there is no single standard technique or methodology to characterize the size, structure, number, and chemical composition of airborne carbon nanotubes.  existing analytical instruments and analytical techniques for evaluating nanoparticle concentrations cannot simultaneously provide morphology, state of agglomeration, surface area, mass, size distribution and chemical composition data critical...

There is no single standard technique or methodology to characterize the size, structure, number, and chemical composition of airborne carbon nanotubes.  Existing analytical instruments and analytical techniques for evaluating nanoparticle concentrations cannot simultaneously provide morphology, state of agglomeration, surface area, mass, size distribution and chemical composition data critical...

Rugate designs for the realization of notch filters are well known in the literature. The required deposition of gradient index layers is difficult to manufacture. In our approach we apply the equivalent index theory to replace the gradient index profile of a notch filter design. We produce single and multiple notch filters with plasma ion-assisted deposition and broad-band optical monitoring. ...

A technique of computing the pressure drop and deposition rate evolution during soot loading and the 3D distribution of deposited soot particles for micro-structured ceramic filter media is presented. Methods developed at Fraunhofer ITWM for generating 3D computer models representing the microstructure of the filter material and for computing soot particle deposition in the microstructure model...

To reduce particulate matter (PM) including soot in diesel exhaust gas, a diesel particulate filter (DPF) has been developed. Since it is difficult to observe the phenomena in a DPF experimentally, we have conducted a lattice Boltzmann simulation. In this study, we simulated the flow in a metallic filter. An X-ray computed tomography (CT) technique was applied to obtain its inner structure. The...

Miners are exposed to silica-bearing dust which can lead to silicosis, a potentially fatal lung disease. Currently, airborne silica is measured by collecting filter samples and sending them to a laboratory for analysis. Since this may take weeks, a field method is needed to inform decisions aimed at reducing exposures. This study investigates a field-portable Fourier transform infrared (FTIR) m...

In this paper an optical system for measuring the amount of dust deposition on commercial bag filters is presented. Dust laden gas is blown onto the filter, the dust remains on the surface and forms a compact layer called filter cake. For academic simulations as well as practical filter design it is desirable to know the thickness of this cake over the filter surface during operation, when the ...