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<export-example>
  <doc>
    <id>34573</id>
    <completedYear/>
    <publishedYear>2015</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>16</pageFirst>
    <pageLast>22</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>63</volume>
    <type>article</type>
    <publisherName>Elsevier B.V.</publisherName>
    <publisherPlace>Amsterdam</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Influence of thermodynamic properties of a thermo-acoustic emitter on the efficiency of thermal airborne ultrasound generation</title>
    <abstract language="eng">In this work we experimentally verify the theoretical prediction of the recently published Energy Density Fluctuation Model (EDF-model) of thermo-acoustic sound generation. Particularly, we investigate experimentally the influence of thermal inertia of an electrically conductive film on the efficiency of thermal airborne ultrasound generation predicted by the EDF-model. Unlike widely used theories, the EDF-model predicts that the thermal inertia of the electrically conductive film is a frequency-dependent parameter. Its influence grows non-linearly with the increase of excitation frequency and reduces the efficiency of the ultrasound generation. Thus, this parameter is the major limiting factor for the efficient thermal airborne ultrasound generation in the MHz-range. To verify this theoretical prediction experimentally, five thermo-acoustic emitter samples consisting of Indium-Tin-Oxide (ITO) coatings of different thicknesses (from 65 nm to 1.44 lm) on quartz glass substrates were tested for airborne ultrasound generation in a frequency range from 10 kHz to 800 kHz. For the measurement of thermally generated sound pressures a laser Doppler vibrometer combined with a 12 lm thin polyethylene foil was used as the sound pressure detector. All tested thermo-acoustic emitter samples showed a resonance-free frequency response in the entire tested frequency range. The thermal inertia of the heat producing film acts as a low-pass filter and reduces the generated sound pressure with the increasing excitation frequency and the ITO film thickness. The difference of generated sound pressure levels for samples with 65 nm and 1.44 lm thickness is in the order of about 6 dB at 50 kHz and of about 12 dB at 500 kHz. A comparison of sound pressure levels measured experimentally and those predicted by the EDF-model shows for all tested emitter samples a relative error of less than ±6%. Thus, experimental results confirm the prediction of the EDF-model and show that the model can be applied for design and optimization of thermo-acoustic airborne ultrasound emitters.</abstract>
    <parentTitle language="eng">Ultrasonics</parentTitle>
    <identifier type="old">37709</identifier>
    <identifier type="doi">10.1016/j.ultras.2015.06.008</identifier>
    <identifier type="issn">0041-624x</identifier>
    <enrichment key="date_peer_review">16.10.2015</enrichment>
    <author>Maxim Daschewski</author>
    <author>Marc Kreutzbruck</author>
    <author>Jens Prager</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Thermophone</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Thermo-acoustic effect</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Thermal sound generation</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Resonance-free ultrasound emitter</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Energy density fluctuation</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Thermal inertia</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>32733</id>
    <completedYear/>
    <publishedYear>2015</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst>156</pageFirst>
    <pageLast>166</pageLast>
    <pageNumber/>
    <edition/>
    <issue>3</issue>
    <volume>82</volume>
    <type>article</type>
    <publisherName>Oldenbourg</publisherName>
    <publisherPlace>München</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Resonanzfreie Messung und Anregung von Ultraschall</title>
    <abstract language="deu">In diesem Beitrag präsentieren wir innovative Methoden für die breitbandige und resonanzfreie Messung und Anregung von Ultraschall. Das Messverfahren verwendet eine Kunststofffolie und ein Laser-Vibrometer als breitbandigen und resonanzfreien Empfänger. Im Allgemeinen ermöglicht dieses Verfahren eine präzise Messung der Schallschnelle und des Schalldruckes in beliebigen, für das Laserlicht transparenten Flüssigkeiten und Gasen mit bekannter Dichte und Schallgeschwindigkeit. Das resonanzfreie Senden von Ultraschall basiert auf einem elektro-thermo-akustischen Wandlerprinzip und ermöglicht, im Gegensatz zu herkömmlichen Ultraschallwandlern, die Erzeugung von beliebig geformten akustischen Signalen ohne Resonanzen und ohne Nachschwingen.</abstract>
    <abstract language="eng">In this contribution we present innovative methods for broadband and resonance-free sensing and emitting of ultrasound. The sensing method uses a polyethylene foil and a laser vibrometer as a broadband and resonance-free sound receiver. In general, this method enables absolute measurement of sound particle velocity and sound pressure in arbitrary, laser beam transparent liquids and gases with known density and sound velocity. The resonance-free emitting method is based on the electro-thermo-acoustic principle and enables, contrary to conventional ultrasound transducers, generation of arbitrary shaped acoustic signals without resonances and post-oscillations.</abstract>
    <parentTitle language="deu">Technisches Messen</parentTitle>
    <identifier type="old">35809</identifier>
    <identifier type="doi">10.1515/teme-2014-0020</identifier>
    <identifier type="issn">0340-837X</identifier>
    <identifier type="issn">0178-2312</identifier>
    <identifier type="issn">0171-8096</identifier>
    <enrichment key="date_peer_review">12.03.2015</enrichment>
    <author>Maxim Daschewski</author>
    <author>Marc Kreutzbruck</author>
    <author>Jens Prager</author>
    <author>Elmar Dohse</author>
    <author>Mate Gaal</author>
    <author>Andrea Harrer</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Ultraschall</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Übertragungsfunktion</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Charakterisierung von Ultraschallmesssystemen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Thermo-akustische Ultraschallemitter</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasound</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Transfer function</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Characterization of ultrasonic measurement systems</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Thermo-acoustic ultrasound emitter</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>31132</id>
    <completedYear/>
    <publishedYear>2014</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst>790</pageFirst>
    <pageLast>791</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation>Deutsche Gesellschaft für Akustik e.V.</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Ein neues Modell zur Beschreibung der thermo-akustischen Schallerzeugung</title>
