Preferred Language
Articles
/
alkej-313
Experimental and Theoretical Study for Performance Enhancement of Air Solar Collectors by Using Different Absorbers
...Show More Authors

An experimental and theoretical study has been done to investigate the thermal performance of different types of air solar collectors, In this work air solar collector with a dimensions of (120 cm x90 cm x12 cm) , was tested under climate condition of  Baghdad city with a (43° tilt angel)  by using  the absorber plate (1.45 mm thickness, 115 cm height x 84 cm width), which was manufactured from iron painted with a black matt.

The experimental test deals with five types of absorber:-

 Conventional smooth flat plate absorber , Finned absorber , Corrugated absorber plate, Iron wire mesh on absorber And matrix of porous media  on absorber .

The hourly and average efficiency of the collectors were investigated for three values of mass flow rates (0.016 kg/s to 0.027 kg/s) for each type of collector and then the porosity for the last collector type was tested by changing the porosity of porous media.

A typical air solar collector has been studied Theoretically to build a standard software for testing any type of air solar collectors with local weather data .

From the experimental study  it can be seen  by using some obstacle material to the air flow (fins, corrugated absorber plate, iron wire mesh porous media on the absorber) could be enhanced the efficiencies not less than 4 %  for  finned type and 8 % for corrugated and 25 % for mesh and 30  %  for porous media comparing with flat plate (smooth) collector .

Theoretically, the results showed that the collector with high convention heat transfer coefficient porous media has high  hourly efficiency about (η = 56 %) and iron wire mesh on absorber ( η = 52 % ), on the other  side the minimum  performance occurred in the  flat plate absorber  (η = 28  %).

Comparison of results reveals that the theoretical predictions agree reasonably well with experimental results. And the difference between the theoretical   and experimental efficiency in general was between (1─ 15 %).

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Mar 01 2020
Journal Name
Baghdad Science Journal
A Comparative Study on the Double Prior for Reliability Kumaraswamy Distribution with Numerical Solution
...Show More Authors

This work, deals with Kumaraswamy distribution. Kumaraswamy (1976, 1978) showed well known probability distribution functions such as the normal, beta and log-normal but in (1980) Kumaraswamy developed a more general probability density function for double bounded random processes, which is known as Kumaraswamy’s distribution. Classical maximum likelihood and Bayes methods estimator are used to estimate the unknown shape parameter (b). Reliability function are obtained using symmetric loss functions by using three types of informative priors two single priors and one double prior. In addition, a comparison is made for the performance of these estimators with respect to the numerical solution which are found using expansion method. The

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Thu Dec 28 2017
Journal Name
Al-khwarizmi Engineering Journal
An Autocorrelative Approach for EMG Time-Frequency Analysis
...Show More Authors

As they are the smallest functional parts of the muscle, motor units (MUs) are considered as the basic building blocks of the neuromuscular system. Monitoring MU recruitment, de-recruitment, and firing rate (by either invasive or surface techniques) leads to the understanding of motor control strategies and of their pathological alterations. EMG signal decomposition is the process of identification and classification of individual motor unit action potentials (MUAPs) in the interference pattern detected with either intramuscular or surface electrodes. Signal processing techniques were used in EMG signal decomposition to understand fundamental and physiological issues. Many techniques have been developed to decompose intramuscularly detec

... Show More
View Publication Preview PDF
Publication Date
Sat Dec 15 2018
Journal Name
Journal Of The College Of Education For Women
Social responsibility of kindergarten teachers Eligibility and Government (Comparative Study)
...Show More Authors

      The present research aims to identify the social responsibility of the kindergarten teachers of the civil and governmental schools (comparative study)? For the purpose of achieving the objectives of the research, the following formulas were formulated:

- Are there statistically significant differences at the level of (0.05) among the kindergarten teachers in the social responsibility scale?

 The current research was limited to kindergarten teachers (governmental and non-governmental) in the Directorate General of Education Baghdad Rusafa / Second.

The main research sample consisted of (100) teachers, (50) teachers from government kindergartens and (50) female kindergarten teache

... Show More
View Publication Preview PDF
Publication Date
Tue Jan 12 2021
Journal Name
Pollution Research
DETERMINATION OF ANILINE IN WASTEWATER BY CLOUDPOINT EXTRACTION FOLLOWED BY HPLC USING 8-HYDROXYQUINOLINE AS A DERIVATIZATION AGENT
...Show More Authors

A procedure, depending on the derivatization and determination of aniline was depicted andvalidated in this study. 8-hydroxyquinoline (8-HQ) was used as the derivatizing agent for thedetermination of aniline. An optimization study was performed for the derivatization reaction, i.e.,the diazonium coupling reaction, the optimum parameters were as follows: 22 mM of hydrochloricacid, 54mM of sodium hydroxide, and 1.8mM of sodium nitrate. The optimization study of themethod of cloud point extraction (CPE) revealed that the extraction solvent was 0.5 ml of Triton X-100, the optimum temperature was 90 °C, and the incubation time was 25 min. The linearity,correlation coefficients, molar absorptivities, and limits of detection were improved using t

