The spectrum of fluorine (FI)

The investigations of the spectrum of fluorine which had been made up to the year 1923 are summarised in Kayser’s ‘Handbuch der Spektroscopie’ (vol. 5, p. 444; vol. 7, p. 401). They include measurements of lines attributed to fluorine by various workers, but there is no attempt to classify the lines of the neutral atom, the singly ionised atom, etc. Gale and Monk, however, have since published further measures of fluorine lines, and have made the beginnings of a classification by distinguishing the lines produced in vacuum-tube discharges through fluorine gas from those obtained only from a spark discharge in the gas at atmospheric pressure: Their work has been followed up by Carragan, who has made a study of the Zeeman effects for some of the lines of the former group, and, from the rules of Landé, has deduced the existence of multiplets of the first order and suggested certain term combinations. The results here recorded are the first-fruits of an investigation of the fluorine spectrum under different conditions of excitation. Evidence of at least three successive spectra has been obtained as the exciting agency is gradually intensified. Under the gentlest stimulus the lines which appear form an isolated group in the red and infra-red region of the spectrum. They are in the main identical with the vacuum-tube lines of Gale and Monk, and have been produced simultaneously with strong bands of silicon tetrafluoride when a discharge has been passed through this gas. They have accordingly been assigned to the neutral atom of fluorine. The identification, measurement and classification of these lines form the substance of the present paper. Data concerning the spectra produced by more intense discharges will be published in due course.

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The spectrum of ionised fluorine (F II)

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1930.0135 ◽

1930 ◽

Vol 128 (808) ◽

pp. 600-624 ◽

Cited By ~ 6

Keyword(s):

Neutral Atom ◽

Great Majority ◽

First Record ◽

Potassium Fluoride ◽

Spark Discharge ◽

Resolving Power ◽

Considerable Degree ◽

Silicon Tetrafluoride ◽

Vacuum Tube ◽

Vacuum Tubes

The first considerable list of lines due to singly-ionised fluorine (72 in number, extending from λ 4934 to λ 3145) was given in 1912 by Porlezza,* who obtained the spectrum by passing discharges through vacuum tubes containing silicon tetrafluoride. At that time it was not possible to assign the lines to the ionised atom, and Porlezza made no attempt to analyse the spectrum. About the same time, Exner and Haschek recorded a list of lines, obtained from a spark between electrodes of carbon impregnated with potassium fluoride, which they attributed to fluorine. The list included a few of Porlezza’s lines and a considerable number of others whose identity remains obscure. Excluding a few minor investigations, recorded in Kayser’s “Handbuch der Spectroscopie,” vol. 7, pp. 401-404, the next contribution of note towards our knowledge of this spectrum was made by Gale and Monk, who obtained 24 of the lines given by Porlezza, as well as 6 others, from a spark discharge in fluorine gas. Although Gale and Monk did not attribute these lines to the ionised atom, they distinguished them from lines produced in vacuum tube discharges in fluorine which have since been shown to belong to the neutral atom. The first record of a spectrum definitely assigned to F + was made by de Bruin,§ about half of whose list of 71 lines between λ 4447 and λ 3057 were included in Porlezza’s list. De Bruin discussed the possibility of analysis of the spectrum, but his data, as it now appears, were insufficient to permit of any satisfactory results. Up to now, therefore, the spectrum has been very imperfectly known, and the present investigation (which forms part of a general research on the successive spectra of fluorine, of which some of the results have already been published||) was undertaken in the hope of obtaining more definite knowledge. 469 lines have been obtained, of which nearly 200 have been classified. The most prominent lines are those given by Porlezza, Gale and Monk, and de Bruin, and de Bruin’s assignment of the spectrum to the singly ionised atom has been confirmed. The large addition to the lists of those authors is due partly to the inclusion of fainter lines and the extension of the spectrum beyond the limits of their work, but also in a considerable degree to the use of high resolving power, by which several lines previously recorded as single have been found to be multiple. For example, λ 4103 has been resolved into five components, λλ 4447, 4207 into three each, and the “triplets” at λ 3500 and λ 3900 into nine and five, respectively. It should be mentioned also that some of Porlezza’s and de Bruin’s lines have not been confirmed. While some of the fainter lines now recorded might well be due to undetected impurities, there is no doubt that the great majority belong to F II.

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Comparison of Nonlinear Spatial Correlation Models by the Influence of the Data Augmentation to the Classification Risk

Nonlinear Analysis Modelling and Control ◽

10.15388/na.2002.7.1.15200 ◽

2002 ◽

Vol 7 (1) ◽

pp. 31-42

Author(s):

J. Šaltytė ◽

K. Dučinskas

Keyword(s):

Spatial Correlation ◽

Random Fields ◽

Data Augmentation ◽

Gaussian Random Fields ◽

Classification Rule ◽

Numerical Comparison ◽

First Order ◽

Bayesian Risk ◽

Correlation Models

The Bayesian classification rule used for the classification of the observations of the (second-order) stationary Gaussian random fields with different means and common factorised covariance matrices is investigated. The influence of the observed data augmentation to the Bayesian risk is examined for three different nonlinear widely applicable spatial correlation models. The explicit expression of the Bayesian risk for the classification of augmented data is derived. Numerical comparison of these models by the variability of Bayesian risk in case of the first-order neighbourhood scheme is performed.

