Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3

Publications

3 Novel Approach to Design of a Class-EJ Power Amplifier Using High Power Technology

Authors: F. Rahmani, F. Razaghian, A. R. Kashaninia

Abstract:

This article proposes a new method for application in communication circuit systems that increase efficiency, PAE, output power and gain in the circuit. The proposed method is based on a combination of switching class-E and class-J and has been termed class-EJ. This method was investigated using both theory and simulation to confirm ∼72% PAE and output power of >39dBm. The combination and design of the proposed power amplifier accrues gain of over 15dB in the 2.9 to 3.5GHz frequency bandwidth. This circuit was designed using MOSFET and high power transistors. The loadand source-pull method achieved the best input and output networks using lumped elements. The proposed technique was investigated for fundamental and second harmonics having desirable amplitudes for the output signal.

Keywords: Power Amplifier (PA), GaN HEMT, Class-J and Class-E, High Efficiency.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1654
2 Fatty Acids Derivatives and Steroidal Saponins: Abundance in the Resistant Date Palm to Fusarium oxysporum f. sp. albedinis, Causal Agent of Bayoud Disease

Authors: R. Gaceb-Terrak, F. Rahmania

Abstract:

Takerbucht is the only cultivar of date palm known as being resistant to the bayoud disease, caused by Fusarium oxysporum f. sp. albedinis (F.o.a.). In the aim to understand more about the defense mechanisms implied, we realized phytochemical analyses of this cultivar leaflets and roots and this, for the first time, using gas chromatography-mass spectrometry (GC-MS).The examination of our results shows that fifty-four molecules have been detected, fourteen of which are common to leaflets and roots. This study revealed also the organs' richness in derivatives fatty acids: both saturated and unsaturated are represented mainly by methyl esters of Hexadecanoic and 9,12,15-Octadecatrienoic acids. 1-Dodecanethiol, derivative Dodecanoic acid is only present in roots. It’s of great interest to note that the screening revealed the steroidal saponins abundance, among which Yamogenin acetate and Diosgenin, exclusively detected in Takerbucht. They may play an essential role, in the date palm resistance to the bayoud disease.

Keywords: Analysis by GC-MS, leaflets and roots of resistant date palm to F.o.a., derivatives fatty acids, steroidal saponins.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2158
1 The Effect in vitro of Flavonoid Aglycones Extracts from Roots of Date Palm Cultivars on Fusarium oxysporum F. Sp. albedinis

Authors: T. Azouaoui – Ait Kettout, R. Gaceb – Terrak, F. Rahmania

Abstract:

Date production in North Africa is facing a worrying slowdown and a decline because of Fusarium wilt or bayoud date palm (Phoenix dactylifera L., caused by Fusarium oxysporum f. sp. albedinis (F. o. a). The objective of this work is to study the in vitro effect of flavonoid aglycones extracted from the roots of two cultivars of date palm (one sensitive to bayoud (Deglet Nour) and the other resistant (Takerboucht)) on the growth and production fusaric acid of the pathogen. Results show that during the first week of development of F. o. a on potato dextrose liquid medium, the flavonoid aglycones extracts of the susceptible cultivar roots stimulates mycelial growth as well as conidiogenesis of F.o.a, nevertheless it has no effect on the synthesis of fusaric acid. However, the flavonoid aglycones extract of resistant cultivar roots stimulates mycelial growth and decreases both the number of conidia production and fusaric acid. It therefore appears possible that the resistant cultivar aglycones have two types of action: they either inhibit the synthesis of fusaric acid, or they metabolize this toxin into hydrosoluble product, this is called detoxification.

Keywords: Flavonoid Aglycones, date palm, fusaric acid, Fusarium oxysporum f. sp. albedinis.

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1812