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R.N. Jones

Bio: R.N. Jones is an academic researcher from National Research Council. The author has contributed to research in topics: Distortion & Infrared spectroscopy. The author has an hindex of 10, co-authored 11 publications receiving 631 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, the authors observed that unsaturated lactones exhibit two bands in the region of the spectrum associated with the C=O stretching vibrational mode, which is observed both in the infrared and Raman spectra.
Abstract: Certain types of unsaturated lactones exhibit two bands in the region of the spectrum associated with the C=O stretching vibrational mode. This is observed both in the infrared and Raman spectra.Th...

158 citations

Journal ArticleDOI
TL;DR: In this paper, a method is described for their evaluation and elimination, which yields a corrected absorption spectrum in units of absorption index and also a refractive index spectrum (dispersion curve), so that both optical constants are derived at all points across the spectrum.

90 citations

Journal ArticleDOI
TL;DR: In this paper, a method for determining the wedge effect in the cell cavity and for the measurement of the transmission when such wedge shaped cells are used in convergent radiation beams is described.

79 citations

Journal ArticleDOI
TL;DR: In this article, a computer-aided technique is described which eliminates much of the finite slit distortion from infrared spectra of condensed phase systems, which works best for band systems with peak absorbances in the range 2-09 and slit width to half-band width ratios below 035.

67 citations

Journal ArticleDOI
TL;DR: In this paper, the authors used single-pass and double-pass prism spectrometers of conventional design to measure the extinction coefficients of the principal absorption bands in the spectra of the homologous series of n-paraffin hydrocarbons from hexane to hexatriacontane.

65 citations


Cited by
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Journal ArticleDOI
02 Dec 1966-Science
TL;DR: A crystalline germination stimulant for the rootparasite, witchweed (Striga lutea Lour.), has been isolated from cotton rootexudates and characterized as a C19H22O6 compound, although apparently different from known plant hormones.
Abstract: A crystalline germination stimulant (trivial name strigol) for the rootparasite, witchweed (Striga lutea Lour.), has been isolated from cotton rootexudates and characterized as a C(19)H(22)O(6) compound. Although apparently different from known plant hormones, the stimulant is active at hormonal levels, causing germination at concentrations less than 1O(-5) part per million.

818 citations

Journal ArticleDOI
TL;DR: In this article, a vibrational and attendant conformational analysis of the liquid n-paraffins and molten polyethylene is presented, and a valence force field is derived which is applicable to both planar and nonplanar chains.
Abstract: A vibrational and attendant conformational analysis of the liquid n‐paraffins and molten polyethylene is presented. For the purposes of the analysis a valence force field was derived which is applicable to both planar and nonplanar chains. The force field was evaluated from observed frequencies of trans (T) and gauche (G) n‐C4H10; TT and GT n‐C5H12; TTT, GTT, and TGT n‐C6H14; and (T)∞ polyethylene, all of whose infrared spectra were assigned in detail. Infrared spectra of the liquid‐n‐paraffins n‐C4H10 through n‐C17H36 were measured at room temperature and n‐C4H10 through n‐C12H26 also at a temperature just above their melting point. Frequencies and normal coordinates were calculated for the extended forms and for forms having one gauche bond of n‐C4H10 through n‐C8H18. These quantities were also calculated for the conformations of n‐C5H12 through n‐C7H16 having two gauche bonds and for the nonplanar but regular conformations (TG)∞ and (G)∞ of polyethylene. Some bands attributable to forms of n‐C5H12 and ...

717 citations

Journal ArticleDOI
TL;DR: In this article, Fourier transform infrared absorption spectroscopy has been used to characterize the structure of porous silica gel films, both deposited on c-Si substrates and free standing.
Abstract: Fourier transform infrared absorption spectroscopy has been utilized to characterize the structure of porous silica gel films, both deposited on c‐Si substrates and free standing. The films were either dried at room temperature or subjected to partial densification at 400–450 °C. The spectra of the gel films are compared to those of thermal SiO2 grown on c‐Si and to Kramers–Kronig analysis of the reflection spectra of bulk SiO2 gels and v‐SiO2. The gel films show small frequency shifts compared to the latter spectra and they also exhibit new bands due to the presence of OH groups, although very little molecular water or residual organic species were found. The results are interpreted in terms of the gel structure. Compared to the thermal oxide, the sharp peak near 1070 cm−1 is narrower for the gels and the spread in intertetrahedral angles is estimated at 24° and 27° for room temperature dried and partially densified gels, respectively, compared to 33° for the thermal oxide. This is in agreement with a st...

410 citations

Journal ArticleDOI
William F. Maddams1
TL;DR: In this paper, a review of the various factors involved in curve fitting of vibrational band systems is presented, with particular reference to vibrational bands, and other types of overlapping band systems encountered in analytical work are considered in less detail.
Abstract: There is an increasing awareness that the separation of over-lapping bands by the mathematical technique of curve fitting offers many pitfalls and should not be undertaken lightly. This review discusses critically the various factors involved, with particular reference to vibrational band systems; other types of overlapping band systems encountered in analytical work are considered in less detail. Five parameters are involved: the number of component bands, their positions, shapes and widths, and the form of the baseline. Curve fitting, by a least squares optimization method to a suitable goodness of fit criterion, is considerably facilitated if approximate values for some of the parameters are known at the outset. The methods available for peak finding are discussed and, although not free from problems, are reasonably effective. Similarly, band shapes can usually be defined semiquantitatively. However, it is seldom possible to obtain prior information on band widths; these should be determined during the curve fitting calculations. Although statistical goodness of fit criteria are available they should be used in conjunction with a visual plot, to locate any regions of poor fit. Furthermore, the overriding consideration must always be that the computer fit is plausible in terms of acceptable chemical species for the system being examined.

355 citations

Journal ArticleDOI
Hans R. Zelsmann1
TL;DR: In this paper, the optical constants n and k of liquid H 2 O and D 2 O were calculated by iteration using the Kramers-Kronig transformation which has been adapted to the problem of fringe correction for a flat absorbing sample in contact with highly refractive silicon substrates.

337 citations