    <abstract language="deu">In unserem Beitrag präsentieren wir ein verallgemeinertes physikalisches Modell der thermischen Schallerzeugung. Im Gegensatz zur existierenden analytischen Näherungen erlaubt es eine exakte analytische Vorhersage des thermisch generierten Schalldrucks in Fluiden und Festkörpern, berücksichtigt die akustischen Nahefeld- und Schallschwächungseffekte und ist anwendbar für beliebige thermische Energiequellen, wie stromdurchflossene elektrische Leiter aber auch chemische Reaktionen, Plasmabrennen oder Laseranregung. Zur Verifikation des Modells vergleichen wir die analytischen Ergebnisse mit experimentellen Schalldruckmessungen an thermo-akustischen Emittern in Luft in einem Frequenzband von 4 kHz bis 1 MHz. Zusätzlich wurde die Effizienz der Wandler mit der von konventionellen piezoelektrischen Luftultraschallwandlern verglichen. Da die Schallerzeugung ohne mechanisch bewegliche Komponenten auskommt, arbeiten die thermo-akustischen Emitter resonanzfrei. Somit ist es möglich, beliebig geformte Schallsignale exakt und frei von Nachschwingen zu erzeugen. Thermo-akustische Schallemitter haben damit das Potenzial für eine breite Anwendung in der angewandten Akustik als leistungsfähige und resonanzfreie Schallsender mit einer Bandbreite bis in den Subgigahertz-Bereich.</abstract>
    <parentTitle language="deu">DAGA 2014 - 40. Jahrestagung für Akustik - Fortschritte der Akustik</parentTitle>
    <identifier type="old">34126</identifier>
    <identifier type="isbn">978-3-939296-06-5</identifier>
    <enrichment key="eventName">DAGA 2014 - 40. Jahrestagung für Akustik</enrichment>
    <enrichment key="eventPlace">Oldenburg, Germany</enrichment>
    <enrichment key="eventStart">10.03.2014</enrichment>
    <enrichment key="eventEnd">13.03.2014</enrichment>
    <author>Maxim Daschewski</author>
    <author>Marc Kreutzbruck</author>
    <author>Jens Prager</author>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>22971</id>
    <completedYear/>
    <publishedYear>2010</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst>650</pageFirst>
    <pageLast>657</pageLast>
    <pageNumber/>
    <edition/>
    <issue>C5/115</issue>
    <volume/>
    <type>bookpartcollection</type>
    <publisherName>VDE-Verl.</publisherName>
    <publisherPlace>Berlin; Offenbach</publisherPlace>
    <creatingCorporation>Informationstechnische Gesellschaft im VDE (ITG); VDI/VDE-Gesellschaft Mess- und Automatisierungstechnik (GMA)</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">SAFT und TOFD - Ein Vergleich im Analyseverhalten von Reflektoren</title>
    <parentTitle language="deu">15. ITG/GMA-Fachtagung - Sensoren und Messsysteme 2010 (Proceedings)</parentTitle>
    <identifier type="old">25533</identifier>
    <identifier type="isbn">978-3-8007-3260-9</identifier>
    <enrichment key="bibliotheksstandort">Sonderstandort: Publica-Schrank</enrichment>
    <enrichment key="eventName">15. ITG/GMA-Fachtagung - Sensoren und Messsysteme 2010</enrichment>
    <enrichment key="eventPlace">Nürnberg, Deutschland</enrichment>
    <enrichment key="eventStart">2010-05-18</enrichment>
    <enrichment key="eventEnd">2010-05-19</enrichment>
    <author>Jessica Kitze</author>
    <author>Daniel Brackrock</author>
    <author>Gerhard Brekow</author>
    <author>Jens Prager</author>
    <author>Mate Gaal</author>
    <author>Marc Kreutzbruck</author>
    <author>D. Szabo</author>
    <author>K. Kuti</author>
    <author>G. Paczolay</author>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")</collection>
  </doc>
  <doc>
    <id>22972</id>
    <completedYear/>
    <publishedYear>2010</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>10</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation>European federation for non-destructive testing (EFNDT)</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Flaw detection with guided waves using phased array technique</title>
    <abstract language="eng">Guided waves travel in plates and hollow cylinders over large distances and propagate with multiple mode shapes. Therefore the waves can be used viably for integrity tests of large scale structures. The number of propagating modes increases with frequency. Due to their dispersive character the different modes are manageable only in a limited frequency range. Depending on the wave length and on the angle of impingement of the wave front to the coupling surface between transducer and structure, a trace wavelength is predefined and a selective excitation of single modes becomes feasible. By using phased array technique the excited wave mode can be selected by controlling the input signal of the transducer. Different modes are excitable with a sin-gle mechanical set-up. In a first step of the investigation, a calculation model is developed modelling the wave propagation and the selective excitation of guided wave modes depending on the control parameters. Dedicated experiments show the applicability of the method presented. The flaw detection of different sized cracks and of material thickness reductions is examined depending on the excitation wave mode.</abstract>
    <parentTitle language="eng">ECNDT 2010 - 10th European conference on non-destructive testing (Proceedings)</parentTitle>
    <identifier type="old">25534</identifier>
    <identifier type="isbn">978-1-617-82791-4</identifier>
    <enrichment key="bibliotheksstandort">Sonderstandort: Publica-Schrank</enrichment>
    <enrichment key="eventName">ECNDT 2010 - 10th European conference on non-destructive testing</enrichment>
    <enrichment key="eventPlace">Moscow, Russia</enrichment>
    <enrichment key="eventStart">2010-06-07</enrichment>
    <enrichment key="eventEnd">2010-06-11</enrichment>
    <author>Jens Prager</author>
    <author>Carsten Hoever</author>
    <author>Gerhard Brekow</author>
    <author>Marc Kreutzbruck</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic testing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Guided waves</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Plate-like structures</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")</collection>
  </doc>
  <doc>
    <id>20339</id>
    <completedYear/>
    <publishedYear>2009</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>203</pageFirst>
    <pageLast>212</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>bookpartcollection</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation>German Society for NDT</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Flaw detection with guided waves using phased array technique</title>
    <parentTitle language="eng">5th International workshop of NDT experts - NDT in progress 2009 (Proceedings)</parentTitle>
    <identifier type="old">22630</identifier>
    <identifier type="isbn">978-80-214-3968-9</identifier>
    <enrichment key="bibliotheksstandort">Sonderstandort: Publica-Schrank</enrichment>
    <enrichment key="eventName">5th International workshop of NDT experts - NDT in progress 2009</enrichment>
    <enrichment key="eventPlace">Prague, Czech Republic</enrichment>
    <enrichment key="eventStart">2009-10-12</enrichment>
    <enrichment key="eventEnd">2009-10-14</enrichment>
    <author>Jens Prager</author>
    <author>Carsten Hoever</author>
    <author>Gerhard Brekow</author>
