TY - INPR A1 - Reiss, Harald T1 - Time scales and existence of time holes in non-transparent media N2 - The analysis presented in this paper applies to experimental situations where observers or objects to be studied, all at stationary positions, are located in environments the optical thickness of which is strongly different. Non-transparent media comprise thin metallic films, packed or fluidised beds, superconductors, the Earth’s crust, and even dark clouds and other cosmological objects. The analysis applies mapping functions that correlate physical events, e, in non-transparent media, with their images, f(e), tentatively located on standard physical time scale. The analysis demonstrates, however, that physical time, in its rigorous sense, does not exist under non-transparency conditions. A proof of this conclusion is attempted in three steps: i) the theorem “there is no time without space and events” is accepted, (ii) images f[e(s,t)] do not constitute a dense, uncountably infinite set, and (iii) sets of images that are not uncountably infinite do not create physical time but only time-like sequences. As a consequence, mapping f[e(s,t)] in non-transparent space does not create physical analogues to the mathematical structure of the ordered, dense half-set R+ of real numbers, and reverse mapping, f-1f[e(s,t)], the mathematical inverse problem, would not allow unique identification and reconstruction of original events from their images. In these cases, causality as well as invariance of physical processes under time reversal, might be violated. An interesting problem is whether temporal cloaking (a time hole) in a transparent medium, as very recently reported in the literature, can be explained by the present analysis. Existence of time holes could perhaps be possible, not in transparent but in non-transparent media, as follows from the sequence of images, f[e(s,t)], that is not uncountably infinite, in contrast to R+. Impacts are expected for understanding physical diffusion-like, radiative transfer processes and stability models to protect superconductors against quenchs. There might be impacts also in relativity, quantum mechanics, nuclear decay, or in systems close to their phase transitions. The analysis is not restricted to objects of laboratory dimensions. KW - Zeitrichtung KW - Strahlungstransport KW - Supraleiter KW - Nicht-Transparente Medien KW - Physikalische Zeit KW - Inverse Probleme KW - Time hole KW - mapping function KW - Monte Carlo simulation Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73554 N1 - Überarbeitung des Artikels urn:nbn:de:bvb:20-opus-67268 ER - TY - THES A1 - Reiss, Harald T1 - Strahlungstransport in dispersen nicht-transparenten Medien T1 - Radiative transfer in disperse non-transparent media N2 - In dieser Habilitationsschrift wird das Gesamtgebiet des Wärmetransports in dispersen Medien untersucht, kompakt, ohne Anspruch auf Vollständigkeit, jedoch mit Schwerpunkt auf Strahlungstransport in nicht-transparenten Medien; hier sind es bevorzugt hochporöse Substanzen, die aus Festkörperteilchen bestehen. Die Ergebnisse lassen sich auf andere disperse nicht-transparente Medien wie dichte Gasatmosphären oder einige Zweiphasengemische übertragen, wenn Nicht-Strahlungsanteile und Gesamt-Energieerhaltung korrekt formuliert werden. Die vorliegenden Untersuchungen konzentrieren sich auf stationäre Randbedingungen und Strahlungsquellen. Die Motivation zu dieser Arbeit ist mindestens zweifach: Die Trennung des totalen Wärmestroms in seine Komponenten, in irgendeinem kontinuierlichen oder dispersen Medium, ist eines der herausfordernden, gleichzeitig schwierigsten physikalischen Probleme bei der Analyse des Wärmetransports; zum zweiten ist es für die Verringerung von Wärmeverlusten (z. B. in thermischen Isolierungen) dringend erforderlich, die einzelnen Komponenten der Wärmeverlustströme zu kennen, um sie einzeln zu minimieren (das geht offensichtlich nur, wenn man den totalen Wärmstrom in seine Komponenten zerlegen kann). Die Trennung kann erfolgreich sein, wenn die optische Dicke des untersuchten Mediums sehr groß ist (das Medium ist dann nicht-transparent). In dieser idealen, in der Energietechnik jedoch häufig auftretenden Situation (und nicht nur dort), liefert das Strahlungsdiffusionsmodell den korrekten Ansatz zur Beschreibung des Strahlungsanteils und dessen Temperaturabhängigkeit. Wegen Energieerhaltung und mit der additiven Näherung erlaubt dieses Ergebnis umgekehrt die Berechnung auch der Nichtstrahlungsanteile im totalen Wärmestrom; diese sind demnach alle gleichzeitig in kalorimetrischen Messungen zugänglich. Damit wird nachfolgende separate Analyse dieser Komponenten mittels geeigneter theoretischer Modelle möglich. Da das Temperaturprofil im Medium alle Wärmestromkomponenten zum totalen Wärmestrom miteinander koppelt, ist für diesen Ansatz die Kenntnis der Temperaturabhängigkeit auch aller Nicht-Strahlungsanteile erforderlich. Neben der kalorimetrischen Methode kann die