Preferred Language
Articles
/
LoYp1YYBIXToZYALd7UO
Investigation of Heat Transfer Enhancement in a Triple Tube Latent Heat Storage System Using Circular Fins with Inline and Staggered Arrangements
...Show More Authors

Inherent fluctuations in the availability of energy from renewables, particularly solar, remain a substantial impediment to their widespread deployment worldwide. Employing phase-change materials (PCMs) as media, saving energy for later consumption, offers a promising solution for overcoming the problem. However, the heat conductivities of most PCMs are limited, which severely limits the energy storage potential of these materials. This study suggests employing circular fins with staggered distribution to achieve improved thermal response rates of PCM in a vertical triple-tube heat exchanger involving two opposite flow streams of the heat-transfer fluid (HTF). Since heat diffusion is not the same at various portions of the PCM unit, different fin configurations, fin dimensions and HTF flow boundary conditions were explored using computational studies of melting in the PCM triple-tube system. Staggered configuration of fin distribution resulted in significant increases in the rates of PCM melting. The results indicate that the melting rate and heat charging rate could be increased by 37.2 and 59.1%, respectively, in the case of staggered distribution. Furthermore, the use of lengthy fins with smaller thickness in the vertical direction of the storage unit resulted in a better positive role of natural convection; thus, faster melting rates were achieved. With fin dimensions of 0.666 mm × 15 mm, the melting rate was found to be increased by 23.6%, when compared to the base case of 2 mm × 5 mm. Finally, it was confirmed that the values of the Reynolds number and inlet temperatures of the HTF had a significant impact on melting time savings when circular fins of staggered distribution were included.

Scopus Clarivate Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Mar 20 2020
Journal Name
Journal Of Xi'an University Of Architecture & Technology
Academic Laboratory Skills For Chemistry Students at the College of Education For Pure Sciences -Ibn Al Haitham
...Show More Authors

The current research aims to find out the extent to which students of the Faculty of Education for Pure Sciences\/Ibn al-Haitham have owned laboratory academic skills, the researcher adopted a descriptive research approach to conform to the goal of the research, the research sample the consisted of 140 students from the Department of Chemistry Phase II, The research tool, which consisted of a measure of laboratory academic skills, which consisted of seven skills and consisted of 28 paragraphs (four paragraphs per field), was prepared and the pent-up scale was chosen because the selected sample were university students, and the results showed the ownership of students' skills of laboratory academic skills other than skill The use of the libr

... Show More
Preview PDF
Publication Date
Wed Jun 30 2004
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Studying Effect of Elongational Viscosity on the Velocity Distribution for Dry/Wet-Spun Nascent Hollow Fiber Membrane
...Show More Authors

View Publication Preview PDF
Publication Date
Wed May 01 2019
Journal Name
Journal Of Engineering
Optimization of Friction Stir Welding Process Parameters to joint 7075-T6 Aluminium Alloy by Utilizing Taguchi Technique
...Show More Authors

In this study, a 3 mm thickness 7075-T6 aluminium alloy sheet was used in the friction stir welding process. Using the design of experiment to reduce the number of experiments and to obtain the optimum friction stir welding parameters by utilizing Taguchi technique based on the ultimate tensile test results. Orthogonal array of L9 (33) was used based on three numbers of the parameters and three levels for each parameter, where shoulder-workpiece interference depth (0.20, 0.25, and 0.3) mm, pin geometry (cylindrical thread flat end, cylindrical thread with 3 flat round end, cylindrical thread round end), and thread pitch (0.8, 1, and 1.2) mm) this technique executed by Minitab 17 software. The results showed th

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Mon Apr 03 2023
Journal Name
Journal Of Educational And Psychological Researches
Fitting Scoring Rubrics for Electronic Portfolio to Partial Credit Model According to the Number of Assumed Dimensions
...Show More Authors

Abstract

 

The current research aims to reveal the extent to which all scoring rubrics data for the electronic work file conform to the partial estimation model according to the number of assumed dimensions. The study sample consisted of (356) female students. The study concluded that the list with the one-dimensional assumption is more appropriate than the multi-dimensional assumption, The current research recommends preparing unified correction rules for the different methods of performance evaluation in the basic courses. It also suggests the importance of conducting studies aimed at examining the appropriateness of different evaluation methods for models of response theory to the

... Show More
View Publication Preview PDF
Publication Date
Tue Dec 31 2013
Journal Name
Al-khwarizmi Engineering Journal
Design of an Adaptive PID Neural Controller for Continuous Stirred Tank Reactor based on Particle Swarm Optimization
...Show More Authors

 A particle swarm optimization algorithm and neural network like self-tuning PID controller for CSTR system is presented. The scheme of the discrete-time PID control structure is based on neural network and tuned the parameters of the PID controller by using a particle swarm optimization PSO technique as a simple and fast training algorithm. The proposed method has advantage that it is not necessary to use a combined structure of identification and decision because it used PSO. Simulation results show the effectiveness of the proposed adaptive PID neural control algorithm in terms of minimum tracking error and smoothness control signal obtained for non-linear dynamical CSTR system.

