The conventional design of air-conditioning plants using large-tonnage chillers calls for a condenser-water flow rate of 3 gallons-perminute-per-ton-of-refrigeration (GPM/TR). For years, this standard has been thought to offer a good balance between first cost and energy cost. Recently, this conventional design has been challenged by proponents of a 2 GPM/TR design. These proponents suggest tha...

The most critical problem in the world is to meet the energy demand, because of steadily increasing energy consumption. Refrigeration systems` electricity consumption has big portion in overall consumption. Therefore, considerable attention has been given to refrigeration capacity modulation system in order to decrease electricity consumption of these systems. Capacity modulation is used to mee...

The objective of this study was to determine the prevalence and antimicrobial resistance of Campylobacter spp. isolated from chicken carcasses during different stages of broiler processing in a major commercial poultry processing plant in southwestern Iran. Overall, 84 chicken carcasses were sampled from 4 sites along the processing line during a total of 7 visits. In addition, 14 water samples...

District cooling system (DCS) is a mass-scale production of chilled water generated at a central and remote chiller plant. Through an underground piping network, the chilled water is delivered to serve a group of consumer buildings in a district area. DCS can offer both economical and environmental benefits. Because of the substantial capital investment and running energy involved, an optimal d...

Abstract: Bi-level programming, a tool for modeling decentralized decisions, consists of the objective(s) of the leader at its first level and that is of the follower at the second level. Three level programming results when second level is itself a bi-level programming. By extending this idea it is possible to define multi-level programs with any number of levels. Supply chain planning problem...

Over the past decades, combined heat and power production (CHP) has proven itself to be an efficient means of meeting both demands. However, high efficiency can achieved with CHP plants when load is sufficient, while lower-priority must deal excess associated generation. This used for district cooling absorption chillers. Although chiller technology using generation, its very sensitive driving ...

  Bi-level programming, a tool for modeling decentralized decisions, consists of the objective(s) of the leader at its first level and that is of the follower at the second level. Three level programming results when second level is itself a bi-level programming. By extending this idea it is possible to define multi-level programs with any number of levels. Supply chain planning problems are co...

Introduction In most large air-conditioned buildings, air-handling units account for a significant portion of total building energy consumption and have a major impact on comfort conditions and maintenance costs. The devices within an air-handling unit either use energy directly in the case of fans, or indirectly, in the case of heat exchangers, which impose loads on the chiller and boiler plan...

Energy simulation programs are increasingly used to assess the energy performance of buildings and heating, ventilation, and air conditioning (HVAC) systems during design. Faults during operation can lead to considerable increase in energy use and associated operating costs. In 2009, 13 of the most common energy faults in U.S. commercial buildings were thought to cause wastes of over $3.3 billi...