We studied the OH oxidation of submicron aerosol particles consisting of pure palmitic acid (PA) or thin (near monolayer) coatings of PA on aqueous and effloresced inorganic salt particles. Experiments were performed as a function of particle size and OH exposure using a continuous-flow photochemical reaction chamber coupled to a chemical 5 ionization mass spectrometer (CIMS) system, for detect...

An enzyme-linked immunosorbent assay (ELISA) was compared to a gas chromatographic method for the analysis of the thiocarbamate herbicide molinate (S-ethyl hexahydroazepine-1-carbothioate). Apparent recoveries from water spiked at 1 ppb to 1 ppm levels were comparable when liquid-liquid extraction was used. Solid-phase extraction was also examined and apparent recoveries by both ELISA and gas c...

We studied the OH oxidation of submicron aerosol particles consisting of pure palmitic acid (PA) or thin (near monolayer) coatings of PA on aqueous and effloresced inorganic salt particles. Experiments were performed as a function of particle size and OH exposure using a continuousflow photochemical reaction chamber coupled to a chemical ionization mass spectrometer (CIMS) system, for detection...

effect of scale on the hydrodynamics of gas-solid fluidized beds was investigated in two fluidized beds of 152 mm and 78 mm in diameter.  air at room temperature was used as the fluidizing gas in the bed of sand particles. the radioactive particle tracking (rpt) technique was employed to obtain the instantaneous positions of the particles at every 20 ms of the experiments. these data were used ...

The production of formic acid (HCOOH) in cold and hot regions of the interstellar medium is not well understood. Recent gas-phase experiments and gas-grain models hint at a solid-state production process at low temperatures. Several surface reaction schemes have been proposed in the past decades, even though experimental evidence for their efficiency was largely lacking. The aim of this work is...

Molecules typically must point in specific relative directions to participate efficiently in energy transfer and reactions. For example, Förster energy transfer favors specific relative directions of each molecule's transition dipole [Förster T (1948) Ann Phys 2(1-2):55-75] and electron transfer between gas-phase molecules often depends on the relative orientation of orbitals [Brooks PR, et al....

In this chapter we describe how elements have been and are still being formed in the galaxy and how they are transformed into the reservoir of materials present in protostellar environments. We discuss the global cycle of matter from stars, where nucleosynthesis produces heavy elements that are ejected through explosions and winds into the interstellar medium (ISM), through the formation and ev...

Abstract A kinetic model was developed by taking into account the dynamic nature of active sites in Mars–van Krevelen type catalytic reactions to predict evolution reactant and product composition gas phase CuCl2 concentration solid catalyst. The at steady-state ethylene oxychlorination obtained combining transient experiments two half-reactions redox cycle, namely reduced CuCl oxidation oxygen...

computational fluid dynamics (cfd) simulations of gas-solid flow through a positive low-pressure pneumatic conveyor were performed using eulerian-eulerian framework. pressure drop in pneumatic conveying pipelines, creation and destruction of plugs along the horizontal and vertical pipes, effect of 90° elbows and u-bends on cross-section concentrations, and rope formation and dispersion were num...

explosion has always been regarded as one of the most complicated engineering problems. as a result, many engineers have preferred rather simplified empirical approaches in comparison to extremely complex deterministic analyses. in this paper, however, a numerical simulation based on the combined finite/discrete element methodology is presented for analyzing the dynamic behavior of fracturing r...