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alkej-590
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
Fri Jun 01 2012
Journal Name
Journal Of Engineering
New Correlation To Calculate Absolute Permeability From Gas Permeameter
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In this study, two correlations are developed to calculate absolute rocks permeability from core samples tested by Gas Permeameter Apparatus. The first correlation can be applied if K g≤100, the second correlation can be applied if Kg>100. Sixty core samples having different permeabilities to give a wide range of values that necessary to achieve a correlation.

 

The developed correlation is easily applied and a quick method to avoid repeating the test at different pressure values. Only one pressure test is required to reach absolu

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Publication Date
Tue Jun 11 2019
Journal Name
Opicion
Assessing Students’ College of the Physical Education and Sport Sciences’ Level of Performance in English in Terms the New Prescribed Textbook “New Headway plus”
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Publication Date
Wed Jul 09 2025
Journal Name
Applied Organometallic Chemistry
Evaluation of Anticancer and Antioxidant Activity of New Metal Ions Fe(III), Co(II), Ru(III), and Rh(III) Complexes With New Azo Dye
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The azo dye (LH) was used to synthesize a series of complexes with Fe(III), Co(II), Ru(III), and Rh(III) metal ions. The ligand (LH) was synthesized by the condensation reaction between tryptamine and 2-hydroxyquinoline. Due to the presence of effective donor atoms (-N=N- azo and OH hydroxyl groups), the ligand was subsequently refluxed with various metal ions, leading to the formation of nonelectrolytic [M:L] (1:2). These compounds were characterized using 1H and 13C-NMR, FT-IR, UV–Vis, mass spectrometry, TGA, DSC, and C.H.N. analysis, along with conductivity, magnetic susceptibility, and metal and chlorine content measurements. The results indicated that the ligand acts as a bidentate, with the complexes adopting an octahedral geometry.

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Publication Date
Wed Jun 30 2021
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
SYNTHESIS OF NEW LEVOFLOXACIN SELECTIVE MEMBRANE SENSOR BASED ON MOLECULARLY IMPRINTED POLYMERS.: SYNTHESIS OF NEW LEVOFLOXACIN SELECTIVE MEMBRANE SENSOR BASED ON MOLECULARLY IMPRINTED POLYMERS.
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Two molecular imprinted polymer (MIP) membranes for Levofloxacin (LEV) were prepared based on PVC matrix. The imprinted polymers were prepared by polymerization of styrene (STY) as monomer, N,N methylene di acrylamide as a cross linker ,benzoyl peroxide (BPO) as an initiator and levofloxacin as a template. Di methyl adepate (DMA) and acetophenone (AOPH) were used as plasticizers , the molecular imprinted membranes and the non molecular imprinted membranes were prepared.  The slopes and detection limits of the liquid electrodes ranged from -21.96 – -19.38 mV/decade and 2×10-4M- 4×10-4M, and Its response time was around 1 minute, respectively. The liquid  electrodes were packed with 0.1 M standar

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Publication Date
Tue Dec 05 2023
Journal Name
Baghdad Science Journal
Ecofriendly Control for Stored-Product Pest, Oryzaephilus surinamensis (Order: Coleoptera, Family: Silvanidae)
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Dates are considered one of the most important foods consumed in Arab countries. Dates are commonly infested with the sawtoothed grain beetle, Oryzaephilus surinamensis. Consequently, the date yield, quantity, and quality (economic value and seed viability) are negatively affected. This study was designed to investigate the effectiveness of air evacuation as eco-friendly and safe control method against adult O. surinamensis. Insects were obtained from the infested date purchased from a private store in sakaka city, Aljouf region, Saudi Arabia. Air evacuation (using a vacuum pump) and food deprivation were applied to O. surinamensis, and insect mortality was observed daily in comparison with the control group (a

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Publication Date
Sun Dec 01 2019
Journal Name
Baghdad Science Journal
Studying the Crystal Structure, Topography, and Anti-bacterial of a Novel Titania (TiO2 NPs) Prepared by a Sol-gel Manner
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In this research, titanium dioxide nanoparticles (TiO2 NPs) were prepared through the sol-gel process at an acidic medium (pH3).TiO2 nanoparticles were prepared from titanium trichloride (TiCl3) as a precursor with Ammonium hydroxide (NH4OH) with 1:3 ratio at 50 °C. The resulting gel was dried at 70 °C to obtain the Nanocrystalline powder. The powder from the drying process was treated thermally at temperatures 500 °C and 700 °C. The crystalline structure, surface morphology, and particle size were studied by using X-ray diffraction (XRD), Atomic Force Microscopy (AFM), and Scanning Electron Microscope (SEM). The results showed (anatase) phase of titanium dioxide with the average grain size

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Publication Date
Fri Dec 01 2006
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
اعتماد طريقة جمع المصالح ضرورة لتطوير الجانب المنطقي لمعيار الإبلاغ المالي الدولي رقم 3 (اندماج الأعمال)
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اندماجات الأعمال من المظاهر الطبيعية في غالبية دول العالم، ورغم المنافع الكثيرة لاندماجات الأعمال إلا أن المخاطر التي تنتج منها أدت إلى تعقد الإجراءات القانونية لتنفيذها بشكل كبير، كما تعد المعالجة المحاسبية للاندماج من القضايا المعقدة جداً وتثير جدلاً واسعاً في الفكر المحاسبي لا سيما في ظل وجود مدخلين يؤثران في متضمنات المعالجة المحاسبية للاندماج أولهما المدخل القانوني الذي يقسم الاندماج إلى ثلاثة أشك

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Publication Date
Fri Sep 30 2011
Journal Name
Al-khwarizmi Engineering Journal
Analysis of Temperature and Residual Stress Distribution in CO2 Laser Welded Aluminum 6061 Plates Using FEM
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This paper develops a nonlinear transient three-dimensional heat transfer finite element model and a rate independent three-dimensional deformation model, developed for the CO2 laser welding simulations in Al-6061-T6 alloy. Simulations are performed using an indirect coupled thermal-structural method for the process of welding. Temperature-dependent thermal properties of Al-6061-T6, effect of latent heat of fusion, and the convective and radiative boundary conditions are included in the model. The heat input to the model is assumed to be a Gaussian heat source. The finite element code ANSYS12, along with a few FORTRAN subroutines, are employed to obtain the numerical results. The benefit of the proposed methodology is that it

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Publication Date
Mon May 01 2006
Journal Name
أثر استعمال طريقة التعلم التعاوني في تحصيل طلاب الصف الخامس الأدبي في مادة قــواعــد اللغــة العربيـــة
أثر استعمال طريقة التعلم التعاوني في تحصيل طلاب الصف الخامس الأدبي في مادة قــواعــد اللغــة العربيـــة
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Publication Date
Thu Nov 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
Estimate size sub-population by Killworth method
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The aim of the thesis is to estimate the partial and inaccessible population groups, which is a field study to estimate the number of drug’s users in the Baghdad governorate for males who are (15-60) years old.

Because of the absence of data approved by government institutions, as well as the difficulty of estimating the numbers of these people from the traditional survey, in which the respondent expresses himself or his family members in some cases. In these challenges, the NSUM Network Scale-Up Method Is mainly based on asking respondents about the number of people they know in their network of drug addicts.

Based on this principle, a statistical questionnaire was designed to

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