@incollection{HoffschmidtAlexopoulosGoettscheetal.2012, author = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and G{\"o}ttsche, Joachim and Sauerborn, Markus}, title = {High concentration solar collectors}, series = {Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications}, volume = {3}, booktitle = {Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-0-08-087873-7}, doi = {10.1016/B978-0-08-087872-0.00306-1}, pages = {165 -- 209}, year = {2012}, abstract = {Solar thermal concentrated power is an emerging technology that provides clean electricity for the growing energy market. To the solar thermal concentrated power plant systems belong the parabolic trough, the Fresnel collector, the solar dish, and the central receiver system. For high-concentration solar collector systems, optical and thermal analysis is essential. There exist a number of measurement techniques and systems for the optical and thermal characterization of the efficiency of solar thermal concentrated systems. For each system, structure, components, and specific characteristics types are described. The chapter presents additionally an outline for the calculation of system performance and operation and maintenance topics. One main focus is set to the models of components and their construction details as well as different types on the market. In the later part of this chapter, different criteria for the choice of technology are analyzed in detail.}, language = {en} } @inproceedings{Hoffschmidt2008, author = {Hoffschmidt, Bernhard}, title = {Solar tower power plants}, series = {DME Seminar Desalination and Renewable Energies : June 19 and 20 2008, Solar Institut J{\"u}lich / Deutsche Meerwasserentsalzung e.V.}, booktitle = {DME Seminar Desalination and Renewable Energies : June 19 and 20 2008, Solar Institut J{\"u}lich / Deutsche Meerwasserentsalzung e.V.}, publisher = {DME}, address = {Duisbrug}, isbn = {978-3-86861-017-8}, pages = {219 Bl. in getr. Z{\"a}hlung : zahlr. Ill. und graph. Darst., Kt.}, year = {2008}, language = {en} } @inproceedings{HoffmannNierenGaebetal.2019, author = {Hoffmann, Katharina and Nieren, Monika and G{\"a}b, Martina and Kasper, Anna and Elbers, Gereon}, title = {The potential of near infrared spectroscopy (NIRS) for the environmental biomonitoring of plants}, series = {International conference on Life Sciences and Technology}, volume = {276}, booktitle = {International conference on Life Sciences and Technology}, number = {012009}, issn = {1755-1315}, doi = {10.1088/1755-1315/276/1/012009}, pages = {1 -- 3}, year = {2019}, abstract = {In the current environmental condition, the increase in pollution of the air, water, and soil indirectly will induce plants stress and decrease vegetation growth rate. These issues pay more attention to be solved by scientists worldwide. The higher level of chemical pollutants also induced the gradual changes in plants metabolism and decreased enzymatic activity. Importantly, environmental biomonitoring may play a pivotal contribution to prevent biodiversity degradation and plants stress due to pollutant exposure. Several previous studies have been done to monitor the effect of environmental changes on plants growth. Among that, Near Infrared spectroscopy (NIRS) offers an alternative way to observe the significant alteration of plant physiology caused by environmental damage related to pollution. Impairment of photosynthesis, nutrient and oxidative imbalances, and mutagenesis.}, language = {en} } @article{HoffmannUhlCeblinetal.2022, author = {Hoffmann, Andreas and Uhl, Matthias and Ceblin, Maximilian and Rohrbach, Felix and Bansmann, Joachim and Mallah, Marcel and Heuermann, Holger and Jacob, Timo and Kuehne, Alexander J.C.