Fatigue failure is almost considered as the predominant problem affecting automotive parts under dynamic loading condition. Thus, more understanding of crack behavior during fatigue can strongly help in finding the proper mechanism to avoid the final fracture and extent the service life of components. The main goal of this paper is to study the fracture behavior of low carbon steel which is used mostly in automotive industry. For this purpose, the fractography of samples subjected to high and low stress levels in fatigue test then was evaluated and analyzed. Hardness and tensile tests were carried out to determine the properties of used steel. Also, the samples were characterized by microstructure test and XRD analysis to examine the constitute phases. The fatigue test (S-N curve) was done at stress ratio (R= -1), and the fracture examination was perform using Scanning Electron Microscope (SEM). The results of microstructure and XRD analysis were indicating that the Ferrite and a little amount of pearlite are the dominant phases of this steel. Whereas, the fractography observations reveal that the void coalescence ductile fracture is the main failure mode in samples with high stress level, while the ductile fracture (void coalescence) with Transgranular Cleavage fracture was noticed in low stress fatigue mode for this alloy.
على الرغم من تطور الدراسات التاريخية الخاصة بالمرأة بوصفها حقل معرفي مستقل بدأ منذ نهاية الستينيات من القرن الماضي .ونجاج الكاتبات والباحثات في العديد من بلدان الشرق الاوسط وشمال افريقيا في إعادة المرأة الى التاريخ، الا ان الكتابة التاريخية في العراق مازالت تعاني من نقص كبير في الموضوعات التي تناولت حياة النساء في الماضي. وما يزال الباحثات والباحثين ينظرون الى التاريخ على انه سردية للمعارك والحروب ويو
... Show MoreThis study aims to find out the impact of activities office provided to kindergarten children in the development of creativity in linguistic performance goal of capabilities (fluency, flexibility and originality) through the application of the test configuration Algheih Children Riyadh, which consists of (70) Single to measure the skills of language arts four a listening and speaking and a willingness to read and prepare for writing, was applied (30) Single of language arts, listening and speaking in this research, and was the correlation coefficient for the hearing (0.78) and for speaking was (0.61) has been extracted stability of the scale using the equation Alvakronbach the value of (0.73).
The proper
... Show Moreالمقدمة ومنهجية البحث
تتفق أغلب الأدبيات ومنها المحاسبية, بأن الخطوة الأولى في وضع وتقييم أي نظام إداري أو محاسبي هي في صياغة أهداف ذلك النظام لما لذلك من أهمية في توفير معيار للحكم على كفاءة التطبيق من عدمه.
وتعرف الأهداف بأنها (النهايات التي تعمل أو توجه النشاطات باتجاهها أو هي النهايات التي تطمح النشاطات تحقيقها). ( 1 ) ..,
كما تعرف أيضا بأنها (الأ
... Show Moreالملخص:- يهدف البحث الى معرفة اثر استراتيجية المنطقة ذات الاهمية في تحصيل مادة الكيمياء عند طالبات الصف الثاني المتوسط، ولتحقيق هدف البحث تم صياغة الفرضية الصفرية الاتية :- - لا يوجد فرق ذو دلالة احصائية عند مستوى دلالة (0.05 ) بين متوسط درجات طالبات المجموعة التجريبية اللاتي يدرسن وفقا لاستراتيجية المنطقة ذات الاهمية ومتوسط درجات طالبات المجموعة الضابطة اللاتي يدرسن وفق الطريقة الاعتيادية في تحصيل مادة الكيمي
... Show MoreIn this paper, we will illustrate a gamma regression model assuming that the dependent variable (Y) is a gamma distribution and that it's mean ( ) is related through a linear predictor with link function which is identity link function g(μ) = μ. It also contains the shape parameter which is not constant and depends on the linear predictor and with link function which is the log link and we will estimate the parameters of gamma regression by using two estimation methods which are The Maximum Likelihood and the Bayesian and a comparison between these methods by using the standard comparison of average squares of error (MSE), where the two methods were applied to real da
... Show MoreAn abstract is a brief summary of a research article, thesis, Schiff base ligand (L) was prepared by the reaction of 4-aminantipyrine with o-phenylenediamine, the prepared ligand characterized by Micro elemental Analysis, FT. IR, UV-Vis, and 1H,13C-NMR spectroscopy.complexes of Mn(II), Co(II), Ni(II), Cu(II) and Hg(II) with Schiff base and 1,10-phenanthroline (Phen) have been investigated in aqueous ethanol with (1:1:1) (M:L:Phen). The prepared complexes were characterized using flame atomic absorption, (C. H. N) Analysis, FT. IR and UV-Vis spectroscopic methods as well as magnetic susceptibility and conductivity measurements. From the obtained data the octahedral structure was suggested for all complexes. The biological screening effects o
... Show MoreThe new Hexadentate complexes type [M(H3L3)]K were prepared from the condensation reaction of Diphenylmonoxime and KOH with (Mn(II), Co(II), Ni(II), Cu(II), Zn(II), and Hg(II)) in methanol with 3:1 ligand : metal ratio to give a series of new complexes of the general formula [M(H3L3)]K (where: M(II) = Mn ,Co ,N ,Cu ,Zn and Hg).All compounds have been Characterized by spectroscopic methods [I.R, U.v-Vis, atomic absorption and microanalysis (C.H.N) along with conductivity measurements. The stability constant K and Gibbs free energy ∆G were calculated for [Co (H3L3)] K, [Ni (H3L3)] K and [Cu (H3L3)] K and complexes using spectrophotometer method. The obtained values indicate that these complexes stable in their solution. From the above data
... Show MoreThe Co (II), Ni (II) ,Cu(II), Zn(II) ,Cd(II) and Hg(II) complexes of mixed of amino acid (L-Alanine ) and Trimethoprim antibiotic were synthesized. The complexes were characterized using melting point, conductivity measurement and determination the percentage of the metal in the complexes by flame (AAS). Magnetic susceptibility, Spectroscopic Method [FTIR and UV-Vis]. The general formula have been given for the prepared mixed ligand complexes [M(Ala)2(TMP)(H2O)] where L- alanine (abbreviated as (Ala ) = (C5H9NO2) deprotonated primary ligand, L- Alanine ion .= (C5H8NO2 -) Trimethoprim (abbreviated as (TMP ) = C10H11N3O3S M(II) = Co (II),Ni(II) ,Cu(II), Zn(II) ,Cd(II) and Hg(II). The results showed that the deprotonated L- Alanine by KOH (Ala
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