This paper focuses on the optimization of drilling parameters by utilizing “Taguchi method” to obtain the minimum surface roughness. Nine drilling experiments were performed on Al 5050 alloy using high speed steel twist drills. Three drilling parameters (feed rates, cutting speeds, and cutting tools) were used as control factors, and L9 (33) “orthogonal array” was specified for the experimental trials. Signal to Noise (S/N) Ratio and “Analysis of Variance” (ANOVA) were utilized to set the optimum control factors which minimized the surface roughness. The results were tested with the aid of statistical software package MINITAB-17. After the experimental trails, the tool diameter was found as the most important factor that has effect on the surface roughness. The optimal drilling factors that minimized the surface roughness are (20mm/min cutting speed, 0.2 mm/rev feed rate, and 10mm tool diameter).
Rheumatoid arthritis and periodontitis use analogous effector destructive procedures, in that the inflammatory cells and pro-inflammatory cytokines that drive chronic bone erosion in RA and chronic periodontal destruction in Periodontitis are alike. Periodontitis (PD) has appeared as a hazard factor in a number of health situations as rheumatoid arthritis (RA). To determine the effect of anti-tumor necrosis factor alpha biological treatment (methotrexate and Enbrel or infliximab) on periodontal status of patients having rheumatoid arthritis with periodontitis in comparison to those having periodontitis without rheumatoid arthritis and control healthy subjects and to determine the serum levels of anti-cyclic citrullinated peptide (ACCP) in t
... Show MoreThe subject of an valuation of quality of construction projects is one of the topics which it becomes necessary of the absence of the quantity standards in measuring the control works and the quality valuation standards in constructional projects. In the time being it depends on the experience of the workers which leads to an apparent differences in the valuation.
The idea of this research came to put the standards to evaluate the quality of the projects in a special system depending on quantity scale nor quality specifying in order to prepare an expert system “ Crystal “ to apply this special system to able the engineers to valuate the quality of their projects easily and in more accurate ways.
An experiment was conducted in the plastic house of the Botanical Garden in the Department of Biology, College of Education for Pure Sciences (Ibn Al-Haitham), University of Baghdad during one growth season. The experiment included the study of the effect of three concentrations of citric acid (0, 75, 150) mg. L-1 and four concentrations of malic acid (0, 50, 100, 150) mg. L-1 and their interaction in some of the growth and yield parameters of the broad bean plant, plant height, dry weight, number of leaves, total chlorophyll content, the number of flowers and pods and the weight of the pod. The experiment was carried out in full random design (4× 3) and with three duplicates, the results showed a significant effect of citric and malic aci
... Show MoreThe present research aims to study the effect of friction stir welding (FSW) parameters on temperature distribution and tensile strength of aluminum 6061-T6. Rotational and traverse speeds used were (500,1000,1400 rpm) and (14,40,112 mm/min) respectively. Results of mechanical tests showed that using 500rpm and 14mm/min speed give the best strength. A three- dimensional fully coupled thermal-stress finite element model via ANSYS software has been developed. The Rate dependent Johnson-Cook relation was utilized for elasto-plastic work deformations. Heat-transfer is formulated using a moving heat source, and later used the transient temperature outputs from the thermal analysis to determine equivalent stresses in the welde
... Show MoreSb-dopedAgInSe2 (AIS: 3%Sb)thin films were synthesized by thermal evaporation with a vacuum of 7*10-6torr on glass with (400+20) nm thickness. X-ray diffraction was used to show that Sb atoms were successfully incorporated into the AgInSe2 lattice. Then the thin films are annealed in air at 573 K. XRD shows that thin films AIS pure, AIS: 3%Sb and annealing at 573 K are polycrystalline with tetragonal structure with preferential orientation (112).raise the crystallinity degree. The Absorption spectra revealed that the average Absorption was more than 60% at the wavelength range of 400–700 nm. UV/Visible measure shows the lowering in energy gap to 1.4 eV forAIS: 3%Sb at 573 Kt his energy gap making these samples suitable for p
... Show MoreThe present paper deals with studying the effect of electrical discharge machining (EDM) and shot blast peening parameters on work piece fatigue lives using copper and graphite electrodes. Response surface methodology (RSM) and the design of experiment (DOE) were used to plan and design the experimental work matrices for two EDM groups of experiments using kerosene dielectric alone, while the second was treated by the shot blast peening processes after EDM machining. To verify the experimental results, the analysis of variance (ANOVA) was used to predict the EDM models for high carbon high chromium AISI D2 die steel. The work piece fatigue lives in terms of safety factors after EDM models were developed by FEM using ANSY
... Show MoreIn this study, the effect of design parameters such as pipe diameter, pipe wall thickness, pipe material and the effect of fluid velocity on the natural frequency of fluid-structure interaction in straight pipe conveying fully developed turbulent flow were investigate numerically,analytically and experimentally. Also the effect of support conditions, simply-simply and clamped-clamped was investigated. Experimentally, pipe vibrations were characterized by accelerometer mounted on the pipe wall. The natural frequencies of vibration were analyzed by using Fast Fourier Transformer (FFT). Five test sections of two different pipe diameters of 76.2
mm and 50.8 mm with two pipe thicknesses of 3.7 mm and 2.4 mm and two pipe materials,stainles
The objective of the present study was to investigate the effect of body mass index (BMI) on semen parameters, level of sex hormone and sperm DNA integrity. Semen samples were collected from (85) infertile men and (40) healthy fertile men with range of age (38.191 ± 0.84) years during their attendance at High Institute of Infertility Diagnosis and ART, Al-Nahrain University from March to June 2016. Semen samples were obtained by masturbation after 72 hours of abstinence. Seminal fluid analyses included semen volume, sperm concentration, percent sperm motility, percent sperm morphology, and sperm chromatin integrity DNA fragmentation index (DFI]). Serum samples were collected from each subject for determination the level of Follicle Stim
... Show MoreThis study included the effect of chronic exposure of different concentrations of sodium chloride on the freshwater Crustacean Daphinea pulex from the order of Cladocera. The concentrations used for the chronic exposure were( 0.1‰, 0.5‰, 1‰, 1.5‰, 2‰ )to investigate the effect on the some reproductive parameter which included mean number of eggs and juveniles produced per female and per clutch,and mean number of clutch per female which decline from (6.0) clutch/female in the control treatment to (3.0) clutch/female in (2‰) concentrations, as well as to investigate the number of females produce the clutches and we found only one female produced six cluthes in the( 2‰) concentration of sodium chlor
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