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  <doc>
    <id>3993</id>
    <completedYear/>
    <publishedYear>2022</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>26</volume>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2022-05-18</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">An Algorithmic Approach to Compute the Effect of Non-Radiative Relaxation Processes in Photoacoustic Spectroscopy</title>
    <abstract language="eng">Successful transfer of photoacoustic gas sensors from laboratory to real-life applications requires knowledge about potential cross-sensitivities towards environmental and gas matrix changes. Multi-dimensional calibration in case of cross-sensitivities can become very complex or even unfeasible. To address this challenge, we present a novel algorithm to compute the collision based non-radiative efficiency and phase lag of energy relaxation on a molecular level (CoNRad) for photoacoustic signal calculation. This algorithmic approach allows to calculate the entire elaxation cascade of arbitrarily complex systems, yielding a theoretical photoacoustic signal. In this work the influence of varying bulk compositions, i.e. nitrogen (N2), oxygen (O2) and water (H2O) on the photoacoustic signal during methane (CH4) detection is demonstrated. The applicability of the algorithm to other photoacoustic setups is shown exemplary by applying it to the relaxational system investigated in [1]. Hayden et al. examined the effect of water on photoacoustic carbon monoxide (CO) detection.</abstract>
    <parentTitle language="deu">Photoacoustics</parentTitle>
    <identifier type="doi">10.1016/j.pacs.2022.100371</identifier>
    <identifier type="urn">urn:nbn:de:bvb:898-opus4-39935</identifier>
    <note>Corresponding author: Max Müller</note>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="CorrespondingAuthor">Müller, Max</enrichment>
    <enrichment key="AmountAPC">1.820 EUR</enrichment>
    <enrichment key="BegutachtungStatus">peer-reviewed</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Max Müller</author>
    <author>Thomas Rück</author>
    <author>Simon Jobst</author>
    <author>Jonas Pangerl</author>
    <author>Stefan Weigl</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="oaweg" number="">Gold Open Access- Erstveröffentlichung in einem/als Open-Access-Medium</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="oaweg" number="">Corresponding author der OTH Regensburg</collection>
    <collection role="funding" number="">Projektmittel</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
    <thesisPublisher>Ostbayerische Technische Hochschule Regensburg</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-oth-regensburg/files/3993/Mueller_Photoacoustics.pdf</file>
  </doc>
  <doc>
    <id>1568</id>
    <completedYear/>
    <publishedYear>2013</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferencepresentation</type>
    <publisherName/>
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    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2021-03-21</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">A Conductivity Probe for Determination of the Carbon Dioxide Tension at the Oxygenator Exhaust Outlet during Extracorporeal Membrane Oxygenation (ECMO)</title>
    <parentTitle language="eng">Proceedings of the 9th ISC Modern Analytical Chemistry 2013, Prag</parentTitle>
    <identifier type="url">https://www.gdch.de/fileadmin/downloads/Veranstaltungen/Tagungen/2014_Tagungen/analytica/poster_abstracts/sens03_vanderweerd_5860.pdf</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <author>Bastiaan van der Weerd</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>1561</id>
    <completedYear/>
    <publishedYear>2014</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferencepresentation</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2021-03-21</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Development of a miniaturized photoacoustic multigas sensing system for trace gas measurement</title>
    <parentTitle language="eng">analytica conference 2014, 1. bis 4. April, München</parentTitle>
    <identifier type="url">https://www.gdch.de/fileadmin/downloads/Veranstaltungen/Tagungen/2014_Tagungen/analytica/poster_abstracts/sens05_rueck_5925.pdf</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <author>Thomas Rück</author>
    <author>Frank-Michael Matysik</author>
    <author>Rudolf Bierl</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>1452</id>
    <completedYear/>
    <publishedYear>2015</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferencepresentation</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2015-03-26</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Comparison of acoustic detectors for use in miniaturized photoacoustic devices designed for nitrogen dioxide trace gas measurement</title>
    <parentTitle language="deu">ANAKON, 23.-26.3.2015, Graz</parentTitle>
    <enrichment key="opus.source">publish</enrichment>
    <author>Thomas Rück</author>
    <author>Frank-Michael Matysik</author>
    <author>Rudolf Bierl</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>7127</id>
    <completedYear/>
    <publishedYear>2024</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber>12</pageNumber>
    <edition/>
    <issue/>
    <volume>38</volume>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">An inexpensive UV-LED photoacoustic based real-time sensor-system detecting exhaled trace-acetone</title>