}, title = {Atmospheric pressure plasma-jet treatment of PAN-nonwovens—carbonization of nanofiber electrodes}, series = {C - Journal of Carbon Research}, volume = {8}, journal = {C - Journal of Carbon Research}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {2311-5629}, doi = {10.3390/c8030033}, pages = {8 Seiten}, year = {2022}, abstract = {Carbon nanofibers are produced from dielectric polymer precursors such as polyacrylonitrile (PAN). Carbonized nanofiber nonwovens show high surface area and good electrical conductivity, rendering these fiber materials interesting for application as electrodes in batteries, fuel cells, and supercapacitors. However, thermal processing is slow and costly, which is why new processing techniques have been explored for carbon fiber tows. Alternatives for the conversion of PAN-precursors into carbon fiber nonwovens are scarce. Here, we utilize an atmospheric pressure plasma jet to conduct carbonization of stabilized PAN nanofiber nonwovens. We explore the influence of various processing parameters on the conductivity and degree of carbonization of the converted nanofiber material. The precursor fibers are converted by plasma-jet treatment to carbon fiber nonwovens within seconds, by which they develop a rough surface making subsequent surface activation processes obsolete. The resulting carbon nanofiber nonwovens are applied as supercapacitor electrodes and examined by cyclic voltammetry and impedance spectroscopy. Nonwovens that are carbonized within 60 s show capacitances of up to 5 F g⁻¹.}, language = {en} } @article{HoffmannRohrbachUhletal.2022, author = {Hoffmann, Andreas and Rohrbach, Felix and Uhl, Matthias and Ceblin, Maximilian and Bauer, Thomas and Mallah, Marcel and Jacob, Timo and Heuermann, Holger and Kuehne, Alexander J. C.}, title = {Atmospheric pressure plasma-jet treatment of polyacrylonitrile-nonwovens—Stabilization and roll-to-roll processing}, series = {Journal of Applied Polymer Science}, volume = {139}, journal = {Journal of Applied Polymer Science}, number = {37}, publisher = {Wiley}, issn = {0021-8995 (Print)}, doi = {10.1002/app.52887}, pages = {1 -- 9}, year = {2022}, abstract = {Carbon nanofiber nonwovens represent a powerful class of materials with prospective application in filtration technology or as electrodes with high surface area in batteries, fuel cells, and supercapacitors. While new precursor-to-carbon conversion processes have been explored to overcome productivity restrictions for carbon fiber tows, alternatives for the two-step thermal conversion of polyacrylonitrile precursors into carbon fiber nonwovens are absent. In this work, we develop a continuous roll-to-roll stabilization process using an atmospheric pressure microwave plasma jet. We explore the influence of various plasma-jet parameters on the morphology of the nonwoven and compare the stabilized nonwoven to thermally stabilized samples using scanning electron microscopy, differential scanning calorimetry, and infrared spectroscopy. We show that stabilization with a non-equilibrium plasma-jet can be twice as productive as the conventional thermal stabilization in a convection furnace, while producing electrodes of comparable electrochemical performance.}, language = {en} } @inproceedings{HoevelerJanser2016, author = {Hoeveler, Bastian and Janser, Frank}, title = {The aerodynamically optimized design of a fan-in-wing duct}, series = {Applied Aerodynamics Research Conference 2016, Bristol, GB, Jul 19-21, 2016}, booktitle = {Applied Aerodynamics Research Conference 2016, Bristol, GB, Jul 19-21, 2016}, isbn = {1-85768-371-4}, pages = {1 -- 10}, year = {2016}, language = {en} } @article{HoevelerBauknechtWolfetal.2020, author = {Hoeveler, B. and Bauknecht, Andr{\´e} and Wolf, C. Christian and Janser, Frank}, title = {Wind-Tunnel Study of a Wing-Embedded Lifting Fan Remaining Open in Cruise Flight}, series = {Journal of Aircraft}, volume = {57}, journal = {Journal of Aircraft}, number = {4}, publisher = {AIAA}, address = {Reston, Va.