@article{AlimovSviridovJenschetal.2023, author = {Alimov, Artem and Sviridov, Alexander and Jensch, Felix and Sydow, Benjamin and H{\"a}rtel, Sebastian}, title = {Additive manufacturing of hot-forming dies using laser powder bed fusion and wire arc direct energy deposition technologies}, doi = {10.3390/met13111842}, year = {2023}, abstract = {Additive technologies are now widely used for the production of complex precise parts and have high potential for the production of forming dies. In this work, hot-forming dies optimized for additive manufacturing were developed and produced with wire arc direct energy deposition (WA-DED) and laser powder bed fusion (L-PBF) technologies. The concept of lightweight hot-forming dies with a 2D-lattice structure was developed, which reduced the weight of each die by 56\%, from 14.2 kg to 6.1 kg, in production using L-PBF. Maraging/precipitation-hardened steel 17-4PH was used as an alternative to traditional hot-working steels with slightly lower mechanical properties and a much higher processability in the additive manufacturing process. The workability of the manufactured dies was confirmed by forging tests on an industrial screw press.}, subject = {Additive manufacturing; Hot-forming dies; L-PBF; WA-DED; WAAM; Additive Fertigung; Warmumformwerkzeuge; L-PBF; WA-DED; WAAM; Warmumformen; Rapid Prototyping (Fertigung); Selektives Laserschmelzen}, language = {en} } @article{TomasMarinRodriguezCalcerradaArenasCastroetal.2023, author = {Tom{\´a}s Mar{\´i}n, Sergio de and Rodr{\´i}guez-Calcerrada, J{\´e}sus and Arenas-Castro, Salvador and Prieto, Iv{\´a}n and Gonz{\´a}lez, Guillermo and Gil, Luis and Riva, Enrique G. de la}, title = {Fagus sylvatica and Quercus pyrenaica : two neighbors with few things in common}, series = {Forest Ecosystems}, volume = {10}, journal = {Forest Ecosystems}, publisher = {Beijing Foresty University}, address = {Beijing}, issn = {2197-5620}, doi = {10.1016/j.fecs.2023.100097}, year = {2023}, abstract = {The Iberian Peninsula comprises one of the largest boundaries between Mediterranean and Eurosiberian vegetation, known as sub-Mediterranean zone. This ecotone hosts many unique plant species and communities and constitutes the low-latitude (warm) margin of numerous central European species which co-occur with Mediterranean vegetation. Two of the main species found in this region are the Eurosiberian European beech (Fagus sylvatica L.) and the Mediterranean Pyrenean oak (Quercus pyrenaica Willd.). It remains unclear how the different physiological and adaptive strategies of these two species reflect their niche partitioning within a sub-Mediterranean community and to what extent phenotypic variation (intraspecific variability) is driving niche partitioning across Eurosiberian and Mediterranean species. We quantified functional niche partitioning, based on the n-dimensional hypervolume to nine traits related to resource acquisition strategies (leaf, stem and root) plus relative growth rate as an additional whole-plant trait, and the environmental niche similarity between Pyrenean oak and European beech. Further, we analyzed the degree of phenotypic variation of both target species and its relationship with relative growth rates (RGR) and environmental conditions. Plant recruitment was measured for both target species as a proxy for the average fitness. Species' functional space was highly segregated (13.09\% overlap), mainly due to differences in niche breadth (59.7\%) rather than niche replacement (25.6\%), and beech showed higher trait variability, i.e., had larger functional space. However, both species shared the environmental space, i.e., environmental niches were overlapped. Most plant traits were not related to abiotic variables or RGR, neither did RGR to plant traits. Both target species share similar environmental space, however, show notably different functional resource-use strategies, promoting a high complementarity that contributes to maintaining a high functionality in sub-Mediterranean ecosystems. Therefore, we propose that conservation efforts be oriented to preserve both species in these habitats to maximize ecosystem functionality and resilience.