    <abstract language="eng">n this research we present a low-cost system for breath acetone analysis based on UV-LED photoacoustic spectroscopy. We considered the end-tidal phase of exhalation, which represents the systemic concentrations of volatile organic compounds (VOCs) – providing clinically relevant information about the human health. This is achieved via the development of a CO2-triggered breath sampling system, which collected alveolar breath over several minutes in sterile and inert containers. A real-time mass spectrometer is coupled to serve as a reference device for calibration measurements and subsequent breath analysis. The new sensor system provided a 3σ detection limit of 8.3 ppbV and an NNEA of 1.4E-9 Wcm 1Hz 0.5. In terms of the performed breath analysis measurements, 12 out of 13 fell within the error margin of the photoacoustic measurement system, demonstrating the reliability of the measurements in the field.</abstract>
    <parentTitle language="eng">Photoacoustics</parentTitle>
    <identifier type="issn">2213-5979</identifier>
    <identifier type="doi">10.1016/j.pacs.2024.100604</identifier>
    <identifier type="urn">urn:nbn:de:bvb:898-opus4-71279</identifier>
    <note>Corresponding author der OTH Regensburg: Jonas Pangerl</note>
    <enrichment key="BegutachtungStatus">peer-reviewed</enrichment>
    <enrichment key="CorrespondingAuthor">Jonas Pangerl</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Jonas Pangerl</author>
    <author>Pritam Sukul</author>
    <author>Thomas Rück</author>
    <author>Patricia Fuchs</author>
    <author>Stefan Weigl</author>
    <author>Wolfram Miekisch</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Photoacoustic spectroscopy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Real-time mass-spectrometry</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Breath analysis</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Acetone</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>UV-LED</value>
    </subject>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="oaweg" number="">Gold Open Access- Erstveröffentlichung in einem/als Open-Access-Medium</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="oaweg" number="">Corresponding author der OTH Regensburg</collection>
    <collection role="funding" number="">Publikationsfonds der OTH Regensburg</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
    <thesisPublisher>Ostbayerische Technische Hochschule Regensburg</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-oth-regensburg/files/7127/Pangerl_Photoacoustics_2024.pdf</file>
  </doc>
  <doc>
    <id>8007</id>
    <completedYear/>
    <publishedYear>2025</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber>16</pageNumber>
    <edition/>
    <issue/>
    <volume>43</volume>
    <type>article</type>
    <publisherName>Elsevier BV</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Photodissociation-Driven Photoacoustic Spectroscopy with UV-LEDs for Ozone Detection</title>
    <abstract language="eng">This study presents the development and evaluation of a UV-LED based photoacoustic (PA) measurement system for ozone (O3) detection to demonstrate its potential for low-cost and accurate sensing while for the first time addressing the importance of photodissociation for PA signal generation for O3 in the UV range. With a detection limit of 7.9 ppbV, the system exhibits a significant advancement over state-of-the-art UV-PA O3 detection and is on par with laser-based setups. Following a novel discussion of the PA signal arising from photodissociation and its products, cross-sensitivity effects due to environmental factors such as temperature and gas composition were systematically analyzed. A digital twin driven compensation for these influences was implemented and evaluated. Despite the challenges associated with modeling the effects of H2O and CO2, the PA system shows considerable potential, though further studies in real world applications must be conducted.</abstract>
    <parentTitle language="eng">Photoacoustics</parentTitle>
    <identifier type="issn">2213-5979</identifier>
    <identifier type="doi">10.1016/j.pacs.2025.100718</identifier>
    <identifier type="urn">urn:nbn:de:bvb:898-opus4-80076</identifier>
    <note>Corresponding author der OTH Regensburg: Lukas Escher</note>
    <enrichment key="BegutachtungStatus">peer-reviewed</enrichment>
    <enrichment key="opus.source">doi-import</enrichment>
    <enrichment key="CorrespondingAuthor">Lukas Escher</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Lukas Escher</author>
    <author>Thomas Rück</author>
    <author>Simon Jobst</author>
    <author>Jonas Pangerl</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Photoacoustic spectroscopy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>UV-LED</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Ozone</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Photodissociation</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Cross-sensitivity</value>
    </subject>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="oaweg" number="">Hybrid Open Access - OA-Veröffentlichung in einer Subskriptionszeitschrift/-medium</collection>
    <collection role="oaweg" number="">Corresponding author der OTH Regensburg</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
    <collection role="funding" number="">DEAL Elsevier</collection>
    <collection role="DFGFachsystematik" number="1">Ingenieurwissenschaften</collection>
    <thesisPublisher>Ostbayerische Technische Hochschule Regensburg</thesisPublisher>
    <file>https://opus4.kobv.de/opus4-oth-regensburg/files/8007/escher_photoacoustics_2025.pdf</file>
  </doc>
  <doc>
    <id>845</id>
    <completedYear/>
    <publishedYear>2020</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>1</pageFirst>
    <pageLast>11</pageLast>
    <pageNumber/>
    <edition/>
    <issue>August</issue>
    <volume>316</volume>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2020-08-01</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Photoacoustic detection of acetone in N2 and synthetic air using a high power UV LED</title>
