@article{HasanuzzamanBuchwaldSchunketal.2024, author = {Hasanuzzaman, Gazi and Buchwald, Tom and Schunk, Christoph and Schr{\"o}der, Andreas and Egbers, Christoph and Hampel, Uwe}, title = {DATIV - Remote enhancement of smart aerosol measurement system using Raspberry Pi based distributed sensors}, series = {Sensors}, volume = {24}, journal = {Sensors}, number = {13}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s24134314}, year = {2024}, abstract = {Enclosed public spaces are the hotspots for airborne disease transmission. To measure and maintain indoor air quality in terms of airborne transmission, an open source, low cost and distributed array of Particulate Matter Sensors has been developed and named as Dynamic Aerosol Transport for Indoor Ventilation or DATIV system. This system can use multiple Particulate Matter Sensors (PMS) simultaneously and can be remotely controlled using a Raspberry Pie based operating system. The data acquisition system can be easily operated using the GUI within any common browser installed on a remote device such as a PC or Smartphone with corresponding IP address. The software architecture and validation measurements are presented together with possible future developments.}, subject = {Particulate matter; Aerosol; Low cost measurement system; Distributed sensors; Indoor ventilation}, language = {en} } @article{BuchwaldHasanuzzmanMerboldetal.2023, author = {Buchwald, Tom and Hasanuzzman, Gazi and Merbold, Sebastian and Schanz, Daniel and Egbers, Christoph and Schr{\"o}der, Andreas}, title = {Large-scale flow field and aerosol particle transport investigations in a classroom using 2D-Shake-The-Box Lagrangian Particle Tracking}, series = {Heliyon}, volume = {9}, journal = {Heliyon}, number = {12}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2405-8440}, doi = {10.1016/j.heliyon.2023.e22826}, year = {2023}, abstract = {Infections with COVID-19 in enclosed public spaces, where virus-laden aerosol particles can accumulate over time, have significantly contributed to the rapid spread of the virus. It is therefore of great importance to understand the transport and dispersion process of aerosol particles in such spaces, especially against the background of future pandemics. In this work, we present a Lagrangian-Particle-Tracking experiment to assess the mixed convective flow in a classroom with different ventilation strategies. For this purpose, thermal plumes were created by heated dummies, and a collimated LED light-sheet with ~0.4 m thickness was used for illumination of helium filled soap bubbles (HFSB) acting as passive tracer particles. In this way, the Lagrangian trajectories of the particles were recorded at two approximately 4.2 m × 2.8 m large fields using the novel 2D-Shake-The-Box-Method. As a result, time-resolved trajectories of over 300,000 simultaneously tracked HFSB have been reconstructed, so that both small-scale and large-scale properties of the flow are visualized quantitatively across the entire cross-section of the room. The trajectories show that the thermal plumes create lengthwise circulating vortices, which cannot be destroyed across the entire cross-section of the room by opening or tilting a window. Furthermore, the mixing in the room through the operation of an air purifier is higher compared to opening a window, which suggests that this strategy in combination with its air filtering capability is the most effective strategy to prevent infections.}, subject = {Shake-the-box; Lagrangian-particle-tracking; Aerosol particle spreading; Room ventilation; Covid-19; Lagrangesche Partikelverfolgung; Ausbreitung von Aerosolpartikeln; Raumbel{\"u}ftung; Aerosol; Lagrange-Darstellung ; Bel{\"u}ftung; Klassenzimmer}, language = {en} }