TY - JOUR A1 - Bung, Daniel Bernhard A1 - Crookston, Brian M. A1 - Valero, Daniel T1 - Turbulent free-surface monitoring with an RGB-D sensor: the hydraulic jump case JF - Journal of Hydraulic Research Y1 - 2020 U6 - https://doi.org/10.1080/00221686.2020.1844810 SN - 1814-2079 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Bung, Daniel Bernhard A1 - Erpicum, Sébastien A1 - Tullis, Blanke P. T1 - Advances in hydraulic structures engineering JF - Journal of Hydraulic Engineering Y1 - 2020 U6 - https://doi.org/10.1061/(ASCE)HY.1943-7900.0001851 SN - 0733-9429 (Druckausgabe) SN - 1943-7900 (Online-Ausgabe) VL - 147 IS - 1 PB - ASCE CY - Reston, Va. ER - TY - JOUR A1 - Bung, Daniel Bernhard A1 - Valero, Daniel T1 - Re-aeration on stepped spillways with special consideration of entrained and entrapped air JF - Geosciences N2 - As with most high-velocity free-surface flows, stepped spillway flows become self-aerated when the drop height exceeds a critical value. Due to the step-induced macro-roughness, the flow field becomes more turbulent than on a similar smooth-invert chute. For this reason, cascades are oftentimes used as re-aeration structures in wastewater treatment. However, for stepped spillways as flood release structures downstream of deoxygenated reservoirs, gas transfer is also of crucial significance to meet ecological requirements. Prediction of mass transfer velocities becomes challenging, as the flow regime differs from typical previously studied flow conditions. In this paper, detailed air-water flow measurements are conducted on stepped spillway models with different geometry, with the aim to estimate the specific air-water interface. Re-aeration performances are determined by applying the absorption method. In contrast to earlier studies, the aerated water body is considered a continuous mixture up to a level where 75% air concentration is reached. Above this level, a homogenous surface wave field is considered, which is found to significantly affect the total air-water interface available for mass transfer. Geometrical characteristics of these surface waves are obtained from high-speed camera investigations. The results show that both the mean air concentration and the mean flow velocity have influence on the mass transfer. Finally, an empirical relationship for the mass transfer on stepped spillway models is proposed. Y1 - 2018 SN - 2076-3263 VL - 8 IS - 9 SP - Article number 333 PB - MDPI CY - Basel ER - TY - JOUR A1 - Bung, Daniel Bernhard A1 - Valero, Daniel T1 - Optical flow estimation in aerated flows JF - Journal of Hydraulic Research N2 - Optical flow estimation is known from Computer Vision where it is used to determine obstacle movements through a sequence of images following an assumption of brightness conservation. This paper presents the first study on application of the optical flow method to aerated stepped spillway flows. For this purpose, the flow is captured with a high-speed camera and illuminated with a synchronized LED light source. The flow velocities, obtained using a basic Horn–Schunck method for estimation of the optical flow coupled with an image pyramid multi-resolution approach for image filtering, compare well with data from intrusive conductivity probe measurements. Application of the Horn–Schunck method yields densely populated flow field data sets with velocity information for every pixel. It is found that the image pyramid approach has the most significant effect on the accuracy compared to other image processing techniques. However, the final results show some dependency on the pixel intensity distribution, with better accuracy found for grey values between 100 and 150. Y1 - 2016 U6 - https://doi.org/10.1080/00221686.2016.1173600 VL - 54 IS - 5 SP - 575 EP - 580 PB - Taylor & Francis CY - London ER - TY - JOUR A1 - Cheenakula, Dheeraja A1 - Griebel, Kai A1 - Montag, David A1 - Grömping, Markus ED - Huang, Xiaowu T1 - Concept development of a mainstream deammonification and comparison with conventional process in terms of energy, performance and economical construction perspectives