@misc{ReiterSenguelMaietal., author = {Reiter, Sebastian and Seng{\"u}l, Akant and Mai, Christian and Spirito, Davide and Wenger, Christian and Fischer, Inga Anita}, title = {On-chip refractive index sensors based on plasmonic TiN Nanohole Arrays}, series = {2024 IEEE Silicon Photonics Conference (SiPhotonics)}, journal = {2024 IEEE Silicon Photonics Conference (SiPhotonics)}, isbn = {979-8-3503-9404-7}, issn = {1949-209X}, doi = {10.1109/SiPhotonics60897.2024.10544048}, pages = {2}, language = {de} } @misc{JoseMaiWengeretal., author = {Jose, Josmy and Mai, Christian and Wenger, Christian and Fischer, Inga Anita}, title = {Integration concept of plasmonic TiN nanohole arrays in a 200 mm BiCMOS Si technology for refractive index sensor applications}, series = {iCCC2024 - iCampµs Cottbus Conference}, journal = {iCCC2024 - iCampµs Cottbus Conference}, doi = {10.5162/iCCC2024/7.2}, pages = {96 -- 99}, language = {de} } @misc{MaiPeczekKrohetal., author = {Mai, Christian and Peczek, Anna and Kroh, Aleksandra and Jose, Josmy and Reiter, Sebastian and Wenger, Christian and Fischer, Inga Anita}, title = {Towards a CMOS compatible refractive index sensor: cointegration of TiN nanohole arrays and Ge photodetectors in a 200 mm wafer silicon technology}, series = {Optics Express}, volume = {32}, journal = {Optics Express}, number = {17}, publisher = {Optica Publishing Group}, issn = {1094-4087}, doi = {10.1364/OE.530081}, pages = {29099 -- 29111}, abstract = {In this work, we present the monolithic integration of a TiN nanohole array and a Ge photodetector towards a CMOS compatible fabrication of a refractive index sensor in a 200 mm wafer silicon technology. We developed a technology process that enables fabrication with high yields of around 90\%. Ge photodetectors with a Ge layer thickness of 450 nm and an area of 1600 µm2 (40 µm x 40 µm) show dark current densities of around 129 mA/cm2 and responsivities of 0.114 A/W measured by top illumination (TE polarization; λ = 1310 nm; angle of incidence = 14 °) at a reverse bias of 1 V. Nanohole arrays were structured in a 150 nm thick TiN layer. They were integrated into the back end of line and placed spatially close to the Ge photodetectors. After the metallization, passivation, and pad opening, the nanohole arrays were released with the help of an amorphous silicon stop layer. A significant impact of the TiN nanohole arrays on the optical behavior of the photodetector could be proven on the wafer level. Photocurrent measurements by top illumination confirm a strong dependence of optical properties on the polarization of the incident light and the nanohole array design. We demonstrate very stable photocurrents on the wafer level with a standard deviation of σ \< 6\%.}, language = {en} } @misc{DerschRoemerPerezetal., author = {Dersch, Nadine and Roemer, Christian and Perez, Eduardo and Wenger, Christian and Schwarz, Mike and I{\~n}{\´i}guez, Benjam{\´i}n and Kloes, Alexander}, title = {Fast circuit simulation of memristive crossbar arrays with bimodal stochastic synaptic weights}, series = {2024 IEEE Latin American Electron Devices Conference (LAEDC)}, journal = {2024 IEEE Latin American Electron Devices Conference (LAEDC)}, publisher = {IEEE}, isbn = {979-8-3503-6130-8}, issn = {979-8-3503-6129-2}, doi = {10.1109/LAEDC61552.2024.10555829}, pages = {1 -- 4}, abstract = {This paper presents an approach for highly efficient circuit simulation of hardware-based artificial neural networks by using memristive crossbar array architectures. There are already possibilities to test neural networks with stochastic weights via simulations like the macro model NeuroSim. However, the noise-based variability approach offers more realistic setting options including elements of a classical circuit simulation for more precise analysis of neural networks. With this approach, statistical parameter fluctuations can be simulated based on different distribution functions of devices. In Cadence Virtuoso, a simulation of a crossbar array with 10 synaptic weights following a bimodal distribution, the new approach shows a 1,000x speedup compared to a Monte Carlo simulation. Initial tests of a memristive crossbar array with over 15,000 stochastic weights to classify the MNIST dataset show that the new approach can be used to test the functionality of hardware-based neural networks.}, language = {en} } @misc{KleinNadolskiZenkeretal., author = {Klein, Rupert and Nadolski, Maikel and Zenker, Christian and Oevermann, Michael and Paschereit, Christian Oliver}, title = {Pressure gain combustion for gas turbines : analysis of a fully coupled engine model}, series = {Journal of Engineering for Gas Turbines and Power}, volume = {147}, journal = {Journal of Engineering for Gas Turbines and Power}, number = {2}, publisher = {ASME International}, issn = {0742-4795}, doi = {10.1115/1.4066348}, pages = {26}, abstract = {The "Shockless Explosion Combustion" (SEC) concept for gas turbine combustors, introduced in 2014, approximates constant volume combustion (CVC) by harnessing acoustic confinement of auto-igniting gas packets. The resulting pressure waves simultaneously transmit combustion energy to a turbine plenum and facilitate the combustor's recharging against an average pressure gain. Challenges in actualizing an SEC-driven gas turbine include (i) the creation of charge stratifications for nearly homogeneous auto-ignition, (ii) protecting the turbocomponents from combustion-induced pressure fluctuations, (iii) providing evidence that efficiency gains comparable to those of CVC over deflagrative combustion can be realized, and (iv) designing an effective one-way intake valve. This work addresses challenges (i)-(iii) utilizing computational engine models incorporating a quasi-one-dimensional combustor, zero- and two-dimensional (2D) compressor and turbine plena, and quasi-stationary turbocomponents. Two SEC operational modes are identified which fire at roughly one and two times the combustors' acoustic frequencies. Results for SEC-driven gas turbines with compressor pressure ratios of 6:1 and 20:1 reveal 1.5-fold mean pressure gains across the combustors. Assuming ideally efficient compressors and turbines, efficiency gains over engines with deflagration-based combustors of 30\% and 18\% are realized, respectively. With absolute values of 52\% and 66\%, the obtained efficiencies are close to the theoretical Humphrey cycle efficiencies of 54\% and 65\% for the mentioned precompression ratios. Detailed thermodynamic cycle analyses for individual gas parcels suggest that there is room for further efficiency gains through optimized plenum and combustor designs.}, language = {en} } @misc{JinksBottovanBemdenBunzlietal., author = {Jinks, Clare and Botto-van Bemden, Angie and Bunzli, Samantha and Bowden, Jocelyn and Egerton, Thorlene and Eyles, Jillian and Foster, Nadine and Healey, Emma L. and Maddison, John and O'Brien, Daniel and Quicke, Jonathan G. and Schiphof, Dieuwke and Parry, Emma and Thomas, Martin J. and Holden, Melanie A. and Allen, Kelli and Babatunde, Opeyemi O. and Bennel, Kim L. and Berry, Alice and Bierma-Zeinstra, Sita and Callahan, Leigh and Campbell, Laura and Dziedzic, Krysia S. and Finney, Andrew and French, Helen P. and Haber, Travis and Hadley-Barrows, Tina and Hall, Michelle and Hawker, Gillian and Henriksen, Marius and Hinman, Rana S. and Ho-Pham, Lan and Hunter, David J. and Lawford, Belinda J. and Mallen, Christian D. and McHugh, Gretl A. and Kopkow, Christian and Neogi, Tuhina and Nicholls, Elaine and Nicolson, Philippa J. A. and {\O}ster{\aa}s, Nina and Paskins, Zoe and Protheroe, Joanne and Roos, Ewa M. and Runhaar, Jos and Skou, Soren T. and Simkins, Joanna and Swaithes, Laura and Thomas, Geraint and Esch, Martin van der and Whittaker, Jackie and Zhang, Weiya}, title = {Changing the narrative on osteoarthritis: A call for global action}, series = {Osteoarthritis and Cartilage}, volume = {32}, journal = {Osteoarthritis and Cartilage}, number = {4}, issn = {1063-4584}, doi = {10.1016/j.joca.2024.02.004}, pages = {414 -- 420}, language = {en} } @misc{SchurigUmehHenzeetal., author = {Schurig, Mona and Umeh, Obinna and Henze, Henriette and Jung, Marie Juliane and Gresing, Lennart and Blanchard, Veronique and Maltzahn, Julia von and H{\"u}bner, Christian and Franzka, Patricia}, title = {Consequences of GMPPB deficiency for neuromuscular development and maintenance}, series = {Frontiers in Molecular Neuroscience}, volume = {17}, journal = {Frontiers in Molecular Neuroscience}, issn = {1662-5099}, doi = {10.3389/fnmol.2024.1356326}, abstract = {Guanosine diphosphate-mannose pyrophosphorylase B (GMPPB) catalyzes the conversion of mannose-1-phosphate and GTP to GDP-mannose, which is required as a mannose donor for the biosynthesis of glycan structures necessary for proper cellular functions. Mutations in GMPPB have been associated with variable neuromuscular disorders such as muscular dystrophy and myasthenic syndromes. Here, we report that GMPPB protein abundance increases during brain and skeletal muscle development, which is accompanied by an increase in overall protein mannosylation. To model the human disorder in mice, we generated heterozygous GMPPB KO mice using CRISPR/Cas9. While we were able to obtain homozygous KO mice from heterozygous matings at the blastocyst stage, homozygous KO embryos were absent beyond embryonic day E8.5, suggesting that the homozygous loss of GMPPB results in early embryonic lethality. Since patients with GMPPB loss-of-function manifest with neuromuscular disorders, we investigated the role of GMPPB in vitro. Thereby, we found that the siRNA-mediated knockdown of Gmppb in either primary myoblasts or the myoblast cell line C2C12 impaired myoblast differentiation and resulted in myotube degeneration. siRNA-mediated knockdown of Gmppb also impaired the neuron-like differentiation of N2A cells. Taken together, our data highlight the essential role of GMPPB during development and differentiation, especially in myogenic and neuronal cell types.}, language = {en} } @misc{BundschuhRappelBocketal., author = {Bundschuh, Jana and Rappel, Herbert and Bock, Andreas and Balleisen, Ute and Daiser, Markus and Friedmann, G{\"u}nter and K{\"o}nig, Werner and Miltenberger, Tobias and M{\"u}ller, Manuela and M{\"u}ller, Robert and Poeplau, Norbert and Roosen, Alix and Schlotter, Alexander and Sedlmair, Christian and Weiler, Michael and Thewes, Christoph and Brock, Christopher}, title = {Effects of queen excluders on the colony dynamics of honeybees (Apis mellifera L.) under biodynamic management}, series = {Apidologie}, volume = {55}, journal = {Apidologie}, number = {16}, issn = {1297-9678}, doi = {10.1007/s13592-023-01041-9}, abstract = {The evaluation of beekeeping management practices (BMPs) is important for beekeepers worldwide because their choice affects health and survival of managed honeybee (A. mellifera L.) colonies and touches ethical and economic questions. This study focusses on queen excluders, a common hive addition in contemporary beekeeping. Its impacts are controversially discussed but have not been studied scientifically yet. Within a 4-year participatory on-farm experiment, we assessed the effects on colony dynamics in 64 hives in 8 apiaries during one season in Germany using the Liebefeld estimation method. We found no significant deviation for parameters of colony dynamics between hives managed with and without queen excluders. A qualitative decision-making tool (Pugh decision matrix) facilitated concept selection only for specific beekeepers.}, language = {en} } @misc{Abendroth, author = {Abendroth, Christian}, title = {Zirkul{\"a}re Mikrobiome f{\"u}r Recycling- und R{\"u}ckgewinnungsanwendungen}, series = {Werkstoffe in der Fertigung}, journal = {Werkstoffe in der Fertigung}, number = {1}, issn = {0939-2629}, pages = {27 -- 28}, abstract = {Der Artikel stellt das Fachgebiet der Kreislaufwirtschaft an der BTU vor. Forschungsthemen des Fachgebietes werden kurz erl{\"a}utert. Diese umfassen Biolaugung zur Behandlung von Leiterplatten, anaerobe Fermentation als Multiproduktplattform, Power2Gas Prozesse sowie das Verst{\"a}ndnis mikrobieller Gemeinschaften mit Bedeutung f{\"u}r die Kreislaufwirtschaft.