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MLUH-E-80_1, Falco cherrug cherrug Gray, JE, 1834, eggshell
No full textInventory No.: MLUH-E-80_1, Object: eggshell, Species: Falco cherrug cherrug Gray, JE, 1834, Preservation: complete preservation, Locality_loc.: Wolga; S. Russland, Locality today: Russia/Kazakhstan, Country: Russia/KazakhstanCollector_leg.: R. Tancré, Date: ?, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 188, Identification by: M. Schönwetter, Aquisition: 1926, Aquired from: Dr. Henrici, ex Collection: ex.Coll. Dr. Henrici; ex Coll. R. Tancré, Additional Information: 4 eggs in one box Schoenwetter questioned all the eggs being from one clutch because of differences; in the eggs; I (Jessica Dahlke) agree with hi
MLUH-E-34_1, Falco subbuteo Linnaeus, 1758, eggshell
No full textInventory No.: MLUH-E-34_1, Object: eggshell, Species: Falco subbuteo Linnaeus, 1758, Preservation: complete preservation, Locality_loc.: Mark/Brandenburg, Locality today: Germany/Poland, Country: Germany/PolandCollection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 190, Identification by: M. Schönwetter, Aquisition: 1939, Aquired from: J. F. G. Umlauff, ex Collection: ex. Coll. J. F. G. Umlauff, Additional Information: Brown eg
Triple-Q state in magnetic breathing kagome lattice
No full textMagnetic frustration in two-dimensional spin lattices with triangular motifs underpins a series of exotic states, ranging from multi-Q configurations to disordered spin glasses. The antiferromagnetic kagome lattice, characterized by its network of corner-sharing triangles, represents a paradigmatic frustrated system exhibiting macroscopic degeneracy. Expanding upon the kagomerization mechanism, we focus on the magnetic breathing kagome lattice formed by an Mn monolayer deposited on a heavy metal substrate and capped with h-BN. The Mn kagome arrangement induces pronounced magnetic frustration, as evidenced by the nearly flat bands derived from spin spiral energy calculations. Including further-neighbor interactions reveals a spin spiral energy minimum along the Γ-K line and an intriguing triple-Q state with nonzero topological charge, potentially leading to highly nonlinear Hall effects. Furthermore, the flat band properties can further give rise to an even more complex spin configuration, marked by several Q-pockets in the spin structure factor. These results present a fertile ground for advancing the study of multi-Q states and exploring emergent topological phenomena
Herausforderungen bei der Planung von Photovoltaikanlagen auf denkmalgeschützten Gebäuden
No full textLiteraturverzeichnis: Seite 29-3
Social and migration-related inequalities at the transition from primary to lower secondary education in Germany : the role of parents’ knowledge of the education system
No full textThe German school system is characterised by early tracking and a high level of differentiation and stratification, leading to diverse educational pathways associated with differing qualifications and career opportunities. In this context, knowledge of the education system should be crucial for strategically navigating the educational process. This study examined how knowledge gaps among social groups contribute to social and migration-related inequalities during the transition from primary to secondary school. Additionally, it explored whether the impact of knowledge depends on the degree to which families’ educational decisions are constrained, specifically by binding teacher recommendations. Data from Starting Cohort 2 of the National Educational Panel Study (Nstudents = 4,177) were used, taking into account parental education as well as the origin group (Former Soviet Union, Turkey, other) and generation status (first and second, 