}, subject = {Environmental niche; European beech; Forest dynamics; Functional niche; Pyrenean oak; {\"O}kologische Nische; Europ{\"a}ische Buche; Walddynamik; Funktionelle Nische; Pyren{\"a}en-Eiche; Iberische Halbinsel; {\"O}koton; {\"O}kologische Nische; Rotbuche; Pyren{\"a}eneiche; Artenschutz; {\"O}kosystem}, language = {en} } @article{TomasMarinGalanDiazRodriguezCalcerradeetal.2023, author = {Tom{\´a}s Mar{\´i}n, Sergio de and Gal{\´a}n D{\´i}az, Javier and Rodr{\´i}guez-Calcerrade, J{\´e}sus and Prieto, Iv{\´a}n and Riva, Enrique G. de la}, title = {Linking functional composition moments of the sub-mediterranean ecotone with environmental drivers}, series = {Frontiers in Plant Science}, volume = {14}, journal = {Frontiers in Plant Science}, publisher = {Frontiers}, address = {Lausanne}, issn = {1664-462X}, doi = {10.3389/fpls.2023.1303022}, year = {2023}, abstract = {Functional trait-based approaches are extensively applied to the study of mechanisms governing community assembly along environmental gradients. These approaches have been classically based on studying differences in mean values among species, but there is increasing recognition that alternative metrics of trait distributions should be considered to decipher the mechanisms determining community assembly and species coexistence. Under this framework, the main aim of this study is to unravel the effects of environmental conditions as drivers of plant community assembly in sub-Mediterranean ecotones. We set 60 plots in six plant communities of a sub-Mediterranean forest in Central Spain, and measured key above- and belowground functional traits in 411 individuals belonging to 19 species, along with abiotic variables. We calculated community-weighted mean (CWM), skewness (CWS) and kurtosis (CWK) of three plant dimensions, and used maximum likelihood techniques to analyze how variation in these functional community traits was driven by abiotic factors. Additionally, we estimated the relative contribution of intraspecific trait variability and species turnover to variation in CWM. The first three axes of variation of the principal component analyses were related to three main plant ecological dimensions: Leaf Economics Spectrum, Root Economics Spectrum and plant hydraulic architecture, respectively. Type of community was the most important factor determining differences in the functional structure among communities, as compared to the role of abiotic variables. We found strong differences among communities in their CWMs in line with their biogeographic origin (Eurosiberian vs Mediterranean), while differences in CWS and CWK indicate different trends in the functional structure among communities and the coexistence of different functional strategies, respectively. Moreover, changes in functional composition were primarily due to intraspecific variability. We observed a high number of strategies in the forest with the different communities spreading along the acquisitive-conservative axis of resource-use, partly matching their Eurosiberian-Mediterranean nature, respectively. Intraspecific trait variability, rather than species turnover, stood as the most relevant factor when analyzing functional changes and assembly patterns among communities. Altogether, our data support the notion that ecotones are ecosystems where relatively minor environmental shifts may result in changes in plant and functional composition.