}, language = {de} } @misc{JansenAbendroth, author = {Jansen, Nils and Abendroth, Christian}, title = {Unveiling the Biochar Potential: Lowering Greenhouse Gas Emissions across the Biogas Supply Chain}, series = {Kreislauf und Ressourcenwirtschaft : 13.Wissenschaftskongress : am 15. und 16. Februar 2024 an der Technischen Universit{\"a}t Wien, Tagungsband}, journal = {Kreislauf und Ressourcenwirtschaft : 13.Wissenschaftskongress : am 15. und 16. Februar 2024 an der Technischen Universit{\"a}t Wien, Tagungsband}, editor = {Bockreis, Anke and Faulstich, Martin and Flamme, Sabine and Kranert, Martin and Mocker, Mario and Nelles, Michael and Quicker, Peter and Rettenberger, Gerhard and Rotter, Vera Susanne}, publisher = {Innsbruck university press}, address = {Innsbruck}, isbn = {978-3-99106-120-5}, doi = {10.15203/99106-120-5}, pages = {279 -- 286}, abstract = {The carbon-rich material known as biochar is the product of pyrolysis - a thermochemical conversion of biomass in the absence of oxygen. Given its characteristics, including long-term stability and sorption capacity, biochar has received increasing attention as a promising tool for addressing climate change and enhancing the production of biogas. This work combines both functions by examining, through different application scenarios, the potential role of biochar in mitigating greenhouse gas (GHG) emissions across the biogas supply chain. The wood-derived and high pyrolyzed biochar CarboFerm® was used as an example biochar for application in four different scenarios: (1) Application to soil without fertilizer, (2) application to soil with fertilizer, (3) application to biogas fermenter, (4) application to digestate treatment. The GHG mitigation was calculated by applying the methodology of the Renewable Energy Directive II (RED II). The scenario comparison resulted in GHG mitigation effectiveness of 0.03, 0.01, 0.06, and 0.03 g CO2eq / MJ biogas / t biochar, respectively. Thus, this study recommends using biochar in biogas fermenters and subsequently applying the biochar-enriched digestate to agricultural soil to reduce GHG emissions from biogas production. Furthermore, it is suggested that the mitigation potential of biochar may not be fully recognized in the RED, potentially resulting in an underestimation of its effectiveness.}, language = {en} } @misc{AlipoursarbaniAbendroth, author = {Alipoursarbani, Mozhdeh and Abendroth, Christian}, title = {Aerobic Digestate Reactivation of Anaerobically Digested Sewage Sludge - A Micro Review}, series = {Kreislauf und Ressourcenwirtschaft : 13.Wissenschaftskongress : am 15. und 16. Februar 2024 an der Technischen Universit{\"a}t Wien}, journal = {Kreislauf und Ressourcenwirtschaft : 13.Wissenschaftskongress : am 15. und 16. Februar 2024 an der Technischen Universit{\"a}t Wien}, editor = {Bockreis, Anke and Faulstich, Martin and Flamme, Sabine and Kranert, Martin and Mocker, Mario and Nelles, Michael and Quicker, Peter and Rettenberger, Gerhard and Rotter, Vera Susanne}, publisher = {Innsbruck university press}, address = {Innsbruck}, isbn = {978-3-99106-120-5}, doi = {10.15203/99106-120-5}, pages = {177 -- 180}, abstract = {The authors of the present work summarize their recently published article "Microbiome Characterization after Aerobic Digestate Reactivation of Anaerobically Digested Sewage Sludge" from Otto et al. (2023). This article presents the outcomes of a municipal-scale demonstrator plant implementing a recently patented process for improved sludge degradation within a municipal sewage treatment system. The study focused on a 1500 m³ sewage sludge digester, where an intermediate aerobic sewage sludge reactivation stage was introduced. This reactivation resulted in a 55\% increase in biogas production and a 25\% reduction in residual solids. For the residual NH4 in the liquid phase of the sewage sludge, the process achieved NH4-N removal rates exceeding 90\%. To gain insights into the microbial community dynamics, 16S rRNA gene amplicon high-throughput sequencing was employed on the reactivated digestate. The analysis revealed a reduced population of methane-forming archaea compared to the primary digester, along with the detection of multiple ammonium-oxidizing bacteria. Notably, genera within the Chitinophagaceae family, comprising up to 18.8\% of DNA sequences, were prevalent, alongside a small presence of Candidatus nitrosoglobus (<0.3\%). The study highlights an economically viable approach for efficient nitrogen removal from sewage sludge while simultaneously increasing biogas yields and reducing potential pathogens in the residual material.}, language = {en} } @misc{KnauerSchulzZemellaetal., author = {Knauer, Jan Felix and Schulz, Christian and Zemella, Anne and W{\"u}stenhagen, Doreen A. and Walter, Ruben Magnus and K{\"u}pper, Jan-Heiner and Kubick, Stefan}, title = {Synthesis of mono Cytochrome P450 in a modified CHO-CPR cell-free protein production platform}, series = {Scientific Reports}, volume = {14}, journal = {Scientific Reports}, issn = {2045-2322}, doi = {10.1038/s41598-024-51781-6}, pages = {14}, abstract = {AbstractCytochromes P450 (CYPs) are a group of monooxygenases that can be found in almost all kinds of organisms. For CYPs to receive electrons from co-substrate NADPH, the activity of NADPH-Cytochrome-P450-oxidoreductase (CPR) is required as well. In humans, CYPs are an integral part of liver-based phase-1 biotransformation, which is essential for the metabolization of multiple xenobiotics and drugs. Consequently, CYPs are important players during drug development and therefore these enzymes are implemented in diverse screening applications. For these applications it is usually advantageous to use mono CYP microsomes containing only the CYP of interest. The generation of mono-CYP containing mammalian cells and vesicles is difficult since endogenous CYPs are present in many cell types that contain the necessary co-factors. By obtaining translationally active lysates from a modified CHO-CPR cell line, it is now possible to generate mono CYPs in a cell-free protein synthesis process in a straightforward manner. As a proof of principle, the synthesis of active human CYPs from three different CYP450 gene families (CYP1A2, CYP2B6 and CYP3A4), which are of outstanding interest in industry and academia was demonstrated. Luciferase based activity assays confirm the activity of the produced CYPs and enable the individual adaptation of the synthesis process for efficient cell-free enzyme production. Furthermore, they allow for substrate and inhibitor screenings not only for wild-type CYPs but also for mutants and further CYP isoforms and variants. As an example, the turnover of selected CYP substrates by cell-free synthesized CYPs was demonstrated via an indirect luciferase assay-based screening setup.}, language = {en} } @misc{NitschRatzkePozarowskaetal., author = {Nitsch, Paul-G. and Ratzke, Markus and Pozarowska, Emilia and Flege, Jan Ingo and Alvarado Chavarin, Carlos and Wenger, Christian and Fischer, Inga Anita}, title = {Deposition of reduced ceria thin films by reactive magnetron sputtering for the development of a resistive gas sensor}, series = {Verhandlungen der DPG, Berlin 2024}, journal = {Verhandlungen der DPG, Berlin 2024}, publisher = {Deutsche Physikalische Gesellschaft}, address = {Bad Honnef}, issn = {0420-0195}, abstract = {The use of cerium oxide for hydrogen sensing is limited by the low electrical conductivity of layers deposited from a ceria target. To increase the electrical conductivity, partially reduced cerium oxide layers were obtained from a metallic cerium target by reactive magnetron sputtering. The proportions of the oxidation states Ce3+, present in reduced species, and Ce4+, present in fully oxidized species, were determined by ex-situ XPS. For electrical characterization, films were deposited on planarized tungsten finger electrodes. IV curves were measured over several days to investigate possible influences of oxygen and humidity on electrical conductivity. The morphological stability of the layers under ambient conditions was investigated by microscopical methods. The XPS results show a significant amount of Ce3+ in the layers. The electrical conductivity of as-grown samples is several orders of magnitude higher than that of samples grown from a ceria target. However, the conductivity decreases over time, indicating an oxidation of the layers. The surface morphology of the samples was found to be changing drastically within days, leading to partial delamination.}, language = {en} } @misc{PengDostLukasetal., author = {Peng, Yingying and Dost, Florian and Lukas, Bryan and Homburg, Christian}, title = {Four Types of Information Interplay in Product Reviews and their Sales Effects}, series = {2024 AMA Winter Academic Conference Proceedings}, journal = {2024 AMA Winter Academic Conference Proceedings}, editor = {Cross, Samantha and Saboo, Alok}, isbn = {978-0-87757-018-9}, pages = {604 -- 606}, abstract = {Consumer decision-making is influenced by user-generated information in reviews of products and services. We predict that sales levels are associated with two forms, respectively, of information inconsistency (confliction and competition) and consistency (confirmation and complementary) often found in product and service reviews. For our investigation, we classified information contained in tablet computer reviews as conflicting, competing, confirming, or complementing using BERT (Bidirectional Encoder Representations from Transformers) and word2vec (Word to Vector) techniques. Estimating an aggregated-level sales rank model over a 24-week period on reviews and sales data obtained from Amazon, we show that variations in tablet sales can be partially explained with our information classification. These findings provide new insights for user-generated content research.}, language = {en} } @misc{StrobelAlvaradoChavarinKnautetal., author = {Strobel, Carsten and Alvarado Chavarin, Carlos and Knaut, Martin and V{\"o}lkel, Sandra and Albert, Matthias and Hiess, Andre and Max, Benjamin and Wenger, Christian and Kirchner, Robert and Mikolajick, Thomas}, title = {High Gain Graphene Based Hot Electron Transistor with Record High Saturated Output Current Density}, series = {Advanced Electronic Materials}, volume = {10}, journal = {Advanced Electronic Materials}, number = {2}, issn = {2199-160X}, doi = {10.1002/aelm.202300624}, abstract = {Hot electron transistors (HETs) represent an exciting frontier in semiconductor technology, holding the promise of high-speed and high-frequency electronics. With the exploration of two-dimensional materials such as graphene and new device architectures, HETs are poised to revolutionize the landscape of modern electronics. This study highlights a novel HET structure with a record output current density of 800 A/cm² and a high current gain α, fabricated using a scalable fabrication approach. The HET structure comprises two-dimensional hexagonal boron nitride (hBN) and graphene layers wet transferred to a germanium substrate. The combination of these materials results in exceptional performance, particularly in terms of the highly saturated output current density. The scalable fabrication scheme used to produce the HET opens up opportunities for large-scale manufacturing. This breakthrough in HET technology holds promise for advanced electronic applications, offering high current capabilities in a practical and manufacturable device.