2.5th, and third generations). Controlling for key background characteristics such as grades, it was found that parental knowledge was positively associated with grammar school attendance in three out of five indicators. Overall, however, parental knowledge had only a small impact on group differences, with different patterns emerging: Controlling for knowledge slightly reduced social inequalities, while migration-related inequalities slightly increased. No evidence was found that the effect of knowledge varied by social origin or immigrant background, nor that it depended on the binding nature of teacher recommendations. The results suggested that although parental knowledge was associated with school choice, it did not substantially reduce existing inequalities. We discuss broader implications regarding the potential role of knowledge in shaping educational pathways
MLUH-E-334_1, Aquila heliaca Savigny, 1809, eggshell
No full textInventory No.: MLUH-E-334_1, Object: eggshell, Species: Aquila heliaca Savigny, 1809, Preservation: good preservation, Locality_loc.: Kalmuckensteppe bei Astrachan, Locality today: Kalmykia, Country: RussiaDate: ?, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 171, Identification by: F. Steinheimer, Aquisition: 1909, Aquired from: O. Bamberg, ex Collection: ex. Coll. O. Bamber
Erforschung von Bauteilen aus CuSn10-Biopolymer-Verbundfilament im extrusionsbasierten additiven Fertigungsprozess
No full textDas Metallpulverspritzgießen (Metal Injection Molding, MIM) ist ein Verfahren zur Herstellung
metallischer Bauteile mit komplexer Geometrie, das sich insbesondere für die Massenproduk-
tion eignet. Trotz seiner Vorteile ist das Verfahren mit hohen Kosten und langen Produktions-
zeiten verbunden. In den letzten Jahren hat sich die additive Fertigung (AM), insbesondere die
Materialextrusion (MEX), als Alternative zum Spritzgießen etabliert, um Grünteile herzustellen
und dadurch die Kosten und den Zeitaufwand für Gießformen zu reduzieren. Dabei wird ein
Metall-Polymer-Verbundfilament für den 3D-Druck benötigt. Die thermische Entbinderung, ne-
ben der Lösungsmittel- und der katalytischen Entbinderung, ist ein wichtiger Schritt im Pro-
zess, der sich durch Kosteneffizienz und Umweltfreundlichkeit auszeichnet. Chemische Lö-
sungsmittel und Inertgas werden nicht benötigt. Aktuelle Forschungsergebnisse zeigen je-
doch, dass die Qualität der mittels MEX und thermischer Entbinderung hergestellten Metallteile
aus Verbundfilamenten nach wie vor unzureichend ist. Daher ist eine Optimierung der Eigen-
schaften (Festigkeit, Dichte, Porosität) dieser Bauteile von großer Bedeutung.
In dieser Arbeit wird die Kupferlegierung CuSn10 verwendet, um Metallteile durch MEX her-
zustellen. Ziel der Arbeit ist es, den Herstellungsprozess und die Eigenschaften von CuSn10-
Polymer-Verbundfilamenten in dem AM-Prozess mittels MEX und thermischer Entbinderung
zu optimieren. Dadurch sollen Metallteile kostengünstig und mit einem vereinfachten Verfah-
ren gefertigt werden. Die Optimierung erfolgte sowohl durch eine Prozessoptimierung als auch
durch Materialentwicklung.
Zunächst wurde ein marktverfügbares Filament zur Prozessoptimierung eingesetzt. Hierbei
wurden unterschiedliche Druckparameter, Entbinderungsaufheizraten, Sintertemperaturen so-
wie Haltezeiten untersucht und deren Einfluss auf die Bauteileigenschaften analysiert. Insbe-
sondere der Einfluss von Druck- und Sinterorientierung auf die Fertigungsqualität und Produk-
tionsstabilität wurde umfassend diskutiert. Zusätzlich wurde eine Simulation der Wärmevertei-
lung während der thermischen Entbinderung durchgeführt, um den Prozess zu analysieren
und eine effizientere Entbinderungsmethode durch die Wahl unterschiedlicher Tiegelgrößen
zu identifizieren.
