DaKS - University of Kassel's research data repository

DaKS is the institutional repository of the University of Kassel for research data. It offers structured storage of research data alongside with descriptive metadata, long-term archiving for at least 10 years and – if requested – the publication of the dataset with a DOI.

DaKS is managed by the university library and the IT Service Centre of the University of Kassel. It is hosted at Philipps-Universität Marburg. We are happy to advise you via daks@uni-kassel.de.

Recent Submissions

Gonioreflectometric measurements in the mid-wavelength infrared range
(Universität Kassel) Noori, Hoschang
A gonioreflectometer for the mid-wavelength infrared range was built to measure the emissivity of rough surfaces without contact. Gonioreflectometric measurements were conducted for several surface materials. Every HDF5-File contains the thermal images for a camera angle and incident angles from 1° to 90°, with open and closed chopper. For the camera angle of 15°, the data for incident angles from 3° to 87° degree is usable. Usable is the data from 1° to 87° for Camera angles of 20°, 30°, 40°, 45°, 50°, 60°, 70°, 80°, 85°. The thermal images are available as temperature values in °C, radiance value in W/sr/m^2 and digital values. The radiance values are determined via Plancks Law. The rotation stage for the integrating sphere moves continuously with 10° per second, and the MWIR camera takes 10 HDR thermal image every second with the fastest possible frame rate to ensure the correctness of the angle.
Assessing biodiversity of apricot landraces in Gilgit-Baltistan (Pakistan) using morphological and genetic traits (Microsatellite data)
(Universität Kassel) Wiehle, Martin; ALAM, IFTIKHAR; Nawaz, Muhammad Arslan; Braun-Lüllemann, Annette; Gailing, Oliver; Müller, Markus; Buerkert, Dr. Andreas
For centuries, apricots (Prunus armeniaca L.) were used as a staple food in Gilgit-Baltistan (G-B), northern Pakistan where their high nutritional and medicinal value is still highly appreciated by many inhabitants. Here, many locally recognized landraces (referring to mainly undescribed varieties or cultivars) of apricot are available of which some are at risk of extinction, because of current human preferences replacing landraces by modern cultivars and other crop species. To assess the distribution, diversity, management and use of apricots in G-B, we made use of the region’s unique topography by employing the so-called ‘Dead-end valley sampling’ approach. It allowed to test the influence of market distance on morphological parameter classes. In 2021 and 2022, landrace richness, quantitative and qualitative morphological characteristics, and genetic diversity were investigated from 240 samples of several valleys. By employing 12 SSR markers we elaborated the identification of homonyms and synonyms of landraces. In addition, a total of 52 households from five valleys with three villages each as well as employees of two arboricultural research centres of Gilgit and Baltistan were interviewed.
Among the sampled landraces, 120 different landraces were named by farmers of which Halman, Habi, Karfo chuli and Shikanda were most frequent. The highest Simpson index (0.96) was found in Ishkoman, the most western valley studied. The high average genetic diversity (He = 0.729) across three identified genetic clusters, was supported by high excess of heterozygotes, indicated by negative inbreeding coefficients. Across-valley β-diversity was 0.737. Correlation between phenotypic and genetic dendrograms was moderate (r = 0.45, p = 0.001) indicating genetically linked fruit traits, warranting further investigation. Due to its considerable genetic and phenotypic diversity, Gilgit-Baltistan constitutes an important reservoir of apricot germplasm for future breeding programs. Promoting local landraces—potentially even recognized as distinct varieties—could help farmers diversify production and income sources while preserving the region’s historically significant bio-cultural heritage. To realize this potential, conservation and management measures combined with stakeholder-driven research and controlled breeding initiatives for effective monitoring will be essential.
Correlation between compounding parameters and the degradation of poly(lactic acid)/starch composites during the compounding process [Dataset]
(Universität Kassel) Goetjes, Victoria; Zarges, Jan-Christoph; Heim, Hans-Peter
Poly(lactic acid) (PLA) is one of the most important bioplastics with good mechanical properties and reduced environmental impact compared to petro-based plastics. In order to improve both sustainability and cost-efficiency, PLA can be filled with low-cost particles, such as native potato starch. However, during processing in a twin-screw extruder, PLA and starch are prone to thermal, hydrolytic, and mechanical degradation, which can deteriorate composite properties. This dataset systematically describes how key compounding parameters including screw speed and configuration, temperature profile and PLA pre-drying time influence the properties of PLA-starch composites containing 50 wt.% native potato starch. Various analytical methods were used to characterize the properties (Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Melt Volume Rate (MVR), Scanning Electron Microscopy (SEM), color measurements). The results show that thermal properties remain largely unaffected by the chosen compounding parameters. In contrast, significant changes are observed in thermal stability, viscosity, color, and morphological structure with changes in process parameters. Higher screw speeds and temperatures increase thermomechanical stress, leading to a higher MVR value, indicating lower molecular weight. Color measurements reveal significant discoloration due to starch degradation and PLA chain scission, which correlate with increasing yellow and red tones and a decrease in brightness at higher thermomechanical stress due to elevated screw speed and temperatures. Overall, the data emphasizes the complex interactions between process parameters, in particular screw speed and temperature profile as well as the physicochemical properties of PLA-starch composites, providing valuable insights for the design of the compounding process in order to prevent pre-damage to the composites.
IMPORTANT: In case you use the data please cite our corresponding article.
Calculation of a simplified reference factor for estimating the amount of maize used as cattle feed in the Weser-Ems Region
(Universität Kassel) Beila, Ilze; Hoffstede, Uwe; Kasten, Julia; Beil, Michael; Wachendorf, Michael; Wijesingha, Jayan
This data set is a supplementary material to the publication "Remote sensing-based long-term assessment of bioenergy policy impact on agricultural land cover change: A case study of biogas in the Weser-Ems region in Germany" (Beila et al., 2025). It contains the calculation of a simplified reference factor for estimating the amount of maize silage used as cattle feed in the Weser-Ems Region, including assumptions and references used for the calculation. In addition, the data set includes graphs illustrating the share of maize silage used for biogas production in different municipalities, and the change in the number of cattle between years 1999 to 2020 per municipality.
Oasis Agriculture in Pakistan - Introductory video
(Universität Kassel) Buerkert, Dr. Andreas; Wiehle, Martin; Schlecht, Eva; Hoffmann, Ellen
This introductory video gives an impression into the folk tales collected in the book "Oasis Agriculture in Pakistan" and the accompanying videos.