Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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32228 Publications
Identification of Excited States in the 68Se with Cluster Detectors
Skoda, S.; Fiedler, B.; Becker, F.; Eberth, J.; Freund, S.; Steinhardt, T.; Stuch, O.; Thelen, O.; Thomas, H. G.; Käubler, L.; Reif, J.; Schnare, H.; Schwengner, R.; Servene, T.; Winter, G.; Fischer, V.; Jungclaus, A.; Kast, D.; Lieb, K. P.; Teich, C.; Ender, C.; Härtlein, T.; Köck, F.; Schwalm, D.; Baumann, P.;
  • Physical Review C Volume 58 Number 1 July 1998 PRC 58 R5-R9

Publ.-Id: 1261 - Permalink


The Formation of Narrow Nanocluster Bands in Ge-Implanted SiO2-Layers
von Borany, J.; Grötzschel, R.; Heinig, K.-H.; Markwitz, A.; Schmidt, B.; Skorupa, W.; Thees, H.-J.;
The paper describes the formation of Ge nanocrystals in thin thermally grown SiO2 layers (dox=<100 nm) using implantation of 1015 - 2x1016 Ge+/cm2 and subsequent annealing. Although the implanted Ge depth profile is distributed over almost the whole SiO2 layer, a very narrow band (typical width 5 nm) of Ge nanoclusters very close but well-separated to the Si/SiO2-interface is formed by self-organization under specified annealing conditions. A possible mechanism for this self-organization process is discussed including nucleation phenomena, Ostwald ripening and defect-stimulated interface processes. Simple MOS-structures were prepared and the effect of charge storage inside the clusters has been derived from C-V characteristics.
Keywords: Ge nanocrystals, SiO2 films, ion beam synthesis, electron microscopy, non-volatile memory
  • Solid-State Electronics 43 (1999) 1159-1163
  • Lecture (Conference)
    European Materials Research Society Spring Meeting (E-MRS'98); Symposium N, Session V: Nanomaterials; June 16-19, 1998, Strasbourg, France

Publ.-Id: 1260 - Permalink


Computersimulationen zu Struktur und Wachstum von Bornitrid
Albe, K.;
Dünne Filme aus kubischem Bornitrid (c-BN) sind aufgrund ihrer herausragenden thermomechanischen, chemischen und elektronischen Eigenschaften von besonderem Interesse für die Materialforschung. Bornitrid in der kubischen Phase ist das nach Diamant härteste bekannte Material. Anders als Kohlenstoff verhält es sich gegenüber ferrithaltigen Metallen chemisch inert und zeigt auch bei hohen Temperaturen eine vergleichsweise geringere Oxidationsneigung. Wegen seiner hohen thermischen Stabilität und der Möglichkeit, dünne Schichten bei niedrigen Temperaturen zu synthetisieren, ist Bornitrid  als  Hard-Coating-Material für Werkzeuge besonders geeignet. Mögliche Anwendungen für mikroelelektronische Hochleistungsbauelemente ergeben sich aus der hohen Wärmeleitfähigkeit und der weiten Bandlücke (Eg ~ 6 eV). Bornitrid kann mit Beryllium und Silizium n- bzw. p-Typ dotiert werden und läßt sich mit einer Oxidschicht passivieren. Die optische Transparenz im sichtbaren und Infrarotbereich macht das Material zudem für die Oberflächenvergütung optischer Bauelemente geeignet. ...
  • Open Access LogoForschungszentrum Rossendorf; FZR-228 Dissertation TU Dresden; April 1998
  • Invited lecture (Conferences)
    Workshop "Molekulare Dynamik" des SFB 438 der Universität Augsburg, Herrsching, April 24, 1998 (invited lecture)

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Publ.-Id: 1259 - Permalink


Anwendung von Kleinwinkelstreuverfahren zum Nachweis verformungsbedingter Strukturschädigung
Böhmert, J.; Große, M.;
Der Einfluß plastischer Verformung nach einsinniger Zug- und Biegebelastung auf die Kleinwinkelstreuintensität wurde an technischen Al-Legierungen untersucht.
Bei geeigneter Versuchstechnik lassen sich sowohl mit Röntgenstrahlung als auch mit Neutronen verformungsbedingte Effekte nachweisen. Sie sind im Einschnürbereich einer Zugprobe als Porenstreuung und im Bereich vor der Rißspitze von biegeverformtem, hochduktilem Aluminium als Streuung an Versetzungsstrukturen zu interpretieren. Durch punktförmiges Abtasten mit einem stark fokussierten Synchrotron-Röntgenstrahl können inhomogene Schädigungsstrukturen mit hoher Ortsauflösung nachgewiesen werden. Diese mit SM-SAXS (Scanning Microbeam - Small Angle X-ray Scattering) bezeichnete Technik ist ein Schritt zur Entwicklung eines
Kleinwinkelstreu-Mikroskops.

Small Angle Scattering Characterization of deformation-damaged microstructure
The microstructural changes preceding the ductile fracture were investigated by small angle scattering methods at commercial Al alloys. Within the necking region of tensile deformed specimens additional small angle scattering effects can be measured. They are in agreement with the assumption of pore scattering. The inhomogeneous deformation field ahead the crack tip of a bended and precracked specimen can be monitored by scanning with a highly focussed X-ray beam of a Synchrotron source. In this case the scattering intensity decreases with increasing distance from the crack tip. The effect can be interpreted as scattering at the dislocation arrangements. The used scanning microbeam small angle X-ray scattering technique is a first step to the development of a "small angle scattering microscope".
  • Open Access LogoForschungszentrum Rossendorf; FZR-229

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Publ.-Id: 1258 - Permalink


Selective Accumulation of Heavy Metals by three indigenous Bacillus strains, B. cereus, B. megaterium and B. sphaericus, from drain waters of a uranium waste pile
Selenska-Pobell, S.; Panak, P.; Miteva, V.; Boudakov, I.; Nitsche, H.;
  • FEMS Microbiology Ecology 29, p. 59-67 (1999)

Publ.-Id: 1257 - Permalink


Molecular Bacterial Diversity in Soils and Waters of Three East German Uranium Mining Waste Piles
Satschanska, G.; Kampf, G.; Selenska-Pobell, S.;
  • Poster
    Poster auf der ISME-8, Halifax, Kanada, 7.-14.8.1998
  • Poster
    Uranium Mining and Hydrogeology II, Freiberg, Germany, 15.-17.09.1998

Publ.-Id: 1255 - Permalink


Random and Repetitive Primer Amplified Polymorphic DNA Analysis of Bacillus Sphaericus
Miteva, V.; Selenska-Pobell, S.; Mitev, V.;
  • Journal of Applied Microbiology 86, 928-936 (1999)

Publ.-Id: 1254 - Permalink


Erhöhung der Zuverlässigkeit der Bestimmung der Neutronenbelastung von WWER-Reaktorkomponenten zwecks Ableitung von Vorschlägen für eine sicherere Betriebsführung von WWER-Reaktoren
Böhmer, B.; Borodkin, G. I.; Brodkin, E. B.; Gorbunov, V. P.; Manturov, G. N.; Tsiboulia, A. M.; Zaritsky, S. M.;
The results of a project sponsored by the German Bundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie are presented. The Project aimed to improve the safety against embrittlement of VVER-1000 type reactors by a more reliable and accurate determination of the neutron load of reactor pressure vessels. Therefore, six scientist from three Russian research institutions were sponsored to support with their work another BMBF project of the FZR aimed at the same goal. By providing reliable data for the evaluation of ex-vessel neutron activation experiments at two VVER-1000 and formulating the corresponding reactor models a basis has been established for further investigations as well in the FZR as well as in several Russian and Western research institutions. The leading Russian nuclear data library ABBN/MULTIC has been improved and tested. The uncertainties affecting the calculations of the fluence spectrum at the outer boundary of the pressure vessel have been analysed and a spectrum covariance
matrix has been derived. The methodologies for the experimental determination of activation rates and for calculations of fluence spectra and activation rates have been further developed and tested by interlaboratoy comparisons. Measurements of different laboratories were compared with each other, as well as the corresponding calculations. Moreover,
measurements and calculations were compared against each other, partly with participation of further Russian, Czech and Western institutes. The results of the Intercomparisons have been evaluated by the "International Workshop on the Balakovo-3 Interlaboratory Dosimetry Experiment" in September 1997 in Rossendorf. As a result of these works a better evaluation of the reached accuracies was possible and proposals for an improvement of the used methods could be derived.
  • Open Access LogoForschungszentrum Rossendorf; FZR-220, Juli 1998

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Publ.-Id: 1252 - Permalink


Nutzung der statistischen Informationstheorie und eines tensororientierten Klassifizierungsverfahrens zur Signalerkennung an einem chemischen Prozeß
Hoppe, D.;

Die Klassifikation eines chemisch-verfahrenstechnischen Prozesses nach Gefahrenklassen wird unter besonderer Berücksichtigung der Prozeßsicherheit behandelt. Mangels verläßlicher A-priori-Information über den Prozeß (z.B. eines dynamischen Prozeßmodells) werden klassifizierungsrelevante Prozeßeigenschaften (Merkmale) allein aus Prozeßsignalen gewonnen. Fundamentales Hilfsmittel ist dabei die statistische Informationstheorie. Außer durch die Anwendung eines speziellen und - weil zur Kategorie der Assoziativspeicher gehörenden - besonders einfachen Klassifikators wird insbesondere durch die Nutzung der statistischen Informationstheorie erreicht, daß die Klassifizierungsergebnisse im Interesse der Prozeßsicherheit transparent und nachvollziehbar sind; ungeeignete Merkmale können dadurch leicht lokalisiert werden. Wie exemplarisch gezeigt wird, sind Zusammenhänge, die informationstheoretisch zwischen bestimmten Prozeßsignalen nachgewiesen werden, für die Strukturierung eines dynamischen Prozeßmodells nutzbar. Ein solches Modell kann zur Effektivierung der Prozeßmerkmale und folglich zur genaueren Klassifikation genutzt werden.
  • Open Access LogoForschungszentrum Rossendorf; FZR-225