Im Rahmen der Materialentwicklung wurde das Filament eigenständig hergestellt. Dazu wur-
den zunächst PLA-Filamente aus neuem und recyceltem Material extrudiert, deren Eigen-
schaften sowie die der daraus gefertigten Teile untersucht. Anschließend wurde ein hochvo-
lumiges CuSn10-Polymer-Verbundfilament entwickelt. Zwei innovative Bindemittel wurden for-
muliert: eines basierend auf Polylactide (PLA) und Acetyltributylcitrat (ATBC), das andere auf
PLA, Butendiol-Vinylalkohol-Copolymer (BVOH) und ATBC. Mit dem neu entwickelten Fila-
ment konnten Grünteile erfolgreich gedruckt, thermisch entbindert und gesintert werden. Die
Eigenschaften des Filaments sowie der Grün- und Metallteile wurden detailliert charakterisiert. Die Ergebnisse dieser Arbeit zeigen, dass die Prozessparameter die Eigenschaften der her-
gestellten Metallteile erheblich beeinflussen, insbesondere in Bezug auf Dichte, Zugfestigkeit
und Porosität. Durch die gezielte Steuerung von Druckparametern, Aufheizraten während der
Entbinderung, Sintertemperaturen und Haltezeiten konnten eine optimierte Dichte und Zug-
festigkeit erreicht sowie die Porosität deutlich reduziert werden. Druck- und Sinterorientierung
spielten eine zentrale Rolle: Die Kombination aus der Druckorientierung "hochkantig" und der
Sinterorientierung "flach" erwies sich als optimal, um Bauteile ohne Prozessfehler mit verbes-
serter Zugfestigkeit herzustellen. Eine schnelle Aufheizrate während der Entbinderung führte
zu Verformungen und einer Erhöhung der Porosität, während eine verlängerte Entbinderungs-
dauer zwar das Problem minimieren konnte, aber zeitaufwändig war. Dieses Problem ließ sich
jedoch durch den Einsatz größerer Tiegel und die Verwendung von Sand als unterstützendes
Material optimieren.
PLA ist zu 100 % recycelbar, jedoch verschlechtert sich nach der Wiederverwendung die me-
chanischen Eigenschaften. Bei der Herstellung eines Filaments, das aus PLA und hochvolu-
migem Metallpulver besteht, ist der Einsatz von Weichmachern entscheidend, um die Flexibi-
lität des Filaments zu verbessern. Der Anteil des Weichmachers beeinflusst maßgeblich die
Oberflächenrauheit, den Durchmesser, die Flexibilität und die Viskosität des Filaments. Eine
thermische Analyse sowie die Untersuchung der Bindemittelmatrix-Morphologie wurden
durchgeführt, um die Eigenschaften der Bindemittel zu untersuchen. Die Mikrostruktur und die
mechanischen Eigenschaften der hergestellten Metallteile zeigten im Vergleich zu marktver-
fügbaren Filamenten eine verbesserte Zugfestigkeit und eine reduzierte Porosität. Am Beispiel
des Metalls CuSn10 wurde die Erforschung der Metallherstellung durch MEX sowie deren
Machbarkeit eindrucksvoll dargestellt. Die entwickelte Filamentmatrix und das Verfahren kön-
nen zudem auf andere Metalle übertragen werden.Metal Injection Molding (MIM) is a process for manufacturing metallic components with com-
plex geometries, particularly suited for mass production. Despite its advantages, the process
is associated with high costs and long production times. In recent years, Additive Manufactur-
ing (AM), especially Material Extrusion (MEX), has emerged as an alternative to injection mold-
ing for producing green parts, thus reducing the costs and time required for molds. This pro-
cess requires a metal/polymer composite filament for 3D printing. Thermal debinding, along-
side solvent and catalytic debinding, is an important step in the process, characterized by cost
efficiency and environmental friendliness, as chemical solvents and inert gases are not
needed. However, recent research shows that the quality of metal parts made from composite
filaments using MEX and thermal debinding is still insufficient. Therefore, optimizing the prop-
erties (strength, density, porosity) of these components is of great importance.
In this work, the copper alloy CuSn10 is used to produce metal parts through MEX. The goal
of this work is to optimize the manufacturing process and the properties of CuSn10-Polymer
composite filaments in additive manufacturing using MEX and thermal debinding, to enable
cost-effective production of metal parts with a simplified process. Optimization was carried out
through both process optimization and material development.
First, commercially available filament was used for process optimization. Different printing pa-
rameters, debinding heating rates, sintering temperatures, and dwell times were investigated,
and their influence on the part properties was analyzed. In particular, the influence of printing
and sintering orientation on manufacturing quality and production stability was thoroughly dis-
cussed. Additionally, a simulation of heat distribution during thermal debinding was performed
to analyze the process and identify a more efficient debinding method by selecting different
crucible sizes.
