Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

"Online First" included
Without submitted and only approved publications
Only approved publications

32178 Publications
Multifragmentation of spectators in relativistic heavy-ion reactions
Botvina, A. S.; Mishustin, I. N.; Begemann-Blaich, M.; Hubele, J.; Immé, G.; Iori, I.; Kreutz, P.; Kunde, G. J.; Kunze, W. D.; Lindenstruth, V.; Lynen, U.; Moroni, A.; Müller, W. F. J.; Ogilvie, C. A.; Pochodzalla, J.; Raciti, G.; Rubehn, T.; Sann, H.; Schüttauf, A.; Seidel, W.; Trautmann, W.; Wörner, A.;
  • Nuclear Physics A 584 (1995) pp. 737-756

Publ.-Id: 636 - Permalink


Shears bands in 201Pb and 202Pb
Baldsiefen, G.; Maagh, P.; Hübel, H.; Korten, W.; Chmel, S.; Neffgen, M.; Pohler, W.; Grawe, H.; Maier, K. H.; Spohr, K.; Schubart, R.; Frauendorf, S.; Maier, H. J.;
  • Nuclear Physics A 592 (1995) pp. 365

Publ.-Id: 635 - Permalink


Mining Relics as Sources of Natural Radioactivity - Release of Radon from Uranium Mill Tailings
Baraniak, L.; Mende, A.;
  • Book (Authorship)
    Hrsg.: Winter, M., Wicke, A., "Umweltradioaktivität, Radioökologie und Strahleneinwirkungen" Verlag TÜV Rheinland, 1 (1993) pp. 76

Publ.-Id: 634 - Permalink


Characterisation of Oxide Layers Formed by Hydrothermal Chromate Treatment
Thieme, M.;
  • Corros. Sci. 34 (1993) pp. 1557

Publ.-Id: 633 - Permalink


Transformation of Titanium Carbide Precipitations under Hydrothermal Conditions
Thieme, M.; Scharnweber, D.; Stephan, T.;
  • Corros. Sci. 34 (1993) pp. 383

Publ.-Id: 632 - Permalink


The Hydrothermal Chromate Treatment of Carbon Steel. The Electrochemical and Surface Analytical Characterisation of Protecting Oxide Layers
Thieme, M.; Scharnweber, D.;
  • Corros. Sci. 34 (1993) pp. 363

Publ.-Id: 631 - Permalink


Degradation of 3,3',4,4'-Tetrachlorobiphenyl by selected white rot fungi
Vyas, B. R. M.; Sasek, V.; Matucha, M.; Bubner, M.;
  • Chemosphere 28 (1994) 6 pp. 1127-34

Publ.-Id: 630 - Permalink


The effects of radiolysis upon speciation and solubility of neptunium in brine solutions
Silber, H. B.; Nitsche, H.; Gatti, R. C.; Gehmecker, H.; Feige, G.; Bucher, J. J.; Edelstein, N. M.;
  • Radiochimica Acta 66/67 (1994) pp. 15

Publ.-Id: 629 - Permalink


Near-threshold behavior of the K-shell satellites in CO
Reich, T.; Heimann, P. A.; Petersen, B. L.; Hudson, E. A.; Hussain, Z.; Shirley, D. A.;
  • Physical Review A 49 (1994) 6 pp. 4570-77

Publ.-Id: 628 - Permalink


Long term plutonium solubility and speciation studies in a synthetic brine
Nitsche, H.; Roberts, K.; Xi, R.; Prussin, T. G.; Becraft, I.; Mahamid, A.; Silber, H. B.; Carpenter, S. A.; Gatti, R. C.;
  • Radiochimica Acta 66/67 (1994) pp. 3

Publ.-Id: 627 - Permalink


Comparison of chemical extractions and laser photoacoustic spectroscopy for the determination of plutonium species in carbonate solution
Neu, M. P.; Hoffmann, D. C.; Roberts, K.; Nitsche, H.; Silva, R. J.;
  • Radiochimica Acta 66/67 (1994) pp. 251

Publ.-Id: 626 - Permalink


Structural Investigations on Pyrolysed Polycarbosilanes
Martin, H. P.; Irmer, G.; Schuster, G.; Müller, E.;
  • Fresenius' Journal of Analytical Chemistry 349 (1994) pp. 160

Publ.-Id: 625 - Permalink


Thermochromatographic studies of heavy actinides in metal columns
Hübener, S.; Eichler, B.; Gäggeler, H. W.;
  • Journal of Alloys and Compounds 213/214 (1994) pp. 429

Publ.-Id: 624 - Permalink


Toward a soft x-ray fourier-transform spectrometer
Howells, M. R.; Frank, K.; Hussain, Z.; Moler, E. J.; Reich, T.; Möller, D.; Shirley, D. A.;
  • Nuclear Instruments and Methods in Physics Research A 347 (1994) pp. 182-191

Publ.-Id: 623 - Permalink


Neutron and X-Ray Investigations on the Oxygen Bonding in YBa2Cu3O7-x combined with Physico-chemical Methods
Große, M.; Schuster, G.; Teske, K.; Anwand, W.; Henkel, K.;
  • Fresenius' Journal of Analytical Chemistry 349 (1994) pp. 231-233

Publ.-Id: 622 - Permalink


Distribution of uranium and radionuclides in a uranium-mining rockpile in Schlema, Saxony, Germany
Geipel, G.; Thieme, M.; Bernhard, G.; Nitsche, H.;
  • Radiochimica Acta 66/67 (1994) pp. 305
  • Poster
    Migration '95

Publ.-Id: 621 - Permalink


Synthesis of the 14C-labelled juwenoid W 328
Ebert, T.; Havlicek, L.; Wimmer, Z.; Bubner, M.;
  • Journal of Labelled Compounds and Radiopharmaceuticals XXXIV, 377 (1994)

Publ.-Id: 620 - Permalink


Operating and strategy for the decommissioning of the radiochemical plant AMOR-I
Bernhard, G.; Friedrich, H.-J.; Boeßert, W.; Eckardt, A.;
  • Kerntechnik 59 (1994) 3 pp.135

Publ.-Id: 619 - Permalink


Thermochromatographic Studies of Oxide and Hydroxide Species of Molybdenum - Model Experiments with Respect to the Physico-chemical Characterization of Element 106
Vahle, A.; Hübener, S.; Eichler, B.;
  • Radiochimica Acta 69 (1995) pp. 233

Publ.-Id: 618 - Permalink


Environmental Applications of XANES: Speciation of Tc in Cement after Chemical Treatment and Se after Bacterial Uptake
Shuh, D. K.; Kaltsoyannis, N.; Bucher, J. J.; Edelstein, N. M.; Clark, D. L.; Nitsche, H.; Reich, T.; Hudson, E. A.; Mahamid, A.; Torretto, P.; Lukens, W. W.; Roberts, K.; Yee, B. C.; Carlson, D. E.; Yee, A.; Buchanan, B. B.; Leighton, T.; Yang, W.-S.; Bryan, J. C.;
  • Mater. Res. Soc. Symp. Proc. 344 (1995)

Publ.-Id: 617 - Permalink


X-Ray Photoelectron Study of the Interaction of UO2(CIO4)2 with Calcite Diabase Minerals in Water Solutions
Teterin, Y. A.; Nefedov, V. I.; Ivanov, K. E.; Baev, A. S.; Geipel, G.; Reich, T.; Nitsche, H.;
  • Dokl. Akademii Nauk 344 (1995) pp. 206 (in Russian)
  • Surface Investigations 13, 613 (1998)

Publ.-Id: 616 - Permalink


Synchrotron X-ray Absorption Spectroscopy: a New Tool for Actinide and Lanthanide Speciation in Solids and Solution
Nitsche, H.;
  • Journal Alloys and Compounds 223 (1995) pp. 274

