Refine
Year of publication
- 2024 (20) (remove)
Document Type
- Doctoral Thesis (8)
- Article (7)
- Part of Periodical (3)
- Master's Thesis (2)
Keywords
- Grounded Theory (2)
- Aktivität (1)
- Anabaena sp. (1)
- CAT (1)
- Calothrix desertica (1)
- Carnivora (1)
- Disney (1)
- Forschen in Koblenz (1)
- Inhaltsanalyse (1)
- Junges Forschen (1)
Institute
- Institut für Integrierte Naturwissenschaften, Abt. Chemie (3)
- Zentrale Einrichtungen (3)
- Institut für Integrierte Naturwissenschaften, Abt. Physik (2)
- Institut für Musikwissenschaft und Musikpädagogik (2)
- Institut für Psychologie (2)
- Fachbereich 4 (1)
- Institut für Anglistik und Amerikanistik (1)
- Institut für Informatik (1)
- Institut für Integrierte Naturwissenschaften, Abt. Biologie (1)
- Institut für Pflegewissenschaften (1)
In dieser wiederkehrenden Zeitschriftenreihe wollen wir die Arbeit junger Wissenschaftlerinnen und Wissenschaftler an der Universität Koblenz kommunizieren und Studierenden Austausch- und Publikationsmöglichkeiten für den wissenschaftlichen Werdegang eröffnen.
In dieser Ausgabe:
Christin Robrecht: Helfen kommt nach der Flut: Über die Ambivalenz situativ-nichtalltäglicher Dynamiken im Kontext der Flutkatastrophe im Ahrtal
Theresa Josephine Fischbach: Kontrollüberzeugung und Job Strain: Eine empirische Analyse verschiedener Ausprägungen von Job Strain aufgrund individueller Unterschiede der Kontrollüberzeugung
Rebekka Jachmig: Der Ukraine-Krieg im rechtspopulistischen Diskurs: Eine Analyse der Deutungsmuster von AfD-Politiker*innen
Hanna Schroer: Am Rande Galliens, inmitten der Welt: Eine Comicanalyse interkultureller Fremderfahrung am Beispiel der Comicserie Asterix
Lisa-Marie Schwab: Koloniale Spuren des Handels in Koblenz: Eine kritische Aufarbeitung
Jana Semrau: Okey-Doke: Political Critique in Spike Lee’s "BlacKkKlansman" (2018)
Anna Mira Olszewski: Of Wardrobes and Closets. A Lesson Plan on "Simon vs. Homo Sapiens Agenda" (2015) by Becky Albertalli
Marina Neuwert: Projektive Kommunikation von (Berufs-)Identität: Promotionsinteresse und Zukunftskarrieren bei Lehramtsstudierenden
Jan-Lukas Löwen: Zur Möglichkeit und Notwendigkeit der ästhetischen Erfahrung im Literaturunterricht
Malin Britz: Wearable Devices: Ein systemisches Review
Nanoparticles are sensitive and robust systems; they are particularly reactive due to their large surface area and have properties that the bulk material does not have. At the same time, the production of nanoparticles is challenging, because even with the same parameters and conditions, the parameters can vary slightly from run to run. In order to avoid this, this work aims to develop a continuous synthesis in the microjet reactor for nanoceria. The aim is to obtain monodisperse nanoparticles that can be used in biosensors.
This work focuses on two precipitation syntheses with the intermediate steps of cerium carbonate and cerium hydroxide, as well as a microemulsion synthesis for the production of nanoceria. The cerium oxide nanoparticles are compared using different characterisation and application methods. The synthesised nanoparticles will be characterised with respect to their size, stability, chemical composition and catalytic capabilities, by electron microscopy, X-ray diffraction, Raman spectroscopy and photoelectron spectroscopy.
The biosensor systems to evaluate the nanoceria are designed to detect histamine and glucose or hydrogen peroxide, which are resulting from the oxidation of histamine and glucose. Hydrogen peroxide and glucose are detected by an electrochemical sensor and histamine by a colorimetric sensor system.
The title compound, [Fe(C5H5)(C21H24NO2)], which is produced by the oxidation of 1-(4-tert-butylphenyl)-2-ethyl-3-ferrocenylpyrrole, crystallizes as a racemic mixture in the centrosymmetric space group P21/n. The central heterocyclic pyrrole ring system subtends dihedral angles of 13.7 (2)° with respect to the attached cyclopentadienyl ring and of 43.6 (7)° with the major component of the disordered phenyl group bound to the N atom. The 4-tert-butylphenyl group, as well as the non-substituted Cp ring are disordered with s.o.f. values of 0.589 (16) and 0.411 (16), respectively. In the crystal, molecules with the same absolute configuration are linked into infinite chains along the b-axis direction by O—H···O hydrogen bonds between the hydroxy substituent and the carbonyl O atom of the adjacent molecule.