    <author>Marc Kreutzbruck</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic testing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Guided waves</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Plate-like structures</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")</collection>
  </doc>
  <doc>
    <id>20516</id>
    <completedYear/>
    <publishedYear>2009</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst>1</pageFirst>
    <pageLast>7</pageLast>
    <pageNumber/>
    <edition/>
    <issue>DGZfP-BB 115 ( Di.1.A.2)</issue>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation>Deutsche Gesellschaft für Zerstörungsfreie Prüfung e.v. (DGZfP)</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Fehlernachweis mit Plattenwellen und Luftultraschall</title>
    <parentTitle language="deu">DGZfP-Jahrestagung 2009</parentTitle>
    <identifier type="old">22821</identifier>
    <identifier type="isbn">978-3-940283-16-0</identifier>
    <enrichment key="bibliotheksstandort">Sonderstandort: Publica-Schrank</enrichment>
    <enrichment key="eventName">DGZfP-Jahrestagung 2009</enrichment>
    <enrichment key="eventPlace">Münster, Deutschland</enrichment>
    <enrichment key="eventStart">2009-05-18</enrichment>
    <enrichment key="eventEnd">2009-05-20</enrichment>
    <author>Mate Gaal</author>
    <author>Joachim Döring</author>
    <author>Jens Prager</author>
    <author>Gerhard Brekow</author>
    <author>Marc Kreutzbruck</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Plattenwellen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Luftultraschall</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Ultraschallprüfung</value>
    </subject>
    <collection role="literaturgattung" number="">Eigenverlag BAM</collection>
    <collection role="fulltextaccess" number="">Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")</collection>
  </doc>
  <doc>
    <id>20519</id>
    <completedYear/>
    <publishedYear>2009</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst>1</pageFirst>
    <pageLast>8</pageLast>
    <pageNumber/>
    <edition/>
    <issue>DGZfP-BB 115 (Poster 35)</issue>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation>Deutsche Gesellschaft für Zerstörungsfreie Prüfung e.v. (DGZfP)</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Fehlernachweis mit geführten Wellen unter Verwendung der Gruppenstrahlertechnik</title>
    <parentTitle language="deu">DGZfP-Jahrestagung 2009</parentTitle>
    <identifier type="old">22824</identifier>
    <identifier type="isbn">978-3-940283-16-0</identifier>
    <enrichment key="bibliotheksstandort">Sonderstandort: Publica-Schrank</enrichment>
    <enrichment key="eventName">DGZfP-Jahrestagung 2009</enrichment>
    <enrichment key="eventPlace">Münster, Deutschland</enrichment>
    <enrichment key="eventStart">2009-05-18</enrichment>
    <enrichment key="eventEnd">2009-05-20</enrichment>
    <author>Carsten Hoever</author>
    <author>Jens Prager</author>
    <author>Gerhard Brekow</author>
    <author>Marc Kreutzbruck</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Geführte Wellen</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Gruppenstrahlertechnik</value>
    </subject>
    <collection role="literaturgattung" number="">Eigenverlag BAM</collection>
    <collection role="fulltextaccess" number="">Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")</collection>
  </doc>
  <doc>
    <id>21883</id>
    <completedYear/>
    <publishedYear>2010</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst>1</pageFirst>
    <pageLast>5</pageLast>
    <pageNumber/>
    <edition/>
    <issue>DGZfP-BB 122 (P41)</issue>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace>Berlin</publisherPlace>
    <creatingCorporation>Deutsche Gesellschaft für Zerstörungsfreie Prüfung e.V. (DGZfP)</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Untersuchungen zur Anregung geführter Wellen in Platten mittels Gruppenstrahlertechnik</title>
    <abstract language="deu">Geführte Wellen breiten sich in Platten und Hohlzylindern über weite
Entfernungen aus. Aus dieser Eigenschaft ergibt sich ein hohes Anwendungspotential
dieser Wellenart für die zerstörungsfreie Prüfung ausgedehnter Bauteile und
Strukturen mittels Ultraschall. Nachteilig für die Anwendung geführter Wellen sind
ihr dispersives Verhalten und die zunehmende Anzahl ausbreitungsfähiger Wellenmoden
bei hohen Frequenzen.
Ziel des Einsatzes der Gruppenstrahlertechnik ist es, eine ausgewählte Wellenmode
selektiv anzuregen bzw. zu empfangen. Durch die Änderung des Schwenkwinkels
im Gruppenstrahlerprüfkopf wird eine definierte Spurwellenlänge auf dem
Interface zwischen Prüfkopf und Struktur festgelegt, die zur Anregung einer Welle
mit entsprechender Phasengeschwindigkeit führt. Da der Schwenkwinkel elektronisch
verändert werden kann, lässt sich auch die angeregte Wellenmode elektronisch
auswählen, worin der große Vorteil des vorgestellten Verfahrens liegt.
In den vorgestellten Untersuchungen wurde die Anwendbarkeit der Methode
experimentell demonstriert. Der Anregemechanismus wurde theoretisch beleuchtet
und die Wellenausbreitung im Prüfkopf mit verschiedenen analytischen Ansätzen
modelliert. Mit diesen Modellen können Fragen der Richtwirkung und der Effizienz
der Anregung detailliert untersucht werden. Die modellierten Wellenfelder
wurden mit den experimentellen Ergebnissen verglichen und die Anwendbarkeit
der theoretischen Ansätze beurteilt, wobei die Ergebnisse der theoretischen Untersuchungen
im Experiment verifiziert werden konnten.</abstract>
    <parentTitle language="deu">DGZfP-Jahrestagung 2010</parentTitle>
    <identifier type="old">24346</identifier>
    <identifier type="isbn">978-3-940283-26-9</identifier>
    <enrichment key="bibliotheksstandort">Sonderstandort: Publica-Schrank</enrichment>
    <enrichment key="eventName">DGZfP-Jahrestagung 2010</enrichment>
    <enrichment key="eventPlace">Erfurt, Deutschland</enrichment>
    <enrichment key="eventStart">2010-05-10</enrichment>
    <enrichment key="eventEnd">2010-05-12</enrichment>
    <author>Jens Prager</author>
    <author>C. Hoever</author>
    <author>Marc Kreutzbruck</author>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")</collection>
  </doc>
  <doc>
    <id>21880</id>
    <completedYear/>
    <publishedYear>2010</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst>1</pageFirst>
    <pageLast>11</pageLast>
    <pageNumber/>
    <edition/>
    <issue>DGZfP-BB 122 (Mi.2.A.3)</issue>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace>Berlin</publisherPlace>
    <creatingCorporation>Deutsche Gesellschaft für Zerstörungsfreie Prüfung e.V. (DGZfP)</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">SAFT und TOFD - Ein Vergleich im Analyseverhalten von Reflektoren</title>
    <abstract language="deu">Mit der Gruppenstrahlertechnik der Bundesanstalt für
Materialforschung und -prüfung sind umfangreiche Untersuchungen an einer
plattierten Druckbehälter-Testwand durchgeführt worden. In der vorliegenden
Testwand mit einer Wanddicke von 149 mm befinden sich künstliche
Testreflektoren im Schweißnaht- und Plattierungsbereich, die mit Gruppenstrahler-
Prüfköpfen mit unterschiedlichen Frequenzen, Einschallwinkeln und
Einschallrichtungen nachgewiesen und in ihrem Anzeigenverhalten analysiert
wurden.