    <abstract language="eng">The performance of a photoacoustic trace gas sensor for the detection of acetone in N2 and synthetic air is reported. The sensor system utilises an amplitude modulated UV LED. The light source has an emission maximum at 278 nm and a maximum CW output power of 300 mW according to the datasheet. Three different collimating and focusing approaches have been investigated to guide the highly divergent LED light into the acoustic resonator of the photoacoustic measurement cell. A 3D printed aluminium cell was designed to optimize light coupling by simultaneously minimizing the photoacoustic background signal generation. Hence, the diameter of the resonator was set to a comparable large diameter of 10 mm and the inner walls of the resonator were mirror polished. The additive manufacturing procedure allowed for integration of a spirally formed gas channel, enabling gas heating prior to detection. The sensor performance was investigated by measuring acetone in N2 and synthetic air at different concentrations. The UV LED current was set to 86 % of the maximum value according to the datasheet of the light source in order to increase the lifetime and thermal stability. An Allan-Werle deviation analysis validates a stable sensor performance. The limit of detection (LoD) was determined at a 3σ noise level with a 10 s lock-in amplifier time constant by sampling data points over 20 s with a data acquisition rate of 5 Hz. LoDs of 80.8 ppbV and 19.6 ppbV were obtained for acetone in N2 and synthetic air, respectively.</abstract>
    <parentTitle language="eng">Sensors Actuators B Chemical</parentTitle>
    <identifier type="doi">10.1016/j.snb.2020.128109</identifier>
    <note>Corresponding author at: Sensorik-Applikationszentrum (SappZ) der Ostbayerischen Technischen Hochschule Regensburg</note>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="BegutachtungStatus">peer-reviewed</enrichment>
    <licence>Creative Commons - CC BY-NC-ND - Namensnennung - Nicht kommerziell - Keine Bearbeitungen 4.0 International</licence>
    <author>Stefan Weigl</author>
    <author>Florian Feldmeier</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Acetone detection</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Photoacoustic spectroscopy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>High power UV LED</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>UV LED collimation system</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Acetone breath analysis</value>
    </subject>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="oaweg" number="">Hybrid Open Access - OA-Veröffentlichung in einer Subskriptionszeitschrift/-medium</collection>
    <collection role="oaweg" number="">Corresponding author der OTH Regensburg</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>843</id>
    <completedYear/>
    <publishedYear>2021</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue>328</issue>
    <volume/>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2020-10-04</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Effects of ambient parameters and cross-sensitivities from O2, CO2 and H2O on the photoacoustic detection of acetone in the UV region</title>
    <abstract language="eng">We present a sensitive UV LED photoacoustic setup for the detection of gaseous acetone and discuss its applicability towards breath analysis. We investigated the performance of the sensor for low acetone concentrations down to 0.1 parts per million (ppmV). The influences of temperature, flow, pressure, optical power and LED duty cycle on the measured signal have been examined. To gain a better understanding of the different effects on the photoacoustic signal, correlation analysis was applied and feature importance was determined using a large measured dataset. Furthermore, the cross-sensitivities towards O2, CO2 and H2O have been studied extensively. Finally, the sensor’s performance to detect acetone between 0.1–1 ppmV within gas mixtures simulating breath exhale conditions has been investigated, too. With a limit of detection (LoD) of 12.5 parts per billion (ppbV) (3σ) measured under typical breath exhale gas mixture conditions, the sensor demonstrated a high potential for the application of acetone detection in human breath analysis.</abstract>
    <parentTitle language="eng">Sensors Actuators B Chemical</parentTitle>
    <identifier type="doi">10.1016/j.snb.2020.129001</identifier>
    <identifier type="issn">0925-4005</identifier>
    <note>Corresponding authors: Stefan Weigl, Elisabeth Wittmann, Thomas Rück, Rudolf Bierl, Frank-Michael Matysik</note>
    <note>Corrigendum to “Effects of ambient parameters and cross-sensitivities from O2, CO2 and H2O on the photoacoustic detection of acetone in the UV region” [Sens. Actuators B: Chem. 328 (February 2021) (2020) 129001]; https://doi.org/10.1016/j.snb.2020.129392</note>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="BegutachtungStatus">peer-reviewed</enrichment>
    <licence>Creative Commons - CC BY-NC-ND - Namensnennung - Nicht kommerziell - Keine Bearbeitungen 4.0 International</licence>
    <author>Stefan Weigl</author>
    <author>Elisabeth Wittmann</author>
    <author>Thomas Rück</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Acetone detection</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Photoacoustic spectroscopy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>High power UV LED</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Cross-sensitivities</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Acetone breath analysis</value>
    </subject>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="oaweg" number="">Hybrid Open Access - OA-Veröffentlichung in einer Subskriptionszeitschrift/-medium</collection>
