scholarly journals Response Kinetics of Tethered Rhodobacter sphaeroides to Changes in Light Intensity

2000 ◽  
Vol 78 (3) ◽  
pp. 1207-1215 ◽  
Author(s):  
Richard M. Berry ◽  
Judith P. Armitage
Keyword(s):  
Light Intensity ◽  
Rhodobacter Sphaeroides ◽  
Kinetics Of

Light-Intensity Dependence In The Kinetics Of N-Gap Photoelectrode Stabilization

2010 ◽  
Vol 89 (3) ◽  
pp. 181-186 ◽  
Author(s):  
F. van Overmeire ◽  
F. Vanden Kerchove ◽  
W. P. Gomes ◽  
F. Cardon
Keyword(s):  
Light Intensity ◽  
Intensity Dependence ◽  
Kinetics Of

scholarly journals Characteristics and Kinetics of Rosin Pentaerythritol Ester via Oxidation Process under Ultraviolet Irradiation

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 2816 ◽  
Author(s):  
Yuanlin Li ◽  
Xiongmin Liu ◽  
Qiang Zhang ◽  
Bo Wang ◽  
Chang Yu ◽  
...  
Keyword(s):  
Light Intensity ◽  
Oxidation Kinetics ◽  
Pseudo First Order Reaction ◽  
Initial Oxidation ◽  
Photo Oxidation ◽  
Average Value ◽  
Pentaerythritol Ester ◽  
Fundamental Information ◽  
The Stability ◽  
Kinetics Of

A self-designed reaction device was used as a promising equipment to investigate the oxidation characteristics and kinetics of rosin pentaerythritol ester (RPE) under UV irradiation. Photo-oxidation kinetics and the initial quantum yield (Φ) of RPE were calculated. The initial oxidation product of the photo-oxidation reaction—peroxide was analyzed by iodimetry. The peroxide concentration is related to the light intensity (I) and the temperature (T), and the increasing T and I would destabilize the RPE by accelerating peroxide forming. Photo-oxidation of RPE follows the pseudo first-order reaction kinetics. The relationship between activation energy and logarithm of light intensity (ln I) is linear, and it is expressed as Ea = −4.937ln I + 45.565. Φ was calculated by the photo-oxidation kinetics, and the average value of Φ was 7.19% in the light intensity range of 200–800 μW cm−2. This research can provide fundamental information for application of RPE, and help obtain a better understanding of the stability of rosin esters.

scholarly journals Kinetics of bulk photo-initiated copper(i)-catalyzed azide–alkyne cycloaddition (CuAAC) polymerizations

2016 ◽  
Vol 7 (3) ◽  
pp. 603-612 ◽  
Author(s):  
Han Byul Song ◽  
Austin Baranek ◽  
Christopher N. Bowman
Keyword(s):  
Light Intensity ◽  
Exposure Time ◽  
Copper Salt ◽  
Solvent Content ◽  
Kinetics Of

Kinetics of bulk photo-initiated copper(i)-catalyzed azide–alkyne cycloaddition (CuAAC) polymerizations is governed by several factors including the physicochemical nature of the monomers; the copper salt and photoinitiator types and concentrations; light intensity; exposure time and solvent content.

Acquired tolerance of the photosynthetic apparatus to photoinhibition as a result of growing Solanum lycopersicum at moderately higher temperature and light intensity

2019 ◽  
Vol 46 (6) ◽  
pp. 555 ◽  
Author(s):  
Milena T. Gerganova ◽  
Aygyun K. Faik ◽  
Maya Y. Velitchkova
Keyword(s):  
High Temperature ◽  
Quantum Yield ◽  
Light Intensity ◽  
Electron Flow ◽  
Photosynthetic Apparatus ◽  
High Light ◽  
Cyclic Electron Flow ◽  
Photochemical Quenching ◽  
Kinetics Of ◽  
Moderately High Temperature

The kinetics of photoinhibition in detached leaves from tomato plants (Solanium lycopersicum L. cv. M82) grown for 6 days under different combinations of optimal and moderately high temperature and optimal and high light intensity were studied. The inhibition of PSII was evaluated by changes in maximal quantum yield, the coefficient of photochemical quenching and the quantum yield of PSII. The changes of PSI activity was estimated by the redox state of P700. The involvement of different possible protective processes was checked by determination of nonphotochemical quenching and cyclic electron flow around PSI. To evaluate to what extent the photosynthetic apparatus and its response to high light treatment was affected by growth conditions, the kinetics of photoinhibition in isolated thylakoid membranes were also studied. The photochemical activities of both photosystems and changes in the energy distribution and interactions between them were evaluated by means of a Clark electrode and 77 K fluorescence analysis. The data showed an increased tolerance to photoinhibition in plants grown under a combination of moderately high temperature and light intensity, which was related to the stimulation of cyclic electron flow, PSI activity and rearrangements of pigment–protein complexes, leading to a decrease in the excitation energy delivered to PSII.

Persistent photoconductivity in AlGaN films Grown by mocvd

1998 ◽  
Vol 512 ◽  
Author(s):  
A. Y. Polyakov ◽  
N. B. Smirnov ◽  
A. V. Govorkov ◽  
J. M. Redwing
Keyword(s):  
Activation Energy ◽  
Light Intensity ◽  
High Resistivity ◽  
Persistent Photoconductivity ◽  
Quasi Fermi Level ◽  
Decay Times ◽  
Long Time ◽  
Light Excitation ◽  
Si Doped ◽  
Kinetics Of

ABSTRACTPhotocurrent transients due to illumination by above-bandgap and subbandgap light were studied for Si doped and undoped films of AlGaN grown by MOCVD on sapphire and having compositions ranging from 0% to 60% of Al. It is shown that in Si doped layers the decay of photoconductivity takes extremely long time (hundreds and thousands seconds, depending on temperature, composition and illumination conditions). Both the kinetics of rise and fall of photoconductivity are best described by stretched exponents. The characteristic decay times are virtually temperature independent for temperatures below 270–290K and have activation energy of 0.14–0.26 eV (depending on composition) for higher temperatures. The decay times become longer with decreased light intensity and increase when above-bandgap light excitation is replaced by subbandgap light excitation (the photocurrent values from which the decay starts being equivalent). The results cannot be quantitatively explained by the effects of changing of the quasi-Fermi level position well known for DX-centers in AlGaAs. No persistent photoconductivity could be observed in high resistivity undoped AlGaN films with 5%, 15% and 25% of Al.

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