Preferred Language
Articles
/
3xdlUpEBVTCNdQwC8pS3
Optical CDMA Coded STBC Based on Chaotic Technique in FSO Communication Systems
...Show More Authors

Free-Space Optical (FSO) can provide high-speed communications when the effect of turbulence is not serious. However, Space-Time-Block-Code (STBC) is a good candidate to mitigate this seriousness. This paper proposes a hybrid of an Optical Code Division Multiple Access (OCDMA) and STBC in FSO communication for last mile solutions, where access to remote areas is complicated. The main weakness effecting a FSO link is the atmospheric turbulence. The feasibility of employing STBC in OCDMA is to mitigate these effects. The current work evaluates the Bit-Error-Rate (BER) performance of OCDMA operating under the scintillation effect, where this effect can be described by the gamma-gamma model. The most obvious finding to emerge from the analysis is that the BER can be enhanced by orders of magnitude for different numbers of users and different values of scintillation effects using a MIMO

Scopus Crossref
View Publication
Publication Date
Fri Dec 22 2023
Journal Name
Eastern-european Journal Of Enterprise Technologies
Evaluating the impact of structure parameters on the acoustic performance of an exhaust muffler with shells
...Show More Authors

Recently, environmental noise has arisen from various sources, such as those from exhaust mufflers of combustion engines found in cars, trucks, or power generators, which produce significant noise during their operation. Controlling the radiated noise from these mufflers is a major factor in improving acoustic comfort and minimizing the impact on the surrounding communities. Numerous research has been presented for this reason by modification of the internal structure of the exhaust muffler. The main objective of this work is to reduce the noise level emitted from exhaust mufflers. This can be achieved by adjusting structure parameters to attenuate the surrounding environment's radiated noise. Analysis of pressure-wave propagation h

... Show More
View Publication
Scopus (2)
Crossref (1)
Scopus Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Journal Of Animal Behaviour And Biometeorology
Comprehension of the zinc chloride's ameliorative apoptotic and genotoxic effects on mice with cadmium-induced hepatotoxicity
...Show More Authors

View Publication
Scopus (3)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Thu Dec 01 2011
Journal Name
Iraqi Journal Of Physics
Influence of water absorption on fatigue behavior for chopped and woven-glass-fibers-reinforced PMMA denture
...Show More Authors

The influence of fiber orientation and water absorption on fatigue crack growth resistance for cold cure acrylic (PMMA) reinforced by chopped and woven -glass-fibers were investigated. A weight of 2 g for chopped fibers and the same weight for woven -glass-fibers (one layer) were used to prepare samples. Some of these samples would storage in dry condition; the others were immersed in water for 15 days. Fatigue test was carried out. The results shows that, for PMMA, the initial bending stress for dry specimen was 3.392 N/cm2 and the number of cycles were 1364, the initial bending stress for wet samples was 4.20 N/cm2, and the number of cycles was 2411. The samples would cut in two pieces because of the cracks would propagated fast during

... Show More
View Publication Preview PDF
Publication Date
Mon Aug 01 2022
Journal Name
Hiv Nursing
The Influence of Some Vitamins and Biochemical Parameters on Iraqi Females’ Patients with Malignant Breast Cancer"
...Show More Authors

The Influence of Some Vitamins and Biochemical Parameters on Iraqi Females’ Patients with Malignant Breast Cancer"

Preview PDF
Publication Date
Thu Dec 01 2022
Journal Name
Journal Of Engineering
Multi-Criteria Optimization for Governmental Projects Priority Ranking Depending on Fuzzified Experts’ Opinion using Hygiene Approach
...Show More Authors

Each organization struggles to exploit each possible opportunity for gaining success and continuing with its work carrier. In this field, organization success can be concluded by fulfilling end user requirements combined with optimizing available resources usage within a specified time and acceptable quality level to gain maximum profit. The project ranking process is governed by the multi-criteria environment, which is more difficult for the governmental organization because other organizations' main target is maximizing profit constrained with available resources. The governmental organization should consider human, social, economic and many more factors. This paper focused on building a multi-criteria optimizing proje

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sat Aug 01 2020
Journal Name
Journal Of Engineering Science And Technology (jestec)
Influence of A River Water Quality on The Efficiency of Water Treatment Using Artificial Neural Network
...Show More Authors

Tigris River is the lifeline that supplies a great part of Iraq with water from north to south. Throughout its entire length, the river is battered by various types of pollutants such as wastewater effluents from municipal, industrial, agricultural activities, and others. Hence, the water quality assessment of the Tigris River is crucial in ensuring that appropriate and adequate measures are taken to save the river from as much pollution as possible. In this study, six water treatment plants (WTPs) situated on the two-banks of the Tigris within Baghdad City were Al Karkh; Sharq Dijla; Al Wathba; Al Karama; Al Doura, and Al Wahda from northern Baghdad to its south, that selected to determine the removal efficiency of turbidity and

... Show More
Publication Date
Tue Mar 01 2011
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The effect of differentiation strategy on achieve competitive advantage: survey comparison between the companies maintenance service
...Show More Authors

Is to obtain competitive advantage legitimate objective pursued by all organizations to achieve, because they live today in environments of rapid change and dynamic in order to meet the demands of the customer changing as well as intense competition between the organizations, which requires them to get the location of competitive markets in order to do this will remain to do the building and strengthening competitive advantage to be able to achieve, but that this feature is not easy and is not only through the identification and use of a successful strategy for a competitive standard and then manage it successfully. Hence the research problem of determining the sources of differentiation strategy and its impact on the dimensions of compe

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 17 2019
Journal Name
Baghdad Science Journal
On Generalized Continuous Fuzzy Proper Function from a Fuzzy Topological Space to another Fuzzy Topological Space
...Show More Authors

The purpose of this paper is to introduce and study the concepts of fuzzy generalized open sets, fuzzy generalized closed sets, generalized continuous fuzzy proper functions and prove results about these concepts.

View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Fme Transaction
The influence of frictional facing thickness on the contact pressure distribution of multi-disc dry clutches
...Show More Authors

Frictional heat is generated when the clutch starts to engag. As a result of this operation the surface temperature is increased rapidly due to the difference in speed between the driving and driven parts. The influence of the thickness of frictional facing on the distribution of the contact pressure of the multi-disc clutches has been investigated using a numerical approach (the finite element method). The analysis of contact problem has been carried out for a multiple disc dry clutch (piston, clutch discs, separators and pressure plate). The results present the distribution of the contact pressure on all tShe surfaces of friction discs that existed in the friction clutch system. Axisymmetric finite element models have been developed to ac

... Show More
View Publication
Scopus (9)
Crossref (9)
Scopus Clarivate Crossref
Publication Date
Thu Oct 01 2009
Journal Name
Iraqi Journal Of Physics
Effect of Glass Inclination of Windows Facing East and West on Solar Radiation Transmittance into Buildings
...Show More Authors

To reduce solar radiation transmittance into buildings through windows facing east or west during summer, a window inclination from vertical position is suggested. The inclination of the window glazing and the rate of unwanted solar radiation during summer can be calculated knowing the dialy inclination of the sun rays. The inclination of window glazing depends on the latitude of the position required. For instance in Baghdad which is at about 33o north latitude a slope of 15o for window glazing is sufficient to prevent about 419 MJ/m2 of total solar radiation energy from penetration during summer for clear glazing of window facing east. This value drops to about 96 MJ/m2 during winter. Therefore the ratio between the energy saved for co

... Show More
View Publication Preview PDF