Reinigung von Gew�ssern durch h�here Pflanzen

Seidel, Käthe

doi:10.1007/bf00712211

Cited by 85 publications

(22 citation statements)

References 21 publications

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“…Besides the allowed transitions (AmI = f l ) of the isotopes 3sCl and 37Cl there are "forbidden" transitions (Am, = & 2 ) above 9 MHz. These transitions are weakly allowed because of the strong quadrupole interactions [14]. They can be quantitatively understood with the interaction parameters derived from the allowed Table 2 shf For the isotope s7Cl they were not observed because of the relatively small abundance of this isotope.…”

Section: Endor Spectramentioning

confidence: 92%

ENDOR Study of Atomic Hydrogen on Cation Sites in KCl Doped with Sr⁺⁺

Studzinski

Niklas

Spaeth

1980

Physica Status Solidi (b)

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Atomic hydrogen trapped on cation sites (Ht,,-centres) next to Sr2+ in [ l l O ] in KC1 is investigated by ENDOR and ENDOR-induced ESR. The superhyperfine and quadrupole interactions and their relative signs of three types of inequivalent nearest C1-nuclei are determined. The transition energy for the first excited vibrational hydrogen state is derived from the superhyperfine temperature dependence. A further Ht,,-centre is found with Sr2+ probably on a [200] site. The superhyperfine data are discussed considering the local lattice distortion around the cation vacancy.Atomarer Wasserstoff auf Kationenplatz (Ht,.,-Zentren) neben einem Sr2+-Ion in [110] wird in KCI mit Hilfe von ENDOR und ENDOR-induzierter ESR untersucht. Die Superhyperfein-und Quadrupol-Wechselwirkungen und ihr relatives Vorzeichen werden fur drei nichtaquivalente nachste C1-Nachbarn bestimmt. Die Anregungsenergie fur den ersten angeregten Schwingungszustand des Wasserstoffs wird aus der Temperaturabhingigkeit der ENDOR-Linien abgeleitet. Es wird ein weiteres Ht, ,-Zentrum gefunden, bei welchem ein Sr2+-Ion vermutlich auf einem [200]-Platz sitzt. Die Superhyperfein-Wechselwirkungen werden unter Berucksichtigung der lokalen Gitterverzerrung um die Kationenleerstelle diskutiert.

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Section: Endor Spectramentioning

confidence: 92%

ENDOR Study of Atomic Hydrogen on Cation Sites in KCl Doped with Sr⁺⁺

Studzinski

Niklas

Spaeth

1980

Physica Status Solidi (b)

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“…For a given (or guessed) model of the defect (c) the corresponding spin-Hamiltonian (d) has to be solved (see Refs. [26][27][28][29] for the interaction of the defect electron with each individual neighbour nucleus k. Free parameters of the hyperfine tensors A, and possibly of the quadrupole interaction tensors Qk have to be varied systematically until the calculated values of (d) fit to least squares to the experimental angular dependence (e). If the fit works successfully, the atomic model (c) is verified precisely and from the fitting parameters one obtains detailed information about the wave function of the electron at the site of each neighbour nucleus.27 The problem is, that no computer fitting algorithm is intelligent enough to perform such fits for complicated cases shown later without additional information from the experimenter.…”

Section: Endor Measurement Techniquesmentioning

confidence: 99%

Progress in the analysis of defect structures with endor spectroscopy

Niklas

1983

Radiation Effects

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“…Conversion from number to surface or surface to volume is best carried out graphically, in order to smooth out experimental errors, as described in the section on photosedimentation. Nomograms have been developed to reduce the tedium and possible calculation errors involved in number to weight conversion [72,73] . However, it is not in general likely that the conversion from number to weight will be accurate on the following grounds:…”

Section: Particle Size Distribution Transformation Between Number Sumentioning

confidence: 99%

Particle size, shape and distribution

Allen

1981

Particle Size Measurement

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The size of a spherical homogeneous particle is uniquely defined by its diameter. For a cube the length along one edge is characteristic, and for other regular shapes there are equally appropriate dimensions. With some regular particles, it may be necessary to specify more than one dimension. For example: cone, diameter and height; cuboid, length, width and height.Derived diameters are determined by measuring a size-dependent property of the particle and relating it to a linear dimension. The most widely used of these are the equivalent spherical diameters. Thus, a unit cube has the same volume as a sphere of diameter 1.24 units, hence this is the derived volume diameter.If an irregularly shaped particle is allowed to settle in a liquid, its terminal velocity may be compared with the terminal velocity of a sphere of the same density settling under similar conditions. The size of the particle is then equated to the diameter of the sphere. In the laminar flow region, the particle moves with random orientation, but outside this region it orientates itself to give maximum resistance to motion so that the free-falling diameter for an irregular particle is greater in the intermediate region that in the laminar flow region. The free-falling diameter, in the laminar flow region, becomes the Stokes diameter. Stokes' equation can be used for spherical particles, up to a Reynolds number of 0.2, at which value it will give a diameter under-estimation of about 2%. Above 0.2 corrections have to be applied. Corrections may also be applied for non-spherical particles, so that the derived diameter is independent of settling conditions becoming purely a function of particle size. These diameters are particularly useful for characterizing suspended particles in the atmosphere and other cases where the settling behaviour of suspended solids is being examined.For irregular particles, the assigned size usually depends upon the method of measurement, hence the particle sizing technique should, wherever possible, duplicate the process one wishes to control. Thus, for paint pigments, the projected area is important, while for chemical reactants, the total surface area should be determined. The projected area diameter may be determined by microscopy for each individual particle, but surface area is usually determined for a known weight or volume of powder. The magnitude of this surface area will depend on the method of measurement, permeametry, for example, giving a much lower area than gas adsorption. The former gives the surface T. Allen, Particle Size Measurement © T. Allen 1981

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Reinigung von Gew�ssern durch h�here Pflanzen

Cited by 85 publications

References 21 publications

ENDOR Study of Atomic Hydrogen on Cation Sites in KCl Doped with Sr⁺⁺

ENDOR Study of Atomic Hydrogen on Cation Sites in KCl Doped with Sr⁺⁺

Progress in the analysis of defect structures with endor spectroscopy

Particle size, shape and distribution

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Reinigung von Gew�ssern durch h�here Pflanzen

Cited by 85 publications

References 21 publications

ENDOR Study of Atomic Hydrogen on Cation Sites in KCl Doped with Sr++

ENDOR Study of Atomic Hydrogen on Cation Sites in KCl Doped with Sr++

Progress in the analysis of defect structures with endor spectroscopy

Particle size, shape and distribution

Contact Info

Product

Resources

About

ENDOR Study of Atomic Hydrogen on Cation Sites in KCl Doped with Sr⁺⁺

ENDOR Study of Atomic Hydrogen on Cation Sites in KCl Doped with Sr⁺⁺