TY - JOUR A1 - Clavijo, Leonardo A1 - Zlatanovic, Slobodan A1 - Braun, Gerd A1 - Bongards, Michael A1 - Dieste, Andrés A1 - Barbe, Stéphan T1 - Eucalyptus Kraft Lignin as an Additive Strongly Enhances the Mechanical Resistance of Tree-Leaf Pellets JF - Processes N2 - Pelleted biomass has a low, uniform moisture content and can be handled and stored cheaply and safely. Pellets can be made of industrial waste, food waste, agricultural residues, energy crops, and virgin lumber. Despite their many desirable attributes, they cannot compete with fossil fuel sources because the process of densifying the biomass and the price of the raw materials make pellet production costly. Leaves collected from street sweeping are generally discarded in landfills, but they can potentially be valorized as a biofuel if they are pelleted. However, the lignin content in leaves is not high enough to ensure the physical stability of the pellets, so they break easily during storage and transportation. In this study, the use of eucalyptus kraft lignin as an additive in tree-leaf pellet production was studied. Results showed that when 2% lignin is added the abrasion resistance can be increased to an acceptable value. Pellets with added lignin fulfilled all requirements of European standards for certification except for ash content. However, as the raw material has no cost, this method can add value or contribute to financing continued sweeping and is an example of a circular economy scenario. KW - Kreislaufwirtschaft KW - Eucalyptus kraft lignin KW - Tree leaf KW - Pellet KW - Additive KW - Biofuel KW - Circular economy KW - Pellet KW - Blatt Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:832-epub4-15216 SN - 2227-9717 VL - 8 IS - 3 PB - MDPI ER - TY - JOUR A1 - Riedel, Carolin A1 - Förstner, Konrad U. A1 - Püning, Christoph A1 - Alter, Thomas A1 - Sharma, Cynthia M. A1 - Gölz, Greta T1 - Differences in the Transcriptomic Response of Campylobacter coli and Campylobacter lari to Heat Stress JF - Frontiers in Microbiology N2 - Campylobacter spp. are one of the most important food-borne pathogens, which are quite susceptible to environmental or technological stressors compared to other zoonotic bacteria. This might be due to the lack of many stress response mechanisms described in other bacteria. Nevertheless, Campylobacter is able to survive in the environment and food products. Although some aspects of the heat stress response in Campylobacter jejuni are already known, information about the stress response in other Campylobacter species are still scarce. In this study, the stress response of Campylobacter coli and Campylobacter lari to elevated temperatures (46°C) was investigated by survival assays and whole transcriptome analysis. None of the strains survived at 46°C for more than 8 h and approximately 20% of the genes of C. coli RM2228 and C. lari RM2100 were differentially expressed. The transcriptomic profiles showed enhanced gene expression of several chaperones like dnaK, groES, groEL, and clpB in both strains, indicating a general involvement in the heat stress response within the Campylobacter species. However, the pronounced differences in the expression pattern between C. coli and C. lari suggest that stress response mechanisms described for one Campylobacter species might be not necessarily transferable to other Campylobacter species. KW - Heat stress response KW - Transcriptome sequencing KW - RNA-seq Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:832-epub4-15136 SN - 1664-302X VL - 11 PB - Frontiers Media S.A. ER - TY - JOUR A1 - Nguyen, Minh D. A1 - Baez-Villanueva, Oscar M. A1 - Bui, Duong D. A1 - Nguyen, Phong T. A1 - Ribbe, Lars T1 - Harmonization of Landsat and Sentinel 2 for Crop Monitoring in Drought Prone Areas: Case Studies of Ninh Thuan (Vietnam) and Bekaa (Lebanon) JF - Remote Sensing N2 - Proper satellite-based crop monitoring applications at the farm-level often require near-daily imagery at medium to high spatial resolution. The combination of data from different ongoing satellite missions Sentinel 2 (ESA) and Landsat 7/8 (NASA) provides this unprecedented opportunity at a global scale; however, this is rarely implemented because these procedures are data demanding and computationally intensive. This study developed a robust stream processing for the harmonization