scholarly journals Product study and mechanisms of the reactions of α-pinene and of pinonaldehyde with OH radicals

1999 ◽  
Vol 104 (D19) ◽  
pp. 23645-23656 ◽  
Author(s):  
Barbara Nozière ◽  
Ian Barnes ◽  
Karl-Heinz Becker
Keyword(s):  
Oh Radicals ◽  
Product Study

Product Study of the Reaction of CH3with OH Radicals at Low Pressures and Temperatures of 300 and 612 K†

2005 ◽  
Vol 109 (17) ◽  
pp. 8415-8427 ◽  
Author(s):  
Christopher Fockenberg ◽  
Ralph E. Weston, ◽  
James T. Muckerman
Keyword(s):  
Oh Radicals ◽  
Low Pressures ◽  
Product Study

Product study of the reaction of OH radicals with isoprene in the atmosphere simulation chamber SAPHIR

2006 ◽  
Vol 55 (2) ◽  
pp. 167-187 ◽  
Author(s):  
M. Karl ◽  
H.-P. Dorn ◽  
F. Holland ◽  
R. Koppmann ◽  
D. Poppe ◽  
...  
Keyword(s):  
Oh Radicals ◽  
Atmosphere Simulation Chamber ◽  
Product Study ◽  
Simulation Chamber

Hydroxyl Radical-Induced Oxidation of Ethanol in Oxygenated Aqueous Solutions. A Pulse Radiolysis and Product Study

1983 ◽  
Vol 38 (2) ◽  
pp. 212-219 ◽  
Author(s):  
Eberhard Bothe ◽  
Man Nien Schuchmann ◽  
Dietrich Schulte-Frohlinde ◽  
Clemens von Sonntag
Keyword(s):  
Acetic Acid ◽  
High Dose Rate ◽  
Peroxyl Radicals ◽  
High Dose ◽  
Oh Radicals ◽  
Order Kinetic ◽  
Solvent Cage ◽  
Saturated Water ◽  
C 50 ◽  
Product Study

Abstract γ-Radiolysis of N2O-saturated water or photolysis of aqueous H2O2 provided a source of OH radicals. These radicals react with ethanol by preferentially abstracting an H atom at C-1. In the presence of oxygen these radicals are converted into the corresponding peroxyl radicals.The a-hydroxyethylperoxyl radicals decay by first order kinetic(k=k1 + k2 [OH-]) acetaldehyde and HO2˙/H+ + O2 ⨪ being the products (k1 (20 °C) = 50 ± 10 s-1 , Ea = 66 ± 7 kJ·mol-1 , k2= (4± 1) X 109 M-1 s-1). In competition (favoured by low pH, low temperature and high dose rate) they also decay by second order kinetics (2k3 = (7 ± 2) x 108 M-1 s-1). The most important route in the bimolecular decay leads to acetaldehyde, acetic acid and oxygen (ca. 75%). This route might largely be concerted (Russell mechanism), but there might also be a contribution from the disproportionation of oxyl radicals within the solvent cage. There is also a concerted route that leads to two molecules of acetic acid and to hydrogen peroxide (ca. 10%). Another pathway (ca. 15%) yields two oxyl radicals and oxygen. The former may either decompose into formic acid and methyl radicals (ca. 5%) or rearrange into 1,1-dihydroxyethyl radicals (ca. 10%). These radicals add oxygen and the resulting peroxyl radicals rapidly decompose into acetic acid and HO2˙. The reaction of a-hydroxyethylperoxyl radicals with HO2˙/O2⨪ radicals appears to be slow (k≈107 M-1s-1).

Synthesis of HTCMgFe for the degradation of indigo carmine through heterogeneous photo-Fenton treatment

MRS Advances ◽  
2020 ◽  
Vol 5 (62) ◽  
pp. 3273-3282
Author(s):  
I. Cosme-Torres ◽  
M.G. Macedo-Miranda ◽  
S.M. Martinez-Gallegos ◽  
J.C. González-Juárez ◽  
G. Roa-Morales ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Treatment Time ◽  
Uv Light ◽  
Indigo Carmine ◽  
Oh Radicals ◽  
Absorption Bands ◽  
Chromophore Group ◽  
X Ray ◽  
Catalytic Sites ◽  
Scanning Electron

AbstractThe heterogeneous catalyst HTCMgFe was used in the degradation of the IC, through the heterogeneous photo-fenton treatment, this material in combination with H2O2 and UV light degraded the dye in 30 min at pH 3. As the amount of HTCMgFe increases the degradation it was accelerated because there are more active catalytic sites of Fe2+ on the surface of the material, which generates a greater amount of •OH radicals. The HTCMgFe was characterized by infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray energy dispersive elemental analysis (EDS). The UV-vis spectrum shows that the absorption bands belonging to the chromophore group of the IC disappear as the treatment time passes, indicating the degradation of the dye.

Effect of Pre-Tension on the Springback Behavior of the Yellow Brass

2020 ◽  
Vol 38 (4A) ◽  
pp. 552-560
Author(s):  
Anwar H. Zabon ◽  
Aseel H. Abed
Keyword(s):  
Rolling Direction ◽  
Total Strain ◽  
Deformation Velocity ◽  
Constant Deformation ◽  
Springback Behavior ◽  
Product Study

Springback forecasting of sheet formation is constantly remarkable problem in the métier, due to their influence the great in the definitive shape of the product. Study presents effects of pretension in tow rolling direction (0, 45 degree) on the springback behavior of the (Brass 65-35) sheet under V-die bending by an experimental. The pretension ranges from five different pretensions levels starting from 11% to 55% from total strain in each rolling direction by increment of 11%. used in punching that was performed at a constant deformation velocity of (5 mm/min) then bent on a 90° V-shaped die for the springback evaluation. The results from experiment indicate that the springback increase with pretension ratio and the springback in 45 degree is higher in rolling direction.

Photo-catalytic Study of Malachite Green Dye Degradation Using Rice Straw Extracted Activated Carbon Supported ZnO Nano-particles

2020 ◽  
Vol 10 (6) ◽  
pp. 849-859
Author(s):  
Radwa A. El-Salamony ◽  
Abeer A. Emam ◽  
Nagwa A. Badawy ◽  
Sara F. El-Morsi
Keyword(s):  
Activated Carbon ◽  
Visible Light ◽  
Rice Straw ◽  
Malachite Green ◽  
Dye Degradation ◽  
Nano Particles ◽  
Oh Radicals ◽  
Impregnation Method ◽  
Photo Degradation ◽  
Malachite Green Dye

Objective: ZnO nanoparticles were synthesized using wet impregnation method, and activated carbon from rice straw (RS) prepared through chemical route. Methods: The nano-composites ZnO-AC series were prepared with different ZnO:AC ratio of 10, 20, 50, and 70% to optimize the zinc oxide nanoparticles used. The obtained composites were characterized by FE-SEM, XRD, SBET, and optical techniques then used for the photo-degradation of Malachite green dye (MG) under visible light. Results: It was found that 10ZnO-AC exhibited excellent visible light photo-catalytic performance. The ·OH radicals’ formation is matching with photo-activity of the prepared composites. The photo-degradation efficiency of MG increased from 63% to 93%, when the 10ZnO-AC photocatalyst amount was increased from 0.5 to 6 g/L. Conclusion: The GC-MS technique was used to analyze the intermediates formed; up to 15 kinds of chemicals were identified as the degradation products.

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