Photochemical mechanisms are a critical module of air quality models. In the past 20 years, several mechanisms have been developed to study the chemistry of the troposphere. This work compares several state-of-the-science photochemical mechanisms (including LCC, CBM-IV, RADM2, EMEP, RACM, SAPRC99, and CACM which have never been compared before in other studies). Concise descriptions of the chem...

An analysis procedure has been developed for derivation of information about the photochemical behavior of ozone near 1 mbar by explicitly accounting for the dynamical transport terms in the continuity equation for perturbations from the zonal mean. The procedure is shown to be valid using data from a numerical transport model and is then applied to LIMS ozone and temperature data, using geostr...

Sunlight induces photochemical mineralisation of chromophoric dissolved organic matter (CDOM) to dissolved inorganic carbon (DIC) in inland waters, resulting in carbon dioxide (CO2) emissions to the atmosphere. Photochemical rate modelling is used to determine sunlightinduced CO2 emissions on large spatial and temporal scales. A sensitive model parameter is the wavelength-specific photochemical...

The "edge" of the Antarctic polar vortex is known to behave as a barrier to the meridional (poleward) transport of ozone during the austral winter. This chemical isolation of the polar vortex from the middle and low latitudes produces an ozone minimum in the vortex region, intensifying the ozone hole relative to that which would be produced by photochemical processes alone. Observational determ...

Understanding new particle formation and their subsequent growth in the troposphere has a critical impact on our ability to predict atmospheric composition and global climate change. High pre-existing particle loadings have been thought to suppress the formation of new atmospheric aerosol particles due to high condensation and coagulation sinks. Here, based on field measurements at a mountain s...

A mixed-phase chemistry box model is applied to study heterogeneous chemistry and its effect on tropospheric gas-phase chemistry, particularly on photochemical production of O3 and photochemical indicators for O3-NOx-hydrocarbon sensitivity, under a variety of atmospheric conditions ranging from remote marine to heavily-polluted atmospheres. A subsequent sensitivity analysis of the mixed-phase ...

in this paper, the photochemical degradation of azure-b by cu2+/s2o82− process has beenpresented. cu2+ as photocatalyst and s2o82− ion as photooxidant used in this process. atextremely low concentrations, cupric ion showed true catalytic activity in the overall process.the influence of various parameters on the performance of the treatment process has beenconsidered, such as ph, concentration o...

The heat, ultraviolet and rihoflavin-sensitized visible inactivations of taka-amylase A are strongly inhibited by the presence of its substrate. The stabilization of the secondary structure of enzyme protein by the conformation change due to the formation of enzyme-substrate and -product complexes is responsible for the protection of enzyme from the heat inactivation. The photoinactivations are...

Phytochromes are multi-domain red light photosensor proteins, which convert red light photons to biological activity utilizing the multitude of structural and chemical reactions. The steady increase in structural information obtained from various bacteriophytochromes has increased understanding about the functional mechanism of the photochemical processes of the phytochromes. Furthermore, a num...