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Nuclear spectroscopic

On-line isothermal chromatography is ideally suited to rapidly and continuously separate short-lived radionuclides in the form of volatile species from less volatile ones. Since volatile species rapidly emerge at the exit of the column, they can be condensed and assayed with nuclear spectroscopic methods. Less volatile species are retained much longer and the radionuclides eventually decay inside the column. [Pg.138]

Rapid SISAK solvent extraction procedures have so far been developed for 20 elements. The SISAK technique has mainly been used for nuclear spectroscopic studies of short-lived fission products in the regions with deformed nuclei around A 110 and A 150 and to characterize previously unknown nuclei, e.g., Pd and Attempts have also been made to use... [Pg.2413]

The Nadonal Aeronaudcs and Space Adminis-tradon has developed NuStar (Nuclear Spectroscopic Telescope Array), a set of two space telescopes carrying a new type of glass lens made from 133 glass layers. NuStar is about one thousand times as sensitive as space telescopes such as Hubble. [Pg.920]

Since the discovery of the Mossbauer effect by Rudolf MSssbauer [1]-[3] in 1958 this nuclear spectroscopic method has found a wide variety of applications in materials science, solid state physics. chemistry, metallurgy, and earth sciences. [Pg.561]

Nuclear spectroscopic studies in polymer/additive research comprise nuclear magnetic resonance (NMR), nuclear quadropole resonance (NQR), electron spin resonance (ESR) and Mossbauer (absorp-tion/emission) spectroscopy (MAS, MES). When everything else has failed in elucidating difficult problems a safe, almost universally valid advice is to try magnetic resonance techniques, NMR and ESR, in this order. [Pg.94]

Information concerning the coordination geometry and dynamics of metal-binding sites in proteins can be obtained from perturbed angular correlation of y-rays (PAC) spectroscopy. The underlying theory of this nuclear spectroscopic method is described in detail in [78] and with special emphasis on biological applications in [79,80]. PAC provides means to determine the nuclear quadrupole interaction at the site of an appropriate nucleus used as a spectroscopic probe. The nuclear quadrupole interactiOTi (NQI) describes the interaction between the electric quadrupole moment... [Pg.352]

The quantum numbers tliat are appropriate to describe tire vibrational levels of a quasilinear complex such as Ar-HCl are tluis tire monomer vibrational quantum number v, an intennolecular stretching quantum number n and two quantum numbers j and K to describe tire hindered rotational motion. For more rigid complexes, it becomes appropriate to replace j and K witli nonnal-mode vibrational quantum numbers, tliough tliere is an awkw ard intennediate regime in which neitlier description is satisfactory see [3] for a discussion of tire transition between tire two cases. In addition, tliere is always a quantum number J for tire total angular momentum (excluding nuclear spin). The total parity (symmetry under space-fixed inversion of all coordinates) is also a conserved quantity tliat is spectroscopically important. [Pg.2445]

Of spectroscopic teclmiques, nuclear magnetic resonance (NMR) has been most widely used to measure orientational ordering in liquid crystals [M, 57 and ]. Most commonly, changes of line splittings in the spectra of... [Pg.2554]

While the presence of sign changes in the adiabatic eigenstates at a conical intersection was well known in the early Jahn-Teller literature, much of the discussion centered on solutions of the coupled equations arising from non-adiabatic coupling between the two or mom nuclear components of the wave function in a spectroscopic context. Mead and Truhlar [10] were the first to... [Pg.11]

Specinfo, from Chemical Concepts, is a factual database information system for spectroscopic data with more than 660000 digital spectra of 150000 associated structures [24], The database covers nuclear magnetic resonance spectra ( H-, C-, N-, O-, F-, P-NMR), infrared spectra (IR), and mass spectra (MS). In addition, experimental conditions (instrument, solvent, temperature), coupling constants, relaxation time, and bibliographic data are included. The data is cross-linked to CAS Registry, Beilstein, and NUMERIGUIDE. [Pg.258]

Europium has been identified spectroscopically in the sun and certain stars. Seventeen isotopes are now recognized. Europium isotopes are good neutron absorbers and are being studied for use in nuclear control applications. [Pg.177]

