The fatigue is one of the major reasons for fracture of materials. Aluminum 7204 AA alloy with various heat treatments and (2.0) wt % of SiC nanoparticles were prepared by stir-casting method under rotating bending loading with ratio of stress (R= -1). The composite was strengthened by SiC particles size of) 10 (nanometre. The fatigue strength and life were obtained experimentally by the family of S-N curves for different heat treatments. The endurance limits (107cycles) for 7204 AA/ 2.0wt% SiC nano-composite fatigue strength as related to untreated nanocomposite was enhanced by 72 and 78.5% for T4 and T6, respectively.The improvement of fatigue properties is due to better spreading of SiC nanoparticles and increased porosity.
A huge potential from researchers was presented for enhancing the nonlinear optical response for materials that interacts by light. In this work, we study the nonlinear optical response for chemically prepared nano- fluid of silver nanoparticles in de-ionized water with TSC (Tri-sodium citrate) protecting agent. By the means of self-defocusing technique and under CW 473 nm blue laser, the reflected diffraction pattern were observed and recorded by CCD camera. The results demonstrate that, the Ag nano-fluid shows a good third order nonlinear response and the magnitude of the nonlinear refractive index was in the order of 10−7 cm2/W. We determine the maximum change of the nonlinear refractive index and the related phase shift for the mat
... Show MoreThis study was carried out in the botanical garden / department of biology /college of science in Mustansiriyah University, Baghdad. During spring 2017 under controlled environmental conditions in greenhouse to study the role of Nano ZrO2 activity in decrease negative effect of salinity under two levels from NaCl . The treatments included (Salinity levels : natural soil , 3000 ppm and 6000 ppm NaCl) and ( Applications : control , 100 , 300 Zirconium oxide , 5 ppm of liquorice root extract and 10 ppm liquorice root extract and 300 ppm GA3) , The collected data were analyzed statistically using factorial completely randomized design. The results appeared that 300 ppm nano zirconium gave the highest
... Show MoreThis research aims at studying the relation between fair value and the Financial Reports Quality to achieve a number of aims such as :-
1- Throw light on the problems of the measurement that depends on the historic cost as it paves the way towards the method of the fair value in the accounting measurement.
2-Give a general definition for fair value in the accounting via analyzing the theoretical aspects that relates the subject and the scientific bases on which the relating accounting treatment depend.
3- Exhibit the characteristics that could be added by the fair value to the accounting Information .
The study problem is summarized in that the e
... Show MoreNano γ-Al2O3 support was prepared by co-precipitation method by using different calcination temperatures (550, 600, and 750) oC. Then nano NiMo/γ-Al2O3 catalyst was prepared by impregnation method were nickel carbonate (source of Ni) and ammonium paramolybdate (source of Mo) on the best prepared nano γ-Al2O3 support at calcination temperature 550 oC. Make the characterizations for prepared nano γ-Al2O3 support at different temperatures and for nano NiMo/γ-Al2O3 catalyst like X-ray diffraction, X-ray fluorescent, AFM, SEM, BET surface area, and pore volume.
The N
... Show MoreThe curing process of epoxy resin was investigated with some additives and fillers such as nano fumed silica with primary particle diameter of 56–58 nanometers, fine ferric oxide with an average particle diameter of 0.4 micrometer, fine calcium carbonate with an average particle diameter of 0.58 micrometer, and plasticizer, a new composite resin has been obtained. Based on present experimental results, the new composite resin shows high impact strength and hardness as well as the ability of the composite withstand to degradation from water way in. Additionally, curing time of composite was reduced to the minimum set time than epoxy resin at different temperature. This new composite resin was used appropriately for coating to protect su
... Show MoreThe study entitled (Anthropometric Treatments of the Study Seat Units Used in Elementary stages) highlighted the relations between the sizes of dimensions of the study seats and the different anthropometric sizes of the students. The study problem is manifested in the following question: what are the anthropometric treatments used in the design of the study seats in the elementary stages? The research aims at finding design treatments for the anthropometric variables of the study seats used in the elementary stages, because the study seats have to do with preserving students health and safety through providing an ideal seating mechanism compatible with the anthropometric variables which enhances comfort, safety and focus in the mo
... Show MoreAbstract
The aim of this paper is to model and optimize the fatigue life and hardness of medium carbon steel CK35 subjected to dynamic buckling. Different ranges of shot peening time (STP) and critical points of slenderness ratio which is between the long and intermediate columns, as input factors, were used to obtain their influences on the fatigue life and hardness, as main responses. Experimental measurements of shot peening time and buckling were taken and analyzed using (DESIGN EXPERT 8) experimental design software which was used for modeling and optimization purposes. Mathematical models of responses were obtained and analyzed by ANOVA variance to verify the adequacy of the models. The resul
... Show More