of Landsat 7, Landsat 8 and Sentinel 2 in the Google Earth Engine cloud platform, connecting the benefit of coherent data structure, built-in functions and computational power in the Google Cloud. The harmonized surface reflectance images were generated for two agricultural schemes in Bekaa (Lebanon) and Ninh Thuan (Vietnam) during 2018–2019. We evaluated the performance of several pre-processing steps needed for the harmonization including the image co-registration, Bidirectional Reflectance Distribution Functions correction, topographic correction, and band adjustment. We found that the misregistration between Landsat 8 and Sentinel 2 images varied from 10 m in Ninh Thuan (Vietnam) to 32 m in Bekaa (Lebanon), and posed a great impact on the quality of the final harmonized data set if not treated. Analysis of a pair of overlapped L8-S2 images over the Bekaa region showed that, after the harmonization, all band-to-band spatial correlations were greatly improved. Finally, we demonstrated an application of the dense harmonized data set for crop mapping and monitoring. An harmonic (Fourier) analysis was applied to fit the detected unimodal, bimodal and trimodal shapes in the temporal NDVI patterns during one crop year in Ninh Thuan province. The derived phase and amplitude values of the crop cycles were combined with max-NDVI as an R-G-B false composite image. The final image was able to highlight croplands in bright colors (high phase and amplitude), while the non-crop areas were shown with grey/dark (low phase and amplitude). The harmonized data sets (with 30 m spatial resolution) along with the Google Earth Engine scripts used are provided for public use. KW - Satellit KW - Landsat KW - Sentinel 2 KW - Harmonization KW - Ccrop monitoring KW - Google Earth Engine KW - Ernte KW - Überwachung KW - Libanon KW - Vietnam Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:832-epub4-15081 SN - 2072-4292 VL - 12 IS - 2 PB - MDPI ER - TY - JOUR A1 - Weiner, Pascal A1 - Neef, Caterina A1 - Shibata, Yoshihisa A1 - Nakamura, Yoshihiko A1 - Asfour, Tamim T1 - An Embedded, Multi-Modal Sensor System for Scalable Robotic and Prosthetic Hand Fingers JF - Sensors N2 - Grasping and manipulation with anthropomorphic robotic and prosthetic hands presents a scientific challenge regarding mechanical design, sensor system, and control. Apart from the mechanical design of such hands, embedding sensors needed for closed-loop control of grasping tasks remains a hard problem due to limited space and required high level of integration of different components. In this paper we present a scalable design model of artificial fingers, which combines mechanical design and embedded electronics with a sophisticated multi-modal sensor system consisting of sensors for sensing normal and shear force, distance, acceleration, temperature, and joint angles. The design is fully parametric, allowing automated scaling of the fingers to arbitrary dimensions in the human hand spectrum. To this end, the electronic parts are composed of interchangeable modules that facilitate the echanical scaling of the fingers and are fully enclosed by the mechanical parts of the finger. The resulting design model allows deriving freely scalable and multimodally sensorised fingers for robotic and prosthetic hands. Four physical demonstrators are assembled and tested to evaluate the approach. KW - Handprothese KW - Sensorised fingers KW - Tactile sensors KW - Parametric model KW - Robotic fingers KW - Prosthetic fingers KW - Hand prostheses KW - Anthropomorphic robotic hands KW - Roboterhand KW - Taktiler Sensor Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:832-epub4-14715 SN - 1424-8220 VL - 20 IS - 1 PB - MDPI ER - TY - JOUR A1 - Sharma, Roshan A1 - Rimal, Bhagawat A1 - Baral, Himlal A1 - Nehren, Udo A1 - Paudyal, Kiran A1 - Sharma, Sunil A1 - Rijal, Sushila A1 - Ranpal, Surendra A1 - Acharya, Ram Prasad A1 - Alenazy, Amer A. A1 - Kandel, Prashid T1 - Impact of Land Cover Change on Ecosystem Services in a Tropical Forested Landscape JF - Resources N2 - Ecosystems provide a wide range of goods, services or ecosystem services (ES) to society. Estimating the impact of land use and land cover (LULC) changes on ES values (ESV) is an important tool to support decision making. This study used remote sensing and GIS tools to analyze