CR-39 is a solid state nuclear track detector (SSNTD) that has been used in many research areas. In spite of the assumption that the CR-39 detectors are insensitive to beta and gamma rays, irradiation with these rays can have significant effects on the detector properties. In this study, beta and gamma rays mass attenuation coefficients μ/ρ (cm2 g-1) for the CR-39 detector have been measured using NaI(Tl) scintillation spectrometer along with a standard geometrical arrangement in the energy region of (0.546-2.274) MeV beta rays and standard gamma sources having energy 0.356, 0.5697, 0.6617 and 1.063 MeV. The total atomic cross-section (σtot), total electronic cross-section (σT E) and the effective atomic number (Zeff) of gamma rays at energy of 1keV- 105 MeV have been also calculated using the Winxcom and MathCAD programs. The data base and the calculated results were compared with the measured experimental values. It has been found that the mass attenuation coefficients vary with the type of interaction of radiation, photoelectric interaction gives dominant contribution to the total mass attenuation coefficients for CR-39 detectors. Further, the Zeff changes with change of energy.
الغرض من البحث دراسة تأثير ادارة المعرفة (استراتيجية الشخصنة والترميز) في تحقيق التفوق الاستراتيجي في بيئة المصارف الاهلية العراقية ، وتم اعتماد منهج البحث الوصفي والتحليلي ، لذا اعتمد الباحث الفلسفة الوضعية وفق المنهج الاستنباطي لغرض اشتقاق فرضية البحث الاولى من الجانب النظري وتوصل البحث الى مجموعة من النتائج اهمها ان استراتيجية الشخصنة حققت تقدماً كبيراً في قدرتها على التأثير في التفوق الاستراتيجي بوصف
... Show MoreThe theatrical field has witnessed a huge development that included the semantic and formal sides, considering that the theatrical experience has gone through a long period of description and the dominance of literature and linguistics, thus the theatrical experience has been open to many workings and uses of high quality in forming and composing the visual system. The semiotics had a role in presenting transformed sign forms and features generated in the theatrical space. Thus (costumes, décor, makeup, lighting, and actor) are considered elements with sign forms and attributes that together constitute integrated semiotic unit that include all the layouts in the scenographic space. The two researchers determined on semiotics due to its
... Show More
Roller Compacted Concrete is a type of concrete that is environmentally friendly and more economical than traditional concrete. Roller Compacted Concrete is typically used for heavy-duty and specialist constructions, such as hydraulic structures and pavements, because of its coarse surface. The main difference between RCC and conventional concrete mixtures is that RCC has a more significant proportion of fine aggregates that allow compaction and tight packing. In recent years, it has been estimated that several million tons of waste demolished material (WDM) produced each year are directed to landfills worldwide without being recycled for disposal. This review aimed to study the literature about creating a Roller-Comp
... Show More
(1)
(2)
(48)
(47)
We study the physics of flow due to the interaction between a viscous dipole and boundaries that permit slip. This includes partial and free slip, and interactions near corners. The problem is investigated by using a two relaxation time lattice Boltzmann equation with moment-based boundary conditions. Navier-slip conditions, which involve gradients of the velocity, are formulated and applied locally. The implementation of free-slip conditions with the moment-based approach is discussed. Collision angles of 0°, 30°, and 45° are investigated. Stable simulations are shown for Reynolds numbers between 625 and 10 000 and various slip lengths. Vorticity generation on the wall is shown to be affected by slip length, angle of incidence,
... Show More
(13)
(13)
(2)
(1)
(1)
(1)
(15)
(13)