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Power Efficiency Maximization in Cognitive Radio Networks
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Cognitive radio technology is used to improve spectrum efficiency by having the cognitive radios act as secondary users to access primary frequency bands when they are not currently being used. In general conditions, cognitive secondary users are mobile nodes powered by battery and consuming power is one of the most important problem that facing cognitive networks; therefore, the power consumption is considered as a main constraint. In this paper, we study the performance of cognitive radio networks considering the sensing parameters as well as power constraint. The power constraint is integrated into the objective function named power efficiency which is a combination of the main system parameters of the cognitive network. We prove the existence of optimal combination of parameters such that the power efficiency is maximized. Then we reformulate the objective function to incorporate the throughput. According to different constraints or degree of significance, we may put proper weight to each term so that we could obtain more preferable combination of parameters. Computer simulations have given the optimal solution curve for different weights. We can draw the conclusion that if we put more emphasis on power efficiency, the transmit power is a more critical parameter, however if throughput is more important, the effect of sensing time is significant.

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Publication Date
Sun Jun 04 2017
Journal Name
Baghdad Science Journal
Levels of Serum Lipid profile and Kidney Function Tests in Iraqi Hypertensive Patients: Duration Effect Study
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Hypertension is one of the leading causes of the global burden of disease, which causes serious health problems. The aim of this study is to investigate the lipid profile levels in sera of Iraqi hypertensive patients by measuring Total cholesterol (TC), triglyceride (TG) and low density lipoproteins (LDL) and kidney function levels by measuring uric acid, urea and creatinine. Seventy five individuals of Iraqi adults (Males) were divided into three groups: 25 hypertensive patients with duration of disease (1-10) year (group 1), 25 hypertensive patients with duration of disease (11-30) year (group 2) and 25 normal individuals as control group (group3). The findings indicate that serum (TC, TG and LDL) levels were significantly elevated (

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Publication Date
Sun Jun 01 2025
Journal Name
Journal Of Physics: Conference Series
Studying the properties of linearly polarized modes in step index optical fibers at 1030 nm wavelength
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Abstract<p>The growing demand for optical fibers is due to their superior the ability to transmit information with high efficiency and minimal loss across extensive distances. In this study, four optical fibers with core radii ranging from (2.05-5.05) μm, and with a numerical aperture of 0.1624 were analyzed. The modal properties of these fibers were calculated at a wavelength of 1030 nm using the RP Fiber Calculator software (free version 2025). Furthermore, the impact of increasing the core radius on these properties was examined. The results showed that multimode fibers are formed when the core radius is much larger than the wavelength used. In contrast, single-mode fiber is obtained when th</p> ... Show More
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Publication Date
Thu Feb 16 2023
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Phytosterol Profile in Iraqi Lactuca serriola after Purification and Isolation by Combiflash and HPLC (Conference Paper )#
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One of these plants utilized in traditional medicine is Lactuca seriolla Linn., which belongs to the Asteraceae family. It goes by a variety of common names in the world, including prickly lettuce, wild lettuce, jagged lettuce, and Kahu and khas. The work aimed to isolate and characterize some bioactive constituent(s) from the aerial part of Lactuca serriola utilizing  Combiflash NEXTGEN and high-performance liquid chromatography (HPLC). Lactuca serriola (aerial part) was extracted with 80% ethanol, then fractionated with hexane. Then 250 mg of hexane extract was mixed with 4 g of silica gel and loaded in cartilage, then bounded to the gold column of combi flash using a solvent system comprised of ethyl acetat

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Publication Date
Sat Jun 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
A field study of the problems of queues at some checkpoints in the city of Baghdad
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Abstract

Due to the momentum of winning in the streets of the city of Baghdad as a result of the large number of checkpoints so felt researcher to conduct a field visit to find out the main reasons that led to this congestion and to find practical solutions to mitigate wastage winning the arrival time citizen to where you want the least possible time.

This research aims to overcome the difficulties experienced by citizens to reach their places of work and reduce waste at the time of service and waiting time as well as reduce the cost of waiting.

