A Breakthrough toward Long Wavelength Cationic Photopolymerization: Initiating Systems Based on Violanthrone Derivatives and Silyl Radicals

2011 ◽  
Vol 44 (21) ◽  
pp. 8374-8379 ◽  
Author(s):  
Mohamad-Ali Tehfe ◽  
Jacques Lalevée ◽  
Fabrice Morlet-Savary ◽  
Bernadette Graff ◽  
Jean-Pierre Fouassier
Keyword(s):  
Long Wavelength ◽  
Silyl Radicals ◽  
Cationic Photopolymerization

scholarly journals The Applicability of 2-amino-4,6-diphenyl-pyridine-3-carbonitrile Sensors for Monitoring Different Types of Photopolymerization Processes and Acceleration of Cationic and Free-Radical Photopolymerization Under Near UV Light

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1668 ◽  
Author(s):  
Joanna Ortyl ◽  
Paweł Fiedor ◽  
Anna Chachaj-Brekiesz ◽  
Maciej Pilch ◽  
Emilia Hola ◽  
...  
Keyword(s):  
Free Radical ◽  
Fluorescence Probe ◽  
Uv Light ◽  
Molecular Sensors ◽  
Long Wavelength ◽  
Free Radical Photopolymerization ◽  
Cationic Photopolymerization ◽  
Different Types ◽  
Coumarin 1 ◽  
Higher Sensitivity

The performance of a series of 2-amino-4,6-diphenyl-pyridine-3-carbonitrile derivatives as fluorescent molecular sensors for monitoring photopolymerization processes of different monomers by the Fluorescence Probe Technique (FPT) was studied. It has been shown that the new derivatives are characterized by much higher sensitivity than the commercially available 7-diethylamino-4-methylcoumarin (Coumarin 1) and trans-2-(2′,5′-dimethoxyphenyl)ethenyl-2,3,4, 5,6-pentafluorobenzene (25ST) probes. It has been discovered that the 2-amino-4,6-diphenyl-pyridine-3-carbonitrile derivatives accelerate the cationic photopolymerization process initiated with diphenyliodonium photoinitiators at the wavelength where the photoinitiator alone does not work. They are particularly efficient for the photoinitiation of cationic photopolymerization of an epoxide and vinyl monomers. Consequently, the application of the 2-amino-4,6-diphenyl-pyridine-3-carbonitrile derivatives in a dual role: (a) as fluorescent sensors for monitoring the free-radical, thiol-ene and cationic polymerization progress, and (b) as long-wavelength co-initiators for diphenyliodonium salts initiators, is proposed.

Activated Prominences; Mechanisms for Activation and Eruption

1979 ◽  
Vol 44 ◽  
pp. 307-313
Author(s):  
D.S. Spicer
Keyword(s):  
Pressure Gradient ◽  
Density Gradient ◽  
Current Density ◽  
Convective Instability ◽  
Tearing Mode ◽  
Magnetic Shear ◽  
Long Wavelength ◽  
Ideal Mhd ◽  
Gradient Change ◽  
Accelerated Particles

A possible relationship between the hot prominence transition sheath, increased internal turbulent and/or helical motion prior to prominence eruption and the prominence eruption (“disparition brusque”) is discussed. The associated darkening of the filament or brightening of the prominence is interpreted as a change in the prominence’s internal pressure gradient which, if of the correct sign, can lead to short wavelength turbulent convection within the prominence. Associated with such a pressure gradient change may be the alteration of the current density gradient within the prominence. Such a change in the current density gradient may also be due to the relative motion of the neighbouring plages thereby increasing the magnetic shear within the prominence, i.e., steepening the current density gradient. Depending on the magnitude of the current density gradient, i.e., magnetic shear, disruption of the prominence can occur by either a long wavelength ideal MHD helical (“kink”) convective instability and/or a long wavelength resistive helical (“kink”) convective instability (tearing mode). The long wavelength ideal MHD helical instability will lead to helical rotation and thus unwinding due to diamagnetic effects and plasma ejections due to convection. The long wavelength resistive helical instability will lead to both unwinding and plasma ejections, but also to accelerated plasma flow, long wavelength magnetic field filamentation, accelerated particles and long wavelength heating internal to the prominence.

Modern optics of long-wavelength neutrons

1991 ◽  
Vol 161 (11) ◽  
pp. 95 ◽  
Author(s):  
A.I. Frank
Keyword(s):  
Long Wavelength

Slip And Hall Effects On The Flow Of A Hyperbolic Tangent Fluid Through Porous Medium In A Planar Channel With Peristalsis

GIS Business ◽  
2020 ◽  
Vol 15 (1) ◽  
pp. 383-394
Author(s):  
K. Shalini ◽  
K.Rajasekhar
Keyword(s):  
Porous Medium ◽  
Pressure Gradient ◽  
Volume Flow Rate ◽  
Perturbation Technique ◽  
Volume Flow ◽  
Planar Channel ◽  
Hyperbolic Tangent ◽  
Closed Form Solutions ◽  
Long Wavelength ◽  
Hall Effects

In this paper, the effect of Slip and Hall effects on the flow of Hyperbolic tangent fluid through a porous medium in a planar channel with peristalsis under the assumption of long wavelength is investigated. A Closed form solutions are obtained for axial velocity and pressure gradient by employing perturbation technique. The effects of various emerging parameters on the pressure gradient, time averaged volume flow rate and frictional force are discussed with the aid of graphs.

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