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Modification of pomological characteristics and flavour components of fruits and virgin olive oil following wastewater irrigation and soil tillage 下载免费PDF全文
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O Mounkachi E Salmani M Boujnah H Labrim H El Moussaoui M Hamedoun A Benyoussef A El Kenz H Ez-Zahraouy R Masrour E K Hlil 《Bulletin of Materials Science》2014,37(3):563-569
Structural and magnetic properties of Sn0?95Co0?05O2 nanocrystalline and diluted magnetic semiconductors have been investigated. This sample has been synthesized by co-precipitation route. Study of magnetization hysteresis loop measurements infer that the sample of Sn0?95Co0?05O2 nanoparticle shows a well-defined hysteresis loop at 300 K temperature, which reflects its ferromagnetic behaviour. We confirmed the roomtemperature intrinsic ferromagnetic (FM) semiconductors by ab initio calculation, using the theory of the functional of density (DFT) by employing the method of Korringa–Kohn–Rostoker (KKR) as well as coherent potential approximation (CPA, explain the disorder effect) to systems. The ferromagnetic state energy was calculated and compared with the local-moment-disordered (LMD) state energy for local density approximation (LDA) and LDA–SIC approximation. Mechanism of hybridization and interaction between magnetic ions in Sn0?95Co0?05O2 is also investigated. To explain the origin of ferromagnetic behaviour, we give information about total and atoms projected density of state functions. 相似文献
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H. Sehli M. Benabdeslem N. Benslim L. Bechiri H. Ayed A. Djekoun M. Boujnah X. Portier S. Ammar H. Lecoq S. Novack P. Decorse 《JOM Journal of the Minerals, Metals and Materials Society》2014,66(6):985-991
Nanostructured chalcopyrite CuAl0.5Ga0.5Te2 has been prepared by milling a mixture of reactants, copper, aluminum, gallium, and tellurium. The crystal structure, morphology, and composition of the prepared samples have been characterized by means of x-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and transmission electron microscopy (TEM). X-ray diffraction has revealed the presence of the characteristic peaks of the chalcopyrite phase for the CuAl0.5Ga0.5Te2-milled powders. The crystallite size and internal strain have been evaluated by XRD patterns using the Williamson–Hall method. The average particle size decreases as the milling time is prolonged, while the lattice parameters and internal strain increase. The TEM confirmed the formation of CuAl0.5Ga0.5Tee nanoparticles. The bandgap has been found to increase from 1.42 eV up to 1.45 eV as the process time varies, respectively, from 60 min to 360 min. 相似文献
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Mokhtar Guerfel Youssef Ouni Amani Taamalli Dalenda Boujnah Evagellia Stefanoudaki Mokhtar Zarrouk 《European Journal of Lipid Science and Technology》2009,111(9):926-932
The olive oil content in phenolic compounds depends on the variety of the fruit used for its extraction as well as on the predominant climate conditions in the tree cultivation area. Here, we report on the characterization of virgin olive oil samples obtained from fruits of the main Tunisian olive cultivars Chemlali and Chétoui, grown in three different Tunisian locations, Zaghouan (North), Sousse (Center) and Sfax (South). Chétoui olive oil samples obtained from fruits of olive trees cultivated in Zaghouan and Chemlali olive oil samples obtained from fruits of olive trees cultivated in Sousse were found to have a higher mean total phenol content (1004 and 330 mg/kg, respectively). Olive oil samples obtained from fruits of both cultivars had different phenolic profiles and a higher content in 3,4‐DHPEA‐EDA when the olive trees were cultivated in Zaghouan. Both olive cultivars were found to have different responses to environmental conditions. Chétoui olive oil showed decreased oxidative stability when the fruits were obtained from olive trees cultivated in the center of Tunisia (34.8 h) and in Sfax (16.17 h). Furthermore, statistical data showed that the phenolic composition and oxidative stability of Chétoui olive oil varied more by location than those of Chemlali olive oils. 相似文献
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H. Zaari M. Boujnah H. Labrim B. Khalil A. Benyoussef A. El Kenz 《Journal of Superconductivity and Novel Magnetism》2013,26(9):2961-2967
Using ab-initio calculations based on Korringa–Kohn–Rostoker coherent potential approximation (KKR-CPA) method in connection with the local density approximation (LDA), we study theoretically the electronic and magnetic properties of a system based on GaAs material. These properties have been studied, with different point defects in GaAs, which are Gallium interstitials (Gai), Gallium antisites (GaAs), Gallium vacancies (VGa), Arsenic interstitials (Asi) and Arsenic antisites (AsGa), Arsenic vacancies (VAs), and in-doped or codoped system Ga1?x Co x As and Ga1?y?z Co y Fe z As, respectively. This work presents detailed information about total and local density of states at different concentrations of these defects and doped elements; the stability of the ferromagnetic state compared with the spin-glass state has been discussed. The result of electronic properties shows that codoped GaAs material with Fe and Co become ferromagnetic, also doped GaAs with Co or Fe with a defect (hole in Ga) is stable in the ferromagnetic state. The Curie temperature is estimated from the total energy difference between the Disorder Local Moment (DLM) and the (FM) state by using a mapping on the Heisenberg model in mean field approximation. 相似文献
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Dalenda Ben Issa Abdennaceur Kachouri Mounir Samet 《Analog Integrated Circuits and Signal Processing》2011,68(1):9-20
In this paper a new design of Ultra-Wide Band (UWB) generator is presented. This circuit is the most important block in multi-bands
transmitter architecture of UWB communication system. The proposed UWB generator is composed of multi-bands voltage controlled
oscillator (VCO), mixer and rectangular pulse generator which consist of ring oscillator, time delay and AND gate function.
