In the current work various types of epoxy composites were added to concrete to enhance its effectiveness as a gamma- ray shield. Four epoxy samples of (E/clay/B4C) S1, (E/Mag/B4C) S2, (EPIL) S3 and (Ep) S4 were used in a comparative study of gamma radiation attenuation properties of these shields that calculating using Mont Carlo code (MCNP-5). Adopting Win X-com software and Artificial Neural Network (ANN), µ/ρ revealed great compliance with MCNP-5. By applying (µ/ρ) output for gamma at different energies, HVL, TVL and MFP have been also estimated. ANN technique was simulated to estimate (µ/ρ) and dose rates. According to the results, µ/ρ of all epoxy samples scored higher than standard concrete. Both S2 and S3 samples having higher values of µ/ρ, show minimum dose rate values. (µ/ρ) and RPE% values were enhanced, the concrete containing E/Mag/B4C (S2) had the best results, while the concrete containing Ep (S4) provide the worst results. The ANN prediction results take 15 sec for estimating gamma doses corresponding to seventeen shield thicknesses, while the theoretical MCNP-5 results took approximately between 7 to 10 hours for five gamma doses. ANN provides excellent predictions with a high degree of correlation depending on increasing the number of attenuation parameters used in the training process. Also, it predicts gamma dose rates for a large number of shield thicknesses that cannot be calculated theoretically in a very short time. This supports, the created epoxy composite offers good attenuation properties for many shielding applications and could be proposed as an injecting mortar for cracks in biological shields and the walls of diagnostic and radiotherapy rooms. However, further investigations are planned for different filler ratios, for comparison purposes, in order to reach optimal shielding properties
ليست الادارة المحلية أو نظام الحكم المحلي ابتكاراُ حديثاً للانسان، بل أنه لازم البشرية منذ أقدم العصور وحتى الآن، إذ الملاجظ أن القرى الصغيرة نشأت قبل أن تنشئ الدولة أو قيل أن يتبلور مفهوم الدولة في الوقت الحاضر وكانت القرى والمدن تجتمع بين حين وأخر- اجتماع أفرادها- لادارة شؤونهم وحل مشاكلهم، وكان هذا خير دليل لتطبيق مفهوم الديمقراطية المباشرة بين أفراد المجتمع الواحد، ولذلك فإن الحك
... Show Moreהתמצית השניות היא התורה שנזכרת כי המוצאים בלשון הערבית וכך בלשונות השמיות אינם הבטויים בעלי האותיות השלושיות , אלא בעלי שתי אותיות . לפי כך אפשר להשיב השורשים השלושיים לשורשים השניים . וכל אות שנאספה בשורש שׁניוני, יהיה לפי חוק ההתפתחות הלשונית , הוספות תחילית , תוכית , סופית , עם השארת החיבור המשמעתית בין השׁניוני והשׁלשׁי כמו היא ממושכת בין השׁלשׁי והרביעי ומה שרבה ההוספות . השרשים השניים מוצאים הם: אות וה
... Show Moreان العقد – في تكوينه – عبارة عن اتفاق ارادتين من اجل احداث اثر قانوني معين ، بيد ان العقد نفسه – في آثاره – يخضع لمجموع الالتزامات التي تشكلت طبقاً لما انصرفت اليه ارادة طرفيه ، فضلاً عمّا تيسّر من احكام اخرى فرضها المشرع او العرف او العدالة او مبادئ حسن النية .
أسلوب العطف: دراسة مقارنة بين اللغة العربية والاسبانية
This paper shed light on castles in Iraq through Othman reign to know their sorts , and studying planning concentrating on the nature of architecture , this is a serious trying to study and important side of military architecture in Iraq with its reasons of building them which had related with political, military , social ,and economical circumstances of country .
The argumentation find its origins in some conceptions laid by Aristote. A speaker always intends to influence his hearers to change their beliefs. Therefore, this study deals with texts of the political speech of the French presidents Nicolas Sarkozy and François Hollande in the treatment of argumentative strategies.
Financial compensation contracts related to Hajj
In this work, an experimental study has been done to expect the heat characteristics and performance of the forced-convection from a heated horizontal rectangular fins array to air inside a rectangular cross-section duct. Three several configurations of rectangular fins array have been employed. One configuration without notches and perforations (solid) and two configurations with combination of rectangular-notches and circular-perforations for two various area removal percentages from fins namely 18% notches-9% perforations and 9% notches-18% perforations are utilized. The rectangular fins dimensions and fins number are kept constant. The fins array is heated electrically from the base
... Show MoreThe research aims to verifying the tax exemptions granted in accordance with the Iraqi tax legislations, showing their suitability for basic tax rules, and identifying their role to reduce the tax evasion phenomenon and the negative effects resulting therefrom, which arerepresented by a decrease in the proceeds of tax revenue and therefore leadings to a reduction of public revenues of the state. Also, the research tries to identify the ways to reduce cases of tax evasion due to their reflection positively on the public budgetof the state. The data of the research was collected through two models of questionnaires distributed to a sample of taxpayers from some professions and a sample of the tax administration staff. The research has reac
... Show MoreDielectric barrier discharges (DBD) can be described as the presence of contact with the discharge of one or more insulating layers located between two cylindrical or flat electrodes connected to an AC/pulse dc power supply. In this work, the properties of the plasma generated by dielectric barrier discharge (DBD) system without and with a glass insulator were studied. The plasma was generated at a constant voltage of 4 kV and fixed distance between the electrodes of 5 mm, and with a variable flow rate of argon gas (0.5, 1, 1.5, 2 and 2.5) L/min. The emission spectra of the DBD plasmas at different flow rates of argon gas have been recorded. Boltzmann plot method was used to calculate the plasma electron temperature (Te), and Stark broadeni
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