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Evaluation of Norrish's equation for correlating the water activity of highly concentrated solutions of sugars, polyols and polyethylene glycols
(2010)
Abstract: Norrish’s equation, (aw = Xw exp (-K Xs 2), where aw is water activity, Xw and Xs molar fractions of water and solute, respectively, and K is the correlating constant), has been widely used to predict aw of aqueous ...
Photo-Fries Rearrangement of Some 3‑Acylestrones in Homogeneous Media: Preparative and Mechanistic Studies
(American Chemical Society, 2019-05)
Irradiation of a series of 3-acylestrones under a nitrogen atmosphere in cyclohexane, acetonitrile (MeCN), and methanol (MeOH) was investigated under steady-state conditions. The molecules underwent the photo-Fries ...
Acilação e alquilação fotoquímica de heteroarenos utilizando diacetil
(Universidade Federal de São CarlosUFSCarPrograma de Pós-Graduação em Química - PPGQCâmpus São Carlos, 2018-11-01)
N-heterocycles are important building blocks in the synthesis of bioactive compounds, besides that many of them are present in natural products. Most of the methodologies for heteroarene functionalization requires several ...
Photochemistry of ethyl esters of α-oxo-carboxylic acids
(1990)
The photochemistry of ethyl esters of α-oxo-carboxylic acids of the type RCOCO2CH2CH3 was examined using a combination of steady state irradiation and laser flash photolysis techniques. The experimental results indicate ...
Photochemical Behavior of Some Estrone Aryl and Methyl Sulfonates in Solution: Preparative and Mechanistic Studies
(Wiley Blackwell Publishing, Inc, 2021-01)
Direct irradiation of estrone aryl and methyl sulfonates in different organic solvents under nitrogen atmosphere was investigated under steady-state conditions. The estrone derivatives reacted efficiently through the ...
Determination and correlation of the water activity of unsaturated, supersaturated and saturated trehalose solutions
(Elsevier, 2008)
Abstract: The water activity (aw) of unsaturated and supersaturated trehalose solutions (and some sucrose solutions) was determined using a dew point hygrometer, and correlated using an equation originally proposed by ...
Temperature Dependence of the Photochemistry of Aryl Alkyl Ketones
(1983)
The photochemistry of several phenyl alkyl and p-anisyl alkyl ketones has been examined using laser flash photolysis and conventional quantum yield techniques. The methoxy-substituted ketones show higher activation energies ...
Photoreactivity of Oil and Alcoholic Diterpenic Varnishes: Key Role of the Polymerization Process
(2020)
he conservation of artworks is a key issue in cultural heritage. The alterations of the varnish could be linked mainly to the photopolymerization of the natural resin. The photodegrada- tion of sandarac and rosin under ...
Photolysis, tautomerism and conformational analysis of dehydroacetic acid and a comparison with 2-hydroxyacetophenone and 2-acetyl-1,3-cyclohexanodione
(Elsevier Ltd, 2020-07)
The purpose of this work was to determine the tautomerism, the conformational analysis and photoreactivity of dehydroacetic acid (DHAA, 1). For that reason, the photolysis of DHAA (1) was performed at 254 nm and compared ...
Correlación y modelamiento crioscópico de la actividad de agua en suero de queso utilizando glucosa y sacarosa
(Universidad Nacional del Centro del Perú, 2018)
En el suero de queso, permanece casi el 50 % de las proteínas, aminoácidos, vitaminas y minerales de la leche. El problema identificado es que no existen modelos matemáticos que permitan modelar el comportamiento de la ...