Publ.-Id: 615 - Permalink


Silicon Carbide Derived from Silica Sol and Sugar
Martin, H. P.; Müller, E.; Knoll, Y.; Strienitz, R.; Schuster, G.;
  • Journal of Materials Science Letters 14 (1995) pp. 620

Publ.-Id: 614 - Permalink


A XANES and EXAFS Investigation of the Speciation of Selenite following Bacterial Metabolization
Buchanan, B. B.; Bucher, J. J.; Carlson, D. E.; Edelstein, N. M.; Hudson, E. A.; Kaltsoyannis, N.; Leighton, T.; Lukens, W. W.; Shuh, D. K.; Nitsche, H.; Reich, T.; Roberts, K.; Torretto, P.; Woicik, J.; Yang, W.-S.; Yee, A.; Yee, B. C.;
  • Inorganic Chemistry 34 (1995) pp. 1617

Publ.-Id: 613 - Permalink


Complexation of plutonium(V) with nitrilotracetic acid
Mahamid, A.; Becraft, I.; Nitsche, H.;
  • Radiochimica Acta 68 (1995) pp. 63

Publ.-Id: 612 - Permalink


Electronic and Structural Investigations of Technetium Compounds by X-ray Absorption Spectroscopy
Mahamid, A.; Bryan, J. C.; Bucher, J. J.; Burrell, A. K.; Edelstein, N. M.; Hudson, E. A.; Kaltsoyannis, N.; Lukens, W. W.; Shuh, D. K.; Nitsche, H.; Reich, T.;
  • Inorganic Chemistry 34 (1995) pp. 193

Publ.-Id: 611 - Permalink


Multinuclear NMR, Raman, EXAFS, and X-ray diffraction studies of uranyl carbonate complexes in near-neutral aqueous solution. X-ray structure of [C(NH2)3]6[(UO2)3(CO3)6].cntdot.6.5H2O
Allen, P. G.; Bucher, J. J.; Clark, D. L.; Edelstein, N. M.; Ekberg, S. A.; Gohdes, J. W.; Hudson, E. A.; Kaltsoyannis, N.; Lukens, W. W.; Neu, M. P.; Palmer, P. D.; Reich, T.; Shuh, D. K.; Tait, C. D.; Zwick, B. D.;

Publ.-Id: 610 - Permalink


Theoretische Modellierung des Druckbehälters und der Druckbehältereinbauten eines Siedewasserreaktors (SWR), Abschlußbericht
Altstadt, E.; Scheffler, M.; Weiß, F.-P.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-147 (nur für den internen dienstlichen Gebrauch), August 1996

Publ.-Id: 609 - Permalink


Modifizierung mechanischer und korrosiver Oberflächeneigenschaften von Magnesium durch Ionenimplantation
Chudoba, T.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-143 (Dissertation an der Fakultät Mathematik und Naturwissenschaften der TU Dresden)

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Publ.-Id: 608 - Permalink


Synthesis of "3+1"-mixed-ligand oxorhenium(V) complexes containing modified 3,17ß-Estradiol
Wüst, F.; Spies, H.; Johannsen, B.;
  • Bioorganic and Medicinal Chemistry Letters 6 (1996) 22 pp.2729-2734

Publ.-Id: 607 - Permalink


Layered structure diagnostic and optical modelling of c-BN
Plass, M.; Fukarek, W.; Kolitsch, A.; Möller, W.;
  • Nuclear Instruments and Methods in Physics Research B 127/128 (1997) 857

Publ.-Id: 606 - Permalink


The nuclear liquid-gas phase transition: Present status and future perspectives
Pochodzalla, J.; Immé, G.; u. a.; Begemann-Blaich, M.; u. a.; Möhlenkamp, T.; Seidel, W.; Kunze, W. D.; Schüttauf, A.; Kunde, G. J.; u. a.; Bassini, R.; u. a.; Trzcinski, A.; Zwieglinski, B.;
  • Other report
    GSI-Preprint-96-31

Publ.-Id: 605 - Permalink


LAST MINUTE FROM ALADIN: Temperature measurements in Au+Au reactions at relativistic energies
Immé, G.; u. a.; Begemann-Blaich, M.; u. a.; Möhlenkamp, T.; Seidel, W.; Kunze, W. D.; Schüttauf, A.; Pochodzalla, J.; Kunde, G. J.; Gaff, S.; Bassini, R.; u. a.; Trzcinski, A.; Zwieglinski, B.;
  • Other report
    GSI-Preprint-96-30, Juli 1996

Publ.-Id: 604 - Permalink


Determination of critical exponents in nuclear systems
Müller, W. F. J.; u. a.; Bassini, R.; u. a.; Blaich, T.; Immé, G.; u. a.; Kunze, W. D.; u. a.; Möhlenkamp, T.; Seidel, W.; Trzcinski, A.; u. a.;
  • Other report
    GSI-Preprint-96-29

Publ.-Id: 603 - Permalink


Universaly of Spectator Fragmentation at Relativistic Bombarding Energies
Schüttauf, A.; u. a.; Kunze, W. D.; u. a.; Blaich, T.; Bowman, D. R.; u. a.; Charity, R. J.; u. a.; Cosmo, A.; u. a.; Ferrero, A.; u. a.; Immé, G.; u. a.; Möhlenkamp, T.; Seidel, W.; Trzcinski, A.; u. a.;
  • Other report
    GSI-Preprint-96-26, Juni 1996
  • Nuclear Physics A 607 (1996) pp. 457-486

Publ.-Id: 602 - Permalink


Focused ion beam system with high current density
Bischoff, L.; Hesse, E.; Janssen, D.; Naehring, F.; Nötzold, F.; Schmidt, G.; Teichert, J.;
The project of the IMSA-100 focused ion beam system is presented. The main goal of the system is to archieve an ion current density > 10 A/cm2. The ion-optical column consists of a liquid metal ion source, two electrostatic lences, beam blanking plates, and two octupole stigmators. A lithium ion source has been developed.
  • Microelectronic Engineering 13 (1991) pp. 367-370

Publ.-Id: 601 - Permalink


High current FIB system for micromechanics application
Bischoff, L.; Hesse, E.; Hofmann, G.; Naehring, F.; Probst, W.; Schmidt, B.; Teichert, J.;
A high current Focused Ion Beam (FIB) system, designd to achieve current dendities above 10 A/cm2 is presented. The system parameters and properties are discussed and first applications in the field of micromechanics are shown.
  • Microelectronic Engineering 21 (1993) pp. 197-200

Publ.-Id: 600 - Permalink


Measurement of the cerebral uptake and meta-bolism of L-6-[18F]Fluoro-3,4-dihydroxyphenylalanine (18FDOPA) in newborn piglets
Brust, P.; Bauer, R.; Bergmann, R.; Walter, B.; Steinbach, J.; Füchtner, F.; Will, E.; Linnemann, H.; Obert, M.; Zwiener, U.; Johannsen, B.;
  • Book (Authorship)
    Neurochemistry: Cellular, Molecular, and Clinical Aspects, Book Article, Plenum Publishing Cooperation, Section 43: PET Imaging of Receptors;1149-1155

Publ.-Id: 599 - Permalink


A new type of band crossing at large deformation
Harder, A.; Dönau, F.; Lieb, K. P.; Cunningham, R. A.; Gelletly, W.; Gross, C. J.; Hannachi, F.; Kabadiyski, M. K.; Roth, H. A.; Rudolph, D.; Simpson, J.; Skeppstedt, Ö.; Varley, B. J.; Warner, D. D.;
  • Physics Letters B 374 (1996) pp. 277-282

Publ.-Id: 597 - Permalink


Optimization on Rugged Landscapes: A New General Purpose Monte Carlo Approach
Dittes, F.-M.;
  • Physical Review Letters 76 (1996) 25 pp. 4651-55

