Preferred Language
Articles
/
alkej-232
Influences of the Twisted Strips Insertion on the Performance of Flat Plate Water Solar Collector
...Show More Authors

Abstract

    In order to enhance the efficiency of flat plate solar water collectors without changing in its original shape and with low additional cost, twisted strips are inserted inside its riser pipes. Three flat plate collectors are used for test. Family of twisted strips are inserted inside each collector risers with different twisted ratios (TR=3,4,5). The collectors are connected in parallel mode (Z-Configuration) and are exposed to the same conditions (solar radiation and ambient temperature) .The experimental results show that, the highest heat transfer rate occurs at twisted ratio (3) .Consequently, for the same twisted ratio the daily efficiencies for the solar collector at different flow rate used (60,100 and 150) ℓ /hr. were 49 %, 57% and 63% respectively.

 Keywords: Twisted strip, solar collectors.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Mar 06 2016
Journal Name
Baghdad Science Journal
A Note on the Perturbation of arithmetic expressions
...Show More Authors

In this paper we present the theoretical foundation of forward error analysis of numerical algorithms under;• Approximations in "built-in" functions.• Rounding errors in arithmetic floating-point operations.• Perturbations of data.The error analysis is based on linearization method. The fundamental tools of the forward error analysis are system of linear absolute and relative a prior and a posteriori error equations and associated condition numbers constituting optimal of possible cumulative round – off errors. The condition numbers enable simple general, quantitative bounds definitions of numerical stability. The theoretical results have been applied a Gaussian elimination, and have proved to be very effective means of both a prior

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jan 30 2019
Journal Name
Journal Of The College Of Education For Women
Civil Administration on the Suburbs of Al–Kufa
...Show More Authors

We have found through research , that administrative institutions on the outskirts of Kufa and their management is not as important as administrative institution in place that were associated with it and subject to its control ,as it often was express power , or poor ( if true ) expression , directors of the center for the suburbs , as it became clear to our diversity of those administrative institutions and prominent role in the interest of the affairs of the people and society in all aspects of life , and are the functions and different staff from the highest authority the suburbs represented by house of representatives ( the workers ) ,then workers abscess and Al-dhaqan and not to mention for other jobs came the actions of Bhaltsier a

... Show More
View Publication Preview PDF
Publication Date
Sat Dec 28 2019
Journal Name
International Journal Of Simulation: Systems, Science & Technology
On the Estimation of Nonparametric Copula Density Functions
...Show More Authors

In this research, we present a nonparametric approach for the estimation of a copula density using different kernel density methods. Different functions were used: Gaussian, Gumbel, Clayton, and Frank copula, and through various simulation experiments we generated the standard bivariate normal distribution at samples sizes (50, 100, 250 and 500), in both high and low dependency. Different kernel methods were used to estimate the probability density function of the copula with marginal of this bivariate distribution: Mirror – Reflection (MR), Beta Kernel (BK) and transformation kernel (KD) method, then a comparison was carried out between the three methods with all the experiments using the integrated mean squared error. Furthermore, some

... Show More
View Publication
Publication Date
Wed Jun 14 2023
Journal Name
Al-academy
Visual looting on the covers of international magazines
...Show More Authors

The strategy of designing the covers of international magazines emerges as one of the expressive means that reflect the emotional and expressive aspects and employ them according to the spatial transformations and the struggles of globalization to usurp the intellectual, cultural, value and civilizational essence of man, which makes him vulnerable to psychological and spiritual alienation and becomes the abstract meaning of identity and culture, and the empowerment of cultural invasion and the control of consumer thought The contemporary globalist on the largest area and the globalization of the peoples of the world, and the study came in the first chapter: the general framework that includes the problem of the research to raise in our m

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Mar 03 2026
Journal Name
Al–bahith Al–a'alami
THE EFFECT OF FASHIONISTA ON FEMALE BODY IMAGE
...Show More Authors

The research aims to reveal the relationship between the use of social networking sites and the image that females make about their physical formation, the nature of the effects, their value judgments about the image of their bodies, their attitudes toward plastic surgery, the most important types of these processes for them, their motivations to conduct them, and the cultural pressures they are exposed to. The study, moreover, investigates in the effects of those plastic surgery on their behavior as active and interacting users with what is published on social media, according to the theory of social comparison. This paper is an attempt to understand the pattern of social networking

