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Generation and Experimental Stress Analysis of Elliptical Gears with Combined Teeth
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In this study, generation of elliptical gears with different teeth profiles of crowned involute, double circular arc (DCA), and combined (crowned involute with DCA) has been developed. The resulting mathematical equations have been computerized and feed to CNC end mill machine to manufacture elliptical gear models with different profiles. These models are investigated in plane polariscope to show the resulting stresses under certain load. Comparison of photo-elastic stress results shows that combined elliptical gears with DCA side as a loaded side have a minimum resulting contact stress with a reduction percentage of 40% compare with contact stresses in counterpart elliptical gear of involute profile (which is commonly used in several applications). In this case, bending tooth stress reduction is 47.05% compare with involute elliptical gear. While the reduction in bending stresses of combined elliptical gear becomes higher (52.94% lower than involute gear) when crowned involute side is the loaded side, but the contact stress reduction in this case becomes lower (20% relative to involute gear). Maximum reduction in bending stress can be obtained when single profile of DCA type is used with a reduction of 64.7% relative to involute gear. Therefore; when the application requires a high contact stress resistance, combined profile can be used with DCA side as a loaded side. While in the applications that require high bending stress resistance, DCA profile can be used.

 

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Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Engineering
Buckling Analysis of Composite Plates under Thermal and Mechanical Loading
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Buckling analysis of composite laminates for critical thermal (uniform and linear) and mechanical loads is reported here. The objective of this work is to carry out theoretical investigation of buckling analysis of composite plates under thermomechanical loads, and experimental investigation under mechanical loads. The analytical investigation involved certain mathematical preliminaries, a study of equations of orthotropic elasticity for classical laminated plate theory (CLPT), higher order shear deformation plate theory (HSDT) , and numerical analysis (Finite element method), then the equation of motion are derived and solved using Navier method and Levy method for symmetric and anti-symmetric cross-ply and angle-ply laminated plates t

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Publication Date
Sat Jun 21 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The Effects of Nano-Hydroxyapatite and Casein Phosphopeptide-Amorphous Calcium Phosphate in Preventing Loss of Minerals from Teeth after Exposure to an Acidic Beverage (An In vitro Study)
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Background: To evaluate the effect of antierosive agents (10% Nano-Hydroxyapatite (NHA), 10% Casein Phophopeptide-Amorphous Calcium Phosphate (CPP-ACP), and combination of 10% NHA and 10% CPP-ACP) on loss of minerals from enamel surface of permanent teeth treated with antierosive agents when exposed to an acidic beverage and investigate the morphological changes of treated enamel surface after demineralization with cola based beverage under Scanning Electron Microscope (SEM). Materials and Methods: Sixty maxillary first premolars were randomly divided into four groups, 15 teeth for each group. Group I treated with 10% NHA, Group II treated with 10% CPP-ACP, Group III treated with 10% NHA and 10% CPP-ACP, and Group IV did not treat with any

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Publication Date
Wed Jan 10 2018
Journal Name
Al–bahith Al–a'alami
Work Stress Sources of the Communicator in Public Relations “A field study on Governmental Institutions in UAE”.
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This study addressed the work stress sources and level of the communicator in public relations in governmental institutions in the United Arab Emirates. The importance of this study is the lack of studies on work stress of the communicator in public relations. The study aimed to investigate the work stress source Physical, individual, groups, organizational and Professional source which effect on the performance of communicator in public relations. The researcher used the descriptive approach and questionnaire as an essential tool for collecting information. Some of the important results of the study are The communicator in public relations facing stress in work by 42% which affect on his performance by average level. The organizational

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Publication Date
Sat Jan 01 2022
Journal Name
Arab Journal For Plant Protection
Toxicity Stress of the Durah Power Plant Ash and its Effect on the Alga Chlorococcum humicola (Naeg) Rabenhorst 1868
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Al-Naymi, N.A.Sh., H.A.S. AL-Nuaimi and M.R. Nashaat. 2022. Toxicity Stress of the Durah Power Plant Ash and its Effect on the Alga Chlorococcum humicola (Naeg) Rabenhorst 1868. Arab Journal of Plant Protection, 40(2): 188-192. https://doi.org/10.22268/AJPP-040.2.188192 This study illustrates the acute toxic effect of ash released from Durah power plant (DPP) on the biology of the phytoplankton species Chlorococcum humicola in Iraq. The results showed that the median lethal concentration for killing 50% of the Alga population (LC50) was 0.15 and 0.13 ppt (parts per thousand) for 24 and 48 hours exposure to crude ash concentrations, respectively. In contrast, no LC50 value was recorded for 72 and 96 hrs after exposure. The reduction

