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Channel Estimation and Prediction Based Adaptive Wireless Communication Systems
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Wireless channels are typically much more noisy than wired links and subjected to fading due to multipath  propagation which result in ISI and hence high error rate. Adaptive modulation is a powerful technique to improve the tradeoff between spectral efficiency and Bit Error Rate (BER). In order to adjust the transmission rate, channel state information (CSI) is required at the transmitter side.

In this paper the performance enhancement of using linear prediction along with channel estimation to track the channel variations and adaptive modulation were examined. The simulation results shows that the channel estimation is sufficient for low Doppler frequency shifts (<30 Hz), while channel prediction is much more suited at high Doppler shifts with same SNR and target BER=10-4. It was shown that the performance at higher Doppler frequency shifts (<30Hz) was improved by more than 2dB over channel estimation at target BER=10-4 and 32QAM constellation used.

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Publication Date
Tue Oct 09 2018
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
A COMPARATIVE HISTOLOGICAL STUDY OF THYROID TISSUE IN CARP FISH CYPRINUS CARPSIO AND MICE SWISS ALBICANS
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    This histological study was carried out to compare between the thyroid gland of mice (as a model of the mammals) and the thyroid tissue of fish.  Unlike mice, the thyroid gland of fish can't be recognized by naked eye.  The present study revealed that the thyroid of mice varied from that of fish by the location and the histological structure. The study classified the physiological state of the thyroid of mice into three states and that of the fish into only two states. Accordingly, the study concluded that the metabolism of thyroid fish was of moderate type.

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Publication Date
Thu Dec 26 2019
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
THE EFFECTS OF TEMPERATURE AND MOISTURE STRESS CONTENT ON THE EXTENSIVE CULTIVATION OF THE OYSTER MUSHROOM
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    Oyster mushroom (Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm.) is involved in the destruction of dead wood which is the main place of settlement of several living organisms. After humification, dead wood also becomes an important component of forest soils.

 

    The purpose of the research is to study temperature and moisture conditions of extensive cultivation of oyster mushrooms on various wood substrates. To accomplish this goal, the following tasks were set: to determine the amount of effective stress temperatures and moisture content of substrates and their influence on the appearance of fruiting bodies of the oyster mushroom; to study the features of the extensive culti

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Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
Spectrophotometric Determination of Vancomycin Hydrochloride (Batch and Flow-Injection) Using O-Nitroaniline as diazotized Chromogenic Reagent
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New, simple and sensitive batch and nFIA spectrophotometric methods for the determination of Vancomycin Hydrochloride in pure form and in pharmaceutical preparations were proposed, These method's were based on diazotization and coupling reaction between Vancomycin Hydrochloride and diazotized O-nitroaniline in alkaline medium to form Orange water-soluble dye that is stable and has a maximum absorbance at 465nm. Acalibration graph shows that aBeer's law is obeyed over the concentration range of 0.8-60 and 5-400 μg.mL-1 of Vancomycin Hydrochloride with detection limit's of 0.16 and 1.666 μg.mL-1 of Vancomycin Hydrochloride for batch and nFIA methods, respectively. The FIA procedure sample throughput was 80 h-1. All different chemicals an

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Publication Date
Wed Apr 19 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Study the Effect of Zn Doping in the Structural and Electrical Properties of CdTe Thin Films
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Some of structural ,and electrical properties of pure and zinc (Zn) doped cadmium telluride thin films with impurity percentages (0.5, 1, 1.5)%, deposited on hot glass substrate (temperature equals to 423K) of  thickness of 300nm and rate deposition of 0.5 nm.s-1  by thermal co-evaporation technique under vacuum of (2×10-5)Torr have been investigates. The structural properties for the prepared films were studied before and after. doping process by analysis of the X-ray diffraction, and it appeared that pure and dopant  CdTe thin films are polycrystalline and have the cubic structure with preferential orientation in the [111] direction, and the crystal structure of the films were improved due to doping process. From d.c

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Publication Date
Sun Apr 30 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Study Of Optimum Conditions For The Removal Of Ruthenium And Cerium Using Freshly Prepared Manganese Dioxide
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 The adsorption of Ru and Ce were carried out using manganese dioxide as adsorbent. The Optimization of the adsorption conditions were studied as a function of shaking time, nitric acid, metal ions, concentrations and temperature effects.      A rapid initial adsorption on MnO2 is followed by a steady and slow increase of metal uptake. The equilibration time is reached after four hours shaking for Ru and Ce and    the adsorption is much better from one molar acidic solution and 90°C.