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jun 30 2001
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Effect of Mud Compositions on the Rheological Behavior
...Show More Authors

The aim of this work is to study the effect of mud compositions on it’s rheological behavior under high temperature conditions. Seventeen samples of five types of water base mud in which (fresh water bentonite mud. Lignosulphonate mud, gypsum mud, polymer mud, and salt saturated mud) were tested with different temperatures using the fann viscometer model 50-c. All the tested samples, except the fresh water bentonite mud, have the same trend reduction in both plastic viscosity and yield point with increasing temperature. Six rheological models has been adapted: Bingham plastic, power law, Casson model represent the laboratory data accurately  

View Publication Preview PDF
Publication Date
Thu Dec 06 2018
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Studying the Effect of Variables on Acyclovir Microsponge
...Show More Authors
The aim of the present investigation was to develop a microsponge delivery system of acyclovir to control its release when applied topically thereby reducing dosing frequency and enhancement patient compliance. The microsponges were produced by the oil in oil emulsion solvent diffusion method. The effect of different formulation and process variables such as internal phase volume, polymer type, drug-polymer ratio, stirring speed and stirring duration on microsponge production yield, loading efficiency, particle size and in-vitro drug release was evaluated. The result showed that the microsponge F2 prepared from Eudrajet RS polymer had optimum physical properties regarding the loading efficiency of 99.71_+ 0.7% and product
... Show More
View Publication Preview PDF
Scopus (5)
Scopus Crossref
Publication Date
Sun Dec 03 2017
Journal Name
Al-khwarizmi Engineering Journal
Performance of Turbo-Codes with Some Proposed Interleaver Schemes
...Show More Authors

This paper describes a number of new interleaving strategies based on the golden section. The new interleavers are called golden relative prime interleavers, golden interleavers, and dithered golden interleavers. The latter two approaches involve sorting a real-valued vector derived from the golden section. Random and so-called “spread” interleavers are also considered. Turbo-code performance results are presented and compared for the various interleaving strategies. Of the interleavers considered, the dithered golden interleaver typically provides the best performance, especially for low code rates and large block sizes. The golden relative prime interleaver is shown to work surprisingly well for high puncture rates. These interleav

... Show More
View Publication Preview PDF
Publication Date
Sat Oct 01 2022
Journal Name
Baghdad Science Journal
Modeling Jar Test Results Using Gene Expression to Determine the Optimal Alum Dose in Drinking Water Treatment Plants
...Show More Authors

Coagulation is the most important process in drinking water treatment. Alum coagulant increases the aluminum residuals, which have been linked in many studies to Alzheimer's disease. Therefore, it is very important to use it with the very optimal dose. In this paper, four sets of experiments were done to determine the relationship between raw water characteristics: turbidity, pH, alkalinity, temperature, and optimum doses of alum [   .14 O] to form a mathematical equation that could replace the need for jar test experiments. The experiments were performed under different conditions and under different seasonal circumstances. The optimal dose in every set was determined, and used to build a gene expression model (GEP). The models were co

... Show More
View Publication Preview PDF
Scopus (12)
Crossref (6)
Scopus Clarivate Crossref
Publication Date
Tue May 01 2012
Journal Name
Iraqi Journal Of Physics
Using remote sensing techniques to monitoring and evaluate the water cover in AL_Razzaza lake: Iraq at deferent periods
...Show More Authors

Multi-spectral satellite images of the Landsat satellite by the tow sensitive Thematic Mapper (TM) and Thematic Mapper Enhancement (ETM+), which covered the study area located south east of Iraq. In this research; used the sixth thermal spectral band (Thermal Band) for study the water cover in the Al-Razzaza Lake located within the province of Karbala. We intended to study the cover a case of the study area, used satellite images showing the status of region during the period from 1990 to 2001 and 2007. From this study we conclude that cover the water of the study area change in sequence case to decrease during these years.

View Publication Preview PDF