scholarly journals Determination of Acid Dissociation Constant of Methyl Red by Multi-Peaks Gaussian Fitting Method Based on UV-Visible Absorption Spectrum

2012 ◽  
Vol 28 (05) ◽  
pp. 1030-1036 ◽  
Author(s):  
ZHANG Jian-Hua ◽  
◽  
LIU Qiong ◽  
CHEN Yu-Miao ◽  
LIU Zhao-Qing ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Dissociation Constant ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Methyl Red ◽  
Visible Absorption Spectrum ◽  
Visible Absorption ◽  
Fitting Method ◽  
Uv Visible

Authentication and Analysis of Olive Oil Based on Stimulated Brillouin Scattering and UV-Visible Absorption Spectrum

2018 ◽  
Vol 45 (9) ◽  
pp. 0911016
Author(s):  
曹晨鹏 Cao Chenpeng ◽  
郝仕国 Hao Shiguo ◽  
罗宁宁 Luo Ningning ◽  
史久林 Shi Jiulin ◽  
何兴道 He Xingdao
Keyword(s):  
Absorption Spectrum ◽  
Olive Oil ◽  
Brillouin Scattering ◽  
Stimulated Brillouin Scattering ◽  
Visible Absorption Spectrum ◽  
Visible Absorption ◽  
Uv Visible ◽  
Stimulated Brillouin

scholarly journals Effect of Cu, Cr, S Doped TiO2 for Transparent Plastic Bar Reinforced Concrete

2020 ◽  
Vol 10 (20) ◽  
pp. 7334
Author(s):  
Seung-Hoon Seo ◽  
Byoung-Il Kim
Keyword(s):  
Absorption Spectrum ◽  
Reinforced Concrete ◽  
Visible Light ◽  
High Performance Concrete ◽  
Test Method ◽  
Visible Absorption Spectrum ◽  
Nox Removal ◽  
Transparent Plastic ◽  
Visible Absorption ◽  
Uv Visible

In this study, after firing and powdering Cu, Cr, and S with NP-400 TiO2, an NOx removal rate test was performed according to the ISO test method to analyze the photocatalytic reactivity in visible light. The distribution of the photocatalyst and visible light reactivity on the surface of the test specimen were confirmed through SEM (Scanning electron microscope), EDS (Energy dispersive spectroscopy), XRD (X-ray diffraction), UV-visible absorption spectrum and energy band gap tests. The flowability of UHPC (Ultra high performance concrete) slightly decreased due to the increase in the photocatalyst mixing rate, but both J-Ring and L-Box test results showed that there is no problem when concrete is placed. As a result of SEM and EDS tests, good microstructure and peak values were confirmed in the test specimens doped with Cu, and as a result of the XRD test, anatase and rutile peaks were confirmed in the Cu, Cr, and S specimens. In the UV-visible absorption spectrum analysis, it was confirmed that only the specimen doped with Cu maintains a high absorption power of 0.8 up to 700 nm, and the inherent band gaps are reduced to 2.9 eV, thereby increasing the possibility of reaction in visible light. Finally, as a result of the NOx removal test by the ISO test method, about 15.8% was removed for 5 h in the specimen doped with Cu, and the removal efficiency is estimated to be possible up to about 25% when applied with the TPBRC (transparent plastic bar reinforced concrete).

Chromatographic Determination of Thermodynamic Acid Dissociation Constants of Tetracycline Antibiotics and Their Epimers

2019 ◽  
Vol 57 (8) ◽  
pp. 745-750
Author(s):  
İlkay Konçe ◽  
Ebru Çubuk Demiralay ◽  
Hülya Yılmaz Ortak
Keyword(s):  
Experimental Data ◽  
Dissociation Constant ◽  
Binary Mixtures ◽  
Dissociation Constants ◽  
Reversed Phase ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Chromatography Method ◽  
Ph Values

Abstract The presented study describes the development of reversed-phase liquid chromatography method using a core-shell particle column with a pentafluorophenyl stationary phase for the dissociation constant (pKa) determination of the tetracycline group antibiotics (tetracycline, oxytetracycline, chlortetracycline) and their epimers (4-epitetracycline, 4-epioxytetracycline, 4-epichlortetracycline). The pH values were measured in the acetonitrile (ACN)–water binary mixtures, used as mobile phases, instead of in water and take into account the effect of the activity coefficients. Thermodynamic acid dissociation constant (pKa1) values of studied antibiotics and their epimers were calculated using retention factor (k) at different mobile phase pH values in studied binary mixtures with ACN percentages of 20, 25, 30 and 35% (v/v). Experimental data were analyzed by using an Origin 7.0 program to fit experimental data to the nonlinear expression derived. From calculated pKa1 values, the aqueous pKa values of studied compounds were calculated by different approaches and these values were compared.

ChemInform Abstract: CHEMISTRY OF ANTHOCYANIN PIGMENTS. 4. UV-VISIBLE ABSORPTION SPECTRUM OF THE CHALCONE FORM OF MALVIDIN 3-GLUCOSIDE

1979 ◽  
Vol 10 (34) ◽  
Author(s):  
R. BROUILLARD ◽  
B. DELAPORTE ◽  
J. M. EL HAGE CHAHINE ◽  
J. E. DUBOIS
Keyword(s):  
Absorption Spectrum ◽  
Visible Absorption Spectrum ◽  
Visible Absorption ◽  
Uv Visible ◽  
Anthocyanin Pigments

The UV-visible absorption spectrum of methylglyoxal

1991 ◽  
Vol 62 (2) ◽  
pp. 163-171 ◽  
Author(s):  
R. Meller ◽  
W. Raber ◽  
J.N. Crowley ◽  
M.E. Jenkin ◽  
G.K. Moortgat
Keyword(s):  
Absorption Spectrum ◽  
Visible Absorption Spectrum ◽  
Visible Absorption ◽  
Uv Visible
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