An experimental study is conducted to investigate condensate drainage and retention and the attendant thermalhydraulic effect associated with changes in surface hydrophilicity on air-conditioning evaporators. Three heat exchangers that have controlled wettability covering a range of contact angles and a baseline untreated aluminum heat exchanger are tested. Results from dynamic dip-testing as w...

A distillation column with the possibility of heat exchange on every tray (a fully diabatic column) is optimized in the sense of minimizing its total entropy production. This entropy production counts the interior losses due to heat and mass flow as well as the entropy generated in the heat exchangers. It is observed that the optimal heating distribution, i.e. the heat exchange required on each...

in this research the simulation of an air independent proton exchange membrane fuel cell (pemfc) propulsion system was taken into consideration. the system consists of several parts including pem fuel cell stack, metal hydride and liquid oxygen (lox) tanks, and also pre-heaters of oxygen and hydrogen gases along with other heat exchangers, to ensure proper operation of system. the heat recovery...

The efficiency of the ideal stirling cycle assumes, that the cylinder volumes are isothermal and that the temperatures in the cylinder volumes are identical to the temperatures in the heat sink and the heat source. The efficiency is then identical to the efficiency of the Carnot cycle. However, in a real stirling machine the cylinder volumes are nearly adiabatic instead of isothermal, and the h...

An experimental database is compiled in order to fingerprint the scales formed over the hot surfaces of heat exchangers, in cooling water systems or other systems with similar chemistry. To collect these data, a dynamic simulating pilot plant was designed with considerable application flexibility among which simultaneous flow of water with different velocity and heat fluxes to three simulat...

pistachio has a special ranking among iranian agricultural products. iran is known as the largest producer and exporter of pistachio in the world. agricultural products are imposed under different thermal treatments during storage and processing. designing all these processes requires thermal parameters of the products such as specific heat capacity. regarding the importance of pistachio proces...

Results The VAP rates over the entire study period varied between 0 and 30.9/1000 ventilator days. The VAP rate for the year 2009 was 9.72 (22 VAP infections in 2263 ventilator days) which reduced to 3.43 (11 VAP infections in 3202 ventilator days) in the following year 2010 as a result of the interventions. The study showed hand hygiene compliance of the healthcare workers and length of stay o...