JF - Frontiers in Microbiology N2 - Deammonification for nitrogen removal in municipal wastewater in temperate and cold climate zones is currently limited to the side stream of municipal wastewater treatment plants (MWWTP). This study developed a conceptual model of a mainstream deammonification plant, designed for 30,000 P.E., considering possible solutions corresponding to the challenging mainstream conditions in Germany. In addition, the energy-saving potential, nitrogen elimination performance and construction-related costs of mainstream deammonification were compared to a conventional plant model, having a single-stage activated sludge process with upstream denitrification. The results revealed that an additional treatment step by combining chemical precipitation and ultra-fine screening is advantageous prior the mainstream deammonification. Hereby chemical oxygen demand (COD) can be reduced by 80% so that the COD:N ratio can be reduced from 12 to 2.5. Laboratory experiments testing mainstream conditions of temperature (8–20°C), pH (6–9) and COD:N ratio (1–6) showed an achievable volumetric nitrogen removal rate (VNRR) of at least 50 gN/(m3∙d) for various deammonifying sludges from side stream deammonification systems in the state of North Rhine-Westphalia, Germany, where m3 denotes reactor volume. Assuming a retained Norganic content of 0.0035 kgNorg./(P.E.∙d) from the daily loads of N at carbon removal stage and a VNRR of 50 gN/(m3∙d) under mainstream conditions, a resident-specific reactor volume of 0.115 m3/(P.E.) is required for mainstream deammonification. This is in the same order of magnitude as the conventional activated sludge process, i.e., 0.173 m3/(P.E.) for an MWWTP of size class of 4. The conventional plant model yielded a total specific electricity demand of 35 kWh/(P.E.∙a) for the operation of the whole MWWTP and an energy recovery potential of 15.8 kWh/(P.E.∙a) through anaerobic digestion. In contrast, the developed mainstream deammonification model plant would require only a 21.5 kWh/(P.E.∙a) energy demand and result in 24 kWh/(P.E.∙a) energy recovery potential, enabling the mainstream deammonification model plant to be self-sufficient. The retrofitting costs for the implementation of mainstream deammonification in existing conventional MWWTPs are nearly negligible as the existing units like activated sludge reactors, aerators and monitoring technology are reusable. However, the mainstream deammonification must meet the performance requirement of VNRR of about 50 gN/(m3∙d) in this case. KW - anammox KW - energy efficiency KW - mainstream deammonification KW - nitrogen elimination KW - wastewater Y1 - 2023 U6 - https://doi.org/10.3389/fmicb.2023.1155235 SN - 1664-302X VL - 14 IS - 11155235 SP - 1 EP - 15 PB - Frontiers ER - TY - JOUR A1 - Cheenakula, Dheeraja A1 - Hoffstadt, Kevin A1 - Krafft, Simone A1 - Reinecke, Diana A1 - Klose, Holger A1 - Kuperjans, Isabel A1 - Grömping, Markus T1 - Anaerobic digestion of algal–bacterial biomass of an Algal Turf Scrubber system JF - Biomass Conversion and Biorefinery N2 - This study investigated the anaerobic digestion of an algal–bacterial biofilm grown in artificial wastewater in an Algal Turf Scrubber (ATS). The ATS system was located in a greenhouse (50°54′19ʺN, 6°24′55ʺE, Germany) and was exposed to seasonal conditions during the experiment period. The methane (CH4) potential of untreated algal–bacterial biofilm (UAB) and thermally pretreated biofilm (PAB) using different microbial inocula was determined by anaerobic batch fermentation. Methane productivity of UAB differed significantly between microbial inocula of digested wastepaper, a mixture of manure and maize silage, anaerobic sewage sludge, and percolated green waste. UAB using sewage sludge as inoculum showed the highest methane productivity. The share of methane in biogas was dependent on inoculum. Using PAB, a strong positive impact on methane productivity was identified for the digested wastepaper (116.4%) and a mixture of manure and maize silage (107.4%) inocula. By contrast, the methane yield