The UWB generator is based on multiplying the rectangular pulse envelope to a continuous sinusoidal wave in order to generate
the UWB signal. This UWB generator circuit produces an output signal which is characterized by the bandwidth of 1600 MHz divided
into three sub-bands of 528 MHz, centered at frequencies of 3.432, 3.96, 4.488 GHz and the limited Power Spectral Density
(PSD) is −41.44 dBm/MHz. The maximum amplitude of UWB signal is 214 mV, the pulse is during of 3 ns and the pulse repetition
period (PRP) is 32 ns. The power consumption is approximately equal to 26 mW at a voltage supply of 2.5 V. This topology is
designed in CMOS 0.35 μm AMS process technology. 相似文献
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Dalenda Jeddi Habib Sidhom Dominique Ghiglione Henri-Paul Lieurade 《Journal of Materials Engineering and Performance》2005,14(1):37-49
The role of retained austenite in the fatigue strength of carburized 14NiCr11 steel was studied by considering two gas-carburizing
treatments leading to two maximum retained austenite fractions of 20 and 40%. These states led to endurance limit improvements
evaluated at 40 and 10%, respectively, compared with the untreated state. These improvements were explained by the evolution
of retained austenite during the cyclic loading using the dispersive x-ray diffraction technique. This reveals that the best
fatigue strength is attributed to the homogeneous transformation of the retained austenite fraction in the treated layer during
the cyclic loading. 相似文献
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O. Mounkachi M. Boujnah H. Labrim M. Hamedoun A. Benyoussef A. El Kenz M. Loulidi B. Belhourma M. Bhihi E. K. Hlil 《Journal of Superconductivity and Novel Magnetism》2012,25(5):1515-1521
Structural and magnetic properties of Zn0.8(Fe0.1, Co0.1)O bulk diluted magnetic semiconductor have been investigated using X-ray diffraction (XRD) and magnetic measurements. TEM (Transmission Electron Microscopy) images confirmed the high crystallinity and grain size of Zn0.8(Fe0.1,Co0.1)O powder, the samples were characterized by energy dispersive spectroscopy (EDS) to confirm the expected stoichiometry. This sample has been synthesized by co-precipitation route. The study of magnetization hysteresis loop measurements infers that the bulk sample of Zn0.8(Fe0.1,Co0.1)O shows a well-defined hysteresis loop at T c (200?K) temperature, which reflects its ferromagnetic behavior. Hydrogenation treatment was used for the control of phase separation. Based on first-principles spin-density functional calculations, using the Korringa?CKohn?CRostoker method (KKR) combined with the coherent potential approximation (CPA), the ferromagnetic state energy was calculated and compared with the local-moment-disordered (LMD) state energy. The mechanism of hybridization and interaction between magnetic ions in Zn0.8(Fe0.1,Co0.1)O is also investigated. 相似文献
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M. L. Ould NE M. Boujnah A. Benyoussef A. El Kenz 《Journal of Superconductivity and Novel Magnetism》2017,30(5):1263-1267
This humble work attempts to study the electronic and electrical conductivity characteristics of AB and AAstacked bilayer graphene (BLG) sheet, by using ab initio calculation. The electronic transport coefficient was calculated by using Boltzmann transport equations implanted in Boltztrap package at various temperatures from 80 to 380 K. First, this study will begin to experiment an interlayer spacing from 3.55 and 3.35 Å respectively for AA and AB-BLG. If the distance between the layers is more than 5.00 Å, the increase or decrease of energy does depend on the interlayer spacing so band gap is equal to zero. The electrical conductivity of AA and AB-BLG is compared to the experimental electrical conductivity of graphene monolayer under increasing spacing between layers to 4.00 Å. Band gap decreases with the increasing space while conductivity increases with increasing space. AA-BLG electrical conductivity shows a value near to the experimental electrical conductivity of graphene ribbon for 4.00 Å at 380 K. Nevertheless, the distance variation does not much affect the electronic and electrical characteristics of AB-BLG. In addition, the increase between the interlayer distances does not influence so much the electrical conductivity. Therefore, increasing the distance between interlayers decreases the electrical conductivity due to the increasing of band gap. 相似文献