Different parameters of double pipe helical coil were investigation experimentally. Four coils were used; three with a curvature ratio (0.037, 0.031, and 0.028) and 11mm diameter of the inner tube while the fourth with 0.033 curvature ratio and 13 mm diameter of the inner tube. The hot water flow in the inner tube whereas the cold water flows in the annulus. The inlet temperatures of hot and cold water are 50 0C and 18 0C respectively. The inner mass flow rate ranges from 0.0167 to 0.0583 kg/s. The results show the Nusselt number increase with increase curvature ratio. The Nusselt number of the coil with 0.037 curvature ratio increases by approximately 12.3 % as compare with 0.028 curvature ratio. The results also r
... Show MoreWriting in English is one of the essential factors for successful EFL learning .Iraqi students at the preparatory schools encounter problems when using their background knowledge in handling subskills of writing(Burhan,2013:164).Therefore, this study aims to investigate the 4thyear preparatory school students’ problems in English composition writing, and find solutions to these pro
... Show MoreUnder-reamed piles defined by having one or more bulbs have the potential for sizeable major sides over conventional straight-sided piles, most of the studies on under-reamed piles have been conducted on the experimental side, while theoretical studies, such as the finite element method, have been mainly confined to conventional straight-sided piles. On the other hand, although several laboratory and experimental studies have been conducted to study the behavior of under-reamed piles, few numerical studies have been carried out to simulate the piles' performance. In addition, there is no research to compare and evaluate the behavior of these piles under dynamic loading. Therefore, this study aimed to numerically investigate bearing capaci
... Show Moreأجريت هذه الدراسة في محافظة النجف بالعراق لتحليل عينات بيولوجية من المدخنين وغير المدخنين. تم استخدام العينات، بما في ذلك مصل الدم والبول والشعر والأظافر، كمؤشرات حيوية لتحديد تركيزات اليورانيوم (UC) ونظائره (238U، 235U، و234U). وباستخدام طريقة التعرض الطبيعي، تم استخدام كاشف المسار النووي (CR-39، المملكة المتحدة) لقياس تركيزات اليورانيوم في العينات. تم جمع خمسة وسبعين عينة من مصل الدم والبول والشعر والأظافر للمد
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The multiple linear regression model of the important regression models used in the analysis for different fields of science Such as business, economics, medicine and social sciences high in data has undesirable effects on analysis results . The multicollinearity is a major problem in multiple linear regression. In its simplest state, it leads to the departure of the model parameter that is capable of its scientific properties, Also there is an important problem in regression analysis is the presence of high leverage points in the data have undesirable effects on the results of the analysis , In this research , we present some of
... Show MoreThis research examines the use of time in Hebrew children's literature and how historical narratives about the biblical period and beyond formed an arena for narrative conflict between the 1960s and the mid-1980s. The research clarifies the nature of narrative time: the time of events within the story itself (the sequence of events، the rhythm، and the occasional shifts between past and present)، as well as the framing time، which is the historical period the narrator perceives as the backdrop to the narrative. It also explores the time of memory and the use of flashbacks، evocations، or temporal allusions that connect young readers to a collective past. Our research also addresses how Zionist narratives began to lose credibility afte
... Show MoreDegenerate parabolic partial differential equations (PDEs) with vanishing or unbounded leading coefficient make the PDE non-uniformly parabolic, and new theories need to be developed in the context of practical applications of such rather unstudied mathematical models arising in porous media, population dynamics, financial mathematics, etc. With this new challenge in mind, this paper considers investigating newly formulated direct and inverse problems associated with non-uniform parabolic PDEs where the leading space- and time-dependent coefficient is allowed to vanish on a non-empty, but zero measure, kernel set. In the context of inverse analysis, we consider the linear but ill-pose