Physical Chemical Characterization. Thiamine, its derivatives, and its degradation products have been fully characterized by spectroscopic methods (9,10). The ultraviolet spectmm of thiamine shows pH-dependent maxima (11). H, and nuclear magnetic resonance spectra show protonation occurs at the 1-nitrogen, and not the 4-amino position (12—14). The H spectmm in D2O shows no resonance for the thiazole 2-hydrogen, as this is acidic and readily exchanged via formation of the thiazole yUd (13) an important intermediate in the biochemical functions of thiamine. Recent work has revised the piC values for the two ionization reactions to 4.8 and 18 respectively (9,10,15). The mass spectmm of thiamine hydrochloride shows no molecular ion under standard electron impact ionization conditions, but fast atom bombardment and chemical ionization allow observation of both an intense peak for the patent cation and its major fragmentation ion, the pyrimidinylmethyl cation (16). [Pg.85]

Other spectroscopic methods such as infrared (ir), and nuclear magnetic resonance (nmr), circular dichroism (cd), and mass spectrometry (ms) are invaluable tools for identification and stmcture elucidation. Nmr spectroscopy allows for geometric assignment of the carbon—carbon double bonds, as well as relative stereochemistry of ring substituents. These spectroscopic methods coupled with traditional chemical derivatization techniques provide the framework by which new carotenoids are identified and characterized (16,17). [Pg.97]

Cyanuric acid is a titrable weak acid (pffai — 6.88, pifa2 — H-40, pffas — 13.5) (10). The pH of a saturated aqueous solution of pure CA at room temperature is - 4.8. Thermodynamic properties of CA are given ia Table 1. Spectroscopic data are available (1 3). Proton nmr is of limited usefulness because of proton exchange and CA s symmetry and low solubiUty. Nuclear quadmpole resonance measurements ( " N) have been reported (12). [Pg.417]

S. 11.2.2 Nuclear Magnetic Resonance Spectroscopic Studies S. 11.2.3 Infrared Spectroscopic Studies... [Pg.299]

The spectroscopic techniques that have been most frequently used to investigate biomolecular dynamics are those that are commonly available in laboratories, such as nuclear magnetic resonance (NMR), fluorescence, and Mossbauer spectroscopy. In a later chapter the use of NMR, a powerful probe of local motions in macromolecules, is described. Here we examine scattering of X-ray and neutron radiation. Neutrons and X-rays share the property of being found in expensive sources not commonly available in the laboratory. Neutrons are produced by a nuclear reactor or spallation source. X-ray experiments are routinely performed using intense synclirotron radiation, although in favorable cases laboratory sources may also be used. [Pg.238]

The presence of iminium salts can be detected by chemical means or by spectroscopic methods. The chemical means of detecting iminium salts are reactions with nucleophiles and are the subject of this review. The spectroscopic methods are more useful for rapid identification because with the large number of model compounds available now the spectroscopic methods are fast and reliable. The two methods that are used primarily are infrared and nuclear magnetic resonance spectroscopy. Some attempts have been made to determine the presence of iminium salts by ultraviolet spectroscopy, but these are not definitive as yet (14,25). [Pg.176]

The equilibrium geometries produced by electronic structure theory correspond to the spectroscopic geometry R, which assumes that there is no nuclear motion. Contrast this to the Rg geometry, defined via the vibrationally-averaged nuclear positions. [Pg.61]

Normal mode analysis provides a good example of information which is obtainable only through a theoretical calculation, since spectroscopic data does not directly indicate the specific type of nuclear motion producing each peak. Note that it is also possible to animate vibrational modes in some graphics packages. [Pg.66]


See other pages where Nuclear spectroscopic is mentioned: [Pg.376]    [Pg.342]    [Pg.358]    [Pg.56]    [Pg.156]    [Pg.78]    [Pg.376]    [Pg.342]    [Pg.358]    [Pg.56]    [Pg.156]    [Pg.78]    [Pg.1326]    [Pg.1547]    [Pg.1623]    [Pg.2497]    [Pg.222]    [Pg.568]    [Pg.379]    [Pg.332]    [Pg.138]    [Pg.509]    [Pg.302]    [Pg.340]    [Pg.437]    [Pg.394]    [Pg.391]    [Pg.301]    [Pg.461]    [Pg.348]    [Pg.10]    [Pg.2]    [Pg.163]    [Pg.153]   
See also in sourсe #XX -- [ Pg.291 ]




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