Abstract: Aluminum alloys grade 6061-T6 are characterized by their excellent properties and processing characteristics which make them ideal for varieties of industrial applications under cyclic loading, aluminum alloys show less fatigue life than steel alloys of similar strength. In the current study, a nanosecond fiber laser of maximum pulse energy up to 9.9 mJ was used to apply laser shock peening process (LSP) on aluminum thin sheets to introduce residual stresses in order to enhance fatigue life under cyclic loading Box-Behnken design (BBD) based on the design of experiments (DOE) was employed in this study for experimental design data analysis, model building and optimization The effect of working parameters spot size (ω), scanning speed (v) and pulse repetition rate (PRR) at three levels on the fatigue life expressed by the number of cycles (noc) were investigated The experimental results show an exclusive and significant percentage increase in the fatigue life of 505.25% and 477.81% when the ω= 0.04 mm and PRR= 22.5 kHz for two scanning speeds 200 mm/s and 500 mm/s respectively The optimized data extracted from the built model suggest a number of input parameters sets to enhance the performance of the process.
The A.C conductivity of three samples of lanthanide oxide : zinc oxide (La2O3)1-x(ZnO)x pellets with different zinc oxide content which were sintered 1273 K temperatures were studied using LRC meters in the frequency range of 50–106 Hz at temperature of 30 °C. The a.c conductivity, was analyzed depending of the universal power law proposed by Jonsher,. The slope of the relation between logarithm of a.c conductivity and angular frequency represent the s value were in the range (0.44-0.77) which found to increase by increasing of zinc oxide content which coincided with the small po
This study was conducted to determine the ability of water treatment system (Vortisand) to reduce some chemical and physical properties for tigris river raw water, It consisted of turbidity, electrical conductivity, pH, total hardness, calcium Hardness as well as temperature in order to determine the unit`s efficiency for reducing their concentration as compared to those in the water produced by some classical potable water projects (Dora and Wathba) in Baghdad. Samples were collected during the cold months (December 2016 and January 2017) and during the hot months (May and June 2017). The results showed that this system has the ability to reduce some properties such as turbidity, the values were 215NTU in raw water and decreased to NTU
... Show MoreThe probability is considered one of the grammatical cases in all languages of the world. Expressions of probability in Spanish language are expressed by various structures, expressions and some verb tenses. By this study explains the grammatical cases, the verbal periphrases, the impersonal expressions, the future tenses (simple and perfect) and the conditional mode of probability in Spanish language .We have explains these cases in detail with examples that have extracted from various spanish grammar books .The specific objective of this study is to know the resources and constructions of probability in Spanish language and their translation in Arabic language.
Objectives: To evaluate the effect of vitamin D3 local injections on apical root resorption, alveolar bone integrity, and chair-side time following three and six months of canine retraction. Subjects and Methods: Seventeen adult patients (18-35 years old) of class I and II malocclusions were recruited, who required bilateral maxillary 1st premolars extraction before starting maxillary canines retraction. The experimental side received 25 pg dose of vitamin D3 injected locally into the distal periodontal sulcus of the canine (before force application) every three weeks, while the control side received retraction force only. Periapical radiographic evaluation was conducted after 3 and 6 months of the start of canines' retraction. Results: At
... Show MoreBackground: Toxin-producing Shiga Escherichia coli has been identified as a new foodborne pathogen that poses a significant health risk to humans. Shiga toxin-producing Escherichia coli can be found in raw cow milk and its derivatives. A small number of Escherichia coli strains that produce shiga toxin are pathogenic. Aim of study: The study aimed to see if there were any virulence genes in 50 milk samples that were typical of Entero-haemorrhagic E. coli and evaluate the Myrtus communis effects on these bacteria. Materials and Method: Milk samples were used to isolate E. coli bacteria (n= 27), biochemically analyzed, and genetically screened for virulence genes using a multiplex (PCR). The hydro-alcoholic extraction of Myrtus communis leave
... Show MoreDiabetic mellitus is one of the main risk factors of fungal infections because poor glycemic control is associated with a high level of glucose in blood and saliva which could be treated as nutrient to fungi. This study aimed to isolate and identification of pathogenic fungi from diabetic patient. 140 samples were taken from different places of human body from the national center of diabetic patients that related to Mustansiriyah University / college of medicine and Al-yarmuk Hospital in Baghdad. 84 sample (60%) tested positive to fungi and 56 sample (40%) tested negative to fungi. The most frequented fungi isolated have been chosen for molecular identification by PCR (Millerozyma farinosa and Candida orthopsilosis) using specific pri
... Show MoreThis research aims to clarify the advantages of using the regression method as analytical procedure in the tax audit to reducing the examination cost , time, effort, human and material resources, and represents an applied study in the General Commission of taxes. In order to achieve its objectives the research has used in the theoretical side the descriptive approach (analytical), and in the practical side regression method has been applied to the research sample represented by the soft drinks company that is subject to the tax settlement for the year 2014, where the value of sales has been verified by using the regression method without conductinga comprehensive examination. The most important results of the research indicate that the r
... Show MoreThe aim of the research is to identify psychological toughness and its relationship to some coordination, physical abilities and accuracy of some basic performance skills among the players of the Iraqi junior national handball team players. The hypothesis is the existence of a correlation between psychological toughness, coordination, physical abilities, and the accuracy of some basic skills performance among the players of the Iraqi junior national handball team players. The descriptive approach in the style of correlational relations used to suit the research problem, as the community was determined by (18) players for the Iraqi junior national handball team players, while the sample was (14) players, and the samp
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