Beam-foil spectroscopy of neon in the wavelength range 209–602 Å

1977 ◽  
Vol 55 (15) ◽  
pp. 1310-1315 ◽  
Author(s):  
J. A. Kernahan ◽  
K. E. Donnelly ◽  
E. H. Pinnington
Keyword(s):  
Wavelength Range ◽  
Theoretical Calculations ◽  
Experimental Values ◽  
Beam Foil ◽  
Foil Technique

We have measured radiative mean lives from 24 transitions in Ne II–Ne VI in the wavelength range 209–602 Å using the beam-foil technique. We present the first experimental mean lives for nine levels, and our results are compared where possible with theoretical calculations and with other experimental values.

Beam-Foil Mean Life Measurements of Levels in N I–N V

1974 ◽  
Vol 52 (19) ◽  
pp. 1895-1902 ◽  
Author(s):  
J. A. Kernahan ◽  
A. E. Livingston ◽  
E. H. Pinnington
Keyword(s):  
Wavelength Range ◽  
Theoretical Calculations ◽  
Closed Shell ◽  
Oscillator Strengths ◽  
Electron Theory ◽  
Beam Foil ◽  
Experimental Absorption ◽  
Foil Technique

Using the beam-foil technique, we have measured radiative mean lives for 41 levels in N I–N V within the wavelength range 374 to 2064 Å. In some cases we deduce experimental absorption oscillator strengths for comparison with recent theoretical calculations of Nicolaides, who used the 'Non-closed shell many electron theory' of Öksüz and Sinanoğlu. The agreement for lines of higher stages of ionization is very good.

Beam-foil lifetime measurements for some 2p3nl terms of singly-ionized fluorine

1979 ◽  
Vol 57 (7) ◽  
pp. 1046-1050 ◽  
Author(s):  
Eric H. Pinnington ◽  
Robert N. Gosselin ◽  
David J. G. Irwin ◽  
James A. O'Neill
Keyword(s):  
Wavelength Region ◽  
Lifetime Measurements ◽  
Experimental Values ◽  
Beam Foil ◽  
Foil Technique ◽  
Good Agreement

We have used the beam-foil technique in the wavelength region between 3500 and 4500 Å to measure the lifetimes of 10 terms in F II having the configuration 2p3nl, and also to demonstrate the usefulness of the ANDC method for overcoming the effects of cascade repopulation in these measurements. Our results are in good agreement with theory and with other experimental values.

Mean-life measurements for some fluorine transitions in the quartz region

1978 ◽  
Vol 56 (5) ◽  
pp. 517-521 ◽  
Author(s):  
E. H. Pinnington ◽  
D. J. G. Irwin ◽  
A. E. Livingston ◽  
J. A. Kernahan ◽  
R. N. Gosselin ◽  
...  
Keyword(s):  
Data Analysis ◽  
Wavelength Range ◽  
Decay Curve ◽  
The Mean ◽  
Beam Foil ◽  
Foil Technique

The beam-foil technique has been applied to the measurement of the mean lives of seven terms in F III and three terms in F IV, giving rise to transitions in the wavelength range 2150 to 3200 Å. The results are compared with other experimental and theoretical values. Forecasts are made for f-values of some F IV transitions below 500 Å in the 2s2p3–2s22p3p array. Examples of the application of the arbitrarily normalized decay curve (ANDC) method for including the effects of cascade repopulation in the data analysis are discussed.

Infrared spectra, rotational correlation functions, and intermolecular mean squared torques in compressed gaseous methane

1968 ◽  
Vol 46 (11) ◽  
pp. 1331-1340 ◽  
Author(s):  
R. L. Armstrong ◽  
S. M. Blumenfeld ◽  
C. G. Gray
Keyword(s):  
Correlation Functions ◽  
Theoretical Calculations ◽  
Dominant Contribution ◽  
Dispersion Interactions ◽  
Fundamental Vibration ◽  
Order Of Magnitude ◽  
The Mean ◽  
Vibration Rotation ◽  
Experimental Values ◽  
Rotational Correlation

Extensive measurements of the methane ν3 and ν4 fundamental vibration–rotation bands in CH4–He mixtures and the ν3 band in CH4–He, CH4–N2, and CD4–He mixtures have been carried out in infrared absorption at 295 °K to pressures of 3000 atm. Some profiles of the ν3 band in CH4–Ar mixtures and in pure CH4 have also been obtained. Rotational correlation functions, band moments, and intermolecular mean squared torques have been determined from the ν3 band profiles. Theoretical calculations of the mean squared torque due to anisotropic multipolar, induction and dispersion interactions have been carried out. The theoretical and experimental torques are in order-of-magnitude agreement for the CH4–N2 and CH4–CH4 systems; for CH4–He, CD4–He, and CH4–Ar the theoretical values are two to three orders of magnitude too small to account for the experimental values, indicating that in these cases the dominant contribution to the torques is given by the anisotropic overlap forces.

