Virtual reality (VR) is on the edge of getting a mainstream platform for gaming, education and product design. The feeling of being present in the virtual world is influenced by many factors and even more intriguing a single negative influence can destroy the illusion that was created with a lot of effort by other measures. Therefore, it is crucial to have a balance between the influencing factors, know the importance of the factors and have a good estimation of how much effort it takes to bring each factor to a certain level of fidelity. This paper collects influencing factors discussed in literature, analyses the immersion of current off-the-shelf VR-solutions and presents results from an empirical study on efforts and benefits from certain aspects influencing presence in VR experiences. It turns out, that sometimes delivering high fidelity is easier to achieve than medium fidelity and for other aspects it is worthwhile investing more effort to achieve higher fidelity to improve presence a lot.

Supported titanium dioxide-based photocatalysts were investigated for the degradation of pharmaceuticals under irradiation with UV−A LEDs. Focus of the presented research was placed on the degradation kinetics under different matrix influences and energy flux densities of UV−A radiation. The chemical parameters, pH, orthophosphate, nitrogen concentration and background organic concentration were investigated. The results were evaluated by time-resolved measurement of the concentrations and by calculating and plotting the first-order degradation rate. The results showed clear differences in the rates of degradation of each compound, with diclofenac being the most easily degraded and metoprolol the most resistant. When the influence of energy flux density was examined, a linear relationship between degradation rate and the square root of energy flux density was confirmed. The organic background matrix has a strong influence on the degradation kinetics of the compounds. Nitrogen and orthophosphate slow down the degradation much less than the organic background matrix. Investigating the pH influence, it could be shown that almost no degradation is detected in the basic pH range. The results were illustrated with the help of a radar diagram, which can show all dependencies at a glance.

In the present work, a suitable experimental setup was developed to successfully apply advanced oxidation processes (AOP) to real groundwater matrices. This setup combines an O3-bubble column reactor with a carrier-bound TiO2/UV-system. The degradation of various chlorinated ethene and methane derivatives commonly found of chlorinated volatile organic compound polluted regional groundwater samples was investigated. Because of known issues within water remediation using AOP such as toxification by transformation products, this study aimed at complete mineralization of the contained organic micropollutants. Moreover, the influences of variable process parameters such as flow rate, ozone concentration, and radiation dose on process performance were statistically evaluated and discussed. Parameter optimization using a Box-Behnken experimental design resulted in very promising degradation rates. It was thus possible to achieve a degradation rate of at least 98% for cis-dichloroethene, trichloroethene and tetrachloroethene and 85% for trichloromethane without formation of transformation products. The results of this work open up the possibility of developing innovative technologies based on AOP, which can be universally applied even to challenging matrices such as groundwater.

Immobilized titanium dioxide catalysts were used within a photocatalytic immersion rotary body reactor, which was connected to a substream ozonation unit to remove micro-pollutants from wastewater. Within this work data on the behavior of cumulative parameters during treatment of wastewater by photocatalysis and photocatalytic ozonation are provided. The investigated parameters are spectral absorption coefficient at 254 nm (SAC254), total organic carbon (TOC) and chemical oxygen demand (COD). All experiments were carried out using secondary effluent from the same wastewater treatment plant. For the parameter SAC254, consistent concentration curves and dependencies to operational parameters of the experimental system could be measured. The measurements of the parameters TOC and COD showed greater uncertainties, although basic trends could nonetheless be observed. A good linear correlation (R2 < 0.85) between the reduction of SAC254 and 8 micro-pollutants for photocatalysis and photocatalytic ozonation was found. This confirms the suitability of the SAC254 as a control parameter for a large-scale application of a photocatalytic 4th treatment stage. A linear correlation between measured TOC and COD degradation rates was possible with a coefficient of determination of 0.58–0.86. The simultaneous decrease of TOC and COD is an indicator for a mineralization of the treated wastewater matrix.

Der Rückgriff auf Algorithmen und datenbasierte Entscheidungsmuster sowie zunehmend auch auf KI im Rahmen der „Algorithmic Governance“ verändert die praktische Politik grundlegend. Dabei unterscheiden sich die Einsatzfelder hinsichtlich ihres Autonomiegrades. Das Spektrum reicht von klassischen Analyseleistungen bis hin zu völlig autonomen politischen Entscheidungen durch KI.

