Although the hydraulic jump has been investigated experimentally for nearly two centuries, little information is known of the air-water flow properties in the shear region. New experiments were performed in a horizontal channel with partially-developed inflow conditions. Distributions of air concentration, mean air-water velocity and bubble frequency were recorded and presented herein. The resu...

Investigations were carried out on coal tailings by conventional cell and column flotation techniques. Tests were conducted to assess processing coal tailings of Alborz Markazi coal washing plant in Iran by column flotation. The effects of reagent type/dosage were investigated with conventional flotation and their results were used in the performance of column flotation. Also the effects of the...

Introduction Traditionally a Pitot-static tube connected to a pressure transducer is used to make air velocity measurement. Lately, velocity transducers based on the principle of convective heat transfer have become popular. Both types of transducers need occasional calibrations. Also, several regulatory agencies require that the calibration of velocity transducers used in certain applications ...

The well known zero in the group velocity of the first-order symmetric (S1) plate wave mode has been exploited in air-coupled ultrasonic imaging to obtain significantly higher sensitivity than can be achieved in conventional air-coupled scanning. At the zero group velocity point at the frequency minimum of the S1 mode, a broad range of wavenumbers couple into the first-order symmetric mode at n...

This work examines the ability of small-scale helium–air mixture coaxial jets to simulate the acoustics of largescale hot air jets representing the exhaust of separate-flow turbofan engines. Experiments employed a one-eighthscale model of a separate-flow nozzle used in hot tests at NASA John H. Glenn Research Center. Comparisons were conducted for two set points using the following methods: mat...

The rearing of poultry for meat production (broilers) is an agricultural food industry with high relevance to the economy and development of some countries. Periodic episodes of extreme climatic conditions during the summer season can cause high mortality among birds, resulting in economic losses. In this context, ventilation systems within poultry houses play a critical role to ensure appropri...

The present work studies the effect of three insect-proof screens with different geometrical and aerodynamic characteristics on the air velocity and temperature inside a Mediterranean multi-span greenhouse with three roof vents and without crops, divided into two independent sectors. First, the insect-proof screens were characterised geometrically by analysing digital images and testing in a lo...

Factors were analyzed that limit the range of environmental conditions in which stress from heat may be relieved by evaporative cooling in shaded animals. Evaporative cooling reduces air temperature (Ta), but increases humidity. Equations were developed to predict Ta reduction as a function of ambient temperature and humidity and of humidity in cooled air. Predictions indicated that a reduction...