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Full-Text Articles in Chemistry
Predicting The Reactivities And Reaction Mechanisms Of Photochemically Produced Reactive Intermediates, Benjamin Barrios Cerda
Predicting The Reactivities And Reaction Mechanisms Of Photochemically Produced Reactive Intermediates, Benjamin Barrios Cerda
Dissertations, Master's Theses and Master's Reports
Photochemically produced reactive intermediates (PPRIs) such as the hydroxyl radical, carbonate radical (CO3•-) singlet oxygen (1O2) and triplet state of chromophoric dissolved organic matter (3CDOM*) are formed in sunlit natural waters upon photoexcitation of chromophoric dissolved organic matter (CDOM). PPRIs react with the organic compounds involved in key environmental processes, resulting in transformation products of smaller molecular weight than their parent compounds. Photochemical transformation of these key water constituents due to their reactions with PPRIs may pose potential effects on human and aquatic ecosystems. Consequently, there is a need …
The Effects Of Reactant Concentration And Air Flow Rate In The Consumption Of Dissolved O2 During The Photochemistry Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman
The Effects Of Reactant Concentration And Air Flow Rate In The Consumption Of Dissolved O2 During The Photochemistry Of Aqueous Pyruvic Acid, Alexis J. Eugene, Marcelo I. Guzman
Chemistry Faculty Publications
The sunlight photochemistry of the organic chromophore pyruvic acid (PA) in water generates ketyl and acetyl radicals that contribute to the production and processing of atmospheric aerosols. The photochemical mechanism is highly sensitive to dissolved oxygen content, [O2(aq)], among other environmental conditions. Thus, herein we investigate the photolysis (λ ≥ 305 nm) of 10–200 mM PA at pH 1.0 in water covering the relevant range 0 ≤ [O2(aq)] ≤ 1.3 mM. The rapid consumption of dissolved oxygen by the intermediate photolytic radicals is monitored in real time with a dissolved oxygen electrode. …
Cross Photoreaction Of Glyoxylic And Pyruvic Acids In Model Aqueous Aerosol, Sha-Sha Xia, Alexis J. Eugene, Marcelo I. Guzman
Cross Photoreaction Of Glyoxylic And Pyruvic Acids In Model Aqueous Aerosol, Sha-Sha Xia, Alexis J. Eugene, Marcelo I. Guzman
Chemistry Faculty Publications
Aerosols of variable composition, size, and shape are associated with public health concerns as well as with light-particle interactions that play a role in the energy balance of the atmosphere. Photochemical reactions of 2-oxocarboxylic acids in the aqueous phase are now known to contribute to the total secondary organic aerosol (SOA) budget. This work explores the cross reaction of glyoxylic acid (GA) and pyruvic acid (PA) in water, the two most abundant 2-oxocarboxylic acids in the atmosphere, under solar irradiation and dark thermal aging steps. During irradiation, PA and GA are excited and initiate proton-coupled electron transfer or hydrogen abstraction …
Mechanisms Of Euv Exposure : Photons, Electrons And Holes, Amrit Kausik Narasimhan
Mechanisms Of Euv Exposure : Photons, Electrons And Holes, Amrit Kausik Narasimhan
Legacy Theses & Dissertations (2009 - 2024)
The microelectronics industry’s movement toward smaller and smaller feature sizes has necessitated a shift to Extreme Ultra-Violet (EUV) lithography to be able to pattern sub 20-nm features, much like earlier shifts from i-line to 248 nm. However, this shift from 193-nm lithography to EUV (13.5 nm) poses significant obstacles. EUV is the first optical lithography to operate in an energy range (92 eV per photon vs. 6.4 eV per photon for 193 nm lithography) above the electron binding energies of common resist atomic species. This significant energy increase complicates resist design. For exposures of equal dose, resists receive 14 times …
Prospects Of D-Π-A Structured Porphyrins And Their Photoelectrochemical Application, Shuang-Shuang Liu, Jian-Feng Lu, Ming-Kui Wang
Prospects Of D-Π-A Structured Porphyrins And Their Photoelectrochemical Application, Shuang-Shuang Liu, Jian-Feng Lu, Ming-Kui Wang
Journal of Electrochemistry
Porphyrins and their metalloderivatives are a class of compounds exhibiting a wide variety of interesting and highly useful properties, such as chlorophyll. Porphyrins are particularly interesting in photoelectrochemical applications due to their structural similarity to chlorophylls in natural photosynthetic systems, as well as their strong and tunable absorption properties. Recently, various porphyrins have been extensively studied for their applications in solar cells, photocatalytic hydrogen production, optical information storage and others. This review will focus on the unique physical and chemical properties of D-π-A structured porphyrins, and their photovoltaic performances in dye-sensitized solar cells. A brief discussion in the future development …
Aqueous Photochemistry Of Glyoxylic Acid, Alexis J. Eugene, Sha-Sha Xia, Marcelo I. Guzman
Aqueous Photochemistry Of Glyoxylic Acid, Alexis J. Eugene, Sha-Sha Xia, Marcelo I. Guzman
Chemistry Faculty Publications
Aerosols affect climate change, the energy balance of the atmosphere, and public health due to their variable chemical composition, size, and shape. While the formation of secondary organic aerosols (SOA) from gas phase precursors is relatively well understood, studying aqueous chemical reactions contributing to the total SOA budget is the current focus of major attention. Field measurements have revealed that mono-, di-, and oxo-carboxylic acids are abundant species present in SOA and atmospheric waters. This work explores the fate of one of these 2-oxocarboxylic acids, glyoxylic acid, which can photogenerate reactive species under solar irradiation. Additionally, the dark thermal aging …