}, subject = {Mixed-species forest; Sub-mediterranean; Ecotone; Functional structure; Intraspecific variability; {\"O}koton; Funktionelle Struktur; Intraspezifische Variabilit{\"a}t; Artengemischter Wald; Submediterran; Spanien; Meseta; {\"O}koton; Wald; Pflanzengesellschaft; Umweltver{\"a}nderung; Maximum-Likelihood-Technik}, language = {en} } @article{DikraFellahBarilleetal.2023, author = {Dikra, Bouras and Fellah, Mamoun and Barille, Regis and Weiß, Sabine and Samad, Mohammed Abdul and Alburaikan, Alhanouf and Khalifa, Hamiden Abd El-Wahed and Obrosov, Aleksei}, title = {Improvement of photocatalytic performance and sensitive ultraviolet photodetectors using AC-ZnO/ZC-Ag2O/AZ-CuO multilayers nanocomposite prepared by spin coating method}, series = {Journal of science: advanced materials and devices}, volume = {9}, journal = {Journal of science: advanced materials and devices}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2468-2179}, doi = {10.1016/j.jsamd.2023.100642}, year = {2023}, abstract = {Morphological and optical properties of a multilayer film (CAZO/CZAO/ZACO) prepared by spin-coating method and deposited on a glass substrate were evaluated. The study was initially carried out for each layer, individually and then as a multilayer subsequently. Structural properties using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), infrared spectra (IR) and X-ray photoelectron Spectroscopy (XPS) showed the presence of three phases of zinc, copper and silver oxides at different levels. The CZAO sample observed with scanning electron microscope (SEM) showed an excellent porous surface with a large deformation in the multilayer configuration. Doping with zinc and copper in the silver crystal lattice improved the crystal structure and reduced the optical energy gap, thus increasing the optical absorbance and refractive index. The dielectric constants and showed an increase in the optical polarization values for lower photonic energies. The maximum degradation rate for photocatalysts of methylene blue was 89 \% for a 5-h exposure period with CAZO/CZAO/ZACO while it reached 71 \% for the CZAO sample during the same time period. The sensitivity of samples to light proved that the presence of ultraviolet radiation increases the number of holes trapped by oxygen ions and causes more free electrons and contribute to a better production of photocurrent than in darkness.}, subject = {Multilayer CAZO/CZAO/ZACO; Photocatalysis; Photodetector; Nanostructures; Nanocomposites; Multilagenbeschichtung CAZO/CZAO/ZACO; Rotationsbeschichtung; Photokatalyse; Nanostrukturen; Nanokompositen; Nanokomposit; Mehrschichtsystem; Beschichtung; Fotokatalyse; Photodetektor}, language = {en} } @article{Yadollahi2020, author = {Yadollahi, Solmaz}, title = {Reflections on the past and future of urban conservation in Iran}, series = {Built heritage}, volume = {4}, journal = {Built heritage}, number = {19}, publisher = {Springer}, address = {Heidelberg}, issn = {2662-6802}, doi = {10.1186/s43238-020-00019-1}, year = {2020}, abstract = {The material authenticity of cultural heritage has been questioned by societies in which the modern paradigm of conservation has not developed from within the native culture. This paper examines the philosophical and practical traditions in Iran regarding the materiality and authenticity of past structures. By reviewing the emergence of the Western conservation paradigm in Iran, this paper highlights two key factors: the rapidness of this paradigm shift and the remarkable contradiction between the new and old paradigms. By borrowing the Deleuzo-Guattarian concept of a 'body without organs' (BwO), this paper problematises the rapidness and radicality of the paradigm shift in Iran. It suggests exploring the under-investigated possibilities between the pre-modern and modern paradigms to address the gap between native circumstances and Western standards.}, subject = {Cultural heritage; Authenticity; Iran; Conservation; Kulturelles Erbe; Authentizit{\"a}t; Denkmalschutz; Iran; Kulturerbe; Stadt; Denkmalpflege; Denkmalschutz; Authentizit{\"a}t; Materialit{\"a}t}, language = {en} } @book{Kuennemann2022, author = {K{\"u}nnemann, Andreas}, title = {Existenz- und Regularit{\"a}tstheorie der zweidimensionalen Variationsrechnung mit Anwendungen auf das Plateausche Problem f{\"u}r Fl{\"a}chen vorgeschriebener mittlerer Kr{\"u}mmung}, publisher = {Springer}, address = {Heidelberg}, isbn = {978-3-658-41640-9}, doi = {10.1007/978-3-658-41641-6}, publisher = {BTU Cottbus - Senftenberg}, pages = {247}, year = {2022}, abstract = {Die vorliegende Arbeit behandelt f{\"u}r eine breite Klasse zweidimensionaler Variationsprobleme