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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
Fri Nov 24 2023
Journal Name
Iraqi Journal Of Science
Effect of Two Species of Cyanobacteria as Biofertilizers on Characteristics and Yield of Chickpea Plant
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The cyanobacteria strains were used in bioreactors to produce biomass. The total biomass after one month in suitable conditions such as efficient gas exchange, powerful light source and suitable medium composition was 7.99 mg/ml for N. commune and 5.83mg/ml for A. circinalis. These algae were applied alone or mixed in two rates (5 or 10 ml/ 100 g compost); Azotobacter chroococcum was used before 7 days of harvesting or with other cyanobacteria species. The total Nitrogen showed 1.84% with Azotobacter, however the nitrogen in mix culture was 1.80% mean while, the control treatment was 1.49%.. These results indicate that we can reduce chemical fertilizers by 1/4 or may 1/2 dose of normal requirement on growth and yield of chickpea plant.

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Publication Date
Wed Sep 30 2015
Journal Name
College Of Islamic Sciences
Preservation of the mind and its development Makassedi study in the light of prayers Almathur
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A great abbey in the Shari'a, and is therefore destined to be preserved in many texts and by methods
There are many prayers in the Qur'an and Sunnah to encourage them
They have a clear relationship with the preservation of the purposes of the Sharia in general, and with a purpose
Save the mind in particular, but the scholars - the mercy of God - when they declare that the costs of Sharia
Due to the preservation of my intentions in the creature, they limit their words to orders and intentions, and are not exposed
In particular,
If they were included in the texts of the Shariah and Tawjiyatiya,
To be related to the preservation of the purposes of the law, which confirms the words of the former leaders, and light the li

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Publication Date
Sun Mar 13 2011
Journal Name
Baghdad Science Journal
Study of character and diversity of vegetation (cultivated plants) in Al-aaras Tourst Island / Baghdad
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Vascular plants that have been identified during the study seasons in the Island. The cultivated plants were 126 species belong to 103 genera and to 49 families of the year 2001-2002 . The natural vegetation in this Island has been subjected to a total disturbance and subsidence due to the comprehensive turbidity of the Island environment.Number of names of that natural vegetation has been mentioned in the study within the weed plants.The results of the study of the period of flowering and their attitudes show clear seasonal differences. During the cold months of winter, the number of the cultivated and the natural plants was at the rate of 15%.These kinds of flowers require high level of care to increase their numbers. While in the spring

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Crossref
Publication Date
Fri Sep 27 2019
Journal Name
Journal Of Baghdad College Of Dentistry
The role of prophylactic antibiotics in compound facial fractures treated by closed and open reduction
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Background: The role of prophylactic antibiotics remains controversial. It is clear that actively facial fractures are considered as clean contaminated and should be treated with therapeutic antibiotics; however, there is widespread variability in the use, type, timing, and duration of prophylactic antibiotic administrated in practice today. There is an adverse effect of increased antibiotic resistance, as well as costs, it is important to review the current evidence for the role of prophylactic antibiotics in compound facial fractures. The purpose of this study is to evaluate the role and significance of preoperative, perioperative and postoperative antibiotic prophylaxis for patients when there is already an infective focus, such as co

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Scopus Crossref
Publication Date
Sun Sep 05 2010
Journal Name
Baghdad Science Journal
Detection of interleukin-6 and interleukin-8 in serum from women with recurrent spontaneous abortion
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To investigate the role of IL-6 and IL-8 in the immune-regulatory mechanisms involved in the recurrent spontaneous abortion of the first trimester of pregnancy. Serum level of IL-6 and IL-8 were determined in 25 women of age (20-35) years who had a spontaneous abortion of unknown aetiology during the first trimester of pregnancy .They were compared with the corresponding levels of 20 pregnant and non-pregnant women as control groups .cytokine levels were measured by (ELISA) technique .The women with spontaneous abortion had highly significant (P < 0.01) increased serum level of IL-8 and highly significant (P < 0.01 ) decreased level of IL-6 compared to those with normal pregnant and non-pregnant women. The results of this study ma