Publ.-Id: 596 - Permalink


First Observation of the Scissors Mode in a Gamma-Soft Nucleus: The Case of 196Pt
von Brentano, P.; Eberth, J.; Enders, J.; Esser, L.; Herzberg, R.-D.; Huxel, N.; Meise, H.; von Neumann-Cosel, P.; Nicolay, N.; Pietralla, N.; Prade, H.; Reif, J.; Richter, A.; Schlegel, C.; Schwengner, R.; Skoda, S.; Thomas, H. G.; Wiedenhöver, I.; Winter, G.; Zilges, A.;
A nuclear resonance fluorescence experiment with one of the newly developed
highly efficient EUROBALL cluster detectors has been performed on the gamma-soft
nucleus 196Pt. Magnetic dipole excitations were observed between
2 and 3.5 MeV excitation energiy. They are interpreted as the main fragments
of the scissors mode based on the measured excitation strengths and branching
ratios. A strong gamma decay, which we believe to be an E2 decay of the
scissors mode to the 21+ state, is observed. It allows
an extraction of the effective boson quadrupole charges in the interacting
boson model.
  • Physical Review Letters 76 (1996) 12 pp. 2029-32

Publ.-Id: 595 - Permalink


Bericht der Frühjahrstagung der Studiengruppe für Elektronische Instrumentierung vom 25. bis 27. März 1996 in Karlsruhe
Gabriel, F.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-141

Downloads:

Publ.-Id: 594 - Permalink


Plasma source ion implantation of oxygen and nitrogen in aluminum
Günzel, R.; Wieser, E.; Richter, E.; Steffen, H. J.;
  • Journal of Vacuum Science and Technology Part B 12 (1994) 2

Publ.-Id: 593 - Permalink


Added Stiffness Relating to Small Motions of Two Concentric Cylinders Submitted to Axial Annular Incompressible Flow
Zoller, J.;
Abstract
Axial incompressible, viscous flow is considered in an annular gap between two rigid cylinders. If the cylinders are displaced from their concentric positions in a certain manner, the displacement will cause reaction forces exerted by the fluid pressure. In this investigation the pressure fluctuations caused by the displacement of the structures are approximated by analytical means. Pressure fluctuations in phase with acceleration and velocity of the structure are not calculated here. Stationary flow is considered, because structural displacements are assumed to be small.
  • Open Access LogoForschungszentrum Rossendorf; FZR-146 August 1996

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Publ.-Id: 592 - Permalink


Schwankungen des Massenstroms bei Druckentlastungsvorgängen
Lucas, D.; Prasser, H.-M.;
Bei der linearen Stabilitätsanalyse des Abblaseprozesses aus Druckbehältern mit zweiphasigem, aufwallendem Medium wurden Instabilitätsbereiche mit starken Massenstrompulsationen in der Abblaseleitung gefunden. Entscheidender Mechanismus ist die Rückkopplung zwischen Gemischspiegelschwankung, kritischer Ausströmrate und Druckabfallgeschwindigkeit. Für die Stabilitätsanalyse wurden analytische Modelle zur Beschreibung des šbertragungsverhaltens aufgestellt. Es wurden Nyquist-Diagramme für verschiedene Parameterkombinationen untersucht und so die Instabilitätsbereiche identifiziert. Die Schwingneigung wird durch hohe Gasgehalte an der Entlastungsarmatur, eine große Verzögerungszeit (Länge der Abblaseleitung) und geringe Höhen der Schaumzone befördert.
  • Lecture (Conference)
    3. Fachtagung "Anlagen-, Arbeits- und Umweltsicherheit", Köthen, 7.-8.11.1996
  • Contribution to proceedings
    3. Fachtagung "Anlagen-, Arbeits- und Umweltsicherheit", Köthen, 7.-8.11.1996, Preprints, S. 233-240

Publ.-Id: 591 - Permalink


Investigations of an externally heated storage vessel
Aszodi, A.; Liewers, P.; Krepper, E.; Prasser, H.-M.;
Storage tanks for fluids are widely used industrial facilities. As a consequence of an external fire, the heat-up of the inventory may lead to the evaporation of the liquid and to release of significant quantities of dangerous gases into the environment. Experimental investigations performed in FZ-Rossendorf have shown that the liquid inventory behaves very differently depending on the mode of heating. Bottom heating leads to an irregular thermoconvective motion of the liquid, which causes good mixing, so that saturation is reached at all places inside the tank approximately at the same time. The maximum enthalpy of the liquid always remains close to the average value. If the vessel is heated from the side, a stable temperature stratification is observed leading to large temperature gradients. Evaporation can start much earlier than the average temperature reaches saturation.
In order to clarify the physical nature of the details of the heating-up and the evaporation process in simple geometrical boundary conditions a two-dimensional mathematical model was developed, which includes also evaporation and two-phase flow. The aim of the simulations was, to understand the basic phenomena observed during the experiment.
To avoid fast temperature increase at the fluid surface in the case of side wall heating, the insertion of baffle plates inside the vessel was investigated by additional calculations using the CFD-code CFX-4.
  • Poster
    3. Fachtagung "Anlagen-, Arbeits- und Umweltsicherheit", Köthen, 7.-8.11.1996, Tagungsband S.251 - 258
  • Contribution to proceedings
    3. Fachtagung "Anlagen-, Arbeits- und Umweltsicherheit", Köthen, 7.-8.11.1996, Tagungsband S.251 - 258

Publ.-Id: 590 - Permalink


Anwendung neuronaler Netze zur Identifizierung gefährlicher Betriebszustände in Chemieanlagen
Hessel, G.; Schmitt, W.; van der Vorst, K.; Weiß, F.-P.;
  • Other report
    Preprint - GVC / VDI Fachtagung in Köthen, 7. - 8. November 1996, S. 141-147

Publ.-Id: 589 - Permalink


Thermal dilepton and open charm signals versus hard initial yields in heavy-ion collisions at RHIC and LHC energies
Kämpfer, B.; Pavlenko, O. P.;
Abstract
The hard initial production of open charm and dileptons is compared with possible thermal signals in heavy-ion collisions at RHIC and LHC energies. Our approach is based on the perturbative QCD mini-jet mechanism of quark-gluon matter formation. The thermal dilepton signal is found to rise much stronger as compared to the hard Drell - Yan background with increasing collider energy and clearly dominates at LHC energy. Oppositely, open charm stems from initial hard production. A possible rnanifestation of gluon shadowing at RHIC and LHC energies is discussed.
  • Open Access LogoForschungszentrum Rossendorf; FZR-144 Preprint
  • Physics Letters B 391 (1997) pp. 185-190

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Publ.-Id: 588 - Permalink


Retropane - a new Rhenium-Complex as a potential Ligand to label the Dopamin-Transporter
Hoepping, A.; Spies, H.; Johannsen, B.;
  • Bioorganic and Medicinal Chemistry Letters 6 (1996) 23 pp. 2871-2874

Publ.-Id: 587 - Permalink


Technetium and Rhenium Complexes with Thioether Ligands, 5 Synthesis and Structural Characterization of Neutral Oxorhenium (V) Complexes with Tridentate Dithioethers
Pietzsch, H.-J.; Reisgys, M.; Spies, H.; Leibnitz, P.; Johannsen, B.;
  • Chemische Berichte, Recueil 1997, 130, 357-361

Publ.-Id: 586 - Permalink


Comparison of measured and calculated dose for plasma source ion implantation into 3-D objects
Mändl, S.; Barradas, N.; Brutscher, J.; Günzel, R.; Möller, W.;
  • Nuclear Instruments and Methods in Physics Research B 127/128 (1997) 996-999

Publ.-Id: 585 - Permalink


Pulsationen bei der Druckentlastung von Reaktoren
Lucas, D.;
During two-phase blowdown from pressure vessels considerable pulsations of the discharged mass flow rate were found. Regions of instability were predicted by a linear stability analysis. The oscillations are caused by the following feedback circuit: boil up - level movement - void fraction of the discharging mixture - critical discharge rate - velocity of pressure decrease - boil up.
  • Lecture (Conference)
    ACHEMA '97, Frankfurt/M., 9.-14.6.1997