Bestimmung der Extinktion des dispersen Mediums und hiermit des Strahlungstransports auch mittels Spektroskopie sowie Berechnung nach der strengen Mie-Theorie der Lichtstreuung und mit dem Rosseland-Mittelwert vorgenommen werden. Dadurch wird ein Vergleich möglich zwischen Ergebnissen, die mittels drei voneinander völlig unabhängiger Methoden, nämlich kalorimetrisch, spektroskopisch und analytisch/numerisch erzielt wurden. Die Ergebnisse stimmen überein, wenn das Medium nicht-transparent ist; dieser Nachweis wird in der vorliegenden Habilitationsschrift geführt. Im ersten Teil der Habilitationsschrift wird in breit angelegtem Review die Fachliteratur zum Strahlungstransport bis zum Jahr 1985 diskutiert und Methoden zur Lösung der Strahlungstransportgleichung auch im Fall stark anisotroper Streuung beschrieben. Wegen der Forderung nach Energieerhaltung und mit dem oben genannten Ziel, auch die Nicht-Strahlungskomponenten zu analysieren, muß diese Diskussion die theoretischen Aspekte auch dieser Anteile (hier Gas- und Festkörperkontakt-Wärmetransport) einschließen. Den Schluß des ersten Teils bildet ein Katalog offener Fragen, die im zweiten Teil der Habilitationsschrift angegangen werden. Dort werden mittels experimenteller und analytisch/numerischer Ergebnisse das Strahlungsdiffusionsmodell und seine Anwendbarkeit auf disperse nicht-transparente Medien bestätigt. Die Analysen sind gerichtet auf reine oder mit Infrarot-Trübungsmitteln dotierte Pulver und Faserpapiere; beide sind leicht zugängliche, wohl-definierte Testsubstanzen disperser Medien. Ein wichtiger Teil dieser Untersuchungen enthält Messungen ihrer Wärmeleitfähigkeit unter Vakuum und unter externer mechanischer Druckbelastung. Mit evakuierten, druckbelasteten Faserpapieren wurden Wärmeleitfähigkeiten erzielt, die zu den niedrigsten gehören, die bis 1985 an solchen Medien bei hohen Temperaturen gemessen wurden. Weiter sollen optimale Teilchendurchmesser gefunden werden, mit denen das Extinktionsvermögen solcher Schüttungen signifikant erhöht werden kann. Insbesondere ist eine exotische Vorhersage der Mie-Theorie zu prüfen, nach welcher die Extinktion perfekt elektrisch leitender, langer, extrem dünner Zylinder (unter 50 nm) um Größenordnungen über derjenigen herkömmlicher (nichtleitender) Pulver oder Fasern liegt; hierfür sind Materialproben herzustellen. In der Habilitationsschrift wird aufgezeigt, welcher Weg für diesen Nachweis beschritten werden muß (wenige Jahre nach Vorlage der Habilitationsschrift wurden Gustav Mies und Milton Kerkers Vorhersagen auf diesem Weg mit feinsten metallisierten Glasfasern und mit Nickelfasern in Veröffentlichungen des Autors gemeinsam mit J. Fricke, M. Arduini-Schuster, H.-P. Ebert, R. Caps, D. Büttner und A. Kreh erstmalig bestätigt). N2 - The present thesis for habilitation investigates, in compact form, without claiming completeness, the field of heat, in particular radiative, transfer in disperse media if they are non-transparent. Preference is given to high porosity substances being composed of solid particles. The obtained results can be applied to other disperse media like dense gas atmospheres or some two-phase fluids provided non-radiative components of total heat flow, and corresponding total energy balances, are appropriately modelled. The present investigations are concentrated on stationary boundary conditions and radiation sources. Motivation for this work is at least two-fold: First, splitting of total heat flow into its components is one of the most challenging and difficult problems of experimental physics in any, continuous or disperse, medium, and, secondly, reduction of total heat losses (e. g. in thermal insulations) inevitably requests minimisation steps simultaneously to be taken with all its separated components (this of course works only if separation really is successful). Separation can be successful if the optical thickness of the medium is large (the medium then is non-transparent). In this ideal situation that, nonetheless, frequently arises, not only in energy technology, the radiative diffusion model delivers correct expressions for the radiative heat flow component and its temperature dependency. By conservation of energy, this result together with the additive approximation in turn allows determination, from calorimetric measurements, of also the non-radiative contributions to total heat transfer. The approach thus provides a key to subsequently analyse all heat transfer components by appropriate theoretical models. Since the temperature profile in the medium couples all heat transfer components to total heat flow, knowledge of the temperature dependence of also the non-radiative components is indispensable for this purpose. Besides calorimetric methods, spectral measurements of radiation extinction coefficient, and calculation of spectral extinction properties of disperse media by application of rigorous Mie-theory of scattering and of the Rosseland mean, provide another approach to