eine Existenz- und Regularit{\"a}tstheorie, die der L{\"o}sung von Randwertproblemen partieller Differentialgleichungssysteme dient. Dabei werden bekannte Ergebnisse gr{\"u}ndlich untersucht und umfassend aufgearbeitet. Teilweise wird eine geeignete Anpassung der Voraussetzungen einiger Resultate vorgenommen. Speziell wird die Theorie auf das Plateausche Problem f{\"u}r Fl{\"a}chen vorgeschriebener mittlerer Kr{\"u}mmung im R3 angewendet. Eingangs wird das Konzept der direkten Methoden der Variationsrechnung erl{\"a}utert. {\"U}ber einen fundamentalen Satz zur schwachen Unterhalbstetigkeit von Funktionalen wird die Existenz eines Minimierers f{\"u}r eine breite Klasse von Variationsproblemen nachgewiesen. Da die Existenztheorie in Sobolev-R{\"a}umen agiert, sind Untersuchungen zur Regularit{\"a}t eines Minimierers notwendig. Im Rahmen der Regularit{\"a}tstheorie wird das Dirichletsche Wachstumstheorem von Morrey gezeigt, welches ein hinreichendes Kriterium f{\"u}r die H{\"o}lder-Stetigkeit einer Funktion X ∈ W1,2(G) liefert. Zum Nachweis der Anwendbarkeit des Dirichletschen Wachstumstheorems auf einen Minimierer wird ein Wachstumslemma verwendet. Dabei werden eine Verkn{\"u}pfung des Dirichlet-Integrals mit Fourierreihen sowie das Dirichlet- Integral der harmonischen Ersetzung einer Funktion mit L2-Randwerten genutzt. Infolgedessen ergibt sich die H{\"o}lder-Stetigkeit im Inneren f{\"u}r einen Minimierer. Zudem wird die Stetigkeit des Minimierers bis zum Rand gezeigt, sodass die Existenz eines stetigen Minimierers f{\"u}r eine breite Klasse von Variationsproblemen gesichert ist. Anschließend erfolgt die Berechnung der ersten Variation sowie die damit verbundene Herleitung der schwachen Euler-Lagrange-Gleichung, welche eine Beziehung zur L{\"o}sungstheorie von Differentialgleichungen im Sinne des Dirichletschen Prinzips herstellt. Ausgehend von der schwachen Euler-Lagrange-Gleichung wird die H{\"o}lder-Stetigkeit der ersten Ableitungen eines Minimierers bewiesen. F{\"u}r die L{\"o}sung von Randwertproblemen mit partiellen Differentialgleichungen zweiter Ordnung mithilfe der Variationsrechnung ist der Nachweis stetiger zweiter Ableitungen des Minimierers notwendig. Dabei wird der Fokus auf sogenannte Minimierer vom Poissonschen Typ gelegt. Eine C2,σ-Rekonstruktion, die auf der Schaudertheorie basiert, liefert in diesem Fall die gew{\"u}nschte Regularit{\"a}t. In Anwendung dessen werden das Randwertproblem harmonischer Abbildungen in Riemannschen R{\"a}umen sowie das Dirichletproblem des H-Fl{\"a}chen-Systems behandelt, indem jeweils ein geeignetes Variationsproblem aufgestellt wird. Als Erweiterung des Dirichletproblems des H-Fl{\"a}chen-Systems wird das allgemeine Plateausche Problem f{\"u}r Fl{\"a}chen vorgeschriebener mittlerer Kr{\"u}mmung mit den erarbeiteten Methoden der Variationsrechnung untersucht. Zudem wird das Plateausche Problem f{\"u}r Fl{\"a}chen vorgeschriebener mittlerer Kr{\"u}mmung in Kugeln, in Zylindern sowie insbesondere im Einheitskegel gel{\"o}st. Insgesamt wird eine ausf{\"u}hrliche, in sich geschlossene und gut verst{\"a}ndliche Existenzund Regularit{\"a}tstheorie der zweidimensionalen Variationsrechnung zur Behandlung von Randwertproblemen partieller Differentialgleichungssysteme dargestellt, welche sich in besonderer Weise bei der L{\"o}sung des Plateauschen Problems f{\"u}r Fl{\"a}chen vorgeschriebener mittlerer Kr{\"u}mmung entfaltet.}, subject = {Variationsrechnung; Variationsrechnung; Dimension 2; Mittlere Kr{\"u}mmung; Plateau-Problem; Partielle Differentialgleichungen; Plateausches Problem; Regularit{\"a}tstheorie; Morrey; Variation calculation; Partial differential equations; Plateau problem; Regularity theory}, language = {de} } @article{BoellmannMartienssen2024, author = {B{\"o}llmann, J{\"o}rg and Martienssen, Marion}, title = {Seasonal variability of cultivable nitrate-reducing and denitrifying bacteria and functional gene copy number in fresh water lake}, series = {microorganisms}, volume = {12}, journal = {microorganisms}, number = {3}, publisher = {MDPI}, address = {Basel}, issn = {2076-2607}, doi = {10.3390/microorganisms12030511}, year = {2024}, abstract = {This study describes the seasonal course of denitrifying and nitrate-reducing bacteria in a dimictic mesotrophic lake (Lake Scharm{\"u}tzelsee, Brandenburg, Germany) within a three-year period from 2011 to 2013. The bacterial cell numbers were quantified by the fluorescence microscopy, most probable number (MPN) and PCR-dependent quantification of the chromosomal 16S rDNA and of the nirS and nirK gene copy number. The highest seasonal differences (up to three orders of magnitudes) have been measured usingMPNin the epilimnion. This variation was not reflected by PCR-dependent approaches or direct microscopical enumeration. At adverse conditions (low temperature and/or low nitrate concentrations), the differences between MPN and gene copy numbers increased by up to five orders of magnitudes and decreased to one magnitude at favourable environmental conditions. These results can be explained best by an increasing ratio of viable but not cultivable (VBNC) cells or dead cells at impairing conditions. In the hypolimnion, the courses of MPN and nir gene copy numbers were similar. This can be explained by a higher feeding pressure and therefore smaller amounts of dormant cells. In the pelagial in general, the total cell numbers enumerated by either microscopical or molecular approaches were similar. In the sediment, more than 99\% of the DNA was obviously not related to viable bacteria but was rather DNA in dead cells or adsorbed to particle surfaces.}, subject = {Denitrification; Nitrite reductase; Microscopical cell number; Hypolimnion; Dimictic lake; Denitrifikation; Nitrit-Reduktase; Mikroskopische Zellzahl; Dimiktischer See}, language = {en} } @article{RosenGribat2023, author = {Rosen, Christian and Gribat, Nina}, title = {Comparing hybrid urbanisms in the global south : water delivery configurations in Peru and Ghana}, series = {Urban Planning}, volume = {8}, journal = {Urban Planning}, number = {4}, publisher = {Cogitation}, address = {Lissabon}, issn = {2183-7635}, doi = {10.17645/up.v8i4.7155}, pages = {340 -- 350}, year = {2023}, abstract = {Urban development processes in the Global South (and North) are often described as characterized by formal and informal practices of different actors and their respective material realities. In critical urban studies, the disposition for this binary conception of formal and informal urbanisms has been discussed for many years. To a certain extent, these sometimes align rather problematically with contrasting notions of the "structural" versus the "everyday." In this article, we explore an understanding of formal and informal urban practices (and respectively "structure" and "everyday") as always interrelated, and we develop a methodology for a comparative examination of such hybrid urbanisms. In doing so, we address a missing link in the surging theoretical debate on comparative/southern urbanisms, which has rarely been substantiated by methodological explorations. The adapted concept of "delivery configurations" combines analyses of actor networks, material realities, rules and regulations, discourses, and heterogenous arrays of urban practices of negotiating these. However, bringing together local particularities and structural commonalities and exploring their interrelation only provides a basis for understanding case-specific complexities. We argue that embedding the analysis in a multi-scalar comparative framework can further its analytical rather than descriptive attributes and provide deeper insights into issues such as social inequality. To illustrate our methodological contribution, we provide first insights from a comparative research project of water delivery in different neighbourhoods in the secondary cities of Sunyani (Ghana) and Arequipa (Peru). We highlight the practical challenges of comparing diverse urban contexts and examining the rather complex relationships between infrastructure delivery, urban development, and social inequality.