1,720,994 research outputs found
Photochemie im sonnenlicht – zurück auf die Dächer! [Photochemistry in sunlight - back to the roof!]
No full textDas systematische lnteresse an chemischen Reaktionen mit Licht begann im 19. Jahrhundert auf den Dachern der chemischen Institute. Reaktionslosungen wurden in dickwandige Glasrohre eingeschmolzen und fUr langere Zeit dem Sonnenlicht ausgesetzt. Auch heute noch werden vie le Solarversuche mit dem "Kolben in der Sonne" durchgeführt. Dank der Entwicklung von modernen Solarreaktoren lassen sich Versuche heutzutage aber auch in technisch interessanten Maβsätben umsetzen.
[Sunlight can be used effectively for the synthesis of chemicals. In most cases, products are isolated in higher purity and yields due to the absence of destructive UV-light. Whereas mirror systems achieve faster conversions, the simple CPC-system showed the most robust performance under a variety of weather conditions. Solar chemistry is especially interesting for the synthesis of fine chemicals, which are typically required in small quantities.
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Kombination aus photochemischer synthese und mikroverfahrenstechnik – photochemie im Durchfluss [Combination of photochemical synthesis and microprocess engineering - photochemistry in continuous flow]
No full textChemische Synthesechemie wird traditionell in Rundkolben oder Ruhrkesseln betrieben. In den letzten Jahren hat sich aber die Durchfluss-Chemie als potenzielle Alternative entwickelt. Transparente Mikroreaktoren sind insbesondere interessant fürdie synthetische Photochemie. lhre kleinen Durchmesser von typischerweise 0.05 bis 1 Millimeter erlauben eine optimale Durchdringung der Reaktionslbsung mit Licht. Der Durchflussmodus minimiert gleichzeitig die Abbaureaktionen lichtempfindlicher Produkte.
[Continuous flow photochemistry elegantly combines the advantages of microprocess engineering with continuous flow operation. The technology allows for photochemical synthesis on micro- to multigram-scales. The realization of the elegant Haraeus process demonstrates the renewed interest of the chemical industry in synthetic photochemistry. Specialized modules with optimized photoreactor units and light sources are now commercially available. It is hoped that continuous flow photochemistry will find widespread applications in research and development as well as in the production of pharmaceuticals and agrochemicals.
Erstens kommt es anders, als man zweitens denkt : mit an Sicherheit grenzender Wahrscheinlichkeit – logisches Denken und Zufall
No full textRezension zu: Hans-Hermann Dubben und Hans-Peter Beck-Bornholdt : Mit an Wahrscheinlichkeit grenzender Sicherheit : logisches Denken und Zufall. rororo science. Rowohlt Taschenbuch Verlag, Reinbek 2005, 2. Auflage Januar 2006, ISBN 3-499-61902-4, 219 Seiten, 8,90 Euro
Ein Unternehmen aus universitären Wurzeln : BioSpring - Erfolgsgeschichte einer im Frühling 1997 gegründeten Biotech-Firma
No full textPatentierte akademische Spürnase : Frankfurter Physiker entwickeln neuartige Sensoren für wässrige Systeme – Probelauf mit Bieranalyse
No full textAus Zwei wird Eins : Neubau des Max-Planck-Instituts für Biophysik auf dem Campus Riedberg
No full text
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
- …
