Search results for "LMA"

Phenothiazine-based dyes with bilateral extension of π-conjugation for efficient dye-sensitized solar cells

2013

Four novel organic photo-sensitizers based on phenothiazine were designed, synthesized and characterized for efficient dye-sensitized solar cells. Anisole, octyloxybenzene and dodecyloxybenzene were incorporated into the phenothiazine by an Ullmann reaction. An additional octyloxybenzene was incorporated into one dye unit through a Suzuki coupling reaction. The modified phenothiazine moiety acts as an electron donor and cyanoacrylic acid acts as an electron acceptor and anchoring unit. The photophysical, electrochemical and sensitizing characteristics of the new dyes were evaluated. The bis(octyloxybenzene) substituted dye delivered the best performance with its sensitized solar cell displa…

ChemInform Abstract: First Evidence of Proline Acting as a Bifunctional Catalyst in the Baylis-Hillman Reaction Between Alkyl Vinyl Ketones and Aryl …

2008

Proline in the presence of sodium hydrogen carbonate has been found to be an effective catalyst for the Baylis–Hillman reaction between methyl or ethyl vinyl ketone and aryl aldehydes. Screening of several amine catalysts showed that an ionizable carboxylic function directly linked to the secondary amine catalyst plays an important role in the synthesis of the desired product in good yield. The data obtained has allowed us to suggest, for the first time, that proline, sarcosine, pipecolinic acid and homoproline may act as bifunctional catalysts via a bicyclic enaminolactone species as intermediate. Quantum-mechanical calculations (PM3/COSMO and ab initio 3-21G/COSMO) support this mechanism …

Synthesis and Properties of Some Simple Organotitanium Compounds

1986

Before embarking on a detailed discussion of the titanation of carbanions, synthetic and physical organic aspects of several typical organotitanium (IV) compounds shall be surveyed, including thermal stability, aggregation state, X-ray structural data and bond energies. Some of this information is useful in understanding reactivity and selectivity in reactions with organic substrates. Low valent Ti (II) and Ti (III) shall be mentioned only on passing; the interested reader is referred to reviews [1].

Synthese von methyl- und methylenosubstituierten p-Oligophenylenen durch cokondensierende ULLMANN-Reaktion. 12. Mitt.

1963

Es wird ein Syntheseverfahren fur p-Oligophenylene beschrieben, das eine Variante der ULLMANNschen Biarylverknupfungsreaktion darstellt. Dabei wird eine bifunktionelle Jodverbindung mit einem groseren Uberschus an einer monofunktionellen Komponente umgesetzt. Dieses als cokondensierende ULLMANN-Reaktion bezeichnete Syntheseprinzip, das Ausbeuten von 40–50% d. Th. ergibt, wird eingehend erlautert und die Leistungsfahigkeit an zahlreichen Beispielen belegt. Neben einer Reihe von methylsubstituierten p-Oligophenylenen, welche Derivate vom p-Terphenyl bis zum p-Septiphenyl einschliest, werden auch Oligophenylene mit endstandigem oder mittelstandigem Fluorenrest als Strukturelement hergestellt. …

Childhood reproduced: images of childhood represented in children's daily lives in home and day-care settings

2016

ABSTRACTThis study explores images of childhood by analysing children's pictorial representations and accompanying captions. The focus is on how children together with adults represent childhood in the home and daycare settings in a oneweek diary study. The key analytical tool was framing, which is used to highlight what kinds of images are (re)produced and narrated. The frames that emerged were (1) portrayal of the child via cultural products and societal relations, (2) portrayal of the child via individuality, relationships and attachment, (3) the child as a symbol of capabilities, and (4) the child as a learner. While illustrating how childhood was intertwined with consumption, cultural …

Climate Change Mitigation Potentials of Carbon Labels in the Aviation Industry

2018

This chapter discusses the climate change mitigation potentials of carbon labels in the aviation industry. As this study shows, there are significant differences in the environmental performance of individual flights, even when operated on the same route or by the same airline. Selecting one flight over another can significantly reduce the carbon dioxide emissions of a single air passenger. Nevertheless, the currently available measures, such as carbon calculators, are not capable of presenting these differences, leaving air passengers with no means of comparing individual flights. Therefore, the use of carbon labels could be highly beneficial because it would give air passengers the opport…

Intention and practice in environmental governance : Integrated Landscape Approach & REDD

2018

The emission reduction potentials of First Generation Electric Aircraft (FGEA) in Finland

2020

Under the looming climate crisis, aviation needs to find new solutions to cut its greenhouse gas emissions. One pathway towards zero emissions is the use of electric aircraft. While current battery technology will not allow for medium and long-haul flights at full capacity, on short-haul routes First Generation Electric Aircraft (FGEA) could play a significant role in the near future. Current FGEA under development could carry 9–19 passengers on distances of 400–1046 km by 2025. This study focuses on the emissions reduction potentials of FGEA in Finland. It compares the carbon dioxide equivalent (CO2-eq) emissions and real travel times (RTT) from door-to-door of FGEA on 47 routes with exist…

Temperature, phosphorus and species composition will all influence phytoplankton production and content of polyunsaturated fatty acids

2023

Temperature increases driven by climate change are expected to decrease the availability of polyunsaturated fatty acids in lakes worldwide. Nevertheless, a comprehensive understanding of the joint effects of lake trophic status, nutrient dynamics and warming on the availability of these biomolecules is lacking. Here, we conducted a laboratory experiment to study how warming (18–23°C) interacts with phosphorus (0.65–2.58 μM) to affect phytoplankton growth and their production of polyunsaturated fatty acids. We included 10 species belonging to the groups diatoms, golden algae, cyanobacteria, green algae, cryptophytes and dinoflagellates. Our results show that both temperature and phosphorus w…

Basal ice formation in snow cover in Northern Finland between 1948 and 2016

2018

Abstract Basal ice formation in the terrestrial snow cover is a common phenomenon in northern circumpolar areas, one having significant impacts on ecosystems, vegetation, animals and human activities. There is limited knowledge on the spatial and temporal occurrence of basal ice formation because of the sparse observation network and challenges involved in detecting formation events. We present a unique dataset on the annual extent of ice formation events in northern Finland between 1948 and 2016 based on reindeer herders’ descriptions of the cold season in their management reports. In extreme years, basal ice can form over wide geographical extents. In approximately half of the herding dis…