In this work, two cone-inverted cylindrical and cross-hybrid dielectric resonator antennas are stacked and excited by the coaxial probe method with an operating standard resonant frequency of 5.438 GHz. A drawback of these standard Dielectric Resonator Antennas (DRAs) is their narrow bandwidth. For good antenna performance, a stacked DR geometry and a thick dielectric substrate having a low dielectric constant are desired since this provides large bandwidth, better radiation power, reduces conductor loss and nonappearance of surface waves. Many approaches, such as changing the shape of the dielectric resonator, have been used to enhance bandwidth. Using DRA, having the lowest dielectric constant, increases the bandwidth and the electromagnetic energy. In the current work, bandwidth improvement was significantly achieved by the proposed geometry by varying the antenna size. A novel hybrid DRA configuration is used to increase the bandwidth of the antenna to 89.27% and 149.23% due to cone-inverted cylindrical and cross-hybrid dielectric resonator antennas, respectively. The DRA is designed numerically via Finite Difference Time Domain (FDTD) method. Several parameters like return loss, input impedance (verified at ) and radiation pattern are calculated. Furthermore, the stacked-hybrid technique is used to enhance the antenna's performance which is useful for broadband communication and the demand of wireless.
تتطلب عملية التنمية الاقتصـادية في الدول النامية مبالغ كبيرة من رؤوس الأمـوال اللازمة لتنفيذ البرامج والخطط الاقتصادية، ولما كانت الاسـتثمارات التي تنفذها هذه الدول خلال حقبة معينة، تزيد على ما تم تحقيقه من موارد مالية محلية، فلابد أنْ يمول الفرق من خلال انسياب صافٍ لرأس المال الأجنبي (قروض ومساعدات) إلى الداخل خلال المدة نفسها، لغـرض سَدّ الفجوة في المـوارد المحلية المعدة للاسـتثمار، وعانت بعض د
... Show MoreThe management of the overall quality (TQM)) of the philosophies that gained the attention of a large number of leaders and managers, practitioners and academics, as one of the prevailing management philosophies and desirable in the current period, is associated with the concept of quality itself, which shows the overall features and characteristics and attributes that related to the service and meet the needs of beneficiaries phenomenon and full, as was the concept of strategic performance with a significant level of interest from organizations because it is closely linked to the success of the organization in light of the changing competitive environment. These were the study in an attempt to see how a clear vision of the unive
... Show Moreالمُستلخص:
يتناول هذا البحث موضوعاً يتركز في جانب تحديد مفهوم ومحتوى الإستراتيجية. وقد أشارت الأدبيات إلى عدد من المحاولات التي هدفت إلى تلمس مفهوم ومحتوى الإستراتيجية في منظمات الأعمال، غير أن تلك المحاولات- على الرغم من ندرتها- كانت تتسم بغلبة الأطر النظرية والتعبير عن المفهوم، بالإستناد إلى حوارات فكرية وإرهاصات ذات علاقة بمفهوم ومحتوى الإستراتيجية.
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... Show Moreتلعب الاعتمادات المستندية دوراً كبيراً وخطيراً في التجارة الدولية باعتبارها إحدى أوسع أدوات الدفع انتشاراً في العالم سواءاً كان ذلك بالنسبة للمستورد أم للمصدر وتغطيتها للمخاطر المحتملة لكلا الطرفين، فهي تؤمن للمصدر استلام قيمة البضاعة بالكامل عند تنفيذها لشروط العقد، ويسمح للمستورد بعدم الدفع إلا بعد إتمام شحن البضاعة وتقديم المستندات المطلوبة واستلامها.
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... Show MoreThe study tackles the market orientation and the organizational learning as independent variables each included three sub-dimensions, and the variable of business performance as affiliated variable. These three variables have interacted to form the framework around which the study revolves. Since the banking sector has become an important part of which service sector is made, as well as it represents the basic pivot for the process of building and the development of the economies of countries, the Iraqi banking sector have been taken to be the sample of this study. A nonrandom sample of nine Iraqi banks was chosen, including four state banks (Al-Rafdain, Al-RaSheed, Industrial Bank, and Agricultural), and five private banks (Bagh
... Show MoreAbstract
The health section is considered to be one of the most important section in the field of service economical and social unit because of its concern in the life of human begin and society and the process of determining t
... Show MoreFrancisco de Quevedo is a well-known man of letters in the Golden Age of Spanish literature. He is the witness who related to us, in his works, the Spanish community in that era. He showed in most of his writings the political weakness of Spain, and made prominent the remarkable literary aspect of Spain. He had a very good tlent for poetry, and a rather polite style in exploiting colloquialisms in his literary writings. He wrote about philosophy, where his most prominent work was "The cradle and the grave". The writer was also very well-known for his puns which were employed to clarify his inner thoughts regarding the Spanish situation at that time.
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... Show MoreThis research work dealt with the problem of layout the production line of engine of fan roof at the General Company for Electrical Industries (GCEI). It was observed that the assembly line of engine was unstable and subject to severe fluctuations. In addition the execution of tasks at some stations was observed to be very fast while at other stations was slow. This phenomenon resulted into bottlenecks between workstations, idle time, and work in process. The system design was used to assign tasks to work stations according to different heuristics (Ranked Positional weight techniques, longest Task Time, Most following tasks, Shortest tasks time, Least number of following task).
The study revealed that th
... Show MoreThe reaction oisolated and characterized by elemental analysis (C,H,N) , 1H-NMR, mass spectra and Fourier transform (Ft-IR). The reaction of the (L-AZD) with: [VO(II), Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)], has been investigated and was isolated as tri nuclear cluster and characterized by: Ft-IR, U. v- Visible, electrical conductivity, magnetic susceptibilities at 25 Co, atomic absorption and molar ratio. Spectroscopic evidence showed that the binding of metal ions were through azide and carbonyl moieties resulting in a six- coordinating metal ions in [Cr (III), Mn (II), Co (II) and Ni (II)]. The Vo (II), Cu (II), Zn (II), Cd (II) and Hg (II) were coordinated through azide group only forming square pyramidal
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