@article{RoehlenPilasSchoeningetal.2017,
  author    = {R{\"o}hlen, Desiree and Pilas, Johanna and Sch{\"o}ning, Michael Josef and Selmer, Thorsten},
  title     = {Development of an amperometric biosensor platform for the combined determination of l-Malic, Fumaric, and l-Aspartic acid},
  series = {Applied Biochemistry and Biotechnology},
  volume    = {183},
  journal   = {Applied Biochemistry and Biotechnology},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {1559-0291},
  doi       = {10.1007/s12010-017-2578-1},
  pages     = {566 -- 581},
  year      = {2017},
  abstract  = {Three amperometric biosensors have been developed for the detection of L-malic acid, fumaric acid, and L -aspartic acid, all based on the combination of a malate-specific dehydrogenase (MDH, EC 1.1.1.37) and diaphorase (DIA, EC 1.8.1.4). The stepwise expansion of the malate platform with the enzymes fumarate hydratase (FH, EC 4.2.1.2) and aspartate ammonia-lyase (ASPA, EC 4.3.1.1) resulted in multi-enzyme reaction cascades and, thus, augmentation of the substrate spectrum of the sensors. Electrochemical measurements were carried out in presence of the cofactor β-nicotinamide adenine dinucleotide (NAD+) and the redox mediator hexacyanoferrate (III) (HCFIII). The amperometric detection is mediated by oxidation of hexacyanoferrate (II) (HCFII) at an applied potential of + 0.3 V vs. Ag/AgCl. For each biosensor, optimum working conditions were defined by adjustment of cofactor concentrations, buffer pH, and immobilization procedure. Under these improved conditions, amperometric responses were linear up to 3.0 mM for L-malate and fumarate, respectively, with a corresponding sensitivity of 0.7 μA mM-1 (L-malate biosensor) and 0.4 μA mM-1 (fumarate biosensor). The L-aspartate detection system displayed a linear range of 1.0-10.0 mM with a sensitivity of 0.09 μA mM-1. The sensor characteristics suggest that the developed platform provides a promising method for the detection and differentiation of the three substrates.},
  language  = {en}
}
@article{RoehlenPilasDahmenetal.2018,
  author    = {R{\"o}hlen, Desiree and Pilas, Johanna and Dahmen, Markus and Keusgen, Michael and Selmer, Thorsten and Sch{\"o}ning, Michael Josef},
  title     = {Toward a Hybrid Biosensor System for Analysis of Organic and Volatile Fatty Acids in Fermentation Processes},
  series = {Frontiers in Chemistry},
  journal   = {Frontiers in Chemistry},
  number    = {6},
  publisher = {Frontiers},
  address   = {Lausanne},
  doi       = {10.3389/fchem.2018.00284},
  pages     = {Artikel 284},
  year      = {2018},
  abstract  = {Monitoring of organic acids (OA) and volatile fatty acids (VFA) is crucial for the control of anaerobic digestion. In case of unstable process conditions, an accumulation of these intermediates occurs. In the present work, two different enzyme-based biosensor arrays are combined and presented for facile electrochemical determination of several process-relevant analytes. Each biosensor utilizes a platinum sensor chip (14 × 14 mm²) with five individual working electrodes. The OA biosensor enables simultaneous measurement of ethanol, formate, d- and l-lactate, based on a bi-enzymatic detection principle. The second VFA biosensor provides an amperometric platform for quantification of acetate and propionate, mediated by oxidation of hydrogen peroxide. The cross-sensitivity of both biosensors toward potential interferents, typically present in fermentation samples, was investigated. The potential for practical application in complex media was successfully demonstrated in spiked sludge samples collected from three different biogas plants. Thereby, the results obtained by both of the biosensors were in good agreement to the applied reference measurements by photometry and gas chromatography, respectively. The proposed hybrid biosensor system was also used for long-term monitoring of a lab-scale biogas reactor (0.01 m³) for a period of 2 months. In combination with typically monitored parameters, such as gas quality, pH and FOS/TAC (volatile organic acids/total anorganic carbonate), the amperometric measurements of OA and VFA concentration could enhance the understanding of ongoing fermentation processes.},
  language  = {en}
}
@article{RuppSchulzeKuperjans2018,
  author    = {Rupp, Matthias and Schulze, Sven and Kuperjans, Isabel},
