Clarkson University

About: Clarkson University is a education organization based out in Potsdam, New York, United States. It is known for research contribution in the topics: Particle & Turbulence. The organization has 4414 authors who have published 10009 publications receiving 305356 citations. The organization is also known as: Thomas S. Clarkson Memorial School of Technology & Thomas S. Clarkson Memorial College of Technology.

Absolute and convective instability of a liquid sheet

Abstract: The linear stability of a viscous liquid sheet in the presence of ambient gas is investigated. It is shown that there are two independent modes of instability, sinuous and varicose. The large-time asymptotic amplitude of sinuous disturbances is found to be bounded but non-vanishing for all calculated values of Reynolds numbers and the gas-to-liquid density ratios when the Weber number is greater than one half. The Weber number We is defined as the ratio of the surface tension force to the inertia force per unit area of the gas–liquid interface. When We is smaller than one half, the sinuous mode is stable if the gas-to-liquid density ratio is zero, otherwise it is convectively unstable. The varicose mode is always convectively unstable unless the density ratio, Q, is zero. Then it is asymptotically stable. The spatial growth rate of the varicose mode is smaller than that of the sinuous mode for the same flow parameters. The wavelength of the most amplified waves in both modes is found to scale with the product of the sheet thickness and Q/We. It is shown, by use of the energy equation, that the mechanism of instability is a capillary rupture when We [ges ] 0.5, and the convective instability is due to the interfacial pressure fluctuation when We < 0.5.

Characterization of residential wood combustion particles using the two-wavelength aethalometer.

Abstract: In the United States, residential wood combustion (RWC) is responsible for 7.0% of the national primary PM2.5 emissions. Exposure to RWC smoke represents a potential human health hazard. Organic components of wood smoke particles absorb light at 370 nm more effectively than 880 nm in two- wavelength aethalometer measurements. This enhanced absorption (Delta-C = BC370 nmBC880 nm) can serve as an indicator of RWC particles. In this study, aethalometer Delta-C data along with measurements of molecular markers and potassium in PM2.5 were used to identify the presence of airborne RWC particles in Rochester, NY. The aethalometer data were corrected for the loading effect. Delta-C was found to strongly correlate with wood smoke markers (levoglucosan and potassium) during the heating season. No statistically significant correlation wasfoundbetweenDelta-Candvehicleexhaustmarkers.TheDelta-Cvalueswere substantially higher during winter compared to summer. The winter diurnal pattern showed an evening peak around 21:00 that was particularly enhanced on weekends. A relationship between Delta-C and PM2.5 was found that permits the estimation of the contribution of RWC particles to the PM mass. RWC contributed 17.3% to the PM2.5 concentration during the winter. Exponential decay was a good estimator for predicting Delta-C concentrations at different winter precipitation rates and different wind speeds. Delta-C was also sensitive to remote forest fire smoke.