Publ.-Id: 583 - Permalink


Messung der Volumenströme Gas und Flüssigkeit in einer Zweiphasenströmung mit Ultraschall und Mustererkennung
Kossok, N.; Prasser, H.-M.; Schütz, P.;
  • Lecture (Conference)
    Kraftwerkstechn. Kolloquium 1996, Dresden, 29.-30.10.96
  • Contribution to proceedings
    Kraftwerkstechnisches Kolloquium, Dresden, 29. -30. Oktober 1996, Tagungsband S. 121

Publ.-Id: 582 - Permalink


Verhalten von Lagertanks bei externem Feuer
Krepper, E.; Aszodi, A.;
Wenn ein zylindrischer Lagertank durch ein externes Feuer von der Seite intensiver Wärmeeinwirkung ausgesetzt ist, so setzt der Massenverlust infolge von Dampffreisetzung viel eher ein, als im Fall einer Wärmezuführung vom Behälterboden. Mittels eines vereinfachten Modells konnten die Details des Erwärmungsprozesses und die Ursachen für das unterschiedliche Verhalten in Abhängigkeit von der Art und Weise der Wärmezufuhr erklärt werden. Die ZUfuhr vom Boden führt zu einer irregulären thermischen Konvektion und damit einer guten Durchmischung des Fluids, so daß die Sättigungstemperatur an allen Punkten im Behälter nahezu gleichzeitig erreicht wird. Die maximale Enthalpie im Behälter verbleibt während der gesamten Zeit nahe dem Mittelwert. Wird der Behälter von der Seite beheizt, so bildet sich eine stabile horizontale Temperaturschichtung heraus. Die Bildung von Dampf erfolgt bereits lange bevor die mittlere Temperatur den Siedepunkt erreicht hat. Passive konstruktive Maßnahmen, wie der Einbau von Prallplatten, können die Schichtung stören, das verstärkte Aufheizen an der Oberfläche vermeiden und die Freisetzung von Dampf verzögern. Eine durchgreifende Vermischung des flüssigen Inhalts konnte jedoch nicht erreicht werden. Die genaue Gestalt und die Wirkung dieser Prallplatten hängt von der konkreten Behältergeometrie ab und läßt sich weiter optimieren.
  • Lecture (Conference)
    ACHEMA '97, Frankfurt/M., 9.-14.6.1997

Publ.-Id: 581 - Permalink


Untersuchung von Zweiphasenströmungen gasförmig / flüssig mit Positronenemittern
Hensel, F.;

Die Methode der Positronen-Emissions-Tomographie (PET, Positron Emission Tomography) wird zur Untersuchung von Zweiphasenströmungen flüssig / gasförmig angewandt. PET ist ein bildgebendes Verfahren, das für die Nuklearmedizin entwickelt wurde. Im medizinischen Bereich wird diese Technik hauptsächlich als nichtinvasives Untersuchungsverfahren für die quantitative Erfassung von Stoffwechselvorgängen in-vivo genutzt. Die hier vorgestellten Untersuchungen zur Methodik der Anwendung von Radiotracern für Strömungsuntersuchungen wurden 1994 begonnen. Das Ziel der Arbeiten war die örtlich und zeitlich aufgelöste Erfassung von Vermischungs- und Transportprozessen sowie die Messung der Dichte von zweiphasigen Medien. Zur Dichtemessung wurde die Abhängigkeit der Positronenreichweite von der Dichte des Materials ausgenutzt. Bei den entsprechenden Experimenten kam eine örtlich fixierte Positronenquelle (45Ti) zum Einsatz. Desweiteren wurden Messungen zum Stofftransport in Blasenströmungen durchgeführt, hier wurden flüssige Tracer mit dem Nuklid 18F eingesetzt.

  • Lecture (Conference)
    XXVIII. Kraftwerkstechnisches Kolloquium und 6. Kolloquium Meßtechnik für Energieanlagen 1996, Dresden, 29.-30.10.96
  • Contribution to proceedings
    in Kaiser, E.; Nöther, K. (Hrsg): Meßtechnik zur Untersuchung von Vorgängen in thermischen Energieanlagen. Tagung Dresden, 29./30. Oktober 1996. Beitragsmanuskripte Bd. 1 S. 101. ISBN 3-86005-168-7
  • Poster
    XXVIII. Kraftwerkstechnisches Kolloquium und 6. Kolloquium Meßtechnik für Energieanlagen 1996, Dresden, 29.-30.10.96

Publ.-Id: 580 - Permalink


Determination of Crack-Initiation Toughness by Impact and Dynamic Testing
Richter, H.; Böhmert, J.; Viehrig, H.-W.;
The critical J-integral (Jid) can be useful as toughness parameter at initiation of stable crack growth. Under the condition of the impact bending test the critical step for evaluating of Jid is the detection of the crack initiation point on the impact load displacement curve. In this paper the crack initiation is determined by using emission of acoustic waves (AE). The experimental techniques used to evaluate Jid include both instrumented impact testing based on 300 J pendulum impact tester with a piezoelectric broadband AE sensor within the impact tup and dynamic 3 point bending loading with a servohydraulic test machine and additional AE sensors on the specimen.
Different kind of pulses of the AE signals can be observed. One of them corresponds with crack initiation. The evidence of initiation at this point was confirmed by single and multiple specimen methods.
  • Lecture (Conference)
    Proc. of the 11th European Conference on Fracture - ECF 11, Poitiers-Futurscope, France, Sept. 1996, Vol. III, pp. 2001 - 2006
  • Contribution to proceedings
    Proc. of the 11th European Conference on Fracture - ECF 11, Poitiers-Futurscope, France, Sept. 1996, Vol. III, pp. 2001 - 2006

Publ.-Id: 579 - Permalink


DYN3D - A 3-DIMENSIONAL CORE MODEL FOR STEADY STATE AND TRANSIENT ANALYSIS IN THERMAL REACTOR
Grundmann, U.; Rohde, U.;
The 3D core model DYN3D developed firstly for analyses of transients in thermal reactors with hexagonal fuel assemblies was extended by a new version DYN3D/R for reactors with quadratic fuel elements. The method used in Cartesian geometry is described. Numerical results for benchmarks as the NEACRP rod ejection benchmarks are compared with the reference solutions. Results of uncontrolled withdrawal of control rod bank are shown. The efficiency of steady-state neutronic calculation by using multiprocessor workstation is presented.

  • Lecture (Conference)
    Int. Conf. on Physics of Reactors, 16.-20.9.1996, Mito, Japan, Proceedings pp. J-70 - J-79
  • Contribution to external collection
    Int. Conf. on Physics of Reactors, 16.-20.9.1996, Mito, Japan, Proceedings pp. J-70 - J-79

Publ.-Id: 578 - Permalink


Preparation and Characterization of Novel Mixed-Ligand Complexes Bearing up to Four Ester Groups
Seifert, S.; Hoepping, A.; Klostermann, K.; Spies, H.; Johannsen, B.;
  • Applied Radiation and Isotopes, 48 (1997) 943-948

Publ.-Id: 577 - Permalink


Diphoton rates from thermalized matter resulting in ultra-relativistic heavy-ion collisions
Hentschel, M.; Kämpfer, B.; Pavlenko, O. P.; Redlich, K.; Soff, G.;
Abstract
Diphoton radiation off strongly interacting matter resulting from ultrarelativistic heavy-ion collisions is estimated for SPS and RHIC conditions. At SPS emrgies tha thermal diphoton signal competes strongly with the Drell - Yan like background. For given charged-particle rapidity density a scenario with deconfinement transition predicts a larger diphoton yield than a scenario without phase transition. For RHIC energies we find that radiation from initially undersaturated (but gluon-rich) deconfined matter overwhelms the hadron gas and the Drell - Yan like diphotons in the invariant mass window 1 < M < 2.5 GeW. Due to this the so-called M1 scaling is approximately obtained and can serve as additional tsol for discriminating radiation from quark-gluon matter.
  • Open Access LogoForschungszentrum Rossendorf; FZR-142 Preprint
  • Other report
    GSI-Preprint-96-37, August 1996
  • Z. Phys. C 75, 333-339 (1997)