  title     = {Comparative life cycle analysis of conventional and hybrid heavy-duty trucks},
  series = {World electric vehicle journal},
  volume    = {9},
  journal   = {World electric vehicle journal},
  number    = {2},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2032-6653},
  doi       = {10.3390/wevj9020033},
  pages     = {Article No. 33},
  year      = {2018},
  abstract  = {Heavy-duty trucks are one of the main contributors to greenhouse gas emissions in German traffic. Drivetrain electrification is an option to reduce tailpipe emissions by increasing energy conversion efficiency. To evaluate the vehicle's environmental impacts, it is necessary to consider the entire life cycle. In addition to the daily use, it is also necessary to include the impact of production and disposal. This study presents the comparative life cycle analysis of a parallel hybrid and a conventional heavy-duty truck in long-haul operation. Assuming a uniform vehicle glider, only the differing parts of both drivetrains are taken into account to calculate the environmental burdens of the production. The use phase is modeled by a backward simulation in MATLAB/Simulink considering a characteristic driving cycle. A break-even analysis is conducted to show at what mileage the larger CO2eq emissions due to the production of the electric drivetrain are compensated. The effect of parameter variation on the break-even mileage is investigated by a sensitivity analysis. The results of this analysis show the difference in CO2eq/t km is negative, indicating that the hybrid vehicle releases 4.34 g CO2eq/t km over a lifetime fewer emissions compared to the diesel truck. The break-even analysis also emphasizes the advantages of the electrified drivetrain, compensating the larger emissions generated during production after already a distance of 15,800 km (approx. 1.5 months of operation time). The intersection coordinates, distance, and CO2eq, strongly depend on fuel, emissions for battery production and the driving profile, which lead to nearly all parameter variations showing an increase in break-even distance.},
  language  = {en}
}
@article{RuppRiekeHandschuhetal.2020,
  author    = {Rupp, Matthias and Rieke, Christian and Handschuh, Nils and Kuperjans, Isabel},
  title     = {Economic and ecological optimization of electric bus charging considering variable electricity prices and CO₂eq intensities},
  series = {Transportation Research Part D: Transport and Environment},
  volume    = {81},
  journal   = {Transportation Research Part D: Transport and Environment},
  number    = {Article 102293},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1361-9209},
  doi       = {10.1016/j.trd.2020.102293},
  year      = {2020},
  abstract  = {In many cities, diesel buses are being replaced by electric buses with the aim of reducing local emissions and thus improving air quality. The protection of the environment and the health of the population is the highest priority of our society. For the transport companies that operate these buses, not only ecological issues but also economic issues are of great importance. Due to the high purchase costs of electric buses compared to conventional buses, operators are forced to use electric vehicles in a targeted manner in order to ensure amortization over the service life of the vehicles. A compromise between ecology and economy must be found in order to both protect the environment and ensure economical operation of the buses. In this study, we present a new methodology for optimizing the vehicles' charging time as a function of the parameters CO₂eq emissions and electricity costs. Based on recorded driving profiles in daily bus operation, the energy demands of conventional and electric buses are calculated for the passenger transportation in the city of Aachen in 2017. Different charging scenarios are defined to analyze the influence of the temporal variability of CO₂eq intensity and electricity price on the environmental impact and economy of the bus. For every individual day of a year, charging periods with the lowest and highest costs and emissions are identified and recommendations for daily bus operation are made. To enable both the ecological and economical operation of the bus, the parameters of electricity price and CO₂ are weighted differently, and several