radiative heat flow and to temperature dependent radiation extinction properties. Accordingly, comparison between results obtained from three different, completely independent methods (calorimetric, spectroscopic and theoretical) to determine extinction coefficients can be made and indeed proves to be successful if the medium is non-transparent; this proof of concept shall be demonstrated in the present thesis. In its first part, this thesis for habilitation presents a general review covering the literature on radiative transfer up to the year 1985 and evaluates methods for solution of the equation of radiative transfer also in case of strongly anisotropic scattering. Because of conservation of energy, and in view of the goal to analyse also the non-radiative heat transfer components, the analysis necessarily must include a description of the theoretical aspects of gaseous and solid/solid contact conduction heat transfer mechanisms. At the end of its first part, a catalogue of open questions is presented that will be tackled in the second part of the thesis. There, experimental and analytical/numerical results that verify the radiation diffusion model and its applicability to disperse media are reported. The analysis is focused on heat transfer in pure and opacified powders and fibrous media; both are easily accessible, disperse sample substances with well defined physical/thermal properties. An important part of these investigations covers thermal conductivity measurements under vacuum and under external mechanical load. Experimental results obtained with load-bearing, evacuated boards of glass fibre paper demonstrate smallest values of thermal conductivity that have been obtained until 1985 in such disperse media at high temperatures. The thesis further deals with the problem of how to substantially increase radiation extinction by optimum particle diameters. In particular, an exotic prediction of Mie theory of scattering shall be confirmed according to which the extinction properties of perfectly electrically conducting, long, extremely thin cylinders (below 50 nm) shall be larger, by orders of magnitude, than those of conventional, non-conducting powders or fibres, and samples shall be prepared. The thesis describes the way how to successfully prove this prediction (few years after submission of the thesis, following the methods suggested here and using finest metallised glass fibres, and with very thin Ni-fibres, Gustav Mie’s and Milton Kerker's predictions for the first time were confirmed in publications of the present author together with J. Fricke, M. Arduini-Schuster, H.-P. Ebert, R. Caps, D. Büttner und A. Kreh). KW - Strahlungstransport KW - Disperse Phase KW - Extinktion KW - Mie-Streuung KW - Wärmeleitung KW - Diffusionsmodell KW - Wirkungsquerschnitt KW - optimale Teilchendurchmesser KW - Superisolierung KW - Diffusion model KW - reaction cross section KW - optimum particle diameter KW - superinsulation Y1 - 1985 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-66669 N1 - Würzburg, Univ., Habil.-Schr., 1988 ER - TY - INPR A1 - Reiss, Harald T1 - Physical time and existence of time holes in non-transparent media N2 - The analysis presented in this paper applies to experimental situations where observers or objects to be studied (both stationary, with respect to each other) are located in environments the optical thickness of which is strongly different. By their large optical thickness, non-transparent media are clearly distinguished from their transparent counterparts. Non-transparent media comprise thin metallic films, packed or fluidised beds, the Earth’s crust, and even dark clouds and other cosmological objects. As a representative example, a non-transparent slab is subjected to transient disturbances, and a rigorous analysis is presented whether physical time reasonably could be constructed under such condition. The analysis incorporates mapping functions that correlate physical events, e, in non-transparent media, with their images, f(e), tentatively located on a standard physical time scale. The analysis demonstrates, however, that physical time, in its rigorous sense, does not exist under non-transparency conditions. A proof of this conclusion is attempted in three steps: i) the theorem “there is no time without space and events” is accepted, (ii) images f[e(s,t)] do not constitute a dense, uncountably infinite set, and (iii) sets of images that are not uncountably infinite do not create physical time but only time-like sequences. As a consequence, mapping f[e(s,t)] in non-transparent space does not create physical analogues to the mathematical structure of the ordered, dense half-set R+ of real numbers, and reverse mapping, f-1f[e(s,t)] would not allow unique identification and reconstruction of original events from their images. In these cases, causality and determinism, as well as invariance of physical processes under time reversal, might be violated. Existence of time holes could be