As a contribution to addressing the challenges posed by climate change, acoustic ecology, and in particular the study of changes in soundscapes, provides an opportunity to better understand and subsequently manage climate change. This paper focuses on the development of new spectrogram-based analysis methods to expand the possibilities of comparative analysis of soundscapes. The database to be analysed with the new methods is provided by the WikliNathi project, a long-term monitoring study to investigate the sonic changes of populations of living organisms as well as geophone and anthropophone sounds in a nature reserve. The developed methods of analysis will be presented in detail. Selected audio recordings are analysed for changes in the sounds of great tits, grasshoppers and frogs from 2018 to 2023 using spectral flatness, temporal flatness and onset detection in aligned time-frequency regions. The evaluation of the results shows that the proposed new methods can be used to obtain more detailed and complementary results in future studies as part of this and other bioacoustic projects.

Laser sintering, also known as powder bed fusion—laser beam, employs a laser to sinter-powdered polymeric materials, such as Polyamide 12. Despite the process, a significant portion of the powder remains unsintered. However, due to elevated temperatures, material degradation occurs, altering its chemical characteristics. Industrially, a common practice involves utilizing a mixture of virgin and aged powder, with the latter having undergone multiple thermal cycles without sintering. Developing an effective powder recycling methodology is fundamental for fully realizing the potential of Polyamide 12. This work focuses the attention on reused powder to manufacture parts in Polyamide 12 through selective laser sintering and evaluates the correlation between the properties of reused powder and the strength of manufactured part through six consecutive printing processes. To achieve this, a wide experimental approach was planned and developed to arrive to establish a clear relationship between the degree of crystallinity of the powder and the ultimate tensile strength of the part made from that powder. This relationship may be used to choose the kind of powder based on the strength required to the manufactured part in exercise. At the same time, if only a kind of powder is available, this relationship allows to predict the mechanical strength of the part manufactured.

In this chapter, an overview is given of the research work during the years 2007 until 2016 in the field of tolerance analysis, optimization and synthesis of mechanisms ([11] and [17]). At the beginning, the challenges related to mechanisms are highlighted, especially the time-dependent behaviour of a mechanism during its operation and the different kinds of deviation occuring during the production and the operation of the mechanism. After that, the integrated approach for the statistical tolerance analysis of mechanisms is described. This approach is then enlarged to a complete tolerance analysis, optimization and synthesis approach before its applicability is demonstrated in a case study. The chapter will end with a summary.

Diese Studie beschreibt die Entwicklung eines betriebsunabhängigen Simulationsmodells für elektrifizierte Druckgießereien, die ihren Energiebedarf mit Hilfe eines Smart Grid Systems decken. Das Modell verwendet reale Wetter- und Börsenstrompreisdaten für den Simulationszeitraum. Mit Hilfe des Modells können die Stromkosten für eine Produktion zu einem bestimmten Zeitpunkt (Tages- und Jahreszeit) sowie die Wirtschaftlichkeit verschiedener PV-Anlagen- und Stromspeichervarianten ermittelt und verglichen werden. Zudem ermöglicht es die Untersuchung des Anteils der verschiedenen Energieträger für die jeweilige Konfiguration. Dies kann mit Hilfe des Modells für Standorte in ganz Deutschland durchgeführt werden. Darüber hinaus werden in dieser Arbeit beispielhafte Simulationsstudien vorgestellt, die den breiten Anwendungsbereich des Modells aufzeigen. Aus den Ergebnissen kann ein erster Überblick über Einsparungs- und Optimierungsmöglichkeiten gewonnen werden. Perspektivisch stellt das Modell eine Grundlage dar, um mittels simulationsgestützter Optimierung optimale Anlagenlayouts und Produktionszeitpunkte zu ermitteln.

In diesem Artikel wird die Frage gestellt, ob die von Alfred North Whitehead benannte "Bifurkation der Natur" in der Mensch-Computer-Interaction (MCI) vorkommt. Speziell geht es um die Entwicklung von Schnittstellen für digitale Musikinstrumente. Die Bedeutung des Begriffs der Bifurkation wird zunächst erläutert. Die Methode zur Beantwortung der Fragestellung erfolgt durch die Analyse, inwieweit sich die mit der Bifurkation der Natur einhergehenden Prozesse in Entwicklungsprozessen von musikalischen Interfaces wiederfinden. Das Ergebnis zeigt, dass die Bifurkation der Natur in der Entwicklung von musikalischen Interfaces zu finden ist. Daraus ergeben sich eine Reihe von Fragen, von denen einige dargelegt und mögliche Folgen diskutiert werden.

Purpose - This study aims to address challenges in the Laser Powder Bed Fusion process of polymers, focusing on the considerable amount of unsintered powder left post-printing. The objective is to understand the altered properties of this powder and find solutions to improve the process, reduce waste, and explore reusing reprocessed powder.

Design/methodology/approach - A novel methodology is employed to generate reprocessed powder without traditional printing, reducing time, cost, and waste. The approach mimics the aging effects during the printing process, providing insights into particle size distribution and thermal behavior.

Findings - Results reveal insights into artificial aging, showing an 8.2% decrease in particle size (60.256 - 69.183 μm) and a 9.1% increase in particle size (17.378 - 19.953 μm) compared to unsintered powder. Thermal behavior closely mirrors used powders, with variations in enthalpy of fusion (-0.55% to 2.69%) and degree of crystallinity (0.19% to 2.64%). The proposed methodology produces results that differ from those due to printing under 3% from a thermal point of view. The
new process reduces the time needed for aged powder, contributing to cost savings and waste reduction.

Originality/value - The study introduces a novel method for reprocessed powder generation, deviating from traditional printing. The originality lies in artificially aging powders, providing comparable results to actual printing. This approach offers efficiency, time savings, and waste reduction in the Laser Powder Bed Fusion process, presenting a valuable avenue for further research.