Zur Rekonstruktion der Reflektoranzeigen wurde ein SAFT - Algorithmus
verwendet, der die Variation der Einschallwinkel berücksichtigt. Zum Vergleich
sind die Reflektoren auch mit der TOFD - Technik analysiert worden. Ziel der
Untersuchungen war der direkte Vergleich der Eignung der SAFT- und TOFDTechnik
zur quantitativen Reflektorgrößenbestimmung.</abstract>
    <parentTitle language="deu">DGZfP-Jahrestagung 2010</parentTitle>
    <identifier type="old">24343</identifier>
    <identifier type="isbn">978-3-940283-26-9</identifier>
    <enrichment key="bibliotheksstandort">Sonderstandort: Publica-Schrank</enrichment>
    <enrichment key="eventName">DGZfP-Jahrestagung 2010</enrichment>
    <enrichment key="eventPlace">Erfurt, Deutschland</enrichment>
    <enrichment key="eventStart">2010-05-10</enrichment>
    <enrichment key="eventEnd">2010-05-12</enrichment>
    <author>Jessica Kitze</author>
    <author>Daniel Brackrock</author>
    <author>Gerhard Brekow</author>
    <author>Jens Prager</author>
    <author>Mate Gaal</author>
    <author>Marc Kreutzbruck</author>
    <author>D. Szabo</author>
    <author>K. Kuti</author>
    <author>G. Paczolay</author>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")</collection>
  </doc>
  <doc>
    <id>25232</id>
    <completedYear/>
    <publishedYear>2010</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>10</pageLast>
    <pageNumber/>
    <edition/>
    <issue>DGZfP-BB 125 (Th.1.C.3)</issue>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace>Berlin</publisherPlace>
    <creatingCorporation>Deutsche Gesellschaft für Zerstörungsfreie Prüfung (DGZfP)</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Acoustic wave energy skewing and coefficients for the reflected and transmitted plane waves in general homogeneous transversely-isotropic austenitic materials</title>
    <abstract language="eng">In this contribution a simulation tool is developed to compute the energy skewing angles and energy coefficients
for the reflected and refracted plane waves in following general cases: (1) reflection and refraction
of plane elastic waves at an interface between isotropic and transversely isotropic solid, (2) reflection
and refraction of plane elastic waves at an interface between transversely isotropic and isotropic solid, (3)
reflection and refraction of plane elastic waves at an interface between two general transversely isotropic
solid and (4) reflection of plane elastic waves from a stress free boundary of a transversely isotropic solid.
Computational results for analytically evaluated acoustic wave energy skewing angles and energy reflection
and transmission coefficients in acoustically anisotropic materials such as austenitic steel materials
exhibiting columnar grain orientation are presented. The obtained results show that the acoustic energy
skewing angles and coefficients in austenitic steel materials strongly depend upon the columnar grain
orientation and are less influenced by the grain orientations which are parallel and perpendicular to the
interface.</abstract>
    <parentTitle language="eng">8th International conference on NDE in relation to structural integrity for nuclear and pressurised components (DGZfP-Proceedings)</parentTitle>
    <identifier type="old">27940</identifier>
    <identifier type="isbn">978-3-940283-30-6</identifier>
    <enrichment key="bibliotheksstandort">Sonderstandort: Publica-Schrank</enrichment>
    <enrichment key="eventName">8th International conference on NDE in relation to structural integrity for nuclear and pressurised components</enrichment>
    <enrichment key="eventPlace">Berlin, Germany</enrichment>
    <enrichment key="eventStart">2010-09-29</enrichment>
    <enrichment key="eventEnd">2010-10-01</enrichment>
    <author>Sanjeevareddy Kolkoori</author>
    <author>Mehbub-Ur Rahman</author>
    <author>Jens Prager</author>
    <author>Marc Kreutzbruck</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Anisotropy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Austenitic weld material</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Energy skewing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Critical angle</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Energy flux vector</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Energy coefficients</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")</collection>
  </doc>
  <doc>
    <id>25328</id>
    <completedYear/>
    <publishedYear>2011</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst>339</pageFirst>
    <pageLast>340</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation>Deutsche Gesellschaft für Akustik e.V.</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Erzeugung von Luftultraschall mit mikro- und nanostrukturierten Kohlenstoffmaterialien unter Ausnutzung des thermoakustischen Prinzips</title>
    <abstract language="deu">In diesem Beitrag wird ein neuartiger Ansatz zur Erzeugung von Luftultraschall vorgestellt, der auf dem thermoakustischen Prinzip beruht. Mikro- und nanostrukturierte Kohlenstoffmaterialien werden dabei mit einem harmonischen Wechselstrom gespeist und erfahren durch ohmsche Verluste eine Temperaturänderung, die sich auf das umgebende Fluid überträgt. Daraus resultieren Druckmodulationen, und es wird eine ausbreitungsfähige Schallwelle erzeugt. Dabei tritt Frequenzverdopplung gegenüber der Anregungsfrequenz auf. Es konnte gezeigt werden, dass der entscheidende Parameter für die Effizienz der Methode, d.h. für ein möglichst großes Verhältnis von Schalldruck zu eingebrachter Leistung, die Wärmekapazität pro Flächeneinheit ist. Da dieser Quotient für Kohlenstoffmaterialien sehr klein sein kann, erlaubt das thermoakustische Prinzip hier die effiziente Erzeugung von Luftultraschall. Schalldruckmessungen an verschiedenen Materialproben wurden bis 100 kHz mit einem Mikrofon durchgeführt, oberhalb von 100 kHz wurde eine laservibrometrische Schnellemessung eingesetzt. In experimentellen Untersuchungen wurde die Schallerzeugung in Abhängigkeit der Materialeigenschaften analysiert und systematisiert. Die experimentellen Ergebnisse wurden mit numerischen und analytischen Berechnungsergebnissen verglichen.</abstract>
    <parentTitle language="deu">DAGA 2011 - 37. Jahrestagung für Akustik - Fortschritte der Akustik</parentTitle>
    <identifier type="old">28038</identifier>
    <identifier type="isbn">978-3-939296-02-7</identifier>
    <enrichment key="eventName">DAGA 2011 - 37. Jahrestagung für Akustik - Fortschritte der Akustik</enrichment>
    <enrichment key="eventPlace">Düsseldorf, Germany</enrichment>
    <enrichment key="eventStart">21.03.2011</enrichment>
    <enrichment key="eventEnd">24.03.2011</enrichment>
    <author>Andrea Harrer</author>
    <author>Jens Prager</author>
    <author>Marc Kreutzbruck</author>
    <author>Matthias Guderian</author>
    <author>Asmus Meyer-Plath</author>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Thermoakustisches Prinzip</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Luftultraschall</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Kohelnstoffmaterialien</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>27736</id>
    <completedYear/>
    <publishedYear>2013</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1043</pageFirst>
    <pageLast>1050</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>1511</volume>
    <type>conferenceobject</type>
    <publisherName>AIP Publishing</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">A comparative study of ray tracing and CIVA simulation for ultrasonic examination of anisotropic inhomogeneous austenitic welds</title>