LULC change and transitions from 2001 to 2016 and assess its impact on ESV in a tropical forested landscape in the southern plains of Nepal. The total ESV of the landscape for the year 2016 is estimated at USD 1264 million year−1. As forests are the dominant land cover class and have high ES value per hectare, they have the highest contribution in total ESV. However, as a result of LULC change (loss of forests, water bodies, and agricultural land), the total ESV of the landscape has declined by USD 11 million year−1. Major reductions come from the loss in values of climate regulation, water supply, provision of raw materials and food production. To halt the ongoing loss of ES and maintain the supply and balance of different ES in the landscape, it is important to properly monitor, manage and utilize ecosystems. We believe this study will inform policymakers, environmental managers, and the general public on the ongoing changes and contribute to developing effective land use policy in the region. KW - Tropischer Wald KW - Land use and land cover change KW - Deforestation and forest degradation KW - Tropical forests KW - Ecosystem service valuation KW - Remote sensing KW - Entwaldung KW - Landnutzung KW - Ökosystem Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:832-epub4-14648 SN - 2079-9276 VL - 8 IS - 1 PB - MDPI ER - TY - JOUR A1 - Hartl, Christoph T1 - Review on Advances in Metal Micro-Tube Forming JF - Metals N2 - Metallic tubular micro-components play an important role in a broad range of products, from industrial microsystem technology, such as medical engineering, electronics and optoelectronics, to sensor technology or microfluidics. The demand for such components is increasing, and forming processes can present a number of advantages for industrial manufacturing. These include, for example, a high productivity, enhanced shaping possibilities, applicability of a wide spectrum of materials and the possibility to produce parts with a high stiffness and strength. However, certain difficulties arise as a result of scaling down conventional tube forming processes to the microscale. These include not only the influence of the known size effects on material and friction behavior, but also constraints in the feasible miniaturization of forming tools. Extensive research work has been conducted over the past few years on micro-tube forming techniques, which deal with the development of novel and optimized processes, to counteract these restrictions. This paper reviews the relevant advances in micro-tube fabrication and shaping. A particular focus is enhancement in forming possibilities, accuracy and obtained component characteristics, presented in the reviewed research work. Furthermore, achievements in severe plastic deformation for micro-tube generation and in micro-tube testing methods are discussed. KW - Micro-tubes KW - Micro-tube drawing KW - Micro-hydroforming KW - Laser assisted KW - Severe plastic deformation KW - Micro-tube testing KW - Mikrosystemtechnik KW - Rohr KW - Formgebung KW - Herstellung KW - Plastische Deformation Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:832-epub4-14635 SN - 2075-4701 VL - 9 IS - 5 PB - MDPI ER - TY - JOUR A1 - Limbu, Bibeg Hang A1 - Jarodzka, Halszka A1 - Klemke, Roland A1 - Specht, Marcus T1 - Can You Ink While You Blink? Assessing Mental Effort in a Sensor-Based Calligraphy Trainer JF - Sensors N2 - Sensors can monitor physical attributes and record multimodal data in order to provide feedback. The application calligraphy trainer, exploits these affordances in the context of handwriting learning. It records the expert’s handwriting performance to compute an expert model. The application then uses the expert model to provide guidance and feedback to the learners. However, new learners can be overwhelmed by the feedback as handwriting learning is a tedious task. This paper presents the pilot study done with the calligraphy trainer to evaluate the mental effort induced by various types of feedback provided by the application. Ten participants, five in the control group and five in the treatment group, who were Ph.D. students in the technology-enhanced learning domain, took part in the study. The participants used the application to learn three characters from the Devanagari script. The results show higher mental effort in