    <collection role="oaweg" number="">Corresponding author der OTH Regensburg</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>7065</id>
    <completedYear/>
    <publishedYear>2024</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>preprint</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">An Inexpensive Uv-Led Photoacoustic Based Real-Time Sensor-System Detecting Exhaled Trace-Acetone</title>
    <abstract language="eng">In this research we present a low-cost system for breath acetone analysis based on UV-LED photoacoustic spectroscopy. We considered the end-tidal phase of exhalation, which represents the systemic concentrations of volatile organic compounds (VOCs) – providing clinically relevant information about the human health. This is achieved via the development of a CO2-triggered breath sampling system, which collected alveolar breath over several minutes in sterile and inert containers. A real-time mass spectrometer is coupled to serve as a reference device for calibration measurements and subsequent breath analysis. The new sensor system provided a 3σ detection limit of 6.4 ppbV and an NNEA of 1.1E-9 Wcm-1Hz-0.5. In terms of the performed breath analysis measurements, 12 out of 13 fell within the error margin of the photoacoustic measurement system, demonstrating the reliability of the measurements in the field.</abstract>
    <identifier type="doi">10.2139/ssrn.4724198</identifier>
    <note>Der Aufsatz wurde peer-reviewed unter folgender DOI veröffentlicht: https://doi.org/10.1016/j.pacs.2024.100604</note>
    <licence>Keine Lizenz - Es gilt das deutsche Urheberrecht: § 53 UrhG</licence>
    <author>Jonas Pangerl</author>
    <author>Pritam Sukul</author>
    <author>Thomas Rück</author>
    <author>Patricia Fuchs</author>
    <author>Stefan Weigl</author>
    <author>Wolfram Miekisch</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>photoacoustic spectroscopy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>real-time mass-spectrometry</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>breath analysis</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>acetone</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>UV-LED</value>
    </subject>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>1431</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>2462</pageFirst>
    <pageLast>2471</pageLast>
    <pageNumber/>
    <edition/>
    <issue>Part 3, February</issue>
    <volume>255</volume>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">NO2 trace gas monitoring in air using off-beam quartz enhanced photoacoustic spectroscopy (QEPAS) and interference studies towards CO2, H2O and acoustic noise</title>
    <abstract language="eng">We present the development and characterization as well as comprehensive interference studies of a photoacoustic NO2 trace gas detection system. The system is based on an off-beam quartz enhanced photoacoustic scheme (off-beam QEPAS) and signal generation was initiated by amplitude modulating a low-cost diode laser emitting at 450 nm. The QEPAS sensor element features double-resonant amplification, still it is only ∼ 5 × 5 × 2.5 mm in size. The individual and combined resonance characteristics were investigated and specified to 52 dB amplification, adding up 15 dB acoustic- and 37 dB mechanical-resonance amplification. The linearity of the photoacoustic signal dependency on the analyte concentration was verified from 200 ppbV to 100 ppmV NO2 in synthetic air. The detection limit (3σ) was determined to 1.8 ppbV using a lock-in time constant of 10 s and an averaging time of 20 s. The normalized noise equivalent absorption coefficient was specified to 2.5·10−8 W cm−1 Hz−0.5. The stability of the signal was investigated over time and a slight drift by 1‰ was observed after 30 min without temperature stabilizing the photoacoustic cell (PAC). Noise analysis was performed by means of Allan deviation and the inverse dependency of response time and precision of the system on the lock-in time constant was outlined. We performed interference analyses towards N2, O2, CO2, H2O and acoustic noise, respectively. Although neither spectral interferences nor losses due to slow NO2 VT-relaxation were observed, O2 was identified to cause a 15% signal drop due to VVNO2-O2-relaxation. Changing H2O concentrations were found to cause acoustic detuning, which cannot be compensated by adjusting the frequency of modulation, because of the double-resonant feature of the PAC. However, alternative approaches of compensation were discussed. Finally, we carried out heavy traffic noise simulations and determined the QEPAS setup to be 46 times less susceptible towards ambient noise compared to standard microphone-based photoacoustic setups.</abstract>
    <parentTitle language="eng">Sensors and Actuators B: Chemical</parentTitle>
    <identifier type="doi">10.1016/j.snb.2017.09.039</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="BegutachtungStatus">peer-reviewed</enrichment>
    <author>Thomas Rück</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>1432</id>
    <completedYear/>
    <publishedYear>2017</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>193</pageFirst>
    <pageLast>200</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>258</volume>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace>Amsterdam, Niederlande</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2017-05-01</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Development and characterization of a laboratory setup for photoacoustic NO2 determination based on the excitation of electronic 2B2 and 2B1 states using a low-cost semiconductor laser</title>