}, language = {en} } @misc{PechmannPerezWengeretal., author = {Pechmann, Stefan and P{\´e}rez, Eduardo and Wenger, Christian and Hagelauer, Amelie}, title = {A current mirror Based read circuit design with multi-level capability for resistive switching deviceb}, series = {2024 International Conference on Electronics, Information, and Communication (ICEIC)}, journal = {2024 International Conference on Electronics, Information, and Communication (ICEIC)}, publisher = {Institute of Electrical and Electronics Engineers (IEEE)}, isbn = {979-8-3503-7188-8}, issn = {2767-7699}, doi = {10.1109/ICEIC61013.2024.10457188}, pages = {4}, abstract = {This paper presents a read circuit design for resistive memory cells based on current mirrors. The circuit utilizes high-precision current mirrors and reference cells to determine the state of resistive memory using comparators. It offers a high degree in adaptability in terms of both resistance range and number of levels. Special emphasis was put on device protection to prevent accidental programming of the memory during read operations. The realized circuit can resolve eight states with a resolution of up to 1 k Ω, realizing a digitization of the analog memory information. Furthermore, the integration in a complete memory macro is shown. The circuit was realized in a 130 nm-process but can easily be adapted to other processes and resistive memory technologies.}, language = {en} } @misc{NikiruyPerezBaronietal., author = {Nikiruy, Kristina and P{\´e}rez, Eduardo and Baroni, Andrea and Dorai Swamy Reddy, Keerthi and Pechmann, Stefan and Wenger, Christian and Ziegler, Martin}, title = {Blooming and pruning: learning from mistakes with memristive synapses}, series = {Scientific Reports}, volume = {14}, journal = {Scientific Reports}, number = {1}, issn = {2045-2322}, doi = {10.1038/s41598-024-57660-4}, abstract = {AbstractBlooming and pruning is one of the most important developmental mechanisms of the biological brain in the first years of life, enabling it to adapt its network structure to the demands of the environment. The mechanism is thought to be fundamental for the development of cognitive skills. Inspired by this, Chialvo and Bak proposed in 1999 a learning scheme that learns from mistakes by eliminating from the initial surplus of synaptic connections those that lead to an undesirable outcome. Here, this idea is implemented in a neuromorphic circuit scheme using CMOS integrated HfO2-based memristive devices. The implemented two-layer neural network learns in a self-organized manner without positive reinforcement and exploits the inherent variability of the memristive devices. This approach provides hardware, local, and energy-efficient learning. A combined experimental and simulation-based parameter study is presented to find the relevant system and device parameters leading to a compact and robust memristive neuromorphic circuit that can handle association tasks.}, language = {en} } @misc{ErekathSeidlitzSchreineretal., author = {Erekath, Swathi and Seidlitz, Holger and Schreiner, Monika and Dreyer, Christian}, title = {Food for future: Exploring cutting-edge technology and practices in vertical farm}, series = {Sustainable Cities and Society}, volume = {106}, journal = {Sustainable Cities and Society}, issn = {2210-6707}, doi = {10.1016/j.scs.2024.105357}, abstract = {With the growing urbanized population, vertical farming becomes indispensable in eradicating hunger and ensuring food security for the future. Food security has become a major challenge for the future owing to the scarcity of land, rising global population, urbanization, and polluted soil and water resources. In this scenario, vertical farming as an innovative food production technology caters increased productivity with limited resources and improved carbon footprint. The review begins with a brief introduction to the concept of vertical farming, its opportunities and implications on the economy, environment, and society as a whole, following with an in-depth qualitative analysis of the cutting-edge innovations/technologies are presented in detail. Contrary to the numerous research focusing on mere analysis of economic viability and statistical analysis, the aim is to introduce real cutting-edge technologies that address the challenges of vertical farms such as lack of technical skills or energy requirements. The recent advances of vertical farms includes construction of outer vertical structure and growing shelves using light weight and transparent polymer composites, engineered and tunable LEDs lightings, 3-D printed and recyclable growing substrates, AI-integrated IoTs for environment control, harvesting materials for renewable energy storage etc. Such material innovations with inclusion of AI and robotics transform automated vertical farming into 'state of the art' agricultural technology. Production shelf fabricated using UV cured GBOV-glass fiber composite with 60\% transparency can overcome the material weight limitation, corrosion, light obstructions etc. associated with the conventional steel shelves. Replacing non-renewable fossil fuels using renewable energy harvested by carbon dots, fluorescent materials, and perovskite solar cells is recommended to minimize the high capital investments associated with energy as well as to reduce the environmental impact. Smart materials such as phase change materials and thermoresponsive windows control the amount of energy expended whereas smart substrate promotes resource management. Application of the newest technology AI in vertical farming facilitates precise control of environment, early pest detection, automation of farming processes, data-driven decision making and precision agriculture. In short, vertical farms utilizing modern innovations of science and technology caters enhanced productivity, improved quality, reduced cost, resource management and sustainability. Hence, automated and sustainable vertical farms promoting global food security and circularity have the potential to transform into burgeoning technology of future.}, language = {en} } @misc{RecupidoLamaSteffenetal., author = {Recupido, Federica and Lama, Giuseppe Cesare and Steffen, Sebastian and Dreyer, Christian and Seidlitz, Holger and Russo, Vincenzo and Lavorgna, Marino and De Luca Bossa, Ferdinando and Silvano, Selena and Boggioni, Laura and Verdolotti, Letizia}, title = {Efficient recycling pathway of bio-based composite polyurethane foams via sustainable diamine}, series = {Ecotoxicology and Environmental Safety}, volume = {269}, journal = {Ecotoxicology and Environmental Safety}, issn = {0147-6513}, doi = {10.1016/j.ecoenv.2023.115758}, abstract = {Aminolysis is widely recognized as a valuable chemical route for depolymerizing polymeric materials containing ester, amide, or urethane functional groups, including polyurethane foams. Bio-based polyurethane foams, pristine and reinforced with 40 wt\% of sustainable fillers, were depolymerized in the presence of bio-derived butane-1,4-diamine, BDA. A process comparison was made using fossil-derived ethane-1,2-diamine, EDA, by varying amine/polyurethane ratio (F/A, 1:1 and 1:0.6). The obtained depolymerized systems were analyzed by FTIR and NMR characterizations to understand the effect of both diamines on the degradation pathway. The use of bio-based BDA seemed to be more effective with respect to conventional EDA, owing to its stronger basicity (and thus higher nucleophilicity), corresponding to faster depolymerization rates. BDA-based depolymerized systems were then employed to prepare second-generation bio-based composite polyurethane foams by partial replacement of isocyanate components (20 wt\%). The morphological, mechanical, and thermal conductivity properties of the second-generation polyurethane foams were evaluated. The best performances (σ10 \%=71 ± 9 kPa, λ = 0.042 ± 0.015 W∙ m-1 ∙K-1) were attained by employing the lowest F/A ratio (1:0.6); this demonstrates their potential application in different sectors such as packaging or construction, fulfilling the paradigm of the circular economy.}, language = {en} } @inproceedings{WenVargasZhuetal., author = {Wen, Jianan and Vargas, Fabian Luis and Zhu, Fukun and Reiser, Daniel and Baroni, Andrea and Fritscher, Markus and P{\´e}rez, Eduardo and Reichenbach, Marc and Wenger, Christian and Krstic, Milos}, title = {Cycle-Accurate FPGA Emulation of RRAM Crossbar Array: Efficient Device and Variability Modeling with Energy Consumption Assessment}, series = {2024 IEEE 25th Latin American Test Symposium (LATS)}, booktitle = {2024 IEEE 25th Latin American Test Symposium (LATS)}, publisher = {IEEE}, doi = {10.1109/LATS62223.2024.10534601}, pages = {6}, abstract = {Emerging device technologies such as resistive RAM (RRAM) are increasingly recognized in enhancing system performance, particularly in applications demanding extensive vector-matrix multiplications (VMMs) with high parallelism. However, a significant limitation in current electronics design automation (EDA) tools is their lack of support for rapid prototyping, design space exploration, and the integration of inherent process-dependent device variability into system-level simulations, which is essential for assessing system reliability. To address this gap, we introduce a field-programmable gate array (FPGA) based emulation approach for RRAM crossbars featuring cycle-accurate emulations in real time without relying on complex device models. Our approach is based on pre-generated look-up tables (LUTs) to accurately represent the RRAM device behavior. To efficiently model the device variability at the system level, we propose using the multivariate kernel density estimation (KDE) method to augment the measured RRAM data. The proposed emulator allows precise latency determination for matrix mapping and computation operations. Meanwhile, by coupling with the NeuroSim framework, the corresponding energy consumption can be estimated. In addition to facilitating a range of in-depth system assessments, experimental results suggest a remarkable reduction of emulation time compared to the classic behavioral simulation.}, language = {en} } @misc{KehmWasilewskiMiahetal., author = {Kehm, Christian and Wasilewski, Eric and Miah, Kamal Uddin Mohammad and Ossenbrink, Ralf and Seidlitz, Holger}, title = {Effects of extended shielding gas coverage on component contour accuracy in Wire Arc Additive Manufacturing}, series = {4th Symposium on Materials and Additive Manufacturing, Additive 2024, 22. - 24. Mai 2024, Book of Abstracts}, journal = {4th Symposium on Materials and Additive Manufacturing, Additive 2024, 22. - 24. Mai 2024, Book of Abstracts}, publisher = {Deutsche Gesellschaft f{\"u}r Materialkunde (DGM) e.V.}, address = {Bremen, Berlin}, isbn = {978-3-88355-440-2}, pages = {29}, abstract = {Producing near-net-shape components with Wire Arc Additive Manufacturing (WAAM) is a challenging task. Compared to laser-based additive manufacturing technologies, WAAM is characterized by a lower contour accuracy with higher surface roughness and more uneven surface profiles. Therefore, the WAAM requires a high degree of post-processing (machining) which reduces economic efficiency and increases material consumption. Therefore, topics such as process optimization with regard to the component contour are increasingly in the focus of research. This study presents the application of an extended shielding gas coverage in the WAAM process of steel to improve part contour accuracy. A specially adapted shielding gas coverage was manufactured with laser powder bed fusion and following used to study the influence on the resulting component contour and properties in comparison to standard shielding gas nozzles. The investigations include the analysis of temperature profiles, shape deviations, hardness and porosity in the component. In addition, process parameters such as gas flow rate and nozzle geometry were varied in order to evaluate their influence on the accuracy of the component contour. The extended shielding gas coverage reduces the average deviation from the target contour significantly by a degree of 49,44\%. In addition, the maximum of the occurring deviation height could be decreased by 42,39\%. The results show an improvement in the dimensional accuracy of the contour and the surface quality, resulting in higher reproducibility and less post-processing effort.