Has emerged study a set of conclusions, including the use of model queue (G / G / C) and the mome

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Publication Date
Sun Mar 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
Identify the main factors affecting labor productivity within different organizational structures in the Iraqi construction sector
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Abstract<p>The construction sector in Iraq has faced many challenges. One of the major challenges is the lack of productivity of laborers who are working construction sites. Although research studies have been conducted to investigate, explore, and identify factors influencing labor productivity in the Middle-east region, the lack of such research studies to address these challenges in Iraq. This motivates the researcher to explore and identify the key factors affecting labor productivity in construction sites across different organizational structures (Matrix, Projectized, and functional). A survey questionnaire has been conducted using Delphi technique in order to achieve a concrete and reliab</p> ... Show More
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Publication Date
Fri Jun 01 2018
Journal Name
Journal Of The College Of Languages (jcl)
ביטויים של אהבה ושנאה בטקסטים של חמשה חומשי התורה Expressions of Love and Hatred in Pentateuch
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תקציר

     ביטויי אהבה ושנאה קבלה בההגדרות שונות, לפעמים ביניהם לבין עצמם והסכימו בזמנים אחרים מהבחינה הדתית נתפסה לאהוב ביטויים ושנאה במונחים של טוב ורע, או במונחים של חלאל וחראם למעשה, הרגשות של אהבה ושנאה הם רגשות אנושיים המקושרים לאמונות של חברות אנושיות הבנויות על העמדה של דתות מכל נושא או מקרה  , דבר אשר אהוב על ידי הקדושים והכמורה יהיה חלאל, וכל מה שהם שונאים יהיה חראם במילים אח

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Publication Date
Sun Feb 10 2019
Journal Name
Iraqi Journal Of Physics
Experimental study for the properties of Fe3O4 dusty plasma using the air in vacuum chamber system
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In this work, we carried out an experimental study of thedusty
plasma by taking the dust material Fe3O4 with radius of the any grain
0.1μm - 0.5μm. In experiment we use air in the vacuum chamber
system under different low pressure (0.1-1) Torr. The results
illustrated that the present of dust particles in the air plasma did not
effect on Paschen minimum which is 0.5 without dust and with Fe3O4
dusty grains.
The effect of Fe3O4 dust particles on plasma parameters can be
notice in direct current system in glow discharge region. The plasma
parameters which were studied in this work represent plasma
potential, floating potential,electron saturation current, temperatu

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Publication Date
Sat Apr 01 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
In Vitro Release Study on Capsules and Tablets Containing Enteric - Coated Granules Prepared by Wet Granulation
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Wet granulation method was used instead of conventional pan coating  or fluidized –bed coating technique to prepare enteric-coated diclofenac sodium granules, using ethanolic solution of EudragitTM L100 as coating, binding and granulating agent .Addition of PEG400 or di-n-butyl phthalate as a plasticizer was found to improve the enteric property of the coat.

Part of the resulted granules was filled in hard gelatin capsules (size 0), while the other part was compressed into tablets with and without disintegrant.

The release profile of these two dosage forms in 0.1N HCl (pH 1.2)for 2 hours, and in phosphate buffer (pH 6.8) for 45 minutes as well as the release kinetic were compared with that of the en

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Publication Date
Tue Mar 28 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Association of Admission Serum Resistin Level with Acute ST-Segment Elevation Myocardial Infarction in Iraqi Patients
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Human resistin is an adipokine, with a possible link to coronary heart disease.A few studies were done about resistin in acute phase of ST-segment elevation myocardial infarction (STEMI) especially in Iraqi patients. Accordingly we design a study to investigate the association between resistin concentration and acute phase of STEMI in Iraqi patients.

The present study was carried out at Al-Yarmouk Teaching Hospital from December 2011 until June 2012. Serum resistin levels were measured in 50 patients with acute STEMI (mean age: 58.16 ± 11.73 years) at the first 12 hours of admission and 34 normal controls (mean age: 53.98 ± 15.46 years) matched for age, sex and other risk factors.

 Resistin level in patients wi

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Publication Date
Sun Oct 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
THE IMPACT OF CURRENCY AUCTION ON THE VARIABILITY OF THE EXCHANGE RATE IN IRAQ 2004-2015
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The transition states that Iraq economy lived it after 2003, and the change in tools used by monetary policy based on C.B.I law 56 in 2004, under the especially situation for the economy (structural imbalances and the weakness of banking & financial sector).

The monetary policy adopted the inflation targeting policy to mantain the monetary stability in the economy and considered it an incubator for future growth. It used the exchange rate as a nominal anchor to achieve the goal (because the rentier of economy, finance Shallowness & separation between real sector and finance sector, all this cause the normal channel to transfer the effect of monetary policy (interest rate) ineffective.

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