    <abstract language="eng">This work gives a detailed characterization of a laboratory setup for photoacoustic NO2 trace gas detection at the ppb level. The signal generation is based on the excitation of electronic 2B2 and 2B1 states using a low-cost semiconductor laser emitting at 450 nm. An acoustic resonator was used for signal amplification and the modulation frequency of the laser was determined to 3395 Hz in order to gain maximum signal amplification. The quality of resonant amplification was determined to 7.9. The gas samples were NO2 calibration gases diluted with pure nitrogen. The signal-to-noise ratio (SNR) dependency on the flow rate Q and the lock-in time constant τLIA was investigated, respectively, and the optimum values were specified to Q = 500 mL/min and τLIA = 2 s. In case of ambient noise, increasing τLIA to 10 s was evaluated as sufficient for SNR preservation. The noise level was measured in the absence of NO2 and it was determined to be composed of 51% electronic noise and 49% gas flow noise. With the analyte concentration ranging from 300 ppbV to 100 ppmV, the linear dependency of the photoacoustic amplitude on the NO2 concentration was specified, the sensitivity was determined to 110 μV/ppmV and the maximum measurement error was calculated to ±0.8%. The detection limit was determined to 2.0 ppbV. Furthermore, the stability of the signal was investigated and a maximum drift of ±1% was observed within a measuring period of 30 min. The response time τ90 was specified to 58 s. All results considered, this photoacoustic measuring system, which is based on low-cost signal generation and detection units, provides an excellent basis in view of developing a portable device for photoacoustic trace gas detection.</abstract>
    <parentTitle language="eng">Sensors and Actuators A: Physical</parentTitle>
    <identifier type="doi">10.1016/j.sna.2017.03.024</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="BegutachtungStatus">peer-reviewed</enrichment>
    <author>Thomas Rück</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>1433</id>
    <completedYear/>
    <publishedYear>2017</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>501</pageFirst>
    <pageLast>509</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>263</volume>
    <type>article</type>
    <publisherName>Elsevier</publisherName>
    <publisherPlace>Amsterdam, Niederlande</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>2017-08-15</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Low-cost photoacoustic NO2 trace gas monitoring at the pptV-level</title>
    <abstract language="eng">We present the development and the characterization of a photoacoustic NO2 trace gas detection system. The system is based on the implementation of low-cost components, i.e. a mass-produced blue diode laser and a standard MEMS microphone which is commonly built into smartphones, for example. An optimized cell design was realized by means of 3D printing. The linearity of the photoacoustic signal dependency on the analyte concentration was verified from 200 ppbV to 100 ppmV NO2. The detection limit (1σ) was determined to 33 pptV and the normalized noise equivalent absorption coefficient was calculated to 7.0 ∙ 10−10 W cm−1 Hz−1/2. The dynamic range of the system was verified to be linear over three magnitudes of order and the sensitivity was calculated to 814 μV/ppmV. The system was characterized in view of optimal operating parameters, i.e. lock-in time constant τLIA and total mass flow rate, optical performance and signal stability. The mass flow dependend response time of the system was specified to 19 s and an idealized step response to a quasi-Heaviside step function was quantified as a function of τLIA. The quality factor of acoustic resonance was determined to 21.9 and an empirical expression regarding acoustic node shifting is provided. The expression takes into account the radius of the resonator pipe and the radius of the hole, which was drilled into the pipe for microphone coupling. Furthermore, we studied the cross-sensitivity of the photoacoustic signal towards H2O and CO2, respectively.</abstract>
    <parentTitle language="eng">Sensors and Actuators A: Physical</parentTitle>
    <identifier type="doi">10.1016/j.sna.2017.06.036</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="BegutachtungStatus">peer-reviewed</enrichment>
    <author>Thomas Rück</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>1430</id>
    <completedYear/>
    <publishedYear>2018</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferencesummary</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2018-09-01</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Development of a sensor system for analysis of human breath exhale</title>
    <abstract language="deu">Atemgasanalyse ist ein junges und vielversprechendes Feld im Bereich der diagnostischen Medizin. Der Ansatz verspricht einfach zugängliche und leicht wiederholbare Probennahme die zum einen non-invasiv ist und zugleich Rückschlüsse auf Vorgänge im menschlichen Körper und bspw. dessen Gesundheitszustand zulässt. Seit Ende des 20. Jahrhunderts gibt es Massenspektrometer die es ermöglicht haben mehrere Tausend verschiedene Stoffe in der Ausatemluft nachzuweisen. Diese Technologien verbessern sich stetig und ermöglichen es die Vorgänge und Zusammenhänge zwischen Zusammensetzung der Ausatemluft und systemischen Prozessen besser zu verstehen. Die bei Studien mit Massenspektrometern ermittelten Biomarker, deren qualitative und quantitative Detektion Gesundheitsdiagnosen ermöglichen, haben aber noch nicht den Weg in den klinischen Alltag gefunden. Das Problem sind meistens die hohen Anschaffungskosten, komplizierte Datenauswertung und zumeist geringe Verfügbarkeit und Immobilität dieser Messgeräte. Die photoakustische Spektroskopie ist eine selektive und hochsensitive Messmethode, die es ermöglichen soll den Biomarker „Aceton“, der grundsätzlich die Metabolisierung von Fetten widerspiegelt, schnell und reproduzierbar quantitativ zu detektieren. Dabei müssen Hindernisse wie Querempfindlichkeiten, ausgelöst durch die komplexe Zusammensetzung der Messmatrix Atemgas, bei gleichzeitig kleine Aceton Konzentrationen (200-800 parts-per-billion) überwunden werden. Verschiedene Wellenlängenbereiche mit unterschiedlichen Lichtquellen, akustisch resonante sowie innovative Messzellendesigns und anspruchsvolle Datenauswertung mittels komplexer Algorithmik sind nötig um das Ziel, die Entwicklung eines kompakten, günstigen und zuverlässigen Acetonsensors, zu erreichen.</abstract>
