IRF: Institutional Repository FHNW
Welcome to the publication and research database of the FHNW University of Applied Sciences and Arts Northwestern Switzerland.
The institutional repository contains publications, projects and student theses.
Further information can be found in the IRF manual (available in German).
Communities in IRF
Select a community to browse its collections.
- APS FHNW
- HABG FHNW
- HGK Basel FHNW
- HSI FHNW
- HLS FHNW
- HSM Basel FHNW
- HSA FHNW
- HTU FHNW
- HSW FHNW
- PH FHNW
Recently added
COLLEMBOT. AI-based counting of Collembola for OECD 232 tests
(Wiley, 2026) Wehrli, Micha; Meyer, Adrian; Souza da Silva, Éverton; van Loon, Sam; van Hall, Bart G.; van Gestel, Cornelis A. M.; Natal-da-Luz, Tiago; Döring, Max V. R.; Feldhaar, Heike; Mair, Magdalena; Jordan, Denis; Langer, Miriam
Ecotoxicological tests with soil organisms, such as the collembola Folsomia candida, are essential for assessing chemical risks in terrestrial ecosystems. However, the current Organization for Economic Co-operation and Development (OECD) 232 reproduction tests rely on manual counting of juvenile and adult Collembola, a process that is costly, labor-intensive, time-consuming and prone to operator bias. These limitations restrict data availability and hinder robust risk assessments. We therefore developed COLLEMBOT, an automated counting tool based on a YOLOv11 convolutional neural network, designed to integrate seamlessly into OECD workflows without protocol modifications. The model was trained on high-resolution images (n = 3207) from multiple laboratories and validated using 22 independent datasets (n = 1704 images) from Amsterdam (Netherlands), Basel (Switzerland), Bayreuth (Germany), Coimbra (Portugal) and Aarhus (Denmark). Datasets consisted of relevant standard soils (OECD artificial soils with 2.5%, 5% and 10% sphagnum peat; LUFA 2.2) and the springtail Folsomia candida. Automated counts showed strong agreement with manual counts (R² = 0.79–0.99). Dose-response curves derived from automated and manual counts strongly overlapped and effect concentrations (EC10 and EC50) differed minimally (Median %Δ 6.2 ± 23 and EC10–EC90 R2 ≥ 0.977), remaining within acceptable limits for regulatory risk assessment and confirming reliability. Time efficiency improved significantly: a test with approximately 300 images and up to 1,500 individuals per image was processed in less than 3 hr, compared to approximately 137 hr needed for manual counting, a reduction of approximately 97%. By reducing labor and improving reproducibility, COLLEMBOT enables broader hazard data generation for collembola, supporting science-based chemical risk assessment. The code and workflow are publicly available to facilitate adoption and community-driven development.
01A - Journal article
Interim urban uses and the politics of safety. Interrogating the emergent scholarly and practitioner knowledge base
(SAGE, 2026) Betschart, Thomas; Hagmann, Jonas
Formally sanctioned interim uses have become increasingly popular in European cities. They have also become linked more closely to debates on (in-)security, however, giving rise to specialized scholarly and practitioner literatures on that linkage. This commentary critically interrogates the directions of this emergent knowledge base. It situates the literatures and ponders the clarity with which they define their core concepts of security and interim space. It also reflects on the ways they apprehend the governance of such spaces, and on the impact of temporality and termination on the security politics of such places. The commentary argues that the emergent knowledge base highlights an increasingly popular phenomenon—but also that its conceptual precision requires further sharpening, and that it ought to be developed into a considerably more holistic, empirical and critical perspective more generally.
01A - Journal article
Design and performance assessment of continuous crystallization processes resolving racemic conglomerates
(American Chemical Society, 12.02.2018) Köllges, Till; Vetter, Thomas
Continuous crystallization processes achieving the complete resolution of racemic feed mixtures of conglomerate forming substances are presented. The processes considered rely on the principles of preferential crystallization or attrition-enhanced deracemization (Viedma ripening). A single mechanistic population balance model is shown to describe both operating modes. For the case of isothermal Viedma ripening, a shortcut method is introduced that allows the rapid and computationally efficient design of processes using a single or multiple ripening stages. The achievable productivity and enantiomeric purity are determined for all process variants in a wide range of operating conditions, and Pareto optimal operating points are identified. Since our results are obtained with a consistent set of kinetics for all operating modes, an unbiased comparison is enabled. It is shown that the productivity of the ripening process can be improved by using cascades of multiple crystallizers, but that the preferential crystallization process still achieves higher productivity at full enantiomeric purity.
01A - Journal article
Nucleation
(Wiley, 10.12.2018) Mazzotti, Marco; Vetter, Thomas; Ochsenbein, David R.; Maggioni, Giovanni M.; Lindenberg, Christian; Hilfiker, Rolf; Raumer, Markus von
04A - Book part
Salts, cocrystals, and ionic cocrystals of a “simple” tautomeric compound
(American Chemical Society, 16.10.2018) Wang, Ting; Stevens, Joanna S.; Vetter, Thomas; Whitehead, George F. S.; Vitorica-Yrezabal, Iñigo J.; Hao, Hongxun; Cruz-Cabeza, Aurora J.
We have investigated the cocrystallization behavior of AHMP (2-amino-6-methyl-1,4-dihydropyrimidin-4-one) with a series of acids and imide coformers. Being a base able to tautomerize, at the molecular level, AHMP may exist as three different neutral tautomers or, if protonated, in the form of several cationic species. Crystal engineering concepts were used in order to attempt selective isolation of several tautomers. For this, a series of acids and imides were used as coformers. Cocrystallization with acids resulted in 11 new solid forms including salts, ionic cocrystals, and cocrystals. Cocrystallizations with imides did not afford any new forms, while cocrystallization with saccharin afforded two polymorphic salts and an ionic cocrystal. Two of the possible tautomers were obtained as well as one of the cationic species. DFT calculations were carried out in order to rationalize the molecular species obtained as well as the supramolecular motifs. Despite being a small “simple” molecule, AHMP has a very rich and interesting solid form landscape with cocrystals containing two different tautomers, many salts (some of which are polymorphic), and multiple ionic cocrystals.
01A - Journal article