High Frequency (27.12 MHz) Activation of the Radical Curing of Unsaturated Polyesters in Styrene Solution

MRS Proceedings ◽

10.1557/proc-430-593 ◽

1996 ◽

Vol 430 ◽

Cited By ~ 1

Author(s):

P. Alazard ◽

A. Gourdenne

Keyword(s):

Transition Temperature ◽

Benzoyl Peroxide ◽

High Frequency ◽

Steel Plates ◽

Crosslinking Reaction ◽

High Frequencies ◽

Unsaturated Polyesters ◽

Radical Initiator ◽

Electrical Voltage

AbstractThe crosslinking reaction of a divinylester resin of epoxy-acrylic type in styrene solution is activated by high frequencies at 27.12 MHz. The samples to be cured are positionned betweeen two parallel steel plates used as electrodes and an electrical voltage is applied. A parametrical study is described, where the applied electrical voltage, or power, and the concentration of benzoyl peroxide, which is the radical initiator, are taken into account. The optimization of the electromagnetic curing is performed through the determination of the glassy transition temperature of the final products.

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Rapid determination of water in benzoyl peroxide by high frequency method

BUNSEKI KAGAKU ◽

10.2116/bunsekikagaku.22.1440 ◽

1973 ◽

Vol 22 (11) ◽

pp. 1440-1445

Author(s):

Yuichi KAMURA ◽

Sabro MIZUTANI ◽

Keiko TOMIHISA ◽

Masakazu SUGIYAMA

Keyword(s):

Benzoyl Peroxide ◽

High Frequency ◽

Rapid Determination ◽

Frequency Method

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HIGH-FREQUENCY DIFFRACTION BY A SPHERE

Canadian Journal of Physics ◽

10.1139/p61-175 ◽

1961 ◽

Vol 39 (10) ◽

pp. 1486-1494

Author(s):

C. L. Tang

Keyword(s):

Plane Wave ◽

High Frequency ◽

Rotational Symmetry ◽

Asymptotic Series ◽

Three Dimensional ◽

Shadow Region ◽

High Frequencies ◽

Present Procedure ◽

Dimensional Object

A systematic procedure is given for the determination of the asymptotic series directly from the Helmholtz equation and the boundary conditions for the field in the shadow region of a sphere illuminated by a plane wave at high frequencies. The first two terms in the series for the shadow region, including the regions near the axial caustic and the boundary layer near the surface of the sphere, are explicitly evaluated. The present procedure can be generalized to any smooth convex three-dimensional object with a rotational symmetry, illuminated by a plane wave in the direction of the axis of rotational symmetry.

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Detection of clear sky instants from high frequencies pyranometric measurements of global horizontal irradiance

E3S Web of Conferences ◽

10.1051/e3sconf/202122901008 ◽

2021 ◽

Vol 229 ◽

pp. 01008

Author(s):

Omaima El Alani ◽

Hicham Ghennioui ◽

Abdellatif Ghennioui ◽

Fatima-ezzahra Dahr

Keyword(s):

High Frequency ◽

Resource Assessment ◽

High Frequencies ◽

Energy Field ◽

Clear Sky ◽

Stable Conditions ◽

Soil Measurements ◽

Solar Resource

Solar resource assessment by clear sky models is of great importance in the solar energy field: verifying the performance of photovoltaic systems during stable conditions, clouds effects evaluation, the determination of geographical areas where irradiation is more uncertain and the preparation of forecasts with sky cameras. But before using these models they must be validated against high performances soil measurements. Since there is no radiometric sensor that measures clear-sky radiation, then historical clear-sky time periods must be identified only from long-term allsky irradiation records. The contribution of this study is to exploit the ground measurements, analyze them and retrieve the information they contain concerning the clear sky instants. The study will be performed by comparing the clear sky instants identified by an algorithm proposed by Reno and Hansen with a physical clear sky model. This comparison is made using high frequency global horizontal irradiation (GHI) data from high performances meteorological station installed at Benguerir in Morocco.

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Detection of clear sky instants from high frequencies pyranometric measurements of global horizontal irradiance

E3S Web of Conferences ◽

10.1051/e3sconf/202129701028 ◽

2021 ◽

Vol 297 ◽

pp. 01028

Author(s):

Omaima El Alani ◽

Hicham Ghennioui ◽

Abdellatif Ghennioui ◽

Fatima-ezzahra Dahr

Keyword(s):

High Frequency ◽

Resource Assessment ◽

High Frequencies ◽

Energy Field ◽

Clear Sky ◽

Stable Conditions ◽

Soil Measurements ◽

Solar Resource

Solar resource assessment by clear sky models is of great importance in the solar energy field: verifying the performance of photovoltaic systems during stable conditions, clouds effects evaluation, the determination of geographical areas where irradiation is more uncertain and the preparation of forecasts with sky cameras. But before using these models they must be validated against high performances soil measurements. Since there is no radiometric sensor that measures clear-sky radiation, then historical clear-sky time periods must be identified only from long-term all-sky irradiation records. The contribution of this study is to exploit the ground measurements, analyze them and retrieve the information they contain concerning the clear sky instants. The study will be performed by comparing the clear sky instants identified by an algorithm proposed by Reno and Hansen with a physical clear sky model. This comparison is made using high frequency global horizontal irradiation (GHI) data from high performances meteorological station installed at Benguerir in Morocco.

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