Search Results

You are looking at 1 - 10 of 345 items for :

  • "IR-spectroscopy" x
  • Refine by Access: All Content x
Clear All

Abstract  

Adsorption of the herbicide terbuthylazine by a soil from the Jezreel Valley was investigated by thermo-IR-spectroscopy. The adsorption took place mainly by the clay mineral montmorillonite. The adsorbed molecule was hydrogen bonded via the aniline groups to water molecules which were coordinated to the exchangeable metallic cations. When the sample was thermally treated at 115°C interlayer water was evolved, part of the herbicide decomposed and the other part became directly coordinated to the exchangeable metallic cations. The decomposition product contained a CO group.

Restricted access

. Günzler H Gremlich HU . IR spectroscopy . Weinheim : Wiley-VCH ; 2002 . 23. Ma X

Restricted access

formed during the calcination of sulfur-rich calcareous oil shales from the Negev deposits were analyzed using FT-IR spectroscopy and curve-fitting technique. These techniques allow the identification of individual thermal phases [ 10

Restricted access

useful in controlling quality changes in food during processing and in storage [ 10 , 11 ]. IR spectroscopy, on the other hand, serves as an established method to determine types and number of chemical bonds present in a sample and therefore it can be

Restricted access

Summary The reaction of a hydrated nitrate salt of lanthanide (Ln=Pr, Nd, Gd, Dy, Er) with the polyfunctional ligand salicylhydroxamic acid (H3sha), in the presence of base, afforded solid compounds, insoluble in common organic solvents and in water. The new complexes characterized by means of elemental analyses (C, H, N, Ln), magnetic moment determinations and spectroscopic data (IR, MS). It is proposed that they are neutral, with a possible polymeric structure of the general type: [Ln2(Hsha)2(H2sha)(DMF)x(CH3O)(H2O)]n×2H2O Their thermal decomposition was studied in nitrogen and/or oxygen atmosphere, between 25-1000°C by using simultaneous TG/DTG-DTA technique. The IR spectroscopy used to determine the intermediates and the final products. The intermediates at 180°C suggest the formation of N-hydroxylactam complex, which upon further heating gives a carbonaceous residue of Ln2O3 at 1000°C in nitrogen, while in oxygen the stable oxides are formed at 600°C.

Restricted access

Abstract  

The quartz-cristobalite transformation in heated natural chert (flint) rock composed of micro- and ŗypto-quartz was investigated in the temperature interval of 1000–1300°C by micro-Raman spectroscopy, FT-IR spectroscopy, X-ray diffraction and Scanning Electron Microscopy. A small amount of crystobalite was first observed in the chert after heating at 1000°C for 1 h and the transformation was almost completed after heating at 1300°C for 24 h. On the other hand, cristobalite was not detected in well-crystallized pure quartz after heating under the same conditions. The transformation occurs as a solid state nucleation and crystal growth of cristobalite replacing quartz at high-temperatures. The chert rock is naturally rich in crystal defects and boundaries which serve as nucleation sites and enable an earlier quartz-cristobalite transformation.

Restricted access

FT-IR spectra of various pectin preparations extracted from press cakes of red and black currant, raspberry and blackberry have shown structural differences. Based on the spectra data degree of esterification (DE) of the pectins was determined and found to be in the range of 50–65.

Restricted access

wish to thank the Slovak Grant Agency (KEGA: 002 TnUAD 4/2011) for the financial support. References 1. Yariv , S 1996 Thermo-IR spectroscopy analysis

Restricted access