Preferred Language
Articles
/
joe-935
Experimental Investigation of Thermal Performance of a Solar Chimney Provided with a Porous Absorber Plate
...Show More Authors

 

Experimental investigation of the influence of inserting the metal foam to the solar chimney to induce natural ventilation are described and analyzed in this work. To carry out the experimental test, two identical solar chimneys (without insertion of metal foam and with insertion of metal foam) are designed and placed facing south with dimensions of length× width× air gap (2 m× 1 m× 0.2 m). Four incline angles are tested (20o,30o,45o,60o) for each chimney in Baghdad climate condition (33.3o latitude, 44.4o longitude) on October, November, December 2018. The solar chimney performance is investigated by experimentally recording absorber plate and air temperatures and velocity of air. Results indicated that the using metal foam absorber plate lead to reducing the mean temperature of absorber plate by 6.7 °C as a result, the values of chimney outlet air temperature increased. The daily solar chimney efficiency enhanced by 58.7% and the useful energy received also increased. The existence of metal foam caused higher air velocity at the exit and increasing in the ventilation rate that the maximum ventilate rate obtained from the solar chimney is 5.96 1/hr for 27 m3 volume of room at solar irradiance of 730 W/m2   for chimney incline angle of 60o. The results of the experimental work show that the addition of metal foam to the solar chimney as an absorber plate is an efficient method to enhance the characteristics of heat transfer and the thermal performance of the solar chimney in the weather condition of Iraq.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Engineering
A Computational Fluid Dynamics Investigation of using Large-Scale Geometric Roughness Elements in Open Channels
...Show More Authors

The hydraulic behavior of the flow can be changed by using large-scale geometric roughness elements in open channels. This change can help in controlling erosions and sedimentations along the mainstream of the channel. Roughness elements can be large stone or concrete blocks placed at the channel's bed to impose more resistance in the bed. The geometry of the roughness elements, numbers used, and configuration are parameters that can affect the flow's hydraulic characteristics. In this paper, velocity distribution along the flume was theoretically investigated using a series of tests of T-shape roughness elements, fixed height, arranged in three different configurations, differ in the number of lines of roughness element

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Ndt & E International
Porosity evaluation of in-service thermal barrier coated turbine blades using a microwave nondestructive technique
...Show More Authors

View Publication
Scopus (20)
Crossref (21)
Scopus Clarivate Crossref
Publication Date
Sat Jan 01 2011
Journal Name
Al-mustansiriyah Journal Of Science
TMA and DSC study of molded and annealed polyester: a thermal expansion and crystallization evaluation
...Show More Authors

Thermomechanical analysis (TMA) and differential scanning calorimetry (DSC) are used to investigate the effect of molding and annealing of polyester on the behavior of thermal expansion and crystallization since these factors play role in the reprocessing or recycling of the polymer. The dynamic mode of the TMA provides enhanced characterization information about the polyester since it separates the transitions into reversible and irreversible signals, and also reveals the progress of the amorphous regions as the polyester loses strength with the increasing temperature approaching melting. Slow cooling after annealing brings crystallization that may be attributed to molecular chain straightening due to orientation.

View Publication Preview PDF
Publication Date
Thu Jul 01 2021
Journal Name
Solar Energy
A new approach for employing multiple PCMs in the passive thermal management of photovoltaic modules
...Show More Authors

View Publication
Scopus (118)
Crossref (113)
Scopus Clarivate Crossref
Publication Date
Wed Jan 01 2020
Journal Name
Energy Conversion And Management
Improved PCM melting in a thermal energy storage system of double-pipe helical-coil tube
...Show More Authors

View Publication
Scopus (153)
Crossref (148)
Scopus Clarivate Crossref
Publication Date
Sun Sep 22 2019
Journal Name
Baghdad Science Journal
Thermal Conductivity Performance of Silica Aerogel after Exposition on Different Heating under Ambient Pressure
...Show More Authors