As part of the material development, the filament was independently produced. First, PLA fila-
ments made from new and recycled material were extruded, and their properties, as well as
those of the parts produced from them, were examined. Subsequently, a high-volume CuSn10-
Polymer composite filament was developed. Two innovative binders were formulated: one
based on Polylactic Acid (PLA) and Acetyl Tributyl Citrate (ATBC), the other on PLA, Butene-
diol-Vinylalkohol-Copolymer (BVOH), and ATBC. With the newly developed filament, green
parts were successfully printed, thermally debound, and sintered. The properties of the fila-
ment, as well as the green and metal parts, were characterized in detail.
The results of this work show that process parameters significantly influence the properties of
the manufactured metal parts, particularly regarding density, tensile strength, and porosity. By
precisely controlling printing parameters, heating rates during debinding, sintering temperatures, and dwell times, optimized density and tensile strength were achieved, and po-
rosity was significantly reduced. Printing and sintering orientation played a key role: the com-
bination of the "upright" printing orientation and the "flat" sintering orientation proved to be
optimal for producing parts without process errors and with improved tensile strength. A rapid
heating rate during debinding led to distortions and increased porosity, while extended debind-
ing duration minimized this issue but was time-consuming. This problem, however, was opti-
mized by using larger crucibles and sand as a supporting material.
PLA is 100 % recyclable, but its mechanical properties decrease after reuse. When producing
a filament composed of PLA and high-volume metal powder, the use of plasticizers is crucial
to improve the flexibility of the filament. The proportion of the plasticizer significantly affects
the surface roughness, diameter, flexibility, and viscosity of the filament. A thermal analysis
and an investigation of the binder matrix morphology were conducted to examine the proper-
ties of the binders. The microstructure and mechanical properties of the manufactured metal
parts showed improved tensile strength and reduced porosity compared to commercially avail-
able filaments. Using the example of the metal CuSn10, the research on metal production
through MEX and its feasibility was impressively demonstrated. The developed filament matrix
and process can also be applied to other metals.Literaturverzeichnis: Seite 121-13
MLUH-E-265_1, Buteo buteo vulpinus (Gloger, 1833), eggshell
No full textInventory No.: MLUH-E-265_1, Object: eggshell, Species: Buteo buteo vulpinus (Gloger, 1833), Preservation: complete preservation, Locality_loc.: Astrachan, Locality today: Astrakhan, Country: RussiaDate: ?, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 166, Identification by: M. Schönwetter, Aquisition: 1935, Aquired from: Gowland, ex Collection: ex. Coll. Canon O. W. Sancock; ex. Coll. E. C. S. Baker; ex. Coll. C. R. Wood; ex. Coll. Gowlan
Unplanned postoperative angiography after isolated coronary artery bypass grafting : state of the art and future perspective
No full textUnplanned postoperative coronary angiography (uCAG) following isolated coronary artery bypass grafting (CABG) represents a significant clinical challenge, reflecting postoperative myocardial ischemia (PMI) with substantial impact on outcomes. The incidence of uCAG varies from 0.39 to 5.3%, depending on institutional protocols and diagnostic thresholds. Elevated cardiac biomarkers (high-sensitivity troponin and CK-MB), ECG changes, and hemodynamic instability are key indicators guiding uCAG. While associated with increased short-term mortality and morbidity, timely identification and treatment of graft-related complications via uCAG can improve midterm survival. Percutaneous coronary intervention (PCI) often emerges as the preferred therapeutic strategy over redo CABG. Future efforts should focus on refining risk stratification models, expanding the role of non-invasive imaging modalities, and validating early intervention strategies through prospective studies. Establishing standardized criteria for diagnosing and managing PMI remains critical to enhance outcomes and healthcare efficiency
MLUH-E-55_1 , Falco columbarius Linnaeus, 1758, eggshell
No full textInventory No.: MLUH-E-55_1 , Object: eggshell, Species: Falco columbarius Linnaeus, 1758, Preservation: complete preservation, Locality_loc.: Thüringer Wald, Locality today: Thuringia, Country: GermanyCollection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 191, Identification by: M. Schönwetter, Additional Information: Marked with a 17; Label in box says "Lappland" for both egg