This paper predicts the reductions in the indoor mass concentrations of particles attainable from use of filters in building supply airstreams and also from use of stand-alone fan-filter units. Filters with a wide efficiency range are considered. Predicted concentration reductions are provided for indoor-generated particles containing dust-mite and cat allergen, for environmental tobacco smoke ...

The objectives of this study were to describe the relationships between milk urea concentrations and nutritional management, production, and economic variables in commercial dairy herds. Dairy Herd Improvement (DHI) test-day milk urea data, production data, and information on ration nutrient composition and feeding management programs were collected over a 13-mo period from 53 commercial Ontari...

conclusions accidents resulting in death, total disability and partial disability impose huge costs that are borne by society, and employers bear relatively low costs due to the health, treatment and welfare systems provided by society for the treatment and rehabilitation of injured workers and their families. also, the results of this study show that investment in the hse-ms is effective and a...

In this paper the problem of minimum cost communication network design is considered where the costs are piecewise linear concave. Several methods are compared: Simulated Annealing method, a heuristic based on the method proposed by Minoux, and a lagrangian method based on lower bounding procedure.

Recent evidence on the savings from private production of local public services has become increasingly ambiguous. Here we specify and estimate a model to explain municipal costs for solid waste collection. As we find no effect of the mode of production on costs, we put forward two hypotheses. First, progressive concentration and decreases in bidding competition may come to outweigh gains from ...

This paper studies the impact of trade costs reduction on geographical concentration in the presence of firm heterogeneity and overhead type of export fixed costs. Firm heterogeneity with the export fixed costs hampers full agglomeration through weakening the forward and backward linkages and fortifying the market crowding effect. Rather than catastrophic agglomeration that the standard new eco...

Chronic fatigue syndrome is characterised by severe, disabling fatigue, and other symptoms such as musculoskeletal pain, sleep disturbance, impaired concentration and headaches (Reid 2007). The prevalence of chronic fatigue syndrome has been estimated to be from 0.007% to 2.8% in the general adult population, and from 0.006% to 3.0% in primary care, depending on the criteria used (Afari 2003). ...

The paper develops and estimates a generalized investment model of the firm, using dynamic dual approach. Optimal zero investments are allowed to arise either from generalized adjustment costs, uncertainty, or both. The results suggest that hog production technology exhibits both shortand long-run size economies. Environmental regulations are, therefore, going to play an increasingly important ...

introduction: cost estimation is a important tool which assist the managers to plan and to control the economic functions of the organization. the present study aims to identify the cost of a cesarean surgery in one of the first class public hospitals in iran. methodology: reviewing all expenses of the hospital documents in the financial unit, the cost of a cesarean surgery was determined throu...