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Publ.-Id: 1251 - Permalink


Crystallization and Surface Erosion of SiC by Ion Irradiation at Elevated Temperatures
Heera, V.; Stoemenos, J.; Kögler, R.; Voelskow, M.; Skorupa, W.;
  • Journal of Applied Physics 85 (1999) 1378
  • Lecture (Conference)
    ECSCRM '98 (2nd European Conf. on Silicon Carbide and Related Materials), Montpellier, Sept. 2 - 4, 1998

Publ.-Id: 1250 - Permalink


Tribological Properties and Hardness of Silicon Nitride Ceramics after Ion Implantation and Subsequent Annealing
Brenscheidt, F.; Matz, W.; Wieser, E.; Möller, W.;
  • Surface & Coatings Technology 110 (1998) 188-193

Publ.-Id: 1249 - Permalink


Identifying Dangerous States in Chemical Plants Using Neural Networks
Hessel, G.; Neumann, J.; Schlüter, S.; Schmitt, W.; Tefera, N.; van der Vorst, K.; Weiß, F.-P.;
This paper describes the application of three-layer perceptron networks to the identification and diagnosis of dangerous states in strongly exothermic semibatch reactions. To assess the potential danger of different faults, separate perceptron networks were used for danger assessment and for fault isolation. Results are presented to illustrate the performance of the neural-network approach on real process data obtained from typical faults of a catalytic esterification process which were simulated in a laboratory reactor.
  • Lecture (Conference)
    Proc. of the 6th European Congress on Intelligent Techniques and Soft Computing EUFIT '98 Aachen, Sept. 7-10, 1998, pp. 1237-1242
  • Contribution to proceedings
    Proc. of the 6th European Congress on Intelligent Techniques and Soft Computing EUFIT '98 Aachen, Sept. 7-10, 1998, pp. 1237-1242

Publ.-Id: 1248 - Permalink


X-Band, Q-Band EPR and EHT-MO Calculations on [ReII(NO)Cl2(OPPh3)3][ReO4]
Voigt, A.; Abram, U.; Böttcher, R.; Strauch, P.; Kirmse, R.;
  • Inorganic Chemistry Communications 1 (1998) 389-391

Publ.-Id: 1247 - Permalink


Bericht der Frühjahrstagung der Studiengruppe für Elektronische Instrumentierung vom 30. März bis 1. April 1998 bei DESY in Hamburg
Gabriel, F.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-226

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Publ.-Id: 1246 - Permalink


Calculation of the Hole Concentration in Boron-Doped Diamond
Fontaine, F.;
  • Journal of Applied Physics, Vol. 85, Number 3, 1 February 1999, pp. 1409-1422

Publ.-Id: 1245 - Permalink


The Canonical Form of the Transition Matrix Elements
Dönau, F.;
  • Physical Review C 58(1998) 872

Publ.-Id: 1244 - Permalink


Untersuchung der Subschwellenerzeugung von Kaonen am COSY-ANKE-Spektrometer - Detektorentwicklung, Modell- und Simulationsrechnungen
Schneider, C.;
  • Other report
    Dissertation bei der Fakultät Mathematik und Naturwissenschaften der Technischen Universität Dresden

Publ.-Id: 1243 - Permalink


Hochfrequenz Elektroneninjektoren für cw-Beschleuniger
vom Stein, P.;
Abstract
For today 's applications of superconducting accelerators like Linear Colliders and Free Electron Lasers (FEL) there is an increasing demand for high brightness beams. So get a high luminosity or high average laser beam power, the accelerator has to operate in cw mode or with a high duty factor. Therefore, new injectors are needed, delivering a low emittance beam with high average currents compatible to the acccelerator's macropulse structure. During the last 14 years the development of rf guns gained more and more importance for normal conducting accelerators. In this field they became the most advanced injector for high brightness beams. Nevertheless, because of the high rf losses they are, like normal conducting accelerators, limited to operation with low duty factors. At Forschungszentrum Rossendorf two concepts were developed to transfer the merits of the rf gun design to injectors with high duty factors. The first project is a thermionic 1.3 GHz rf gun with two decoupled cavities. A combination of rf and dc acceleration allows to operate the copper cavities at low gradients in cw mode. The design parameters of the injector are a low bunch charge of 1 pC with an emittance less than 1 π mm mrad. Because of the high repetiton rate of 1.3 GHz an average current of 400 µA can be reached. A test stand for the injector with a beamline for emittance, energy and bunch length measurement was built up. At average beam currents up to 80µA a normalized transverse emittance of 0.23 π mm mrad was measured. The measured energy width of 8 keV and the bunch length of 8 ps (FWHM) is in a very good agreement with the simulation results. The second project was realized in collaboration with the Budker Institute in Novosibirsk. The goal is the development of a photocathode rf gun with a superconducting cavity operating at high gradients in cw mode. A new design was worked out to solve the related rf and thermal problems. The beam dynamics of a superconducting 3½-cell rf gun were studied in detail by simulation. The resulting ernittance of 5.3 π mm mrad at a bunch charge of 200 pC opens a wide range of applications for high average power FELs. The fabrication of a half cell test cavity was finished in October 1997. First tests are scheduled for the middle of 1998 to prove the feasibility of our design.
  • Open Access LogoForschungszentrum Rossendorf; FZR-227

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Publ.-Id: 1241 - Permalink


Deep Level Traps in the Extended Tail Region of Boron-Implanted n-Type 6H-SiC
Gong, M.; Reddy, C. V.; Beling, C. D.; Fung, S.; Brauer, G.; Wirth, H.; Skorupa, W.;
Deep traps in the boron extended tail region of ion implanted 6HSiC pn junctions formed during annealing have been studied
using deep level transient spectroscopy. Dramatically high concentrations of ~ 1016 cm3 of the D center have been observed
through the unusual appearance of minority peaks in the majority carrier spectra. No evidence is found for any shallow boron
acceptor in this region, but an induced hole trap Ih at EV + 0.46 eV is found under cold implantation conditions. These results
support the picture of the extended tail, rich in boron-vacancy complexes such as the D center, which forms as a result of vacancy
enhanced indiffusion. The dominance of the electrically active D center in the depletion layer of the technologically important SiC
pn junction diode suggests the need for further research in this area. © 1998 American Institute of Physics.
  • Applied Physics Letters, Volume 72, Number 21, pp. 2739-2741

Publ.-Id: 1240 - Permalink


Aluminium-Implantation-Induced Deep Levels in n-Type 6H-SiC
Fung, S.; Gong, M.; Beling, C. D.; Brauer, G.; Wirth, H.; Skorupa, W.;
Deep-level defect centers on the n-side of p + n junction diodes formed by low and elevated temperature aluminum-ion implantation into n-type 6H–SiC have been studied using deep-level transient spectroscopy. Two shallow Al-acceptor levels have been observed in the n region just beyond the implantation depth through their minority-carrier emission signatures. The dominant level is situated at 0.26 eV above the valence band and is accompanied by a shallower level of small intensity. Comparison with photoluminescence results suggests the dominant level (labeled Ak) and the shallower level (labeled Ah), are associated with the cubic and hexagonal lattice sites, respectively. Unlike previously reported results, which show many different implantation-induced donors within the implantation region, only one deep donor level at EC–0.44 eV is found to occur in the postimplantation region, indicating that the various crystal damage sites occur with different spatial distributions.
  • Journal of Applied Physics Volume 84, Number 2, pp. 1152-1154

Publ.-Id: 1239 - Permalink


Dynamic in Situ Diagnostics Using High-Energy Ion Beam Analysis
Möller, W.; Fukarek, W.; Grigull, S.; Kruse, O.; Parascandola, S.;
MeV ion beam analysis (IBA) is presented as a powerful tool for in situ, real-time process diagnostics. With minor additional experimental equipment such as diferential pumping or the installation of special detectors, dynamic stoichiometric profiles can be measured during ion beam or plasma exposure. Spectrum acquisition times of the order of a few minutes or less enable the study of fast and transient diffusion effects and transient surface coverages. Examples are given addressing the diffusion and trapping of hydrogen in nickel around room temperature, the ion beam synthesis of carbon±nitrogen films, the ion beam nitriding of stainless steel, and the diagnostics of the layered structure of cubic boron nitride films. The latter example combines stoichiometric in situ analysis using dynamic ERD and structural in situ analysis using optical ellipsometry.
  • Nuclear Instruments and Methods in Physics Research B 136-138 (1998) 1203-1211

Publ.-Id: 1237 - Permalink


Post Test Calculations of NOKO Experiments within the Framework of a European Research Program
Schaffrath, A.; Dumaz, P.;
In the frame of a European program (EU BWR R&D Cluster), six
test series with an emergency condenser test bundle were
performed in 1996. Within the Physics and Thermalhydraulics
Complementary Action to the BWR Cluster (BWR/CA) the German
Forschungszentrum Rossendorf (FZR) e.V. and the French Com
missariat a l'Energie Atomique (CEA/DRN) have calculated 9
tests and an additional blind test of NOKO bundle experiments
in 1997. These post test calculations were carried out using
the ATHLET computer code (FZR) and the CATHARE2 computer code
(CEA DRN).
The comparison of the experimental and computational results
(e.g. for mass flows, temperatures, capacities, pressure
drops) show an excellent agreement. Despite the good
prediction of global parameters, a variation of local
parameters (e.g. film velocity, void fraction, heat flux) can
be observed. This can be explained by the significant effect
of the tube wall conduction in controlling the heat transfer.
  • Kerntechnik Vol. 63, No. 3, Mai 1998, S. 113-119, ISSN 0932-3902

Publ.-Id: 1236 - Permalink


Automated Production of the PET Tracer 16 alpha-[18F] Fluoroestradiol for Breast Cancer Imaging
Römer, J.; Füchtner, F.; Steinbach, J.; Johannsen, B.;
  • Nucl. Med. Biol. 26 (1999) 473-479

