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Stress Concentration factor Analysis of Helical Gear Drives with Asymmetric Teeth Profiles
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This study investigates the influence of asymmetric involute teeth profiles for helical gears on the bending stress. Theoretically, bending stress has been estimated in spur involute gears which have symmetric teeth profile by based on the Lewis, 1892 equation. Later, this equation is developed by, Abdullah, 2012. to determine the effect of an asymmetric tooth profile for the spur gear on the bending stress. And then these equations are applied with stress concentration factor once for symmetric and once other for asymmetric teeth profile. In this paper, the bending stresses for various types of helical gear with various types of asymmetric teeth profile are calculated numerically for defined the stress concentration factor. The numerical solution based on the finite element method technique which that done by using the software simulation SolidWorks 2016. The results of this study indicate that the helical gear drive with asymmetric teeth profile having 'loaded side pressure angle' of ( ) and 'unloaded side pressure angle' of ( ) is better than a helical gear with standard teeth profile having pressure angle of ( ) from the regarding of tooth bending strength. Also, notes that the great enhancement in the results of maximum tooth bending stress for modified involute of tooth profile compared with the standard teeth profile. In addition to, predict the equation of stress concentration factor which is a function of both unloaded side pressure angle and helix angle and then it used with Abdullah equation for to determine the nominal stresses in the root fillet.

 

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Publication Date
Thu Jun 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Fracture Resistance of Endodontically Treated Premolar Teeth with Extensive MOD Cavities Restored with Different Bulk Fill Composite Restorations (An In vitro Study)
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Background: The present in-vitro study was undertaken to evaluate and compare fracture resistance of weakened endodontically treated premolars with class II MOD cavities restored with different bulk fill composite restorations (EverX posterior, Alert, Tetric EvoCeram Bulk Fill, and SDR). The type and mode of fracture were also assessed for all the experimental groups. Materials and Method: Forty-eight human adult maxillary premolar teeth were selected for this study. Standardized extensive class II MOD cavities with endodontic treatment were prepared for all teeth, except those that were saved as intact control. The teeth were divided into six groups of eight teeth each (n=8): (Group 1) intact control group, (Group 2) unrestored teeth with

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Publication Date
Sun May 12 2019
Journal Name
Oral And Maxillofacial Surgery
Lingual anesthesia of the lower anterior teeth, which technique is better?
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Purpose To extract the lower anterior teeth, the oral surgeon needs to anesthetize the pulpal tissue of the accused tooth and the surrounding tissues. The lingual nerve innervates the lingual soft tissue to the lower teeth, this nerve usually anesthetized alongside the inferior alveolar nerve by a block technique. However, the lingual tissue of the lower anterior teeth usually anesthetized by either infiltration or periodontal ligament injection (PDL) techniques. This study was intended to compare between these two techniques. Methods Forty-eight teeth were extracted from 24 patients. Non-adjacent two lower anterior teeth in the same patient were selected. The lingual soft tissue in one of them was anesthetized by PDL injection technique wh

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Publication Date
Thu Oct 15 2015
Journal Name
International Journal Of Computer Applications
Experimental Investigation for Small Horizontal Portable Wind Turbine of Different Blades Profiles under Laboratory Conditions
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Experimental investigation for small horizontal portable wind turbine (SHPWT) of NACA-44, BP-44, and NACA-63, BP-63 profiles under laboratory conditions at different wind velocity range of (3.7-5.8 m/s) achieved in present work. Experimental data tabulated for 2, 3, 4, and 6- bladed rotor of both profiles within range of blade pitch angles . A mathematical model formulated and computer Code for MATLAB software developed. The least-squares regression is used to fit experimental data. As the majority of previous works have been presented for large scale wind turbines, the aims were to present the performance of (SHPWT) and also to make a comparisons between both profiles to conclude which is the best performance. The overall efficiency and el

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Publication Date
Tue Jan 24 2023
Journal Name
Euphrates Journal Of Agricultural Science
PCR-RFLP Analysis of Insulin-Like Growth Factor 2 Gene Polymorphisms in Two Commercial Broiler Chicken Strains (Cobb 500 and Hubbard F-15) and Their Associations with Performance Traits
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In two commercial broiler breeds (Cobb 500 and Hubbard F-15), the polymorphisms of the chicken insulin-like growth factor 2 (IGF2) gene were studied. A total of three hundred avian blood samples were obtained. Using a fast salt-extraction technique, genomic DNA was isolated. Using polymerase chain reaction, 1146 bp fragments of the gene were amplified (PCR). The amplified fragments were subjected to restriction enzyme digestion using HinfI endonuclease enzyme, and the digested products were separated on a 2% agarose gel. The findings indicated two alleles T and C for the target locus, with respective frequencies of 73.3% and 26.7%. Three distinct genotype variations, TT, TC, and CC, were found, with genotype frequencies of 59.1 percent, 28.

