Post-2020 climate agreements in the major economies assessed in the light of global models

Integrated assessment models can help in quantifying the implications of international climate agreements and regional climate action. This paper reviews scenario results from model intercomparison projects to explore different possible outcomes of post-2020 climate negotiations, recently announced pledges and their relation to the 2 °C target. We provide key information for all the major economies, such as the year of emission peaking, regional carbon budgets and emissions allowances. We highlight the distributional consequences of climate policies, and discuss the role of carbon markets for financing clean energy investments, and achieving efficiency and equity

Deburring and rounding of sheet metals and functionally relevant edges of parts using laser radiation

The manufacturing of sheet metal parts or component edges often leads to burrs. Due to different requirements regarding the appearance, haptics, tribology et cetera the edges have to be deburred or rounded in a subsequent process. Especially for complex geometries, automated post-processing has been difficult up to now. Laser remelting is one possible solution. It is fully automated and suitable for most 3D geometries. During laser remelting the laser beam is focused on the surface, thus a thin surface layer up to 100 μm is melted. The surface tension in the liquid state is smoothing out the surface and the edge resolidifies rounded. The radius of the rounding is adjustable by the chosen process parameters, especially laser power PL and feed speed vfeed. Furthermore the resulting roughness and the gloss level are controllable via the process parameters. Typical processing speeds are 100 mm edge length per second. First studies with industry partners showed promising results. Laser remelting of push belts for the torque transmission in CVTs lead to an increase of fatigue strength by up to 200% which enables a higher torque

Ohne „Struktursinn“ kein erfolgreiches Mathematiklernen – Ergebnisse einer empirischen Studie zur Bedeutung von Mustern und Strukturen am Schulanfang

Lüken M. Ohne „Struktursinn“ kein erfolgreiches Mathematiklernen – Ergebnisse einer empirischen Studie zur Bedeutung von Mustern und Strukturen am Schulanfang. In: Lindmeier A, Ufer S, eds. Beiträge zum Mathematikunterricht 2010. Vorträge auf der 44. Tagung für Didaktik der Mathematik. Münster: WTM-Verlag; 2010: 573-576

A longitudinal study on avian polyomavirus-specific antibodies in captive Spix's macaws (Cyanopsitta spixii)

Avian polyomavirus (APV) causes a range of disease syndromes in psittacine birds, from acute fatal disease to subclinical infections, depending on age, species, and other unidentified risk factors. To determine the prevalence of APV-specific antibodies in a captive population of Spix’s macaws (Cyanopsitta spixii) in Quatar, 54 birds were tested by blocking enzyme-linked immunosorbent assay. A prevalence of 48.1% for APV antibodies, which indicates viral exposure, was found. Of 36 Spix’s macaws that were serially tested over a period of 4 years, 50.0% were consistently positive, 36.1% were consistently negative, 5.5% had permanently declining antibody levels, and 2.8% showed variable results. By using polymerase chain reaction testing on whole blood samples, an apparent viremia was detected in 1 of 44 birds (2.3%), although contamination provides a likely explanation for this isolated positive result in a hand-reared chick. The white blood cell count was significantly higher in antibody-positive birds compared with antibody-negative birds (P<0.05). Because antibody-positive and antibodynegative birds were housed together without a change in their respective antibody status, transmission of APV within the adult breeding population appeared to be a rare event

Junge Kinder beschreiben Musterfolgen

Tiedemann K, Lüken M. Junge Kinder beschreiben Musterfolgen. In: Siller H-S, Weigel W, Wörler JF, eds. Beiträge zum Mathematikunterricht 2020. 2020: 1261-1265