Publ.-Id: 1235 - Permalink


Laserspektroskopische Untersuchungen zur Bestimmung der Speziation von Schwermetallionen in Abwässern von Aufbereitungsprozessen
Geipel, G.; Rutsch, M.; Brendler, V.; Bernhard, G.; Nitsche, H.;
  • Poster
    GDCh Umwelttagung Karlsruhe Sept. 1998

Publ.-Id: 1234 - Permalink


Positronen Emissions Tomographie für die Qualitätskontrolle der Strahlentherapie mit 12C-Ionen.
Enghardt, W.; Haberer, T.; Hasch, B.-G.; Hinz, R.; Jäkel, O.; Krämer, M.; Lauckner, K.; Pawelke, J.; Sobiella, M.;
no abstract
  • Lecture (Conference)
    29. Tagung der Deutschen Gesellschaft für Medizinische Physik, Dresden, 14-17 Okt, 1998
    L. Voigtmann, P. Geyer (Eds.), Tagungsband (1998) 125-126
  • Contribution to proceedings
    29. Tagung der Deutschen Gesellschaft für Medizinische Physik, Dresden, 14-17 Okt, 1998
    L. Voigtmann, P. Geyer (Eds.), Tagungsband (1998) 125-126

Publ.-Id: 1233 - Permalink


Defect Production and Evolution During and After Ion Implantation Studied by a Combination of Time-Ordered BCA and MD Simulations
Posselt, M.;
A novel method is applied to investigate the as-implanted defect structure formed during keV implantation into Si. It uses a combination of time-ordered computer simulations based on the binary collision approximation (BCA) and classical molecular dynamics (MD) simulations.The as-implanted damage created in 30 keV P+, 15 keV As+, and 15 keV B+ implants is analyzed and depth profiles of different defect species are given.
  • Lecture (Conference)
    12th International Conference on Ion Implantation Technology, June 22-26, 1998, Kyoto/Japan

Publ.-Id: 1232 - Permalink


Atomistic Simulation of Ion Implantation into 2D Structures
Schmidt, B.; Posselt, M.; Strecker, N.; Feudel, T.;
  • Computational Materials Science 11 (1998) 87-95

Publ.-Id: 1231 - Permalink


Analysis and Calculation of an Accident with Delayed Scram at NPP Greifswald Using the Coupled Code DYN3D/ATHLET
Kliem, S.;
Analysis and calculation of an abnormal event which occurred in 1989 at the NPP Greifswald (VVER-440/213) are reported about. This event was a scram failure at about 50% nominal power with two of six working main coolant pumps (MCP). The analysis revealed remarkable differences between the active and passive loops due to non-homogeneous coolant mixing in the downcomer and lower plenum in the initial state before the accident. An existing input data deck for the coupled code DYN3D/ATHLET was modified to carry out calculations of this accident. On account of the absence of a mixing model considering loops with forward and loops with backward flow at the same time, the six reactor loops were modeled by a 3-fold (passive), a 2-fold (active) and a single (with the MCP to be switched-off at the beginning of the transient) loop. The comparison of the stationary calculation with the reported data shows a good agreement taking into account the mentioned deviations between the loops. Most of the calculated thermohydraulic parameters during the accident are very close to the measured data. Deviations in the loop temperatures can be explained by the differences in the measured stationary data and by the fact of non-homogeneous coolant mixing in the downcomer and the lower plenum. A small, but continuous power increase was observed during the whole time in the calculation while the measured power was remaining nearly constant. The power behaviour was brought into agreement with the measured data by a correction of the moderator temperature coefficient within the accuracy recommendations of the Atomic Energy Research (AER).
The calculation of this accident is an important contribution to the validation of the coupled code DYN3D/ATHLET. It demonstrated problems of the analysis of real abnormal events on NPP`s.

  • Contribution to proceedings
    1998 International Conference on the Physics of Nuclear Science and Technology, Proceedings pp. 486-491, ANS, La Grange Park, IL (1998)
  • Lecture (Conference)
    1998 International Conference on the Physics of Nuclear Science and Technology

Publ.-Id: 1229 - Permalink


Synthesis and Reactions of New Oxorhenium(V) Complexes with Re-Halogen Bonds. X-Ray Crystal Structure of 3-(Benzyl)azapentane-1.5-dithiolato)iodo-Oxorhenium(V).
Fietz, T.; Leibnitz, P.; Spies, H.; Johannsen, B.;
Treatment of [ReO(SN(R)S)(SMe)] (HSN(R)SH=HS-CH2 CH2-N(R)- CH2 CH2-SH, R=n-propyl 4a, benzyl 4b) with an excess of CH3I at room temperature gave the-SCH3 displaced products [ReO(SN(R)S)I] 5a,b in about 80% yield. [(3-(Benzyl)azapentane-1,5-dithiolato)iodo]oxorheniumV 5b was characterized by single-crystal structure analysis revealing a distorted trigonal bipyramidal geometry with the oxygen and the sulfur atoms forming the equatorial plane. Compounds 5 allow clean transformation to new SNS/thiolato mixed ligand complexes as shown herein by a sample reaction with 1-beta-D-thiogalactose to give 6a.
  • Polyhedron 18 (1999) 1793-1797

Publ.-Id: 1228 - Permalink


Synthesis and Binding Affinities of New 17a-Substituted Estradiol-Rhenium n+1 Mixed-Ligand and Thioether-Carbonyl Complexes
Wüst, F.; Carlson, K. E.; Katzenellenbogen, J. A.; Spies, H.; Johannsen, B.;
  • Steroids 63:665-671, 1998

Publ.-Id: 1227 - Permalink


Combined Effect of Nuclear Coulomb Field and Radial Flow on Two-Pion Correlations
Barz, H.-W.;
  • Contribution to proceedings
    Konferenz CRIS 98 Acicastello Juni 1998

Publ.-Id: 1226 - Permalink


Combined Effects of Nuclear Coulomb Field, Radial Flow and Opaqueness on Two-Pion Correlations
Barz, H.-W.;
  • Physical Review C, Volume 59, Number 4, April 1999

Publ.-Id: 1225 - Permalink


Theoretical Support to the NOKO Experiments
Schaffrath, A.; Prasser, H.-M.;
Several approaches have been undertaken in a number of European countries to study and demonstrate the feasibility of innovative passive safety systems. The European BWR R&D Cluster combines experimental and analytical efforts that are mainly directed to the introduction of passive safety systems into boiling water reactor technology. The main objectives are to use the large scale European test facilities NOKO (Jülich, Germany), PANDA, LINX (Villingen, Switzerland), PANTHERS (Piacenza, Italy) as well as the demonstration power plant Dodewaard (Netherlands) for a synergistic experimental R&D program. The project should additionally contribute to validating and improving thermalhydraulic computer codes. In 1997 a BWR Physics and Thermohydraulic Complementary Action (BWRCA) was established to further assist and broaden the objectives of the EU BWR R&D Cluster. The work presented in this report is performed in the Workpackage Theoretical support to the NOKO experiments and divided into three tasks: Implementation of two phase flow instrumentation, ATHLET calculations of NOKO experiments and approach for the optimization of passive components. FZR is developing two phase flow measurement instrumentation (e.g. conductivity probes), which is installed in parallel to the emergency condenser test bundle. The experimental data are used for the validation of the improved ATHLET condensation model. The evaluation of these experiments shows an undesired accumulation of noncondensable gases in front of the water level and give valuable insights to the phenomena caused by noncondensables. An improved twophase flow instrumentation is suggested based on the collected experience and taking into account the detected problems.

Within the BWRCA FZR had performed 10 post test calculations and an additional blind test calculation of NOKO experiments. The results of these calculations are presented and discussed in detail. These calculations show that ATHLET is able to perform proper calculations. At least goals for an optimization of the emergency condenser are discussed. This is desirable because it allows the decrease of the pressurized BWR surface and the possibility of leakages.
  • Open Access LogoWissenschaftlich-Technische Berichte / Forschungszentrum Rossendorf; FZR-224 Juni 1998

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Publ.-Id: 1224 - Permalink


Anwendungsmöglichkeiten neuartiger EDV-gestützter Erkennungsmethoden zur Identifizierung gefährlicher Betriebszustände in Chemieanlagen (I)
Hessel, G.; Hoppe, D.; Schmitt, W.; Tefera, N.; van der Vorst, K.; Weiß, F.-P.;
Das Vorhaben erbrachte einen Beitrag zur operatorunabhängigen Beurteilung des Prozeß- und Anlagenzustandes chemischer Reaktoren, insbesondere zur Identifizierung gefährlicher Betriebszustände bei der diskontinuierlichen Fahrweise exothermer Reaktionen.
Die Eignung von Mustererkennungsmethoden zur Prozeßdiagnose wurde am Beispiel eines chemischen Laborreaktors für einen stark exothermen Referenzprozeß - säurekatalysierte Veresterung von Essigsäureanhydrid mit Methanol - untersucht. Vor ihrer Anwendung als Zustandsklassifikator mußten die Mustererkennungssysteme zunächst mit den Prozeßdaten des normalen und gestörter Reaktionsverläufe unter Zuhilfenahme von Expertenwissen trainiert werden, um das komplexe nichtlineare Prozeßverhalten bis hin zum Entscheidungsresultat abzubilden. Danach konnte der trainierte Klassifikator zur Prozeßdiagnose genutzt werden.
Die besten Ergebnisse bei der Erkennung von Betriebszuständen in Semibatch-Prozessen wurden mit dreischichtigen Perceptron-Netzen erreicht. Sie konnten auch Mehrfachfehler und nichttrainierte Reaktionsverläufe klassifizieren. Um das Gefährdungspotential von fehlerhaften Betriebszuständen beurteilen zu können, wurden separate Perceptron-Netze für die Gefahren- und Fehlerklassifikation eingesetzt. Ihre Leistungsfähigkeit wurde sowohl für den Semibatch-Betrieb als auch für die kontinuierliche Fahrweise experimentell nachgewiesen.
  • Open Access LogoForschungszentrum Rossendorf; FZR-223 Juni 1998
  • Other report
    Abschlußbericht zum BMBF-Fördervorhaben 01RG94235
  • Other report
    Deutsche Forschungsberichte, UB/TIB Hannover, Elektronische Bibliothek, www.tip.uni-hannover.de, Report 01RG94235 (1998) S. 1-93