The production of isolated metallic nanoparticles with multifunctionalized properties, such as size and shape, is crucial for biomedical, photocatalytic, and energy storage or remediation applications. This study investigates the initial particle formations of gold nanoparticles (AuNPs) bioproduced in the cyanobacteria Anabaena sp. using high-resolution transmission electron microscopy images for digital image analysis. The developed method enabled the discovery of cerium nanoparticles (CeNPs), which were biosynthesized in the cyanobacteria Calothrix desertica. The particle size distributions for AuNPs and CeNPs were analyzed. After 10 h, the average equivalent circular diameter for AuNPs was 4.8 nm, while for CeNPs, it was approximately 5.2 nm after 25 h. The initial shape of AuNPs was sub-round to round, while the shape of CeNPs was more roundish due to their amorphous structure and formation restricted to heterocysts. The local PSDs indicate that the maturation of AuNPs begins in the middle of vegetative cells and near the cell membrane, compared to the other regions of the cell.
Herein, the particle size distributions (PSDs) and shape analysis of in vivo bioproduced particles from aqueous Au3+ and Eu3+ solutions by the cyanobacterium Anabaena sp. are examined in detail at the nanoscale. Generally, biosynthesis is affected by numerous parameters. Therefore, it is challenging to find the key set points for generating tailored nanoparticles (NPs). PSDs and shape analysis of the Au and Eu-NPs were performed with ImageJ using high-resolution transmission electron microscopy (HR-TEM) images. As the HR-TEM image analysis reflects only a fraction of the detected NPs within the cells, additional PSDs of the complete cell were performed to determine the NP count and to evaluate the different accuracies. Furthermore, local PSDs were carried out at five randomly selected locations within a single cell to identify local hotspots or agglomerations. The PSDs show that particle size depends mainly on contact time, while the particle shape is hardly affected. The particles formed are distributed quite evenly within the cells. HR-PSDs for Au-NPs show an average equivalent circular diameter (ECD) of 8.4 nm (24 h) and 7.2 nm (51 h). In contrast, Eu-NPs preferably exhibit an average ECD of 10.6 nm (10 h) and 12.3 nm (244 h). Au-NPs are classified predominantly as “very round” with an average reciprocal aspect ratio (RAR) of ~0.9 and a Feret major axis ratio (FMR) of ~1.17. Eu-NPs mainly belong to the “rounded” class with a smaller RAR of ~0.6 and a FMR of ~1.3. These results show that an increase in contact time is not accompanied by an average particle growth for Au-NPs, but by a doubling of the particle number. Anabaena sp. is capable of biosorbing and bioreducing dissolved Au3+ and Eu3+ ions from aqueous solutions, generating nano-sized Au and Eu particles, respectively. Therefore, it is a low-cost, non-toxic and effective candidate for a rapid recovery of these sought-after metals via the bioproduction of NPs with defined sizes and shapes, providing a high potential for scale-up.
Empirical studies in software engineering use software repositories as data sources to understand software development. Repository data is either used to answer questions that guide the decision-making in the software development, or to provide tools that help with practical aspects of developers’ everyday work. Studies are classified into the field of Empirical Software Engineering (ESE), and more specifically into Mining Software Repositories (MSR). Studies working with repository data often focus on their results. Results are statements or tools, derived from the data, that help with practical aspects of software development. This thesis focuses on the methods and high order methods used to produce such results. In particular, we focus on incremental methods to scale the processing of repositories, declarative methods to compose a heterogeneous analysis, and high order methods used to reason about threats to methods operating on repositories. We summarize this as technical and methodological improvements. We contribute the improvements to methods and high-order methods in the context of MSR/ESE to produce future empirical results more effectively. We contribute the following improvements. We propose a method to improve the scalability of functions that abstract over repositories with high revision count in a theoretically founded way. We use insights on abstract algebra and program incrementalization to define a core interface of highorder functions that compute scalable static abstractions of a repository with many revisions. We evaluate the scalability of our method by benchmarks, comparing a prototype with available competitors in MSR/ESE. We propose a method to improve the definition of functions that abstract over a repository with a heterogeneous technology stack, by using concepts from declarative logic programming and combining them with ideas on megamodeling and linguistic architecture. We reproduce existing ideas on declarative logic programming with languages close to Datalog, coming from architecture recovery, source code querying, and static program analysis, and transfer them from the analysis of a homogeneous to a heterogeneous technology stack. We provide a prove-of-concept of such method in a case study. We propose a high-order method to improve the disambiguation of threats to methods used in MSR/ESE. We focus on a better disambiguation of threats, operationalizing reasoning about them, and making the implications to a valid data analysis methodology explicit, by using simulations. We encourage researchers to accomplish their work by implementing ‘fake’ simulations of their MSR/ESE scenarios, to operationalize relevant insights about alternative plausible results, negative results, potential threats and the used data analysis methodologies. We prove that such way of simulation based testing contributes to the disambiguation of threats in published MSR/ESE research.