Fluorine mean-life measurements below 1000 Å using the beam–foil technique

1976 ◽  
Vol 54 (10) ◽  
pp. 1014-1021 ◽  
Author(s):  
E. H. Pinnington ◽  
D. J. G. Irwin ◽  
A. E. Livingston ◽  
J. A. Kernahan
Keyword(s):  
Satellite Data ◽  
Wavelength Region ◽  
Wave Functions ◽  
Interstellar Clouds ◽  
Beam Foil ◽  
Foil Technique ◽  
Good Agreement

We have used the beam–foil technique to measure mean lives for 16 transitions in F I–F IV in the wavelength region 400 Å–1000 Å. Good agreement is found with the results of recent calculations, particularly those employing correlated wave functions. The f-value trends for 5 isoelectronic sequences are presented in detail (2p5 2P0–2p43s2 D and 2p5 2P0–2p43s 2P in F I; 2p4 3P–2p33s 3D0 in F II; 2p3 2D0–2s2p4 2D and 2p3 4S0–2s2p4 4P in F III). Our f value for the 955 Å multiplet in F I is also used in conjunction with some new satellite data to show that the fluorine abundance is apparently depleted in interstellar clouds by a factor of at least 3 below its solar value.

scholarly journals Study of the Electric Quadrupole Moments for some Scandium Isotopes Using Shell Model Calculations with Different Interactions

2018 ◽  
Vol 15 (3) ◽  
pp. 304-309
Author(s):  
Baghdad Science Journal
Keyword(s):  
Shell Model ◽  
Theoretical Calculations ◽  
Microscopic Theory ◽  
Model Space ◽  
Electric Quadrupole ◽  
Quadrupole Moments ◽  
Core Polarization ◽  
Model Calculations ◽  
Major Shell ◽  
Experimental Values

The electric quadrupole moments for some scandium isotopes (41, 43, 44, 45, 46, 47Sc) have been calculated using the shell model in the proton-neutron formalism. Excitations out of major shell model space were taken into account through a microscopic theory which is called core polarization effectives. The set of effective charges adopted in the theoretical calculations emerging about the core polarization effect. NushellX@MSU code was used to calculate one body density matrix (OBDM). The simple harmonic oscillator potential has been used to generate the single particle matrix elements. Our theoretical calculations for the quadrupole moments used the two types of effective interactions to obtain the best interaction compared with the experimental data. The theoretical results of the quadrupole moments for some scandium isotopes performed with FPD6 interaction and Bohr-Mottelson effective charge agree with experimental values.

Crystal structure, thermodynamic properties and detonation characterization of bis(5-amino-1,2,4-triazol-3-yl)methane

2020 ◽  
Vol 76 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Hongya Li ◽  
Biao Yan ◽  
Haixia Ma ◽  
Zhiyong Sun ◽  
Yajun Ma ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Detonation Velocity ◽  
Theoretical Calculations ◽  
Detonation Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Equivalent Equation ◽  
Experimental Values ◽  
Experimental Density

Bis(5-amino-1,2,4-triazol-3-yl)methane (BATZM, C5H8N8) was synthesized and its crystal structure characterized by single-crystal X-ray diffraction; it belongs to the space group Fdd2 (orthorhombic) with Z = 8. The structure of BATZM can be described as a V-shaped molecule with reasonable chemical geometry and no disorder. The specific molar heat capacity (Cp,m ) of BATZM was determined using the continuous Cp mode of a microcalorimeter and theoretical calculations, and the Cp,m value is 211.19 J K−1 mol−1 at 298.15 K. The relative deviations between the theoretical and experimental values of Cp,m , HT – H 298.15K and ST – S 298.15K of BATZM are almost equivalent at each temperature. The detonation velocity (D) and detonation pressure (P) of BATZM were estimated using the nitrogen equivalent equation according to the experimental density; BATZM has a higher detonation velocity (7954.87 ± 3.29 m s−1) and detonation pressure (25.72 ± 0.03 GPa) than TNT.

