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We develop a method of finding analytical sotutions of the Bogolyubov-de Gennes equations for the excitations of a Bose condensate in the Thomas-Fermi regime in harmonic traps of any asymmetry and introduce a classification of eigenstates. In the case of cylindrical symmetry we emphasize the presence of an accidental degeneracy in the excitation spectrum at certain values of the projection of orbital angular momentum on the symmetry axis and discuss possible consequences of the degeneracy in the context of new signatures of Bose- Einstein condensation
Two-dimensional bouyancy-driven convection in a horizontal fluid layer with stress-free boundary conditions at top and bottom and periodic boundary conditions in the horizontal direction is investigated by means of numerical simulation and bifurcation-analysis techniques. As the bouyancy forces increase, the primary stationary and symmetric convection rolls undergo successive Hopf bifurcations, bifurcations to traveling waves, and phase lockings. We pay attention to symmetry breaking and its connection with the generation of large-scale horizontal flows. Calculations of Lyapunov exponents indicate that at a Rayleigh number of 2.3×105 no temporal chaos is reached yet, but the system moves nonchaotically on a 4-torus in phase space.
Energieumsetzende Systeme: Nutzung von regenerativen Energieformen am Beispiel der Windenergie
(1997)
Control of noise-induced oscillations of a pendulum with a rondomly vibrating suspension axis
(1997)
The pendant drop technique was used to determine p/A isotherms of docosanic acid spread on the drop surface of an aqueous polymer solution. Two water soluble polymers were used, poly(dimethyl-diallyl-ammoniumchloride) and sodium poly(styrene sulfonate-b-ethylethylene). By fast changes of the drop volume, the monolayers were compressed and dilated. The stress relaxation was monitored and surface rheological dilation parameters were obtained. It is shown that the fatty acid monolayer can be mechanically stabilized by both interacting anionic and cationic polymers. In the case of the anionic polymer, the interaction becomes more pronounced in the presence of salts in the subphase (counterions). Brewster angle microscopy shows that the typical tilt-orientation of crystalline domains of the fatty acid monolayers transforms into a more uniform and fluid-like structure caused by the polymer/monolayer interaction. The surface rheological behavior is dramatically influenced by the polymer binding. The interaction results in surface dilational viscoelastic properties and show that there is a strong resistance against expansion of the complex fatty acid/polymer layer.
Germany gained its unity, but the restoration of virtual national cohesion presents itself as a lasting problem. The rebuilding of common national identity forms one complex aspect. Particular West and East German political, social and cultural features still exist. The East Germans brought elements of a peculiar identity into the unity; as a repercussion of some setbacks in their position and of some actual inter-German distinctions, their peculiarities are not yet in retreat. They prolong their role as conventional feelings, in temporary behaviours as an answer to their actual stance, and to a certain extent also with traits staged and suggested by entrenched media interpretations about the presently hampered inter-German evolution.
The dynamics of noisy bistable systems is analyzed by means of Lyapunov exponents and measures of complexity. We consider both the classical Kramers problem with additive white noise and the case when the barrier fluctuates due to additional external colored noise. In case of additive noise we calculate the Lyapunov exponents and all measures of complexity analytically as functions of the noise intensity resp. the mean escape time. For the problem of fluctuating barrier the usual description of the dynamics with the mean escape time is not sufficient. The application of the concept of measures of complexity allows to describe the structures of motion in more detail. Most complexity measures sign the value of correlation time at which the phenomenon of resonant activation occurs with an extremum.
We analyse occupation number fluctuations of an ideal Bose gas in a trap which is isolated from theenvironment with respect to particle exchange (canonical ensemble). We show that in contrast to the predictions of thegrand- canonical ensemble, the counting statistics of particles in the trap ground state changes from monotonously decreasing above the condensation temperature to single-peaked below that temperature. For the exactly solvable case of a harmonic oscillator trapping potential in one spatial dimension we extract a Landau-Ginzburg functional which - despite the non- interacting nature of the system - displays the characteristic behaviour of a weakly interacting Bose gas. We also compare our findings with the usual treatment which is base on the grand-canonical ensemble. We show that for an ideal Bose gas neither are the grand-canonical and canonical ensemble thermodynamically equivalent, nor the grand-canonical ensemble can be viewed as a small system in diffusive contact with a particle reservoir.
