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).
This research dealt with study of cladistics taxonomy of five species related to the genus Rumex L. and Polygonum L. from family polygonaceae in Iraq by using Mesquite software V.2.75. This research support strongly delimiting the species P. aviculare L. and P. lapathifolia L.as suggested in floras publication while R. dentatus L. is setted in single group whereas R. vesicarius L. and R. conglomeratus Murray were included in the same group. Also, this study involved characteristics of shape, dimensions, color, and ornamentation of seeds and fruits as the seed forms were ranging from lenticular to trigonous. In terms of size calculations, the seeds of R. vesicarius was recorded the higher range (4.0- 4.5) mm in length w
... Show MoreAbstract Exotoxin A is the most lethal virulence factor produced by Pseudomonas aeruginosa. It inhibits elongation factor-2 by ADP-ribosylation of EF2. This causes stop of the elongation of polypeptides. In recent study, the effect of low concentration of exotoxin A on some important internal organs of mice was studied. Four groups white mice were injected intraperitonialy with pure exotoxin A in the following manner 0.1, 0.2, 0.3, 0.4 ng\ animals. One mouse receives normal saline inrtaperitonialy as a control. After 72 hours the mice were killed and four organs were taken, liver, spleen, lung and heart from each killed mice. Histological sections were made from each organ and stained with hematoxylin and eosin stain then examined under mic
... Show MoreOptimization is essentially the art, science and mathematics of choosing the best among a given set of finite or infinite alternatives. Though currently optimization is an interdisciplinary subject cutting through the boundaries of mathematics, economics, engineering, natural sciences, and many other fields of human Endeavour it had its root in antiquity. In modern day language the problem mathematically is as follows - Among all closed curves of a given length find the one that closes maximum area. This is called the Isoperimetric problem. This problem is now mentioned in a regular fashion in any course in the Calculus of Variations. However, most problems of antiquity came from geometry and since there were no general methods to solve suc
... Show MoreDictyostelium discoideum amoeba is a powerful system to study gene function through genetic and functional analysis. Paracaspase (Pcp) is a caspase-like protein that has recently identified in D. discoideum. Study paracaspase molecular function in Dictyostelium will provide insight into its cellular role in more complex organisms and the possibility to use it as a drug target against the parasitic amoeba. In this study, pcp was tagged with Green Fluorescent Protein (GFP) and over-expressed in the cell. The knockout version of pcp (pcp-) was also investigated. In the course of our examination, it was observed that cells overexpress Pcp was unable to complete the developmental process, leading us to examine its role in development. Those c
... Show MoreThe parasite tapeworm (Raillietina echinobothrida) belonges to the class Cestoda, it is responsible for nodular tapeworm disease in poultry .The aim of this study was to determine tapeworm parasites infections in Columba livia from two markets in the province of Baghdad for the period from May to December 2014. From a total of thirty five sample of Columba livia were randomly selected and then examined the elementary canal of these samples. The present study showed that the collected rock pigeon were found six infected with the cestode Raillietina echinobothrida with infection rate (17.14%). The statistical analysis for the characters of the cestode showed significant differences in all recipes, but there were no significant difference
... Show MoreThe microstructures of rapidly solidified laser clad layers of laser cladding of Inconel 617 with different nickel-aluminum premixed clad powders are discussed. The effect of different cladding speeds on the microstructures of rapidly solidified laser clad layers is discussed too. The detailed microstructural results showed that different growth mechanisms are produced during rapid solidification. These are planar, cellular, cellular/dendritic and dendritic.
Neutron differential-elastic and inelastic scattering cross-sections of Yttrium-89 isotope were calculated at energies 8,10,12,14, and 17 MeV, at angles distributed between 20o and 180o in the center of mass frame. The obtained results data were interpreted using a spherical optical potential model and Eikonal approximation, to examine the effect of the first-order Eikonal correction on the effective potential. The real and imaginary parts of optical potential were calculated. It was found that the nominal imaginary potential increase monotonically while the effective imaginary one has a pronounced minimum around r = 6fm and then increases. The analysis of the relative energy of the projectile and reaction
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