Als vor drei Jahren die Idee zur Technologieinitiative KOMMUNAL 4.0 entstand, der nun zur Plattforum Kommunal 4.0 e. V. geführt hat, war das Thema Digitalisierung in der Wasserwirtschaft nur vereinzelt präsent. Ausgehend von dem Gedanken, die Grundidee von Industrie 4.0 auf die kommunale Wasserwirtschaft zu übertragen, stellten die Initiatoren von KOMMUNAL 4.0 fest, dass schon seit Jahren unzählige Daten in zahlreichen wasserwirtschaftlichen Anlagen und Objekten erfasst und archiviert wurden. Zumeist beschränkte sich die Datennutzung auf die aktuelle Prozessbeobachtung oder die Nachweisführung der Regel- und Gesetzeskonformität gegenüber den zuständigen Behörden.

Überall in Wirtschaft und Gesellschaft wird von Digitalisierung und dem Internet der Dinge gesprochen, zunehmend auch in der kommunalen Wasserwirtschaft. Impulsgeber ist die Digitalisierungsoffensive der Industrie, zusammengefasst unter dem Begriff Industrie 4.0. Diese basiert auf intelligenten, digital vernetzten Systemen, die eine sich selbst organisierte Produk­tion ermöglichen sollen.

Carrier-bound titanium dioxide catalysts were used for the photocatalytic conversion of nitrogen dioxide. In this context, inexpensive metal oxide sensors were tested for their usefulness in the investigation and characterization of the photocatalysts. UV-A light emitting diodes of wavelength 365 nm stimulated the catalysts. By dimming the light emitting diodes, the influence of the energy flux density on the conversion kinetics could be investigated. The observed conversation followed first-order kinetics. The light intensity has shown a large influence at lower irradiances. At high irradiances an increase in recombination effects can be assumed, which makes irradiances greater than 40 W/m2 inefficient. From that point on no significant increase in the rate of conversation could be measured. The photon efficiency at low irradiances was determined to be 4.55% decreasing to 0.59% at higher irradiances. The flow rate of gas passing through the catalysts appears to have a linear effect on the overall rate of conversion. This is evidenced by a constant half-life within the reactor in relation to variable flow rate. The sensors have been shown to be calibratable and sufficiently stable, which raises the possibility of using the sensors for spatially resolved measurements within reaction systems.

Persistent and mobile (PM) substances are being recognized as serious threats to water resources and drinking water suppliers have to use advanced treatment if raw waters are contaminated with such compounds. In this study, analytical methods for 25 micropollutants for which insufficient or no data on their occurrence in surface waters and on their behavior during drinking water treatment were available, were developed. More than 120 surface water samples were analyzed and laboratory tests were performed to evaluate the compounds' behavior during aerobic bank filtration (BF), activated carbon treatment, and ozonation. Ensulizole, 1,3-diphenylguanidine and 2-acrylamido-2-methylpropane sulfonic acid revealed the highest detection frequencies in the Rhine river. Concentration level and detection frequency correlated positively with the wastewater fraction. However, street run-off is likely an additional discharge pathway for 1,3-diphenylguanidine. In simulated BF, seven (six) substances could be classified as persistent (very persistent). By applying powdered activated carbon, 42% of the substances were well removed as was the case for 50% of the compounds when applying 0.2 mg/L O3. In total, eight of the substances detected in surface waters were weakly removed by at least one of the investigated removal processes and may cause problems for drinking water suppliers.

Unter dem Begriff der Algorithmic Governance wird verstärkt der Einsatz von Algorithmen als Ergänzung oder auch als vollständiger Ersatz menschlicher politischer Entscheidungen diskutiert. Kommen dabei Methoden des maschinellen Lernens und KI zum Einsatz verändert dies die Rahmenbedingungen des Regierens in der Demokratie grundlegend.

Global waste expects to grow up to 3.4 billion tons by 2050, and the world is only 8.6 % circular; thus, our way of life is not sustainable. Therefore, society should move from the take--make--dispose principle towards a circular economy by optimizing resource consumption and reducing waste. Remanufacturing is a business model that enables the transformation by developing a circular economy in industrial companies. The remanufacturing process chain consists of disassembling, cleaning, sorting and inspection, reconditioning and reassembling. It extends the life cycle of products and reduces the use of new materials, energy consumption, costs, carbon dioxide emissions, landfill costs and waste compared to manufacturing new products. Due to the upcoming changes and transitions in the mobility sector focusing on electric drive systems, the circularity of their components will become a crucial lever for sustainability. An appropriate remanufacturing strategy is essential and enables manufacturer of electric drive systems to develop and implement sustainable remanufacturing. This paper presents a five-step implementation strategy for remanufacturing of e-mobility components. The five-step strategy includes Product Analysis, Market Research, Remanufacturing Technology Analysis, Remanufacturing Process Design and Business Models. This enables the implementation of a sustainable and market oriented business model in the e-mobility aftermarket.