تنتاب العلاقةَ الأمريكية الإيرانية تجاذباتٌ ومشاحنات أدخلت العالم في حالة من الغموض السياسي، وجعلت بعض المراقبين والمحللين السياسيين لا يستبعدون توجيه الولايات المتحدة الأمريكية أو إسرائيل ضربة عسكرية لإيران، إذ يرى المدقق في واقع تلك العلاقة المضطربة: أن الأمور كلما بلغت حافة الهاوية عادت من جديد إلى ساحة الحوار والمفاوضات، ويبدو: أن الإستراتيجية الأمريكية التي يتبعها الرئيس (باراك أوباما) تقوم على: "التعايش" مع إيران الإسلامية، والاعتراف بها بوصفها قوة إقليمية، ما دامت قد أزالت "الغموض" بخصوص برنامجها النووي، وما دام التزمت بـ"الخطوط الحمراء" الأمريكية الخاصة بعدم امتلاك السلاح النووي. وهذه الدراسة محاولة لقراءة طبيعة العلاقات الأمريكية_الإيرانية في عهد الرئيس اوباما، والإجابة عن بعض التساؤلات فيما يخص ذلك في المحاور الثلاثة الآتية: - الإطار العام للعلاقات الأمريكية_الإيرانية منذ العام 1979م. - قضايا الأمن القومي المرتبطة بإيران بالنسبة للرئيس اوباما. - الإدراك الإيراني للمخاطر في البيئة الدولية الجديدة بعد انتهاء الحرب الباردة.
The effective insulation design of the stress grading (SG) system in form-wound stator coils is essential for preventing partial discharges and excessive heat generation under pulse-width modulation excitation. This paper proposes a method to find the optimal insulation design of the SG system aimed at reducing the dielectric and thermal stresses in the machine coil. The non-uniform transmission line model is used to predict the voltage propagation along the overhang, SG, and slot regions considering the variation in the physical properties of the insulation layers. The machine coil parameters for different insulation materials are calculated by using the finite element method. Two optimization algorithms, fmincon and particle swarm optimiz
... Show MoreDue to restrictions and limitations on agricultural water worldwide, one of the most effective ways to conserve water in this sector is to reduce the water losses and improve irrigation uniformity. Nowadays, the low-pressure sprinkler has been widely used to replace the high-pressure impact sprinklers in lateral move sprinkler irrigation systems due to its low operating cost and high efficiency. However, the hazard of surface runoff represents the biggest obstacle for low-pressure sprinkler systems. Most researchers have used the pulsing technique to apply variable-rate irrigation to match the crop water needs within a normal application rate that does not produce runoff. This research introduces a variable pulsed irrigation algorit
... Show MoreThis study reports testing results of the transient response of T-shape concrete deep beams with large openings due to impact loading. Seven concrete deep beams with openings including two ordinary reinforced, four partially prestressed, and one solid ordinary reinforced as a reference beam were fabricated and tested. The effects of prestressing strand position and the intensity of the impact force were investigated. Two values for the opening’s depth relative to the beam cross-section dimensions were inspected under the effect of an impacting mass repeatedly dropped from different heights. The study revealed that the beam’s transient deflection was increased by about 50% with gre
This experiment was holdup in A-Faris poultry farms from 1st March to 11 of Aprile 2019. (ACTH) hormone infusion was tested in this experiment on acid-base regulation in broiler chickens. For 7 days, osmotic pumps dispensed 8 IU of ACTH in saline/kg of BW/d, or the same volume of saline as in ACTH at 1 l/h. On days 0 and 14, after the beginning of the infusions, blood samples were obtained to establish a baseline. The plasma concentrations of Na+, K+, and Cl- were decreased, whereas the partial pressure of CO2, anion gap, corticosterone, mean corpuscular hemoglobin concentration, and blood concentrations of hemoglobin and HCO - were all elevated due to the ACTH administration. When given ACTH, neither blood pH nor plasma Ca2+ levels changed
... Show MoreIn this work, a single pile is physically modeled and embedded in an upper liquefiable loose sand layer overlying a non-liquefiable dense layer. A laminar soil container is adopted to simulate the coupled static-dynamic loading pile response during earthquake motions: Ali Algharbi, Halabjah, El-Centro, and Kobe earthquakes. During seismic events with combined loading, the rotation along the pile, the lateral and vertical displacements at the pile head as well as the pore pressure ratio in loose sandy soil were assessed. According to the experimental findings, combined loading that ranged from 50 to 100% of axial load would alter the pile reaction by reducing the pile head peak ground acceleration, rotation of the pile, and lateral displacem
... Show MoreIn order to understand the effect of the number of piles (N), the history response of dynamic pile load in piled raft system and deflection time history of piled raft under repeated impact load applied on the center of piled raft resting on loose sand, laboratory model tests were conducted on small-scale models. The results of experimental work are found to be dynamic load increase with increase height of drop, the measured repeated dynamic load time history on the center of piled raft was close approximately to three a half sine wave shape with small duration in about (0.015 Sec). The maximum peak of impact loads occurs in pile and deflection time history occur after at the time of the peak repeated impact loads, dynamic pile load
... Show MoreThere has been a growing interest in the use of chaotic techniques for enabling secure communication in recent years. This need has been motivated by the emergence of a number of wireless services which require the channel to provide very low bit error rates (BER) along with information security. As more and more information is transacted over wireless media, there has been increasing criminal activity directed against such systems. This paper investigates the feasibility of using chaotic communications over Multiple-Input-Multiple-Output (MIMO) channels. We have studied the performance of differential chaos shift keying (DCSK) with 2×2 Alamouti scheme and 2×1 Alamouti scheme for different chaotic maps over additive white Gaussian noise (
... Show MoreTwo field experimسents were conducted in one of the fields of the Agriculture Division of Ain Al-Tamr /Holy Karbala Governorate at two sites of different textures during the agricultural season 2020/2021. The first site has sandy loam texture (gypsum soils). The second site has loamy sand texture (calcareous soils). The factors of the study included: The first factor included two types of soil, gypsum and calcareous soil. The second factor is the tillage systems (no-tillage, spring spike harrows, disc harrows, and mold board plow). The experiment was designed in the two study sites according to the RCBD with three replications. The Valley type center pivot irrigation system was evaluated before planting, three speeds, 30, 50 and 100% of th
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