We calculate own- and cross-price elasticities of factor demands, pairwise elasticities of substitution and their approximate S.E.s. We find that: (1) dentists and dental assistants cannot be consistently aggregated as one homogeneous labour input; (2) input demands are inelastic; (3) the theoretically restrictive Allen-Uzawa and the less restrictive shadow and Morishima elasticities of substitution are not equivalent; (4) dentists and auxiliary dental personnel relate as significant substitutes in solo practices and as significant complements in group practices; (5) 'supplies' (e.g., dental materials) in the aggregate are substitutes for the two types of dentistry labour; and (6) there appears to be a wider scope for factor substitutions in group rather than solo practices. Due to inelastic factor demands, opportunities for cost controls are limited despite some tendencies for factor interchange. Finally, future researchers of production costs involving more than two inputs should investigate the less restrictive, alternative measures of factor substitutions.

In this paper, an advanced control system for the optimal operation and management of isolated power systems with increased renewable power integration is presented. The control system minimises the production costs through on-line optimal scheduling of the power units, taking into account short-term forecasts of the load and the renewable resources. The power system security is supervised via on-line security assessment modules, which emulate the power system frequency changes caused by pre-selected disturbances. For each of the above functions, a number of techniques have been applied, both conventional and AI based. The system has been installed in the dispatch center of Crete since June 1999, and is under evaluation

The imminent decline of the world's oil production, its high market prices and environmental impacts have made the production of biofuels to reach unprecedent volumes over the last 10 years. This is why there have been intense debates among international organizations and political leaders in order to discuss the impacts of the biofuel use intensification.Besides assessing the causes of the rise in the demand and production of biofuels, this paper also shows the state of the art of their world's current production. It is also discussed different vegetable raw materials sources and technological paths to produce biofuels, as well as issues regarding production cost and the relation of their economic feasibility with oil international prices. The environmental impacts of programs that encourage biofuel production, farmland land requirements and the impacts on food production are also discussed, considering the life cycle analysis (LCA) as a tool.It is concluded that the rise...

The building construction firms have been improved the quality of its activities due to the high market competition and the consumer's demands. In this situation, the design of the different parts of the building, including the product and the production process definitions, is fundamental to improve the costs and the building performance. The external rendering is one of the parts

We develop a model to analyze optimal product-costing and pricing decisions in a dynamic information environment under long-term-capacity commitment. The arrival of new information about demand and cost parameters each period makes the problem complex. The optimal prices and capacity choices in our model cannot be decoupled as in Banker and Hughes' (1994) single-period model. The optimal prices are based on product costs that are adjusted each period to reflect changes in expected variable costs as well as utilization of fixed activity resources. The charge for each fixed resource is monotonically increasing in the expected demand for that resource in each state given the optimal capacity choice. The average optimal prices across periods and states are similar to Banker and Hughes' (1994) benchmark prices. Finally, we investigate a two-period version of the model to explore the optimality of carrying idle capacity. The optimal product-cost charge for fixed capacity is strict...

This paper discusses an approach to solve the joint replenishment problem in a production environment with variable production cost. These variable production costs occur due to economies of scale in production. Under this environment, the model leads to a global optimization problem, which is investigated by using some standard results from convex analysis. Consequently, an effective and exact solution procedure is proposed. The proposed procedure is guaranteed to return a solution with a predetermined quality in terms of the objective function value. A computational study is provided to illustrate the performance of the proposed solution procedure with respect to the running time.