TEMPERATURE EFFECT ON THERMOMECHANICAL PROPERTIES OF BERYLLIUM CHALCOGENIDES BeS, BeSe AND BeTe

2006 ◽  
Vol 20 (01) ◽  
pp. 49-61 ◽  
Author(s):  
F. BENKABOU
Keyword(s):  
Elastic Constants ◽  
Dynamic Properties ◽  
Theoretical Calculations ◽  
Thermomechanical Properties ◽  
Structural Dynamic ◽  
Experimental Values ◽  
Beryllium Chalcogenides ◽  
Increasing Temperature ◽  
And Diffusion ◽  
Good Agreement

We have used the molecular-dynamic method for the calculation of the structural, dynamic and elastic properties of group BeS , BeSe and BeTe compounds for temperature ranging from 300 to 1200 K. Tersoff potential has been used to model the interaction between the groups II–VI compound atoms. The structural properties of cubic BeS , BeSe and BeTe have been calculated, and good agreement between the calculated and experimental values have been found. We have also predicted the elastic constants and diffusion coefficients of BeS , BeSe and BeTe . The values found compare very well with the theoretical results. For the temperature range under study, all elastic constants and dynamic properties show a softening with increasing temperature very similar to the theoretical calculations.

scholarly journals Synthesis, characterization and theoretical calculations of Cu(I) complex of trithiocyanuric acid [Cu(ttc)3]

2018 ◽  
Vol 23 (2) ◽  
pp. 241-266 ◽  
Author(s):  
Ximena Verónica Jaramillo-Fierro ◽  
César Zambrano ◽  
Francisco Fernández ◽  
Regino Saenz-Puche ◽  
César Costa ◽  
...  
Keyword(s):  
Computational Study ◽  
Theoretical Calculations ◽  
Photophysical Properties ◽  
Vibrational Frequencies ◽  
Basis Sets ◽  
Vertical Excitation ◽  
Experimental Values ◽  
Homo Lumo ◽  
Perchlorate Hexahydrate ◽  
Good Agreement

A new Cu(I) complex constructed by reaction of trithiocyanuric acid (ttc) and copper (II) perchlorate hexahydrate has been successfully synthesized by a slow sedimentation method in a DMF solvent at room temperature. The molecular structure of the compound was elucidated by MALDI-TOFMS, UV Vis and FTIR spectroscopy, DSC-TGA analysis and magnetic susceptibility measurement. The proposed structure was corroborated by a computational study carried out with the Gaussian09 and AIMAII programs using the RB3LYP hybrid DFT functional with both 6-31G and Alhrich-TZV basis sets. The calculated vibrational frequencies values were compared with experimental FTIR values. Photophysical properties of the synthesized complex were evaluated by UV-Visible spectroscopy and compared with computed vertical excitation obtained from TDDFT. The theoretical vibrational frequencies and the UV Vis spectra are in good agreement with the experimental values. Additionally, the Frontier Molecular Orbitals (HOMO-LUMO) and the Molecular Electrostatic Potential of the complex was calculated using same theoretical approximation. The results showed the interaction between three coordinatedl igand atoms and the Cu(I) ion.

scholarly journals The Solar X-Ray Line Spectrum 5.5 – 12Å

1984 ◽  
Vol 86 ◽  
pp. 136-136
Author(s):  
D.L. McKenzie
Keyword(s):  
Wavelength Range ◽  
Theoretical Calculations ◽  
High Sensitivity ◽  
Line Spectrum ◽  
Low Density ◽  
X Ray ◽  
R Ratio ◽  
G Ratio ◽  
Limiting Value ◽  
Line Strengths

The SOLEX X-ray spectrometers on the USAF P78–1 satellite have measured solar X-ray spectra in the 5.5–12Å range under a variety of flaring and nonflaring conditions. High sensitivity, obtained by summing data from several successive spectral scans, enabled the detection of 80 lines, 17 of which remain unidentified. The stronger lines were observed with individual scans during the course of flare development. This capability, along with the use of nonflare spectra, facilitated the identification of several lines. The lines of Fe XXII - XXIV, present in hot flare plasmas, are prominent in this wavelength range. For many of these lines, theoretical and observed line strengths will be compared. Diagnostically useful line ratios were evaluated for the helium-like species Mg XI, Al XII, and Si XIII. The density-sensitive R ratio was consistent with theoretical calculations of the low-density limiting value for Mg XI and Si XIII, the only species for which it was evaluated. In all cases the G ratio was below calculated values.

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