Specht, Patrick

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Specht
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Patrick
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Specht, Patrick

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2021 - 20227
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Thema: 500 - Naturwissenschaften und Mathematik ×

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Gerade angezeigt 1 - 7 von 7
  • Vorschaubild nicht verfügbar
    Publikation
    The organic coating unit, an all-in-one system for reproducible generation of secondary organic aerosol
    (06.09.2022) Keller, Alejandro; Kalbermatter, Daniel; Specht, Patrick; Steigmeier, Peter; Wolfer, Katherin; Resch, Julian; Kalberer, Markus; Hammer, Tobias; Vasilatou, Konstantina
    06 - Präsentation
  • Vorschaubild nicht verfügbar
    Publikation
    The organic coating unit, an all-in-one system for reproducible generation of secondary organic matter aerosol
    (Taylor & Francis, 18.08.2022) Keller, Alejandro; Kalbermatter, Daniel M.; Wolfer, Kate; Specht, Patrick; Steigmeier, Peter; Resch, Julian; Kalberer, Markus; Hammer, Tobias; Vasilatou, Konstantina [in: Aerosol Science and Technology]
    We report on a novel automated oxidation flow reactor to generate a wide variety of organic aerosol samples. The instrument is equipped with a humidifier, a dosing system for volatile organic precursors and an oxidation flow reactor (OFR) for generation of secondary organic matter (SOM). The instrument, known as organic coating unit (OCU), can produce homogeneously nucleated SOM particles or, used in combination with a standard combustion generator (e.g., a diffusion flame soot generator or any other seed particle), particles coated with a controlled amount of SOM. The physical and chemical properties of the generated particles can be controlled in a simple manner by selecting through a touch-screen target values for parameters, such as organic gaseous precursor concentration, humidity, and UV (ultraviolet) light intensity. Parameters and measured quantities are automatically stored in text files for easy export and analysis. Furthermore, we provide stable operation conditions and characterize the physicochemical properties of the generated aerosols with an array of methods, including transmission electron microscopy (TEM), thermal-optical analysis and liquid chromatography coupled with mass spectrometry (LC-MS). This all-in-one instrument is robust, compact, portable, and user-friendly, making it ideal for laboratory or field-based aerosol studies.
    01A - Beitrag in wissenschaftlicher Zeitschrift
  • Vorschaubild
    Publikation
    The organic coating unit, an all-in-one system for reproducible generation of secondary organic aerosol
    (22.06.2022) Keller, Alejandro; Specht, Patrick; Steigmeier, Peter; Kalbermatter, Daniel; Hammer, Tobias; Vasilatou, Konstantina; Wolfer, Kate; Resch, Julian; Kalberer, Markus
    06 - Präsentation
  • Vorschaubild nicht verfügbar
    Publikation
    Employment of novel tools for the continuous characterization of the carbonaceous fraction in ambient aerosol
    (13.09.2021) Keller, Alejandro; Specht, Patrick; Steigmeier, Peter; Weingartner, Ernest
    06 - Präsentation
  • Vorschaubild nicht verfügbar
    Publikation
    Performance of the new continuous carbonaceous aerosol measurement system FATCAT during long term unattended measurement campaigns
    (23.06.2021) Keller, Alejandro; Specht, Patrick; Steigmeier, Peter; Weingartner, Ernest
    06 - Präsentation
  • Vorschaubild nicht verfügbar
    Publikation
    High resolution unattended particle-bound total carbon measurements and source identification at the Jungfraujoch global GAW station
    (18.05.2021) Keller, Alejandro; Specht, Patrick; Steigmeier, Peter; Weingartner, Ernest
    Total aerosol carbonaceous mass (TC) is a major constituent of atmospheric fine aerosol not yet continuously monitored with adequate time resolution. Adding a TC measurement to existing measurement programs is crucial for comprehensive interpretation of the impact of aerosols. To fill this gap, we developed the “fast thermal carbon totalizator” (FATCAT) for long-term unsupervised monitoring of TC. FATCAT has been deployed since 2019 at diverse sites including the Jungfraujoch global GAW station (JFJ). FATCAT collects particles on a metallic filter, and subsequently heats it to 800°C under an oxidizing atmosphere. The limit of detection is LoD=0.2 µg of carbon (µg-C). At the reduced atmospheric pressure of the JFJ, which limits the sampling flow, this corresponds to TC=0.3 µg-C/m3 using a time resolution of two hours. We discuss our experience during the first two year of continuous TC measurements and the possibility of using our instrument to distinguish carbonaceous aerosol from different source using fast, 50 seconds, thermograms. This unique feature allows us to identify source specific fingerprints. Several high TC episodes during September 2020 at JFJ show the typical pattern for biomass combustion. Back trajectories attribute them to long-range transported emissions from Californian wildfires. Graphitic carbon from, e.g., local fossil fuel combustion evolves at higher temperatures. The data collected at the JFJ is already the longest produced TC dataset for this site without instrument related interruptions. The dataset generated by our instrument and post-analysis data products represent an improvement to the available measurement inventory. It can serve as quality control for other measurement systems. Prominently, measurements of eBC via MAAP or Aethalometer and organic mass using ToF-ACSM. TC data can be used in parallel to these devices as a quality check, and to warrant carbon mass closure and reduce systematic biases.
    06 - Präsentation
  • Vorschaubild nicht verfügbar
    Publikation
    High resolution unattended particle-bound total carbon measurements and source identification at the Jungfraujoch global GAW station
    (2021) Keller, Alejandro; Specht, Patrick; Steigmeier, Peter; Weingartner, Ernest
    06 - Präsentation