}, language = {en} } @misc{DoraiSwamyReddyPerezBaronietal., author = {Dorai Swamy Reddy, Keerthi and P{\´e}rez, Eduardo and Baroni, Andrea and Mahadevaiah, Mamathamba Kalishettyhalli and Marschmeyer, Steffen and Fraschke, Mirko and Lisker, Marco and Wenger, Christian and Mai, Andreas}, title = {Optimization of technology processes for enhanced CMOS-integrated 1T-1R RRAM device performance}, series = {The European Physical Journal B}, volume = {97}, journal = {The European Physical Journal B}, publisher = {Springer Science and Business Media LLC}, issn = {1434-6028}, doi = {10.1140/epjb/s10051-024-00821-1}, pages = {9}, abstract = {Implementing artificial synapses that emulate the synaptic behavior observed in the brain is one of the most critical requirements for neuromorphic computing. Resistive random-access memories (RRAM) have been proposed as a candidate for artificial synaptic devices. For this applicability, RRAM device performance depends on the technology used to fabricate the metal-insulator-metal (MIM) stack and the technology chosen for the selector device. To analyze these dependencies, the integrated RRAM devices in a 4k-bit array are studied on a 200 mm wafer scale in this work. The RRAM devices are integrated into two different CMOS transistor technologies of IHP, namely 250 nm and 130 nm and the devices are compared in terms of their pristine state current. The devices in 130 nm technology have shown lower number of high pristine state current devices per die in comparison to the 250 nm technology. For the 130 nm technology, the forming voltage is reduced due to the decrease of HfO2 dielectric thickness from 8 nm to 5 nm. Additionally, 5\% Al-doped 4 nm HfO2 dielectric displayed a similar reduction in forming voltage and a lower variation in the values. Finally, the multi-level switching between the dielectric layers in 250 nm and 130 nm technologies are compared, where 130 nm showed a more significant number of conductance levels of seven compared to only four levels observed in 250 nm technology.}, language = {en} } @misc{SchmittBorckBehmetal., author = {Schmitt, Randolf and Borck, Christian and Behm, Martin and B{\"o}hnke, Jacob}, title = {Approach of an asset combination based on RAMI4.0 for the digital transformation and operation of a Digital Twin}, series = {Procedia CIRP}, volume = {130}, journal = {Procedia CIRP}, publisher = {Elsevier BV}, issn = {2212-8271}, doi = {10.1016/j.procir.2024.10.155}, pages = {724 -- 729}, language = {en} } @article{BartschBorckBehmetal., author = {Bartsch, Devis and Borck, Christian and Behm, Martin and B{\"o}hnke, Jacob}, title = {Development of a Multi-layered Quality Assurance Framework for Manual Assembly Processes in the Aviation Industry}, series = {Procedia CIRP}, volume = {130}, journal = {Procedia CIRP}, publisher = {Elsevier BV}, issn = {2212-8271}, doi = {10.1016/j.procir.2024.10.232}, pages = {1227 -- 1233}, language = {en} } @misc{StaedterRaetze, author = {St{\"a}dter, Christian and Raetze, Sebastian}, title = {Effectiveness in esports : an integrative multilevel review}, series = {Esports Research Network Conference 2024}, journal = {Esports Research Network Conference 2024}, publisher = {Research Gate}, abstract = {Introduction: Esports have evolved from unorganized activities into hyper-competitive and professionalized settings. Esports share similarities with professional sports where individuals and teams strive for optimal performance. The purpose of our paper is to systematically review and integrate the fast-growing research on individual and team effectiveness in gaming and esports. To the best of our knowledge, we provide the first systematic review of research on gaming and esports effectiveness. Research Question: What are the individual, team, and organizational/environmental factors that are associated with effectiveness in gaming and esports? Methodology: We leveraged a systematic literature review approach and conducted a structured keyword search in Web of Science, Google Scholar, and EBSCO. The sample was completed using forward-backward tracking. The resulting sample consists of 180 articles after full-text screening. Results: Within our full paper we will leverage the input-mediator-outcome-input (IMOI) model to synthesize the existing findings on the multilevel factors that shape individual and team effectiveness in gaming and esports. In doing so, we will integrate previous findings from across the individual, team, and organizational/environmental levels into outcomes (e.g., win/loss ratio and prize money winnings), mediators (e.g., team cohesion and communication), and inputs (e.g., individual athlete skills, team compositional variables). Building on our integration, we 2 will discuss blind spots and contradicting findings within this model, and outline an agenda for future research. Implications: Scholars can leverage our work by systematically targeting the identified blind spots and contradicting findings that exist within the literature. Practitioners will find value in focusing on factors shown to positively impact effectiveness within this setting.}, language = {en} } @misc{StaedterBennettPoulusetal., author = {St{\"a}dter, Christian and Bennett, Kyle and Poulus, Dylan and Leis, Oliver and Sharpe, Benjamin T. and Nicholson, Mitchell}, title = {Reporting esports samples : a scoping review}, series = {Esports Research Network Conference 2024}, journal = {Esports Research Network Conference 2024}, publisher = {Research Gate}, abstract = {Introduction: The growth of gaming and esports has spurred increased academic interest and research across various disciplines. However, the relative novelty of this field means that best practices are not yet established, leading to inconsistent and inadequate sample information. This paper systematically reviews the existing literature, examining how researchers report esports samples, and addresses gaps identified in previous reviews, such as Mendoza et al. (2023). Research Questions: What descriptive information is provided when reporting esports samples? What categories have been adopted to date when addressing such samples? Methodology: We leveraged a scoping review approach following PRISMA-ScR guidelines. We conduct a structured keyword search in databases (Web of Science, EBSCOhost, Google Scholar, and Science Direct) across multiple disciplines in Mai 2024, using the PICO model. In our review, only peer-reviewed, primary, empirical, English studies will be included. 2 Results: The search provided an initial sample consisting of 8,536 articles before screening. Within our full paper we will, we will report main study outcomes, characteristics of all relevant literature, and highlight emerging trends. Discussion: We will discuss key outcomes such as quality and quantity of information as well as terms used by researchers based on the literature. Furthermore, strengths and limitations, as well as current practices and lack thereof will be highlighted. Lastly, we will suggest guidance for future research regarding esports sampling.}, language = {en} } @misc{RaetzeHuellmannStaedter, author = {Raetze, Sebastian and H{\"u}llmann, Joschka and St{\"a}dter, Christian}, title = {Not all adversity is equal: Analyzing the impact of different trigger types on team coordination and performance based on digital trace data from professional esports}, series = {Interdisciplinary Network for Group Research (INGRoup) 2024}, journal = {Interdisciplinary Network for Group Research (INGRoup) 2024}, publisher = {Research Gate}, pages = {23}, abstract = {Teams are prevalent across various industries, undertaking a significant portion of contemporary work (Benson-Armer \& Hsieh, 1997). Good functioning of teams is paramount, given its pivotal role in enhancing productivity and fostering corporate success (LePine, 2005). As such, organizational teamwork stands as a widely explored subject, attracting attention from both the popular press and academia (Duhigg, 2016). In the academic realm, the primary aim is to understand the drivers of team effectiveness, with most studies employing frameworks such as the input-process-outcome model (McGrath, 1984) or the advanced input-mediator-outcome model (Ilgen et al., 2005), which cluster variables related to effective teamwork into process categories. For instance, team research has long focused on compositional factors as inputs, revealing the significant influence that factors such as personality, knowledge, and skills of team members exert on team processes and performance (e.g., Mathieu et al., 2008; 2019). While valuable, much of the existing research on organizational teams has adopted a static approach, focusing on teams performing routine tasks at specific moments in time (e.g., Cronin et al., 2011; Klonek et al., 2019). However, this approach fails to capture the dynamic nature of most teams operating today, which are fluid entities that evolve and adapt over time (e.g., Ramos-Villagrasa et al., 2018). Consequently, the challenges a team faces at one point may not remain stable throughout its entire lifecycle. Events or disruptions can profoundly influence a team's functioning and performance (Liu et al., 2023). Likewise, a team's past experiences can shape its ability to navigate present disruptions. This is even more pertinent in today's era of 28 discontinuity and perpetual change where most teams frequently encounter challenges that demand immediate action and have the potential to disrupt critical team processes and states (e.g., Alliger et al., 2015; Driskell et al., 2018). Due to these developments, there has been an exponential increase in research on teamwork in challenging contexts, encompassing studies on various fronts such as extreme teams (Schmutz et al., 2023), team resilience (Raetze et al., 2021), and team adaptation (e.g., Maynard et al., 2015). However, even within these domains, there has been limited emphasis on trigger events and temporal dynamics. For instance, while many definitions of team resilience acknowledge adversity as a trigger and imply temporal effects like recovery, they often operationalize team resilience as a collective state at a particular moment in time (Raetze et al., 2022). Although the team adaptation literature demonstrates a stronger focus on how trigger types influence team processes and outcomes (Rico et al., 2019; 2020), empirical evidence remains sparse (Christian et al., 2017). Furthermore, the existing empirical work investigating how teams adapt to adversity has predominantly centered on disruptions occurring before or between different task execution rounds (e.g., Argote et al., 1995; Kane et al., 2005). Consequently, we argue that research elucidating the role of adversity in effective teamwork remains at a nascent stage (Edmondson \& McManus, 2007). In response, in our study, we aim to provide an in-depth exploration of how various types of adverse events influence team routines and performance, with a specific focus on the role of temporal variables. To achieve this, we utilize high-resolution data obtained from the innovative setting of professional esports. Professional esports represents a dynamic and demanding environment where athletes or teams compete for substantial prize money. Our analysis concentrates on demo files from Counter-Strike:Global Offensive (CS:GO), a team-based first-person shooter game, which comprise 41,782 unique team performance episodes. From these 29 demos, we extract digital trace data, capturing events and behaviors 128 times per second. Employing methodologies rooted in Business Process