}, subject = {Water; Hybridity; Infrastructures; Multi-scalar comparison; Peru; Ghana; Wasser; Infrastruktur; Multiskalarer Vergleich; Infrastruktureinrichtungen}, language = {en} } @article{ZschechLechowskiKuturkovaetal.2024, author = {Zschech, Ehrenfried and Lechowski, Bartlomiej and Kuturkova, Kristina and Panchenko, Luliana and Kr{\"u}ger, Peter and Clausner, Andr{\´e}}, title = {Laboratory X-ray microscopy of 3D nanostructures in the hard X-ray regime enabled by a combination of multilayer X-ray optics}, series = {Nanomaterials}, volume = {14}, journal = {Nanomaterials}, number = {2}, publisher = {MDPI}, address = {Basel}, issn = {2079-4991}, doi = {10.3390/nano14020233}, year = {2024}, abstract = {High-resolution imaging of buried metal interconnect structures in advanced microelectronic products with full-field X-ray microscopy is demonstrated in the hard X-ray regime, i.e., at photon energies > 10 keV. The combination of two multilayer optics—a side-by-side Montel (or nested Kirkpatrick-Baez) condenser optic and a high aspect-ratio multilayer Laue lens—results in an asymmetric optical path in the transmission X-ray microscope. This optics arrangement allows the imaging of 3D nanostructures in opaque objects at a photon energy of 24.2 keV (In-Kα X-ray line). Using a Siemens star test pattern with a minimal feature size of 150 nm, it was proven that features < 150 nm can be resolved. In-Kα radiation is generated from a Ga-In alloy target using a laboratory X-ray source that employs the liquid-metal-jet technology. Since the penetration depth of X-rays into the samples is significantly larger compared to 8 keV photons used in state-of-the-art laboratory X-ray microscopes (Cu-Kα radiation), 3D-nanopattered materials and structures can be imaged nondestructively in mm to cm thick samples. This means that destructive de-processing, thinning or cross-sectioning of the samples are not needed for the visualization of interconnect structures in microelectronic products manufactured using advanced packaging technologies. The application of laboratory transmission X-ray microscopy in the hard X-ray regime is demonstrated for Cu/Cu6Sn5/Cu microbump interconnects fabricated using solid-liquid interdiffusion (SLID) bonding.}, subject = {X-ray microscopy; High-resolution radiography; Nanostructure; Advanced packaging; R{\"o}ntgenmikroskopie; Hochaufl{\"o}sende Radiographie; Nanostruktur; Erweiterte Verpackung; Nanostruktur; R{\"o}ntgenmikroskopie; Radiographie}, language = {en} } @incollection{BuechnerNolteHasanietal., author = {B{\"u}chner, Steffen and Nolte, J{\"o}rg and Hasani, Alireza and Kraemer, Rolf and Lopacinsiki, Lukasz}, title = {End2End100 : communication protocol processing for ultra high data rates}, series = {Wireless 100 Gbps and beyond : architectures, approaches and findings of German Research Foundation (DFG) Priority Programme SPP1655}, booktitle = {Wireless 100 Gbps and beyond : architectures, approaches and findings of German Research Foundation (DFG) Priority Programme SPP1655}, doi = {10.26127/BTUOpen-5916}, publisher = {BTU Cottbus - Senftenberg}, pages = {359 -- 396}, abstract = {In 2012 a group of researchers proposed a basic research initiative to the German Research Foundation (DFG) as a special priority project (SPP) with the name: Wireless 100 Gbps and beyond. The main goal of this initiative was the investigation of architectures, technologies and methods to go well beyond the state of the art. The target of 100 Gbps was set far away from the (at that time) achievable 1 Gbps such that it was not possible to achieve promising results just by tuning some parameters. We wanted to find breakthrough solutions. When we started the work on the proposal we discussed the challenges to be addressed in order to advancing the wireless communication speed significantly. Having the fundamental Shannon boundary in mind we discussed how to achieve the 100 Gbps speed.}, subject = {100 Gbps; Wireless; Drahtlos; End2End100; Communication protocol processing; Kommunikations-Protokoll-Prozessierung; Drahtloses Sensorsystem; Hochfrequenztechnik; Antenne; Terahertzbereich; Energieffizienz}, language = {en} }