... Show More
Publication Date
Thu Jun 30 2016
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
CFD Simulation of Air Flow Patterns in a Spray Dryer Fitted With a Rotary Disk
...Show More Authors

The air flow pattern in a co-current pilot plant spray dryer fitted with a rotary disk atomizer was determined experimentally and modelled numerically using Computational Fluid Dynamics (CFD) (ANSYS Fluent ) software. The CFD simulation used a three dimensions system, Reynolds-Average Navier-Stokes equations (RANS), closed via the RNG k −ε turbulence model. Measurements were carried out at a rotation of the atomizer (3000 rpm) and when there is no rotation using a drying air at 25 oC and  air velocity at the inlet of  5 m/s without swirl. The air flow pattern was predicted experimentally using cotton tufts and digital anemometer. The CFD simulation predicted a downward central flowing air core surrounded by a slow

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 01 2022
Journal Name
Baghdad Science Journal
Assessment of Air Pollution around Durra Refinery (Baghdad) from Emission NO2 Gas at April Month
...Show More Authors

Nitrogen dioxide NO2 is one of the most dangerous contaminant in the air, its toxic gas that cause disturbing respiratory effects, most of it emitted from industrial sources especially from the stack of power plants and oil refineries. In this study Gaussian equations modelled by Matlab program to state the effect of pollutant NO2 gas on area around Durra refinery, this program also evaluate some elements such as wind and stability and its effect on stacks height. Data used in this study is the amount of fuel oil and fuel gas burn inside refinery at a year 2017. Hourly April month data chosen as a case study because it’s unsteady month. After evaluate emission rate of the all fuel and calculate exit velocity from

... Show More
View Publication Preview PDF
Scopus (19)
Crossref (7)
Scopus Clarivate Crossref
Publication Date
Thu Sep 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Financial Depth Measurements / Analytical Study in Selected Countries for the Period 1980-2008
...Show More Authors

This research deals with the most important indicators used to measure the phenomenon of financial depth, beyond the traditional indicators, which are called quantitative indicators, which is shown to be inadequate to show the facts accurately, but it may come in the results of a counterfactual, although reliable in econometric studies done in this regard.

Therefore, this research has sought to put forward alternative indicators, is the structural indicators, and financial prices, and availability of financial instruments, and cost of transactions concluded, in order to measure the phenomenon of financial depth.

After using and analyzing data collected from countries the research

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Mon Feb 23 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Cephalometric analysis of craniofacial deformity of ?-thalassemic major by using computed tomography
...Show More Authors

Background: Thalassemia is a hereditary anemia resulting from defects in hemoglobin production. ?- thalassemia caused by decrease in the production of ?- globin chains affect multiple organs and is associated with cranio-oro-facial deformity which include prominent cheek bones and protrusive premaxilla with depression of the nasal bridge often referred to as “rodent or chip-munk face” with small mandible and Cl.II skeletal relationship. This study aimed to investigate cephalometric craniofacial parameters (skeletal) of ?- thalassemic major patients by using computed tomography and to compare findings with a group of healthy patients in the same age group. Subject, Materials and Method: The study included (40) patients with ?- thalassemi

... Show More
View Publication Preview PDF
Publication Date
Sat May 01 2021
Journal Name
Journal Of Physics: Conference Series
Theoretical Estimation of Electronic Flow Rate at Al-TiO<sub>2</sub> Interfaces System
...Show More Authors
Abstract<p>The mechanism of the electronic flow rate at Al-TiO<sub>2</sub> interfaces system has been studied using the postulate of electronic quantum theory. The different structural of two materials lead to suggestion the continuum energy level for Al metal and TiO<sub>2</sub> semiconductor. The electronic flow rate at the Al-TiO2 complex has affected by transition energy, coupling strength and contact at the interface of two materials. The flow charge rate at Al-TiO2 is increased by increasing coupling strength and decreasing transition energy.</p>
View Publication
Scopus (4)
Crossref (3)
Scopus Crossref
Publication Date
Tue Dec 05 2023
Journal Name
Engineering, Technology &amp; Applied Science Research
Theoretical Analysis of Composite RC Beams with Pultruded GFRP Beams subjected to Impact Loading
...Show More Authors

Glass Fiber Reinforced Polymer (GFRP) beams have gained attention due to their promising mechanical properties and potential for structural applications. Combining GFRP core and encasing materials creates a composite beam with superior mechanical properties. This paper describes the testing encased GFRP beams as composite Reinforced Concrete (RC) beams under low-velocity impact load. Theoretical analysis was used with practical results to simulate the tested beams' behavior and predict the generated energies during the impact loading. The impact response was investigated using repeated drops of 42.5 kg falling mass from various heights. An analysis was performed using accelerometer readings to calculate the generalized inertial load. The in

... Show More
View Publication