DESCRIPTION In wastewater treatment processes, aeration introduces air into a liquid, providing an aerobic environment for microbial degradation of organic matter. The purpose of aeration is twofold: 1) to supply the required oxygen to the metabolizing microorganisms and 2) to provide mixing so that the microorganisms come into intimate contact with the dissolved and suspended organic matter. T...

In this paper we outline a semi-empirical procedure for predicting the broadband sound power spectrum radiated by any member of a family of geometrically similar, centrifugal blowers. The prediction scheme is based on the use of a normalized sound power spectrum that is obtained by measuring the sound power radiated by one member of the blower family. In the present instance, a lownoise blower ...

Researches into extensometric flowmeter prototype as alternative device used during measurements of air sucked in by piston engine are presented in the paper. The principle of extensometry is based on the variation in resistance of light-gauge metal wire exposed to linear strain. The advantage of designed and made extensometric flowmeter prototype is the unsophisticated design and lack of movin...

Solar photovoltaic (SPV) power systems can be employed as electrical power sources to meet the daily residential energy needs of rural areas that have no access to grid systems. In view of this, a standalone SPV powered air cooling system is proposed in this paper, which constitutes a dc-dc boost converter, two voltage source inverters (VSI) connected to two brushless dc (BLDC) motors which are...

We examined the feasibility of providing ambient air during exercise and conditioned (cooled) air during rest on reducing physiological strain and optimizing tolerance time. Six male soldiers attempted 250-min exposures in hot/dry and hot/wet environments. Subjects wore chemical protective clothing over the combat vehicle crewman uniform and an air-cooled vest. They alternated between 50 min of...

A combination of local flow measurement techniques and fog flow visualization was used to determine the inward leakage for two tight-fitting powered air-purifying respirators (PAPRs), the 3M Breathe-Easy PAPR and the SE 400 breathing demand PAPR. The PAPRs were mounted on a breathing machine head form, and flows were measured from the blower and into the breathing machine. Both respirators leak...

A low head recirculating aquaculture system has been designed, constructed, and is being tested at the Vriginia Tech Aquaculture Lab. Each recirculating system contains two grow-out tanks; a filtration vessel containing a microscreen drum filter; and four rotating biological contactor (RBC) biofilters; sixteen airlift pumps (eight per tank); a regenerative blower with air lines, vacuum lines, a...

www.thelancet.com/infection Vol 14 February 2014 99 3 Cauchemez S, Fraser C, Van Kerkhove MD, et al. Middle East respiratory syndrome coronavirus: quantifi cation of the extent of the epidemic, surveillance biases, and transmissibility. Lancet Infect Dis 2014; 14: 50–56. 4 Mangili A, Gendreau MA. Transmission of infectious diseases during commercial air travel. Lancet 2005; 365: 989–96. 5 Wagne...

The efficiency of solar photovoltaic (SPV) panels depends upon the amount of solar irradiance and spectral content. SPV panels are being widely used because of their economic and environmental merits. The performance of SPV panels gets degraded due to factors like air pollution, bird droppings, dust, snow accumulation, etc. An automatic and integrated solar panel cleaning robotic arm (SPCRA) wi...