Reducing gender bias in STEM is key to generating more equality and contributing to a more balanced workforce in this field. Spatial ability and its components are cognitive processes crucial to success in STEM education and careers. Significant gender differences have consistently been found in mental rotation (MR), the ability to mentally transform two- and three-dimensional objects. The aim of this pilot study is to examine factors in psychological assessment which may contribute to gender differences in MR performance. Moreover, findings will inform the development of the new approaches to assessment using computer adaptive testing (CAT). (1) Background: The study examines the impact of emotional regulation on MR performance in primary school children whose mean age was 9.28 years old. (2) Methods: Skin conductance was measured to assess the impact of emotional reactivity (ER) on performance during an MR task. (3) Results: Patterns of ER influence response time (RT) on specific items in the task. (4) Conclusions: Identifying the effects of emotional arousal and issues of test construction such as stereotyped stimuli and item difficulty in tests of spatial ability warrants ongoing investigation. It is vital to ensure that these factors do not compromise the accurate measurement of performance and inadvertently contribute to the gender gap in STEM.
Sind Menschen von einer Pflegebedürftigkeit in Deutschland betroffen, so regelt der durch § 14 SGB XI festgeschriebene Pflegebedürftigkeitsbegriff den Zugang zu Leistungen der Pflegeversicherung. Der Pflegebedürftigkeitsbegriff ist dabei ein normativ gesetzter und basiert bislang nicht auf empirischen Studien aus dem Bereich der Pflege und der Pflegewissenschaft. Durch seine gesetzliche Fundierung lenkt er die Bedingungen und Strukturen, unter welchen Pflegeleistungen in Deutschland von Pflegefachpersonen erbracht werden. Weiterhin ist davon auszugehen, dass die Pflegefachpersonen durch ihre professionelle Sozialisierung einen fachlichen Fokus auf das Konstrukt der Pflegebedürftigkeit legen, welcher sich vom Pflegebedürftigkeitsbegriff unterscheidet und strukturell nicht in die Leistungsbemessung einfließt. Daraus ergeben sich Aspekte einer pflegerischen Unter- und Überversorgung.
Die vorliegende Ph.D.-Thesis verfolgt das Anliegen, die Herausforderungen des Pflegebedürftigkeitsbegriffs in Deutschland aufzuzeigen, indem die Aspekte der Pflegebedürftigkeit von Pflegefachpersonen im ambulanten Setting im Hinblick auf deren Interaktion mit pflegebedürftigen Menschen empirisch erfasst und zu einem theoretischen Konzept ausgearbeitet werden. Zur methodischen Bearbeitung des Forschungsinteresses werden problemzzentrierte Interviews mit ambulanten Pflegefachpersonen geführt, die mit Rückbezug auf den Symbolischen Interaktionismus nach Herbert Blumer unter methodologischen und methodischen Gesichtspunkten mittels einer Grounded Theory nach Kathy Charmaz sowie Juliet Corbin und Anselm Strauss erhoben und ausgewertet werden. Dabei kommt ein reflexives-konstruktivistisches Forschen und Schreiben als Konsequenz der epistemologisch-methodologischen Fundierung der Autorin zur Anwendung.
Die erarbeitete Theorie beschreibt die Herausforderungen der Pflegebedürftigkeit aus Sicht der befragten Pflegefachpersonen. So werden in der Kernkategorie Aushandlungsprozesse in den Bereichen Nähe und Distanz, Anwaltschaft und Verantwortungsüberlassung sowie Ethos und Technokratie beschrieben. Sämtliche Aspekte zeigen auf, inwiefern der gesetzliche Pflegebedürftigkeitsbegriff zu Herausforderungen innerhalb der pflegerischen Arbeit führt. Die Ph.D.-Thesis liefert mit ihren Ergebnissen einen Beitrag zur Einordnung und Relevanz pflegerischer Beziehungsarbeit im Hinblick auf herrschende Rahmenbedingungen der Pflegebedürftigkeit und zeigt auf, inwiefern sich Interaktion und Kommunikation der Akteur*innen vor dem Anspruch individueller Pflege und dem deutschen ambulanten Pflegesystem wechselseitig bedingen. Sie liefert damit einen professionell und empirisch begründeten Ansatz für die Einschätzung und Bearbeitung von pflegefachlich erlebter Pflegebedürftigkeit.