}, issn = {1533-3868}, doi = {10.2514/1.C035422}, year = {2020}, abstract = {It is investigated whether a nonrotating lifting fan remaining uncovered during cruise flight, as opposed to being covered by a shutter system, can be realized with limited additional drag and loss of lift during cruise flight. A wind-tunnel study of a wing-embedded lifting fan has been conducted at the Side Wind Test Facility G{\"o}ttingen of DLR, German Aerospace Center in G{\"o}ttingen using force, pressure, and stereoscopic particle image velocimetry techniques. The study showed that a step on the lower side of the wing in front of the lifting fan duct increases the lift-to-drag ratio of the whole model by up to 25\% for all positive angles of attack. Different sizes and inclinations of the step had limited influence on the surface pressure distribution. The data indicate that these parameters can be optimized to maximize the lift-to-drag ratio. A doubling of the curvature radius of the lifting fan duct inlet lip on the upper side of the wing affected the lift-to-drag ratio by less than 1\%. The lifting fan duct inlet curvature can therefore be optimized to maximize the vertical fan thrust of the rotating lifting fan during hovering without affecting the cruise flight performance with a nonrotating fan.}, language = {en} } @article{Hoepner2004, author = {Hoepner, Gert}, title = {Info-Web-Generation}, series = {Dm-compact : academic news for marketeers / Deutscher Direktmarketing Verband e. V.. 2 (2004), H. 3-4}, journal = {Dm-compact : academic news for marketeers / Deutscher Direktmarketing Verband e. V.. 2 (2004), H. 3-4}, isbn = {1573-3181}, pages = {14 -- 20}, year = {2004}, language = {en} } @article{HoehrPaulssenBenardetal.2014, author = {Hoehr, Cornelia and Paulßen, Elisabeth and Benard, Francois and Lee, Chris Jaeil and Hou, Xinchi and Badesso, Brian and Ferguson, Simon and Miao, Qing and Yang, Hua and Buckley, Ken and Hanemaayer, Victoire and Zeisler, Stefan and Ruth, Thomas and Celler, Anna and Schaffer, Paul}, title = {⁴⁴ᶢSc production using a water target on a 13 MeV cyclotron}, series = {Nuclear medicine and biology}, volume = {41}, journal = {Nuclear medicine and biology}, number = {5}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-9614}, doi = {10.1016/j.nucmedbio.2013.12.016}, pages = {401 -- 406}, year = {2014}, abstract = {Access to promising radiometals as isotopes for novel molecular imaging agents requires that they are routinely available and inexpensive to obtain. Proximity to a cyclotron center outfitted with solid target hardware, or to an isotope generator for the metal of interest is necessary, both of which can introduce significant hurdles in development of less common isotopes. Herein, we describe the production of ⁴⁴Sc (t₁⸝₂ = 3.97 h, Eavg,β⁺ = 1.47 MeV, branching ratio = 94.27\%) in a solution target and an automated loading system which allows a quick turn-around between different radiometallic isotopes and therefore greatly improves their availability for tracer development. Experimental yields are compared to theoretical calculations.}, language = {en} } @inproceedings{HoegenDonckerRuetters2020, author = {Hoegen, Anne von and Doncker, Rik W. De and R{\"u}tters, Ren{\´e}}, title = {Teaching Digital Control of Operational Amplifier Processes with a LabVIEW Interface and Embedded Hardware}, series = {2020 23rd International Conference on Electrical Machines and Systems (ICEMS)}, booktitle = {2020 23rd International Conference on Electrical Machines and Systems (ICEMS)}, publisher = {IEEE}, address = {New York, NY}, doi = {10.23919/ICEMS50442.2020.9290928}, pages = {1117 -- 1122}, year = {2020}, abstract = {Control engineering theory is hard to grasp for undergraduates during the first semesters, as it deals with the dynamical behavior of systems also in combination with control strategies on an abstract level. Therefore, operational amplifier (OpAmp) processes are reasonable and very effective systems to connect mathematical description with actual system's behavior. In this paper, we present an experiment for a laboratory session in which an embedded system, driven by a LabVIEW human machine interface (HMI) via USB, controls the analog circuits.With this setup we want to show the possibility of firstly, analyzing a first order process and secondly, designing a P-and PI-controller. Thereby, the theory of control engineering is always applied to the empirical results in order to break down the abstract level for the students.