196,072 research outputs found
„Ich sehe was, was Du nicht siehst" - eine multiperspektivische Zusammenschau auf den Fall Faruk Zadek
No full textKöttig M, Gahleitner SB, Kunz T, Thiessen B, Völter B. „Ich sehe was, was Du nicht siehst" - eine multiperspektivische Zusammenschau auf den Fall Faruk Zadek. In: Köttig M, Borrmann S, Effinger H, Gahleitner SB, Kraus B, Stövesand S, eds. Soziale Wirklichkeiten in der Sozialen Arbeit : wahrnehmen, analysieren, intervenieren. Buchreihe Theorie, Forschung und Praxis der sozialen Arbeit. Vol 9. Opladen: Budrich; 2014: 33-48
Influence of post-processing ageing on mechanical strength of injection molded polypropylene
No full textDie Herstellung der Adressat_innen durch pädagogische Beobachtung. Theoretische und empirische Hinweise zur Gegenstandskonstituierung
No full textSchmidt F, Schulz M. Die Herstellung der Adressat_innen durch pädagogische Beobachtung. Theoretische und empirische Hinweise zur Gegenstandskonstituierung. In: Köttig M, Bormann S, Effinger H, Gahleitner SB, Kraus B, Stövesand S, eds. Soziale Wirklichkeiten in der Sozialen Arbeit: Wahrnehmen - analysieren - intervenieren. Opladen: Barbara Budrich; 2014: 209-218
Real-time structural characterization of isotactic polypropylene during cast film extrusion
No full textUnderstanding the crystallization behavior of semi-crystalline polymers during processing is key to achieve the desired material performances. Isotactic polypropylene characteristics are highly tunable and easy to adjust by changing the processing conditions thanks to its structural versatility and polymorphic behavior. Hereby, we performed for the first time ever a challenging real-time X-ray characterization of isotactic polypropylene during the cast film extrusion process by interfacing a compact cast film extruder machine with a synchrotron line. We report data of excellent quality recorded from the contact point between the just extruded polymer melt and the water-refrigerated cooling roll further down to the cooling roll line by using a grazing incidence scattering geometry. The explored cooling roll temperatures (from 70 degrees C to 15 degrees C) allowed to produce iPP films with defined structural composition, from alpha to mesophase. Evolution of the phase crystallinity as a function of the contact time between the polymer melt and the cooling roll clearly shows the presence of three crystallization zones: 1) an amorphous zone, 2) a frostline zone and lastly 3) a high-crystallinity zone. In the end, the experimental data have been matched with simulated data using a simple crystallization kinetics model, finding a good agreement in terms of crystalline development over the investigated time scale. As a closing remark, we hope that our effort will spark new interest in the real-time characterization of semicrystalline materials and that will ultimately be utilized as a starting point to optimize and expand the characterization of these extremely important materials
Personzentriert sein – die Zukunft liegt nicht in der Vergangenheit. Anmerkungen zum Aufsatz „Personzentriert sein – Sieben Herausforderungen für die Zukunft" von M. Behr, J. Finke und S. Gahleitner in PERSON 1/2016
No full textDer Beitrag ist eine Replik auf den nach Anpassung an den Mainstream plädierenden Aufsatz von Behr et al. Es wird gezeigt, dass viele der dort angeführten „Herausforderungen“ mit dem personzentrierten Paradigmenwechsel inkompatibel sind.Being person-centred — the future does not lie in the past. Remarks to „Being person-centered — Seven challenges for the future“ by M. Behr, J. Finke and S. Gahleitner in PERSON 1/2016. The piece is a riposte to Behr’s et al. paper that reads as a plea for adaption to the mainstream. It indicates that many of the „challenges“ enumerated are incompatible with the person-centred paradigm change
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
Continuous Cooling Curve Diagrams of Isotactic-Polypropylene/Polyethylene Blends: Mutual Nucleating Effects under Fast Cooling Conditions
No full textCrystallization kinetics under processing-relevant cooling conditions of polyethylene/isotactic-polypropylene (PE/PP) blends, with compositions similar to real recycled blends, was investigated through an in situ temperature monitoring technique. Continuous Cooling Curve (CCC) diagrams in a large crystallization temperature range were obtained for the two phases, thanks to a new apparatus allowing fast quenching of polymer samples. Using this technique, we found an "inversion point" in the crystallization order of the two polymers, which arises from the difference in crystallization rates between PP and PE with an increasing cooling rate. The order of crystallization of the two polymers at low cooling rates, that is, before the inversion point, can be tuned by employing non-nucleated or nucleated PP. In particular, non-nucleated PP crystallizes after PE above 0.5 degrees C/s, while nucleated PP solidifies before PE until 80 degrees C/s. Interestingly, mutual nucleating effects, previously shown only for ideal systems such as thin-layered films, were found at the interface between the phases, in correlation with the inversion point. During cooling, the phase which crystallizes first can enhance the onset of crystallization of the second lower crystallizing phase through nucleation at the interface. Ex situ morphological and wide-angle X-ray diffraction experiments confirmed the validity of the results shown by CCC diagrams. Our approach to characterize semicrystalline polymer blends with CCC diagrams facilitates tailoring their properties at cooling rates relevant for polymer processing. Moreover, the importance of knowing and controlling the type of components in blends obtained from recycling is demonstrated, given the variety of crystallization behaviors attainable
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
A method for studying nucleating additives in high-density polyethylene via crystallization of micro-droplets in immiscible blends
No full textTypically, the study of additives with nucleating ability towards high-density polyethylene (HDPE) is challenging, because of the exceedingly high intrinsic nucleation density of this polymer, which prevents the detection of mild nucleation effects with standard calorimetric methods. Here we propose a novel method to tackle this issue by making use of the fractionated crystallization, observed when blending HDPE with polystyrene (PS). In this system, a small amount of HDPE is dispersed into droplets of around 1 μm size in the amorphous matrix and, due to the presence of droplets ensembles free of nucleating heterogeneity, the achievable undercooling is greatly enlarged with respect to bulk HDPE. As such, it is found that various potentially nucleating additives affect the fractionated crystallization behavior of the blend, forming populations of droplets which crystallize at distinctly higher temperatures with respect to that of neat HDPE/PS. On the contrary, bulk additivated HDPEs do not show meaningful differences in their peak crystallization temperatures. The method was applied to the technological problem of shrinkage and warpage in injection moulded coloured HDPEs, revealing that the critical behavior of a particular coloured masterbatch could be clearly associated with its higher nucleating efficiency with respect to a “non-critical” masterbatch. Moreover, the calculation of the fraction of crystallization enthalpy in selected temperature ranges allowed to determine in a semi-quantitative way the nucleation efficiency of several additives. Thus, the proposed fractionated crystallization approach proved to be successful in the notoriously difficult task of assessing different HDPE nucleating additives
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