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Crossref
Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
Transfocation Technique to Overcome Atmospheric Scintillation Effect on a Laser Detection and Tracking System (LDTS)
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Atmospheric transmission is disturbed by scintillation, where scintillation caused more beam divergence. In this work target image spot radius was calculated in presence of atmospheric scintillation. The calculation depend on few relevant equation based on atmospheric parameter (for Middle East), tracking range, expansion ratio of applied beam expander's, receiving unit lens F-number, and the laser wavelength besides photodetector parameter. At maximum target range Rmax =20 km, target image radius is at its maximum Rs=0.4 mm. As the range decreases spot radius decreases too, until the range reaches limit (4 km) at which target image spot radius at its minimum value (0.22 mm). Then as the range decreases, spot radius increases due to geom

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Publication Date
Mon Mar 31 2014
Journal Name
Al-khwarizmi Engineering Journal
Corrosion Behavior of V2AlC and Cr2AlC Compared with SS 316L in NaOH at Four Temperatures
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Abstract

      This work involves the manufacturing of MAX phase materials include V2AlC and Cr2AlC using powder metallurgy as a new class of materials which characterized by regular crystals in lattice. Corrosion behavior of these materials was investigated by Potentiostat to estimate corrosion resistance and compared with the most resistant material represented by SS 316L. The experiments were carried out in 0.01N of NaOH solution at four temperatures in the range of 30–60oC. Polarization resistance values which calculated by Stern-Geary equation indicated that the MAX phase materials more resistant than SS 316L. Also cyclic polarization tests confirme

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Publication Date
Sun Oct 06 2013
Journal Name
Journal Of Educational And Psychological Researches
Following model educational offenders in collection and Alasbaka of fifth grade students preparatory in history
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Following model educational offenders in collection and Alasbaka of fifth grade students preparatory in history A. M. Dr Prepared by: Dr. Bashaer Mawloud Tawfeeq, The Center of Educational and Psychological Studies Baghdad University - There is no difference statistically significant at the 0.05 level of significance between the average scores of the following students studying using model and offenders and who are studying in the usual manner (traditional) in the collection - There is no difference statistically significant at the 0.05 level of significance between the mean scores for the following students studying using model and offenders and who are studying in the usual manner (traditional) in retention Find limits: Current search

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Publication Date
Tue Dec 11 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Disease Patterns and outcomes of Neonatal Admissions at Raparin Pediatric Teaching Hospital in Erbil City
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Objectives: This study aims to determine the disease’s patterns and outcomes of admission among neonates hospitalized at the neonatal care unit in Erbil City, and using the findings as a baseline for neonate’s morbidity and mortality assessment in the future. Methodology: A retrospective study carried out at neonatal care unit of Raparin pediatric teaching hospital. An instrument for data collection developed by researcher included (age, gender, cause of admission, diagnosis and outcome upon discharge and causes of death). Content validity of the instrument was determined through the use of panel ex

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Publication Date
Thu May 04 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Qualitative and Quantitative Study of the Zooplankton Community in Madinat Al-Alab Lake at Baghdad
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Zooplanktons from the artificial lake of Madenat Al-Alaab at Baghdad city have been
studied, during the period from may 2009 to April 2010. In addition to some ecological
factors (Temperature, pH and Turbidity) which were ranged (10.2-28.4)°C (7.1-8.4) and (20-50) cm respectively.
The results of the present study revealed that there are 22 species of zooplankton
belonging to Cladocera, Copepoda and Rotifera. Some of the species recorded during all
months of the study period, while other have disappeared during some months. Numbers of
species recorded were varied during different groups .
The dominant species were (Cyclops vernalis, C. hyalinus, C. scutifer, Diaptomus
leptopus, Bosmina longirostris, Kerate

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