1.

Record Nr.

UNINA9910299921803321

Autore

Li Dan

Titolo

Rail Crack Monitoring Using Acoustic Emission Technique / / by Dan Li

Pubbl/distr/stampa

Singapore : , : Springer Singapore : , : Imprint : Springer, , 2018

ISBN

981-10-8348-7

Edizione

[1st ed. 2018.]

Descrizione fisica

1 online resource (157 pages)

Collana

Springer Theses, Recognizing Outstanding Ph.D. Research, , 2190-5053

Disciplina

363.122810979436

Soggetti

Acoustical engineering

Materials science

Acoustics

Engineering Acoustics

Characterization and Evaluation of Materials

Lingua di pubblicazione

Inglese

Formato

Materiale a stampa

Livello bibliografico

Monografia

Nota di contenuto

Introduction -- Literature review -- Propagation features and source location -- Sizing of fatigue cracks -- Field monitoring of rail cracks -- Conclusions and future work.

Sommario/riassunto

This thesis provides an innovative strategy for rail crack monitoring using the acoustic emission (AE) technique. The field study presented is a significant improvement on laboratory studies in the literature in terms of complex rail profile and crack conditions as well as high operational noise. AE waves induced by crack propagation, crack closure, wheel-rail impact and operational noise were obtained through a series of laboratory and field tests, and analyzed by wavelet transform (WT) and synchrosqueezed wavelet transform (SWT). A wavelet power-based index and the enhanced SWT scalogram were sequentially proposed to classify AE waves induced by different mechanisms according to their energy distributions in the time–frequency domain. A novel crack sizing method taking advantage of crack closure-induced AE waves was developed based on fatigue tests in the laboratory. The propagation characteristics of AE waves in the rail were investigated, and Tsallis synchrosqueezed wavelet entropy (TSWE) with time was finally brought forward to detect and locate rail



cracks in the field. The proposed strategy for detection, location and sizing of rail cracks helps to ensure the safe and smooth operation of the railway system. This thesis is of interest to graduate students, researchers and practitioners in the area of structural health monitoring.

2.

Record Nr.

UNINA9910261094203321

Autore

Tschernjajew Anatolij

Titolo

Michail Gorbatschow und die deutsche Frage : Sowjetische Dokumente 1986-1991 / / Aleksandr Galkin, Anatolij Tschernjajew

Pubbl/distr/stampa

De Gruyter, 2011

Berlin ; ; Boston : , : Oldenbourg Wissenschaftsverlag, , [2012]

©2011

Edizione

[1st ed.]

Descrizione fisica

1 online resource (676 pages) : illustrations

Collana

Quellen und Darstellungen zur Zeitgeschichte ; ; 83

Classificazione

HIS000000HIS014000HIS037070

Disciplina

943.704

Soggetti

Helmut Kohl

Michail Gorbatschow

Wiedervereinigung

HISTORY / General

Soviet Union Politics and government 1985-1991 Sources

Soviet Union Foreign relations Germany Sources

Lingua di pubblicazione

Tedesco

Formato

Materiale a stampa

Livello bibliografico

Monografia

Note generali

Bibliographic Level Mode of Issuance: Monograph

Nota di bibliografia

Includes bibliographical references.

Nota di contenuto

Front Matter -- Dokumente -- 1986 -- 1987 -- 1988 -- 1989 -- 1990 -- 1991 -- Back Matter

Sommario/riassunto

im Prozess der deutschen Wiedervereinigung spielte die Sowjetunion eine zentrale Rolle. Die wesentlichen Dokumente aus dem innersten Machtzirkel der UdSSR, die Motive und Entscheidungsfindungen des Kreml beleuchten, waren indes bislang nur einem kleinen Kreis von Spezialisten zugänglich. Die vorliegende Edition bietet erstmals eine vollständige deutsche Übersetzung derjenigen sowjetischen Gesprächsprotokolle, Strategiepapiere und Hintergrunddiskussionen,



die die Gorbatschow-Stiftung 2006 in Russland publiziert hat. Die intensive Kommentierung führt zugleich die vielfältigen westlichen und russischen Gegen- und Parallelversionen aus offiziellen Editionen und aus der umfangreichen Memoirenliteratur zusammen. In den Texten wird die Dramatik der Jahre 1989 und 1990 greifbar. Deutsche, sowjetische, europäische und globale Ereignisse stellten Moskau vor immer neue Herausforderungen - mit der Zustimmung zur Wiedervereinigung versuchte Gorbatschow auch, die komplexen, miteinander verzahnten innen- und außenpolitischen Probleme der UdSSR zu lösen.