Management (BPM) and Process Mining (van der Aalst, 2016), we will analyze this rich process data. Our analytical framework draws on established management theories such as EST (Morgeson et al., 2015), theories on team dynamics (e.g., Arrow \& McGrath, 1993; O'Leary et al., 2011), and insights from research on team resilience and adaptation (e.g., Rico et al., 2019; 2020; Stoverink et al., 2020). Study Context and Methodological Approach We searched for a context that offers high-resolution data (Klonek et al., 2019) on adverse events and process dynamics in real teams and found it in the domain of professional esports. Esports in general have evolved from recreational/unorganized activities into hyper-competitive/ professionalized settings (Pedraza-Ramirez, 2020). Professional athletes play full-time, earn a salary, and compete in tournaments and leagues with millions of dollars in prize money (Chan et al., 2022). In particular, we focus on the first-person shooter CS:GO, which is one of the most popular esports titles. Professional tournaments/leagues in this domain have structures and rules similar to traditional sports. In a game of CS:GO, two teams of five compete against each other. Each game consists of multiple rounds. Both teams move across a 3D map during a round (see Figure 2-1). The attacking team must plant and detonate a bomb, whereas the defending team tries to stop this from happening. At the beginning of each round, all players start with 100 health points, and each player can acquire weapons and utilities of varying strength and cost by spending money to fight against the opponents. Money transitions across rounds, with each new round giving money to both teams. Weapon and utilities transition only across rounds if a player survives. Damage can be inflicted on players via weapons or utilities. When a player reaches 0 health points, the player dies and is revived at the start of the next round. The team that first accumulates 16 winning rounds wins the game. Each round can be considered a team 30 performance episode (Marks et al., 2001). Due to the aforementioned nature of modern esports, CS:GO teams at the highest levels can be compared to professional sports teams, which have a rich tradition in work teams research (Quigley et al., 2022), but also to critical action teams (Ishak \& Ballard, 2012). Yet, esports offers much richer and more fine-grained data than professional sports, which offers scholars the opportunity to analyze team process dynamics based on unobtrusive measures. For instance, during major CS:GO tournaments players and teams are video- and audio-recorded as are comments of several experts. Moreover, statistics and tournament demos are published on community websites. Our study focuses on demo files from professional CS:GO tournaments in 2021 and 2022. Each demo constitutes a digital trace data file of one game and grants access to the entirety of a team's behavioral data during this game (e.g., events, player's position, movement, and action). Digital trace data allow for including fine-grained contextual information in the description of processes (Pentland et al., 2020) and has gained momentum in management and team research recently (e.g., Hansson et al., 2022; Wax et al., 2017). In particular, we acquired the esports trajectories and actions (ESTA) dataset comprising 1,558 replays with 41,782 rounds played accounting for 8.6 million game events (Xenopoulos \& Silva, 2022). The events are accompanied by more than 110 attributes, describing the game state at each 1/128 fraction of a second (as professional games are played at 128 frames per second with each frame representing the entire game state at this particular point in time). Current State and Next Steps Using high-resolution data to understand team dynamics is challenging. As such, team scholars have seldomly applied such approaches and there is also limited methodological guidance (Klonek et al., 2019). We know even less about how to leverage digital traces as a particularly complex type of high-resolution data (Mahringer, 2021; Pentland et al., 2020). 31 Accordingly, such research requires a more exploratory and iterative approach (Uitdewilligen \& Waller, 2018). For instance, for assigning our data to meaningful team concepts, we have to go back and forth between theory and data to test which concepts can be operationalized and which cannot (Klonek et al., 2019). Likewise, the extremely high resolution of our data (i.e., 128 measurement points per second) creates very high complexity which calls for simplification. At this stage of our project, we have created an initial set of operationalizations for events, team routines, and team performance within single team performance episodes (see Table 2-1). For instance, we operationalize adverse trigger events through in-game events such as damage, kill, or bomb planted against the focal team. These critical events significantly reduce the focal team's chance of winning a respective round (Xenopoulos et al., 2020). We operationalize team routines as the joint trajectory of team players' movements in the x- and y-dimensions throughout the round. For this, we reduced the 3D game state to a 2D game state, only considering variation in the horizontal and vertical axes (Gust et al., 2023). We thus ignored the 3D viewpoint of the players (i.e., where they are looking in-game) and only considered their positions (i.e., where they are standing or moving in-game). The team resources and team situations, which determine the choices of team routines, are operationalized via the game factors of equipment (i.e., the value of the team's in-game equipment such as weapons, grenades, and defusal kits) and the remaining total health of all players. These factors are also significantly related to the round outcomes (Xenopoulos et al., 2020; 2022). Finally, the round outcomes (i.e., round win and total damage inflicted on the opponent's team) operationalize the team performance for that respective round. Likewise, we follow an analytical approach to determine the observed routines of a focal team based on the "x,y" trajectories of its players. Figure 2-2 illustrates the "x,y" trajectories as measures of team routines. Using hierarchical clustering and manual labeling, we define types of team routines that are semantically viable (Hu et al., 2023; Studer \& Ritschard, 2016). 32 Subsequently, in further analysis, the observed routines are assigned to one of the defined routine types via maximizing trajectory similarity (minimizing distance). We use routine types and repertoires as predictors for team performance. Over the next weeks, we will finalize our analytical model and run our analyses. We are currently discussing/testing the operationalization of additional adversity-trigger characteristics (e.g., event time, event cluster/chains), types of impacts on team routines (e.g., collapse of routines, improvisation, sticking to a routine, switching to another routine), and alternative outcome measures (e.g., resilient performance) as well as options to analyze interrelations across single performance episodes (i.e., adding a developmental perspective; Klonek et al., 2019). During the conference, we will present our initial findings. Expected Findings and Conclusions Overall, we are very confident that our work will offer valuable insights into how accounting for adversity-trigger characteristics may shed new light on the consequences of adversity exposure on team processes and performance as well as adequate adversity management processes. Our fine-grained data will also allow us to take several temporal characteristics into account. This knowledge is strongly needed to support teams operating in today's complex environments.}, language = {en} } @misc{JiaPechmannMarkusetal., author = {Jia, Ruolan and Pechmann, Stefan and Markus, Fritscher and Wenger, Christian and Zhang, Lei and Hagelauer, Amelie}, title = {Soft-Error Analysis of RRAM 1T1R Compute-In-Memory Core for Artificial Neural Networks}, series = {2024 39th Conference on Design of Circuits and Integrated Systems (DCIS)}, journal = {2024 39th Conference on Design of Circuits and Integrated Systems (DCIS)}, publisher = {IEEE}, doi = {10.1109/DCIS62603.2024.10769203}, pages = {1 -- 5}, abstract = {This work analyses SEU-induced soft-errors in analog compute-in-memory cores using resistive random-access memory (RRAM) for artificial neural networks, where their bitcells utilize one-transistor-one-RRAM (1T1R) structure. This is modeled by combining the Stanford-PKU RRAM Model and the model of the radiation-induced photocurrent in access transistors. As results, this work derives the maximal RRAM crossbar size without occurring any logic flip and indicates the requirements for RRAM technology to achieve a SEU-resilient 1T1R compute-in memory cores.}, language = {en} } @misc{PerezBoschQuesadaMistroniJiaetal., author = {Perez-Bosch Quesada, Emilio and Mistroni, Alberto and Jia, Ruolan and Dorai Swamy Reddy, Keerthi and Reichmann, Felix and Castan, Helena and Due{\~n}as, Salvador and Wenger, Christian and Perez, Eduardo}, title = {Forming and resistive switching of HfO₂-based RRAM devices at cryogenic temperature}, series = {IEEE Electron Device Letters}, volume = {45}, journal = {IEEE Electron Device Letters}, number = {12}, publisher = {Institute of Electrical and Electronics Engineers (IEEE)}, issn = {0741-3106}, doi = {10.1109/LED.2024.3485873}, pages = {2391 -- 2394}, abstract = {Reliable data storage technologies able to operate at cryogenic temperatures are critical to implement scalable quantum computers and develop deep-space exploration systems, among other applications. Their scarce availability is pushing towards the development of emerging memories that can perform such storage in a non-volatile fashion. Resistive Random-Access Memories (RRAM) have demonstrated their switching capabilities down to 4K. However, their operability at lower temperatures still remain as a challenge. In this work, we demonstrate for the first time the forming and resistive switching capabilities of CMOS-compatible RRAM devices at 1.4K. The HfO2-based devices are deployed following an array of 1-transistor-1-resistor (1T1R) cells. Their switching performance at 1.4K was also tested in the multilevel-cell (MLC) approach, storing up to 4 resistance levels per cell.}, language = {en} } @misc{WeisshauptSuergersBloosetal., author = {Weißhaupt, David and S{\"u}rgers, Christoph and Bloos, Dominik and Funk, Hannes Simon and Oehme, Michael and Fischer, Gerda and Schubert, Markus Andreas and Wenger, Christian and van Slageren, Joris and Fischer, Inga Anita and Schulze, J{\"o}rg}, title = {Lateral Mn5Ge3 spin-valve in contact with a high-mobility Ge two-dimensional hole gas}, series = {Semiconductor Science and Technology}, volume = {39}, journal = {Semiconductor Science and Technology}, number = {12}, publisher = {IOP Publishing}, issn = {0268-1242}, doi = {10.1088/1361-6641/ad8d06}, pages = {1 -- 10}, abstract = {Abstract Ge two-dimensional hole gases (2DHG) in strained modulation-doped quantum-wells represent a promising material platform for future spintronic applications due to their excellent spin transport properties and the theoretical possibility of efficient spin manipulation. Due to the continuous development of epitaxial growth recipes extreme high hole mobilities and low effective masses can be achieved, promising an efficient spin transport. Furthermore, the Ge 2DHG can be integrated in the well-established industrial complementary metal-oxide-semiconductor (CMOS) devices technology. However, efficient electrical spin injection into a Ge 2DHG—an essential prerequisite for the realization of spintronic devices—has not yet been demonstrated. In this work, we report the fabrication and low-temperature magnetoresistance (MR) measurements of a laterally structured Mn5Ge3/Ge 2DHG/ Mn5Ge3 device. The ferromagnetic Mn5Ge3 contacts are grown directly into the Ge quantum well by means of an interdiffusion process with a spacing of approximately 130 nm, forming a direct electrical contact between the ferromagnetic metal and the Ge 2DHG. Here, we report for the first time a clear MR signal for temperatures below 13 K possibly arising from successful spin injection into the high mobility Ge 2DHG. The results represent a step forward toward the realization of CMOS compatible spintronic devices based on a 2DHG.