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Publication Date
Fri Mar 31 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
The Effects of Melatonin On The Oxidative Stress , Protein Glycation , Microalbuminuria and Lipid Profile In Type II Diabetes Mellitus
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Previous studies indicated that supplementation with antioxidants has a protective effects against oxidative stress–induced damage in type 2 diabetes. In this study we evaluated the antioxidant effects of melatonin on the oxidative stress parameters and microalbuminuria in type 2 DM patients. 30 patients with type 2 DM were treated with 3mg/day melatonin for 90 days. Erythrocytes and plasma MDA and glutathione, fasting plasma glucose, %HbAIC, microalbuminuria, total plasma protein and lipid profile were measured each 30 days and compared with those obtained from 20 healthy controls.

A decrease in MDA levels associated with the elevation in GSH levels were observed, compared with the pre–treatment levels.

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Publication Date
Fri Oct 30 2020
Journal Name
International Journal Of Agronomy
Molybdenum Induces Growth, Yield, and Defence System Mechanisms of the Mung Bean (Vigna radiata L.) under Water Stress Conditions
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Water stress has a negative impact on the yield and growth of crops worldwide and consequently has a global impact on food security. Many biochemical changes occur in plants as a response to water stress, such as activation of antioxidant systems. Molybdenum (Mo) plays an important part in activating the expression of many enzymes, such as CAT, POD, and SOD, as well as increasing the proline content. Mo therefore supports the defence system in plants and plays an important role in the defence system of mung bean plants growing under water stress conditions. Four concentrations of Mo (0, 15, 30, and 45 mg·L−1) were applied to plants, using two approaches: (a) seed soaking and (b) foliar application. Mung bean plants were subject

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Publication Date
Thu Mar 31 2016
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study of the Performance of Compound Parabolic Concentrating Solar Collector
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The design, construction and investigation of experimental study of two compound parabolic concentrators (CPCs) with tubular absorber have been presented. The performance of CPCs have been evaluated by using outdoor experimental measurements including the instantaneous thermal efficiency. The two CPCs are tested instantly by holding them on a common structure. Many tests are conducted in the present work by truncating one of them in three different levels. For each truncation the acceptance half angle (θc) was changed. Geometrically, the acceptance half angle for standard CPC is (26o). For the truncation levels for the other CPC 1, 2 and 3 the acceptance half angle were 20o, 26o and 5

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Publication Date
Thu Feb 01 2018
Journal Name
Journal Of Engineering
Experimental Investigation of the Electro Co-deposition of (Zinc-Nickel) Alloy
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An experimental investigation has been carried out for zinc-nickel (Zn-Ni) electro-deposition using the constant applied current technique. Weight difference approach method was used to determine the cathode current efficiency and deposit thickness. Also, the influence effect of current density on the deposition process, solderability, and porosity of the plating layer in microelectronic applications were examined. The bath temperature effect on nickel composition and the form of the contract was studied using Scanning Electron Microscope (SEM). Moreover, elemental nature of the deposition was analyzed by Energy Dispersive X-Ray (EDX).     

It has been found that the best bath temperature

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Publication Date
Thu Sep 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Auto Risk Analysis in Iraq
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يتنامى يوما بعد يوم استخدام السيارات وتتعاضم اعدادها ، فهذا هو عصر السرعة، وخاصة في مجال النقل والمواصلات، والتي تتحقق باستخدام وسائل النقل المختلفة ومن بينها السيارات، وبالتالي اصبحت هذه الوسيلة ضرورية لتحقيق هذه السرعة ومن ضرورات الحياة في انجاز الاعمال.

وتتبارى مصانع السيارات فيما بينها لانتاج انواع السيارات بمواصفات عالية من المتانة والامان والراحة، وفي ذات الوقت اصبحت هندسة الطرق

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Publication Date
Mon Apr 23 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Comparative Analysis of Various Techniques for Giardia lamblia Detection and Association with E coil and Shigella Among Children Attending AL-Imamin AL-Kadhimin Medical City
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 Diarrhea is an important public health problem worldwide, several causes associated with diarrhea especially in population live under poverty and unsafe water use. Different methods are available and use in diagnosis. This study was carried out to compare of various techniques for Giardia lamblia detection and study the association with  E coil and Shigella in patients with diarrhea.  A total of 100 children with diarrhoea were enrolled into the study, 57 were males and 43 were females, aged from 2 months -16 years were attendant to AL-Imamin AL-Kadhimin Medical City, during the period from May 2014 to February 2015.  Stool samples were collected and analysed for Giardia lamblia

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