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Publ.-Id: 576 - Permalink


Can hexadecapole deformation lead to Delta I = 2 staggering in superdeformed bands?
Dönau, F.; Frauendorf, S.; Meng, J.;
  • Physics Letters B 387(1996) pp. 667-672

Publ.-Id: 574 - Permalink


Abbau Polychlorierter Biphenyle (PCB) in Pflanzen und bei Kompostierungsprozessen - Untersuchungen mit [14C]PCB Nr. 77
Bubner, M.; Bock, C.; Kolb, M.; van Raaij, E.; Bruhn, G.; Heise, K.-H.; Nitsche, H.; Harms, H.; Förster, U.;
  • Poster
    Gesellschaft Deutscher Chemiker, 7.-10.10.1996, Ulm

Publ.-Id: 573 - Permalink


Interaction of Uranium (VI) with Silicon Species in aqueous Solutions
Moll, H.; Geipel, G.; Reich, T.; Brendler, V.; Bernhard, G.; Nitsche, H.;
  • Poster
    NRC4-Konferenz in St. Malo (Frankreich) 8.-13.9.1996

Publ.-Id: 572 - Permalink


Radium Sorption on Sandy and Clayey Sediments of the Upper Saxon Elbe River Valley
Baraniak, L.; Thieme, M.; Funke, H.; Bernhard, G.; Nindel, K.; Schreyer, J.; Nitsche, H.;
The interaction of radium with characteristic sediments of the upper Saxon Elbe river valley was investigated with a two-fold aim: to provide key data for transport modelling within the framework of mining site restoration and to study the influence of barium-radium-sulfate coprecipitation on the radium adsorption behaviour. For this purpose sorption measurements were carried out on site-specific sediments (different kinds of sandstone, claystone and lime marl) using (1) original low-mineralized groundwater of this area, (2) typical acidic mine water coming from sulfuric acid residues of a former in-situ leaching process (~3 g/L SO42-, pH _ 2.5) and (3) groundwater which was contaminated by 2% mine water. The distribution ratios (Rd) were determined by batch experiments using an 8 weeks' equilibration at aquifer temperature (14C).

Radium sorption from pure and slightly contaminated groundwater onto limonite-rich turonian sandstone is characterized by relatively low distribution ratios (60-180 mL/g). When contacted with mine water, the sorption was enhanced by more than 20-fold compared to the pure and contaminated groundwaters. For the typical lime marl, the strongest sorption occured from the groundwater (390-520 mL/g) and a slightly reduced sorption took place from the acidic mine water.

In addition, the radium sorption was studied as a function of the Ba2+ and SO42- concentration. The results were discussed in terms of the ion product and the solubility product. Conclusions were drawn regarding the predominant sorption mechanisms: coprecipitation, surface complexation and ion exchange.

The long-term migration behaviour in the aquifers of the south-east Saxon Elbe basin was calculated on the basis of Hadermanns' equation, considering convection, dispersion, retardation and radioactive decay.

  • Lecture (Conference)
    4 th International Conference on Nuclear and Radiochemistry, Saint Malo, France, Sept.8-13, 1996

Publ.-Id: 571 - Permalink


Uranium (VI) Sulfate Complexation studied by Time-Resolved Laser-Induced Fluorescence Spectroscopy (TRLFS)
Geipel, G.; Brachmann, A.; Brendler, V.; Bernhard, G.; Nitsche, H.;
  • Radiochimica Acta 75, 199-204 (1996)

Publ.-Id: 570 - Permalink


Nanometre-sized Silver Halides Entrapped in SiO2 Matrices
Matz, W.; Pham, T.; Mücklich, A.;
The formation of nanocrystals after implantation of silver
alone as well as together with the halogen ions Cl, Br, and I into a SiO2
layer of about 100 nm was studied by X-ray diffraction and transmission
electron microscopy. The co-implantation of Ag and Cl/Br results in the
formation of cubic AgX-crystals which are stable in size under annealing.
The co-implantation of Ag and I as well as single Ag implantation result
in Ag crystallites, which grow under annealing. The annealing procedure
causes a redistribution of the particles within the layer.
  • Journal of Materials Science 33 (1998) 155-159

Publ.-Id: 569 - Permalink


Positronen-Emissions-Tomographie bei der Schwerionentherapie. Ein Verfahren zur in-situ Kontrolle der Tumorbehandlung mit Strahlen schwerer Ionen
Enghardt, W.;
  • Physikalische Blätter 52 (1996) 9 pp. 874-875

Publ.-Id: 568 - Permalink


Radiation damage and annealing behaviour of Ge+ -implanted SiC
Pacaud, Y.; Stoemenos, J.; Brauer, G.; Yankov, R. A.; Heera, V.; Voelskow, M.; Kögler, R.; Skorupa, W.;
In recent years, single crystal SiC has become an important electronic material due to its excellent physical and chemical properties. The present paper reports a study of the defect reduction and recrystallization during annealing of Ge+-implanted 6H-SiC. Implants have been performed at 200 keV with doses of 1x1014 and 1x1015 cm-2. Furnace annealing has been carried out at temperatures of 500 °C, 950 °C and 1500 °C. Three analytical techniques including Rutherford backscattering spectrometry in conjunction with channelling (RBS/C), positron annihilation spectroscopy (PAS) and cross-sectional transmission electron microscopy (XTEM) have been employed for sample characterization. It has been shown that damage removal is more complicated than in ion-implanted Si. The recrystallization of amorphized SiC layers has been found to be unsatisfactory for temperatures up to 1500 °C. The use of ionbeam-induced epitaxial crystallization (IBIEC) has been more successfull as lattice regrowth, altough still imperfect, has been observed to occur at a temperature as low as 500 °C.
  • Nuclear Instruments and Methods in Physics Research B 120 (1996) 177-180

Publ.-Id: 567 - Permalink


Proximity gettering of copper in separation-by-implanted-oxygen structures
Yankov, R. A.; Hatzopoulos, N.; Skorupa, W.; Danilin, A.;
  • Lecture (Conference)
    E-MRS, Spring Meeting, Strasbourg, France, 4-7 June 1996
  • Nuclear Instruments and Methods in Physics Research B 120 (1996) 60

Publ.-Id: 566 - Permalink


A study of the blue photoluminescence emission from thermally-grown, Si+ -implanted SiO2 films after short-time annealing
Skorupa, W.; Yankov, R. A.; Rebohle, L.; Fröb, H.; Böhme, T.; Leo, K.; Tyschenko, I. E.; Kachurin, G. A.;
Thermal SiO2 films have been implanted with Si+ ions using double-energy implants (200 + 100 keV) at a substrate temperature of about -20 °C to total doses in the range 1.6 x 1016 - 1.6 x 1017 cm-2 followed by short-time thermal processing, in order to form a Si nanostructure capable of yielding blue photoluminescence (PL). The intensity and the peak position of the PL band have been investigated as a function of ion dose, manner of heat treatment, anneal time and anneal temperature. For the formation
of blue PL emitting centres, optimum processing conditions in terms of excess Si concentration and overall thermal budget are mandatory. The nature of the observed blue emission is discussed.
  • Lecture (Conference)
    E-MRS, Spring Meeting, Strasbourg, France, June 4-7, 1996
  • Nuclear Instruments and Methods in Physics Research B 120 (1996)106