    <abstract language="eng">Ultrasonic examination of anisotropic inhomogeneous austenitic welds is challenging, because of the columnar grain structure of the weld leads to beam skewing and splitting. Modeling tools play an important role in understanding the ultrasound field propagation and optimization of experimental parameters during the ultrasonic testing of austenitic welds as well as the interpretation of the test results. In this contribution, an efficient theoretical model based on the ray tracing concepts is developed to calculate the ultrasonic fields in inhomogeneous austenitic welds quantitatively. The developed model determines the ultrasound fields by taking into account the directivity of the ray source, the inhomogenity of the weld as well as ray transmission coefficients. Directivity of the ray source in columnar grained austenitic materials (including layback orientation) is obtained in three dimensions based on Lamb's reciprocity theorem. Ray energy reflection and transmission coefficients at an interface between two general columnar grained austenitic materials are calculated in three dimensions. The ray tracing model predictions on inhomogeneous austenitic weld material are compared against those from CIVA, a commercial non-destructive modeling and simulation tool. The ultrasonic modeling tools in CIVA are based on semi-analytical solutions. For beam propagation simulation, a so-called 'pencil method' is used, which involves modeling the probe as a set of individual source points, each radiating 'a bundle' of diverging rays into the medium and integrating those elementary contributions. Inhomogenity in the weld region is approximated by mapping the grain orientations on weld macrograph. Simulation results for ultrasonic field profiles for an austenitic weld are shown to be in good agreement with the corresponding experimental results.</abstract>
    <parentTitle language="eng">39th Annual review of progress in quantitative nondestructive evaluation (Proceedings)</parentTitle>
    <identifier type="old">30570</identifier>
    <identifier type="isbn">978-0-7354-1129-6</identifier>
    <identifier type="doi">10.1063/1.4789158</identifier>
    <identifier type="issn">0094-243X</identifier>
    <identifier type="issn">1551-7616</identifier>
    <note>Serientitel: AIP conference proceedings – Series title: AIP conference proceedings</note>
    <enrichment key="eventName">39th Annual review of progress in quantitative nondestructive evaluation</enrichment>
    <enrichment key="eventPlace">Denver, Colorado, USA</enrichment>
    <enrichment key="eventStart">15.07.2012</enrichment>
    <enrichment key="eventEnd">20.07.2012</enrichment>
    <enrichment key="date_peer_review">25.02.2013</enrichment>
    <author>Sanjeevareddy Kolkoori</author>
    <author>Parisa Shokouhi</author>
    <author>Christian Höhne</author>
    <author>Mehbub-Ur Rahman</author>
    <author>Marc Kreutzbruck</author>
    <author>Jens Prager</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Crystal microstructure</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ray tracing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic materials testing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic propagation</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic reflection</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic transmission</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Welds</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>26788</id>
    <completedYear/>
    <publishedYear>2012</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>624</pageFirst>
    <pageLast>627</pageLast>
    <pageNumber/>
    <edition/>
    <issue>1433</issue>
    <volume/>
    <type>conferenceobject</type>
    <publisherName>American Institute of Physics</publisherName>
    <publisherPlace>Melville, NY</publisherPlace>
    <creatingCorporation>University of Gdansk, Poland</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Carbon nanomaterials as broadband airborne ultrasound transducer</title>
    <abstract language="eng">A method has been developed for the generation of airborne ultrasound using the thermoacoustic principle applied to carbon materials at the micro- and nanoscale. Such materials are shown to be capable to emitting the ultrasound. We tested the acoustic performance of electrospun polyacrylonitrile-derived carbon nanofibers tissues and determined the sound pressure for frequencies up to 350 kHz. The experimental results are compared to analytic calculations.</abstract>
    <parentTitle language="eng">International congress on ultrasonics</parentTitle>
    <identifier type="old">29570</identifier>
    <identifier type="isbn">978-0-7354-1019-0</identifier>
    <identifier type="doi">10.1063/1.3703262</identifier>
    <identifier type="issn">0094-243X</identifier>
    <note>Serientitel: AIP conference proceedings – Series title: AIP conference proceedings</note>
    <enrichment key="bibliotheksstandort">Sonderstandort: Publica-Schrank</enrichment>
    <enrichment key="eventName">International congress on ultrasonics</enrichment>
    <enrichment key="eventPlace">Gdansk, Poland</enrichment>
    <enrichment key="eventStart">2011-09-05</enrichment>
    <enrichment key="eventEnd">2011-09-08</enrichment>
    <enrichment key="date_peer_review">25.10.2012</enrichment>
    <author>Maxim Daschewski</author>
    <author>Andrea Harrer</author>
    <author>Jens Prager</author>
    <author>Marc Kreutzbruck</author>
    <author>Matthias Guderian</author>
    <author>Asmus Meyer-Plath</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Thermoacoustic</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Airborne ultrasound transducer</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Sound pressure</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")</collection>
  </doc>
  <doc>
    <id>29152</id>
    <completedYear/>
    <publishedYear>2012</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>965</pageFirst>
    <pageLast>967</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation>Institute of Electrical and Electronics Engineers (IEEE)</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Metallic nanofilm as resonance-free airborne ultrasound emitter</title>
    <abstract language="eng">A novel approach for the generation of broadband airborne ultrasound by using the thermo-acoustic effect is presented in this contribution. We investigate the applicability of resonance-free thermo-acoustic emitters for generation of very short high pressure airborne ultrasound pulses. A thermoacoustic emitter consisting of a 30 nm thin metallic film on a usual soda-lime glass substrate generates sound pressure values of more than 140 dB at 60 mm distance. The results are compared with conventional piezoelectric airborne ultrasound transducers. Our investigations show the applicability of the thermo-acoustic devices for broadband and high pressure ultrasound emitters using pulse excitation.</abstract>
    <parentTitle language="eng">IUS 2012 -  IEEE International Ultrasonics Symposium (Proceedings)</parentTitle>
    <identifier type="old">32054</identifier>
    <identifier type="isbn">978-1-4673-4562-0</identifier>
    <identifier type="doi">10.1109/ULTSYM.2012.0241</identifier>
    <identifier type="issn">1948-5719</identifier>
    <enrichment key="bibliotheksstandort">Sonderstandort: Publica-Schrank</enrichment>
    <enrichment key="eventName">2012 IEEE International Ultrasonics Symposium (IUS)</enrichment>
    <enrichment key="eventPlace">Dresden, Germany</enrichment>
    <enrichment key="eventStart">2012-10-07</enrichment>
    <enrichment key="eventEnd">2012-10-10</enrichment>
    <enrichment key="date_peer_review">26.09.2013</enrichment>
    <author>Maxim Daschewski</author>
    <author>Andrea Harrer</author>
    <author>Jens Prager</author>
    <author>Marc Kreutzbruck</author>
    <author>Uwe Beck</author>
    <author>Thorid Lange</author>
