Nowadays, in some small and medium-sized heat pumps, refrigerant R410A has been used widely because of the good thermodynamic performance and environmental protection. Firstly the principles of the system and the characteristics of refrigerant has been demonstrates. The paper has set up a heat pump system with the refrigerant R410A and the performance parameters under different working conditio...

acid-binding capacity (abc) of a feed is the amount of acid required to reduce the ph of feed to a special level such as 3. all poultry feed ingredients used in this study were collected from feed mills in iran. the ph and abc were determined using the standard methods in deionized and magnetized water at room and body temperatures. the ph of most feed ingredients was raised in magnetized water...

in this study, a bearing capacity device is designed and fabricated to determine the load-settlement behavior of three circular footing models resting above the ground water table. capillary rise in the studied well graded sand is measured and the level of the water table is controlled at the desired heights during each bearing capacity test. moreover, shear strength parameters and soil water r...

Recent droughts and increasing temperatures have resulted in extensive tree mortality across the globe. Understanding the environmental controls on tree regeneration following these drought events will allow for better predictions of how these ecosystems may shift under a warmer, drier climate. Within the widely distributed piñon-juniper woodlands of the southwestern USA, a multiyear drought in...

conclusions by combining the two tests, a rapid approach to estimation of most probable number of chlorinated methane utilizing bacteria is introduced. treatment by nanosilver particles was resulted in the easier and faster biodegradation of chloroform by bacteria. thus, degradation of these chlorinated compounds is more efficient compared to cometabolism. results most probable number of methyl...

water deficit stress permanent or temporary limits the growth and distribution of natural vegetation and performance of plants more than other environmental factors. in order to investigate the effect of drought stress and mycorrhizal-arbuscular fungi inoculation on the growth and yield of savory (satureja hortensis l.) a factorial experiment based on completely randomized design were conducted...

playas are low-lands which is considered to be the locations of accumulation of superficial and ground waters fromhigher elevations and these waters have different types of salts and various salinity level. therefore, because of lack ofrainfall and fresh-water both for human and animal useage or even for plants, it is needed to apply proper methods toharvest fresh water from these saline-waters...

The US National Research Council recently recommended direct potable water reuse (DPR), or potable water reuse without environmental buffer, for consideration to address US water demand. However, conveyance of wastewater and water to and from centralized treatment plants consumes on average four times the energy of treatment in the USA, and centralized DPR would further require upgradient distr...