View Publication Preview PDF
Publication Date
Tue Sep 11 2018
Journal Name
Iraqi Journal Of Physics
An experimental cross-section measurement of 10B(n,α)7Li reaction on counting alpha particles track density
...Show More Authors

The present work determines the particle size based only on the number of tracks detected in a cluster created by a hot particle on the CR-39 solid state nuclear track detector and depending on the exposure time. The mathematical model of the cross section developed here gives the relationship between alpha particle emitting from the (n, α) reaction and the number of tracks created and distribution of tracks created on the surface of the track detector. In an experiment performed during this work, disc of boron compound (boric acid or sodium tetraborate) of different weights were prepared and exposed to thermal neutron from the source. Chemical etching is processes of path formation in the detector, during which a suitable etching solut

... Show More
View Publication
Crossref
Publication Date
Wed Oct 17 2018
Journal Name
Iraqi Journal Of Laser
Thermal Effects of 940 nm Diode Laser on Dental Socket Blood after Teeth Extraction for Diabetic Patients
...Show More Authors

Abstract: Background: High percentage of diabetes patients complain from post extraction hemorrhage. Many types of hemostatic materials are used to stop bleeding after teeth extraction: diode lasers are good hemostatic agents owing to their highly absorption by hemoglobin therefore they are used in soft tissue procedures with relatively no effects on dental hard tissues due to their poorly absorption by water and hydroxyapatite. Objectives: The aim of this study is to evaluate the efficiency of diode laser to assist the clot formation after tooth extraction for type II diabetes patients with minimum temperature elevation to prevent periodontal destruction. Materials and methods: From 12 type II diabetes patients (7 males and 5 females wi

... Show More
View Publication Preview PDF
Publication Date
Mon Jun 20 2022
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
CONCHOLOGICAL VARIABILITY OF TERRESTRIAL MOLLUSK CHONDRULOPSINA FEDTSCHENKOI (ANCEY, 1886) (GASTROPODA, PULMONATA, ENIDAE) FROM THE ZARAFSHAN RANGE, UZBEKISTAN
...Show More Authors

The article presents the results of studying the conchological variability of the terrestrial mollusk Chondrulopsina fedtschenkoi (Ancey, 1886), known to occur in three regions of the Zaravshan Range (Central Asia): the Urgutsay Gorge, the vicinity of the Gissarak Reservoir and the Ingichka-Irmak Gorge. Conchological variability was determined based on statistical analysis. The climate of the three regions is different, and environmental factors have led to changes in the mollusk shell. The shells have changed in response to environmental factors, these are their adaptive traits for survival; the variability of conchological features is also reflected in the color of the shell, and the intensive development of the color of the shell in m

... Show More
View Publication Preview PDF
Scopus (7)
Crossref (1)
Scopus Crossref
Publication Date
Thu Feb 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
The technique of converting multi-choice mathematical programming into linear mathematical programming to find the optimal solution
...Show More Authors

The study deals with the issue of multi-choice linear mathematical programming. The right side of the constraints will be multi-choice. However, the issue of multi-purpose mathematical programming can not be solved directly through linear or nonlinear techniques. The idea is to transform this matter into a normal linear problem and solve it In this research, a simple technique is introduced that enables us to deal with this issue as regular linear programming. The idea is to introduce a number of binary variables And its use to create a linear combination gives one parameter was used multiple. As well as the options of linear programming model to maximize profits to the General Company for Plastic Industries product irrigation sy

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 17 2019
Journal Name
Baghdad Science Journal
Toxic Effects of Purified Microcystins from Soil Blue-Green Alga Oscillatoria pseudogeminata on Tomato Plant Lycopersicon esculentum
...Show More Authors

The current study included the isolation, purification and cultivation of blue-green alga Oscillatoria pseudogeminata G.Schmidle from soil using the BG-11liquid culture medium for 60 days of cultivation. The growth constant (k) and generation time (G) were measured which (K=0.144) and (G=2.09 days).

Microcystins were purified and determined qualitatively and quantitatively from this alga by using the technique of enzyme linked immunosorbent assay (Elisa Kits). The alga showed the ability to produce microcystins in concentration reached 1.47 µg/L for each 50 mg DW. Tomato plants (Lycopersicon esculentum) aged two months were irrigated with three concentrations of purified microcystins 0.5 , 3.0 and 6.0

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Clarivate Crossref