Ostwestfalen-Lippe University of Applied Sciences and Arts
Publikationen an der Technischen Hochschule Ostwestfalen-LippeNot a member yet
6551 research outputs found
Sort by
Thermo-oxidative aging of linear and branched alcohols as stability criterion for their use as e-fuels
No full textThe decarbonization of the energy supply is one of the biggest and most important challenges of the 21st century. This paper contributes to the solution of the energy crisis by investigating the stability of alcohols as e-fuels. The focus is on the investigation of the aging mechanism of the linear alcohols 1-hexanol and 1-octanol compared to the iso-alcohol 2-hexanol. It is analysed in detail how the time-dependent aging varies depending on the chain length and the position of the hydroxy-group, both in the liquid and in the gas phase. It is shown that a variety of aging products such as aldehydes, acids, short-chain alcohols and esters are formed during the aging of the n-alcohols by oxidation, decarboxylation, oxidative C-C bond cleavage and esterification. In contrast, the decomposition of the iso-alcohol is significantly lower. The results show that the total acid number is significantly higher for aged n-alcohols than for the aged iso-alcohos, while the kinematic viscosity decreases for all alcohols during aging. Carbon mass balancing shows that after accelerated aging for 120 hours, around 80% of the iso-alcohol is still present, compared to only around 57-63% for the n-alcohols. In addition, significantly fewer acids are formed with the iso-alcohol. In this study, iso-alcohols have a higher stability against thermo-oxidative aging compared to n-alcohols, showing their potential as e-fuels. Furthermore, the chain length of the alcohols has also an influence on aging, as more different aging products can be formed with increasing chain length.
This paper contributes to the solution of the energy crisis by investigating the stability of alcohols as e-fuels. The focus is on the investigation of the aging mechanism of 1-hexanol and 1-octanol compared to the 2-hexanol
Combining a Multi‐Lake Model Ensemble and a Multi‐Domain CORDEX Climate Data Ensemble for Assessing Climate Change Impacts on Lake Sevan
No full textGlobal warming is shifting the thermal dynamics of lakes, with resulting climatic variability heavily affecting their mixing dynamics. We present a dual ensemble workflow coupling climate models with lake models. We used a large set of simulations across multiple domains, multi‐scenario, and multi GCM‐ RCM combinations from CORDEX data. We forced a set of multiple hydrodynamic lake models by these multiple climate simulations to explore climate change impacts on lakes. We also quantified the contributions from the different models to the overall uncertainty. We employed this workflow to investigate the effects of climate change on Lake Sevan (Armenia). We predicted for the end of the 21st century, under RCP 8.5, a sharp increase in surface temperature and substantial bottom warming , longer stratification periods (+55 days) and disappearance of ice cover leading to a shift in mixing regime. Increased insufficient cooling during warmer winters points to the vulnerability of Lake Sevan to climate change. Our workflow leverages the strengths of multiple models at several levels of the model chain to provide a more robust projection and at the same time a better uncertainty estimate that accounts for the contributions of the different model levels to overall uncertainty. Although for specific variables, for example, summer bottom temperature, single lake models may perform better, the full ensemble provides a robust estimate of thermal dynamics that has a high transferability so that our workflow can be a blueprint for climate impact studies in other systems
Vielfalt der Bioökonomie an der TH OWL - Innovationen und Praxislösungen für eine nachhaltige Zukunft
No full textFlächendeckende Bestimmung des dominierenden Abflussprozesses als Entscheidungshilfe zur Auswahl geeigneter Standorte für naturbasierte Lösungen zur Sturzflutvorsorge. Eine Analyse in ausgewählten hydrologischen Einzugsgebieten im Weserbergland
No full textSemi-automated vs. manual: Comparative study of cell culture counting methods using validation parameters
No full textDetermining cell density and cell viability is fundamental for any cell cultivation process. In addition to the manual counting method using hemocytometers, (semi-)automated methods offer advantages such as lower variability and shortened analysis times. However, these methods should provide at least comparable results to the manual method, which is why a comparison of methods is essential. We conducted a dilution series experimental design according to ISO 20391-2:2019 and compared two cell counting methods based on validation parameters aligned with the ICH Q2(R1) guideline. Regarding specificity and linearity, the manual (hemocytometer) and semi-automated (Countstar BioTech®) method exhibited similar results in the two evaluated characteristics total cell density and cell viability of CHO-K1 cells. Regarding repeatability of determining total cell density, the semi-automated method achieved significant (α = 0.05) better results with average relative standard deviations of 9 %. Concerning repeatability of the cell viability measurement, no significant difference between the two methods were shown. These results show the suitabililty of the dilution series experimental design. For the applied example, they indicate that the investigated semi-automated method is an appropriate alternative to the manual method
Innovative Valorization of Oat By-Products
No full textAim:
Food loss and waste are significant challenges to the sustainability of food systems. This study aims to explore innovative approaches for reducing food waste and valorizing side-streams, focusing specifically on oat okara, a by-product of oat milk production. The aim is to extract and purify proteins from oat okara through enzymatic processes, with the ultimate goal of creating a sustainable protein source for various applications.