was significantly reduced for the digested anaerobic sewage sludge (50.6%) and percolated green waste (43.5%) inocula. To further evaluate the potential of algal–bacterial biofilm for biogas production in wastewater treatment and biogas plants in a circular bioeconomy, scale-up calculations were conducted. It was found that a 0.116 km2 ATS would be required in an average municipal wastewater treatment plant which can be viewed as problematic in terms of space consumption. However, a substantial amount of energy surplus (4.7–12.5 MWh a−1) can be gained through the addition of algal–bacterial biomass to the anaerobic digester of a municipal wastewater treatment plant. Wastewater treatment and subsequent energy production through algae show dominancy over conventional technologies. KW - Biogas KW - Methane KW - Algal Turf Scrubber KW - Algal–bacterial bioflm KW - Circular bioeconomy Y1 - 2022 U6 - https://doi.org/10.1007/s13399-022-03236-z SN - 2190-6823 N1 - Corresponding author: Dheeraja Cheenakula VL - 13 SP - 15 Seiten PB - Springer CY - Berlin ER - TY - JOUR A1 - Cheenakula, Dheeraja A1 - Paulsen, Svea A1 - Ott, Fabian A1 - Grömping, Markus T1 - Operational window of a deammonifying sludge for mainstream application in a municipal wastewater treatment plant JF - Water and Environment Journal N2 - The present work aimed to study the mainstream feasibility of the deammonifying sludge of side stream of municipal wastewater treatment plant (MWWTP) in Kaster, Germany. For this purpose, the deammonifying sludge available at the side stream was investigated for nitrogen (N) removal with respect to the operational factors temperature (15–30°C), pH value (6.0–8.0) and chemical oxygen demand (COD)/N ratio (≤1.5–6.0). The highest and lowest N-removal rates of 0.13 and 0.045 kg/(m³ d) are achieved at 30 and 15°C, respectively. Different conditions of pH and COD/N ratios in the SBRs of Partial nitritation/anammox (PN/A) significantly influenced both the metabolic processes and associated N-removal rates. The scientific insights gained from the current work signifies the possibility of mainstream PN/A at WWTPs. The current study forms a solid basis of operational window for the upcoming semi-technical trails to be conducted prior to the full-scale mainstream PN/A at WWTP Kaster and WWTPs globally. KW - Anammox KW - Mainstream KW - Nitrogen removal KW - Partial nitritation KW - Wastewater Y1 - 2023 U6 - https://doi.org/10.1111/wej.12898 SN - 1747-6593 N1 - Corresponding author: Dheeraja Cheenakula VL - 38 IS - 1 SP - 59 EP - 70 PB - Wiley CY - Chichester ER - TY - JOUR A1 - Demny, Andreas A1 - Hebel, Christoph T1 - Rechnergestützte Ermittlung der Verbindungsfunktionsstufen und der verbindungsbezogenen Angebotsqualität nach den Richtlinien für integrierte Netzgestaltung nach RIN 2008 JF - Straßenverkehrstechnik : Organ der Forschungsgesellschaft für Straßen- und Verkehrswesen, der Bundesvereinigung der Straßenbau- und Verkehrsingenieure und der Österreichischen Forschungsgesellschaft Straße und Verkehr ; Zeitschrift für Verkehrsplanung, Verkehrsmanagement, Verkehrssicherheit, Verkehrstechnik Y1 - 2014 SN - 0039-2219 VL - Jg. 58 IS - H. 12 SP - 811 EP - 820 PB - Kirschbaum Verlag CY - Bonn ER - TY - JOUR A1 - Dienst, Karl-Jakob T1 - Bewegungsgruppen projektiv-metrischer Ebenen von Char. 2 JF - Journal für die reine und angewandte Mathematik Y1 - 1971 SN - 0075-4102 U6 - https://doi.org/10.1515/crll.1971.250.130 VL - 250 SP - 130 EP - 140 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Dienst, Karl-Jakob T1 - Schnitt- und Zykelgeometrien JF - Geometriae Dedicata (1977) Y1 - 1977 N1 - zugl.: Darmstadt, Techn. Hochsch., Fachbereich 04 - Mathematik, Habil.