}, language = {en} } @incollection{EisenmannSeibertWinkler, author = {Eisenmann, Christine and Seibert, Dennis and Winkler, Christian}, title = {Introduction}, series = {Acceptance and diffusion of connected and automated driving in Japan and Germany}, booktitle = {Acceptance and diffusion of connected and automated driving in Japan and Germany}, publisher = {Springer Nature Switzerland}, address = {Cham}, isbn = {9783031598753}, doi = {10.1007/978-3-031-59876-0_1}, pages = {1 -- 5}, abstract = {AbstractThis opening chapter provides an initial overview of the various topics covered in the book, which explores CAD's implications, focusing on societal acceptance and technology diffusion. Key areas include the impact of existing mobility systems on CAD adoption, policy frameworks, ride-hailing market potential, and public perception in Germany and Japan. Through modeling and empirical studies, the research examines CAD's effects on transport systems, car ownership, and travel demand. This Japanese-German collaboration highlights CAD's importance for both countries, given their advanced automotive industries and demographic challenges, offering insights for future research and policy development.}, language = {en} } @misc{WitkabelAbendroth, author = {Witkabel, Philipp and Abendroth, Christian}, title = {A systematic literature review of microbial anammox consortia in UASB/ EGSB-reactors}, series = {Chemosphere}, volume = {367}, journal = {Chemosphere}, publisher = {Elsevier BV}, issn = {0045-6535}, doi = {10.1016/j.chemosphere.2024.143630}, pages = {17}, abstract = {Anaerobic ammonium oxidation (anammox) poses an emerging research field as it can outstand previous processes of biological wastewater treatment in terms of efficiency and costs. Anammox bacteria have the ability to metabolise NH4+ and NO2- to produce N2 under anaerobic conditions. Despite numerous studies, there is a lack of research on the co-occurrence and interrelationship of the predominant microbes that inhabit anammox-related processes. This systematic literature review follows the PSALSAR approach to assess metagenomic data on anammox bacteria and functional microbes in upstream reactors. Essential information on the physiology, metabolic pathways and inhibitory effects of anammox bacteria are reviewed and functional bacteria such as ammonia-oxidising bacteria (AOB), nitrite-oxidising bacteria (NOB), ammonia-oxidising Archaea (AOA) and denitrifying bacteria are identified. Candidatus Kuenenia and Candidatus Brocadia were the most frequently sequenced genera in the observed literature. Pseudomonadota, Chloroflexota and Bacteroidota were prevalent regardless of crucial operational parameters and configurations that affect the microbial community. Interrelationship analysis revealed a positive association between the versatility of a phylum's metabolism and its presence in the observed wastewater treatment literature. Several groups, such as Calditrichota, Myxococcota and Deinococcota are highly underrepresented, a finding that should be investigated in more detail. No evidence was found to suggest that high anammox ratios are correlated with high nitrogen removal efficiencies, as some studies found high efficiency despite low anammox abundance (<1\%).}, language = {en} } @misc{OttoPucholRoyoOrtegaLegarretaetal., author = {Otto, Pascal and Puchol-Royo, Roser and Ortega-Legarreta, Asier and Tanner, Kristie and Tideman, Jeroen and De Vries, Sjoerd-Jan and Pascual, Javier and Porcar, Manuel and Latorre-P{\´e}rez, Adriel and Abendroth, Christian}, title = {Multivariate comparison of taxonomic, chemical and operational data from 80 different full-scale anaerobic digester-related systems}, series = {Biotechnology for Biofuels and Bioproducts}, volume = {17}, journal = {Biotechnology for Biofuels and Bioproducts}, doi = {10.1186/s13068-024-02525-1}, pages = {1 -- 17}, abstract = {Background: The holistic characterization of different microbiomes in anaerobic digestion (AD) systems can contribute to a better understanding of these systems and provide starting points for bioengineering. The present study investigates the microbiome of 80 European full-scale AD systems. Operational, chemical and taxonomic data were thoroughly collected, analysed and correlated to identify the main drivers of AD processes. Results: The present study describes chemical and operational parameters for a broad spectrum of different AD systems. With this data, Spearman correlation and differential abundance analyses were applied to narrow down the role of the individual microorganisms detected. The authors succeeded in further limiting the number of microorganisms in the core microbiome for a broad range of AD systems. Based on 16S rRNA gene amplicon sequencing, MBA03, Proteiniphilum, a member of the family Dethiobacteraceae, the genus Caldicoprobacter and the methanogen Methanosarcina were the most prevalent and abundant organisms identified in all digesters analysed. High ratios for Methanoculleus are often described for agricultural co-digesters. Therefore, it is remarkable that Methanosarcina was surprisingly high in several digesters reaching ratios up to 47.2\%. The various statistical analyses revealed that the microorganisms grouped according to different patterns. A purely taxonomic correlation enabled a distinction between an acetoclastic cluster and a hydrogenotrophic one. However, in the multivariate analysis with chemical parameters, the main clusters corresponded to hydrolytic and acidogenic microorganisms, with SAOB bacteria being particularly important in the second group. Including operational parameters resulted in digester-type specific grouping of microbes. Those with separate acidification stood out among the many reactor types due to their unexpected behaviour. Despite maximizing the organic loading rate in the hydrolytic pretreatments, these stages turned into extremely robust methane production units. Conclusions: From 80 different AD systems, one of the most holistic data sets is provided. A very distinct formation of microbial clusters was discovered, depending on whether taxonomic, chemical or operational parameters were combined. The microorganisms in the individual clusters were strongly dependent on the respective reference parameters.}, language = {en} } @misc{CapistaLukoseMajnoonetal., author = {Capista, Daniele and Lukose, Rasuole and Majnoon, Farnaz and Lisker, Marco and Wenger, Christian and Lukosius, Mindaugas}, title = {Optimization of the metal deposition process for the accurate estimation of Low Metal-Graphene Contact-Resistance}, series = {47th MIPRO ICT and Electronics Convention (MIPRO), 20-24 May 2024, Opatija, Croatia}, journal = {47th MIPRO ICT and Electronics Convention (MIPRO), 20-24 May 2024, Opatija, Croatia}, isbn = {979-8-3503-8250-1}, issn = {2623-8764}, doi = {10.1109/MIPRO60963.2024.10569895}, pages = {5}, language = {en} } @misc{MaldonadoCantudoSwamyReddyetal., author = {Maldonado, David and Cantudo, Antonio and Swamy Reddy, Keerthi Dorai and Pechmann, Stefan and Uhlmann, Max and Wenger, Christian and Roldan, Juan Bautista and P{\´e}rez, Eduardo}, title = {Influence of stop and gate voltage on resistive switching of 1T1R HfO2-based memristors, a modeling and variability analysis}, series = {Materials Science in Semiconductor Processing}, volume = {182}, journal = {Materials Science in Semiconductor Processing}, issn = {1873-4081}, doi = {10.1016/j.mssp.2024.108726}, pages = {9}, language = {en} } @misc{KostoTschammerMoralesetal., author = {Kosto, Yuliia and Tschammer, Rudi and Morales, Carlos and Henkel, Karsten and Flege, Jan Ingo and Ratzke, Markus and Fischer, Inga Anita and Costina, Ioan and Alvarado Chavarin, Carlos and Wenger, Christian}, title = {Rational design and development of room temperature hydrogen sensors compatible with CMOS technology: a necessary step for the coming renewable hydrogen economy}, series = {Proceedings of iCampus Conference Cottbus 2024}, journal = {Proceedings of iCampus Conference Cottbus 2024}, publisher = {AMA Service GmbH}, address = {Wunstorf}, isbn = {978-3-910600-00-3}, doi = {10.5162/iCCC2024/P21}, pages = {182 -- 185}, abstract = {The transition towards a new, renewable energy system based on green energy vectors, such as hydrogen, requires not only direct energy conversion and storage systems, but also the development of auxiliary components, such as highly sensitive hydrogen gas sensors integrated into mass devices that operate at ambient conditions. Despite the recent advances in nanostructured metal oxide thin films in terms of simple fabrication processes and compatibility with integrated circuits, high sensitivity, and short response/recovery times usually require the use of expensive noble metals or elevated tem-peratures (>250 ºC), which results in high power consumption and poor long-term stability. This article presents the first steps of the work on developing a novel resistive hydrogen gas sensor based on ultrathin cerium oxide films, compatible with complementary metal oxide semiconductor technology and capable of operating at room temperature. Here, we show a multidisciplinary bottom-up approach combining different work areas for the sensor development, such as sensor architecture, sensing mechanism and deposition strategy of the active layer, electrical contact design depending on the desired electrical output, and fast testing under controlled environments.}, language = {en} } @misc{OttoAbendroth, author = {Otto, Pascal and Abendroth, Christian}, title = {Neue Bakterienordnung entdeckt}, series = {Biogas Journal}, volume = {2024}, journal = {Biogas Journal}, number = {2}, issn = {1619-8913}, pages = {96 -- 99}, abstract = {Wissenschaftler*innen des europ{\"a}ischen Forschungsprojektes Micro4Biogas haben eine neue taxonomische Ordnung von Bakterien entdeckt und klassifiziert, die auf die Zersetzung von organischem Material spezialisiert sind und der Schl{\"u}ssel zu einer optimierten Biogasproduktion sein k{\"o}nnten. Die von ihnen als Darwinibacteriales bezeichnete Ordnung ist eine der am h{\"a}ufigsten vorkommenden Bakterien-Ordnungen in Biogasanlagen, wurde aber bisher noch nie wissenschaftlich klassifiziert.}, language = {de} } @misc{KieneSchottMartinCreuzburgetal., author = {Kiene, Marvin and Schott, Matthias and Martin-Creuzburg, Dominik and Laforsch, Christian}, title = {Food quantity and quality modulates inducible defenses in a common predator-prey system}, series = {Limnology and Oceanography}, volume = {69}, journal = {Limnology and Oceanography}, number = {7}, issn = {1939-5590}, doi = {10.1002/lno.12595}, pages = {1546}, language = {en} } @misc{VinuesaGarciaPerezetal., author = {Vinuesa, Guillermo and Garc{\´i}a, H{\´e}ctor and P{\´e}rez, Eduardo and Wenger, Christian and {\´I}{\~n}iguez de la Torre, Ignacio and Gonz{\´a}lez, Tom{\´a}s and Due{\~n}as, Salvador and Cast{\´a}n, Helena}, title = {On the asymmetry of Resistive Switching Transitions}, series = {Electronics}, volume = {13}, journal = {Electronics}, number = {13}, publisher = {MDPI}, issn = {2079-9292}, doi = {10.3390/electronics13132639}, pages = {11}, abstract = {In this study, the resistive switching phenomena in TiN/Ti/HfO2/Ti metal-insulator-metal stacks is investigated, mainly focusing on the analysis of set and reset transitions. The electrical measurements in a wide temperature range reveal that the switching transitions require less voltage (and thus, less energy) as temperature rises, with the reset process being much more temperature sensitive. The main conduction mechanism in both resistance states is Space-charge-limited Conduction, but the high conductivity state also shows Schottky emission, explaining its temperature dependence. Moreover, the temporal evolution of these transitions reveals clear differences between them, as their current transient response is completely different. While the set is sudden, the reset process development is clearly non-linear, closely resembling a sigmoid function. This asymmetry between switching processes is of extreme importance in the manipulation and control of the multi-level characteristics and has clear implications in the possible applications of resistive switching devices in neuromorphic computing.