Transformations of dissolved organic matter (DOM) in boreal lakes lead to large greenhouse gas emissions as well as substantial carbon storage in sediments. Using novel molecular characterization approaches and photochemical degradation experiments we studied how seasonal patterns in water column stratification affected the DOM in a Swedish lake under early spring and summer conditions. Dissolv...

We investigated the photochemical stability of an electro-optic (EO) polymer under laser irradiation at 1310nm to reveal photodegradation mechanisms. It was found that one-photon absorption excitation assisted with thermal energy temperature is involved in process, contrast our previous studies a wavelength 1550nm where two-photon process. Thus, both and strongly affect degradation mechanism. I...

Nowadays, society’s widespread consumption of pharmaceutical drugs and the consequent accumulation such compounds or their metabolites in effluents requires development efficient strategies systems that lead to effective degradation. This can be done through oxidative processes, which tetrapyrrolic macrocycles (porphyrins, phthalocyanines) deserve special attention since they are among most pro...

The photochemical stability of encapsulated films of mixed halide perovskites with a range of MAPb(I1-x Brx )3 (MA=methylammonium) compositions (solid solutions) was investigated under accelerated stressing using concentrated sunlight. The relevance of accelerated testing to standard operational conditions of solar cells was confirmed by comparison to degradation experiments under outdoor sunli...

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...

The degradation of trace gases and pollutants in the troposphere is dominated by their reaction with hydroxyl radicals (OH). The importance of OH rests on its high reactivity, its ubiquitous photochemical production in the sunlit atmosphere, and most importantly on its regeneration in the oxidation chain of the trace gases. In the current understanding, the recycling of OH proceeds through HO2 ...

Degradation of the most abundant membrane protein on earth, the light-harvesting complex of Photosystem II (LHC II), is highly regulated under various environmental conditions, e.g., light stress, to prevent photochemical damage to the reaction center. We identified the LHC II degrading protease in Arabidopsis thaliana as a Zn(2+)-dependent metalloprotease, activated by the removal of unknown e...