The Optogalvanic Spectrum of Neutral Lanthanum between 5610 and 6110 Å

We report on a complete optogalvanic spectrum of a discharge burning in a La-Ar gas mixture, in the spectral range 5610–6110 Å (17,851 to 16,364 cm−1). About 1900 overlapping laser scans, each between 1 and 1.5 cm−1 wide, were necessary to cover this range. The resolution of the spectra is limited by the Doppler width of the spectral features to about 0.03 cm−1 (or ca. 0.01 Å) and is comparable with a Fourier-transform spectrum, but the sensitivity is much higher. Indeed, we could find more than 1800 lines, from which about 800 could be classified as transitions between known energy levels. The main focus of the investigations was to discover previously unknown energy levels by means of excitation of unclassified spectral features.

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New Energy Levels of Neutral Lanthanum Derived from an Optogalvanic Spectrum between 5610 and 6110 Å

Atoms ◽

10.3390/atoms8040088 ◽

2020 ◽

Vol 8 (4) ◽

pp. 88

Author(s):

Laurentius Windholz ◽

Tobias Binder

Keyword(s):

Spectral Range ◽

Energy Levels ◽

Laser Induced Fluorescence ◽

Spectral Lines ◽

Gas Mixture ◽

Line List ◽

New Energy ◽

Ar Gas

In a previous paper, we reported on a complete optogalvanic (OG) spectrum of a discharge burning in a La–Ar gas mixture, in the spectral range 5610–6110 Å (17,851 to 16,364 cm−1). Now we are able to communicate further new energy levels, found via searching for laser-induced fluorescence lines when exciting unclassified lines from the OG spectrum. We were able to find 17 new levels, and for two further levels, the line list has extended. With the help of these 19 levels, we could classify 132 spectral lines.

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Characterisation Of Polysacharides And Lipids From Selected Green Algae Species By FTIR-ATR Spectroscopy

Research Papers Faculty of Materials Science and Technology Slovak University of Technology ◽

10.1515/rput-2015-0011 ◽

2015 ◽

Vol 23 (36) ◽

pp. 97-102 ◽

Cited By ~ 2

Author(s):

Alica Bartošová ◽

Lenka Blinová ◽

Kristína Gerulová

Keyword(s):

Fourier Transform ◽

Infrared Spectroscopy ◽

Ftir Spectroscopy ◽

Green Algae ◽

Spectral Range ◽

Chlorella Sorokiniana ◽

Spectral Features ◽

Fourier Transformed Infrared Spectroscopy ◽

Atr Spectroscopy ◽

Chromochloris Zofingiensis

Abstract Fourier transform infrared (FTIR) spectroscopy was used in this study to identify and determine spectral features of Chromochloris zofingiensis (Dönz) Fucíková et L.A. Lewis (SAG 211-14, Gottingen, Germany), Acutodesmus obliguus (Turpin) Hegewald (SAG 276-1, Gottingen, Germany) and Chlorella sorokiniana (K. Brandt) Pröschold et Darienko (SAG 211-40c, Gottingen, Germany). Polysaccharides and lipids from these three algae species were determined using Fourier Transformed Infrared Spectroscopy (FTIR) with ATR accessory with diamante crystal in spectral range from 400 – 4000 cm−1 and resolution 4.

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Improved energy levels and wavelengths of Pr II from a high-resolution Fourier transform spectrum

Journal of Physics B Atomic Molecular and Optical Physics ◽

10.1088/0953-4075/45/9/095001 ◽

2012 ◽

Vol 45 (9) ◽

pp. 095001 ◽

Cited By ~ 9

Author(s):

N Akhtar ◽

L Windholz

Keyword(s):

Fourier Transform ◽

High Resolution ◽

Energy Levels ◽

Fourier Transform Spectrum

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Experimental Investigation of the Hyperfine Structure of Neutral Praseodymium Spectral Lines and Discovery of New Energy Levels

International Journal of Chemistry ◽

10.5539/ijc.v9n1p7 ◽

2016 ◽

Vol 9 (1) ◽

pp. 7 ◽

Cited By ~ 3

Author(s):

Shamim Khan ◽

Imran Siddiqui ◽

Syed Tanweer Iqbal ◽

Zaheer Uddin ◽

G. H. Guthöhrlein ◽

...

Keyword(s):

Fourier Transform ◽

Hyperfine Structure ◽

Laser Excitation ◽

Energy Levels ◽

Spectral Lines ◽

Wave Number ◽

Experimental Investigations ◽

Angular Momenta ◽

New Energy ◽

Fourier Transform Spectrum

Experimental investigations of Pr I spectral lines were performed by means of laser induced fluorescence spectroscopy, using a hollow cathode discharge lamp as source of free atoms. The wavelengths for the laser excitation were found by the help of a highly resolved Fourier transform spectrum. Altogether we excited 236 unclassified lines and analysed their hyperfine structure, which led, together with the measured wavelengths of the observed fluorescence lines, to the discovery of 32 new even parity and 38 odd parity fine structure energy levels. These levels allow to classify more than 670 spectral lines of Pr I. The wave number calibrated Fourier transform spectrum allowed us to determine the energies of most of these newly discovered levels with an uncertainty of 0.015 cm-1. Angular momenta, parity, and magnetic and electric hyperfine interaction constants (A and B) of the new levels were also determined.

