Diabatic potential energy surfaces are a convenient starting point for dynamics calculations of photochemical processes, and they can be calculated by the fourfold way direct diabatization scheme. Here we present an improved definition of the reference orbital for applying the fourfold way direct diabatization scheme to ammonia. The improved reference orbital is a geometry-dependent hybrid orbi...

In the ISA, EPA indicates that many of the overall conclusions remain generally the same as the last National Ambient Air Quality Standard (NAAQS) review which was completed in 2008. However, contrary to the EPA’s statement, the ISA includes conclusions regarding a wide-range of health effects including stronger causal associations for both short-term and long-term exposures to ozone and newer ...

The photodegradation of pesticides is reviewed, with particular reference to the studies that describe the mechanisms of the processes involved, the nature of reactive intermediates and final products. Potential use of photochemical processes in advanced oxidation methods for water treatment is also discussed. Processes considered include direct photolysis leading to homolysis or heterolysis of...

Model calculations indicate that the lower ionosphere of Saturn is controlled by photochemical processes, with basic features similar to the Jovian ionosphere. The scale height of the upper ionosphere is large (•3350 km). A peak electron density of •10•cm -s 2250 km above a 10•9cm -a reference level is expected assuming an eddy coefficient at the homopause of 1.3 x 10øcmas -• and a relatively h...

A novel setup for the direct determination of the quantum yield in photocatalytic and photochemical processes is reported. It combines the opto-electronic measurement of the absorbed amount of light with established quantitative chemical analysis of the products. High power visible LEDs are found to be convenient light sources for the illumination without the need for spectral filtering. The LE...

In an earlier paper the ozone-forming potential of n-propyl bromide (NPB) was studied with a new methodology designed to address issues associated with a marginal smog-forming compound. However, the U.S. Environmental Protection Agency (EPA) subsequently revised its policy and now recommends using the Maximum Incremental Reactivity (MIR) scale to rank the ozone-forming potential of all volatile...

We quantify the hygroscopic properties of particles freshly emitted from biomass burning and after several hours of photochemical aging in a smog chamber. Values of the hygroscopicity parameter, κ , were calculated from cloud condensation nuclei (CCN) measurements of emissions from combustion of 12 biomass fuels commonly burned in North American wildfires. Prior to photochemical aging, the κ of...

BACKGROUND Photochemical tissue bonding uses visible light to create sutureless, watertight bonds between two apposed tissue surfaces stained with photoactive dye. When applied to nerve grafting, photochemical tissue bonding can result in superior outcomes compared with suture fixation. Our previous success has focused on immediate repair. It was the aim of this study to assess the efficacy of ...

Material transports in hyaluronan (HA) aqueous solution were investigated applying two different techniques, i.e., pulsed field gradient NMR (PFG-NMR) and photochemical quenching, to the measurement of diffusion constants to show a sharp contrast resulting from the difference of the spectroscopic observation time while the same probe molecules were commonly used in two experiments. The value fr...

Photocatalytic reactions have been defined as those processes that require both a (not consumed) catalyst and light. A previous definition was whether such reactions brought a system towards or away from the (thermal) equilibrium. This consideration brings in the question whether a part of the photon energy is incorporated into the photochemical reaction products. Data are provided for represen...