charging periods are proposed, taking into account the priorities previously set. A sensitivity analysis is carried out to evaluate the influence of selected parameters and to derive recommendations for improving the ecological and economic balance of the battery-powered electric vehicle. In all scenarios, the optimization of the charging period results in energy cost savings of a maximum of 13.6\% compared to charging at a fixed electricity price. The savings potential of CO₂eq emissions is similar, at 14.9\%. From an economic point of view, charging between 2 a.m. and 4 a.m. results in the lowest energy costs on average. The CO₂eq intensity is also low in this period, but midday charging leads to the largest savings in CO₂eq emissions. From a life cycle perspective, the electric bus is not economically competitive with the conventional bus. However, from an ecological point of view, the electric bus saves on average 37.5\% CO₂eq emissions over its service life compared to the diesel bus. The reduction potential is maximized if the electric vehicle exclusively consumes electricity from solar and wind power.},
  language  = {en}
}
@article{RuppHandschuhRiekeetal.2019,
  author    = {Rupp, Matthias and Handschuh, Nils and Rieke, Christian and Kuperjans, Isabel},
  title     = {Contribution of country-specific electricity mix and charging time to environmental impact of battery electric vehicles: A case study of electric buses in Germany},
  series = {Applied Energy},
  volume    = {237},
  journal   = {Applied Energy},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0306-2619},
  doi       = {10.1016/j.apenergy.2019.01.059},
  pages     = {618 -- 634},
  year      = {2019},
  language  = {en}
}
@inproceedings{RousseauKern2014,
  author    = {Rousseau, Alain and Kern, Alexander},
  title     = {How to deal with environmental risk in IEC 62305-2},
  series = {2014 International Conference on Lightning Protection (ICLP), Shanghai, China},
  booktitle = {2014 International Conference on Lightning Protection (ICLP), Shanghai, China},
  organization    = {International Conference on Lightning Protection <2014, Shanghai>},
  pages     = {521 -- 527},
  year      = {2014},
  abstract  = {The 2nd edition of the lightning risk management standard (IEC 62305-2) considers structures, which may endanger environment. In these cases, the loss is not limited to the structure itself, which is valid for usual structures. In the past (Edition 1) this danger was simply taken into account by a special hazard factor, multiplying the existing risk for the structure with a number. Now, in the edition 2, we add to the risk for the structure itself a "second risk" due to the losses outside the structure. The losses outside can be treated independently from what occurs inside. This is a major advantage to analyze the risk for sensitive structures, like chemical plants, nuclear plants, or structures containing explosives, etc. In this paper, the existing procedure given by the European version EN 62305-2 Ed.2 is further developed and applied to a few structures.},
  language  = {en}
}
@misc{RothkranzKrafftTippkoetter2022,
  author    = {Rothkranz, Berit and Krafft, Simone and Tippk{\"o}tter, Nils},
  title     = {Media optimization for sustainable fuel production: How to produce biohydrogen from renewable resources with Thermotoga neapolitana},
  series = {Chemie Ingenieur Technik},
  volume    = {94},
  journal   = {Chemie Ingenieur Technik},
  number    = {9},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0009-286X},
  doi       = {10.1002/cite.202255305},
  pages     = {1298 -- 1299},
  year      = {2022},
  abstract  = {Hydrogen is playing an increasingly important role in research and politics as an energy carrier of the future. Since hydrogen has commonly been produced from methane by steam reforming, the need for climate-friendly, alternative production routes is emerging. In addition to electrolysis, fermentative routes for the production of so-called biohydrogen are "green" alternatives. The application of microorganisms offers the advantage of sustainable production from renewable resources using easily manageable technologies. In this project, the hyperthermophilic, anaerobic microorganism Thermotoga neapolitana is used for the productio nof biohydrogen from renewable resources. The enzymatically