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New Adaptive Data Transmission Scheme Over HF Radio
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Acceptable Bit Error rate can be maintained by adapting some of the design parameters such as modulation, symbol rate, constellation size, and transmit power according to the channel state.

An estimate of HF propagation effects can be used to design an adaptive data transmission system over HF link. The proposed system combines the well known Automatic Link Establishment (ALE) together with variable rate transmission system. The standard ALE is modified to suite the required goal of selecting the best carrier frequency (channel) for a given transmission. This is based on measuring SINAD (Signal plus Noise plus Distortion to Noise plus Distortion), RSL (Received Signal Level), multipath phase distortion and BER (Bit Error Rate) for each channel in the frequency list. Channel condition evaluation is done by two arrangements. In the first an FFT analysis is used where a pilot signal is transmitted over the channel, while the data itself is used in the second arrangement. Passive channel assessment is used to avoid bad channels hence limiting the frequency pool size to be used in the point to point communication and the time required for  scanning and linking. An exchange of channel information between the transmitting and receiving stations is considered to select the modulation scheme for transmission. Mainly MPSK and MFSK are considered with different levels giving different data rate according to the channel condition. The results of the computer simulation have shown that when transmitting at a fixed channel symbol rate of 1200 symbol/sec, the information rate ranges from 2400 bps using 4FSK up to 3600 bps using 8PSK for SNR ranges from 11dB up to 26dB.

 

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Publication Date
Sun Dec 04 2016
Journal Name
Baghdad Science Journal
Synthesis and Characterization of New 2-Quinolone Sulfonamide Derivatives
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A series of new 2-quinolone derivatives linked to benzene sulphonyl moieties were performed by many steps: the first step involved preparation of different coumarins (A1,A2) by condensation of different substituted phenols with ethyl acetoacetate. The compound A1 was treated with nitric acid to afford two isomers of nitrocoumarin derivatives (A3) and (A4). The prepared compounds (A2, A3) were treated with hydrazine hydrate to synthesize different 2-quinolone compounds (A5,A6) while the coumarin treated with different amines gave compounds (A7,A8). Then the synthesized 2-quinolone compounds (A5-A8) treated with benzene sulphonyl chloride to afford new sulfonamide derivatives (A9-A12). The synthesized compounds were characterized by FT-IR, 1H

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Publication Date
Thu Dec 01 2016
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
A NEW RECORD OF ZIZIPHORA SPECIES (LAMIACEAE) FOR IRAQ
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    Ziziphora persica Bunge is recorded as a new Study in Iraq. This species has been collected from Jabal Sinjar in Nineveh province in the north western part of Iraq. The morphological characters, habitat and geographical distribution of the species with a key to Ziziphora L. species in Iraq have been provided.

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Publication Date
Thu Mar 19 2020
Journal Name
Systematic Review Pharmacy
Synthesis and Biological Activity of Some New Thiazolidinone Derivatives
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The compound [G1] was prepared from the reaction of thiosemicarbazide with para-hydroxyphenylmethyl ketone in ethanol as a solvent. Then by sequence reactions prepared [G2] and [G3] compounds. The compound [G4] reaction with ethyl acetoacetoneto synthesized compound [G6] and acetyl acetone to synthesized compound [G5]. Reaction the [G3] with two different types of aldehydes in the present of pipredine to form new alkenes compounds [G7]and [G8].The compound [G3] reacted with hydrazine hydrate to formation[G4] with present the hydrazine hydrade 80% in (10) ml of absolute ethanol. Latter the compound [G4]reacted with different aldehydes with present the glacial acetic acid and the solvent was ethanol to formed the Schiff bases compounds[G9] an

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Publication Date
Mon Jul 01 2013
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
ZOOPHTHORA PHYTONOMI (ZYGOMYCETES: ENTOMOPHTHORACEAE) A NEW RECORD IN IRAQ
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    Morphological and phonological studies of fungal pathogen infecting alfalfa weevil Hypera postica (Gyllenhal) indicating that infection has been shown to develop along two distinct physiological lines, each culminating in the production of either conidial or resting spores, in host cadavers which are morphologically distinct. The percent of infection and epizootic development appeared to be dependent on host density. Farther evidence to entail proper correlation between conidia and resting spores suggest that these two forms of spores are stages in the development of one pathogen.

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Publication Date
Fri May 01 2020
Journal Name
Journal Of Physics: Conference Series
New Approach for Solving (1+1)-Dimensional Differential Equation
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Publication Date
Wed May 15 2013
Journal Name
Iraqi Journal Of Science
New record species- from the family Euphorbiaceae in Iraq
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Abstract The present work included morphological, anatomical, and palynological characters for the new species Acaalypha australis L. specimens, which belong to the family Euphorbiaceae. The species recorded in the study for the first time in Iraq. The plants of this species are annual herbs with green, striated or sub – polygonal stem, and branched near bases, Leaves are simple spirally alternate and lanceolate in shape. Flowers are unisexual, arranged in the axial of distinct leafy and cordate bracts, female flower arranged at the bracts bases and each flower with trileafed perianth and superior ovary with trilobed stylar stigma which has dense and coiled stigmatic hairs. Male flowers are arranged as a mixed verticellate inflorescence a

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Publication Date
Fri Dec 01 2023
Journal Name
Alexandria Engineering Journal
A new tilted aerial robotic platform: Modeling and control
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Publication Date
Sun Jun 02 2013
Journal Name
Baghdad Science Journal
Synthesis and Characterizationof Some New Phenolic Schiff Bases Derivatives
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Starting from bis (4,4'-diamino phenoxy) ethan(1), a variety of phenolicschiff bases (methylolic, etheric, epoxy) derivatives have been synthesized. All proposed structure were supported by FTIR, 1H-NMR, 13C-NMR Elemental analysis, some derivatives evaluated by thermal analysis (TGA).

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Publication Date
Sat Oct 27 2018
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
A NEW SPECIES OF CARABIDAE (NSECTA: COLEOPTERA) FROM IRAQ
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Aniera desert/cola was found new to science and to the Iraqi fauna. The description was
mainly based on external features and male genit

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Publication Date
Sun Jun 01 2014
Journal Name
University Of Baghdad
New Analytical Methods for Drugs Analysis A Comparative Study
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Four different spectrophotometric methods are used in this study for the determination of Sulfamethoxazole and sulfanilamide drugs in pharmaceutical compounds, synthetic samples, and in their pure forms. The work comprises four chapters which are shown in the following: Chapter One: Includes a brief for Ultraviolet-Visible (UV-VIS) Absorption spectroscopy, antibacterial drugs and sulfonamides with some methods for their determination. The chapter lists two methods for optimization; univariate method and multivariate method. The later includes different types, two of these were mentioned; simplex method and design of experiment method. Chapter Two: Includes reaction of the two studied drugs with sodium nitrite and hydrochloric acid for diazo

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