Publ.-Id: 565 - Permalink


Damage behaviour and annealing of germanium implanted 6H-SiC
Pacaud, Y.; Heera, V.; Yankov, R. A.; Kögler, R.; Brauer, G.; Voelskow, M.; Skorupa, W.; Stoemenos, J.; Perez-Rodriguez, A.; Calro-Barrio, L.; Serre, C.; Morante, J.; Barklie, R.; Collins, M.; Holm, B.;
The present paper reports a study of the defect reduction
and recrystallization during annealing of Ge+-implanted 6H-SiC. Implants
have been performed at 200 keV with doses of 1x1014 and 1x1015 cm-2. Furnace
annealing has been carried out at temperatures of 500°, 900° and
1500 °C. Several analytical techniques including Rutherford backscattering
spectrometry in conjunction with channeling (RBS/C), cross-sectional transmission
electron microscopy (XTEM), positron annihilation spectroscopy (PAS), Raman
scattering (RS), and electron paramagnetic resonance (EPR) measurements
have been employed for sample characterization. It has been shown that
damage removal is more complicated than in ion-implanted Si. Using PAS
deeply diffusion vacancy-like defects were found far below the region defined
by TRIM as containing the maximum amount of nuclear energy deposition.
The amorphized SiC is characterized by carbon dangling bonds as revealed
by EPR. The recrystallization of amorphized SiC layers has been found to
be unsatisfactory for temperatures up to 1500 °C. The use of ion-beam-induced
epitaxial crystallization (IBIEC) has been more successful as lattice regrowth,
altough still imperfect, has been observed to occur at a temperature
as low as 500 °C.
  • Contribution to external collection
    IIT '96, Austin, Texas, USA; Proc. 11th Int. Conf. Ion Implantation Technology; The Inst. of Electrical and Electronics Eng., Piscataway, USA, 1997, p. 713

Publ.-Id: 564 - Permalink


Proximity gettering of Fe in SIMOX structures
Skorupa, W.; Yankov, R. A.; Hatzopoulos, N.; Danilin, A.;
  • Contribution to external collection
    IIT '96, Austin, Texas, USA; Proc. 11th Int. Conf. Ion Implantation Technology; The Inst. of Electrical and Electronics Eng., Piscataway, USA, 1997, p. 737

Publ.-Id: 563 - Permalink


Ion Beam Synthesis of SiC in Silicon-on-Insulator
Kögler, R.; Reuther, H.; Voelskow, M.; Skorupa, W.; Romano-Rodriguez, A.; Perez-Rodriguez, A.; Serre, C.; Calvo-Barrio, L.; Morante, J. R.;
Ion beam synthesis of ß-SiC in the top-Si-layer of a SIMOX (Separation by Implantation of OXygen) substrate is reported.
All the implanted C is captured inside the 200 nm top-Si-layer and is accumulated preferentially at the Si/SiO2-interface during annealing. A Si/SiC/SiO2-structure is obtained by C implantation at high temperature (T>500 °C) and subsequent annealing treatment (T=1250 °C). It consists of a crystalline Si overlayer, a Si layer with a high density of perfectly aligned ß-SiC grains and a buried oxide layer. Implantation at elevated temperatures is crucial for the quality of the SiC layer. However, the use of such implantation temperatures is limited by the dissolution of the buried oxide layer.
  • Contribution to external collection
    IIT '96, Austin, Texas, USA; Proc. 11th Int. Conf. Ion Implantation Technology; The Inst. of Electrical and Electronics Eng., Piscataway, USA, 1997, p. 709

Publ.-Id: 562 - Permalink


Impurity gettering in damaged regions of Si produced by high energy ion implantation
Kögler, R.; Panknin, D.; Skorupa, W.; Werner, P.; Danilin, A.;
Point defects and defect agglomerates are created by high
energy ion implantation into Si and subsequent annealing. These defects
are investigated by gettering of metal atoms and analysing the metal concentration
distribution. Beside a gettering layer at the projected ion range (Rp)
where the implant is deposited also a gettering layer is also found at
the Rp/2-position. This Rp/2-layer is related to implantation defects -
not to the implant atoms. It is thermally stable up to a temperature of
more than 1000 °C.
  • Contribution to external collection
    IIT '96, Austin, Texas, USA. 11th Int. Conf. Ion Implantation Technology; The Inst. of Electrical and Electronics Engineers, Piscataway, USA, 1997, p. 679

Publ.-Id: 561 - Permalink


Laser and X-ray spectroscopic studies of uranium-calcite interface phenomena
Geipel, G.; Reich, T.; Brendler, V.; Bernhard, G.; Nitsche, H.;
  • Lecture (Conference)
    Workshop JAERT, Japan
  • Journal of Nuclear Materials 248 (1997) 408-411

Publ.-Id: 560 - Permalink


Investigation of the Development of Irradiation - Induced Precipitates in VVER-440-Type Reactor Pressure Vessel Steels and Weld Metals During Irradiation and Annealing
Große, M.; Nitzsche, P.; Böhmert, J.; Brauer, G.;
The development of irradiation-induced precipitates in VVER-440 type reactor pressure vessel steels 15Kh2MFA and weld metals SV-10KhMFT during irradiation and post-irradiation annealing is studied by small angle neutron and X-ray scattering. The kinetic conditions for the precipitation of particles, which already exist in the unirradiated state, seem to be improved at temperatures of about 270 °C due to the irradiation. The size distribution of the irradiation-induced precipitates depends on the copper content and differs between weld and base metal. A strong correlation between the formation of irradiation-induced precipitates and the irradiation hardening is found. The hardness nearly linearly depends on the number of these precipitates.
  • Lecture (Conference)
    18th International Symposium "Effects of Radiation in Materials", Hyannis (USA), June 25 - 27, 1996, ASTM STP 1325

Publ.-Id: 559 - Permalink


Interpretation and Quality of the Tilted Axis Cranking Approximation
Frauendorf, S.; Meng, J.;
Comparing with the exact solutions of the model system of one and two particles coupled to an axial rotor, the quality of the semi classical tilted axis cranking approximation is investigated. Extensive comparisons of the energies and M1 and E2 transition probabilities are carried out for the lowest bands. Very good agreement is found, except near band crossings. Various recipes to take into account finite K within the frame of the usual principal axis cranking are included into the comparison. A set of rules is suggested that permits to construct the excited bands from the cranking configurations, avoiding spurious states.
  • Zeitschrift für Physik A 356 (3): 263-279 DEC 1996
  • Open Access LogoForschungszentrum Rossendorf; FZR-140 Preprint

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Publ.-Id: 558 - Permalink


Implantation and growth of large ß-FeSi2 precipitates and a-FeSi2 network structures in silicon
Reuther, H.; Dobler, M.;
Iron implanted and subsequently annealed n-type Si(111) was
studied by conversion electron Mössbauer spectroscopy and Auger electron
spectroskopy. Phase analysis performed with Mössbauer spectroscopy indicates
the formation of a mixture of ß- and a-FeSi2 due to the implantation
(200 keV, 3 x 1017 cm-2, 350 °C) and a complete transition of the mixture
to the ß-and the a-phase after annealing at 900 °C for 18 h and
1150 °C for 1 h, respectively. The iron concentration profiles were
determined with Auger electron sputter depth profiling. The profile of the
as-implanted sample is Gaussian shaped and boradened after annealing at 900
°C to a pleateau-like profile. For the sample annealed at 1150 °C
only a slight broadening occurs and depth depending fluctuations of the iron
concentration can be observed. Investigations with scanning Auger electron
spectroscopy show in the case of the as-implanted sample only slight fluctuations
of the iron distribution in the center of the profile. After annealing at
900 °C large separated ß-FeSi2 precipitates grow due to the process
of Ostwald ripening. At 1150 °C Ostwald ripening and coalescence of
the precipitates occur and a wide extended penetration a-FeSi2 network structure
is formed. It is the first time that such large iron disilicide structures
could be proved by scanning Auger electron spectroscopy.
  • Applied Physics Letters 69 (1996) 3176 - 3178