}, language = {en} } @misc{StrobelAlvaradoChavarinKnautetal., author = {Strobel, Carsten and Alvarado Chavarin, Carlos and Knaut, Martin and Albert, Matthias and Heinzig, Andr{\´e} and Gummadi, Likhith and Wenger, Christian and Mikolajick, Thomas}, title = {p-Type Schottky contacts for graphene adjustable-Barrier phototransistors}, series = {Nanomaterials}, volume = {14}, journal = {Nanomaterials}, number = {13}, editor = {Giannazzo, Filippo and Agnello, Simonpietro and Seravalli, Luca and Bondino, Federica}, publisher = {MDPI}, issn = {2079-4991}, doi = {10.3390/nano14131140}, abstract = {The graphene adjustable-barriers phototransistor is an attractive novel device for potential high speed and high responsivity dual-band photodetection. In this device, graphene is embedded between the semiconductors silicon and germanium. Both n-type and p-type Schottky contacts between graphene and the semiconductors are required for this device. While n-type Schottky contacts are widely investigated, reports about p-type Schottky contacts between graphene and the two involved semiconductors are scarce. In this study, we demonstrate a p-type Schottky contact between graphene and p-germanium. A clear rectification with on-off ratios of close to 10 3 (±5 V) and a distinct photoresponse at telecommunication wavelengths in the infrared are achieved. Further, p-type silicon is transferred to or deposited on graphene, and we also observe rectification and photoresponse in the visible range for some of these p-type Schottky junctions. These results are an important step toward the realization of functional graphene adjustable-barrier phototransistors.}, language = {en} } @misc{MoralesPlateMarthetal., author = {Morales, Carlos and Plate, Paul and Marth, Ludwig and Naumann, Franziska and Kot, Małgorzata and Janowitz, Christoph and Kus, Peter and Z{\"o}llner, Marvin Hartwig and Wenger, Christian and Henkel, Karsten and Flege, Jan Ingo}, title = {Bottom-up design of a supercycle recipe for atomic layer deposition of tunable Indium Gallium Zinc Oxide thin films}, series = {ACS Applied Electronic Materials}, volume = {6}, journal = {ACS Applied Electronic Materials}, number = {8}, publisher = {American Chemical Society (ACS)}, issn = {2637-6113}, doi = {10.1021/acsaelm.4c00730}, pages = {5694 -- 5704}, abstract = {We present a successful bottom-up approach to design a generic plasma-enhanced atomic layer deposition (PEALD) supercycle recipe to grow high-quality indium gallium zinc oxide (IGZO) thin films with tunable composition at a relatively low temperature of 150 °C. In situ real-time ellipsometric characterization in combination with ex situ complementary techniques has been used to optimize the deposition process and quality of the films by identifying and solving growth challenges such as degree of oxidation, nucleation delays, or elemental composition. The developed supercycle approach enables facile control of the target composition by adapting the subcycle ratios within the supercycle process. Compared to other low-temperature deposition techniques resulting in amorphous films, our PEALD-IGZO process at 150 °C results in nearly amorphous, nanocrystalline films. The preparation of IGZO films at low temperature by a supercycle PEALD approach allows controlling the thickness, composition, and electrical properties while preventing thermally induced segregation.}, language = {en} } @misc{VidalVerduTorrentIglesiasetal., author = {Vidal-Verd{\´u}, {\`A}ngela and Torrent, Daniel and Iglesias, Alba and Latorre-P{\´e}rez, Adriel and Abendroth, Christian and Corb{\´i}n-Agust{\´i}, Paola and Peret{\´o}, Juli and Porcar, Manuel}, title = {The highly differentiated gut of Pachnoda marginata hosts sequential microbiomes: microbial ecology and potential applications}, series = {npj Biofilms and Microbiomes}, volume = {10}, journal = {npj Biofilms and Microbiomes}, number = {1}, publisher = {Springer Science and Business Media LLC}, issn = {2055-5008}, doi = {10.1038/s41522-024-00531-7}, pages = {14}, abstract = {Insect gut microbiomes play a crucial role in the insect development and are shaped, among other factors, by the specialized insect diet habits as well as the morphological structure of the gut. Rose chafers (Pachnoda spp.; Coleoptera: Scarabaeidae) have a highly differentiated gut characterized by a pronounced hindgut dilation which resembles a miniaturized rumen. Specifically, the species Pachnoda marginata has not been previously studied in detail in terms of microbial ecology. Here, we show a fine scale study of the highly compartmentalized gut of P. marginata by using amplicon and metagenomic sequencing to shed light on the bacterial, archaeal and fungal communities thriving in each section of the gut. We found a microbial gradient along the gut from aerobic (foregut) to strictly anaerobic communities (hindgut). In addition, we have characterized interesting biological activities and metabolic pathways of gut microbial communities related to cellulose degradation, methane production and sulfate reduction. Taken together, our results reveal the highly diverse microbial community and the potential of P. marginata gut as a source of industrially relevant microbial diversity.}, language = {en} } @misc{BarthWernerOttoetal., author = {Barth, Maximilian and Werner, Magdalena and Otto, Pascal and Richwien, Benjamin and Bahramsari, Samira and Krause, Maximilian and Schwan, Benjamin and Abendroth, Christian}, title = {Microwave-assisted organic acids and green hydrogen production during mixed culture fermentation}, series = {Biotechnology for Biofuels and Bioproducts}, volume = {17}, journal = {Biotechnology for Biofuels and Bioproducts}, number = {1}, publisher = {Springer Science and Business Media LLC}, issn = {2731-3654}, doi = {10.1186/s13068-024-02573-7}, pages = {18}, abstract = {Background: The integration of anaerobic digestion into bio-based industries can create synergies that help render anaerobic digestion self-sustaining. Two-stage digesters with separate acidification stages allow for the production of green hydrogen and short-chain fatty acids, which are promising industrial products. Heat shocks can be used to foster the production of these products, the practical applicability of this treatment is often not addressed sufficiently, and the presented work therefore aims to close this gap. Methods: Batch experiments were conducted in 5 L double-walled tank reactors incubated at 37 °C. Short microwave heat shocks of 25 min duration and exposure times of 5-10 min at 80 °C were performed and compared to oven heat shocks. Pairwise experimental group differences for gas production and chemical parameters were determined using ANOVA and post-hoc tests. High-throughput 16S rRNA gene amplicon sequencing was performed to analyse taxonomic profiles. Results: After heat-shocking the entire seed sludge, the highest hydrogen productivity was observed at a substrate load of 50 g/l with 1.09 mol H2/mol hexose. With 1.01 mol H2/mol hexose, microwave-assisted treatment was not significantly different from oven-based treatments. This study emphasised the better repeatability of heat shocks with microwave-assisted experiments, revealing low variation coefficients averaging 29\%. The pre-treatment with microwaves results in a high predictability and a stronger microbial community shift to Clostridia compared to the treatment with the oven. The pre-treatment of heat shocks supported the formation of butyric acid up to 10.8 g/l on average, with a peak of 24.01 g/l at a butyric/acetic acid ratio of 2.0. Conclusion: The results support the suitability of using heat shock for the entire seed sludge rather than just a small inoculum, making the process more relevant for industrial applications. The performed microwave-based treatment has proven to be a promising alternative to oven-based treatments, which ultimately may facilitate their implementation into industrial systems. This approach becomes economically sustainable with high-temperature heat pumps with a coefficient of performance (COP) of 4.3.}, language = {en} } @misc{KupkeDropcoGoetzetal., author = {Kupke, Laura S. and Dropco, Ivor and G{\"o}tz, Markus and Kupke, Paul and Jung, Friedrich and Stroszczynski, Christian and Jung, Ernst Michael}, title = {Contrast-enhanced intraoperative ultrasound shows excellent performance in improving intraoperative decision-making}, series = {Life}, volume = {14}, journal = {Life}, number = {9}, editor = {Miraglia, Roberto}, publisher = {MDPI}, issn = {2075-1729}, doi = {10.3390/life14091199}, pages = {10}, abstract = {Background: The aim of this study was to evaluate the performance and the impact of contrast-enhanced intraoperative ultrasound (CE-IOUS) on intraoperative decision-making, as there is still no standardized protocol for its use. Therefore, we retrospectively analyzed multiple CE-IOUS performed in hepato-pancreatic-biliary surgery with respect to pre- and postoperative imaging and histopathological findings. Methods: Data of 50 patients who underwent hepato-pancreatic-biliary surgery between 03/2022 and 03/2024 were retrospectively collected. CE-IOUS was performed with a linear 6-9 MHz multifrequency probe connected to a high-resolution device. The ultrasound contrast agent used was a stabilized aqueous suspension of sulphur hexafluoride microbubbles. Results: In total, all 50 lesions indicated for surgery were correctly identified. In 30 cases, CE-IOUS was used to localize the primary lesion and to define the resection margins. In the remaining 20 cases, CE-IOUS identified an additional lesion. Fifteen of these findings were identified as malignant. In eight of these cases, the additional malignant lesion was subsequently resected. In the remaining seven cases, CE-IOUS again revealed an inoperable situation. In summary, CE-IOUS diagnostics resulted in a high correct classification rate of 95.7\%, with positive and negative predictive values of 95.2\% and 100.0\%, respectively. Conclusions: CE-IOUS shows excellent performance in describing intraoperative findings in hepato-pancreatic-biliary surgery, leading to a substantial impact on intraoperative decision-making.