Advanced Laminated Object Manufacturing (LOM) of SiSiC Ceramics

Carbon sheets were used as a starting material for fabrication of SiSiC composites by advanced LOM. This approach consists of three steps: First a preform was fabricated form phenolic resin coated carbon paper with a LOM-device. Second the preform was turned into a carbon preform by pyrolysis in N2-atmosphere. Third pressureless reactive melt infiltration of silicon into the as fabricated carbon preform, which finally yielded a dense SiSiC composite. SEM analysis revealed a microstructure consisting of uniformly dispersed β-SiC grains in a matrix of silicon. The LOM fabricated material exhibited an average four point bending strength and Youngs modulus of 115 MPa and 165 GPa, respectively.Mechanical Engineerin

Perspectives on long-term bee vitality monitoring

Bienen sind essentielle Bestäuber und daher ist ihr Schutz von zentraler Bedeutung für die Sicherung der biologischen Vielfalt und der landwirtschaftlichen Produktion. Innerhalb des Projekts MonViA werden viele Partner zusammen­arbeiten, um wirksame Strategien zur Förderung der biologischen Vielfalt zu entwickeln. Wir präsentieren eine Langzeit-Fallstudie wie sich Klima auf die Leistungsfähigkeit von Honigbienenvölkern auswirkt. Veränderungen des mitteleuropäischen Honigertrags haben wir in Bezug auf die Änderung von Temperatur und Niederschlag modelliert. Eine + 1°C Temperaturänderung steigert den jährlichen Honigertrag um + 0,9 kg pro Volk, während + 100 mm Niederschlag den Ertrag um – 0,4 kg verringert. Basierend auf Klimawandelprognosen im Zeitraum 2020–2050, schätzen wir eine potenzielle Ertragssteigerung von + 0,4 bis + 0,8 kg Honig pro Volk. Wir schließen daraus, dass die Honigbienenpopulation in Deutschland von steigenden Temperaturen profitieren könnte. Weiterhin diskutieren wir, wie die Bienenleistung mit dem Wetter zusammenhängt und wie unsere Analysen durch die Einbeziehung weiterer Daten, mit einer höhe­ren zeitlichen und räumlichen Auflösung, gestärkt werden könnten. Die Einflüsse extremer Wetterbedingungen, imkerlicher Praxis, Krankheitsbelastung, Verfügbarkeit von Nahrungsressourcen, Landnutzung und auch Landschaftsstrukturen sollten im Rahmen des Monitorings der Bienenvitalität miterfasst werden.Bees are essential pollinators and their protection is relevant to secure biodiversity and agricultural production. MonViA-project members and partners collaborate in monitoring projects to develop effective policies to support biodiversity in Germany. In the current case-study, the impact of climate on honey bee population performance was assessed. We modeled year-to-year Central-European honey yield changes and found + 1°C temperature change to stimulate annual honey yield by + 0.9 kg per colony, and + 100 mm precipitation to reduce honey yields – 0.4 kg. In regard to different climate change scenarios for Germany, our modelling suggests a potential + 0.4 to + 0.8 kg honey yield gain per colony in 2050, as compared to 2020. We conclude that the German honey bee population may benefit by rising temperatures. We discuss how bee performance is linked to weather and how our analysis would be strengthened by including more data, with a higher temporal and spatial resolution, i.e., intra-annually and -nationally. Pollinator trend monitoring should be extended with analyses that include e.g., extreme weather conditions, disease loads, availability of floral resource, beekeeping practice, land use and landscape structure

Solid Freeform Fabrication of Ceramic Parts from Filler Loaded Preceramic Polymers

Manufacturing of ceramic parts was achieved by selective laser treatment of a preceramic polymer (polysiloxane) loaded with ceramic filler powder (alumina). Thin layers of polymer/filler powder mixture were sequentially cured with a CO2-laser (λ=10.6 µm) thereby generating the geometrical shape of the part. Subsequently, the cured thermoset part was annealed in nitrogen atmosphere at 600 to 1000 °C to convert the compact into a Si-OC/Al2O3 micro-composite material. Dimensional changes upon pyrolysis (∆l/l0 ≈ 3 %) can be controlled by adjusting the polymer-to-filler ratio and the heat treatment conditions. The new process is called Selective Laser Curing (SLC).Financial support of Fonds der Chemischen Industrie and Deutsche Forschungsgemeinschaft is gratefully acknowledged.Mechanical Engineerin

The Biological Standard of Living in the two Germanies.