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Publ.-Id: 1223 - Permalink


Entwicklung einer fortgeschrittenen Methodik zur Bestimmung der Neutronenbelastung des Druckbehältermaterials vom Reaktor des Typs WWER-1000
Barz, H.-U.; Böhmer, B.; Konheiser, J.; Stephan, I.;
In diesem Projekt wurden für die WWER-1000-Reaktoren Balakovo-3 und Rovno-3 die Parameter der Neutronenbelastung experimentell und theoretisch bestimmt.
Der vorliegende Bericht beschreibt das methodische Vorgehen, welches aus dem reinen Berechnungsteil, der gammaspektrometrischen Analyse der Aktivierungsdetektoren und dem Vergleich der gemessenen und berechneten Werte einschließliche der Spektrumsjustierung besteht. Dieses Instrumentarium, welches allgemein bei der Bestimmung der Neutronenfluenz anwendbar ist, wurde im Projektzeitraum weiter verbessert.
  • Open Access LogoForschungszentrum Rossendorf; FZR-222 Mai 1998

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Publ.-Id: 1222 - Permalink


Magnetic Dipole Bands in 82Rb, 83Rb and 84Rb
Schwengner, R.; Schnare, H.; Frauendorf, S.; Dönau, F.; Käubler, L.; Prade, H.; Grosse, E.; Jungclaus, A.; Lieb, K. P.; Lingk, C.; Skoda, S.; Eberth, J.; de Angelis, G.; Gadea, A.; Farnea, E.; Napoli, D. R.; Ur, C. A.; Bianco, G. L.;
  • Contribution to external collection
    AIP Conf. Proc.(1998), 455, eds. B. M. Sherill, D. J. Movissey and C. N. Davids, 594-597

Publ.-Id: 1221 - Permalink


Nitriding stainless steel at moderate temperature: Time- and depth-resolved characterization of the near surface composition during the nitriding process
Parascandola, S.; Kruse, O.; Richter, E.; Möller, W.;
Time- and depth-resolved compositional analysis has been performed during the nitriding of stainless steel in order to improve the understanding of the nitriding kinetics. It is directly observed that the surface oxide layer acts as a transport barrier. The experimental data are discussed on the basis of a simple transport model that considers the removal of the surface oxide layer due to sputtering, its regeneration from the residual gas and the ballistic implantation depth of nitrogen.
  • Journal of Vacuum Science and Technology B 17(2), Mar/Apr 1999, 855-858
  • Vortrag und Beitrag zu fremden Sammelwerken (Proceedingsband) / Papers from the Fourth International Plasma-Based Ion Implantation Workshop, 2 - 4 June 1998, Dearborn, Michigan, USA, Eds.: J.V. Mantese and C.E. Speck, American Vacuum Society, New...
  • Vortrag (sonstiger): Colorado State University, Dept. of Mechanics and Enegineering, Fort Collins, USA, May 12, 1998

Publ.-Id: 1220 - Permalink


A Low-Mass Drift Chamber System for the HADES-Spectrometer
Dohrmann, F.; Bethge, K.; Enghardt, W.; Fateev, O.; Garabatos, C.; Grosse, E.; Müntz, C.; Karig, W.; Koenig, W.; Smykov, L.; Sobiella, M.; Steigerwald, A.; Stelzer, H.; Stroth, J.; Wüstenfeld, J.; Zanevsky, Y.; Zentek, A.;
A new high resolution (D M/M < 1 %) and high acceptance (45 %) di-electron spectrometer (HADES) has been designed to investigate in-medium properties of hadrons. For tracking of all charged particles (in particular with sufficient resolution for electrons) a system of 24 low-mass drift chambers (Helium based counting gas and Aluminum field and cathode wires), arranged in four tracking planes, is used.
Design aspects of the chambers are reported. Results of performance optimization using various prototype detectors are discussed, including results of an ageing test. Stable operation in the high-multiplicity environment of heavy ion collisions, and a spatial resolution of 70 mm (s) over 80 % of a cell have been demonstrated in two beam experiments.
  • Acta Physica Polonica B No 11, Vol. 29 (1998), 3189-3193

Publ.-Id: 1219 - Permalink


Irradiation Damage Structure in VVER-440 Steels After Irradiation at Different Temperatures and Post-Irradiation Annealing
Große, M.; Böhmert, J.;
Neutron irradiation of the VVER-440-type reactor pressure vessel steel 15Kh2MFA at lower temperature effects an increase of the content of point defects in the iron lattice. The ratio between the magnetic and nuclear scattering of these point defects shows that not only vacancies but also substitution atoms are formed. Additionally small precipitates grow. These precipitates are smaller and have a weaker thermal stability than the precipitates grown in this steel after neutron irradiation at service temperature. In some cases the number of precipitates which can be found in the unirradiated state decreases significantly by irradiation at 60 °C. Annealing at 475 °C/1 h provokes coarsening of the precipitates and re-dissolution of the precipitates formed by irradiation at lower temperature.
  • Contribution to external collection
    ASTM STP 1366, Seattle, June 1998

Publ.-Id: 1218 - Permalink


Experimental Investigation of the Operation Mode of Passive Safety Systems
Fethke, M.; Rossner, L.; Jaegers, H.; Hicken, E. F.; Schaffrath, A.;
The safety concept of the innovative boiling water reactor SWR 1000 is characterised by passive safety systems (e.g. emergency condensers, building condensers, passive initiators). The operation mode and the effectiveness of these safety systems is investigated in the multipurpose thermalhydraulic test facility NOKO at the Forschungszentrum Jülich (FZJ).
The effectiveness of the emergency condenser was determined in more than 200 experiments. Post-test calculations of the emergency condenser experiments were performed with an improved version of the ATHLET code. The comparison of the calculations and the experiments shows a good agreement.
Parallel, the performance of three different designs of the passive initiator was investigated experimentally. The experimental results are used to optimise the design of an additional passive initiator which will be tested in NOKO this year.
Additionally, more than 80 experiments were carried out in NOKO to determine the effectiveness of two different designs of the building condenser. Post-test calculations were performed using the modified computer code RALOC. The comparison of the calculations and the experiments shows a good agreement.

Keywords: SWR1000, NOKO, emergency condenser, ATHLET, building condenser, passive initiator
  • Lecture (Conference)
    ENC '98, Nice, France, 25-29 October 1998
  • Contribution to external collection
    ENC '98, Nice, France, 25-29 October 1998

Publ.-Id: 1217 - Permalink


Dwell-Time Dependence of the Defect Accumulation in Focused Ion Beam Synthesis of CoSi2
Bischoff, L.; Hausmann, S.; Voelskow, M.; Teichert, J.;
Cobalt disilicide microstructures were formed by 70 keV Co2+ focused ion beam implantation into Si(111) at substrate temperatures of about 400°C and a subsequent two step annealing (600°C, 60 min and 1000°C, 30 min in N2). It was found that the CoSi2 layer quality strongly depends on the pixel dwell-time and the implantation temperature. Only for properly chosen parameters countinuous CoSi2 layers could be obtained. Scanning electron microscopy and Rutherford backscatting/channelling investigations were carried out combined with a special preparation technique damage was investigated as a function of dwell-time (1-250 µs) and target temperature (355-415°C). The results show that the irradiation damage increases with the dwell-time.The Si top layer was ammorphization for longer dwell-times although the substrate temperature was always above the critical temperature for amorphization of about 270°C according to the model of Morehead and Crowder. For the high current density of a focused ion beam (1-10 A/cm2) the damage creation reate is higher than the rate of dynamic annealing.
  • Poster
    E-MRS 1998 Spring Meeting, Strasbourg, 16.-19. Juni 1998
  • Nuclear Instruments and Methods in Phys. Res. B 147 (1999) 327-331

Publ.-Id: 1216 - Permalink


Zur Existenz von [ReNCl4-nFn]- (n=1-3) Nitridorhenat(VI)-Gemischtligandenkomplexen - eine EPR-Untersuchung
Voigt, A.; Abram, U.; Kirmse, R.;
  • Zeitschrift für Naturforschung 53b, 1183-1187 (1998)

Publ.-Id: 1215 - Permalink


Ion Beam Synthesis of Gold Nanoclusters in SiO2: Computer Simulations versus Experiments
Strobel, M.; Heinig, K.-H.; Möller, W.; Meldrum, D. S.; Zhou, C. W.; Zuhr, R. A.; White, C. W.;
  • Nuclear Instruments and Methods in Physics Research B 147 (1999) 343-349
  • Lecture (Conference)
    E-MRS Spring Meeting, Strasbourg, France, June 16-19, 1998

Publ.-Id: 1214 - Permalink


(Bu4N)[Re{NB(C6F5)3}CI4(OH2)] - Struktur und EPR-Spektren
Abram, U.; Kohl, F. J.; Öfele, K.; Herrmann, W. A.; Voigt, A.; Kirmse, R.;
  • Zeitschrift für anorganische und allgemeine Chemie 624 (1998) 934-936