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Alpha-trimmed first order statistics for the classification of liver US images

2017 6th International Conference on Computer Applications In Electrical Engineering-Recent Advances (CERA) ◽

10.1109/cera.2017.8343358 ◽

2017 ◽

Author(s):

Nishant Jain ◽

Vinod Kumar

Keyword(s):

Order Statistics ◽

First Order

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The Influence of Copper and Silver Nanocolloids on the Quality of Pressed Spring Rapeseed Oil

Agronomy ◽

10.3390/agronomy9100643 ◽

2019 ◽

Vol 9 (10) ◽

pp. 643 ◽

Cited By ~ 2

Author(s):

Kachel ◽

Matwijczuk ◽

Sujak ◽

Czernel ◽

Niemczynowicz ◽

...

Keyword(s):

Silver Ions ◽

Acid Number ◽

Carotenoid Pigments ◽

Foliar Fertilizer ◽

Seed Processing ◽

Infra Red ◽

Infrared Spectral ◽

Silver Nanocolloid

The aim of this study was to evaluate the quality of virgin oil pressed from spring rape seeds cultivated with the use of colloidal nanosilver and nanocopper solutions for processing seeds and as foliar fertilizer. The results show that the use of nanometals for seed processing and foliar fertilization increased the content of carotenoid pigments in the oil. The pigment concentration was higher compared to oil pressed from control seeds. The application of nanocolloids onto the seeds and subsequently on the growing plants contributed to the increase of the oxidative stability of oils. Both the acid number (AN) and peroxide number (PN) values were higher in the studied oils as compared to the control, but did not exceed the required allowable levels. Increased content of silver ions and slightly increased copper content was observed in the pressed oil. An infrared spectral analysis (Fourier-Transformed Infra-Red) conducted in combination with chemometrics allowed the classification of the studied oils in terms of their chemical composition. The analysis revealed the presence of bands characteristic of Cu-O-H vibrations after soaking the seeds and spraying the plants with copper nanocolloid, and of C-O-Ag after fertilization with silver nanocolloid.

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Classification of crop flours based on protein contents using near infra-red spectroscopy and principle component analysis

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/355/1/012002 ◽

2019 ◽

Vol 355 ◽

pp. 012002

Author(s):

I Yuliyanda ◽

R E Masithoh ◽

N Khuriyati ◽

A D Saputro

Keyword(s):

Principle Component Analysis ◽

Component Analysis ◽

Principle Component ◽

Infra Red

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Study on the parameters of spark discharge plasma in a gas mixture of atmospheric pressure under metal treatment

2015 IEEE International Conference on Plasma Sciences (ICOPS) ◽

10.1109/plasma.2015.7179613 ◽

2015 ◽

Author(s):

Mikhail V. Zhuravlev ◽

Gennady E. Remnev ◽

Boris G. Shubin

Keyword(s):

Atmospheric Pressure ◽

Discharge Plasma ◽

Spark Discharge ◽

Gas Mixture ◽

Metal Treatment ◽

Spark Discharge Plasma

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The spectrum of doubly ionised fluorine (F III)

Proceedings of the Royal Society of London. Series A, Containing Papers of a Mathematical and Physical Character ◽

10.1098/rspa.1929.0011 ◽

1929 ◽

Vol 122 (789) ◽

pp. 144-161 ◽

Cited By ~ 5

Keyword(s):

Neutral Atom ◽

Silicon Tetrafluoride ◽

Compact Groups ◽

Great Care ◽

Clear Separation ◽

The Third ◽

Partial Analysis ◽

Sodium Magnesium ◽

Empty Tube ◽

Boron Carbon

When discharges of gradually increasing intensity are passed through a vacuum tube containing silicon tetrafluoride (SiF 4 ), the lines attributable to fluorine appear successively in four fairly compact groups. Between the first three of these groups it is possible, by careful control of the conditions of discharge, to make a clear separation: the fourth, though distinguishable from the third, is less easily isolated. The first group has already been identified as the spectrum of the neutral atom of fluorine (F I). It is probable, therefore, that the others are assignable to F II, F III, and F IV, respectively. The present paper contains an account of the third group, with a partial analysis. The resemblance between the spectrum and that of singly ionised oxygen (O + ), which has the same electron structure as doubly ionised fluorine, confirms its assignment to F ++ . Experimental Arrangements The lines of the spectrum in question appear when strongly condensed discharges are passed through silicon tetrafluoride at very low pressure. The intensity of discharge necessary is indicated by the fact that the lines do not appear in the photographs which accompany Prof. Fowler’s study of the silicon spectra, although Si III and Si IV are shown there in considerable strength. The method of preparation and purification of the gas has been described in the first paper on the spectrum F I ( loc. cit. ). With the stronger discharges, however, the lines of impurities arising from the material of the tube and electrodes were considerably increased in number, and great care was necessary to identify them as completely as possible. Boron, carbon, oxygen, sodium, magnesium and aluminium were the chief impurities found; in particular, the B III pair at λλ 2068, 2066 occurred in surprising strength, and formed the most intense lines in the spectrum. A few lines which have not been identified have been removed from the list of F III lines on account of their appearance in the spectrum, kindly lent by Prof. Fowler, of an "empty” tube containing the minimum amount of air necessary to permit the discharge to pass. The lines of silicon were identified by means of Fowler’s tables.

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