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Humoral immune factor changes in group of patients with Non-muscle invasive bladder cancer treated with intravesical therapy.
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Publication Date
Tue Jan 01 2013
Journal Name
Advances In Physics Theories And Applications
Tracing and Analysis of Manganese, Nickel, Cadmium ,Copper, zinc , Lead And Aluminum Concentration and PH Values In Iraqi Chewing Gums
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Evaluation of trace elements in Iraqi chewing gums are unavailable, particularly pollution of toxic elements, materials which change the values of PH in the Oral. Atomic Absorption Spectroscopy (AAS) were successfully employed to determine the concentration of 7 trace elements (essentially toxic and nonessential) and the PH, in thirteen different brands of chewing gum generally consumed in Iraq. Combined wet and dry digestion procedures were applied. Two types of heated graphite tubes were used, coated and uncoated tubes treated with tungsten solution. Result showed that Cu, Al and Zn were at very high levels in almost all brands whereas Mn was found to be high in brands A and O only.

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Publication Date
Wed Mar 18 2020
Journal Name
Baghdad Science Journal
Lemon juice antioxidant activity against oxidative stress
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This study is conducted to evaluate the therapeutic and antioxidant effect of lemon juice on some hematological and biochemical parameters. Thirty female mice used in this study were exposed to oxidative stress through giving them hydrogen peroxide in drinking water for 30 days. Animals randomly distributed over 3 groups, each group contained 10 animals and treated as follows: T1 control group (drinking distilled water only), T2 (0.75% hydrogen peroxide in drinking water) and T3 (0.75% hydrogen peroxide in drinking water with daily drenching with 1 mL lemon juice). At the end of the experiment, blood samples were collected from animals for evaluating the following hematological and biochemical parameters: Haemoglobin concentration (Hb),

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Publication Date
Tue Aug 03 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Structural Equation Modeling for Tourist Attraction Factors in Asir Region by Using Factor Analysis in the Light of Vision of kingdom of Saudi Arabia (KSA) 2030
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The research aimed to modeling a structural equation for tourist attraction factors in Asir Region. The research population is the people in the region, and a simple random sample of 332 individuals were selected. The factor analysis as a reliable statistical method in this phenomenon was used to modeling and testing the structural model of tourism, and analyzing the data by using SPSS and AMOS statistical computerized programs. The study reached a number of results, the most important of them are: the tourist attraction factors model consists of five factors which explain 69.3% of the total variance. These are: the provision of tourist services, social and historic factors, mountains, weather and natural parks. And the differenc

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Publication Date
Sat Dec 31 2016
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
The Effect of In-situ Stress on Hydraulic Fractures Dimensions
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Understanding of in-situ stress profiles and orientations plays a vital role in designing a successful hydraulic fracturing treatment. This paper is an attempet to examine the effect of lithology and in situ stress on geometery of hydraulic fractures. A hydraulic fracturing design simulator software called FracproPT with various capabilities for designing most of hydraulic fracture was used for  simulate and optimize the hydraulic fracturing. For studying purpose,  three different cases of stress gradient contrast between different formations  are considered in this study (0.4, 0.5 and 0.75 psi/ft). The results obtained from the simulator showed that  lithologies surrounding the pay zone have an effect on the fracture

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Publication Date
Sat Jun 07 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of surface treatments and thermocycling on shear bond strength of various artificial teeth with different denture base materials
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Background: Separation and deboning of artificial teeth from denture bases present a major clinical and labortory problem which affect both the patient and the dentist. The optimal bond strength of artificial teeth with denture base reinforced with nanofillers and flexible denture bases and the effect of thermo cycling should be evaluated. This study was conducted to evaluate and compare the shear bond strength of artificial teeth (acrylic and porcelain) with denture bases reinforced by 5% Zirconium oxide nanofillers and flexible bases under the effect of different surface treatments and thermo cycling and comparing the results with conventional water bath cured denture bases. Material and methods: Two types of artificial teeth; acrylic and

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