Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 49 for “"visible absorption"”.
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Ultraviolet and visible absorption spectra of potassium and potassium-xenon mixtures
The visible absorption spectrum of the potassium dimer has been studied using a new type of optical cell designed specifically for the alkali vapors or alkali-rare gas mixtures. Particular emphasis has been placed on examining the diffuse K2 bands lying at 722 nm, 575 nm, 478 nm and 402 nm. …
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Forensic Application of Chemometric Analysis to Visible Absorption Spectra Collected from Dyed Textile Fibers
… a statistical method of analysis for comparing visible absorption profiles collected from highly similarly colored textile fibers via microspectrophotometry (MSP). Several chemometric techniques were applied to spectral data and utilized to help discriminate fibers beyond the point where …
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Thermodynamic and Spectroscopic Studies of Some Metal Dimers
… of calorimetry, epr spectroscopy, and uv-visible absorption spectroscopy.
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Spectroscopic studies of hydrophobic association of merocyanine dyes in cationic and anionic micelles
… dyes exhibit interesting changes in absorption spectra with changes in solvent polarity. For example solutions of 1-methyl-4- (oxocyclohexadienylidene) ethylidene -1,4-dihydropyridine (MOED) are yellow, red, violet, or blue, in water, ethanol, acetone or pyridine …
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The Free Radical Nature of Compound I From Horseradish Peroxidase and Chloroperoxidase
… Peroxidase. The Compound Is were analyzed by visible absorption, electron paramagnetic resonance (EPR), Mossbauer and electron nuclear double resonance (ENDOR) spectra. These spectral techniques were used to prove that one of the two oxidation equivalents associated with Compound I consists of …
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Large-area CVD growth of two-dimensional transition metal dichalcogenides and monolayer MoS₂ and WS₂ metal-oxide-semiconductor field-effect transistors
… materials, including photoluminescence, UV-visible absorption, Raman spectroscopy, X-ray photoelectron spectroscopy, and atomic force microscopy. Moreover, the electronic transport characteristics of single-layer CVD-grown MoS₂ and WS₂ field-effect transistors with a back-gated configuration …
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The Synthesis of Core-Shell Iron@Gold Nanoparticles and Their Characterization
… Device), TGA (Thermograviometric analysis), UV-visible absorption spectroscopy and Faraday rotation were employed to characterize the morphology, structure, composition and magnetic properties of the products. HRTEM images show clear core-shell structure with different crystal lattices from Fe …
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The chemistry of some polysubstituted derivatives of di - and triphenylmethane dyes
… ring have been synthesised and their respective visible absorption spectra compared with that of Malachite Green. In most cases where steric effects are unimportant an additive relationship is found between the electronic effects of the substitüents and the position of the first frequency …
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Antioxidant activity of Mn-salophen complex and its effects on antioxidant enzymes in Escherichia coli
… acetate dihydrate and salophen in ethanol. Visible absorption spectrum of the red-brown solution exhibited a broad absorption band at 430 - 450 nm with two shoulders between 500 and 600 nm which were absent with either salophen or manganic acetate alone. Titration of salophen with …
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C2- and C3-Symmetric Meta-substituted Thienyl Benzenes: A Comparative Synthetic and Structural Study
… compounds are compared using spectroscopic (UV-visible absorption and fluorescence) and electrochemical measurements. The anodic peak potentials (Epa) obtained for these compounds do not correlate with their σm Hammett parameters.
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Towards Direct Writing Of 3-d Photonic Circuits Using Ultrafast Lasers
… are described using a free electron model. UV/visible absorption spectroscopy, photoluminescence spectroscopy and Raman spectroscopy are used to assess the changes occurring at the atomic level. Finally, the impact of laser direct writing on nonlinear waveguide applications is discussed.
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Morphology and Conformation of Polythiophene Derivatives in Anisotropic Core-Shell Nanocomposites and Solution
… dilute solution through the use of ultraviolet-visible absorption spectrophotometry. A coil-to-rod conformational transition is identified, and is found to be induceable through temperature and solvent changes. Study into the kinetics of the transition reveals a first-order rate law, and the …
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Pressure Tuning Spectroscopy of Metal Cluster Compounds and Organometallics
… was studied through the use of electronic absorption and infrared spectroscopies. The systems studied were chosen for their use as potential models for chemisorbed metallic surfaces, and to gain a better fundamental understanding of metal-carbon interactions. In particular, it was found …
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Alkyl, alkenyl and cycloalkyl substituted triphenylmethane dyes
… positions has been synthesised. Their respective visible absorption spectra have been correlated with the electronic and steric effects of the methyl, ethyl, propyl, butyl and vinyl substituents in the phenyl ring. The linear relationship between the wavelength of maximum absorption for the x-band …
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The chemistry of some triphenylmethane dyes
… electronic effects of the substituents on the visible absorption spectra of the dyes have been examined and linear correlations between A max and appropriate Hammett substituent constants have been established. The rates of hydrolysis of the 4-diethylamino substituted analogue of Pyrrole Green …
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Structural and spectroscopic studies with dithizone and its derivatives
… measurements. The temporal changes in the visible absorption spectrum of S-methyldithizone, PhN:N•C(SCH3):N•NHPh, have been shown to arise from syn-anti isomerization about the fonnal C=N double bond and rotation about the C-N single bond by considering the evidence provided by i. r. and …
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Spectroscopic Technologies and Computational Approaches for Real-Time Detection of FMN as Biomarker during Machine Perfusion
… are based on spectrophotometric measurements, UV-visible absorption, and fluorescence, using both standard laboratory instruments, such as benchtop spectrophotometers, and an innovative stand-alone device, specifically developed by the company funding the doctoral research, capable of detecting …
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Desenvolvimento de um sistema terapêutico emulsionado para uso oral a base de óleo de rã-touro (Rana catesbeiana Shaw)
… significant changes in the ultraviolet visible absorption spectrum and infrared were observed. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) showed that the oil was stable up to 200 °C.
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Characterisation of Rhodopsin Retinitis Pigmentosa mutants located in Intradiscal Loop 1
… have been analysed by investigating their UV-visible absorption spectral properties, photobleaching properties, active light-activated state stability kinetics and pigment thermal stability. Pharmacological chaperone rescue with 9-cis-retinal was found to enhance expression levels and folding …
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The chemistry of some heterocyclic analogues of triphenylmethane dyes
… nitrogen, oxygen or sulphur as hetetâacoins. The visible absorption spectra of the dyes have been correlated with the electronic and structural features of the molecules. Novel analogues of Malachite Green have been prepared containing terminal pyrrolidine and N-methylpiperazine groups. …
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