We present the results of calculation and experimental testing of the tunable wavelength terahertz polarization converter represented by a set of plane-parallel birefringent plates with an in-plane birefringence axis. An experimental device has been produced and tested. The calculations show that the effect of interference between the interfaces, including air gaps, may be neglected. The consid...

The supply air from the airliner ventilation system is a mixture of outside air and recirculated air that passes through a high efficiency particulate air (HEPA) filter. The effectiveness of two commercial-available airliner cabin air filters were investigated under the laboratory-based measurement due to the practical restriction of airliner cabin filter test during usage. The filtration effic...

To minimize the chance of injury or disease from toxic or infectious substances, laboratory personnel are increasingly confining hazardous techniques to enclosed ventilated work cabinets. T'Ae well established use of the fume hood for chemistry has been extended to other laboratory sciences. The Atomic Energy Commission has been particularly active in this progress. The bacteriologist has recen...

This manuscript describes the design, characterization, and operational range of a test stand and high-output aerosol generator developed to evaluate the performance of 30 x 30 x 29 cm(3) nuclear grade high-efficiency particulate air (HEPA) filters under variable, highly controlled conditions. The test stand system is operable at volumetric flow rates ranging from 1.5 to 12 standard m(3)/min. R...

Current models and test methods for determining filter efficiency ignore filter bypass, the air that circumvents filter media because of gaps around the filter or filter housing. In this paper, we develop a general model to estimate the size-resolved particle removal efficiency, including bypass, of HVAC filters. The model applies the measured pressure drop of the filter to determine the airflo...

Here, we propose an optical filter and an optical power splitter based on two-dimensionalphotonic crystal all circular ring resonators. These structures are made of a square lattice ofsilicon rods with the refractive index n1=3.464 surrounded by air (with refractive indexn2=1). First, we have designed the filter and by using that, we designed a power splitter. Thetransmission efficiency and Qua...

Air filtration has been shown to be efficient in reducing pathogen burden in circulating air. We determined at laboratory scale the retention efficiency of different air filter types either composed of a prefilter (EU class G4) and a secondary fiberglass filter (EU class F9) or consisting of a filter mat (EU class M6 and F8-9). Four filter prototypes were tested for their capability to remove a...