possible, as follows from the sequence of images, f[e(s,t)], that is not uncountably infinite, in contrast to R+. Practical impacts are expected for understanding physical diffusion-like, radiative transfer processes, stability models to protect superconductors against quenchs or for description of their transient local pair density and critical currents. Impacts would be expected also in mathematical formulations (differential equations) of classical physics, in relativity and perhaps in quantum mechanics, all as far as transient processes in non-transparent space would be concerned. An interesting problem is whether temporal cloaking (a time hole) in a transparent medium, as very recently reported in the literature, can be explained by the present analysis. The analysis is not restricted to objects of laboratory dimensions: Because of obviously existing radiation transfer analogues, it is tempting to discuss consequences also for much larger structures in particular if an origin of time is postulated. KW - Strahlungstransport KW - Zeitrichtung KW - Supraleiter KW - Computersimulation KW - Non-transparency KW - disturbance KW - physical time KW - time hole Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-67268 N1 - Von diesem Artikel gibt es eine überarbeitete Version unter urn:nbn:de:bvb:20-opus-73554. ER - TY - JOUR A1 - Rauch, Bernhard A1 - Salzwedel, Annett A1 - Bjarnason-Wehrens, Birna A1 - Albus, Christian A1 - Meng, Karin A1 - Schmid, Jean-Paul A1 - Benzer, Werner A1 - Hackbusch, Matthes A1 - Jensen, Katrin A1 - Schwaab, Bernhard A1 - Altenberger, Johann A1 - Benjamin, Nicola A1 - Bestehorn, Kurt A1 - Bongarth, Christa A1 - Dörr, Gesine A1 - Eichler, Sarah A1 - Einwang, Hans-Peter A1 - Falk, Johannes A1 - Glatz, Johannes A1 - Gielen, Stephan A1 - Grilli, Maurizio A1 - Grünig, Ekkehard A1 - Guha, Manju A1 - Hermann, Matthias A1 - Hoberg, Eike A1 - Höfer, Stefan A1 - Kaemmerer, Harald A1 - Ladwig, Karl-Heinz A1 - Mayer-Berger, Wolfgang A1 - Metzendorf, Maria-Inti A1 - Nebel, Roland A1 - Neidenbach, Rhoia Clara A1 - Niebauer, Josef A1 - Nixdorff, Uwe A1 - Oberhoffer, Renate A1 - Reibis, Rona A1 - Reiss, Nils A1 - Saure, Daniel A1 - Schlitt, Axel A1 - Völler, Heinz A1 - Känel, Roland von A1 - Weinbrenner, Susanne A1 - Westphal, Ronja T1 - Cardiac rehabilitation in German speaking countries of Europe — evidence-based guidelines from Germany, Austria and Switzerland LLKardReha-DACH — Part 1 JF - Journal of Clinical Medicine N2 - Background: Although cardiovascular rehabilitation (CR) is well accepted in general, CR-attendance and delivery still considerably vary between the European countries. Moreover, clinical and prognostic effects of CR are not well established for a variety of cardiovascular diseases. Methods: The guidelines address all aspects of CR including indications, contents and delivery. By processing the guidelines, every step was externally supervised and moderated by independent members of the “Association of the Scientific Medical Societies in Germany” (AWMF). Four meta-analyses were performed to evaluate the prognostic effect of CR after acute coronary syndrome (ACS), after coronary bypass grafting (CABG), in patients with severe chronic systolic heart failure (HFrEF), and to define the effect of psychological interventions during CR. All other indications for CR-delivery were based on a predefined semi-structured literature search and recommendations were established by a formal consenting process including all medical societies involved in guideline generation. Results: Multidisciplinary CR is associated with a significant reduction in all-cause mortality in patients after ACS and after CABG, whereas HFrEF-patients (left ventricular ejection fraction <40%) especially benefit in terms of exercise capacity and health-related quality of life. Patients with other cardiovascular diseases also benefit from CR-participation, but the scientific evidence is less clear. There is increasing evidence that the beneficial effect of CR strongly depends on “treatment intensity” including medical supervision, treatment of cardiovascular risk factors, information and education, and a minimum of individually adapted exercise volume. Additional psychologic interventions should be performed on the basis of individual needs. Conclusions: These guidelines reinforce the substantial benefit of CR in specific clinical indications, but also describe remaining deficits in CR-delivery in clinical practice as well as in CR-science with respect to methodology and presentation. KW - cardiac rehabilitation standards KW - scientific guidelines KW - secondary prevention KW - coronary artery disease KW - chronic heart failure KW - heart valve repair KW - ICD-CRT KW - ventricular assist device KW - heart transplantation KW - peripheral artery disease KW - pulmonary hypertension KW - myocarditis KW - adults with congenital heart disease Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-239709 SN - 2077-0383 VL - 10 IS - 10 ER -