    <author>Matthias Weise</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Thermo-acoustic</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Broadband airborne ultrasound</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Resonance-free ultrasound transducer</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>High pressure airborne ultrasound</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Sound particle velocity measurement</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Physisches Exemplar in der Bibliothek der BAM vorhanden ("Hardcopy Access")</collection>
  </doc>
  <doc>
    <id>27790</id>
    <completedYear/>
    <publishedYear>2013</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1541</pageFirst>
    <pageLast>1546</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>1511</volume>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation>American institute of physics (AIP)</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">A resonance-free nano-film airborne ultrasound emitter</title>
    <abstract language="eng">In this contribution we present a novel thermo-acoustic approach for the generation of broad band airborne ultrasound and investigate the applicability of resonance-free thermo-acoustic emitters for very short high pressure airborne ultrasound pulses. We report on measurements of thermo-acoustic emitter consisting of a 30 nm thin metallic film on a usual soda-lime glass substrate, generating sound pressure values of more than 140 dB at 60 mm distance from the transducer and compare the results with conventional piezoelectric airborne ultrasound transducers. Our experimental investigations show that such thermo-acoustic devices can be used as broad band emitters using pulse excitation.</abstract>
    <parentTitle language="eng">39th Annual review of progress in quantitative nondestructive evaluation (Proceedings)</parentTitle>
    <identifier type="old">30625</identifier>
    <identifier type="isbn">978-0-7354-1129-6</identifier>
    <identifier type="doi">10.1063/1.4789225</identifier>
    <identifier type="issn">0094-243X</identifier>
    <identifier type="issn">1551-7616</identifier>
    <note>Serientitel: AIP conference proceedings – Series title: AIP conference proceedings</note>
    <enrichment key="eventName">39th Annual review of progress in quantitative nondestructive evaluation</enrichment>
    <enrichment key="eventPlace">Denver, Colorado, USA</enrichment>
    <enrichment key="eventStart">15.07.2012</enrichment>
    <enrichment key="eventEnd">20.07.2012</enrichment>
    <enrichment key="date_peer_review">05.03.2013</enrichment>
    <author>Maxim Daschewski</author>
    <author>Andrea Harrer</author>
    <author>Jens Prager</author>
    <author>Marc Kreutzbruck</author>
    <author>Uwe Beck</author>
    <author>Thorid Lange</author>
    <author>Matthias Weise</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Thermo-acoustic</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Broad band airborne ultrasound</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>High pressure airborne ultrasound</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Resonance free ultrasound transducer</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Broad band ultrasonic emitter</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Measurement sound particle velocity</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>29277</id>
    <completedYear/>
    <publishedYear>2013</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>13</pageLast>
    <pageNumber/>
    <edition/>
    <issue>1</issue>
    <volume>32</volume>
    <type>article</type>
    <publisherName>Plenum Press</publisherName>
    <publisherPlace>New York, NY</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">SAFT and TOFD - A comparative study of two defect sizing techniques on a reactor pressure vessel mock-up</title>
    <abstract language="eng">Defect sizing is required for a quantitative assessment of the quality and reliability of safety relevant components and materials using ultrasonic non-destructive testing. The SAFT (Synthetic Aperture Focussing Technique) and the TOFD technique (Time Of Flight Diffraction) are such promising sizing candidates, extracting more information from the raw ultrasound echo data and the corresponding crack tip response. In this work the phased array technique is used to inspect a clad mock-up model of a pressure vessel section. The full scale model contains artificial test reflectors which are located in the weld and in the cladding region as well. The defects—representing typical flaws at a very early stage—are analysed with different frequencies, beam angles and directions of incidence.&#13;
&#13;
For the reconstruction of reflector indications a SAFT algorithm is applied to the phased array measurement results. Additionally the reflectors are analysed by means of the TOFD technique, using different beam angles at the same time. Both analysis methods are performed using different directions of incidence considering the complex cladding structure underneath the inner surface of the mock-up model. A direct comparison of the SAFT and TOFD techniques shows that, besides the clarity of the results, the detection and sizing capabilities of SAFT are far better.</abstract>
    <parentTitle language="eng">Journal of nondestructive evaluation</parentTitle>
    <identifier type="old">32188</identifier>
    <identifier type="doi">10.1007/s10921-012-0153-9</identifier>
    <identifier type="issn">0195-9298</identifier>
    <identifier type="issn">1573-4862</identifier>
    <enrichment key="date_peer_review">21.10.2013</enrichment>
    <author>Jens Prager</author>
    <author>Jessica Kitze</author>
    <author>Cécile Acheroy</author>
    <author>Daniel Brackrock</author>
    <author>Gerhard Brekow</author>
    <author>Marc Kreutzbruck</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic inspection</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Phased array probe</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Synthetic aperture focussing technique</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Time of flight diffraction method</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>29278</id>
    <completedYear/>
    <publishedYear>2013</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>114903-1 - 114903-12</pageFirst>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>114</volume>
    <type>article</type>
    <publisherName>American Institute of Physics</publisherName>
    <publisherPlace>Melville, NY</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Physics of thermo-acoustic sound generation</title>
    <abstract language="eng">We present a generalized analytical model of thermo-acoustic sound generation based on the analysis of thermally induced energy density fluctuations and their propagation into the adjacent matter. The model provides exact analytical prediction of the sound pressure generated in fluids and solids; consequently, it can be applied to arbitrary thermal power sources such as thermophones, plasma firings, laser beams, and chemical reactions. Unlike existing approaches, our description also includes acoustic near-field effects and sound-field attenuation. Analytical results are compared with measurements of sound pressures generated by thermo-acoustic transducers in air for frequencies up to 1 MHz. The tested transducers consist of titanium and indium tin oxide coatings on quartz glass and polycarbonate substrates. The model reveals that thermo-acoustic efficiency increases linearly with the supplied thermal power and quadratically with thermal excitation frequency. Comparison of the efficiency of our thermo-acoustic transducers with those of piezoelectric-based airborne ultrasound transducers using impulse excitation showed comparable sound pressure values. The present results show that thermo-acoustic transducers can be applied as broadband, non-resonant, high-performance ultrasound sources.</abstract>
