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.
ارتبط الانسان بالطبيعة بأشكالها المختلفة ارتباطا وثيقا ، فهي تمثل الحاضنة له بمجالات حياته كلها، فما كان من الأدباء الا أن يجعلوها في كثير من الأحيان مادة لأدبهم وأرضية خصبة لنتاجهم، فتمظهرت بصورها المختلفة وحاجة الانسان لها وخيرها وشرها في الأدب على مدى التاريخ، والعرب شأنهم شأن غيرهم من الأمم فمنذ عصر ما قبل الاسلام كانت الطبيعة منفذا مهما وملجأ للشعراء في انتاج الأدب وابداعه وإلى يومنا هذا، ونحن إذ نتحد
... Show MoreThe problem of the study lies in the need for standing on the justifications, reasons and difficulties that face the scientific research matter at Baghdad university. The importance of this study lies in the fact of being scientific research one of the most important methods in developing the teaching members performance efficiency which contributes in teachers contact with the modern developments that emerge in work. That matter which reflexe on the educational process and the scientific production in their universities.
And the research goal is summarized in identifying the difficulties that is facing the scientific research at Baghdad university from the point of view of the lecturers, and also to ide
... Show Moreمكانية استخدام السوق المالية في التنبؤ بالدورات الاقتصادية
Despite all the possibilities, owned by Iraq for the production of fish, but there is low in the level of production and in the rate of per capita consumption is due to inter alia, the weakness of investment, stop government support, a significant decline in the quantities of water, the high proportion of salinity and the proportion of pollution in the water, the use of means and fishing methods are primitive, weak laws and legislation, the policy of dumping markets imported products. Despite all this research has shown that there are investment opportunities very large in this sector through the size of the market and the absorptive capacity and the growth of per capita income and cultural revelation
This study tested the impact of region and gender on adolescents 'stress perceptions and coping styles. A total sample of 650 adolescents (5 9.4% female) from 2 countries (Iraq - Algeria). Samples of n = 325 were drawn from each country completed questionnaires on stress and coping behaviors in four domains (school, parents, peer, and future). Results revealed that levels of perceived stressfulness of issues in different domains were universally similar among adolescents from the two countries. School-related stress received the highest rankings, Parent- , future-, peer-related stress, ranked (second, third, and fourth) respectively. Differences emerged with respect to coping style depending on region and gender. Coping sty
... Show Moreملخص البحث
العولمة ظاهرة اقتصادية سياسية اجتماعية لها انعكاساتها المختلفة على المجتمعات وعلى منظمات الأعمال في مختلف دول العالم، هذه الظاهرة أدت إلى المزيد من النتائج التي زادت منظمات الأعمال في الدول الغنية غناً وزادت منظمات الأعمال في دول العالم الثالث فقر، وقد ترتب على ذلك نتائج ايجابية لدى المجتمعات الغربية والمؤتلفة معها بسبب سيطرة منظمات الأعمال في تلك الدول على الأسواق في البلدان الن
... Show MoreBackground: Beta-thalassemia major is the most common monogenic known disorder in the Middle East, characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic Individuals. This study aimed to evaluate salivary flow rate and salivary IgA in β-thalassemia major patients. Since many oral and systemic conditions manifest themselves as changes in the flow and composition of saliva the dental practitioner is advised to remain up-to-date with this issue. Materials and methods: The study samples consist of (60) subjects, patients group composed of (30) patients with β –thalassemia major, age rang (5-23) years and (30) healthy locking
... Show MoreIn this research a local adsorbent was prepared from waste tires using two-step pyrolysis method. In the carbonization process, nitrogen gas flow rate was 0.2L/min at carbonization temperature of 500ºC for 1h. The char products were then preceded to the activation process at 850°C under carbon dioxide (CO2) activation flow rate of 0.6L/min for 3h. The activation method produced local adsorbent material with a surface area and total pore volume as high as 118.59m2 /g and 0.1467cm3/g, respectively. The produced . local adsorbent (activated carbon) was used for adsorption of lead from aqueous solution. The continuous fixed bed column experiments were conducted. The adsorption capacity performance of prepared activated carbons in this work
... Show MoreThe research focuses on the withdrawal of the United States from the nuclear agreement signed between the permanent members of the United Nations Security Council and the Islamic Republic of Iran concerning its nuclear program. This withdrawal has caused disruption in the official media discourse of the concerned countries. Therefore, the main question can be posed: Are there differences in the positions of countries related to the nuclear agreement, as well as those countries affected by it, before and after the official withdrawal of the United States on May 8, 2018?
The research aims to shed light on the trends in media discourse of the countries that signed the nuclear agreement and those affected by it b
The aim of this research is to measure and analyze the gap between the actual reality and the requirements of the environmental management system in the middle refineries company/refinery cycle according to ISO14001: 2015, as well as to measure the availability of a clean production strategy and test the relationship and impact between the availability of the requirements of the standard and a clean production strategy for the actual reality in the company.
The research problem was determined by the extent to which the requirements of the environmental management system are applied according to ISO14001: 2015 in the middle refineries company? To what extent are the required clean production strategies ava
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