Theoretical and experimental investigations have been carried out on developing laminar
combined free and forced convection heat transfer in a vertical concentric annulus with uniformly
heated outer cylinder (constant heat flux) and adiabatic inner cylinder for both aiding and opposing
flows. The theoretical investigation involved a mathematical modeling and numerical solution for
two dimensional, symmetric, simultaneously developing laminar air flows was achieved. The
governing equations of motion (continuity, momentum and energy) are solved by using implicit
finite difference method and the Gauss elimination technique. The theoretical work covers heat flux
range from (200 to 1500) W/m2, Re range from 400 to 2000 an
It is commonly known that Euler-Bernoulli’s thin beam theorem is not applicable whenever a nonlinear distribution of strain/stress occurs, such as in deep beams, or the stress distribution is discontinuous. In order to design the members experiencing such distorted stress regions, the Strut-and-Tie Model (STM) could be utilized. In this paper, experimental investigation of STM technique for three identical small-scale deep beams was conducted. The beams were simply supported and loaded statically with a concentrated load at the mid span of the beams. These deep beams had two symmetrical openings near the application point of loading. Both the deep beam, where the stress distribution cannot be assumed linear, and the ex
... Show MoreThe pilgrimage takes place in several countries around the world. The pilgrimage includes the simultaneous movement of a huge crowd of pilgrims which leads to many challenges for the pilgrimage authorities to track, monitor, and manage the crowd to minimize the chance of overcrowding’s accidents. Therefore, there is a need for an efficient monitoring and tracking system for pilgrims. This paper proposes powerful pilgrims tracking and monitoring system based on three Internet of Things (IoT) technologies; namely: Radio Frequency Identification (RFID), ZigBee, and Internet Protocol version 6 (IPv6). In addition, it requires low-cost, low-power-consumption implementation. The proposed
In oil and gas well cementing, a strong cement sheath is wanted to insure long-term safety of the wells. Successful completion of cementing job has become more complex, as drilling is being done in highly deviated and high pressure-high temperature wells. Use of nano materials in enhanced oil recovery, drilling fluid, oil well cementing and other applications is being investigated. This study is an attempt to investigate the effect of nano materials on oil well cement properties. Two types of nano materials were investigated, which are Nano silica (>40 nm) and Nano Alumina (80 nm) and high sulfate-resistant glass G cement is used. The investigated properties of oil well cement included compressive strength, thickening
... Show MoreSolar distillers are a sustainable and simple solution for addressing water scarcity, but their limited productivity restricts their effectiveness. This work aimed to assess the thermal performance of a novel tracked, tilted, hexagonal tubular solar still (HTSS) of four-sectioned U-channel receiver. Two identical HTSSs were side-to-side tested in Baghdad-Iraq (33.3°N, 43.3°E) from June to September 2024. The thermal evaluation of single-axis tracking solar still, tilted at (5° to 15°) with the horizontal axis and charged with and without hydrogel beads for water depth of 60 mm. The still's thermal performance is assessed by analyzing heat transfer coefficients, energy and exergy efficiencies, as well as conducting cost and environment
... Show MoreA field study aimed at identifying the degree of satisfaction of secondary school principals with regard to the role of universities and their obstacles in developing their administrative skills. It adopted the descriptive analytical approach. The research community consisted of (249) male and female principals in the schools of Baghdad (Al-Rusafa and Karkh), and the research sample was chosen by the simple random stratified method at a percentage of (40%) of the research community, and the number of the sample was (100) male and female principals. A questionnaire consisting of (40) items distributed between two domains was developed. Its validity and reliability were confirmed. The researcher used the (SPS
... Show MoreABSTRACT: BACKGROUND: Infantile haemangioma one of the most common tumour of new borns , a safe and effective treatment options are under ongoing research . OBJECTIVE: The authors show the effectiveness and safety of low dose propranolol as a method for infantile haemangioma treatment . METHOD: In this study twenty- four patients with infantile haemangioma in different anatomical locations were treated with oral propranolol and the result were assessed in a retrospective analysis of the results patients were kept on 0.25 mg/kg/day for one month , then on 0.5mg/kg/day in 2 divided doses for another one month , in the third month the dose will be increased to 1 mg/kg/day in 2 divided doses , then the propranolol were given in a maintenance do
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