Extrapolation method for determination of extinction coefficients of free radical anions and di-anions in ether solution

1968 ◽  
Vol 64 ◽  
pp. 2586 ◽  
Author(s):  
J. G. Broadhurst ◽  
J. C. Chippendale ◽  
E. Warhurst
Keyword(s):  
Free Radical ◽  
Extrapolation Method ◽  
Radical Anions ◽  
Extinction Coefficients ◽  
Ether Solution

Free-radical reductions of arenediazonium ions in aqueous solution. V. Pulse-radiolytic determination of rate constants for some para-substitutedbenzenediazonium ions

1981 ◽  
Vol 34 (7) ◽  
pp. 1433 ◽  
Author(s):  
JE Packer ◽  
J Monig ◽  
BC Dobson
Keyword(s):  
Aqueous Solution ◽  
Free Radical ◽  
Rate Constants ◽  
Substituent Effect ◽  
Reduction Potential ◽  
Radical Anions ◽  
Semiquinone Radical ◽  
Substituent Group

Some rate constants for the reduction of para-substituted benzenediazonium ions by the radicals eaq-, ·CH2OH, (CH3)2·COH and some semiquinone radical anions have been measured. The substituent group has no effect on the rates with eaq-, but as the reduction potential of the reducing radical becomes more positive, the substituent effect increases, electron-withdrawing groups enhancing the rates. No free halide is formed on reduction of p-BrC6H4N2+ or p-IC6H4N2+ by eaq- or ·CH2OH.

scholarly journals A spectrophotometric method for determination of fluorophore-to-protein ratios in conjugates of the blue fluorophore 7-amino-4-methylcoumarin-3-acetic acid (AMCA)

1990 ◽  
Vol 38 (1) ◽  
pp. 87-94 ◽  
Author(s):  
M W Wessendorf ◽  
S J Tallaksen-Greene ◽  
R M Wohlhueter
Keyword(s):  
Acetic Acid ◽  
Optical Density ◽  
Extinction Coefficient ◽  
Spectrophotometric Method ◽  
Extinction Coefficients ◽  
Beer's Law ◽  
Beer’S Law ◽  
The Given

7-Amino-4-methylcoumarin-3-acetic acid (AMCA) has been found to be a useful fluorophore for immunofluorescence. The present study describes a spectrophotometric method for determining the ratio of moles AMCA to moles protein (or the f/p ratio) in an AMCA-conjugated IgG. The concentration of a substance absorbing light can be determined spectrophotometrically using Beer's Law: Absorbance = Concentration x Extinction coefficient. From Beer's law, one can derive the following formula for determining the f/p ratio of AMCA-IgG conjugates: f/p = (epsilon 280IgG).A350 - (epsilon 350IgG).A280/(epsilon 350AMCA).A280 - (epsilon 280AMCA).A350 where A is the optical density of the conjugate at the given wavelength and epsilon is the extinction coefficient of a substance at the wavelength specified. Using conjugates of model proteins, it was found that the extinction coefficients of the AMCA moiety of AMCA-conjugated protein were 1.90 x 10(4) at 350 nm and 8.29 x 10(3) at 280 nm. Similarly, it was found that the extinction coefficients of swine IgG were 1.56 x 10(3) at 350 nm and 1.26 x 10(5) at 280 nm. Thus, for AMCA-conjugated swine IgG: f/p = (1.26 x 10(5)).A350 - (1.56 x 10(3)).A280/(1.47 x 10(4)).A280 - (6.42 x 10(3)).A350 [corrected]. Based on this formula, the f/p ratios of some AMCA-IgG conjugates useful for immunohistochemistry have been found to range between 6 and 24.

Load Spectrum Compilation Based on Nonparametric Statistical Extrapolation

2013 ◽  
Vol 694-697 ◽  
pp. 271-277 ◽  
Author(s):  
Zhi Qiang Xu ◽  
Hong Jian Wang ◽  
Ming Yao Yao
Keyword(s):  
Kernel Function ◽  
Time History ◽  
Critical Issue ◽  
Extrapolation Method ◽  
Load History ◽  
Load Spectrum ◽  
Load Characteristics ◽  
Nonparametric Statistical ◽  
Function Shape

Considering the special load characteristics of the wheel loader, thispaper focus on compiling the load spectrum of the transmission of the wheelloader using the nonparametric statistical extrapolation method (NSEM). In thisprocess, the determination of the kernel function shape is the critical issue,which has been discussed in detail. Before extrapolating the sample loadspectrum, the signal denoising of the field-tested time-history load signals isperformed. After that, the sample load cycles are obtained using the rainflowcounting method and the corresponding kernel function shape is determined. Thenthe NSEM of rainflow matrix is proposed, by which the whole-life load spectrumis estimated. The proposed extrapolation method can well realize the estimationof the load cycles that do not appear in sample load cycles but may exist inthe whole-life load history.

Diiodo Acetals and Unsaturated Lactones From Dihydropyran

1993 ◽  
Vol 46 (2) ◽  
pp. 203 ◽  
Author(s):  
MJ Lynch ◽  
J Simpson ◽  
RT Weavers
Keyword(s):  
Free Radical ◽  
X Ray ◽  
Ester Formation ◽  
Propiolic Acid ◽  
Unsaturated Lactones ◽  
By Products

Reaction of dihydropyran with propiolic acid and N- iodosuccinimide gave an iodo ester which was cyclized under free-radical conditions to form an (E) iodomethylene lactone. Photolysis of this lactone could be controlled to generate mixtures of (E) and (Z) iodomethylene lactones, or alternatively the iodine-free methylene lactone. The structures of some by-products of the iodo ester formation have been shown to be a succinimide derivative and two stereoisomers of a diiodo acetal. X-Ray determination of the structure of one of the diiodo acetal isomers is described.

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