    <parentTitle language="deu">BayWISS Herbstakademie 2018, Plankstetten</parentTitle>
    <enrichment key="opus.source">publish</enrichment>
    <author>Stefan Weigl</author>
    <author>Frank-Michael Matysik</author>
    <author>Rudolf Bierl</author>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>1448</id>
    <completedYear/>
    <publishedYear>2016</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>263</pageFirst>
    <pageLast>280</pageLast>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume>6</volume>
    <type>article</type>
    <publisherName>Springer</publisherName>
    <publisherPlace>Berlin</publisherPlace>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2016-06-28</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Trends in Electrochemical Sensing of Blood Gases</title>
    <abstract language="eng">The monitoring of partial pressures of the blood gases carbon dioxide (pCO2) and oxygen (pO2) is of great importance in clinical diagnostics. The measure of pCO2 and pO2 provides essential information about the patient’s metabolism, gas exchange, ventilation, and acid–base homeostasis. The conventional electrochemical methods for clinical blood gas analysis are based on the potentiometric Severinghaus sensor for carbon dioxide and the amperometric Clark sensor for oxygen. These techniques are well established and are only shortly discussed in this overview. However, in recent years a variety of modifications of these classical sensor concepts and new approaches of electrochemical sensing of pCO2 and pO2 have been introduced. This review summarizes recent developments in this field and discusses the potential for future applications in clinical blood gas analysis.</abstract>
    <parentTitle language="eng">Bioanalytical Reviews</parentTitle>
    <identifier type="doi">10.1007/11663_2016_1</identifier>
    <enrichment key="OtherSeries">Trends in Bioelectroanalysis</enrichment>
    <author>Bastiaan van der Weerd</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Blood gas analysis</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Noninvasive blood gas sensor</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Electrochemical sensor</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Clinical analysis</value>
    </subject>
    <collection role="ddc" number="621">Angewandte Physik</collection>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>1559</id>
    <completedYear/>
    <publishedYear>2015</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2021-03-21</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Specification of an improved photoacoustic setup for high-sensitive, low-cost NO2 trace gas detection</title>
    <parentTitle language="eng">18th International Conference on Photoacoustic and Photothermal Phenomena (ICPPP18), 2015, September 6-10, Novi Sad, Serbia</parentTitle>
    <enrichment key="opus.source">publish</enrichment>
    <author>Thomas Rück</author>
    <author>Ferdinand Landgraf</author>
    <author>I. Läpple</author>
    <author>J. Unger</author>
    <author>Frank-Michael Matysik</author>
    <author>Rudolf Bierl</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>1565</id>
    <completedYear/>
    <publishedYear>2014</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2021-03-21</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">A Conductivity Probe for the Determination of Carbon Dioxide Tension at the Oxygenator Exhaust Outlet during Extracorporeal Membrane Oxygenation (ECMO)</title>
    <parentTitle language="eng">analytica Conference 2014, 1. bis 4. April, München</parentTitle>
    <enrichment key="opus.source">publish</enrichment>
    <author>Bastiaan van der Weerd</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>1566</id>
    <completedYear/>
    <publishedYear>2014</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2021-03-21</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">A Conductivity Probe for the Determination of Carbon Dioxide Tension at the Oxygenator Exhaust Outlet during Extracorporeal Membrane Oxygenation (ECMO)</title>
    <parentTitle language="eng">Electrochemistry 2014, September 22 - 24, Mainz</parentTitle>
    <enrichment key="opus.source">publish</enrichment>
    <author>Bastiaan van der Weerd</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>1564</id>
    <completedYear/>
    <publishedYear>2014</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2021-03-21</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">A Planar Conductivity Probe for CO2 Determination at the Oxygenator Outlet</title>
    <parentTitle language="deu">Doktorandenseminar GDCh Prozessanalytik 2014, Berlin</parentTitle>
    <enrichment key="opus.source">publish</enrichment>
    <author>Bastiaan van der Weerd</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>5417</id>
    <completedYear/>
    <publishedYear>2022</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber>22</pageNumber>
    <edition/>
    <issue/>
    <volume/>
    <type>preprint</type>
    <publisherName>Elsevier / SSRN</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Digital Twin of a Photoacoustic Trace Gas Sensor for Monitoring Methane in Complex Gas Compositions</title>
