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Enhancement of Heat Exchanger Performance by Using Dimpled Tube
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The enhancement of heat exchanger performance was investigated using dimpled tubes tested at different Reynolds numbers, in the present work four types of dimpled tubes with a specified configuration manufactured, tested and then compared performance with the smooth tube and other passive techniques performance. Two dimpled arrangements along the tube were investigated, these are inline and staggered at constant pitch ratio X/d=4, the test results showed that Nusselts number (heat transfer) of the staggered array is higher than the inline array by 13%.  The effect of different depths of the dimple (14.5 mm and 18.5 mm) has been also investigated; a tube with large dimple diameter enhanced the Nusselts number by about 25% for the range of Reynolds number between 4000- 20000. The overall enhancement ratio was used to differentiate the passive technique and comparison of different configurations for the technique itself, the result depicted that the 10 mm dimple diameter with a pitch ratio of X/d= 4 gives better performance than the static mixer and twisted tape techniques. The overall enhancement ratio of the 10 mm dimple diameter is varied from (1.21 to 1.65) that means good performance for a range of Reynolds numbers (4000-20000). This indicates that 21- 65 % of heat transfer area can be saved at the same pumping power compared with the smooth tube heat exchanger. 

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Publication Date
Fri Jun 27 2025
Journal Name
Mechanics Of Time-dependent Materials
Characterization and mechanical performance of stone mastic asphalt mixtures modified with SBS and PE polymers
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This study investigates the characterization and mechanical performance of Stone Mastic Asphalt (SMA) mixtures modified with two types of polymers: styrene–butadiene–styrene (SBS) and high-molecular-weight polyethylene (PE). Neat asphalt cement PG 64-16 was modified using a higher content of SBS and PE at concentrations of 6%, 7%, and 8% by weight of asphalt through the dry blending method to produce Highly Modified Asphalts (HiMA). The physical and rheological properties of the modified binders were evaluated using penetration, softening point, rotational viscosity, and dynamic shear rheometer (DSR) tests. Also, their phase compatibility and morphological changes were evaluated using the storage stability testing and scanning electron

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Publication Date
Wed Apr 30 2025
Journal Name
International Journal Of Kinesiology And Sports Science
Pilot Study: Impact of Plyometric Training on Goalkeepers’ Ball-Blocking Performance in Football Penalty Situations
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Background: Developing Goalkeeper’s performance is imperative to defence the goal. As the Football match’s nature needs implementning the skill with strength, and speed. so, the Goalkeeper demands special physical abilities that enabling him the ball blocking skill masterly. Objetive: The study aimed to identify the effect of developing some special physical abilities on the goalkeeper’s performance level while blocking executed balls from the penalty mark in football using plyometric training. Methodology: The experimental approach (continuous training that divided into two phases: General preparation, and Special preparation stage) was adopted for one experimental group by pre/post-measurements. The research sample was delib

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Publication Date
Wed Mar 01 2017
Journal Name
Superlattices And Microstructures
Enhanced photoelectrochemical performance of ZnO nanorod arrays decorated with CdS shell and Ag2S quantum dots
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Publication Date
Wed Jan 01 2025
Journal Name
Progress In Electromagnetics Research Letters
Optimize the Performance of Reconfigurable Antenna Based on Laser Treatment for Sub-6 GHz Applications
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Publication Date
Sat Jan 01 2022
Journal Name
International Journal Of Low-carbon Technologies
Performance evaluation of the photovoltaic thermal system with a fin array and surface zigzag layout
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Abstract<p>Solar photovoltaic (PV) has many environmental benefits and it is considered to be a practical alternative to traditional energy generation. The electrical conversion efficiency of such systems is inherently limited due to the relatively high thermal resistance of the PV components. An approach for intensifying electrical and thermal production of air-type photovoltaic thermal (PVT) systems via applying a combination of fins and surface zigzags was proposed in this paper. This research study aims to apply three performance enhancers: case B, including internal fins; case C, back surface zigzags; and case D, combinations of fins and surface zigzags; whereas the baseline smooth duct rep</p> ... Show More
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Publication Date
Tue Jun 23 2026
Journal Name
Journal Of Umm Al-qura University For Medical Science
Performance variation and implementation barriers of large language models in clinical healthcare: a systematic review
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Large language models (LLMs) are a rapidly evolving class of artificial intelligence with significant potential in clinical healthcare. Despite accelerating adoption, rigorous systematic evidence on clinical utility, patient safety, and implementation feasibility remains fragmented. To systematically review LLM applications across clinical domains, evaluate performance with appropriate contextual caveats, characterize implementation barriers, and identify ethical and regulatory considerations. Scientific databases were searched from January 2020 to January 2025. Studies evaluating transformer-based LLMs (≥10M parameters) in clinical settings were eligible. Data were independently double-extracted; quality was assessed using QUADAS-2, RE-A

