Hand-lay up method was used to prepare the samples made of epoxy (EP) as a matrix reinforced with chopped carbon fibers (CCF). The fatigue behavior of epoxy resin /chopped carbon fiber composites was studied with different weight percentage of chopped carbon fibers (2.5%,5%,7.5%,10%,12.5%). The fatigue test was carried out under alternate bending method, which was made by applying sinusoidal wave with constant displacement (15mm), stress ratio R=-1,and loading frequency 10Hz, which is believed to give a negligible temperature rise during the test. The results of the maximum stress, fatigue strength, fatigue limit and fatigue life of the tested composites are calculated from stress(S)-number of cycles(N) (S-N) curves.
It was shown that

The aim of this research is to diagnose the attention deficit hyperactivity disorder among primary school pupils in Baquba city of Diyala province. The sample of the study consisted of (25) male and female pupils. The American Guide of Attention Deficit Hyperactivity Scale (DSM-IV, 1994) was used in this study in addition to Conner’s (1996) scale to measure the attention deficit hyperactivity disorder for teachers and parents. The result revealed that (19) male and female pupils diagnosed with attention deficit hyperactivity to various degrees.

Tremendous efforts have been exerted to understand first language acquisition to facilitate second language learning. The problem lies in the difficulty of mastering English language and adapting a theory that helps in overcoming the difficulties facing students. This study aims to apply Thomasello's theory of language mastery through usage. It assumes that adults can learn faster than children and can learn the language separately, and far from academic education. Tomasello (2003) studied the stages of language acquisition for children, and developed his theory accordingly. Some studies, such as: (Ghalebi and Sadighi, 2015, Arvidsson, 2019; Munoz, 2019; Verspoor and Hong, 2013) used this theory when examining language acquisition. Thus,

Recycling process presents a sustainable pavement by using the old materials that could be milled, mixed with virgin materials and recycling agents to produce recycled mixtures. The objective of this study is to evaluate the impact of water on recycled asphalt concrete mixtures, and the effect of the inclusion of old materials into recycled mixtures on the resistance of water damage. A total of 54 Marshall Specimens and 54 compressive strength specimens of (virgin, recycled, and aged asphalt concrete mixtures) had been prepared, and subjected to Tensile Strength Ratio test, and Index of Retained Strength test. Four types of recycling agents (used oil, oil + crumb rubber, soft grade asphalt cement, and asphalt cement + Su

Abstract

       The current study was carried out to reveal the plasma parameters such as ,the electron temperature ( ), electron density (n_e) , plasma frequency (fp), Debye length ( ) , Debye number (   for  CdS to employ the LIBS for the purpose of analyzing and determining spectral emission lines using . The results of electron temperature for CdS range (0.746-0.856) eV , the electron density(3.909-4.691)×10¹⁸ cm^-3. Finally ,we discuss plasma parameters of CdS  through  nano second  laser generated plasma .

The world is confronted with the twin crisis of fossil fuel depletion and environmental degradation caused by fossil fuel usage. Biodiesel produced from renewable feedstocks such as Jatropha seed oil or animal fats by transesterification offers a solution. Although biodiesel has been produced from various vegetable oils such as Jatropha seed oil, the reaction kinetics studies are very few in literature, hence the need for this study. Jatropha curcas seed oil was extracted and analyzed to determine its free fatty acid and fatty acid composition. The oil was transesterified with methanol at a molar ratio of methanol to oil 8:1, using 1% sodium hydroxide catalyst, at different temperature

Spider veins are a common aesthetic problem mainly in females , the conventional method of treatment is by microsclerotherapy (injections) but laser therapy has become increasingly efficacious and a convenient method for treatment. The present study was performed to investigate the effectiveness and safety of pulsed diode laser (810nm) by doing thermal photocoagulation. Ten patients with lower limbs spider veins were included in this prospective study. They were treated with a repetitive pulsed diode laser in non contact technique using the following laser parameters (wave length 810nm,power 1 W ,pulse duration 0.1 s., pulse interval 0.5 s, spot diameter 4mm ,power density 7.9 W/cm2). Laser therapy was performed on day zero and day fourt

The study is devoted to both static and earthquake response analysis of retaining structures acted upon by lateral earth pressure. Two main approaches were implemented in the analysis, namely, the Mononobe-Okabe analytical method and the numerical Finite element procedure as provided in the ready software ABAQUS with explicit dynamic method. A basic case study considered in the present work is the bridge approach retaining walls as a part of AL-Jadiriya bridge intersection to obtain the effects of the backfill and the ground water on the retaining wall response including displacement of the retaining structure in addition to the behavior of the fill material. Parametric studies were carried out to evaluate the effects of several factors

This work was conducted to study the effect of selective adsorption on removal of sulfur  compounds  from  Iraqi  heavy  naphtha  from  Al-Dura refinery  by using  molecular  sieve (13X)  in a fixed-bed column and  it was be run out at 1.5–6.0h-1 LHSV, 15–30 gr  weight of molecular sieve (13X), 600–1650ppm sulfur concentration in the feedstock ,  the adsorption  temperature  was  25oC and 40oC.  The best operating conditions for removing sulfur compounds was 3.0 h-1 LHSV, 20 gr molecular sieve bed weight and 25oC temperature, where the sulfur content in heavy naphtha was reduced from nearly 600 ppm to less than 1 ppm (by weight). Regeneration steps was thermally took place by hot air flow in a range from 16.6