Publ.-Id: 557 - Permalink


Tritium Depth Profiling in Carbon by Accelerator Mass Spectrometry
Friedrich, M.; Sun, G.; Grötzschel, R.; Behrisch, R.; Garcia-Rosales, C.; Roberts, M. L.;
  • Nuclear Instruments and Methods in Physics Research B 123 (1997) pp. 410-413

Publ.-Id: 556 - Permalink


Ion Beam Processing of SiC
Skorupa, W.; Heera, V.; Pacaud, Y.; Weishart, H.;
A short review is presented concerning problems of ion beam processing of single crystalline silicon carbide. Emphasis is given
to recent results on point defect, extended defects, amorphization and recrystallization, electrical activation of dopant atoms, and metallization.
  • Nuclear Instruments and Methods in Physics Research B 120 (1996) 114-120

Publ.-Id: 553 - Permalink


Speciation of Uranium in Natural Waters of an Uranium Mining Area
Geipel, G.; Bernhard, G.; Brendler, V.; Brachmann, A.; Nitsche, H.;
  • Lecture (Conference)
    NRC 4, St. Malo, Sept. 1996

Publ.-Id: 551 - Permalink


Investigation of the ion acoustic effect during focused ion beam irradiation
Teichert, J.; Bischoff, L.; Köhler, B.;
  • Lecture (Conference)
    E-MRS, Strasbourg, 4.-7.6.1996

Publ.-Id: 550 - Permalink


The use of plasma source ion implantation for wear protection
Günzel, R.; Brutscher, J.; Mändl, S.; Möller, W.;
Plasma source ion implantation (PSII) has been developed
as an alternative technique to circumvent the limitations of conventional
ion implantation, like the requirements of a complicated target handling
and beam raster system for a uniform ion implantation of 3-dimensional
samples. In this method, a plasma sheath conformably surrounds the target.
By applying negative high voltage pulses, positively charged ions are accelerated
from the plasma trough the sheath and implanted into the target. Critical
parameters for the further development of this implantation process are
the ion implantation current and the sheath expansion characteristics.
  • Lecture (Conference)
    NATO-ARW, Portimao, Portugal, 30.5.-5.6.1996
  • Book (Authorship)
    Y. Pauleau and P. B. Barna (eds), Protective Coatings and Thin Films, pp. 635-647, c 1997 Kluwer Academic Publishers, Printed in the Netherlands

Publ.-Id: 547 - Permalink


Consideration of Added Stiffness Resulting from Edging Out of an Axial Annular Flow by Motions of the Pressure Vessel and the Core Barrel
Zoller, J.; Altstadt, E.; Grunwald, G.; Zimmermann, W.;
  • Lecture (Conference)
    IMORN '26, Piestany, May 27 - 29, 1996

Publ.-Id: 546 - Permalink


Charge pickup of 238U at relativistic energies
Seidel, W.; Möhlenkamp, T.; Rubehn, T.; u. a.; Bassini, R.; u. a.; Blaich, T.; Immé, G.; u. a.; Moretto, L. G.; Schüttauf, A.; Trzcinski, A.; u. a.;
  • Physical Review C 53 (1996) pp. 993-996

Publ.-Id: 543 - Permalink


Theoretical study of boron nitride modifications at hydrostatic pressures
Albe, K.;
This paper presents a detailed study of boron nitrides
at hydrostatic pressures. Cohesive properties of zincblende (c-BN), wurtzite
(w-BN), hexagonal (h-BN), rhombohedral (r-BN) and rocksalt structure are
calculated by systematic optimization of unit cell parameters using total-energy
DFT techniques. With focus on the very rarely discussed layered modifications
the p - V equation of states are derived. It is confirmed taht the isothermal
bulk modulus of the sp2 bonded phases is more than ten times smaller in
comparison to the dense phases. Additionally the equilibrium line of c-BN
and h-BN in the phase p, T diagram is estimated. According to recent experimental
reports c-BN is predicted as stable modification at standard conditions.
  • Physical Review B 55 (1997) 10 pp. 6203-6210

Publ.-Id: 542 - Permalink


Aufnahme und Verteilung von Trichloressigsäure in Trieben Norwegischer Fichte
Uhlirova, H.; Matucha, M.; Kretzschmar, M.; Bubner, M.;
  • Umweltwissenschaften und Schadstoff-Forschung: Zeitschrift für Umweltchemie und Ökotoxikologie 8 (1996) 3 pp. 138-142

Publ.-Id: 541 - Permalink


Decay rates of resonance states at high level density
Persson, E.; Gorin, T.; Rotter, I.;
Abstract
The time dependent Schrödinger equation of an open quantum mechanical system is solved by using the stationary bi-orthogonal eigenfunctions of the non-Hermitean time independent Hamilton operator. We calculate the decay rates at low and high level density in two different formalism. The rates are, generally, time dependent and oscillate around an average value due to the non-orthogonality of the wavefunctions. The decay law is studied disregarding the oscillations. In the one-channel case, it is proportional to t-b with b ≈ 3/2 in all cases considered, including the critical region of overlapping where the non-orthogonality of the wavefunctions is large. Starting from the shell model, we get b ≈ 2 for 2 and 4 Open decay channels and all coupling strengths to the continuum. When the closed system is described by a random matrix, b ≈ 1 + K/2 for K = 2 and 4 channels. This law holds in a limited time interval. The distribution of the widths is different in the two models when more than one channel are open. This leads to the different exponents b in the power law. Our calculations are performed with 190 and 130 states, respectively, most of them in the critical region. The theoretical results should be proven experimentally by measuring the time behaviour of de-excitation of a realistic quantum system.
  • Open Access LogoForschungszentrum Rossendorf; FZR-139 Preprint
  • Physical Review E 54 (1996) 4, pp. 3339-51

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Publ.-Id: 540 - Permalink


Saxon Wind Energy Ressources: Comparison of WASP and KAMM Results
Hirsch, W.; Rindelhardt, U.; Tetzlaff, G.;
The wind energy ressources of a selected saxon area ( 64 km x 48 km ) has been investigated in detail. The region can be characterized by a mean height of 200 m a.s.l. with complex surface profil. Based on measuring data of three stations WASP calculations with a grid step of 0.25 km has been performed for the whole region. The data are compared with calculation results of the mesoscale KAMM model. These calculations based on the geostrophic wind data of the Czech station Prague and used a 1.0 km and a 2.5 km grid ( coresponding 60 and 120 wind clusters ). The ressource maps ( mean wind velocity and power density ) calculated by both methods show corresponding high wind potential in the investigated area. Differences in the absolute values are explained by the features of the used programmes.
  • Lecture (Conference)
    Proceedings of the 1996 European Union Wind Energy Conference and Exhibition, Göteborg (Sweden), 20.-24.5.1996, pp. 604-607

Publ.-Id: 539 - Permalink


Solare Warmwasserbereitung und Fernwärmeeinspeisung -Waldblickschule Freital-
Brünig, D.; Rindelhardt, U.;
In ein mit Erdgas betriebenes konventionelles Fernwärmesystem (Anschlußleistung 2,1 MW) wurde eine Solarkollektoranlage mit einer Bruttofläche von 100 m² integriert. Die Kollektoranlage diente vorrangig der Erzeugung von Brauchwarmwasser für eine Schule, solare Überschüsse wurden in den Rücklauf des Fernwärmesystems eingespeist. Ein umfangreiches Meßprogramm ermöglichte Effizienzuntersuchungen des Systems.
Der jährliche Nettoertrag des Solarsystems lag bei 280 kWh/m² bei einem Systemnutzungsgrad von 26%. Beide Kennziffern wurden durch hohe Rücklauftemperaturen (58°C) im Nahwärmenetz negativ beeinflußt. Weitere Untersuchungen galten dem Betrieb der eingesetzten Schichtspeicher (Reihenschaltung). Bei Ausschöpfung der in dem Vorhaben deutlich gewordenen Optimierungspotentiale können in künftigen Anlagen Nettoerträge von 350 kWh/m² und solare Wärmegestehungskosten unter 30 Pf./kWh erreicht werden.
  • Open Access LogoForschungszentrum Rossendorf; FZR-137, April 1996

