In this present paper, an experimental study of some plasma characteristics in dielectric barrier discharge (DBD) system using several variables, such as different frequencies and using two different electrodes metals(aluminium (Al) and copper (Cu)), is represented. The discharge plasma was produced by an AC power supply source of 6 and 7 kHz frequencies for the nitrogen gas spectrum and for two different electrodes metals(Al and Cu). Optical emission spectrometer was used to study plasma properties (such as electron temperature ( ), electron number density ( ), Debye length ( ), and plasma frequency ( )). In addition, images were analysed for the plasma emission intensity at atmospheric air pressure.
Аннотация
В статье считается национально-культурная специфика и языковое изменчивость выражения заключений в художественном тексте. В настоящее время в изучении художественного текста существует множество взаимодополняющих подходов и концепций, которые способствуют лучшему пониманию его языковых и культурных аспектов. Художественный текст как «воспроизведение» и от
... Show MoreIn this work, HgBa2CaCu2-xSbxO8+δ compounds with (x = 0.2, 0.4, 0.6 and 0.8) have been prepared by the solid-state reaction method. Structural, morphological, and electrical properties were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. Using the 4-probe technique to study the effect of antimony-substitution for Copper on the electrical properties of HgBa2CaCu2-xSbxO8+δ (Hg-1212) phase was investigated by measuring the resistivity as a function of temperature. Results indicate that the addition of antimony (Sb) increases the volume fraction of the phase and changes the superconducting transition temperature Tc of the superconductor to a normal state. The dielectric loss factor and ac
... Show Moreدُرِست العوامل المؤثرة في عدد ساعات تجهيز الكهرباء في مدينة بغداد، وتكونت عينة الدراسة من (365) مشاهدة يومية لعام 2018، وتمثلت بستة متغيرات استعملت في الدراسة. كان الهدف الرئيس هو دراسة العلاقة بين هذه المتغيرات، وتقدير تأثيرات المتغيرات التنبؤية في المتغير التابع (عدد ساعات تجهيز الكهرباء في مدينة بغداد). ولتحقيق ذلك استعملت نمذجة المعادلات الهيكلية/ تحليل المسار وبرنامج AMOS
... Show MoreIn the present study, nanoporous material type MCM-41 was prepared by the sol-gel technique and was used as a carrier for prednisolone (PRD) drug delivery. The structural properties of mesoporous were fully characterized by X-ray diffraction (XRD), N2 adsorption /desorption and Fourier-transform infrared (FTIR). The mass transfer in term of adsorption process (loading) and desorption process (releasing) properties were investigated. The maximum drug loading efficiency was equal to 38% and 47.5% at different concentrations. The PRD released was prudently studied in water media of pH 6.8 simulated body fluid (SBF) in according to "United State Pharmacopeia (USP38)". The results proved that the release of prednisolone from MCM-41
... Show MoreThe present study attempts to shed light on some biological aspects and characteristics of Piaractus brachypomus, including some biometrics, phenotypic and feeding pattern that characterizes this species. Besides, the study touches upon the body shape and the Otolith. These fish species have recently been seen frozen in the Iraqi local market. The standard length of fish specimens in this study reach 26.55cm it exceeded the specimens of Pacu fish collected from other studies from other countries, As well the specimens weight was 632gm it exceeded other studies mentioned in this manuscript. As the irregularity in the distribution of teeth rows, especially in the lower jaw was clear in our specimens. The average weight of some skull b
... Show MoreThe effect of micro-and nano silica particles (silica SiO2 (100 μm), Fused silica (12nm)) on some mechanical properties of epoxy resin was investigated (Young's modulus, Flexural strength). The micro-and nano composites were prepared by using three steps process with different volume fraction of micro-and nano particles (1, 2, 3, 4, 5, 7, 10, 15, and 20 vol. %). Flexural strength and Young's modulus of nano composites were increased at low volume fraction (max. enhancement at 4 vol.% ). However at higher volume fraction both Young's modulus and flexural strength decrease. Moreover, above, the mechanical properties are enhanced more than that of neat epoxy resin. The flexural strength decreases with increasing the volume fraction of micr
... Show MoreThis study involves the synthesis of a new class of silicon polymers, designated as P1-P7, derived from dichlorodimethylsilane (DCDMS) in combination with various organic compounds (Schiff bases prepared from different amines and appropriate aldehydes or ketones) [I-V] through condensation polymerization. The structures of all monomers and polymers were characterization by FTIR and 1HNMR spectroscopy (for some polymers). The results of thermogravimetric analysis (TGA) and differential scanning calorimetry DSC test show stable thermal behaviour. Polymers with a higher concentration of aromatic rings in their repeating structural units exhibited a higher temperature for weight loss, indicating increased thermal stability. Thermal meas
... Show MoreThe operation and management of water resources projects have direct and significant effects on the optimum use of water. Artificial intelligence techniques are a new tool used to help in making optimized decisions, based on knowledge bases in the planning, implementation, operation and management of projects as well as controlling flowing water quantities to prevent flooding and storage of excess water and use it during drought.
In this research, an Expert System was designed for operating and managing the system of AthTharthar Lake (ESSTAR). It was applied for all expected conditions of flow, including the cases of drought, normal flow, and during floods. Moreover, the cases of hypothetical op
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