here, we have synthesized vertically aligned carbon nanotubes (va-cnts), using chemical vapor deposition (cvd) method. cobalt and ethanol are used as the catalyst and the carbon source, respectively. the effects of ethanol flow rate, thickness of co catalyst film, and growth time on the properties of the carbon nanotube growth are investigated. the results show that the flow rate of ethanol and...

the pull- out strength of the reinforcement has a significant role on the function of the most reinforced soil structures. since the coarse grain soils have a better interaction with the reinforcement, they are mostly used in these structures. in most situations, we have to transfer these granular soils from the borrow area, usually far from the site of the project. this will impose a considera...

Various concepts for oil evaporation prediction are summarized. Models can be divided into those models that use the basis of air-boundary-regulation or those that do not. Experiments were conducted to determine if oil and petroleum evaporation is regulated by the saturation of the air boundary layer. Experiments included the examination of the evaporation rate with and without wind, in which c...

this paper presents mathematical models of thin layer forced convection solar drying of cuminum cyminum using two drying methods (mixed and indirect) at different operating conditions. the average initial moisture content of the seeds for all tests was about 43% d.b. and the drying was performed continuously, in each test, for a uniform period of 90 minutes drying time in a solar cabinet dryer ...

drying properties of high moisture potato slices with initial moisture content of about 4.06 (db) under thin layer fixed, semi fluidized and fluidized bed conditions were studied. drying air temperatures of 40, 50, 60 and 70°c were applied in experiments using a laboratory fluidized bed convective dryer. in order to predict the drying behavior of potato slices, seven thin layer drying models we...

turbulent fluxes in the atmospheric boundary layer are calculated using different models. one of the most popular and operational models in this groundwork is the second order turbulent model of mellor and yamada that has been widely used to simulate the planetary boundary layer (pbl). despite its popularity, it has been shown that this model has several weeknesses that affect its accuracy. the...

the entrainment of a stably stratified layer into a turbulent mixed layer in a confined region has been studied in the laboratory for different richardson numbers, ri. the results include direct observation of turbulent characteristics and density measurements using two high precision salinity meters. the measurements include turbulence intensity, scale of eddies near the interface and energy s...