Search results for " Plastics"
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Umwandlungserscheinungen in amorphen Hochpolymeren beim tempern unterhalb der Glastemperatur
1968
Es wird die zeitliche Anderung der mechanischen Eigenschaften von amorphem PC, PET und PMMA beim isothermen Tempern unterhalb der Glastemperatur untersucht. Dabei ergab sich, das von der Glastemperatur abgeschrecktes Material beim Tempern ein stufenweises Ansteigen des Schubmoduls zeigt, das von einer Abnahme der Dampfung begleitet ist. Kurzzeitiges Uberschreiten der Glastemperatur mit nachfolgendem Abschrecken macht die durch das Tempern bewirkten Anderungen ruckgangig. Die Beobachtungen werden als Platzwechsel von Kettensegmenten im Sinne einer Ausbildung von lokal begrenzten Bereichen hoherer Dichte gedeutet, die sich beim Uberschreiten der Glastemperatur wieder auflosen.
Die morphologische Struktur von Copolymeren des Äthylens abhängig von den Gegebenheiten des Molekülbaues
1966
Elektronenmikroskopische Aufnahmen an Copolymeren des Athylens belegen im Beispiel losungskristallisierter Proben in Ubereinstimmung mit einfachen theoretischen Uberlegungen, das das morphologische Erscheinungsbild mit wachsender Unregelmasigkeit im Molekulbau aus einem lamellar-regelmasigen Typ in unregelmasige flussigkeitsahnliche Strukturen ubergeht. Fur schmelzkristallisierte Proben mus man ahnliche Gesetzmasigkeiten erwarten, wenn der Kristallanteil sowie die Verteilung der Kristalle einschlieslich deren Grosenstatistik sich im morphologischen Erscheinungsbild ausdrucken sollen. Man findet an Oberflachen schmelzkristallisierter Filme jedoch nur einen sehr losen Zusammenhang mit den gen…
Freemasonry and Education in Contemporary Spain. Between Tolerance and Dogmatism
2017
Resumen:En este trabajo vamos a centrarnos casi en exclusiva en las iniciativas planteadas por diversas entidades masónicas, ya sean potencias, logias regionales o talleres, más que en personas exponiendo solamente algunas de las experiencias más relevantes y que ejemplifican mejor las intervenciones y actuaciones de la masonería española en relación con los enfoques descritos. La visibilidad que han alcanzado otras parcelas e interpretaciones del comportamiento, de los masones en particular y de las iniciativas de la masonería como institución, no nos deben ocultar la faceta desarrollada en torno a la educación. ¿Qué importancia tuvo el proceso formativo llevado a cabo en los talleres masó…
Semblanza de José Antonio Ayala Pérez
2014
José Antonio Ayala Pérez (1935-2014).
Numerical simulation of transcatheter mitral valve replacement: The dynamic implication of LVOT obstruction in the valve-in-ring case.
2022
Transcatheter mitral valve replacement (TMVR) has been used for “off-label” treatment when annuloplasty band ring for mitral repair fails. However, the complex anatomy and function of the mitral valve may lead to fatal complications as a result of the left ventricular outflow tract (LVOT) obstruction in TMVR. We report the structural and hemodynamic response of LVOT obstruction resulting from TMVR with the Edwards SAPIEN 3 Ultra (S3) device. We modified the original Living Heart Human Model (LHHM) to account for a failed mitral valve with an annuloplasty band ring and simulated the cardiac beating condition in the setting of S3 device implantation. Findings demonstrated a high dynamic behav…
Heat-Resistant Fully Bio-Based Nanocomposite Blends Based on Poly(lactic acid)
2013
Poly(lactic acid) (PLA) is melt mixed with polyamide 11 (PA11) to obtain a heat-resistant fully bio-based blend with PLA as the dominant component. The goal is achieved by adding small amounts of organoclay (OMMT), which is used to manipulate the blend microstructure. The selective positioning of the OMMT inside the PA11 and at the PLA/PA11 interface turns the blend morphology from drop/matrix into co-continuous at high PLA content (70 wt%). The OMMT-rich PA11 framework that interpenetrates the major PLA phase effectively contributes to bear stresses, and the nanocomposite blend keeps its structural integrity up to ≈160 °C, i.e., about 100 °C above the PLA glass transition.
Urban-rural Interactions in Latvia
2010
Policies and plans for rural areas tend to start by assuming that they are separate and distinctive from urban areas, and that this distinctiveness is more important than any of their other characteristics. Laila Kule argues that this introduces an unwelcome hierarchy in regional development priorities, and shows how Latvia has attempted to build on connectivity rather than difference in urban-rural development.
Is large-scale rapid CoV-2 testing a substitute for lockdowns?
2021
Background Various forms of contact restrictions have been adopted in response to the Covid-19 pandemic. Around February 2021, rapid testing appeared as a new policy instrument. Some claim it may serve as a substitute for contact restrictions. We study the strength of this argument by evaluating the effects of a unique policy experiment: In March and April 2021, the city of Tübingen set up a testing scheme while relaxing contact restrictions. Methods We compare case rates in Tübingen county to an appropriately identified control unit. We employ the synthetic control method. We base interpretations of our findings on an extended SEIR model. Findings The experiment led to an increase in the …
B Cell Expansion Hinders the Stroma-Epithelium Regenerative Crosstalk During Mucosal Healing
2021
Little is known about the pro-resolution role of immune cells recruited to damaged tissue. Using an experimental model of intestinal epithelial damage and repair, we identified B cells as the dominant cell type in the healing colon. Single-cell RNA-sequencing (scRNAseq) revealed the expansion of an IFN-induced B cell subset during experimental mucosal healing which was associated with colitis severity. In line with this, B cell depletion during mucosal healing resulted in accelerated recovery upon injury, which was associated with enhanced expression of tissue remodeling genes. scRNA-seq from the epithelial and stromal compartment confirmed that lack of B cells during mucosal healing alters…
An International Comparison of Skills, Traits and Job Mobility
2019
Making use of an international survey that directly assesses the cognitive skills of the adult population, I document systematic differences in the effect of skills on job mobility across the 37 countries in the sample. While economic growth is associated with relatively higher job mobility among skilled workers, the prevalence of information and communication technology (ICT) in the workplace is associated with relatively lower job mobility. The documented patterns are in line with Schumpeterian growth models of creative destruction in which skilled workers transition to jobs with advanced technologies more easily.