Low Frequency Fourier Transform Infrared (FTIR) Spectra Of Fluoroethanes

1981 ◽  
Author(s):  
V. F. Kalasinsky ◽  
H. V. Anjaria ◽  
T. S. Little
Keyword(s):  
Fourier Transform ◽  
Low Frequency ◽  
Fourier Transform Infrared ◽  
Ftir Spectra

scholarly journals Plaster Characterization at the PPNB Site of Yiftahel (Israel) Including the Use of 14C: Implications for Plaster Production, Preservation, and Dating

Radiocarbon ◽  
2012 ◽  
Vol 54 (3-4) ◽  
pp. 887-896 ◽  
Author(s):  
Kristin M Poduska ◽  
Lior Regev ◽  
Francesco Berna ◽  
Eugenia Mintz ◽  
Ianir Milevski ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Crystal Lattice ◽  
High Temperatures ◽  
Fourier Transform Infrared ◽  
Ftir Spectra ◽  
Stable Carbon ◽  
Calcite Crystal ◽  
Surface Layers ◽  
Ftir Microscopy ◽  
Fine Grained

The Pre-Pottery Neolithic B (PPNB) site of Yiftahel, Israel, contains abundant plaster floors. We surveyed the states of preservation of the plasters using an infrared spectroscopic assay that characterizes the extent of disorder of the atoms in the calcite crystal lattice. We identified the 3 best-preserved plaster samples that had disorder signatures most similar to modern plaster. We then studied the surface layers, fine-grained matrices, and large aggregates of these samples using micromorphology, Fourier transform infrared (FTIR) microscopy, stable carbon and radiocarbon concentrations. Even though some of the plaster components have a geogenic appearance in micromorphology slides and in FTIR spectra, the 14C analyses show that all components were exposed to high temperatures and as a result were equilibrated with the 14C content of the atmosphere ∼10,000 yr ago. This implies that the plasters at Yiftahel were produced entirely from heat-altered calcite. We also show that these plasters have undergone significant diagenesis. The plaster component with the most disordered atomic signature, and hence the most similar in this respect to modern plaster, did indeed produce a 14C date close to the expected age.

scholarly journals Partial Least Squares (PLS) Integrated Fourier Transform Infrared (FTIR) Approach for Prediction of Moisture in Transformer Oil and Lubricating Oil

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Siong Fong Sim ◽  
Amelia Laccy Jeffrey Kimura
Keyword(s):  
Fourier Transform ◽  
Least Squares ◽  
Partial Least Squares ◽  
Fourier Transform Infrared ◽  
Ftir Spectra ◽  
Transformer Oil ◽  
Lubricating Oil ◽  
Least Squares Regression ◽  
Promising Alternative ◽  
Karl Fischer

Fourier transform infrared (FTIR) spectroscopy has been advocating a promising alternative for Karl Fischer titration method for quantification of moisture in oil. This study aims to integrate partial least squares regression (PLSR) approach on FTIR spectra for prediction of moisture in locally accessible transformer oil and lubricating oil. The oil samples spiked with known moisture concentrations were extracted with acetonitrile and subjected to analysis with an FTIR spectrophotometer. The PLSR model was built based on 100 training/test splits, and the prediction performance was measured with the percentage root mean squares error (% RMSE). The range of concentration studied was between 0 and 5000 ppm. The marker region of moisture was found at 3750–3400 and 1700–1600 cm−1 with the latter demonstrating a better predictive ability in both lubricating oil and transformer oil. The prediction of moisture in lubricating oil was characterized with lower % RMSE. At concentration less than 700 ppm, the prediction accuracy deteriorates suggesting poor sensitivity. The PLSR was implemented on IR spectra of a set of blind samples, verified with Karl Fischer (for transformer oil) method and Kittiwake (for lubricating oil) method. The prediction was encouraging at concentrations above 1000 ppm; at lower concentrations, the prediction was characterized with high percent error. The algorithm, validated with 100 training/test splits, was converted into an executable program for prediction of moisture based on FTIR spectra. This program can be used for prediction of other substances given that the marker region is identified. FTIR can be used for prediction of moisture in oil nevertheless the sensitivity and precision is low for samples with low moisture concentration.

scholarly journals Fourier Transform Infrared Spectral Analysis of Polyisoprene of a Different Microstructure

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Dongmei Chen ◽  
Huafeng Shao ◽  
Wei Yao ◽  
Baochen Huang
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Spectral Analysis ◽  
Fourier Transform ◽  
Magnetic Resonance ◽  
Detailed Analysis ◽  
Fourier Transform Infrared ◽  
Ftir Spectra ◽  
H Nmr ◽  
Infrared Spectral

Some polyisoprene samples of different microstructure contents were studied by Fourier transform infrared (FTIR) and1H Nuclear magnetic resonance (1H NMR). On the basis of detailed analysis of FTIR spectra of polyisoprene, the shift of absorption peaks caused by microstructure content’s variation was discussed. The contents of the polyisoprene samples’ microstructure which was determined by the1H NMR was used as the standard. Through the choice, calculation, and comparison with the corresponding absorption peaks of FTIR, a method based on the results of the analysis has been developed for the determination of the microstructure contents of polyisoprene by FTIR.

scholarly journals Fourier transform infrared spectra of cells on glass coverslips. A further step in spectral pathology

The Analyst ◽  
2018 ◽  
Vol 143 (23) ◽  
pp. 5711-5717 ◽  
Author(s):  
A. V. Rutter ◽  
J. Crees ◽  
H. Wright ◽  
D. G. van Pittius ◽  
I. Yousef ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Infrared Spectra ◽  
Fourier Transform Infrared ◽  
Ftir Spectra ◽  
Fourier Transform Infrared Spectra

FTIR spectra of cells on glass coverslips allows the study of the Amide I region.

Fourier-Transform Infrared Spectroscopic Investigation of the Secondary Structure of P2 Protein in Deuterium Oxide Solution

1991 ◽  
Vol 44 (11) ◽  
pp. 1523 ◽  
Author(s):  
BH Stuart ◽  
EF Mcfarlane
Keyword(s):  
Fourier Transform ◽  
Secondary Structure ◽  
Deuterium Oxide ◽  
Resolution Enhancement ◽  
Low Frequency ◽  
Fourier Transform Infrared ◽  
Crystallographic Study ◽  
Fitting Procedures ◽  
P2 Protein ◽  
Α Helix

Fourier transform infrared ( F.t.i.r .) spectroscopy has been used to investigate the secondary structure of bovine P2 protein in deuterium oxide (D2O) solution. The amide 1 region of the spectrum was analysed quantitatively by means of resolution enhancement and band-fitting procedures. The protein was found to consist mainly of β-structure (61%), with a small amount of α-helix (11%). A reason for the existence of an unusually intense low-frequency band assigned to β-structure is discussed. The F.t.i.r . results are compared with those from an X-ray crystallographic study and from circular dichroism and explanations are offered for discrepancies between the results from the different methods.

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