    <parentTitle language="eng">Journal of applied physics</parentTitle>
    <identifier type="old">32189</identifier>
    <identifier type="doi">10.1063/1.4821121</identifier>
    <identifier type="issn">0021-8979</identifier>
    <identifier type="issn">1089-7550</identifier>
    <enrichment key="date_peer_review">21.10.2013</enrichment>
    <author>Maxim Daschewski</author>
    <author>Rainer Boehm</author>
    <author>Jens Prager</author>
    <author>Marc Kreutzbruck</author>
    <author>Andrea Harrer</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Thermophone</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ionophone</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Thermo-acoustic effect</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Non resonant ultrasound source</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>29733</id>
    <completedYear/>
    <publishedYear>2014</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>551</pageFirst>
    <pageLast>562</pageLast>
    <pageNumber/>
    <edition/>
    <issue>2</issue>
    <volume>54</volume>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace>Amsterdam</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Quantitative evaluation of ultrasonic C-scan image in acoustically homogeneous and layered anisotropic materials using three dimensional ray tracing method</title>
    <abstract language="eng">Quantitative evaluation of ultrasonic C-scan images in homogeneous and layered anisotropic austenitic materials is of general importance for understanding the influence of anisotropy on wave fields during ultrasonic non-destructive testing and evaluation of these materials. In this contribution, a three dimensional ray tracing method is presented for evaluating ultrasonic C-scan images quantitatively in general homogeneous and layered anisotropic austenitic materials. The directivity of the ultrasonic ray source in general homogeneous columnar grained anisotropic austenitic steel material (including layback orientation) is obtained in three dimensions based on Lamb's reciprocity theorem. As a prerequisite for ray tracing model, the problem of ultrasonic ray energy reflection and transmission coefficients at an interface between (a) isotropic base material and anisotropic austenitic weld material (including layback orientation), (b) two adjacent anisotropic weld metals and (c) anisotropic weld metal and isotropic base material is solved in three dimensions. The influence of columnar grain orientation and layback orientation on ultrasonic C-scan image is quantitatively analyzed in the context of ultrasonic testing of homogeneous and layered austenitic steel materials. The presented quantitative results provide valuable information during ultrasonic characterization of homogeneous and layered anisotropic austenitic steel materials.</abstract>
    <parentTitle language="eng">Ultrasonics</parentTitle>
    <identifier type="old">32665</identifier>
    <identifier type="doi">10.1016/j.ultras.2013.08.007</identifier>
    <identifier type="issn">0041-624x</identifier>
    <enrichment key="date_peer_review">11.12.2013</enrichment>
    <author>Sanjeevareddy Kolkoori</author>
    <author>Christian Höhne</author>
    <author>Jens Prager</author>
    <author>Michael Rethmeier</author>
    <author>Marc Kreutzbruck</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic non-destructive evaluation</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic C-scan image</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Anisotropic austenitic steel</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>3D ray tracing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Directivity</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>27324</id>
    <completedYear/>
    <publishedYear>2013</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>396</pageFirst>
    <pageLast>411</pageLast>
    <pageNumber/>
    <edition/>
    <issue>2</issue>
    <volume>53</volume>
    <type>article</type>
    <publisherName>Elsevier B.V.</publisherName>
    <publisherPlace>Amsterdam</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Ultrasonic field profile evaluation in acoustically inhomogeneous anisotropic materials using 2D ray tracing model: Numerical and experimental comparison</title>
    <abstract language="eng">Ultrasound propagation in inhomogeneous anisotropic materials is difficult to examine because of the directional dependency of elastic properties. Simulation tools play an important role in developing advanced reliable ultrasonic non destructive testing techniques for the inspection of anisotropic materials particularly austenitic cladded materials, austenitic welds and dissimilar welds. In this contribution we present an adapted 2D ray tracing model for evaluating ultrasonic wave fields quantitatively in inhomogeneous anisotropic materials. Inhomogeneity in the anisotropic material is represented by discretizing into several homogeneous layers. According to ray tracing model, ultrasonic ray paths are traced during its energy propagation through various discretized layers of the material and at each interface the problem of reflection and transmission is solved. The presented algorithm evaluates the transducer excited ultrasonic fields accurately by taking into account the directivity of the transducer, divergence of the ray bundle, density of rays and phase relations as well as transmission coefficients. The ray tracing model is able to calculate the ultrasonic wave fields generated by a point source as well as a finite dimension transducer. The ray tracing model results are validated quantitatively with the results obtained from 2D Elastodynamic Finite Integration Technique (EFIT) on several configurations generally occurring in the ultrasonic non destructive testing of anisotropic materials. Finally, the quantitative comparison of ray tracing model results with experiments on 32 mm thick austenitic weld material and 62 mm thick austenitic cladded material is discussed.</abstract>
    <parentTitle language="eng">Ultrasonics</parentTitle>
    <identifier type="old">30132</identifier>
    <identifier type="doi">10.1016/j.ultras.2012.07.006</identifier>
    <enrichment key="date_peer_review">10.12.2012</enrichment>
    <author>Sanjeevareddy Kolkoori</author>
    <author>Mehbub-Ur Rahman</author>
    <author>P.K. Chinta</author>
    <author>Marc Kreutzbruck</author>
    <author>Michael Rethmeier</author>
    <author>Jens Prager</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic field</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>2D ray tracing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Directivity</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Anisotropic austenitic weld</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Non-destructive testing</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>26205</id>
    <completedYear/>
    <publishedYear>2012</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1227</pageFirst>
    <pageLast>1234</pageLast>
    <pageNumber/>
    <edition/>
    <issue>1430</issue>
    <volume/>
    <type>conferenceobject</type>
    <publisherName>American Institute of Physics</publisherName>
    <publisherPlace>Melville, NY</publisherPlace>
    <creatingCorporation>Iowa State University</creatingCorporation>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Quantitative evaluation of ultrasonic sound fields in anisotropic austenitic welds using 2D ray tracing model</title>