Sport und Physik
(1997)
Electrochemical polymerization of functionalized thiohene derivatives for immobilization of proteins
(1997)
Die Rolle des Staats in der sozialen Marktwirtschaft bei Globalisierung der Wirtschaftsbeziehungen
(1997)
Eu-Osteuropa
(1997)
Das Buch enthält eingangs eine Einführung in den Menschenrechtsschutz auf der europäischen Ebene, die die erschiedenen Institutionen, Garantieen und Überwachungsmechanismen vorstellt. Der zweite Beitrag beschreibt die historische Entwicklung des Minder-heitenschutzes und seine heutige Ausformung. Im dritten Beitrag wird der Schutz vor Folter auf internationaler und europäischer Ebene behandelt und auf Fragen eingegangen, die sich in diesem Zusammenhang für die Bundesrepublik Deutschland stellen. Der vierte Abschnitt erörtert die sprachenrechtliche Situation von Minderheiten, wobei besonderes Augenmerk auf die Rechtsentwicklung in Europa gelegt wird. Im letzten Beitrag diskutiert der Autor den Zusammenhang von Rassismus und Menschenrechten.
Tagungsbericht: Weiß, Norman: Der Europäische Gerichtshof für Menschenrechte - Organisation und Verfahren - Fragen der Umsetzung des Protokolls Nr. 11 zur Europäischen Menschenrechtskonvention (EMRK) <1997, Potsdam> / 4. wiss. Tagung des Menschenrechtszentrums der Universität Potsdam, Generalsekretariat des Europarates am 19., 20. September 1997
Inhaltsübersicht I. Einführung in die Grundlagen der Europäischen Menschenrechtskonvention 1. Entstehung und Ziele der Konvention 2. Überblick über die materiellen Inhalte der Konvention 3. Organe der Konvention 4. Entscheidungen II. Das Individualrechtsschutzverfahren nach geltendem Recht 1. Überblick 2. Verfahren vor der Kommission I (Zulässigkeit) 3. Vorläufige Maßnahmen 4. Verfahren vor der Kommission II (Meritorisches Verfahren) 5. Verfahren vor dem Gerichtshof (Begründetheit) 6. Entscheidung des Ministerkomitees 7. Kontrollverfahren 8. Entscheidungswirkung III. Das Indivudualbeschwerdeverfahren nach künftigem Recht IV. Bewertung V. Prüfungsschema VI. English summary
Einführung in den Individualrechtsschutz nach der Anti-Folter-Konvention der Vereinten Nationen
(1997)
This article gives a short introduction in the United Nations Convention against Torture and other Cruel, Inhuman or Degrading Treatment or Punishment. Focussing on the individual communications, it describes the admissibility conditions and the procedure before the Committee.
In diesem ersten Bericht wird über den Problemkreis Kinder- und Jugendkriminalität gehandelt. Damit soll versucht werden, neue Argumentationsansätze in die aktuelle Diskussion über die allgemeine Verbrechensbekämpfung („Erfolgsmodell New York"1) und die spezielle Behandlung von Heranwachsenden2 einzubringen.
Inhaltsübersicht I. Vereinte Nationen II. Rechtsbeistand im nationalen Vergleich III. Strafjustiz gegenüber Kindern IV. Erstbericht der Bundesrepublik Deutschland zur Kinderrechtskonvention
Der Beitrag beschreibt die geschichtliche Entwicklung des Menschenrechtsschutzes auf der europäischen Ebene und konzentriert sich dann auf seine derzeitige Ausgestaltung. Im Mittelpunkt der Darstellung stehen die im Rahmen des Europarates erarbeiteten menschenrechtlichen Garantien, hier insbesondere die Europäische Menschenrechtskonvention. Der im Rahmen der KSZE/OSZE vermittelte Menschenrechtsschutz wird ebenso be-handelt wie der Bereich der Europäischen Gemeinschaft / Europäischen Union.
Der Aufsatz behandelt die völkerrechtlichen Grundlagen des Folterverbotes sowohl auf internationaler als auch auf regionaler Ebene und erläutert die Möglichkeiten der völkerrechtlichen Überwachungen. Besonderes Gewicht liegt hierbei naturgemäß auf der Arbeit des Ausschusses gegen die Folter und andere grausame, unmenschliche oder erniedrigende Behandlung oder Strafe.
