In situ Raman spectra of chemisorbed azobenzene (AB) monolayers on glassy carbon (GC) electrodes were observed under potentiostatic conditions in acetonitrile (ACN) with tetrabutyl-ammonium tetrafluoroborate (TBA-BF4). The Raman intensities of these spectra were high below -1000 mV, and this is attributed to the change in absorbance of AB on GC. In this paper, we describe chemisorbed AB molecul...

Instruments. NMR spectra were obtained with Bruker AC-300 and Varian UNITY-500 spectrometers. Mass spectra were obtained with Perkin Elmer Sciex API 365 electrospray ionization (ESI) and Bruker Biflex III matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) instruments at the University of Wisconsin Biotechnology Center. Ultraviolet and visible absorbance was recorded with a C...

The present study focused on the synthesis of silver nanoparticles using the aqueous extract of Ulva flexousa (green seaweed). Ten ml of the aqueous extract of alga was mixed with 90 ml of 1mM aqueous AgNO3 solution for reducing of Ag+ ions. The synthesized silver nanoparticles were characterized by UV-Vis spectra, XRD (X-ray diffraction), TEM (Transmission electron microscopy) and FT-IR (Fouri...

the complex formation reaction between iodine with tetrabutylammonium halides (tbax) has been studied spectrophotometrically in chloroform solution at 25ºc. various aspects of the spectra of iodine in the presence of various concentration of different tetrabutylammonium halides have been discussed in terms of electronic specifications of iodine and halides. in the case of tetrabutylammonium iod...

This paper studies the application of principal component analysis, multiple polynomial regression, and artificial neural network ANN techniques to the quantitative analysis of binary mixture of dye solution. The binary mixtures of three textile dyes including blue, red and yellow colors were analyzed by PCA-Multiple polynomial Regression and PCA-Artificial Neural network PCA-ANN methods. The o...

The equilibrium reactions of the metallochromic indicator dye Antipyrylazo III with calcium at physiological ionic strength have been investigated spectrophotometrically. Dye absorbance as a function of wavelength was measured at various total dye and calcium concentrations. Analysis of the absorbance spectra indicated that at pH 6.9 at least three calcium:dye complexes form, with 1:1, 1:2, and...

Evaluation of the variations in spectra of the amylose-iodine complex of starches and amyloses from various botanical sources provide a useful aid for identification and characterization of these substances. Variations in absorptivity, wavelengths of maximum absorbance, and the slopes of the absorbance peaks provide characteristic data for starches as a result of variations in amylose molecular...

Transparent bubble free phosphate glasses with composition 50P2O5-10Al2O3-20CaO-(20-x)Na2O-xCeO2 (x varying from 0 to 4 mol %) have been prepared using melt quenching technique. The amorphous nature of the prepared glass samples has been confirmed from XRD spectra. The optical absorption coefficient has been determined from the UVvisible absorption spectra. The prepared glass samples have been ...

UNLABELLED In this work we present a detailed study on the influence of surface modifications for luminescent silver (Ag) clusters. Ag clusters (25 atoms) capped with dihydrolipoic acid show a distinct absorbance spectrum with several sharp transitions, and relative broad deep red luminescence with a quantum yield of 5% combined with a remarkably long luminescence lifetime of ~3 μs at room temp...

Two computer programs were designed for helping in library handling and microbial identification by means of their infrared spectra. The program 'Transform' runs in the IR Data Manager environment and produces ASCII files containing transformed data from infrared absorbance spectra. The program 'WinSpectra' is written in Visual Basic v. 3.0. It imports the ASCII files created with 'Transform', ...