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Publ.-Id: 537 - Permalink


Electromagnetic signals from deconfined matter resulting from ultrarelativistic heavy-ion collisions
Kämpfer, B.; Peshier, A.; Hentschel, M.; Soff, G.; Pavlenko, O. P.;
  • Contribution to external collection
    World Scientific, Singapore: Structure of Vacuum and Elementary Matter, World Scientific 1997, New Jersy, London, Hongkong, (Eds.) H. Stoecker, A. Gallmann, J. H. Hamilton, p. 483
  • Open Access LogoForschungszentrum Rossendorf; FZR-136

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Publ.-Id: 536 - Permalink


Elektroenergieerzeugung einer kombinierten Wind-Photovoltaik-Anlage in Ottendorf-Okrilla (Sachsen)
Futterschneider, H.; Hirsch, W.; Rindelhardt, U.; Teichmann, G.;
Vom Zentrallager der Plus-Warenhandelsgesellschaft in Ottendorf-Okrilla (Sachsen) wird seit 1992 eine hybride Wind-Photovoltaik-Anlage zur Erzeugung von Elektroenergie betrieben. Die Anlage besteht aus einer 60-kW-Windkraftanlage des Typs TW 60 und einer Phtovoltaikanlage mit einer Spitzenleistung von 3,18 kW. Letztere zeichnet sich durch einige Besonderheiten (Orientierung des Generators, Master-Slave-Betieb der Wechselrichter) aus. Das Betriebsverhalten der Anlagen wurde über einen längeren Zeitraum untersucht.

Im Jahr 1995 erreichte die Photovoltaikanlage mit 689 Vollastbetriebsstunden etwa die Ergebnisse anderer Photovoltaikanlagen in Sachsen. Mögliche höhere Erträge werden durch die gewählte Orientierung des Generators verhindert. Die Master-Slave-Schaltung der Wechselrichter arbeitete ohne Probleme. Ihre Effektivität wurde durch die nicht optimale Abstimmung von Generator- und Wechselrichterleistung beeinträchtigt.
  • Open Access LogoForschungszentrum Rossendorf; FZR-138 April 1996

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Publ.-Id: 535 - Permalink


A Neural-Network Approach for Acoustic Leak Monitoring in Pressurized Plants with Complicated Topologies
Hessel, G.; Schmitt, W.; Weiß, F.-P.;
A neural-network approach has been developed for localizing leakages and estimating the leak rate in pressurized plants with complicated three-dimensional structures. Results are presented from experiments with simulated leaks at a VVER-440 reactor vessel head. As features for characterizing the occurrence and the location of a leak, RMS values of acoustic emission sensors and coherence values and power spectra of microphone signals were used. Three-layer perceptron networks were found to be best suited for leak localization and for estimation of leak rates. However, the estimation of leak rates required an additional neural network because a different normalization procedure was necessary for extracting features from the RMS values of the acoustic emission sensors. Perceptron networks with continuously valued outputs corresponding to the coordinates of the leak positions were useful for classifying even positions which had not been offered during training.
  • Control Engineering Practice, Vol. 4, No. 9, pp. 1271-1276, 1996, pp. 1271 - 1276

Publ.-Id: 534 - Permalink


Institute of Nuclear and Hadron Physics; Annual Report 1995
Dönau, F.; Prade, H.; Enghardt, W.; Möller, K.; Mösner, J.; Winter, G.; Wünsch, R.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-130

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Publ.-Id: 533 - Permalink


Institute of Ion Beam Physics and Materials Research; Annual Report 1995
Möller, W.; Wieser, E.; von Borany, J.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-129

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Publ.-Id: 532 - Permalink


Lieferung von Investitionsgütern zur Erhöhung der Betriebssicherheit des Kernkraftwerkes Saporoshje - Betriebliche Überwachung, 2. Realisierungsstufe -
Beyer, M.; Carl, H.; Schikora, B.; Schumann, P.; Seidel, A.; Zschau, J.;
Im Rahmen eines Programms des Bundesministeriums für Umwelt, Naturschutz und Reaktorsicherheit zur Zusammenarbeit mit den MOE-Staaten und der GUS auf dem Gebiet der kerntechnischen Sicherheit hat das Forschungszentrum Rossendorf, Institut für Sicherheitsforschung, im Verbund mit dem technischen Überwachungsverein TÜV Rheinland, Institut für Kerntechnik und Strahlenschutz, die einvernehmlich spezifizierten "technischen Mittel für ein System zur verbesserten betrieblichen Überwachung" an das Kernkraftwerk Saporoshje, Ukraine, geliefert und in Betrieb genommen. Im vorliegenden Bericht (Textteil) werden die Lieferungen und Leistungen nach Art und Umfang (Beschaffenheit, Abnahmeprüfung, Übergabe und Inbetriebnahme der technischen Mittel und die für das ukrainische Fachpersonal durchgeführten Schulungsmaßnahmen) bis zur Aufnahme des Probebetriebes am 30. November 1995 beschrieben. Dem Bericht ist ein Anhang A mit Vorschlägen zur Gestaltung der automatisch arbeitenden Überwachungssoftware und ein Anhang B mit wissenschaftsorganisatorischen Details beigefügt.
  • Open Access LogoForschungszentrum Rossendorf; FZR-135 April 1996

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Publ.-Id: 531 - Permalink


The binary decay of hot heavy nuclei: fission, evaporation, and also flow?
Wagner, W.; Ortlepp, H.-G.; Gippner, P.; Herbach, C.-M.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-133 Preprint

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Publ.-Id: 530 - Permalink


Bethe-Salpeter amplitudes and static properties of the deuteron
Kaptari, L. P.; Umnikov, A. Y.; Bondarenko, S. G.; Kazakov, K. Y.; Khanna, F. C.; Kämpfer, B.;
Abstract
Extended calculations of the deuteron's static properties, based on the numerical solution of the Bethe-Salpeter equation,.are presented. A formalism is developed, which provides a comparative analysis of the covariant amplitudes in various representations and nonrelativistic wave functions. The magnetic and quadrupole moments of the deuteron are calculated in the Bethe-Salpeter formalism and tlie role of relativistic corrections is discussed.
  • Physical Review C 54 (1996) 3 pp. 986-1005
  • Open Access LogoForschungszentrum Rossendorf; FZR-134 Preprint

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Publ.-Id: 529 - Permalink


Unexpected formation of the new oxorhenium (V) complex [ReO(NH(CH2CH2S)2)(SC6H5)] obtained by N-C cleavage of the tripodal ligand N(CH2CH2SH)3
Glaser, M.; Spies, H.; Berger, R.; Hahn, F. E.; Lügger, T.; Johannsen, B.;
  • Inorganica Chimica Acta 257 (1997) 143-147

Publ.-Id: 528 - Permalink


Inertial Mass of the Chiral Quark-Loop Soliton in the Nambu & Jona-Lasinio Model at Finite Temperature and Density
Schleif, M.; Wünsch, R.;
Abstract
We consider the mass of the one-loop hedgehog soliton of the bosonized SU(2) Nambu & Jona-Lasinio model embedded in hot nuclear matter mimiced by a gas of constituent quarks. We prove that the proper-time regularized and self-consistently determined soliton in a heat bath obeys Poincare's invariance up order V2. At ifinite temperature and chemical potential, we show that the inertial mass obtained in the perturbative pushing approach coincides with the total internal energy of the soliton.
  • Open Access LogoForschungszentrum Rossendorf; FZR-132 Preprint

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Publ.-Id: 527 - Permalink


Output Maximization of a 7.25 GHz ECR Ion Source
Henke, D.; Tyrroff, H.; Wirth, H.; Zschornack, G.;
  • Open Access LogoForschungszentrum Rossendorf; FZR-131 Preprint

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Publ.-Id: 526 - Permalink


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