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Go to Editorial ManagerThe polyethylene terephthalate (PET) was prepared from PET flakes of empty local water drinking bottles and diagnosis by infrared spectroscopy (IR). The glass transition temperature, melting temperature T m and heat capacity were indicated by differential scanning calorimeter (DSC). Part hundred ratios (phr , s) of (PET) were added to study its effect on concrete properties. Additives of (phr) impart performance such as increased cement dispersion, enabling drastically reduced water requirements. Enhance the mortar cubes performance; depend on the compatibility of cement with PET. Porosity of mortar cubes with cement, sand and added PET products were calculated. Maximum and minimum Compressive strength were calculated 58.76 MPa, and 24.0 MPa at phr 0.04 and 0.07 of PET with cement. And PET with cement and sand were calculated 16.5 MPa and 4 MPa at dosages 0.03 gm. and 0.08 gm. The relative dosages in calculating porosity percentages are (0.06, 0.1 and 0.3) gm.
The present investigation's main goal is to assess butt joint and T-joint plates containing misalignment, undercut and porosity welding defects by studying the influence of the defect’s parameters on the fatigue life. The fatigue life is predicted using ANSYS ver. 19 Software. The results of finite element analysis are used in the regression analysis to find relationship between the fatigue life and defects parameters. The findings demonstrated that finite element modeling and the pervious published experimental tests were in good agreement with maximum error percentage 4 %. The fatigue life differed substantially depending on the defect’s parameters.
This numerical study aims to enhance the heat transfer efficiency by dissipating the heat Emitted from electronic processors. A jet impingement technique is utilized with porous layer covering a metal fin as a heat sink. Forced convection and normal convection (due to the buoyancy effect) are taken into consideration. The two equations model (Local Thermal Non-Equilibrium LTNE) employed to describe the energy equations of the two phases of the porous surface. Finite Element Method (FEM) used to discretize these equations to obtain the numerical solution. To make this study closest to the reality, constant heat flux boundary condition is applied underneath the metallic heat sink. The geometry comprises of three domains: Free flow channel, Porous layer and Metal fined heat sink. In order to simulate the heat transfer, isotherms; streamlines and Nusselt number have been considered. Investigation has been done by inspecting the effects of the pertinent non- dimensional parameters such as: Reynolds number ( Re = 100-900), Darcy number ( Da = 10 -1 -10 -6 ), Richardson number ( Ri = 0.1-100) and Porosity ( ε = 0.85-0.95). The results show that increasing Re and decreasing ε lead to enhance Nusselt number. Richardson number below 100 has no significant effects on Nu . At Re above 400, Nusselt number proportional with Darcy number. The enhancement of Nusselt number is found to be 250 % by increasing Re from 100 to 900, 290 % by decreasing ε from 0.95 to 0.85 and about 13 % by increasing Darcy number from 10 -6 to 10 -1 .
The studying of fluid flow throughout fracture in the reservoir is one of the most vital subjects attracted much attention from engineers and geologists. In the present paper, the Dual Porosity-Dual Permeability (DPDP) model has been applied to represent the fluid flow within the fractured reservoirs. This work aimed to demonstrate the utility of the fractures in the petroleum reservoir and how could be used the positive effect of these fractures on the productivity as well. The productivity of single-phase fluid flow within the single horizontal fracture, multi horizontal fractures, and inclined fracture with different orientations (20 o , 30 o , 45 o , and 70 o ) have been implemented by using ANSYS- CFX program and compared with the productivity of conventional (without fractures) reservoirs. In addition to, visualize the velocity streamlines within fracture and matrix zones for the DPDP model. To verify this work the comparison has been made with published paper, which studies the fluid flow through fractures, and a good agreement has been obtained with each other. The study indicates that the presence of macro scale fractures in petroleum reservoirs contributes to increasing the total productivity of these reservoirs. Clearly, the productivity index of multi-horizontal fractures domain is more than twice of nonfractured domain. It is also clear that, when comparing the fractured and nonfractured reservoir, the improvement percentage of the productivity index reaches to (71.8) for a single horizontal fracture with 9 ft length. While this percentage would be about (116.88) if the fracture is inclined with 20 o .
This paper studies and compared the fatigue crack propagation rate da/dN for three kinds of ceramic wheel (model A, model B, and model C) made of Si3N4 ceramic with different additives used for gas turbine application. The stress intensity factor range was calculated using finite element method and then compared with analytical approximate approaches. Experimental fatigue test was carried out on the three specimens taken from the models. As a result, the types of additives effect on fatigue crack propagation rate. The model A has the highest da/dN values and model C exhibits the lower values of da/dN.
In this study the powder metallurgy technique was used to prepare the composite materials using the aluminum powder as the basis metal, with the additions of the 2, 4 and 6%Wt. of ZrO2-Cu coating and mixing it manually for 15 minutes at (30-32 oC). Then the mixture are compacted at pressure 320 MPa and sintering at 640oC in the atmosphere furnace with argon gas protection. The physical properties include the green density, sintering density, porosity, and microstructure were examined for the prepared samples. X-ray analyzer was used to identify the phases changes in order to find the chemical reaction which it can be excepted occurred in the sintering samples. The result of X-Ray diffraction shows that there is new phase exist after sintering for all weight percentage.