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
Wed Mar 30 2022
Journal Name
Gsc Biological And Pharmaceutical Sciences
Using the silicon (luminal cast plastination technique) for the lower respiratory tract in sheep as an alternative to cement
...Show More Authors

The lower respiratory tract of sheep was studied to determine the torsion and branching of the bronchial tree. The respiratory system of ruminants and all living organisms is one of the most important organs in the body that controls the amount of gas exchange between the heart and lungs through the airways, it is clear that in sheep it consists of a narrow bronchial tube that reaches the extent of lung tissue repercussions. He used silicon, water, acid, and at room temperature, and the substance was injected with an injection gun through the trachea and was pushed gently to spread and distribute in all parts of the lungs with moderate manual pressure. The results showed that the mold shape in the lung and the bronchial branches of

... Show More
View Publication
Crossref
Publication Date
Mon Apr 03 2023
Journal Name
Journal Of Educational And Psychological Researches
The Effectiveness of Using Cubing Technique in the Iraqi EFL Secondary Students' Composition Writing, Vocabulary, and Meta-Cognitive Awareness
...Show More Authors

Abstract

The aim of this research is to determine how well the Cubing Technique affects the Iraqi EFL students' composition writing, vocabulary, and meta-cognitive awareness of writing strategies. The sample of (64) secondary-school female students in the fifth grade is drawn from two classrooms and split into two equal groups: the experimental group and the control group, each of which consists of (32) students. A quasi-experimental design is applied. The performance test and Meta-cognitive Writing Strategies questionnaire are given as a pre-test for equalizing the two groups after ensuring their validity and reliability. Then, they are administrated as a posttest in both groups. According to the results, the si

... Show More
View Publication Preview PDF
Publication Date
Sun Apr 30 2023
Journal Name
Al-kindy College Medical Journal
The Surgical outcomes of fundus-first technique in lowering the rate of bile duct injuries and bleeding during open cholecystectomy that facing intraoperative difficulties: A single-center prospective study: The surgical outcomes of open fundus-first cholecystectomy technique.
...Show More Authors

Background: The problem of difficult gallbladder is not clearly defined and associated with real missing of therapeutic approaches that decreased morbidity. Moreover, the difficult gallbladder was reported as a contributing risk factor for biliary injury due to raised difficulty in surgical dissection within Calot’s triangle. The aim of this study is to determine the surgical outcomes of the open fundus-first cholecystectomy in lowering the rate of lethal intraoperative risks.

Subjects and Methods: Our prospective study conducted during the period of January 2019 to December 2022 at Ibn Sina specialized hospital, Khartoum, Sudan, for two hundred and fifty-three patients underw

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Crossref
Publication Date
Fri Jul 01 2022
Journal Name
Rawal Medical Journal
Macular thickness correlation with gender and age in a sample of healthy eyes of Iraqi population utilizing optical coherence tomography
...Show More Authors

Preview PDF
Scopus (1)
Scopus
Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
The Study of properties structure and some optical properties forcopper Oxid (CuO) Thin film prepared by thermal evaporation in Vacume
...Show More Authors

in this paper copper oxide (cuO thin films were prepared by the method of vacum thermal evaporation a pressure.

View Publication Preview PDF
Publication Date
Tue May 01 2012
Journal Name
Iraqi Journal Of Physics
Structural and optical properties of BaTiO3 thin films prepared by pulsed laser deposition
...Show More Authors

BaTiO3 thin films have been deposited on Si (111) and glass substrates by using pulsed laser deposition technique. The films were characterized by using X-ray diffraction, atomic force microscope and optical transmission spectra. The films growth on Si after annealing at 873K showed a polycrystalline nature, and exhibited tetragonal structure, while on glass substrate no growth was noticed at that temperature. UV-VIS transmittance measurements showed that the films are highly transparent in the visible wavelength region and near-infrared region for sample annealing on glass substrate. The optical gap of the film were calculated from the curve of absorption coefficient (αhν) 2 vs. hν and was found tobe 3.6 eV at substrate temperature 5

... Show More
View Publication Preview PDF
Publication Date
Fri Jul 28 2017
Journal Name
Iraqi Journal Of Science
Morphological and Optical Properties of CdS Quantum Dots Synthesized with different pH values
...Show More Authors

View Publication
Crossref
Publication Date
Fri Jan 01 2010
Journal Name
Advances In Condensed Matter Physics
Electrical and Optical Properties of :H Thin Films Prepared by Thermal Evaporation Method
...Show More Authors

Thin a-:H films were grown successfully by fabrication of designated ingot followed by evaporation onto glass slides. A range of growth conditions, Ge contents, dopant concentration (Al and As), and substrate temperature, were employed. Stoichiometry of the thin films composition was confirmed using standard surface techniques. The structure of all films was amorphous. Film composition and deposition parameters were investigated for their bearing on film electrical and optical properties. More than one transport mechanism is indicated. It was observed that increasing substrate temperature, Ge contents, and dopant concentration lead to a decrease in the optical energy gap of those films. The role of the deposition conditions on value

... Show More
View Publication
Scopus (2)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Fri Apr 21 2023
Journal Name
Technologies And Materials For Renewable Energy, Environment And Sustainability: Tmrees22fr
Calculating the modes properties for glass optical fibers at He-Ne laser wavelength
...Show More Authors

View Publication
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Wed Mar 10 2021
Journal Name
Baghdad Science Journal
Theoretical Studies of Sum Optical Properties for InAs (001) by Surface Differential Reflectivity
...Show More Authors

The real and imaginary part of complex dielectric constant for InAs(001) by adsorption of oxsagen atoms has been calculated, using numerical analysis method (non-linear least square fitting). As a result a mathematical model built-up and the final result show a fairly good agreement with other genuine published works.

View Publication Preview PDF
Crossref