}, language = {en} } @inproceedings{HoegenDonckerBragardetal.2021, author = {Hoegen, Anne von and Doncker, Rik W. De and Bragard, Michael and Hoegen, Svenja von}, title = {Problem-based learning in automation engineering: performing a remote laboratory aession aerving various educational attainments}, series = {2021 IEEE Global Engineering Education Conference (EDUCON)}, booktitle = {2021 IEEE Global Engineering Education Conference (EDUCON)}, publisher = {IEEE}, address = {New York, NY}, doi = {10.1109/EDUCON46332.2021.9453925}, pages = {1605 -- 1614}, year = {2021}, abstract = {During the Covid-19 pandemic, vocational colleges, universities of applied science and technical universities often had to cancel laboratory sessions requiring students' attendance. These above of all are of decisive importance in order to give learners an understanding of theory through practical work.This paper is a contribution to the implementation of distance learning for laboratory work applicable for several upper secondary educational facilities. Its aim is to provide a paradigm for hybrid teaching to analyze and control a non-linear system depicted by a tank model. For this reason, we redesign a full series of laboratory sessions on the basis of various challenges. Thus, it is suitable to serve different reference levels of the European Qualifications Framework (EQF).We present problem-based learning through online platforms to compensate the lack of a laboratory learning environment. With a task deduced from their future profession, we give students the opportunity to develop own solutions in self-defined time intervals. A requirements specification provides the framework conditions in terms of time and content for students having to deal with the challenges of the project in a self-organized manner with regard to inhomogeneous previous knowledge. If the concept of Complete Action is introduced in classes before, they will automatically apply it while executing the project.The goal is to combine students' scientific understanding with a procedural knowledge. We suggest a series of remote laboratory sessions that combine a problem formulation from the subject area of Measurement, Control and Automation Technology with a project assignment that is common in industry by providing extracts from a requirements specification.}, language = {en} } @inproceedings{HoeflingSchirraSpohretal.2013, author = {Hoefling, J. and Schirra, Julian and Spohr, A. and Sch{\"a}fer, D.}, title = {Induced drag computation with wake model schemes for highly non-planar wing systems}, series = {Deutscher Luft- und Raumfahrtkongress 2013 : 10.9. - 12.9.2013, Stuttgart}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2013 : 10.9. - 12.9.2013, Stuttgart}, publisher = {Dt. Ges. f{\"u}r Luft- und Raumfahrt}, address = {Bonn}, organization = {Deutscher Luft- und Raumfahrtkongress <62, 2013, Stuttgart>}, pages = {1 -- 10}, year = {2013}, language = {en} } @article{HodelOrzatiMarsoetal.2000, author = {Hodel, U. and Orzati, A. and Marso, M. and Homann, O. and Fox, A. and Hart, A. v. d. and F{\"o}rster, Arnold and Kordos, P. and L{\"u}th, H.}, title = {A novel InAlAs/InGaAs layer structure for monolithically integrated photoreceiver}, series = {Conference Proceedings: 2000 International Conference on Indium Phosphide and related materials}, journal = {Conference Proceedings: 2000 International Conference on Indium Phosphide and related materials}, publisher = {IEEE Service Center}, address = {Piscataway, NJ}, isbn = {0-7803-6320-5}, pages = {466 -- 469}, year = {2000}, language = {en} } @article{HirschfeldLustfeldReisseletal.2010, author = {Hirschfeld, J. A. and Lustfeld, H. and Reißel, Martin and Steffen, B.