Publ.-Id: 1213 - Permalink


Räumliche und zeitliche Korrelation der Solarstrahlung auf unterschiedlich orientierten Flächen in Sachsen
Franke, K.; Rindelhardt, U.;
In der vorliegenden Arbeit wurde die räumliche Verteilung der Einstrahlung für Sachsen anhand von vorwiegend an Solaranlagen gemessenen Einstrahlungswerten untersucht und diskutiert.
Dazu wurde zunächst eine umfangreiche Datenanalyse durchgeführt. Verschiedene Ergebnisse deuten darauf hin, daß an der DWD-Station Chemnitz vermutlich eine Überbewertung der gemessenen Globalstrahlung vorliegt.
Des weiteren wurde gezeigt, daß die an Solaranlagen auf Dächern von Ein- und Zwei-Familienhäusern in den urbanen Gebieten gemessenen Einstrahlungswerte infolge der unvermeidlichen Horizontabschirmung deutlich geringer sind als die auf der Grundlage der DWD-Daten mittels verschiedener Modelle berechnete Einstrahlung auf beliebig orientierte Flächen.
Die räumliche Verteilung der Einstrahlung in urbanen Gebieten Sachsens wurde anhand der im Rahmen des 1000-Dächer-Photovoltaik-Programms an über 20 Standorten in Sachsen gemessenen Einstrahlungswerten bestimmt. Dabei wurde deutlich, daß innerhalb Sachsens an solchen Standorten mit einer mittleren Globalstrahlung (auf die Horizontale) von ca. 900 kWh/m² gerechnet werden kann. Somit können für Neigungen zwischen 25° und 50° sowie Ausrichtungen bis zu 35° mittlere Einstrahlungswerte bis zu 1040 kWh/m² erreicht werden. Nur in günstigen örtlichen Lagen kann auch eine bis zu 15% höhere Einstrahlung erreicht werden.
  • Lecture (Conference)
    11. Internationales Sonnenforum 1998, 26.-30. Juli, Köln
  • Contribution to proceedings
    11. Internationales Sonnenforum 1998, 26.-30. Juli, Köln, Tagungsband S. 881

Publ.-Id: 1212 - Permalink


Netzgekoppelte Photovoltaik-Anlagen - Ergebnisse des 1000-Dächer-Langzeitmeßprogramms in Sachsen
Rindelhardt, U.;
Im Vortrag werden ausgewählte Ergebnisse zum 1000-Dächer-Langzeitmeßprogramm dargestellt. Dies schließt Ergebnisse zur solaren Meteorologie, der Anlagentechnik und der erreichten Erträge und dem Verbraucherverhalten (Privathaushalte) ein.
  • Lecture (Conference)
    2. Merseburger Solartag, 9.6.1998
  • Contribution to external collection
    2. Merseburger Solartag, 9.6.1998

Publ.-Id: 1211 - Permalink


Langzeituntersuchungen an netzgekoppelten Photovoltaikanlagen in Sachsen
Rindelhardt, U.; Teichmann, G.; Futterschneider, H.;
Zwischen 1993 und 1997 wurden 50 kleine netzgekoppelte Photovoltaikanlagen in Sachsen im Rahmen des 1000-Dächer-Photovoltaik-Programms systematisch untersucht. Neben der kontinuierlichen Auswertung der monatlichen Einstrahlung und der Energieerzeugung wurden alle Anlagen mittels eines PV-Anlagen-Analysators vermessen. An 5 Anlagen wurde ein erweitertes Messprogramm durchgeführt.
Die mittlere jährliche Einstrahlung auf geneigte Dachflächen in urbanen Gebieten Sachsens wurde zu 1050 kWh/m² bestimmt. Davon fallen 75 % während der Tageslastspitzen im Sommerhalbjahr an. Die ermittelten Kennlinien der eingesetzten Hauptkomponenten (Module, Wechselrichter) wichen teilweise erheblich von den Datenblattangaben ab. Gut ausgelegte und installierte Anlagen können bei einem Performance Ratio von 80 % einen jährlichen Ertrag von 840 kWh/kWp bringen. Künftig sollten Anlagen im kleinen Leistungsbereich (bis 5 kWp) als Einstranganlagen errichtet werden. Der Energieverbrauch der einbezogenen Haushalte war überraschend hoch. Bei solaren Deckungsgraden von etwa 100 % konnten nur 25 % des erzeugten Stromes direkt in den Haushalten verbraucht werden. Bei Deckungsgraden von kleiner 20 % erreichte der Direktnutzungsgrad etwa 70 %.
  • Open Access LogoForschungszentrum Rossendorf; FZR-221 Mai 1998

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Publ.-Id: 1210 - Permalink


Fragment Mass Distribution of Fission after Incomplete Fusion in the Reaction 7Li(43 AMeV) + 232Th
Ortlepp, H.-G.; Gippner, P.; Herbach, C.-M.; Schilling, K.-D.; Wagner, W.; Penionzhkevich, Y. E.;
  • Nuclear Physics A 642 (1998) 407-418

Publ.-Id: 1209 - Permalink


Oxidation Behaviour of Carbon-Based Materials Used for High-Temperature Gas-Cooled Reactors and Fusion Reactors
Moormann, R.; Alberici, S.; Hinssen, H.-K.; Krüssenberg, A.-K.; Wu, C. H.;
Kinetic formula describing oxidation of several innovative Cbased HTR and fusion reactor materials in oxygen, steam and CO2 are reported for use in computer codes for safety analyses (air/steam ingress accidents). Most data deal with oxidation regime II (in-pore diffusion control) but some information on regime I and III are added, too. The data situation on oxidation of pure graphites and CFCs in O2 and H2O seems to be sufficient but for mixed materials, particularly Si/C composites to be used in fusion reactors, additional experiments are necessary.
  • Lecture (Conference)
    9th CIMTEC (International Conference on Modern Materials & Technologies) 14.-19.06.1998, Florence, Italy
  • Advances in Science and Technology, Vol 24 (1999) 331-8

Publ.-Id: 1208 - Permalink


Proton-Proton Correlations in Central Heavy-Ion Collisions at SIS Energies and the Space-Time Extent of the Emission Source
Kotte, R.; Fopi, C.;
  • Contribution to external collection
    Conf. CRIS 98, Acicastello, June 8-12, 1998, World Scientific Singapore

Publ.-Id: 1207 - Permalink


Radioligands for the Study of the 5-HT Transporter in Vivo
Brust, P.; Scheffel, U.; Szabo, Z.;
Loss of 5-HT transporter (SERT) sites has been implicated in various neurodegenerative diseases and users of some amphetamine derivatives such as MDMA. Therefore, the development of suitable radioligands for neuroimaging of the SERT in the human brain is important. A large number of drugs have been labeled with 11C, 18F or 123I over the last ten years in order to achieve such radioligands. Despite these attempts most of the compounds were found unsuitable because of low target-to-nontarget ratios. Some cocaine-derived radioligands allow SERT imaging of the human brain using positron emission tomography (PET) although they have a limited selectivity. Among the various specific 5-HT uptake inhibitors only [123I]iodonitroquipazine for single photon emission computed tomography (SPECT) and [11C](+)McN5652 for PET appear to meet the criteria of a useful radioligand. There is still a need for the development of new radioligands for SERT imaging. Advances in tracer synthetic methodologies may bring further progress in this field.
  • IDrugs 1999 Vol 2 No 2 , Review Radioligands 129-145

Publ.-Id: 1206 - Permalink


Synthesis, Structure and EPR Spectra of (Bu4N)2-[(OH2)Br4ReNReBr4NReBr4(OH2)]
Abram, U.; Kirmse, R.; Voigt, A.;
  • Inorganic Chemistry Communications 1 (1998) 213-216

Publ.-Id: 1205 - Permalink


Darstellung, Strukturen und EPR-Spektren der Rhenium(II)-Nitrosylkomplexe [Re(NO)Cl2(PPh3)(OPPh3)(OReO3)], [Re(NO)Cl2(OPPh3)2(OReO3)] und [Re(NO)Cl...
Abram, U.; Voigt, A.; Kirmse, R.; Ortner, K.; Hübener, R.; Carballho Rias, R.; Vasquez-Lopez, E.;
  • Z. anorg. Allg. Chem. 624 (1998) 1662-1668

Publ.-Id: 1204 - Permalink


Ein 3D MLE-Algorithmus für die Positronen-Emissions-Tomographie während der Strahlentherapie mit Schwerionen
Lauckner, K.; Enghardt, W.; Hinz, R.; Freyer, R.;
Fuer die Qualitaetssicherung der Praezisionsbestrahlung mit schweren Ionen wurde der Positronen-Emissions-Tomograph BASTEI in die Therapieanlage der GSI Darmstadt integriert.Die Messung der durch Fragmentierung waehrend einer Bestrahlung erzeugten b+-Aktivitaet erlaubt eine Kontrolle der raeumlichen Dosisverteilung nach jeder Therapiefraktion. Als besondere Probleme dieser PET-Anwendung sind die Erfassung von
Annihilationsereignissen in einem eingeschreankten Winkelbereich und eine durch die Dosis limitierte Aktivitaet zu benennen, woraus eine geringe Zaehlstatistik folgt. Unter Beruecksichtigung dieser Messbedingungen wurde der MLE-Rekonstruktionsalgorithmus implementiert. Die Leistungsfaehigkeit des Verfahrens wird anhand von Phantomexperimenten und ersten Patientendaten dargestellt.
SCHLUESSELWOERTER:Positronen-Emissions-Tomographie, Bildrekonstruktion, MLE-Algorithmus, dreidimensional
Keywords: Positronen-Emissions-Tomographie, Bildrekonstruktion, MLE-Algorithmus, dreidimensional
  • Lecture (Conference)
    32. Jahrestagung der Deutschen Gesellschaft für Biomedizinische Technik, 9.-12. September 1998, Technische Universität Dresden
  • Contribution to proceedings
    32. Jahrestagung der Deutschen Gesellschaft für Biomedizinische Technik, 9.- 12. September 1998, Technische Universität Dresden
  • Biomedizinische Technik, Band 43/1, 1998, 28-29

Publ.-Id: 1203 - Permalink


Institute of Nuclear and Hadron Physics; Annual Report 1997
Barz, H.-W.; Dönau, F.; Enghardt, W.; Grosse, E.; Kämpfer, B.; Prade, H.; Schlett, M.; Wünsch, R.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-215 March 1998

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Publ.-Id: 1202 - Permalink


Dose Rate Effects in Focused Ion-Beam Synthesis of Cobalt Disilicide
Hausmann, S.; Bischoff, L.; Teichert, J.; Voelskow, M.; Grambole, D.; Herrmann, F.; Möller, W.;
The influence of the dwell-time in focused ion beam synthesis has been investigated. Cobalt disilicide layers have been produced by 70 keV Co2+ implantation into silicon and have been investigated by Rutherford backscattering spectroscopy and scanning electron microscopy. At an implantation temperature of about 400 °C, it is only possible to form continuous CoSi2 layers using sufficiently short pixel dwell-times. This result is explained by an enhanced damage accumulation for longer dwell-times.
  • Applied Physics Letters, Volume 72, Number 21, 25 May 1998, pp 2719-2721