hydrolyzed resources were used in fermentation leading to yield coefficients of 1.8 mole H₂ per mole glucose when using hydrolyzed straw and ryegrass supplemented with medium, respectively. These results are similar to the hydrogen yields when using Thermotoga basal medium with glucose (TBGY) as control group. In order to minimize the supplementation of the hydrolysate and thus increase the economic efficiency of the process, the essential media components were identified. The experiments revealed NaCl, KCl, and glucose as essential components for cell growth as well as biohydrogen production. When excluding NaCl, a decrease of 96\% in hydrogen production occured.},
  language  = {en}
}
@article{RothTippkoetter2016,
  author    = {Roth, Jasmine and Tippk{\"o}tter, Nils},
  title     = {Evaluation of lignocellulosic material for butanol production using enzymatic hydrolysate medium},
  series = {Cellulose Chemistry and Technology},
  volume    = {50},
  journal   = {Cellulose Chemistry and Technology},
  number    = {3-4},
  publisher = {Editura Academiei Romane},
  address   = {Bukarest},
  pages     = {405 -- 410},
  year      = {2016},
  abstract  = {Butanol is a promising gasoline additive and platform chemical that can be readily produced via acetone-butanolethanol (ABE) fermentation from pretreated lignocellulosic materials. This article examines lignocellulosic material from beech wood for ABE fermentation, using Clostridium acetobutylicum. First, the utilization of both C₅₋ (xylose) and C₆₋ (glucose) sugars as sole carbon source was investigated in static cultivation, using serum bottles and synthetic medium. The utilization of pentose sugar resulted in a solvent yield of 0.231 g·g_sugar⁻¹, compared to 0.262 g·g_sugar⁻¹ using hexose. Then, the Organosolv pretreated crude cellulose fibers (CF) were enzymatically decomposed, and the resulting hydrolysate medium was analyzed for inhibiting compounds (furans, organic acids, phenolics) and treated with ionexchangers for detoxification. Batch fermentation in a bioreactor using CF hydrolysate medium resulted in a total solvent yield of 0.20 gABE·g_sugar⁻¹.},
  language  = {en}
}
@misc{RothTippkoetter2016,
  author    = {Roth, J. and Tippk{\"o}tter, Nils},
  title     = {New Approach for Enzymatic Hydrolysis of Lignocellulose with Selective Diffusion Separation of the Monosaccharide Products},
  series = {Chemie Ingenieur Technik},
  volume    = {88},
  journal   = {Chemie Ingenieur Technik},
  number    = {9},
  publisher = {Wiley-VCH},
  address   = {Weinheim},
  issn      = {0009-286X},
  doi       = {10.1002/cite.201650301},
  pages     = {1237},
  year      = {2016},
  abstract  = {Enzymatic hydrolysis of lignocellulosic material plays an important role in the classical biorefinery approach. Apart from the pretreatment of the raw material, hydrolysis is the basis for the conversion of the cellulose and hemicellulose fraction into fermentable sugars. After hydrolysis, usually a solid-liquid separation takes place, in order to separate the residual plant material from the sugar-rich fraction, which can be subsequently used in a fermentation step. In order to factor out the separation step, the usage of in alginate immobilized crude cellulose fiber beads (CFBs) were evaluated. Pretreated cellulose fibers are incorporated in an alginate matrix together with the relevant enzymes. In doing so, sugars diffuse trough the alginate matrix, allowing a simplified delivery into the surrounding fluid. This again reduces product inhibition of the glucose on the enzyme catalysts. By means of standardized bead production the hydrolysis in lab scale was possible. First results show that liberation of glucose and xylose is possible, allowing a maximum total sugar yield of 75 \%.},
  language  = {en}
}
@inproceedings{RothMoehringTippkoetter2016,
  author    = {Roth, J. and M{\"o}hring, S. and Tippk{\"o}tter, Nils},
  title     = {Characterization and evaluation of lignocellulosic biomass 130 hydrolysates for ABE fermentation},
  series = {New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany},
  booktitle = {New frontiers of biotech-processes (Himmelfahrtstagung) : 02-04 May 2016, Rhein-Mosel-Halle, Koblenz/Germany},
  publisher = {DECHEMA},
  address   = {Frankfurt am Main},
  pages     = {130},
  year      = {2016},
  language  = {en}
}