-Schr., 1975. SP - 23 EP - 54 ER - TY - JOUR A1 - Dienst, Karl-Jakob A1 - Ott, Udo T1 - Spezielle nichtkommutative pappussche affine zweiseitige Inzidenzgruppen JF - Archiv der Mathematik Y1 - 1972 SN - 0003-889X U6 - https://doi.org/10.1007/BF01304890 VL - 23 IS - 1 SP - 329 EP - 336 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Döring, Bernd A1 - Feldmann, Markus A1 - Kuhnhenne, Markus T1 - Der Beitrag von Profilblechdecken zur passiven Kühlung JF - Bauphysik Y1 - 2009 SN - 1437-0980 (E-Journal); 0171-5445 (Print) N1 - Printausg. in der Bibliothek Bayernallee vorhanden: 13 Z 435 VL - Vol. 31 IS - Iss. 2 SP - 65 EP - 71 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Döring, Bernd A1 - Feldmann, Markus A1 - Kuhnhenne, Markus A1 - Müller, Dirk T1 - Phasenwechselmaterial im Metallleichtbau zur Optimierung von Energieeffizienz und sommerlicher Raumtemperatur JF - Stahlbau Y1 - 2011 SN - 1437-1049 (E-Journal); 0038-9145 (Print) VL - Vol. 80 IS - Iss. 9 SP - 666 EP - 672 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Döring, Bernd A1 - Hechler, O. A1 - Weber, F. A1 - Sedlacek, Gerhard T1 - Thermische Aktivierung von Fertigteildecken JF - HLH Lüftung/Klima, Heizung/Sanitär, Gebäudetechnik Y1 - 2004 SN - 1436-5103 N1 - Printausg. in der Bibliothek Bayernallee vorhanden: 13 Z 739 VL - Jg. 55 IS - Nr. 5 SP - 24 EP - 35 ER - TY - JOUR A1 - Döring, Bernd A1 - Kendrick, C. A1 - Lawson, R. M. T1 - Thermal capacity of composite floor slabs JF - Energy and buildings Y1 - 2013 SN - 1872-6178 (E-Journal); 0378-7788 (Print) VL - Vol. 67 SP - 531 EP - 539 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Döring, Bernd A1 - Kuhnhenne, Markus A1 - Hellberg, Jan A1 - Feldmann, Markus T1 - Aktive und passive Temperierung eines Stahldeckensystems : thermische Bauteilaktivierung : numerische und messtechnische Untersuchungen. T. 2. JF - HLH Lüftung/Klima, Heizung/Sanitär, Gebäudetechnik Y1 - 2008 SN - 1436-5103 N1 - Printausg. in der Bibliothek Bayernallee vorhanden: 13 Z 739 VL - Bd. 59 IS - H. 11 SP - 37 EP - 41 ER - TY - JOUR A1 - Döring, Bernd A1 - Kuhnhenne, Markus A1 - Hellberg, Jan A1 - Feldmann, Markus T1 - Aktive und passive Temperierung eines Stahldeckensystems : numerische und messtechnische Untersuchungen. T. 1 JF - HLH : Lüftung, Klima, Heizung, Sanitär, Gebäudetechnik Y1 - 2008 SN - 1436-5103, 0017-9906, 1434-422X, 1436-5103 N1 - Printausg. in der Bibliothek Bayernallee vorhanden: 13 Z 739 VL - Bd. 59 IS - H. 10 SP - 54 EP - 60 ER - TY - JOUR A1 - Döring, Bernd A1 - Reger, Vitali A1 - Kuhnhenne, Markus A1 - Feldmann, Markus A1 - Kesti, Jyrki A1 - Lawson, Mark A1 - Botti, Andrea T1 - Steel solutions for enabling zero-energy buildings JF - Steel Construction - Design and Research Y1 - 2015 U6 - https://doi.org/10.1002/stco.201510029 SN - 1867-0539 N1 - The 13th Nordic Steel Construction Conference, Tampere, 2015 (NSCC-2015) VL - 8 IS - 3 SP - 194 EP - 200 PB - Ernst & Sohn CY - Berlin ER - TY - JOUR A1 - Egner, Ralf A1 - Heyde, Stefan A1 - Laumann, Jörg A1 - Prokop, Ines T1 - Vorschläge für eine anwenderfreundliche und praxistaugliche Novellierung der allgemeinen Bemessungsregeln und Regeln für den Hochbau (EN 1993 Teil 1-1) JF - Stahlbau Y1 - 2015 U6 - https://doi.org/10.1002/stab.201510321 SN - 1437-1049 VL - 84 IS - 10 SP - 811 EP - 822 PB - Ernst & Sohn CY - Berlin ER - TY - JOUR A1 - Emig, J. A1 - Hebel, Christoph A1 - Schwark, A. T1 - Einsatzbereiche für Verkehrsnachfragemodelle JF - Straßenverkehrstechnik N2 - In der Praxis bestehen vielfältige Einsatzbereiche für Verkehrsnachfragemodelle. Mit ihnen können Kenngrößen des Verkehrsangebots und der Verkehrsnachfrage für den heutigen Zustand wie auch für zukünftige Zustände bereitgestellt werden, um so die Grundlagen für verkehrsplanerische Entscheidungen zu liefern. Die neuen „Empfehlungen zum Einsatz von Verkehrsnachfragemodellen für den Personenverkehr“ (EVNM-PV) (FGSV 2022) veranschaulichen anhand von typischen Planungsaufgaben, welche differenzierten Anforderungen daraus für die Modellkonzeption und -erstellung resultieren. Vor dem Hintergrund der konkreten Aufgabenstellung sowie deren spezifischer planerischer Anforderungen bildet die abzuleitende Modellspezifikation die verabredete Grundlage zwischen Auftraggeber und Modellersteller für die konkrete inhaltliche, fachliche Ausgestaltung des Verkehrsmodells. Y1 - 2022 U6 - https://doi.org/10.53184/SVT10-2022-2 SN - 0039-2219 VL - 66 IS - 10 SP - 727 EP - 736 PB - Kirschbaum Verlag GmbH CY - Bonn ER -