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Publication Date
Tue Apr 08 2025
Journal Name
Heat Transfer
Experimental Study on the Performance of Gradient Pores Density Metal Foam in a Rectangular Channel
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ABSTRACT<p>Various approaches are employed to enhance the heat transfer coefficient and Nusselt number inside the channels. One of the techniques employed for these enhancements is the utilization of porous media. In the current article, a practical investigation of forced convection heat transfer in a rectangular cross‐section channel (0.05 × 0.1 m<sup>2</sup>) with 0.25 m length is conducted. A heater with a heat flux range (450–6000 W/m<sup>2</sup>) is imposed under a copper plate, and the other sides are covered by insulation layers. The air is considered as a working fluid with <italic>Re</italic> (600–2100). The test section is fully filled with gradient pore</p> ... Show More
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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Designing activity based costing systems ABC for transport services and its role in improving the efficiency of pricing decisions: بحث تطبيقي في الشركة العامة لادارة النقل الخاص
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  The research dealt with the design of the cost accounting system for the transport service and its Role in improving the efficiency of pricing decisions through the application of the cost system based on ABC activities. The main activities were defined and cost guides were to measure the cost of each service and to determine the cost of each service for the purpose of providing management with appropriate information and pricing decisions The problem of research in the lack of adoption by some public companies in the service sector on the cost accounting system to calculate the cost of service as well as the lack of identification of productive activities and service activities and therefore cannot make the appropriate decision t

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Publication Date
Wed Mar 29 2023
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Electrosorption of Hexavalent Chromium Ions by MnO2/Carbon Fiber Composite Electrode: Analysis and Optimization of the Process by Box-Behnken Design
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A nano manganese dioxide (MnO2) was electrodeposited galvanostatically onto a carbon fiber (CF) surface using the simple method of anodic electrodeposition. The composite electrode was characterized by field emission scanning electron microscopy (FESEM), and X-ray diffraction (XRD). Very few studies investigated the efficiency of this electrode for heavy metals removal, especially chromium. The electrosorption properties of the nano MnO2/CF electrode were examined by removing Cr(VI) ions from aqueous solutions. NaCl concentration, pH, and cell voltage were studied and optimized using the Box-Behnken design (BDD) to investigate their effects and interactions on the electrosorption process. The results showed that the

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Publication Date
Tue Jun 11 2019
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Investigation of cytotoxic activity and dissolution improvement of Teniposide by incorporation into acid treated carbon nanotube and dispersed by hydrophilic polymer
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Single Walled Carbon nanotubes (SWCNTs), as nano-needle structures, are good candidates as nanocarrier delivery systems that carry drug to the site of action. They are good due to their unique pharmaceutical properties. Teniposide is an anticancer drug, which is widely used, but it has a problem of low solubility. In this study, to improve the properties of carbon nanotubes, pre-functionalization of carbon nanotubes via carboxylation with strong acids has been performed and then functionalized through attaching them to the polymer and copolymer. Concurrently, a proper polymer-copolymer combination has been selected by the UV-Visible spectrometer at 880nm. It is selected based on the qualitative dispersibility analysis, the visual observa

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