Der Beitrag zeichnet die völkerrechtlichen Normierungen des Verbotes der Todesstrafe nach und erläutert, welche Beschränkungen der staatlichen Souveränität im Bereich der Todesstrafe auferlegt sind. Als Ergebnis kann festgestellt werden, daß es kein generelles, jeden Staat bindendes Verbot der Todesstrafe gibt. Noch ist es so, daß ein Staat sich direkt und ausdrücklich zur Abschaffung der Todesstrafe bekennen muß solange er dies nicht tut, ist die Verhängung und Vollstreckung der Todesstrafe bei Beachtung bestimmter rechtsstaatlicher Kautelen völkerrechtlich gesehen zulässig.
We discuss the exact particle number counting statistics of degenerate ideal Bose gases in the microcanonical, canonical, and grand-canonical ensemble, respectively, for various trapping potentials. We then invoke the Maxwell's Demon ensemble [P. Navez et al., Phys. Rev. Lett.(1997)] and show that for large total number of particles the root-mean-square fluctuation of the condensate occupation scales delta n0 proportional to [T/Tc]r Ns with scaling exponents r=3/2, s=1/2 for the 3D harmonic oscillator trapping potential, and r=1, s=2/3 for the 3D box. We derive an explicit expression for r and s in terms of spatial dimension D and spectral index sigma of the single- particle energy spectrum. Our predictions also apply to systems where Bose-Einstein condensation does not occur. We point out that the condensate fluctuations in the microcanonical and canonical ensemble respect the principle of thermodynamic equivalence.
In modern political philosophy social contract theory is the most prominent approach to individual rights and fair institutions. According to social contract theory the system of rights in a society ought to be justified by reconstructing its basic features as a contract between the mutually unconcerned members of society. This paper explores whether social contract theory can successfully be applied to justify rights of future generations. Three competing views are analysed: Rawls's theory of justice, Hobbes's radical liberalism and Gauthier's bargaining framework based on the Lockean proviso.
The paper is an enquiry into dynamic social contract theory. The social contract defines the rules of resource use. An intergenerational social contract in an economy with a single exhaustible resource is examined within a framework of an overlapping generations model. It is assumed that new generations do not accept the old social contract, and access to resources will be renegotiated between any incumbent generation and their successors. It turns out that later generations will be in an unfortunate position regardless of their bargaining power.
This paper opens a series of discussion papers which report about the findings of a research project within the Phare-ACE Programme of the European Union. We, a group of Bulgarian, German, Greek, Polish and Scottish economists and agricultural economists, undertake this research to provide An Integrated Analysis of Industrial Policies and Social Security Systems in Countries in Transition.1 This paper outlines the basic motivation for such study.
Beziehungen zwischen Texturen und Molekülpackung in Monoschichten an der Luft/Wasser-Grenzfläche
(1997)
Biosensors for food analysis
(1997)
Weak gravitational lensing by large-scale structure affects the determination of the cosmological deceleration parameter q0. We find that the lensing induced dispersions on truly standard candles are 0.04 and 0.02 mag at redshift z = 1 and z = 0.5, respectively, in a COBE-normalized cold dark matter universe with Omega 0 = 0.40, Lamda 0 = 0.6, H = 65 km s-1 Mpc-1, and sigma 8 = 0.79. It is shown that one would observe q0 = -0.395^{+0.125}_{-0.095} and q0 = - 0.398^{+0.048}_{-0.077} (the error bars are 2 sigma limits) with standard candles with zero intrinsic dispersion at redshift z = 1 and z = 0.5, respectively, compared to the truth of q0 = -0.400. A standard COBE normalized Omega 0 = 1 CDM model would produce three times as much variance and a mixed (hot and cold) dark matter model would lead to an intermediate result. One unique signature of this dispersion effect is its non-Gaussianity. Although the lensing induced dispersion at lower redshift is still significantly smaller than the currently best observed (total) dispersion of 0.12 mag in a sample of type Ia supernovae, selected with the multicolor light curve shape method, it becomes significant at higher redshift. We show that there is an optimal redshift, in the range z ~ 0.5--2.0 depending on the amplitude of the intrinsic dispersion of the standard candles, at which q0 can be most accurately determined.