bubble columns are gas- liquid contactors that are widely used in chemical and bio- chemical industries. high mixing that result in high heat and mass transfer rates are amongst their advantages. heat transfer in a bubble column having a bundle of heaters investigated and the variation of heat transfer coefficient with variation in heaters pitch to diameter ratios in a bundle of heaters reporte...

Molecular dynamics simulations were used extensively in the last decades to study influence of an external electric field on many physical processes water, including mobility ions, field-induced vaporisation, and electrowetting. In most these studies, was applied as force all atoms simulation. While such approach is intuitive straightforward, it neither captures shielding by water nor any inter...

the performance of a γ-al 2 o 3 /n-decane nanofluid shell-and-tube heat exchanger in a biomass heating plant is analyzed to specify the optimum condition based on the maximum heat transfer rate and performance index for wide range of nanoparticle volume fraction (0–7%). compared with pure          n-decane, the obtained results in this research show that by using γ-al 2 o 3 /n-decane nanofluid ...

the effect of γ-al2o3 nanoparticles on heat transfer rate, baffle spacing and pressure drop in the shell side of small shell and tube heat exchangers was investigated numerically under turbulent regime. γ-al2o3-water nanofluids and pure water were used in the shell side and the tube side of heat exchangers, respectively. since the properties of γ-al2o3-water nanofluids were variable, they were ...

urban growth and associated landscape transformation has been a major driver of local, regionaland global environmental change. the conversion of urban greenery to impervious landscapes has been identifiedas a key factor influencing the distinctive urban heat and associated consequences. due to the often highdemand for space in urban areas, creation and preservation of urban greenery as heat si...

The purpose of this present work is related to wetting process analysis caused by condensation phenomena in capillary porous material by using a numerical simulation. Special emphasis is given to the study of the mechanism involved and the evaluation of classical theoretical models used as a predictive tool. A further discussion will be given for the distribution of the liquid phase for both it...

Acromegalic patients can develop obstructive sleep apnea syndrome or upper airflow obstruction. The development of dyspnea is unusual and the fixation of both vocal cords is exceptional. We report the case of a patient with bilateral vocal cord paralysis. Fiberoptic laryngoscopy and computed tomography (CT) of the neck showed a supra-glottic stenosis due to a swelling of the soft tissue. A trac...

Experimental investigations has been done to find out the heat transfer characteristics and friction factor of water based Al2O3 nanofluids as a coolant in  brazed plate heat exchanger. Plate heat exchanger either use horizontally or vertically. The base plate of the plate heat exchanger was kept inclined at (0⁰, 30⁰ ,60⁰, 90⁰). The experimentation have been done on the two different concentrat...

Tissue changes produced in the dog stomach by exposure to a Nd YAG laser varied from mild mucosal oedema to cell vaporisation. Intermediate degrees of damage caused a marked inflammatory response leading to extensive fibrosis in the submucosa and muscularis propria. The true extent of tissue damage was not apparent immediately, and treated mucosa that initially appeared intact sometimes sloughe...