}, language = {en} } @misc{HayatRatzkeAlvaradoChavarinetal., author = {Hayat, Ahsan and Ratzke, Markus and Alvarado Chavarin, Carlos and Z{\"o}llner, Marvin Hartwig and Corley-Wiciak, Agnieszka Anna and Schubert, Markus Andreas and Wenger, Christian and Fischer, Inga Anita}, title = {Structural and morphological properties of CeO2 films deposited by radio frequency magnetron sputtering for back-end-of-line integration}, series = {Thin Solid Films}, volume = {807}, journal = {Thin Solid Films}, issn = {0040-6090}, doi = {10.1016/j.tsf.2024.140547}, pages = {3}, language = {en} } @misc{PalacioBunnRahnetal., author = {Palacio, Juan Camilo Rivera and Bunn, Christian and Rahn, Eric and Little-Savage, Daisy and Schmidt, Paul G{\"u}nter and Ryo, Masahiro}, title = {Geographic-scale coffee cherry counting with smartphones and deep learning}, series = {Plant Phenomics}, volume = {6}, journal = {Plant Phenomics}, publisher = {American Association for the Advancement of Science (AAAS)}, issn = {2643-6515}, doi = {10.34133/plantphenomics.0165}, pages = {11}, abstract = {Deep learning and computer vision, using remote sensing and drones, are 2 promising nondestructive methods for plant monitoring and phenotyping. However, their applications are infeasible for many crop systems under tree canopies, such as coffee crops, making it challenging to perform plant monitoring and phenotyping at a large spatial scale at a low cost. This study aims to develop a geographic-scale monitoring method for coffee cherry counting, supported by an artificial intelligence (AI)-powered citizen science approach. The approach uses basic smartphones to take a few pictures of coffee trees; 2,968 trees were investigated with 8,904 pictures in Jun{\´i}n and Piura (Peru), Cauca, and Quind{\´i}o (Colombia) in 2022, with the help of nearly 1,000 smallholder coffee farmers. Then, we trained and validated YOLO (You Only Look Once) v8 for detecting cherries in the dataset in Peru. An average number of cherries per picture was multiplied by the number of branches to estimate the total number of cherries per tree. The model's performance in Peru showed an R2 of 0.59. When the model was tested in Colombia, where different varieties are grown in different biogeoclimatic conditions, the model showed an R2 of 0.71. The overall performance in both countries reached an R2 of 0.72. The results suggest that the method can be applied to much broader scales and is transferable to other varieties, countries, and regions. To our knowledge, this is the first AI-powered method for counting coffee cherries and has the potential for a geographic-scale, multiyear, photo-based phenotypic monitoring for coffee crops in low-income countries worldwide.}, language = {en} } @misc{BergerBellBartonetal., author = {Berger, Uta and Bell, Andrew and Barton, C. Michael and Chappin, Emile and Dreßler, Gunnar and Filatova, Tatiana and Fronville, Thibault and Lee, Allen and Loon, Emiel van and Lorscheid, Iris and Meyer, Matthias and M{\"u}ller, Birgit and Piou, Cyril and Radchuk, Viktoriia and Roxburgh, Nicholas and Sch{\"u}ler, Lennart and Troost, Christian and Wijermans, Nanda and Williams, Tim G. and Wimmler, Marie-Christin and Grimm, Volker}, title = {Towards reusable building blocks for agent-based modelling and theory development}, series = {Environmental Modelling \& Software}, volume = {175}, journal = {Environmental Modelling \& Software}, publisher = {Elsevier BV}, issn = {1364-8152}, doi = {10.1016/j.envsoft.2024.106003}, pages = {12}, language = {en} } @misc{EisenhauerFrankWeigeltetal., author = {Eisenhauer, Nico and Frank, Karin and Weigelt, Alexandra and Bartkowski, Bartosz and Beugnon, R{\´e}my and Liebal, Katja and Mahecha, Miguel and Quaas, Martin and Al-Halbouni, Djamil and Bastos, Ana and Bohn, Friedrich J. and Brito, Mariana Madruga de and Denzler, Joachim and Feilhauer, Hannes and Fischer, Rico and Fritsche, Immo and Guimaraes-Steinicke, Claudia and H{\"a}nsel, Martin and Haun, Daniel B. M. and Herrmann, Hartmut and Huth, Andreas and Kalesse-Los, Heike and Koetter, Michael and Kolleck, Nina and Krause, Melanie and Kretschmer, Marlene and Leit{\~a}o, Pedro J. and Masson, Torsten and Mora, Karin and M{\"u}ller, Birgit and Peng, Jian and P{\"o}hlker, Mira L. and Ratzke, Leonie and Reichstein, Markus and Richter, Solveig and R{\"u}ger, Nadja and S{\´a}nchez-Parra, Beatriz and Shadaydeh, Maha and Sippel, Sebastian and Tegen, Ina and Thr{\"a}n, Daniela and Umlauft, Josefine and Wendisch, Manfred and Wolf, Kevin and Wirth, Christian and Zacher, Hannes and Zaehle, S{\"o}nke and Quaas, Johannes}, title = {A belowground perspective on the nexus between biodiversity change, climate change, and human well-being}, series = {Journal of Sustainable Agriculture and Environment}, volume = {3}, journal = {Journal of Sustainable Agriculture and Environment}, number = {2}, publisher = {Wiley}, issn = {2767-035X}, doi = {10.1002/sae2.12108}, pages = {12}, abstract = {Soil is central to the complex interplay among biodiversity, climate, and society. This paper examines the interconnectedness of soil biodiversity, climate change, and societal impacts, emphasizing the urgent need for integrated solutions. Human-induced biodiversity loss and climate change intensify environmental degradation, threatening human well-being. Soils, rich in biodiversity and vital for ecosystem function regulation, are highly vulnerable to these pressures, affecting nutrient cycling, soil fertility, and resilience. Soil also crucially regulates climate, influencing energy, water cycles, and carbon storage. Yet, climate change poses significant challenges to soil health and carbon dynamics, amplifying global warming. Integrated approaches are essential, including sustainable land management, policy interventions, technological innovations, and societal engagement. Practices like agroforestry and organic farming improve soil health and mitigate climate impacts. Effective policies and governance are crucial for promoting sustainable practices and soil conservation. Recent technologies aid in monitoring soil biodiversity and implementing sustainable land management. Societal engagement, through education and collective action, is vital for environmental stewardship. By prioritizing interdisciplinary research and addressing key frontiers, scientists can advance understanding of the soil biodiversity-climate change-society nexus, informing strategies for environmental sustainability and social equity.}, language = {en} } @misc{CouedelFalconnierAdametal., author = {Cou{\"e}del, Antoine and Falconnier, Gatien N. and Adam, Myriam and Cardinael, R{\´e}mi and Boote, Kenneth and Justes, Eric and Smith, Ward N. and Whitbread, Anthony Michael and Affholder, Fran{\c{c}}ois and Balkovic, Juraj and Basso, Bruno and Bhatia, Arti and Chakrabarti, Bidisha and Chikowo, Regis and Christina, Mathias and Faye, Babacar and Ferchaud, Fabien and Folberth, Christian and Akinseye, Folorunso M. and Gaiser, Thomas and Galdos, Marcelo V. and Gayler, Sebastian and Gorooei, Aram and Grant, Brian and Guibert, Herv{\´e} and Hoogenboom, Gerrit and Kamali, Bahareh and Laub, Moritz and Maureira, Fidel and Mequanint, Fasil and Nendel, Claas and Porter, Cheryl H. and Ripoche, Dominique and Ruane, Alex C. and Rusinamhodzi, Leonard and Sharma, Shikha and Singh, Upendra and Six, Johan and Srivastava, Amit Kumar and Vanlauwe, Bernard and Versini, Antoine and Vianna, Murilo and Webber, Heidi and Weber, Tobias K. D. and Zhang, Congmu and Corbeels, Marc}, title = {Long-term soil organic carbon and crop yield feedbacks differ between 16 soil-crop models in sub-Saharan Africa}, series = {European Journal of Agronomy}, volume = {155}, journal = {European Journal of Agronomy}, publisher = {Elsevier BV}, issn = {1161-0301}, doi = {10.1016/j.eja.2024.127109}, pages = {16}, abstract = {Food insecurity in sub-Saharan Africa is partly due to low staple crop yields, resulting from poor soil fertility and low nutrient inputs. Integrated soil fertility management (ISFM), which includes the combined use of mineral and organic fertilizers, can contribute to increasing yields and sustaining soil organic carbon (SOC) in the long term. Soil-crop simulation models can help assess the performance and trade-offs of a range of crop management practices including ISFM, under current and future climate. Yet, uncertainty in model simulations can be high, resulting from poor model calibration and/or inadequate model structure. Multi-model simulations have been shown to be more robust than those with single models and help understand and reduce modelling uncertainty. In this study, we aim to perform the first multi-model comparison for long-term simulations of crop yield and SOC and their feedbacks in SSA. We evaluated the performance of 16 soil-crop models using data from four long-term maize experiments at sites in SSA with contrasting climates and soils. Each experiment had four treatments: i) no exogenous inputs, ii) addition of mineral nitrogen (N) fertilizer, iii) use of organic amendments, and iv) combined use of mineral and organic inputs. We assessed model performance in two steps: through blind calibration involving a minimum level of experimental data provided to the modeling teams, and subsequently through full calibration, which included a more extensive set of observational data. Model ensemble accuracy was greater with full calibration than blind calibration. Improvement in model accuracy was larger for maize yields (nRMSE 48 vs 18\%) than for topsoil SOC (nRMSE 22 vs 14\%). Model ensemble uncertainty (defined as the coefficient of variation across the 16 models) increased over the duration of the long-term experiments. Uncertainty of SOC simulations increased when organic amendments were used, whilst uncertainty of yield predictions was largest when no inputs were applied. Our study revealed large discrepancies among the models in simulating i) crop-to-soil feedbacks due to uncertainties in simulated carbon coming from roots, and ii) soil-to-crop feedbacks due to large uncertainties in simulated crop N supply from soil organic matter decomposition. These discrepancies were largest when organic amendments were applied. The results highlight the need for long-term experiments in which root and soil N dynamics are monitored. This will provide the corresponding data to improve and calibrate soil-crop models, which will lead to more robust and reliable simulations of SOC and crop productivity, and their interactions.}, language = {en} } @misc{FritscherSinghRizzietal., author = {Fritscher, Markus and Singh, Simranjeet and Rizzi, Tommaso and Baroni, Andrea and Reiser, Daniel and Mallah, Maen and Hartmann, David and Bende, Ankit and Kempen, Tim and Uhlmann, Max and Kahmen, Gerhard and Fey, Dietmar and Rana, Vikas and Menzel, Stephan and Reichenbach, Marc and Krstic, Milos and Merchant, Farhad and Wenger, Christian}, title = {A flexible and fast digital twin for RRAM systems applied for training resilient neural networks}, series = {Scientific Reports}, volume = {14}, journal = {Scientific Reports}, number = {1}, publisher = {Springer Science and Business Media LLC}, issn = {2045-2322}, doi = {10.1038/s41598-024-73439-z}, pages = {13}, abstract = {Resistive Random Access Memory (RRAM) has gained considerable momentum due to its non-volatility and energy efficiency. Material and device scientists have been proposing novel material stacks that can mimic the "ideal memristor" which can deliver performance, energy efficiency, reliability and accuracy. However, designing RRAM-based systems is challenging. Engineering a new material stack, designing a device, and experimenting takes significant time for material and device researchers. Furthermore, the acceptability of the device is ultimately decided at the system level. We see a gap here where there is a need for facilitating material and device researchers with a "push button" modeling framework that allows to evaluate the efficacy of the device at system level during early device design stages. Speed, accuracy, and adaptability are the fundamental requirements of this modelling framework. In this paper, we propose a digital twin (DT)-like modeling framework that automatically creates RRAM device models from device measurement data. Furthermore, the model incorporates the peripheral circuit to ensure accurate energy and performance evaluations. We demonstrate the DT generation and DT usage for multiple RRAM technologies and applications and illustrate the achieved performance of our GPU implementation. We conclude with the application of our modeling approach to measurement data from two distinct fabricated devices, validating its effectiveness in a neural network processing an Electrocardiogram (ECG) dataset and incorporating Fault Aware Training (FAT).}, language = {en} }