Search results for "Effects"

Influence of Reactant Polarity on the Course of the Inverse-Electron-Demand Diels−Alder Reaction. A DFT Study of Regio- and Stereoselectivity, Presen…

1999

The molecular mechanisms for the inverse-electron-demand Diels−Alder reactions between nitroethene and three substituted ethenes (propene, methyl vinyl ether, and dimethylvinylamine) to give the corresponding nitroso cycloadducts have been characterized with density functional theory methods using the B3LYP/6-31G* calculational level. On the basis of stability arguments and molecular orbital analysis relative rates, regioselectivity, and stereoselectivity, the presence of Lewis acid catalyst modeled by the BH3 system and the inclusion of solvent effects as a function of the nature of substituent in the dienophile fragment are analyzed and discussed. The ortho attack mode presents transition…

ChemInform Abstract: Influence of Reactant Polarity on the Course of the Inverse-Electron-Demand Diels-Alder Reaction. A DFT Study of Regio- and Ster…

2010

The molecular mechanisms for the inverse-electron-demand Diels−Alder reactions between nitroethene and three substituted ethenes (propene, methyl vinyl ether, and dimethylvinylamine) to give the corresponding nitroso cycloadducts have been characterized with density functional theory methods using the B3LYP/6-31G* calculational level. On the basis of stability arguments and molecular orbital analysis relative rates, regioselectivity, and stereoselectivity, the presence of Lewis acid catalyst modeled by the BH3 system and the inclusion of solvent effects as a function of the nature of substituent in the dienophile fragment are analyzed and discussed. The ortho attack mode presents transition…

C-H Bond Arylation of Pyrazoles at the β-Position: General Conditions and Computational Elucidation for a High Regioselectivity

2021

International audience; Direct arylation of most five-membered ring heterocycles are generally easily accessible and strongly favored at the α-position using classical palladium-catalysis. Conversely, regioselective functionalization of such heterocycles at the concurrent β-position remains currently very challenging. Herein, we report general conditions for regioselective direct arylation at the β-position of pyrazoles, while C-H α-position is free. By using aryl bromides as the aryl source and a judicious choice of solvent, the arylation reaction of variously N-substituted pyrazoles simply proceeds via β-C-H bond functionalization. The β-regioselectivity is promoted by a ligand-free palla…

Interactive effects of boron and salinity on greenhouse tomato grown in closed soilless system.

2012

On the trail of local welfare innovations in rural Finland

2019

Final Draft In Finland, the rural areas have been most affected by the developments threatening the survival of the welfare state as well as by conflicting efforts to save it. However, there are rural communities that have—as a response to the mainstream policy emphasizing economic efficiency and individual responsibility—developed innovative solutions to secure their welfare. Based on a case study focusing on two of such communities, these local welfare innovations are a result from a combination of external causes and local resources including the sense of community and a diverse enough community structure. The authors argue that in the context of welfare policy, the promotion of local we…

Community Resilience to Cyclone Disasters in Coastal Bangladesh

2016

Bangladesh is one of the poorest and most disaster-prone countries in the world. To address both problems simultaneously, sustainable livelihoods (SL) could be better connected with disaster risk reduction (DRR). For this purpose, one initiative implemented in Bangladesh is called the Vulnerability to Resilience (V2R) programme which ran from 2013 to 2016. This programme was primarily initiated and funded by the British Red Cross in a consortium with the Swedish Red Cross and the German Red Cross. This article presents the first evaluation of the V2R programme with three objectives. The first objective was to measure whether the selected communities have achieved community resilience charac…

A Non-Local Mode-I Cohesive Model for Ascending Thoracic Aorta Dissections (ATAD)

2018

This paper presents a non-local interface mechanical model to describe aortic dissection. In this regard, the mode-I debonding problem based on a cohesive zone modeling is endowed with non-local terms to include long-range interactions that are present in multi-layered biological tissue. Such non-local effects are related to the collagen fibers that transmit forces between non-adjacent elements. Numerical simulations are provided with different values of the non-local parameters in order to show the effect of the non-locality during the debonding processes.

"Having a drink in a bar": An immersive approach to explore the effects of context on drink choice

2013

UT: 000315557500004; International audience; This paper aims to evaluate the effect of context on food choices. Two studies are presented to test the potential of an immersive approach to help understanding contextual influences on drink choices. To generate contextual effects, two bar-like environments based on the idea of "having a drink in a bar" were created: one with wood furniture and one with blue furniture. In both immersive bars, clips with visual and music stimuli were projected on a wall to change the overall warmth of the ambience. In the first study, five different clips were projected. Participants in the immersive bars had to choose a drink within a large range of drinks for …

Chiroptical Phenomena in Reverse Micelles: The Case of (1R,2S)- Dodecyl (2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium Bromide (DMEB)

2014

(1R,2S)-Dodecyl(2-hydroxy-1-methyl-2-phenylethyl)dimethylammonium bromide (DMEB) aggregates dispersed in carbon tetrachloride have been investigated by Fourier transform infrared (FT-IR), vibrational circular dichroism (VCD) and 1H nuclear magnetic resonance (NMR) spectroscopy at various surfactant concentration and water-to-surfactant molar ratio. Experimental data indicate that, even at the lowest investigated concentration and in absence of added water, DMEBmolecules associate in supramolecular assemblies. At higherDMEBconcentration the aggregates can confine watermolecules,making it plausible to think thatDMEB form reverse micelles and that watermolecules are quite uniformly distributed…

1H-NMR and FT-IR study of the state of melatonin confined in membrane models: location and interactions of melatonin in water free lecithin and AOT r…

2004

The state of melatonin confined either in dry lecithin or bis(2-ethylhexyl) sulfosuccinate sodium salt (AOT) reversed micelles has been investigated by H-1-NMR and FT-IR spectroscopies as a function of the melatonin to surfactant molar ratio (R). The analysis of experimental results leads to hypothesize that, independently of R and the surfactant nature and as a consequence of anisotropic melatonin/surfactant interactions, melatonin is totally solubilized in reversed micelles and mainly located by opportune orientation in the nanodomain constituted by the surfactant head groups. The absence of significant spectral changes related to the protons linked to the first carbon atoms of surfactant…