Physical stature is used as a proxy for the biological standard of living in the two Germanies before and after unification in an analysis of a cross-sectional sample (1998) of adult heights, as well as among military recruits of the 1990s. West Germans tended to be taller than East Germans throughout the period under consideration. Contrary to official proclamations of a classless society, there were substantial social differences in physical stature in East-Germany. Social differences in height were greater in the East among females, and less among males than in the West. The difficulties experienced by the East-German population after 1961 is evident in the increase in social inequality of physical stature thereafter, as well as in the increasing gap relative to the height of the West-German population. After unification, however, there is a tendency for East-German males, but not of females, to catch up with their West-German counterparts

Особенности налогообложения в розничной торговле

Объектом исследования является: ИП Хорева специализирующееся на розничной торговле изделиями из меха и кожи. Цель работы – анализ деятельности предприятия, определение основных показателей его экономической деятельности, расчет налогов, расчет и анализ налоговой нагрузки предприятия. В процессе исследования проводились: создание теоретической базы для анализа экономической деятельности предприятия, непосредственно анализ экономической деятельности, расчёт и анализ налоговой нагрузки предприятия. В результате исследования выработаны конкретные рекомендации по оптимизации экономической деятельности предприятия.The object of research is: IP Khoreva specializing in the retail sale of fur and leather products. The purpose of the work is the analysis of the enterprise, determining the main indicators of its economic activity, tax calculation, calculation and analysis of the tax burden of the enterprise. In the course of the research, the following was carried out: creation of a theoretical base for analysis of the economic activity of an enterprise, direct analysis of economic activity, calculation and analysis of the tax burden of the enterprise. As a result of the study, specific recommendations were developed to optimize the economic activity of the enterprise

Finite volume corrections to the electromagnetic current of the nucleon

We compute corrections to both the isovector anomalous magnetic moment and the isovector electromagnetic current of the nucleon to $O(p^3)$ in the framework of covariant two-flavor Baryon Chiral Perturbation Theory. We then apply these corrections to lattice data for the anomalous magnetic moment from the LHPC, RBC & UKQCD and QCDSF collaborations

Optical study of the band structure of wurtzite GaP nanowires

We investigated the optical properties of wurtzite (WZ) GaP nanowires by performing photoluminescence (PL) and time-resolved PL measurements in the temperature range from 4 K to 300 K, together with atom probe tomography to identify residual impurities in the nanowires. At low temperature, the WZ GaP luminescence shows donor-acceptor pair emission at 2.115 eV and 2.088 eV, and Burstein-Moss band-filling continuum between 2.180 and 2.253 eV, resulting in a direct band gap above 2.170 eV. Sharp exciton α-β-γ lines are observed at 2.140-2.164-2.252 eV, respectively, showing clear differences in lifetime, presence of phonon replicas, and temperature- dependence. The excitonic nature of those peaks is critically discussed, leading to a direct band gap o

Update of the European Association of Cardiovascular Imaging (EACVI) Core Syllabus for the European Cardiovascular Magnetic Resonance Certification Exam

An updated version of the European Association of Cardiovascular Imaging (EACVI) Core Syllabus for the European Cardiovascular Magnetic Resonance (CMR) Certification Exam is now available online. The syllabus lists key elements of knowledge in CMR. It represents a framework for the development of training curricula and provides expected knowledge-based learning outcomes to the CMR trainees, in particular those intending to demonstrate CMR knowledge in the European CMR exam, a core requirement in the CMR certification process