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Publication Date
Wed Dec 25 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Non-interest income and its impact on the profits of the Iraqi banking sector: (Comparative study)
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     In this study,  has been discussed the issue of non-interest income and its impact on the Iraqi banking sector profit for the period between (2008-2017) as it was the main objective of the study is to find the relationship between the non-interest income and the profits of the banking sector in order to know  the size of the sector's dependence on non-interest income As well as an analysis of its profitability compared to selected countries, And to test hypotheses, the financial ratios and some statistical tests to determine the stability of the time series such as the test (Correlegram , Dickey -Fuller (depending on the statistical program (E-Views V8) and a simple linear regression method by (Minitab

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Publication Date
Wed Mar 29 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
Development and in vitro Evaluation of Bioadhesive Vaginal Tablet using Econazole Nitrate as a Model Drug
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         In this study, a bioadhesive dosage form of eoconazole nitrate for vaginal delivery was designed using a combination of bioadhesive polymers: Carbopol 941 p and sodium carboxymethylcellulose or methylcellulose in different ratios. The bioadhesive strength was evaluated by measuring the force required to detach the tablet from sheep vaginal mucosal membrane. It was found that the bioadhesive force was directly proportional to Carbopol 941 p content in the different formulae. The formulae were tested for their swelling behavior using agar gel plate method. The results showed that formulae containing a combination of Carbopol 941 p and sodium carboxymethylcellulose had greater swelling index

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Publication Date
Fri Mar 01 2019
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study of Drug Delivery system for Prednisolone Loaded and Released by Mesoporous Silica MCM-41
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In the present study, nanoporous material type MCM-41 was prepared by the sol-gel technique and was used as a carrier for prednisolone (PRD) drug delivery. The structural properties of mesoporous were fully characterized by X-ray diffraction (XRD), N2 adsorption /desorption and Fourier-transform infrared (FTIR). The mass transfer in term of adsorption process (loading) and desorption process (releasing) properties were investigated. The maximum drug loading efficiency was equal to 38% and 47.5% at different concentrations. The PRD released was prudently studied in water media of pH 6.8 simulated body fluid (SBF) in according to "United State Pharmacopeia (USP38)". The results proved that the release of prednisolone from MCM-41

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Publication Date
Thu Mar 09 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis, Spectroscopic and Adsorption Studies of Cobalt (II) Complex for a ligand β-enaminone Derived from
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   This paper concerns is the preparation and characterization of a bidentate ligand [4-(5,5dimethyl-3-oxocyclohex-1-enylamino)-N-(5-methylisoxazol-3-yl) benzene sulfonamide].  The ligand was prepared from fusing of sulfamethoxazole and dimedone at (140) ºC for half hour.              The complex was prepared by refluxing the ligand with a bivalent cobalt ion using ethanol as a solvent. The prepared ligand and complex were identified using Spectroscopic methods. The proposed tetrahedral geometry around the metal ions studied were concluded from these measurements. Both molar ratio and continuous variation method were studied to determine metal to ligand ratio (M:L). The M to L ratio wa

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Publication Date
Wed Jul 29 2020
Journal Name
Iraqi Journal Of Science
High AdiponectinHormone Modulation ofBlood Erythroid Parameters and its Relation with Erythropoietin in Patients with Diabetic Nephropathy
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Background: Serum adiponectin is a hormone of adipose tissue that activateslipid metabolism and exertsphysiological functions. Its level usually fluctuates in several metabolic diseases,including renal insufficiency and diabetes; it loses its protective role against diseases and becomes a potentially risk factor for erythroid abnormalities.

Objectives: The study was designed to assess the association between adiponectin  hormone, blood erythroid and various parameters in groups of patients.

Method:The study included 130 patientsand 42 healthy subjects. Parameters of serum adiponectin, erythropoietin (EPO), red blood cells (RBC), hemoglobin (Hb), hematocrit (Hct), ren

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