Publ.-Id: 1201 - Permalink


Implantation of Boron into Hard Metals
Mrochek, I.; Günzel, R.; Matz, W.; Möller, W.; Anishchik, V.;
  • Nukleonika Vol. 44 No. 2 (1999) p. 217-224

Publ.-Id: 1199 - Permalink


Simultankontrolle der Strahlentherapie mit Schwerionen durch Positronen-Emissions-Tomographie.
Hinz, R.; Enghardt, W.; Hasch, B.-G.; Lauckner, K.; Pawelke, J.; Sobiella, M.; Freyer, R.;
Seit Dezember 1997 werden an der experimentellen Therapieeinrichtung der Gesellschaft für Schwerionenforschung Darmstadt Tumorpatienten mit hochenergetischen Kohlenstoffionen behandelt. Diese Strahlen werden beim Eindringen in Gewebe kaum abgelenkt und geben ihre Energie am Ende ihrer Reichweite konzentriert und mit erhöhter biologischer Wirksamkeit ab. Mit einer speziell für diese Anwendung gebauten Positronenkamera werden während der Bestrahlung die Beta+-Zerfälle von Kernen gemessen, die als Nebenprodukt bei Fragmentierungsreaktionen der Ionen des stabilen Therapiestrahles mit den Atomen des Körpergewebes entstehen. Durch Vergleich der gemessenen mit der durch Simulationsrechnungen aus den Daten der Bestrahlungsplanung zu erwartenden Positronenemitterverteilung wird die Genauigkeit der Dosisapplikation jeder einzelnen Therapiefraktion beurteilt.
Keywords: Positronen-Emissions-Tomographie, Strahlentherapie, Schwerionen
  • Lecture (Conference)
    32. Jahrestagung der Deutschen Gesellschaft für Biomedizinische Technik, 09-12 Sep, 1998, Dresden
  • Biomedizinische Technik, Band 43, Ergänzungsband 1 (1998) 30-31

Publ.-Id: 1198 - Permalink


A method for in-vivo treatment plan verification of heavy-ion tumour therapy by positron emission tomography.
Hinz, R.; Byars, L.; Enghardt, W.; Hasch, B.-G.; Lauckner, K.; Pawelke, J.; Sobiella, M.;
A method for controlling the quality of heavy ion tumour therapy by means of positron emission tomography is introduced. It registers the dynamic spatial distribution of beta+-emitters produced by nuclear fragmentation during the fractionated irradiations. It is non-invasive, needs no radioactive isotopes, is performed in-situ at the treatment place and provides a feedback for the therapist. Results of phantom experiments with 12C ion beams will be presented.
  • Lecture (Conference)
    Fifth Int. Conf. on Applications of Physics in Medicine and Biology, Trieste, Italy, 2-6 Sep, 1996
    Physica Medica, Vol. XII, No. 3 (1996) 157
  • Physica Medica, Vol. XIII, Supplement 1 (1997) 61-63
  • Contribution to external collection
    Fifth Int. Conf. on Applications of Physics in Medicine and Biology, Trieste, Italy, 2-6 Sep, 1996
    Physica Medica, Vol. XII, No. 3 (1996) 157

Publ.-Id: 1197 - Permalink


Ion Beam Synthesis of Cobalt Disilicide Using Focused Ion Beam Implantation
Teichert, J.; Bischoff, L.; Hausmann, S.;
Cobalt disilicid layers were formed by cobalt focused ion beam implantation into silicon. It was found that the CoSi2 layer formation strongly depends on the pixel dwell time. In order to obtain continuous layers, short dwell times of a few µs are needed. Rutherford backscattering and channeling mesuarements were carried out to understand this effect. The results suggest that the accumulated irradiation damage is larger for longer dwell times. The sputtering yield of cobalt ions was measured and the formation of CoSi2 in noncrystalline silicon investigated.
  • Contribution to proceedings
    Proc. Intern. Seminar "Ion Nanobeams and Applications to Material Processing", Osaka, Nov. 16-20, 1997
  • The Journal of Vacuum Science and Technology B 16(4), Jul/Aug 1998, 2574-2577

Publ.-Id: 1195 - Permalink


Isotopically Labelled Humic Acids for Heavy Metal Complexation
Bubner, M.; Pompe, S.; Meyer, M.; Heise, K.-H.; Nitsche, H.;
  • Lecture (Conference)
    Vortrag, Joint European IIS Conference, 24.-26.Juni 1998, Bad Soden
  • Tagungsbericht in J. Labelled Compounds and Radiopharmaceuticals XLI, 1017-1082 (1998)

Publ.-Id: 1194 - Permalink


Magnetic dipole bands in odd indium isotopes built on the pig9/2-1vh11/22 configuration
Frauendorf, S.; Reif, J.;
The structure of the magnetic dipole bands is studied by means of shell-modell
calculations. The calculations correlate with the data, showing a transition
from irregular sequences in the light isotopes to regular bands in the
heavy ones. The analysis of the wave functions reveals a more complex mechanism
of angular momentum generation than in the Pb isotopes: the shears mechanism
of the intruder orbitals and the normal parity neutrons make comparable
contributions.
  • Nuclear Physics A 621 (1997) 736-744

Publ.-Id: 1193 - Permalink


Collective structures and smooth band termination in 109Sn
Käubler, L.; Schnare, H.; Fossan, D. B.; Afanasjev, A. V.; Andrejtscheff, W.; Allatt, R. G.; de Graaf, J.; Grawe, H.; Hibbert, I. M.; Lee, I. Y.; Macchiavelli, A. D.; O'Brien, N.; Maier, K. H.; Paul, E. S.; Prade, H.; Ragnarsson, I.; Reif, J.; Schubart, R.; Thorslund, I.; Vaska, P.; Wadsworth, R.; Winter, G.;
Six rotational bands up to energies Ex=24.7 MeV and spins Jpi=(79/2-)
have been identified in 109Sn using the GAMMASPHERE gamma-detector
array. Four of the bands show smoothly decreasing dynamic moments of inertia
at rotational frequencies hv > 0.6 MeV. The bands arise at medium spins
from coupling of a valence d5/2, g7/2 or h11/2
neutron to the deformed 2p2h proton excitation of the Z=50 core 108Sn.
At very high hv these bands show the typical behaviour of smoothly terminating
bands, i.e. a gradual alignment of the angular momenta of the valence particles
and holes corresponding to a transition from high collectivity to noncollective
states.
  • Z. Phys. A356 (1996) 235-237

Publ.-Id: 1192 - Permalink


Vergleich von berechneten und gemessenen Alpha-Spektren von extrem dünnen Betonmeßpräparaten zur Freigabeentscheidung
Nebelung, C.; Nitsche, H.; Henniger, J.; Mann, G.;
  • Poster
    Vortragstagung der GDCh-Fachgruppe Nuklearchemie 7.-9.9.1998, Dresden, Germany

Publ.-Id: 1191 - Permalink


Physikochemische Charakterisierung der Elemente der 6. Gruppe im O2-H2O(g)/SiO2(s)-System
Hübener, S.; Eichler, B.; Gäggeler, H. W.; Grantz, M.; Jost, D. T.; Nitsche, H.; Taut, S.; Türler, A.; Vahle, A.;
Zur physikochemischen Charakterisierung des Seaborgiums ist die Hochtemperatur-Gaschromatographie im O2-H2O(g)/SiO2(s)-System gut geeignet.
In Thermochromatographieexperimenten mit trägerfreien, langlebigen Nukliden der Sg-Homologen Cr, Mo und W wurde nachgewiesen, daß der Transport von Spurenmengen dieser Elemente im Unterschied zum Transport makroskopischer Mengen einheitlich erfolgt. In trockenem Sauerstoff werden monomere Trioxide gebildet, die über einfache reversible Adsorption durch die Chromatographiesäule transportiert werden. Wegen der geringen Flüchtigkeit dieser Verbindungsklasse kommt eine Charakterisierung des Sg als Trioxid jedoch nicht in Betracht.
In feuchtem Sauerstoff bilden alle drei Sg-Homologen Oxidhydroxide, die reaktionsgaschromatographisch transportiert werden, wobei im adsorbierten Zustand wiederum das Trioxid vorliegt:
MO2(OH)2(g) « MO3(ads) + H2O(g)
Für diese Reaktion wurden thermodynamische Zustandsfunktionen bestimmt, die es erlauben, das Verhalten der Sg-Homologen unter veränderten experimentellen Bedingungen vorauszusagen und Sg-Experimente zu interpretieren.
Modellexperimente im Hinblick auf die physikochemische Charakterisierung des Sg wurden unter Nutzung kurzlebiger, trägerfreier Mo- und W-Isotope mittels isothermer on-line Hochtemperatur-Gaschromatographie durchgeführt. Durch Optimierung der experimentellen Bedingungen und verschiedene methodische Neuentwicklungen gelang es, die Gesamtretentionszeit für W von » 90 s auf » 10 s zu senken. Für 166W mit einer Halbwertszeit von 18,8 s, die etwa der des 266Sg (t1/2 = 21 s) entspricht, wurde eine Maximalausbeute von 53 % erhalten.

