Search results for "Spectroscopy"
showing 10 items of 10293 documents
Spectroscopic and chromatographic study of the interaction of nonionic micelles with the aluminum-morin complex
1989
Abstract The interaction of the aluminum-morin system with different nonionic surfactants has been studied spectrophotometrically and by high-performance liquid chromatography. It has been found that ethylene oxide-propylene oxide condensate surfactants sensitize the spectrophotometric determination of aluminum with morin more than ethylene oxide condensate surfactants. Binding ratio parameters for the different surfactants with free morin have been also estimated from the analysis of chromatographic vacant peaks.
Differentiation of isomeric cyclic diamides by electron impact mass spectra
1976
The behaviour under electron impact of two series of isomeric cyclopentane- and cyclohexane-1, 2- and -1, 3-dicarboxylic acid dipiperidides was studied. Diagnostic fragmentation pathways were found to differentiate the isomeric diamides. Additional evidence was obtained from the metastable transitions.
Terrylene in p-terphenyl: single-molecule experiments at room temperature
1999
Abstract This paper reports on fluorescence microscopy and spectroscopy of single terrylene molecules embedded in p -terphenyl at room temperature. The basic photophysical parameters of this crystalline host/guest system such as photostability, single-molecule emission rates and the properties of dispersed fluorescence spectra are reported. The stability of the single-molecule signals allowed the direct observation of singlet–triplet quantum jumps at room temperature, by means of which the underlying intersystem crossing rates can be investigated. The results of earlier investigations at liquid-helium temperatures are reviewed briefly where appropriate. The properties of terrylene in p -ter…
Specific dye adsorption at oriented monolayers
2007
We studied the adsorption of water soluble cyanine dyes (pseudoiso-cyanine and “stains-all”) to monomolecular layers of arachidic acid at the water-air interface in a Langmuir trough. Fluorescence microscopy was employed to on-line monitor the formation of J-aggregates upon adsorption. Large two-dimensional monodomain single crystals could be grown by this self-assembly process with optical properties reminiscent of those found and extensively studied for amphiphilic derivatives of the same chromophors [12]. In addition to the necessary Coulombic interaction between subphasedye and target monolayer, we found that details of the crystal morphology also crucially depend on substrate parameter…
Magneto-Transport Results in Alq3 Based OSVs
2015
The achievement of good magnetoresistance signal at room temperature is an important requirement for the possible future development of organic devices for applications. However, until now only few works reported room temperature MR effect in organic spin valves (OSVs). In this regard, this chapter is dedicated to the investigation of Alq3-based OSVs where Alq3 molecule was chosen since it is a standard material in the field. A systematic study on Co/Alq3/Co OSVs will be presented showing room temperature MR results. Moreover, inelastic electron tunneling spectroscopy (IETS) technique will be used to prove spin injection into the organic layer. Finally, an insulating oxide barrier (Al2O3 or…
Optical properties of lithium niobate single crystals
2005
Studies of thermal and γ-irradiation effects on the optical properties in congruous lithium niobate single crystals containing Y, Mg, Gd, B, and Zn dopants including samples with double dopants Y, Mg and Gd, Mg are reported. Formation of defects at irradiation and thermal treatment of the samples is explored by electron absorption spectra. Considerable increase of absorption with the dose of γ-radiation is observed at 500 nm. The changes of absorption examined under different conditions are explained by creation and destruction of Nb 4 + defects.
Simple New Method for the Preparation of La(IO<sub>3</sub>)<sub>3</sub> Nanoparticles
2020
We present a cost- and time-efficient method for the controlled preparation of single phase La(IO3)3 nanoparticles via a simple soft-chemical route which takes a matter of hours, thereby providing an alternative to the common hydrothermal method which takes days. Nanoparticles of pure &alpha;-La(IO3)3 and pure &delta;-La(IO3)3 were synthesised via the new method depending on the source of iodate ions, thereby demonstrating the versatility of the synthesis route. The crystal structure, nanoparticle size-dispersal and chemical composition were characterised via angle- and energy-dispersive powder X-ray diffraction, scanning electron microscopy and Fourier-transform infrared spectrosco…
Room-temperature ionic liquid-based electrochemical nanobiosensors
2012
Abstract Room-temperature ionic liquids (RTILs) have proved to be excellent materials for applications in electrochemistry. We review progress in constructing high-performance electrochemical biosensors. We also discuss: • different modified electrodes based on RTILs for biosensing applications; • different routes for enzyme biosensing based on RTIL-modified electrodes; • incorporation of biorecognition elements into RTIL-based electrodes; • electroanalytical applications of RTIL-based modified electrodes; and, • recent developments in which the advantages of ILs as a medium for biosensing were realized. We also summarize the latest developments in the applications of RTIL-based electrochem…
Rotational spectra of isotopic species of silyl fluoride. Part II: theoretical and empirical equilibrium structure
2010
Abstract The equilibrium structure of silyl fluoride, SiH 3 F, has been reinvestigated using both theoretical and experimental data. With respect to the former, quantum-chemical calculations at the coupled-cluster level have been employed together with extrapolation to the basis set limit, consideration of higher excitations in the cluster operator, and inclusion of core correlation as well as relativistic corrections ( r (Si–F) = 1.5911 A, r (Si–H) = 1.4695 A, and ∠FSiH = 108.30°). A semi-experimental equilibrium structure has been determined based on the available rotational constants for the various isotopic species of silyl fluoride ( 28 SiH 3 F, 28 SiD 3 F, 29 SiH 3 F, 29 SiD 3 F, 30 S…
<strong>QUANTITATIVE QUANTUM MECHANICAL NMR ANALYSIS: THE SUPERIOR TOOL FOR ANALYSIS OF BIOFLUIDS</strong>
2016
Almost automatic quantitative analysis of biofluids is now behind only a few clicks from sample to EXCEL table after minimal sample preparation (move 0.3 ml sample into NMR tube and add buffer), without separations, calibration and reference materials, even for unknown compounds! Each organic compound with protons gives a highly diagnostic and unique NMR spectrum which is practically identical with any spectrometer operating at certain field. A distinctive feature of high-resolution 1D NMR spectra is that even the most complex spectrum of a compound can be described by a few spectral parameters within experimental accuracy, employing a quantum mechanical theory. The NMR spectral parameters…