This paper presents a comparison study on thermal performance conic cut twist tape inserts in laminar flow of nanofluids through a constant heat fluxed tube. Three tape configurations, namely, quadrant cut twisted tape (QCT), parabolic half cut twisted tape (PCT), and triangular cut twisted (VCT) of twist ratio= 2.93 and cut depth= 0.5 cm were used with 1% and 2% volume concentration of SiO2/water and TiO2/water nanofluids. Typical twist tape with twist ratio of= 2.93 was used for comparison. The results show that the heat transfer was enhanced by increasing of Reynolds number and nanoparticles concentration of nanofluid. The results have also revealed that the use of twist tape enhanced the heat transfer coefficient significantly and maximum heat transfer enhancement was achieved by the presence of triangular cut twist tape insert with 2% volume concentration of SiO2nanofluid. Over the range investigated, the maximum thermal performance factor of 5.13 is found with the simultaneous use of the SiO2nanofluid at 2% volume concentration VCT at Reynolds number of 220. Furthermore, new empirical correlations for Nusselt number, friction factor, and thermal performance factor are developed and reported.
In this paper, a new technique is offered for solving three types of linear integral equations of the 2nd kind including Volterra-Fredholm integral equations (LVFIE) (as a general case), Volterra integral equations (LVIE) and Fredholm integral equations (LFIE) (as special cases). The new technique depends on approximating the solution to a polynomial of degree and therefore reducing the problem to a linear programming problem(LPP), which will be solved to find the approximate solution of LVFIE. Moreover, quadrature methods including trapezoidal rule (TR), Simpson 1/3 rule (SR), Boole rule (BR), and Romberg integration formula (RI) are used to approximate the integrals that exist in LVFIE. Also, a comparison between those
... Show MoreThe increase in the number of trucks and other heavy vehicles in Iraqi highways lead to cracking and deteriorations in the flexible highway. The use of polymermodified asphalt may solve this problem to match the required performance standards. This study investigates the effects of styrene-butadiene-styrene (SBS) polymer on the performance behaviour of Iraqi bitumen binder. The characteristics of bitumen binder were analysed to observe the compatibility of bitumen with SBS polymer. The bitumen binder was mixed with three different contents of SBS (4%, 4.5%, and 5%) by weight of asphalt cement. Viscosity tests were conducted on the SBS polymer-modified asphalt at 135 oC and 165 oC in addition to conventional binder tests. The prepar
... Show MoreDespite the significant increase in women in academic medicine over the last 50 years, women are still under-represented in leadership positions in academia. However, there is a lack of data on the diversity of editorial boards in Middle Eastern medical journals. So, we aim to portray the diversity of editorial boards of Iraqi medical journals by conducting a cross-sectional analysis of the editorial boards’ members of all Iraqi medical journals. Gender, affiliation and specialty were extracted from the journals’ websites and/or from the professional profiles of the editorial board members. Twenty-five journals and 446 editorial board members were analysed. More than half of editorial board members specialized in basic scienc
... Show MoreThis paper analyzes a piled-raft foundation on non-homogeneous soils with variable layer depth percentages. The present work aims to perform a three-dimensional finite element analysis of a piled-raft foundation subjected to vertical load using the PLAXIS 3D software. Parametric analysis was carried out to determine the effect of soil type and initial layer thickness. The parametric study showed that increasing the relative density from 30 % to 80 % of the upper sand layer and the thickness of the first layer has led to an increase in the ultimate load and a decrease in the settlement of piled raft foundations for the cases of sand over weak soil. In clay over weak soil, the ultimate load of the piled raft foundation w
... Show MoreIn this paper, a new technique is offered for solving three types of linear integral equations of the 2nd kind including Volterra-Fredholm integral equations (LVFIE) (as a general case), Volterra integral equations (LVIE) and Fredholm integral equations (LFIE) (as special cases). The new technique depends on approximating the solution to a polynomial of degree and therefore reducing the problem to a linear programming problem(LPP), which will be solved to find the approximate solution of LVFIE. Moreover, quadrature methods including trapezoidal rule (TR), Simpson 1/3 rule (SR), Boole rule (BR), and Romberg integration formula (RI) are used to approximate the integrals that exist in LVFIE. Also, a comparison between those methods is
... Show MoreThe European continent suffers from the presence of some separatist tendencies, as it becomes clear the impact of racial and ethnic variables driving towards the crystallization of separatist conflicts that led to the success of some of them in the establishment of sovereign states, while the other failed to achieve this, the research focused on the importance of matching geographical, cultural and political criteria In the success of separatist trends, he also focused on the role of the policies imposed by the mother state in curbing or exacerbating the separatist trend through the level of justice in the distribution of wealth between the regions, and what are the rights and duties of those oppressed and abused minorities, so the r
... Show MoreThis study offers additional evidence for the occurrence of oil residues within fractures of the basement rocks in the Upper Benue Trough, Nigeria. The data suggests that the observed oil residues were originally generated as light oils, which were later biodegraded into heavy oils. These Upper Benue Trough's oil stains are a valuable tool for hydrocarbon exploration in the region as they indicate the existence of a petroleum system in the basin. We find a strong similarity to the proportions of C27, C28, and C29 regular steranes of oils found in the sandstones and shales of the Bima Formation in the Upper Benue Trough when we plot the relative quantities of these steranes of the investigated basement rock oil types on a ternary gra
... Show MorePrecise and interpretable classification of autism-related behaviors is important for initial diagnosis, personalized intervention, and support arrangements. This study proposes an interpretable machine learning (ML) model using Light Gradient Boosting Machine (LightGBM) and Categorical Boosting (CatBoost) to classify behavioral patterns into four categories (normal, mild, moderate, and severe) associated with Autism Spectrum Disorder (ASD) based on a custom 377-instance survey dataset from Iraqi parents and teachers of children aged 6-12. The model observes 16 key features across communication and social interaction, repetitive behaviors, language, and adaptive skills, preprocessed via interquartile range (IQR) outlier removal, me
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