    <abstract language="eng">The digitalization of industrial processes requires smart sensor systems. Photoacoustic spectroscopy is well suited for this purpose as it allows for small-sized and low-cost trace gas analysis. However, the method is susceptible to changes in measurement conditions and standard calibration routines often fail to correct for all changes. We therefore created a Digital Twin (DT) of a photoacoustic trace gas sensor for methane and evaluated it regarding variations in gas composition (CH4, N2, O2, CO2, H2O), temperature and pressure. With a mean absolute percentage error of 0.8 % the accuracy of the sensor after DT compensation significantly exceeds the 24 % achieved based on standard calibration in nitrogen. For the first time, we can fully analytically compute the photoacoustic signal under moderate ambient conditions with an error in the ppbV range by taking a holistic approach. Assuming knowledge of the underlying energy transfer processes, the model of this Digital Twin can be adapted to any microphone based photoacoustic sensor for monitoring any analyte species.</abstract>
    <identifier type="doi">10.2139/ssrn.4215170</identifier>
    <licence>Keine Lizenz - Es gilt das deutsche Urheberrecht: § 53 UrhG</licence>
    <author>Thomas Rück</author>
    <author>Max Müller</author>
    <author>Simon Jobst</author>
    <author>Stefan Weigl</author>
    <author>Jonas Pangerl</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="oaweg" number="">Diamond Open Access - OA-Veröffentlichung ohne Publikationskosten (Sponsoring)</collection>
  </doc>
  <doc>
    <id>5442</id>
    <completedYear/>
    <publishedYear>2022</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName>Optica Publishing Group</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Creating a Digital Twin of a Photoacoustic Gas Sensor for Methane Detection in Complex Gas Matrices</title>
    <abstract language="deu">We present the calculation results from a digital twin (DT) of our photoacoustic (PA) sensor for methane detection, regarding gas composition, temperature and pressure variations.</abstract>
    <parentTitle language="eng">Proceedings Optical Sensors and Sensing Congress 2022 (AIS, LACSEA, Sensors, ES): 11–15 July 2022, Vancouver, British Columbia, Canada</parentTitle>
    <identifier type="doi">10.1364/LACSEA.2022.LW4D.2</identifier>
    <identifier type="isbn">978-1-957171-10-4</identifier>
    <enrichment key="OtherSeries">Technical Digest Series (Optica Publishing Group, 2022), paper LW4D.2.</enrichment>
    <licence>Keine Lizenz - Es gilt das deutsche Urheberrecht: § 53 UrhG</licence>
    <author>Max Müller</author>
    <author>Thomas Rück</author>
    <author>Simon Jobst</author>
    <author>Jonas Pangerl</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>6077</id>
    <completedYear/>
    <publishedYear>2023</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>preprint</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Ambient methane monitoring at Hohenpeißenberg utilizing photoacoustic spectroscopy and cavity ring down spectroscopy</title>
    <abstract language="eng">With an atmospheric concentration of approximately 2000 parts per billion (ppbV, 10−9) methane (CH4) is the second most abundant greenhouse gas (GHG) in the atmosphere after carbon dioxide (CO2). The task of long-term and spatially resolved GHG monitoring to verify whether climate policy actions are effective, is becoming more crucial as climate change progresses. In this paper we report the CH4 concentration readings of our photoacoustic (PA) sensor over a five day period at Hohenpeißenberg, Germany. As a reference device a calibrated cavity ringdown spectrometer Picarro G2301 from the meteorological observatory was employed. Trace gas measurements with photoacoustic instruments promise to provide low detection limits at comparably low costs. However, PA devices are often susceptible to cross-sensitivities related to environmental influences. The obtained results show that relaxation effects due to fluctuating environmental conditions, e.g. ambient humidity, are a non-negligible factor in PA sensor systems. Applying algorithm compensation techniques, which are capable of calculating the influence of relaxational effects on the photoacoustic signal, increase the accuracy of the photoacoustic sensor significantly. With an average relative deviation of 1.11 % from the G2301, the photoacoustic sensor shows good agreement with the reference instrument.</abstract>
    <identifier type="doi">10.5194/egusphere-2023-1010</identifier>
    <enrichment key="CorrespondingAuthor">Max Müller</enrichment>
    <licence>Creative Commons - CC BY - Namensnennung 4.0 International</licence>
    <author>Max Müller</author>
    <author>Stefan Weigl</author>
    <author>Jennifer Müller-Williams</author>
    <author>Matthias Lindauer</author>
    <author>Thomas Rück</author>
    <author>Simon Jobst</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>5933</id>
    <completedYear/>
    <publishedYear>2023</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue>378</issue>
    <volume/>
    <type>article</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Digital Twin of a Photoacoustic Trace Gas Sensor for Monitoring Methane in Complex Gas Compositions</title>