    <abstract language="eng">Ultrasonic investigation of inhomogeneous anisotropic materials such as austenitic welds is complicated because its columnar grain structure leads to curved energy paths, beam splitting and asymmetrical beam profiles. A ray tracing model has potential advantage in analyzing the ultrasonic sound field propagation and there with optimizing the inspection parameters. In this contribution we present a 2D ray tracing model to predict energy ray paths, ray amplitudes and travel times for the three wave modes quasi longitudinal, quasi shear vertical, and shear horizontal waves in austenitic weld materials. Inhomogenity in the austenitic weld material is represented by discretizing the inhomogeneous region into several homogeneous layers. At each interface between the layers the reflection and transmission problem is computed and yields energy direction, amplitude and energy coefficients. The ray amplitudes are computed accurately by taking into account directivity, divergence and density of rays, phase relations as well as transmission coefficients. Ultrasonic sound fields obtained from the ray tracing model are compared quantitatively with the 2D Elastodynamic Finite Integration Technique (EFIT). The excellent agreement between both models confirms the validity of the presented ray tracing results. Experiments are conducted on austenitic weld samples with longitudinal beam transducer as transmitting probe and amplitudes at the rear surface are scanned by means of electrodynamical probes. Finally, the ray tracing model results are also validated through the experiments.</abstract>
    <parentTitle language="eng">Review of progress in quantitative nondestructive evaluation, volume 31</parentTitle>
    <identifier type="old">28952</identifier>
    <identifier type="isbn">978-0-7354-1013-8</identifier>
    <identifier type="doi">10.1063/1.4716359</identifier>
    <identifier type="issn">0743-0760</identifier>
    <identifier type="issn">0094-243X</identifier>
    <note>Serientitel: AIP conference proceedings – Series title: AIP conference proceedings</note>
    <enrichment key="eventName">38th Annual Review of Progress in Quantitative Nondestructive Evaluation</enrichment>
    <enrichment key="eventPlace">Burlington, VT, USA</enrichment>
    <enrichment key="eventStart">17.07.2011</enrichment>
    <enrichment key="eventEnd">22.07.2011</enrichment>
    <enrichment key="date_peer_review">02.08.2012</enrichment>
    <author>Sanjeevareddy Kolkoori</author>
    <author>Mehbub-Ur Rahman</author>
    <author>P.K. Chinta</author>
    <author>Marc Kreutzbruck</author>
    <author>Jens Prager</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ultrasonic sound field</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ray tracing</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ray directivity</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Austenitic weld</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>26737</id>
    <completedYear/>
    <publishedYear>2012</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>35</pageFirst>
    <pageLast>41</pageLast>
    <pageNumber/>
    <edition/>
    <issue>1-4</issue>
    <volume>39</volume>
    <type>article</type>
    <publisherName>IOS Press</publisherName>
    <publisherPlace>Amsterdam, The Netherlands</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>1</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Thermoacoustic generation of airborne ultrasound using carbon materials at the micro- and nanoscale</title>
    <abstract language="eng">The generation of airborne ultrasound is presented using the thermoacoustic principle applied to carbon materials at the micro- and nanoscale. Such materials are shown to be capable of emitting ultrasound when being fed by an alternating current. We tested the acoustic performance of carbon fibers, bucky papers and electrospun polyacrylonitrile-derived carbon nanofibers and determined the sound pressure for frequencies up to 350 kHz. A comparison between the experimental results and the theoretical prediction showed remarkable agreement for frequencies up to 150 kHz. Beyond 150 kHz, we found slight deviations from the expected sound pressure dependence on the square root of the frequency.</abstract>
    <parentTitle language="eng">International journal of applied electromagnetics and mechanics</parentTitle>
    <identifier type="old">29519</identifier>
    <identifier type="doi">10.3233/JAE-2012-1440</identifier>
    <identifier type="issn">1383-5416</identifier>
    <identifier type="issn">0925-2096</identifier>
    <enrichment key="date_peer_review">22.10.2012</enrichment>
    <author>Andrea Harrer</author>
    <author>Maxim Daschewski</author>
    <author>Jens Prager</author>
    <author>Marc Kreutzbruck</author>
    <author>Matthias Guderian</author>
    <author>Asmus Meyer-Plath</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Thermoacoustic</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Airborne ultrasound transducer</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Sound pressure</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
  <doc>
    <id>26350</id>
    <completedYear/>
    <publishedYear>2012</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>8 (Paper 497)</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Progress in acoustical defect sizing NDT methods for the inspection of power-plant components</title>
    <abstract language="eng">The demand of improved NDT methods with proper visualization and sizing capabilities is a persistent trend in maintenance and manufacturing quality inspection.&#13;
Especially when dealing with high quality standards in conjunction with safety-critical components in the sector of energy and transportation quantitative NDT techniques are vital to provide reliable quality control systems and a corresponding deeper insight into the component structure for a further fracture-mechanical estimation. The paper thus focuses the progress of the defect sizing capabilities of modern Ultrasonic Testing (UT). In Ultrasonic Testing the SAFT-algorithm (Synthetic Aperture Focusing Technique) currently experiences a renaissance. The method is based on combining the data of different transducer positions with their corresponding varied propagating time and it is currently applied in several industrial applications. SAFT enhances the SNR and the spatial resolution and is thus a valuable tool when it comes to improved defect detection and sizing. A tomographic-like data mapping is illustrated on several examples, where adapted phased array systems were used for the inspection of turbine components and also for a cladded mock-up of a nuclear reactor pressure vessel. In a statistical investigation we also performed a comparison with other defect sizing methods like TOFD (Time of flight diffraction).</abstract>
    <parentTitle language="eng">18th WCNDT - World conference on nondestructive testing (Proceedings)</parentTitle>
    <identifier type="old">29109</identifier>
    <identifier type="isbn">978-0-620-52872-6</identifier>
    <enrichment key="eventName">18th WCNDT - World conference on nondestructive testing</enrichment>
    <enrichment key="eventPlace">Durban, South Africa</enrichment>
    <enrichment key="eventStart">16.04.2012</enrichment>
    <enrichment key="eventEnd">20.04.2012</enrichment>
    <author>Marc Kreutzbruck</author>
    <author>Jens Prager</author>
    <author>Rainer Boehm</author>
    <author>Jessica Kitze</author>
    <author>Gerhard Brekow</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>SAFT</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>TOFD</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Cracks</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Phased Array</value>
    </subject>
    <collection role="literaturgattung" number="">Verlagsliteratur</collection>
    <collection role="fulltextaccess" number="">Datei im Netzwerk der BAM verfügbar ("Closed Access")</collection>
  </doc>
</export-example>