         The varied thermal conductivity (insulation) of silica aerogel with heating for different pH has been investigated, it has been depended on ambient pressure drying method in the preparing silica aerogel samples, also six different pH of samples (1, 2, 3, 7, 8 and 9) were treated under five degree of heating with (50,100,150,200 and 250) ᴼC. This technique is important to test the carry-outs hydrophobic silica to temperature without high-quality material changes in the basic characteristics. The hot-wire technique is used in this work to examine the thermal conductivity, Fourier Transform Infrared Spectroscopy (FTIR) depended to characterize the bonds and their artificial by heating. Resu

... Show More
View Publication Preview PDF
Scopus (15)
Crossref (9)
Scopus Clarivate Crossref
Publication Date
Sun Apr 30 2023
Journal Name
Al-kindy College Medical Journal
The Ameliorating Effect of Ashwagandha (Withania Somnifera) Extract on Hippocampus and Growth Plate Changes Associated With Propylthiouracil Induced Hypothyroidism in Juvenile Rats : Ashwagandha on Hippocampus and Growth Plate Changes Associated With hypothyroid rats
...Show More Authors

Background: Hypothyroidism is a decrease in the production of the thyroid hormones and leads to gland dysfunction. Ashwagandha extract was used as an ayurvedic treatment and supposed to be as antihypothyroidism agent.

Objectives: to investigate the impact of ashwagandha (Ash) extract on propylthiouracil (PTU)-induced hypothyroidism in rats.

Subjects and Methods: The rats were divided into three groups, control group, PTU (hypothyroid) group (6mg/kg/day by oral route), PTU (6mg/kg/day by oral route) +Ash (50mg/kg/day by oral route) treated group. All treatment continued for

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (2)
Scopus Crossref
Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Experimental Investigations Performance for (VCC) Using 2-Way (PFCV) Type (2FRE)
...Show More Authors

In modern hydraulic control systems, the trend in hydraulic power applications is to improve efficiency and performance. “Proportional valve” is generally applied to pressure, flow and directional-control valves which continuously convert a variable input signal into a smooth and proportional hydraulic output signal. It creates a variable resistance (orifice) upstream and downstream of a hydraulic actuator, and is meter in/meter out circuit and hence pressure drop, and power losses are inevitable. If velocity (position) feedback is used, flow pattern control is possible. Without aforementioned flow pattern, control is very “loose” and relies on “visual” feed back by the operator. At this point, we should examine how this valv

... Show More
View Publication Preview PDF
Publication Date
Wed Mar 29 2023
Journal Name
Journal Of The College Of Education For Women
A Cognitive Linguistic Study of the Present Simple: An Experimental Study in the University of Baghdad
...Show More Authors

Some research reports that cognitive grammar (CG) theory has good contributions to teaching English as a foreign language. In this research, the researchers seek to apply this theory and its principles when teaching the simple present tense to Iraqi students who face difficulties in differentiating between the multiple usages of this tense. To achieve this objective, the researchers have conducted an experimental study on a group of 60 Iraqi students in the University of Baghdad, College of Education for Women. Langacker’s (2003) theory has been adopted in the analysis of the cognitive relations to understand the common and different connections of these usages of the simple present. The study has concluded that the cognitive grammar t

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Mar 15 2019
Journal Name
Al-khwarizmi Engineering Journal
Experimental and Theoretical Study of the Energy Flow of a Two Stages Four Generators Adsorption Chiller
...Show More Authors

This work is concerned with a two stages four beds adsorption chiller utilizing activated carbon-methanol adsorption pair that operates on six separated processes. The four beds that act as thermal compressors are powered by a low grade thermal energy in the form of hot water at a temperature range of 65 to 83 °C.  As well as, the water pumps and control cycle consume insignificant electrical power. This adsorption chiller consists of three water cycles. The first water cycle is the driven hot water cycle. The second cycle is the cold water cycle to cool the carbon, which adsorbs the methanol. Finally, the chilled water cycle that is used to overcome the building load. The theoretical results showed that average cycle cooling power

... Show More
View Publication Preview PDF
Crossref (1)
Crossref