Erste Sg-Experimente im O2-H2O(g)/SiO2(s)-System sind für Juni/Juli 1998 geplant. Ergebnisse dieser Experimente sollen vorgestellt und diskutiert werden.
  • Lecture (Conference)
    Vortragstagung FG Nuklearchemie der GDCh 7.-9.9.98 in Dresden

Publ.-Id: 1190 - Permalink


Gas Chromatographic Studies of Oxide and Hydroxide Species of Tungsten - Model Experiments with Respect to the Physico-Chemical Characterization of Seaborgium (Element 106)
Vahle, A.; Eichler, B.; Funke, H.; Hübener, S.; Jost, D. T.; Türler, A.; Brüchle, W.; Jäger, E.;
  • Radiochimica Acta 84, 43-51 (1999)

Publ.-Id: 1189 - Permalink


Comment on "Gettering of Cu by He-Induced Cavities in SIMOX Materials
Yankov, R. A.; Skorupa, W.;
  • Nuclear Instruments and Methods in Physics Research B 149 (1999) 445

Publ.-Id: 1188 - Permalink


Enhancement of the Intensity of the Short-Wavelength Visible Photoluminescence from Silicon-Implanted Silicon-Dioxide Films Caused by Hydrostatic Pressure During Annealing
Tyschenko, I. E.; Rebohle, L.; Yankov, R. A.; Skorupa, W.; Misiuk, A.;
  • Applied Physics Letters, Vol. 73, H. 10, 7. Sept. 1998 S. 1418 - 1420

Publ.-Id: 1187 - Permalink


Homogeneously Size Distributed Ge Nanoclusters Embedded in SiO2 Layers Produced by Ion Beam Synthesis
Markwitz, A.; Rebohle, L.; Skorupa, W.; Hofmeister, H.;
  • Nuclear Instruments and Methods in Physics Research B 147 (1999) 361-366
  • Lecture (Conference)
    E-MRS ´98, Strasbourg, June 16 - 19, 1998

Publ.-Id: 1186 - Permalink


Neues Radiochemisches Laborgebäude des Forschungszentrums Rossendorf - Bauliche und strahlenschutztechnische Aspekte
Friedrich, H.; Bernhard, G.; Nitsche, H.;
  • Poster
    GdCh, Nuklearchemische Tagung, Dresden 7.-9.9.1998

Publ.-Id: 1185 - Permalink


Hardness, Tribological Behaviour and Corrosion Performance at the very Near Surface of Nitrogen Ion-Implanted X5CrNi18.10 Steel
Intarasiri, S.; Yu, L. D.; Chudoba, T.; Reuther, H.; Rammelt, U.; Richter, E.;
  • Surface and Coatings Technology 99 (1998) 305-310

Publ.-Id: 1184 - Permalink


Institute of Radiochemistry; Annual Report 1997
Nitsche, H.; Engelmann, H.-J.; Bernhard, G.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-218

Downloads:

Publ.-Id: 1182 - Permalink


Structural Investigation of the System Ca2+/UO22+/CO32- by EXAFS
Reich, T.; Geipel, G.; Denecke, M. A.; Allen, P. G.; Bucher, J. J.; Edelstein, N. M.; Shuh, D. K.; Bernhard, G.; Nitsche, H.;
  • Other report
    1997 SSRL Annual Activity Report

Publ.-Id: 1180 - Permalink


Gettering of Iron and Oxygen in Helium-Implanted Czochralski (CZ) and Float-Zone (FZ) Silicon
Yankov, R. A.; Kaschny, J. R.; Fichtner, P. F. P.; Mücklich, A.; Kreißig, U.; Danilin, A. B.; Skorupa, W.;
  • Poster
    E-MRS 98, Strasbourg, June 16-19, 1998

Publ.-Id: 1179 - Permalink


Study of Ion Beam Assisted Deposition of Al/AlN Multilayers by Comparison of Computer Simulation and Experiment
Wang, X.; Charlamov, V.; Kolitsch, A.; Posselt, M.; Trushin, Y.; Möller, W.;
  • Journal of Physics D: Applied Physics 31 (1998) 2241-2244

Publ.-Id: 1178 - Permalink


Thermal Dilepton Signal and Dileptons from Correlated Open Charm and Bottom Decays in Ultrarelativistic Heavy-Ion Collisions
Kämpfer, B.; Gallmeister, K.; Pavlenko, O. P.;
  • Book (Authorship)
    Advances in Nuclear Dynamics 4, Edited by W. Bauer and H.-G. Ritter, Plenum Press, New York, 1998, p. 163

Publ.-Id: 1177 - Permalink


Experimentelle Untersuchung turbulenter Flüssigmetall- und Flüssigmetall-Gas-Strömungen in einem äußeren Magnetfeld
Eckert, S.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-219

Downloads:

Publ.-Id: 1175 - Permalink


Investigation of Dwell-Time Effects on the Cobalt Disilicide Formation Using Focused Ion Beam Implantation
Hausmann, S.; Bischoff, L.; Teichert, J.; Grambole, D.; Herrmann, F.; Möller, W.;
The influence of dwell-time effects on the formation of CoSi2 layers was investigated. The layers were produced on Si(111) and Si(100) by ion beam synthesis using a focused ion beam system. The experiments show that the dwell-time has a strong influence on the formation process of the cobalt disilicide films. In order to obtain high quality films suitable for applications short dwell-time (about 1µs) are necessary.
  • Microelectronic Engineering 41/42 (1998) 233-236
  • Lecture (Conference)
    Int. Conf. Micro- and Nano-Engineering, MNE ´97, Athens, Greece, Sept. 15 - 18, 1997

Publ.-Id: 1174 - Permalink


Computer Simulation of Channeling Profile Analysis of Implantation Damage
Posselt, M.;
Channeling profile analysis is simulated using the dynamic binary collision code Crystal-TRIM. A good agreement between theoretical and experimental data is found for silicon targets which were predamaged by Si+ ions of different energies and analyzed by 140 keV B+ ions. For each example the depth profile of the defects relevant for the dechanneling of the analyzing ions is given. An estimation on the annealing of such defects is obtained by comparison of results for as-implanted and annealed samples.
  • Contribution to proceedings
    MRS Symposium Proceedings, Mat. Res. Soc. Symp. Proc. Vol. 532, pp. 133-140, 1998 Materials Research Society
  • Lecture (Conference)
    MRS Spring Meeting, San Francisco, CA, USA, April 13-17, 1998

Publ.-Id: 1172 - Permalink


Interactions of Bacteria from a Uranium Mining Waste Pile with U(VI)
Panak, P.; Miteva, V.; Boudakov, I.; Hard, B. C.; Pietzsch, K.; Kutschke, S.; Selenska-Pobell, S.; Bernhard, G.; Nitsche, H.;
  • Lecture (Conference)
    Uranium Mining and Hydrogeology II, Freiberg, Germany, 15.-17.09.1998
  • Poster
    Uranium Mining and Hydrogeology II, Freiberg, Germany, 15.-17.09.1998

Publ.-Id: 1171 - Permalink


Wechselwirkung von Bakterien aus Uranhalden mit U(VI) und anderen Schwermetallen
Panak, P.; Miteva, V.; Boudakov, I.; Hard, B. C.; Pietzsch, K.; Kutschke, S.; Selenska-Pobell, S.; Bernhard, G.; Nitsche, H.;
  • Lecture (Conference)
    GdCh- Tagung Dresden
  • Poster
    GdCh- Tagung Dresden

Publ.-Id: 1170 - Permalink


Investigation of Bacterial Diversity in Soil of a Depleted Saxonian Uranium Mine via 16S rRNA Gene and 16S/23S Intergenic Spacer Analyses
Puers, C.; Kampf, G.; Selenska-Pobell, S.;
  • Lecture (Conference)
    International Symposium on Microbial Ecology ISME-8, Halifax, Kanada, 9.-14.8.1998
  • Poster
    International Symposium on Microbial Ecology ISME-8, Halifax, Kanada, 9.-14.8.1998

Publ.-Id: 1166 - Permalink


Bacterial Diversity in Soil of a Depleted Saxonian Uranium Mine as Revealed by 16S rRNA Gene and 16S/23S Intergenic Spacer Analyses
Puers, C.; Kampf, G.; Selenska-Pobell, S.;
  • Lecture (Conference)
    Uran-Bergbau und Hydrologie II, Freiberg, 15.-17.9.1998
  • Poster
    Poster auf der ISME-8, Halifax, Kanada, 9.-14.8.1998

Publ.-Id: 1165 - Permalink


Molecular Studies of Bacterial Diversity in Uranium Wastes
Selenska-Pobell, S.; Boudakov, I.; Flemming, K.; Kampf, G.; Kutschke, S.; Miteva, V.; Otto, A.; Puers, C.; Wober, J.;
  • Poster
    Uran-Bergbau und Hydrologie II, Freiberg, 15.-17.9.1998
  • Lecture (Conference)
    Uran-Bergbau und Hydrologie II, Freiberg, 15.-17.9.1998
  • Lecture (Conference)
    8. Internationales Symposium Mikrobielle Ökologie ISME 8, Halifax, Kanada, 9.-14.8.1998
  • Poster
    8. Internationales Symposium Mikrobielle Ökologie ISME 8, Halifax, Kanada, 9.-14.8.1998

Publ.-Id: 1164 - Permalink


Molecular Characterization of Thiobacillus Strains Recovered from Uranium Waste Piles
Kutschke, S.; Selenska-Pobell, S.; Otto, A.; Panak, P.; Geipel, G.; Bernhard, G.; Nitsche, H.;
  • Poster
    Uranium Mining and Hydrology II, Freiberg, Germany, 15.-17.9.1998

Publ.-Id: 1163 - Permalink


Comparison of Desulfovibrio Isolates Recovered from a Uranium Waste Heap and Other Environments
Wober, J.; Flemming, K.; Hard, B. C.; Pietzsch, K.; Selenska-Pobell, S.;
  • Poster
    Uranium Mining and Hydrogeology II, Freiberg, Germany, 15.-17.09.1998
  • Lecture (Conference)
    Uranium Mining and Hydrogeology II, Freiberg, Germany, 15.-17.09.1998
  • Poster
    Euroconference: Bacterial-Metal/Radionuclide Interaction, Rossendorf/Dresden, Germany, 02.-04.12.1998

Publ.-Id: 1162 - Permalink


Investigations of the Structural Changes Ahead of a Crack Tip in Ductile Aluminium Using Scanning Micro-Beam Small Angle X-Ray Scattering
Große, M.; Böhmert, J.; Riekel, C.;
  • J. Material Science Letters 17 (1998) 1631