    <abstract language="eng">The digitalization of industrial processes requires smart sensor systems. Photoacoustic spectroscopy is well suited for this purpose as it allows for small-sized and low-cost trace gas analysis. However, the method is susceptible to changes in measurement conditions and standard calibration routines often fail to correct for all changes. We therefore created a Digital Twin (DT) of a photoacoustic trace gas sensor for methane and evaluated it regarding variations in gas composition (CH4, N2, O2, CO2, H2O), temperature and pressure. With a mean absolute percentage error of 0.8 % the accuracy of the sensor after DT compensation significantly exceeds the 24 % achieved based on standard calibration in nitrogen. For the first time, we can fully analytically compute the photoacoustic signal under moderate ambient conditions with an error in the ppbV range by taking a holistic approach. Assuming knowledge of the underlying energy transfer processes, the model of this Digital Twin can be adapted to any microphone based photoacoustic sensor for monitoring any analyte species.</abstract>
    <parentTitle language="deu">Sensors and Actuators B: Chemical</parentTitle>
    <identifier type="doi">10.1016/j.snb.2022.133119</identifier>
    <note>Preprint unter: https://doi.org/10.2139/ssrn.4215170 ; https://opus4.kobv.de/opus4-oth-regensburg/frontdoor/index/index/docId/5417</note>
    <enrichment key="BegutachtungStatus">peer-reviewed</enrichment>
    <licence>Keine Lizenz - Es gilt das deutsche Urheberrecht: § 53 UrhG</licence>
    <author>Thomas Rück</author>
    <author>Max Müller</author>
    <author>Simon Jobst</author>
    <author>Stefan Weigl</author>
    <author>Jonas Pangerl</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Digital Twin</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Photoacoustic spectroscopy</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Smart sensor</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Acoustic resonance monitoring</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>CoNRad</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>Calibration-free method</value>
    </subject>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>6538</id>
    <completedYear/>
    <publishedYear>2023</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>conferenceobject</type>
    <publisherName>Optica Publishing Group</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Using a Modulated Quantum Cascade Laser for Photoacoustic Spectra Recording of Exhaled Acetone and Main Breath Components</title>
    <abstract language="eng">Photoacoustic spectra of main breath components together with acetone are presented demonstrating spectral linearity towards different concentrations and compositions. The acetone 3σ detection limit at 1209 cm−1 is 0.28 ppbV</abstract>
    <parentTitle language="deu">Optical Sensors and Sensing Congress 2022 (AIS, LACSEA, Sensors, ES)</parentTitle>
    <identifier type="doi">10.1364/AIS.2022.ATu3G.1</identifier>
    <enrichment key="OtherSeries">Technical Digest Series (Optica Publishing Group, 2022), paper ATu3G.1.</enrichment>
    <licence>Keine Lizenz - Es gilt das deutsche Urheberrecht: § 53 UrhG</licence>
    <author>Jonas Pangerl</author>
    <author>Elisabeth Wittmann</author>
    <author>Stefan Weigl</author>
    <author>Max Müller</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
  <doc>
    <id>7330</id>
    <completedYear/>
    <publishedYear>2024</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber/>
    <edition/>
    <issue/>
    <volume/>
    <type>preprint</type>
    <publisherName>Elsevier / SSRN</publisherName>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>--</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Photoacoustic Trace-Analysis of Breath Isoprene and Acetone Via Interband- and Quantum Cascade Lasers</title>
    <abstract language="eng">This research presents two laser-based photoacoustic approaches for analyzing exhaled breath isoprene and acetone. The integration of a PTR-ToF-MS as a reference device ensured the reliability and accuracy of the PAS systems that is based on an ICL for isoprene and a QCL for acetone detection. The calibration yielded limits of detection of 26.9 ppbV and 1.7 ppbV, respectively, and corresponding normalized noise equivalent absorption coefficients (NNEAs) of 5.0E-9 Wcm-1Hz-0.5 and 4.9E-9 Wcm-1Hz-0.5. Laboratory as well as real breath sample measurements from alveolar breath revealed a robust system performance, with only one outlier within the static isoprene measurements. However, discrepancies emerged under dynamic breath sampling conditions, emphasizing the need for further optimization. Especially by knowing the dynamic nature and endogenous origin of exhaled isoprene our findings highlight the potential of breath analysis for non-invasive physio-metabolic and pathophysiological monitoring towards point-of-care devices.</abstract>
    <identifier type="doi">10.2139/ssrn.4834735</identifier>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">true</enrichment>
    <licence>Keine Lizenz - Es gilt das deutsche Urheberrecht: § 53 UrhG</licence>
    <author>Jonas Pangerl</author>
    <author>Pritam Sukul</author>
    <author>Thomas Rück</author>
    <author>Lukas Escher</author>
    <author>Wolfram Miekisch</author>
    <author>Rudolf Bierl</author>
    <author>Frank-Michael Matysik</author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>photoacoustic spectroscopy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>breath analysis/profiling</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>real-time mass spectroscopy</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>isoprene</value>
    </subject>
    <subject>
      <language>deu</language>
      <type>uncontrolled</type>
      <value>acetone</value>
    </subject>
    <collection role="institutes" number="FakANK">Fakultät Angewandte Natur- und Kulturwissenschaften</collection>
    <collection role="persons" number="bierlsappz">Bierl, Rudolf (Prof. Dr.) - Sensorik-ApplikationsZentrum</collection>
    <collection role="othforschungsschwerpunkt" number="16317">Sensorik</collection>
    <collection role="institutes" number="">Sensorik-Applikationszentrum (SappZ)</collection>
  </doc>
</export-example>