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Laser Spectroscopic Investigations of Praseodymium I Transitions: New Energy Levels

Advances in Optical Technologies ◽

10.1155/2012/639126 ◽

2012 ◽

Vol 2012 ◽

pp. 1-34 ◽

Cited By ~ 3

Author(s):

Zaheer Uddin ◽

Driss El Bakkali ◽

B. Gamper ◽

Shamim Khan ◽

Imran Siddiqui ◽

...

Keyword(s):

Fourier Transform ◽

Fluorescence Spectroscopy ◽

Energy Levels ◽

Laser Induced Fluorescence ◽

Wave Number ◽

Spectroscopic Investigations ◽

New Energy ◽

Fourier Transform Spectrum ◽

Laser Spectroscopic

We report the discovery of about 140 new energy levels of the neutral praseodymium atom, found by means of laser-induced fluorescence spectroscopy. Their energy has been determined with an uncertainty of 0.010 cm−1 using a wave number calibrated Fourier-transform spectrum.

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Spatial Spectrum Analyzer (SSA): A tool for calculations of spatial distribution of fast Fourier transform spectrum from Object Oriented Micromagnetic Framework output data

Computer Physics Communications ◽

10.1016/j.cpc.2014.10.027 ◽

2015 ◽

Vol 189 ◽

pp. 207-212 ◽

Cited By ~ 8

Author(s):

Marek Frankowski ◽

Jakub Chęciński ◽

Maciej Czapkiewicz

Keyword(s):

Fourier Transform ◽

Spatial Distribution ◽

Fast Fourier Transform ◽

Object Oriented ◽

Spatial Spectrum ◽

Spectrum Analyzer ◽

Output Data ◽

Fast Fourier Transform Spectrum ◽

Fourier Transform Spectrum

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The Fourier transform spectrum of the coloured vibrations in mono- and dideuteroacetylene

Chemical Physics Letters ◽

10.1016/0009-2614(93)85562-3 ◽

1993 ◽

Vol 206 (1-4) ◽

pp. 343-348 ◽

Cited By ~ 16

Author(s):

A. Pisarchik ◽

M. Abbouti Temsamani ◽

J. Vander Auwera ◽

M. Herman

Keyword(s):

Fourier Transform ◽

The Fourier Transform ◽

Fourier Transform Spectrum

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An automatic means to discriminate between earthquakes and quarry blasts

Bulletin of the Seismological Society of America ◽

10.1785/bssa08006b2143 ◽

1990 ◽

Vol 80 (6B) ◽

pp. 2143-2160

Author(s):

Michael A. H. Hedlin ◽

J. Bernard Minster ◽

John A. Orcutt

Keyword(s):

Fourier Transform ◽

Spectral Features ◽

Single Event ◽

Vertical Array ◽

Signal To Noise ◽

Spectral Character ◽

Frequency Pattern ◽

Time Frequency ◽

Cepstral Analysis ◽

Double Fourier Transform

Abstract In this article we discuss our efforts to use the NORESS array to discriminate between regional earthquakes and ripple-fired quarry blasts (events that involve a number of subexplosions closely grouped in space and time). The method we describe is an extension of the time versus frequency “pattern-based” discriminant proposed by Hedlin et al. (1989b). At the heart of the discriminant is the observation that ripple-fired events tend to give rise to coda dominated by prominent spectral features that are independent of time and periodic in frequency. This spectral character is generally absent from the coda produced by earthquakes and “single-event” explosions. The discriminant originally proposed by Hedlin et al. (1989b) used data collected at 250 sec−1 by single sensors in the 1987 NRDC network in Kazakhstan, U.S.S.R. We have found that despite the relatively low digitization rate provide by the NORESS array (40 sec−1) we have had good success in our efforts to discriminate between earthquakes and quarry blasts by stacking all vertical array channels to improve signal-to-noise ratios. We describe our efforts to automate the method, so that visual pattern recognition is not required, and to make it less susceptible to spurious time-independent spectral features not originating at the source. In essence, we compute a Fourier transform of the time-frequency matrix and examine the power levels representing energy that is periodic in frequency and independent of time. Since a double Fourier transform is involved, our method can be considered as an extension of “cepstral” analysis (Tribolet, 1979). We have found, however, that our approach is superior since it is cognizant of the time independence of the spectral features of interest. We use earthquakes to define what cepstral power is to be expected in the absence of ripple firing and search for events that violate this limit. The assessment of the likelihood that ripple firing occurred at the source is made automatically by the computer and is based on the extent to which the limit is violated.

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