the treatment group when all types of feedback are provided simultaneously. The mental efforts for individual feedback were similar to the control group. In conclusion, the feedback provided by the calligraphy trainer does not impose high mental effort and, therefore, the design considerations of the calligraphy trainer can be insightful for multimodal feedback designers. KW - Handschrift KW - Handwriting KW - Multimodal data KW - Expertise KW - Sensors KW - Training KW - Expertise KW - Sensor Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:832-epub4-14627 SN - 1424-8220 VL - 19 IS - 14 PB - MDPI ER - TY - JOUR A1 - Sachs, Julia A1 - Döhl, Katja A1 - Weber, Anja A1 - Bonus, Michele A1 - Ehlers, Ferdinand A1 - Fleischer, Edmond A1 - Klinger, Anette A1 - Gohlke, Holger A1 - Pietruszka, Jörg A1 - Schmitt, Lutz A1 - Teusch, Nicole T1 - Novel 3,4-Dihydroisocoumarins Inhibit Human P-gp and BCRP in Multidrug Resistant Tumors and Demonstrate Substrate Inhibition of Yeast Pdr5 JF - Frontiers in Pharmacology N2 - Multidrug resistance (MDR) in tumors and pathogens remains a major problem in the efficacious treatment of patients by reduction of therapy options and subsequent treatment failure. Various mechanisms are described to be involved in the development of MDR with overexpression of ATP-binding cassette (ABC) transporters reflecting the most extensively studied. These membrane transporters translocate a wide variety of substrates utilizing energy from ATP hydrolysis leading to decreased intracellular drug accumulation and impaired drug efficacy. One treatment strategy might be inhibition of transporter-mediated efflux by small molecules. Isocoumarins and 3,4-dihydroisocoumarins are a large group of natural products derived from various sources with great structural and functional variety, but have so far not been in the focus as potential MDR reversing agents. Thus, three natural products and nine novel 3,4-dihydroisocoumarins were designed and analyzed regarding cytotoxicity induction and inhibition of human ABC transporters P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1) and breast cancer resistance protein (BCRP) in a variety of human cancer cell lines as well as the yeast ABC transporter Pdr5 in Saccharomyces cerevisiae. Dual inhibitors of P-gp and BCRP and inhibitors of Pdr5 were identified, and distinct structure-activity relationships for transporter inhibition were revealed. The strongest inhibitor of P-gp and BCRP, which inhibited the transporters up to 80 to 90% compared to the respective positive controls, demonstrated the ability to reverse chemotherapy resistance in resistant cancer cell lines up to 5.6-fold. In the case of Pdr5, inhibitors were identified that prevented substrate transport and/or ATPase activity with IC50 values in the low micromolar range. However, cell toxicity was not observed. Molecular docking of the test compounds to P-gp revealed that differences in inhibition capacity were based on different binding affinities to the transporter. Thus, these small molecules provide novel lead structures for further optimization. KW - Multidrug-Resistenz KW - Multidrug resistance KW - Cancer chemotherapy KW - 4-dihydroisocoumarin KW - P-glycoprotein KW - Breast cancer resistance protein KW - Pdr5 KW - Chemotherapie KW - P-Glykoprotein KW - Brustkrebs Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:832-epub4-14593 SN - 1663-9812 VL - 10 PB - Frontiers Media S.A. ER - TY - JOUR A1 - Abubakar Jumare, Ismail A1 - Bhandari, Ramchandra A1 - Zerga, Abdellatif T1 - Environmental Life Cycle Assessment of Grid-Integrated Hybrid Renewable Energy Systems in Northern Nigeria JF - Sustainability N2 - Life cycle assessment is a crucial tool in evaluating systems performances for sustainability and decision-making. This paper provided environmental impact of integrating renewable energy systems to the utility-grid based on a baseline optimized energy production data from “HOMER” for renewable systems modelling of a site in northern Nigeria. The ultimate goal was to ascertain the best hybrid option(s) in sustaining the environment. Different assumptions and scenarios were modelled and simulated using Ganzleitlichen Bilanz (GaBi). Uncertainty analysis was ensured to the impact data based on pedigree-matrix and Excel-program, as well as overall policy