Although the mathematics that define the operation of an impeller can be complex (it is the stuff of Bernoulli and Euler), its purpose is straight forward. An impeller is designed to impart energy to a fluid so that it will flow or, if it is already flowing, undergo some increase in its elevation or pressure. It accomplishes this by increasing the fluid’s velocity as it travels through its vane...

purpose: to evaluate the effect of preoperative eyelash trimming on periocular bacterial flora. methods: one hundred patients divided into two groups. fifty cases (group 1) had eyelash trimming prior to phacoemulsification and other fifty patients (group 2) did not. none of the study participants had been diagnosed as having an active ocular infection prior to surgery. patients taking topical a...

Lipase-catalyzed production of palm esters by alcoholysis of palm oil with oleyl alcohol in n-hexane was performed in 2L stirred-tank reactor (STR). Investigation on the performance of reactor operation was carried out in batch mode STR with single impeller mounted on the centrally located shaft. Rushton turbine (RT) impellers provide the highest reaction yield (95.8%) at lower agitation speed ...

In the present work, the effects of dual impeller configurations comprising of Rushton turbine (RT) and Concave-bladed disk turbine (CD-6) on the oxygen transfer profile and fermentation performance of kojic acid production by Aspergillus flavus Link 44-1 was investigated. Batch cultivations of A. flavus Link 44-1 were performed in 2 L stirred tank bioreactor. The fermentations were conducted u...

The changes in chemical production processes, in particular the shift from chemical production to biotechnology, puts more emphasis on shear rate control of mixing devices. At the same time, mixing devices should be highly optimized with respect to power consumption, both for economical reasons and due to the prevention of additional heat-up of the mixing process. In addition, most biotechnolog...

Axial pumps have a wide range of applications, and cavitation is one of the main causes of there performance degradation. So, the present study investigates experimentally and numerically the performance of cavitating axial pumps. In this study a three-dimensional Navier-Stokes code was used (CFDRC, 2004) to model the two-phase flow field around a four blades axial pump. The governing equations...

The periodic trimming of the long hairs growing at the distal end of the tail -switch trimming- is humane alternative of tail docking. The purpose of this study was to determine the influence of switch trimming on somatic cell count (SCC), California mastitis test (CMT) and udder cleanliness of lactating cows in a free-stall dairy farm. In the present study, 219 healthy, pregnant Holstein cows ...

This study aimed at verifying if beak-trimming methods in Japanese quail pullets could optimize production by decreasing stress caused by cannibalism. A total number of 816 day-old Japanese quails was distributed in a completely randomized experimental design in a 2 x 3 factorial arrangement, with two beak-trimming ages (14 and 21 days of age) and three beak-trimming sizes (not trimmed, 1/3 tri...