Method:
Oat okara was subjected to enzymatic treatment and hydrolysis using a pressure filter press. Enzymatic processes were optimized to achieve high protein yields with purity exceeding 80%. The hydrolysate was then concentrated using a rotary evaporator and purified through membrane filtration to remove impurities and smaller molecules.
Additionally, a chromatography system was employed to further purify the protein fractions and isolate individual peptides. This comprehensive approach ensures the extraction of high-quality proteins suitable for various applications.
Results:
The enzymatic extraction and purification process yielded proteins with high purity (>80%) from oat okara. The pressure filter press efficiently facilitated enzymatic hydrolysis, resulting in a hydrolysate rich in protein content. Subsequent concentration and purification steps effectively removed impurities, enhancing the quality of the protein extract.
Furthermore, chromatography enabled the isolation of individual peptides, further enhancing the value-added potential of the extracted proteins.
Conclusion:
This study demonstrates the feasibility of enzymatic extraction and purification of proteins from oat okara, a by-product of oat milk production. The extracted proteins hold promise as sustainable alternatives for various applications, including food and cosmetic industries. By valorizing side-streams and reducing food waste, this approach contributes to the development of more sustainable food systems
Do internationally operating companies act in a socially sustainable manner? An empirical comparison of disclosure regarding employee matters and human rights matters
No full textAlthough employee matters and human rights matters directly affect the corporate environment, research in this area remains nascent. To obtain evidence on the extent of corporate compliance with due diligence obligations, sustainability reporting has been analyzed. Grounded in institutional theory, this study examines the effects of regulation, the degree of professionalization, and sector-specific variations. The research employs a qualitative-interpretative content analysis, focusing on the reporting behaviour of 12 listed companies in Germany from both high-risk and low-risk sectors. The reporting periods selected are 2017 and 2021, chosen to examine the impact of regulations under the Non-Financial Reporting Directive 2014/95/EU (NFRD) and the Second Shareholder Rights Directive. The results show that regulation influences the disclosure of employee matters and human rights matters. Furthermore, there is a difference in the level of specificity regarding these matters, as well as in terms of opportunities and risks. The intensity of regulation also has an impact on the comparability and quality of reporting. By analyzing the reporting behaviour concerning two central social matters, this study compares the disclosure of employee matters and human rights matters, thereby contributing to the broader understanding of corporate social responsibility as well as gaining knowledge regarding sustainable corporate governance processes fostering the transformation towards sustainability-related actions across different sectors. In addition, the study examines both existing (NFRD) and forthcoming Corporate Sustainability Reporting Directive (CSRD) EU reporting obligations within a unified research framework, thus contributing to the advancement of sustainability reporting from an institutional theoretical perspective
Elasto-mechanical properties of thermo-hygro-mechanical (THM) densified oil palm sawn timber
No full textOil palm wood is mainly low in density and since strength and stiffness correlate with density, this study aimed to enhance the properties of oil palm wood through thermo-hygro-mechanical (THM) densification. In contrast to other studies using small laboratory-sized specimens, this study examined the densification of oil palm boards in sawn timber dimensions of 2.0 m length. Modulus of elasticity (MOE) and modulus of rupture (MOR) in bending, shear strength and shear modulus parallel by two-plate shear test and Young’s modulus in the three main directions as well as shear modulus in the three planes by ultrasonic testing were determined at densified and undensified specimens. The bending properties were increased to considerably higher levels and a compression ratio of 60% showed higher MOE and MOR values than that of 40%; whereas for boards of the inner part of the trunk, a compression ratio of 60% showed better results than that of 75%. The shear properties were only slightly increased through densification. Densification can improve the properties of oil palm wood. However, the wide range of density and properties found in natural oil palm wood is also present in densified oil palm wood