Publ.-Id: 1161 - Permalink


Anodic Oxidation of the Carbon-14-labelled Organic Waste
Förster, E.; Heise, K.-H.; Nitsche, H.;
Barium carbonate is a widely accepted stable chemical form for the safe disposal of carbon-14. This requires, however, oxidation of carbon-14-containing organic waste to carbon dioxide. We habe developed a method for the mineralization of organic compounds by anodic oxidation in silver-sulfate-containing sulfuric-chromic acid. This process can also be used for complete oxidation of "difficult" organic wastes, such as hydrophobic substances like hydrocarbons, plastics, activated carbon, etc. The generation of additional chromium-containing hazardous wastes are avoided in this process by electrolytically regenerating chromium(III) to chromium(VI). The degradation of C-14 labeled organic compounds during the process is monitored by on-line measurement the β-radiation of the produced 14CO2
  • Poster
    13th Radiochemical Conference, Marianske Lazne, 19.-24.4.1998

Publ.-Id: 1160 - Permalink


Characterization of Aquatic Humic Substances from Bog Water and their Complexation Behavior Toward Uranyl Ions
Schmeide, K.; Zänker, H.; Heise, K.-H.; Nitsche, H.;
The investigation of the effects of humic substances (humic and fulvic acids) on the migration of radionuclides is important to assess their impact on the long-term safety of both radioactive waste repository sites (e.g. Gorleben, Germany) and abandoned uranium mines (Saxony and Thuringia, Germany).
We extracted humic substances from bog water of the 'Hochmoor Kleiner Kranichsee' which is in the vicinity of the uranium mining sites at Johanngeorgenstadt (Saxony). The humic material was separated into humic and fulvic acid fractions and characterized for its elemental composition, functional properties including proton exchange capacity, charge/size distribution ratios and spectroscopic characteristics. The size and size distribution of humic colloids were studied by photon correlation spectroscopy. Furthermore, the complexation of site specific humic substances with uranyl ions was studied. The results were compared with data of a commercial humic acid from Aldrich.
  • Poster
    13th Radiochemical Conference Marianske Lazne 19.-24.4.1998

Publ.-Id: 1159 - Permalink


Modified Synthetic Humic Acids for the Investigation of Humic Acid Complexation Behavior with Urany(IV) Ions
Pompe, S.; Bubner, M.; Heise, K.-H.; Nitsche, H.;
The influence of humic substances on the speciation of actinide ions and their migration behavior in natural aquifer
systems is of great interest within environmental research. Specified knowledge about this is required, for instance, to
develop strategies of risk assessment for long-time safety in the regions of the former uranium mining in Saxony and
Thuringia. Due to the complex and heterogeneous nature of humic substances a thermodynamic founded description of their
complexation behavior with metal ions is difficult. Numerous uncertainties exist in the description of the complexation
process, e.g., the kind and number of complexing functional groups is uncertain. Therefore, it is necessary to
investigate the complexation process with well defined model substances.
We synthesize and characterize humic acid functionality models from reducing sugars and  -amino acids, with functional
properties comparable to those of natural humic acids with respect to type and number of functional groups. Former
measurements have shown that this synthetic humic acids mimic the interaction humic acid - metal ion very well.
This work deals with the possibilities to synthesize modified humic acids, e.g., humic acids with blocked phenolic OH
groups. With this model substances we investigate the influence of phenolic OH groups on the complexation behavior
of humic acids with uranyl ions by time-resolved laser-induced fluorescence spectroscopy. We expect to get a better
understanding of the humic acid - metal ion interaction process and to gather information regarding geochemical
modeling in the presence of humic acids.
  • Poster
    13th Radiochemical Conference Marianske Lazne- Jachymov, 20.-24.04.1998

Publ.-Id: 1158 - Permalink


Melanoidins as Model Humic Acids in Radioecological Research
Heise, K.-H.; Nicolai, R.; Pompe, S.; Bubner, M.; Nitsche, H.;
Natural humic acids are instable and chemically not well defined chemical systems. It is difficult to accurately describe their physical-chemical properties. Therefor, studies of the interaction between humic acids and heavy metals, including uranium and other actinide elements, are often limited by this fact. For systematic studies of the interaction processes, stable and wellcharacterized humic acid model compounds have been suggested.
We have separated humic-acid-like fractions with good chemical stability from synthetic melanoidins. It is possible to design the functionality of these melanoidins by varying their precursor substances and the conditions of the synthesis.
Furthermore, we have compared different melanoidins and their interaction with UO22+ with the behavior of a commercial natural humic acid (Aldrich) jby infrared spectroscopy (FTIR). The investigation reveals many functional similarities between the melanoidins and the natural humic acid. Comparable symmetric deformation vibrations of uranium in the far infrared range (FIR) indicate similar uranium coordination. In the middle infrared range (MIR), the antisymmetric stretching vibrations of the bound uranium are nearly identical.
In connection with other investigations we have shown, that the melanoidins are excellent humic acid model substances for fundamental radioexological research.
  • Poster
    13th Radiochemical Conference, Marienbad, 19.-24.4.1998

Publ.-Id: 1157 - Permalink


Determination of Dissociation Constants of 99mTechnetium Radiopharmaceuticals by Capillary Electrophoresis
Jankowsky, R.; Friebe, M.; Noll, B.; Johannsen, B.;
Capillary electrophoresis was applied to investigate pKa values of 99mTc radiotracers used in nuclear medicine. Therefore, the protonation equilibria of the carboxyl groups of 99mTc- mercaptoacetylglycylglycylglycine (99mTc-MAG3) and 99mTc-ethylenecysteine dimer (99mTc-EC) were studied by pH-dependent determination of electrophoretical velocities. 99methylenecysteine dimer diethyl ester (99mTc-ECD) was used as a non-protonable standard. The capillary electrophoresis system was equipped with a radioactivity detector. Measurements were performed using a pressure-driven capillary zone electrophoresis which allowed runs even in the low pH range. For the determination of pKa values, the electrophoretical velocities of the analytes were referred to the electrophoretical velocities of tetraphenyle arsonium chloride as a positively charged marker. Calculation of pKa values was accomplished by non-linear curve fitting of both structure-based equilibria equations and sigmoidal decay functions to the experimental data. 99mTc-MAG3 was shown to have a carboxyl group pKa value of 4.22. the value for the carboxyl groups of 99mTc-EC is 2.90 (determined by structure-based equilibria equations), which represents a common value for both carboxyl groups. By the use of sigmoidal functions, similar values were elucidated. As expected, 99mTc-ECD shows no protonation step.
Keywords: Dissociation constants; Pharmaceutical analysis, Metal complexes, Technetium
  • Journal Chromatography A, 833 (1999) 83-96

Publ.-Id: 1156 - Permalink


The existence of [ReNF4]- - an EPR study
Voigt, A.; Abram, U.; Kirmse, R.;
  • Inorg. Chem. Communications 1 (1998) 141-142

Publ.-Id: 1155 - Permalink


Anwendung wissensbasierter Methoden auf der Grundlage von Insitu-Messung und qualitativer Modellierung zur Optimierung von Schüttguthandhabungstechniken am Beispiel des Dosierens
Lindau, B.;
  • Other report
    Freiberger Forschungshefte A 841 Grundstoff-Verfahrenstewchnik 1998, Technische Universität Bergakademie Freiberg Partikeltechnologie: Vorträge und Poster zum 49.Berg-und Hüttenmännischen Tag 1998 in Freiberg, S. 325-333
  • Poster
    49.Berg- und Hüttenmännischer Tag 1998 in Freiberg, S. 325-333

Publ.-Id: 1154 - Permalink


Synthesis and Crystal Structures of [TeI3][GaI4] and [TeI3][InI4]
Schulz-Lang, E.; Vasquez-Lopez, E.; Strähle, J.; Abram, U.;
  • Z. anorg. allg. Chem. 624 (1998) 999-102

Publ.-Id: 1153 - Permalink


Tris(selenophenyl)methane
Schulz-Lang, E.; Pradella-Ziani, J.; Abram, U.;
  • Acta Crystallographica (1998) C55, 1010-1011

Publ.-Id: 1152 - Permalink


Reactions of Dichloro[2-(dimethylaminomethyl)phenyl-C1,N]gold(III), [Au(damp-C1,N)Cl2], with heterocyclic thiols. Evidence for Au-N bond cleavage and protonation of the dimethylamino group
Abram, U.; Mack, J.; Ortner, K.; Müller, M.;
  • J. Chem. Soc. Dalton Trans. 1998, Pages 1011-1019

Publ.-Id: 1151 - Permalink


Synthesis, Characterization and Structure of bis{2-[1-(thiosemicarbazono)ethyl]pyridinium}hexanitratothorate(IV)
Abram, U.; Abram, S.;
  • J. Chem. Cryst.

Publ.-Id: 1149 - Permalink


A New Electrode-Mesh Tomograph for Gas-Liquid Flows
Prasser, H.-M.; Böttger, A.; Zschau, J.;
The paper presents an electrode-mesh tomograph for the high-speed visualisation of transient gas fraction distributions in two-phase flows in pipes. It is based on the measurement of the local instantaneous conductivity of the two-phase mixture. The time resolution of the device is 1024 frames per second. The sensor consists of two electrode grids with 16 electrodes each. This results in 16 x 16 sensitive points, which are equally distributed over the cross section. The sensor is available in two designs: (1) wire-mesh sensor for lab applications and (2) sensor with enforced electrode rods for high mechanical loads. The device was recently tested in a vertical and a horizontal air-water flow in a pipe of 51.2 mm diameter.
  • Flow Measurement and Instrumentation 9 (1998) 111-119

Publ.-Id: 1148 - Permalink


Annealing and Recrystallization of Amorphous Silicon Carbide Produced by Ion Implantation
Höfgen, A.; Heera, V.; Eichhorn, F.; Skorupa, W.;
  • Journal of Applied Physics Vol. 84, Number 9, 1. Nov. 1998, pp. 4769-4774
  • Lecture (Conference)
    ECSCRM '98 (2nd European Conf. on Silicon Carbide and Related Materials), Montpellier, Sept. 2 - 4, 1998

Publ.-Id: 1147 - Permalink


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