}, title = {A novel scheme for precise diagnostics and effective stabilization of currents in a fuel cell stack}, series = {International Journal of Energy Research. 34 (2010), H. 3}, journal = {International Journal of Energy Research. 34 (2010), H. 3}, isbn = {0363-907X}, pages = {293 -- 301}, year = {2010}, language = {en} } @article{HirschfeldLustfeldReisseletal.2010, author = {Hirschfeld, J. A. and Lustfeld, H. and Reißel, Martin and Steffen, B.}, title = {Tomographic diagnostics of current distributions in a fuel cell stack}, series = {International Journal of Energy Research}, volume = {34}, journal = {International Journal of Energy Research}, number = {3}, isbn = {0363-907X}, pages = {284 -- 292}, year = {2010}, language = {en} } @article{Hirschberg1994, author = {Hirschberg, Rainer}, title = {Computer-Aided-Engineering in der Technischen Geb{\"a}udeausr{\"u}stung}, series = {computer spezial (1994)}, journal = {computer spezial (1994)}, pages = {32 -- 37}, year = {1994}, language = {en} } @article{Hirschberg2008, author = {Hirschberg, Rainer}, title = {Decentral pumps in heating systems - a new hydraulic approac}, series = {1st International Rotating Equipment Conference - Pumps and Compressors, 9th Pump Users International Forum, 9. Internationales Pumpenanwenderforum, Final Report, D{\"u}sseldorf, DE, 28.-29. Oct, 2008}, journal = {1st International Rotating Equipment Conference - Pumps and Compressors, 9th Pump Users International Forum, 9. Internationales Pumpenanwenderforum, Final Report, D{\"u}sseldorf, DE, 28.-29. Oct, 2008}, publisher = {-}, pages = {1 -- 10}, year = {2008}, language = {en} } @inproceedings{HirschAhlbrinkPitzPaaletal.2011, author = {Hirsch, Tobias and Ahlbrink, Nils and Pitz-Paal, Robert and Teixeira Boura, Cristiano Jos{\´e} and Hoffschmidt, Bernhard and Gall, Jan and Abel, Dirk and Nolte, Vera and Wirsum, Manfred and Andersson, Joel and Diehl, Moritz}, title = {Dynamic simulation of a solar tower system with open volumetric receiver - a review on the ViCERP project}, series = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain}, booktitle = {SolarPACES 2011 : concentrating solar power and chemical energy systems : 20 - 23 September, 2011, Granada, Spain}, address = {Granada}, pages = {1 CD-ROM}, year = {2011}, language = {en} } @inproceedings{HirschAbelBohnetal.2009, author = {Hirsch, Tobias and Abel, Dirk and Bohn, Dieter and Diehl, Moritz and Hoffschmidt, Bernhard and Pitz-Paal, Robert}, title = {The Virtual Institute for Central Receiver Power Plants - vICERP}, series = {SolarPACES 2009 : electricity, fuels and clean water powered by the sun ; 15 - 18 September 2009, Berlin, Germany ; the 15th SolarPACES conference ; proceedings}, booktitle = {SolarPACES 2009 : electricity, fuels and clean water powered by the sun ; 15 - 18 September 2009, Berlin, Germany ; the 15th SolarPACES conference ; proceedings}, publisher = {Deutsches Zentrum f. Luft- u. Raumfahrt}, address = {Stuttgart}, isbn = {9783000287558}, pages = {1 CD-ROM}, year = {2009}, language = {en} } @inproceedings{HirschWahle1978, author = {Hirsch, G. and Wahle, Michael}, title = {Design criteria for dynamic vibration absorbers with regard to the nonproportional damping}, series = {Proceedings / The Third US National Conference on Wind Engineering Research, February 26 - March 1, 1978, University of Florida, Gainesville}, booktitle = {Proceedings / The Third US National Conference on Wind Engineering Research, February 26 - March 1, 1978, University of Florida, Gainesville}, editor = {Leadon, Bernhard M.}, publisher = {Univ. of Florida, Div. of Continuing Education Publ.}, address = {Gainsville, Fla.}, pages = {507 -- 510}, year = {1978}, language = {en} }