relevance. The results of the impact categories revealed first scenario (i.e., conventional path-based) with the highest impacts on global warming potential (GWP), acidification potential (AP), human toxicity potential (HTP), and abiotic depletion potential (ADP fossils). The lowest impacts arise in the renewable-based scenarios for all the considered categories except the Ozone-layer depletion potential Category where the highest contribution falls in the third scenario (i.e., photovoltaic (PV)/biomass-biogas system) although all values being infinitesimal. In quantitative terms, the reduction in the GWP from the highest being the first scenario to the lowest being the fourth scenario (i.e., wind/biomass-biogas system) was 96.5%. Hence, with the outstanding contributions of the hybrid renewable systems, adopting them especially the lowest impact scenarios with expansions is relevant for environmental sustainability. KW - Hybrides System KW - Hybrid renewable energy system KW - Grid-integration KW - Life cycle assessment KW - Environmental KW - Uncertainty analyses KW - Policy relevance KW - Erneuerbare Energien KW - Umweltbilanz KW - Nigeria (Nord) Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:832-epub4-14568 SN - 2071-1050 VL - 11 IS - 21 ER - TY - JOUR A1 - Vosswinkel, Martin A1 - Lohner, Andreas A1 - Platte, Volkmar A1 - Hirche, Tobias T1 - Design, Production, and Verification of a Switched-Reluctance Wheel Hub Drive Train for Battery Electric Vehicles JF - World Electric Vehicle Journal N2 - This contribution deals with the topic of the consistent further development of a wheel hub motor for battery electric vehicles (BEV) based on the principle of an outer rotor switched reluctance machine (SRM). The research work presented in this paper was founded by the ERDF.NRW program, Investment for Growth and Employment and the European Regional Development Fund. The R&D project was named Switched - Reluctance fo(u)r wheel (SR4Wheel). Based on the experience made by first prototype Evolution 0 (EVO 0), developed in the Laboratory for Automation Engineering, Power Electronics and Electrical Drives of the Cologne University of Applied Sciences (CUAS), the test results of EVO 1, as well as the redesign, EVO 2 is presented in this paper. The prototype EVO 0, a first proof of concept leads to several optimizations and lessons learned for the predecessor model EVO 1. The overall target of developing such a gearless outer rotor wheel hub motor is the full integration of the complete machine including its power electronics into the given space between the original friction brake and the rim. Furthermore, due to the additional integration of the power electronics, great opportunities in terms of new vehicle design as well as retrofitting capabilities of already existing vehicle platforms can be achieved. Thereby, further drive train assembly space like the engine compartment is no longer necessary. The SRM does not require magnets for torque production which leads to independence from the changeable commodity prices on the rare earth element markets. This paper presents the developing process, testing, and verification of the innovative drive train concept starting with the final CAD of EVO 1. During the testing and verification process a machine characteristic mapping is performed on a drive train test bench and subsequently the results of a finite element analysis (FEA) are plausibility checked by the test bench results. The process continues with energy conversion test scenarios of the project demonstrator vehicle on a roller test bench focused on noise vibrationharshness (NVH) behavior and efficiency. As a conclusion, the gained knowledge by evaluating two EVO 1 prototypes on the rear axle of the test vehicle, and the design for the front axle drive train EVO 2 will be presented. As a major task on the front axle, the limited space due to the large disc brake can be identified and solved. KW - Elektrofahrzeug KW - Wheel hub motor KW - Switched reluctance machine KW - BEV (battery electric vehicle) KW - Electric drive KW - EV (electric vehicle) KW - Finite element calculation KW - Powertrain KW - Reluktanzmaschine KW - Radnabenmotor KW - Elektroantrieb KW - Triebstrang Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:832-epub4-14555 SN - 2032-6653 VL - 10 IS - 4 PB - MDPI ER -