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Medium access control protocol design for wireless communications and networks review
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<p><span>Medium access control (MAC) protocol design plays a crucial role to increase the performance of wireless communications and networks. The channel access mechanism is provided by MAC layer to share the medium by multiple stations. Different types of wireless networks have different design requirements such as throughput, delay, power consumption, fairness, reliability, and network density, therefore, MAC protocol for these networks must satisfy their requirements. In this work, we proposed two multiplexing methods for modern wireless networks: Massive multiple-input-multiple-output (MIMO) and power domain non-orthogonal multiple access (PD-NOMA). The first research method namely Massive MIMO uses a massive number of antenna elements to improve both spectral efficiency and energy efficiency. On the other hand, the second research method (PD-NOMA) allows multiple non-orthogonal signals to share the same orthogonal resources by allocating different power level for each station. PD-NOMA has a better spectral efficiency over the orthogonal multiple access methods. A review of previous works regarding the MAC design for different wireless networks is classified based on different categories. The main contribution of this research work is to show the importance of the MAC design with added optimal functionalities to improve the spectral and energy efficiencies of the wireless networks.</span></p>

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Publication Date
Sat Jan 01 2022
Journal Name
Journal Of The Mechanical Behavior Of Materials
Molding and simulation sedimentation process using finite difference method
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Abstract<p>The goal of this research is to develop a numerical model that can be used to simulate the sedimentation process under two scenarios: first, the flocculation unit is on duty, and second, the flocculation unit is out of commission. The general equation of flow and sediment transport were solved using the finite difference method, then coded using Matlab software. The result of this study was: the difference in removal efficiency between the coded model and operational model for each particle size dataset was very close, with a difference value of +3.01%, indicating that the model can be used to predict the removal efficiency of a rectangular sedimentation basin. The study also revealed</p> ... Show More
Publication Date
Mon Jun 17 2019
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Hard and Tough Epoxy Resins Modified with Thermosetting Materials
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Epoxy resins were modified by some thermosetting materials using unsaturated polyesters which were cured with styrene , MMA ,and MA . When unsaturated Polyester ( as thermosetting material ) was used , and cured with styrene showed better results than acrylic monomers . Thermal stability rised on modification of epoxy resins with unsaturated polyester . The new formulation had converted the epoxy resin from hard brittle material to hard and tough material .

Thermal analysis were studied using ( DSC ) and physicomechanical characteristics were measured .

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Publication Date
Sat Jan 09 2021
Journal Name
Medico Legal Update
Knowledge and Attitudes of Vaccination among Iraqi Pharmacy Students
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Objective: Since the vaccination rate is largely affected by low knowledge and negative attitudes ofhealthcare professionals, so this study aimed to weigh up the vaccination knowledge and attitudes ofpharmacy students.Method: A pilot study using a survey to investigate demographic data, knowledge (20 questions), andattitudes (5 questions) of 156 fifth year and 121 third year pharmacy students from College of Pharmacy/University of Baghdad.Results: The mean score of knowledge and attitudes was intermediate (16.654 and 14.917 out of 25 for thefifth and the third grades, respectively) with a significant difference between the two groups, the studentsshown to have favorable attitudes about vaccination. The score of the students is not i

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Publication Date
Wed Apr 19 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Corrosion and Corrosion Inhibition of α-Brass by Thiourea
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The corrosion behavior and corrosion inhibition of α-brass (65.3% Cu, 34.4% Zn and others 0.3%) in 0.6 mol.dm-3 NaCl solution have been investigated using potentiostatic polarization technique, the main results obtained were expressed in terms of corrosion (Ec) and corrosion current (ic). The research was performed in neutral and slightly acidic media [pH=7 and pH=4] over the temperature range (288-318)K. It was found that the rate of corrosion increases with the increase of acidity and the increase of temperature. The rate of corrosion increased with the increase of temperature in conformity with Arrhenius equation. Values of activation energy (Ea*), pre-exponential factor (A) and entropy of activation (∆S*) have been derived f

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Publication Date
Mon Apr 11 2022
Journal Name
Iraqi Journal Of Science
International Journal on Technical and Physical Problems of Engineering
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International Journal on Technical and Physical Problems of Engineering

Publication Date
Fri Mar 01 2019
Journal Name
Al-khwarizmi Engineering Journal
Comparison Study of Electromyography Using Wavelet and Neural Network
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In this paper we present a method to analyze five types with fifteen wavelet families for eighteen different EMG signals. A comparison study is also given to show performance of various families after modifying the results with back propagation Neural Network. This is actually will help the researchers with the first step of EMG analysis. Huge sets of results (more than 100 sets) are proposed and then classified to be discussed and reach the final.

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Publication Date
Thu Dec 29 2016
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Toxicological and Physiological Effects of DDT on Caenorhabditis elegans
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Toxicity assays were used in this study to test how DDT affects lethality and brood size of Caenorhabditis elegans (C.elegans) by exposing them to various concentrations of this agent. These nematodes have provided a very informative system that was utilized to study the behavioural and physiological processes. The results showed that DDT affected the lethality in a dose-dependent manner, but 100% kill was not achieved with concentration tested. Whereas, sodium azide, positive control does have an effect on C. elegans and significantly inhibiting lethality (LC50 0.01mM).  Similarly, DDT led to a pronounced effect in brood size of C.elegans compared to the mean brood size recorded for the control (0.1% DMSO). Sodium azide results sho

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Publication Date
Sat Oct 01 2022
Journal Name
Al–bahith Al–a'alami
TV planning and ways to deal with space developments
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The quote of a Canadian communication scientist (Marshall McLuhan) (“The world has become an electronic village”) has become an archaic information compared to the great and rapid development of communication in the last two decades of the 20th century and what will happen later in the 21st century, to the extent that the world is called, thanks to the internet, a “Small screen” and this fact is a sign of the great progress that has been made in this field. As for the other statement of the Canadian communication scientist mentioned before “the medium itself, is the message”, it has been renewed and developed in its meaning and it’s purpose. Each new technical development in the means of communication necessarily means a me

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Crossref
Publication Date
Wed Dec 30 2015
Journal Name
College Of Islamic Sciences
Morphological Participation in the Forms of (Faul) and (Fael)
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This research examines the phenomenon of the Arabic language repeated in the Qur'an and poetry, as some morphological formulas are valid in their uses and indications in more than one way. search).

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Publication Date
Thu Feb 07 2019
Journal Name
Journal Of The College Of Education For Women
Family violence: Causes and its effects - Analytical social study
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The aim of this study is to investigate the main causes of the family violence and its
social effects.
The study reveals that main factors causes of the violence are interaction between
multi-factors.
The study shows that the poverty, low educational level, house crowded, large family
size, all of these variables causes of the violence, and then causes of family disorganization
and juvenile delinquency.
The study contain of three sections:
First: Focused on the causes of the violence.
Second: The interaction between multi factors.
Third: Social effects of family violence.

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