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FREE VIBRATION ANALYSIS OF NOTCHED COMPOSITE LAMINATED CANTILEVER BEAMS
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The present work divided into two parts, first the experimental side which included the
measuring of the first natural frequency for the notched and unnotched cantilever composite beams
which consisted of four symmetrical layers and made of Kevlar- epoxy reinforced. A numerical
study covers the effect of notches on the natural frequencies of the same specimen used in the
experimental part. The mathematical model for the beam contains two open edges on the upper
surface. The effect of the location of cracks relative to the restricted end, depth of cracks, volume
fraction of fibers and orientation of the fiber on the natural frequencies are explored. The results
were calculated using the known engineering program (ANSYS), the results obtained has been
compared with those calculated analytically by (Sierakowski RL.), which have expressed the closest
well also the comparison between the experimental results with that calculated by (ANSYS) has
very well. The study shows that the highest difference in frequencies occur when the value of the
fiber orientation equal to 0odegree, the effect of location of the cracks decrease when the cracks
moving toward the free end and also shows that an increase of the depth of the cracks leads to a
decrease in the values of natural frequencies.

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Publication Date
Thu Aug 31 2017
Journal Name
Journal Of Engineering
Energy Analysis of Solar Collector With perforated Absorber Plate
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The thermal performance of three solar collectors with 3, 6 mm and without perforation absorber plate was assessed experimentally. The experimental tests were implemented in Baghdad during the January and February 2017. Five values of airflow rates range between 0.01 – 0.1 m3/s were used through the test with a constant airflow rate during the test day. The variation of the following parameters air temperature difference, useful energy, absorber plate temperature, and collector efficiency was recorded every 15 minutes. The experimental data reports that the increases  the number of absorber plate perforations with a small diameter is more efficient rather than increasing the hole diameter of the absorber plate with decr

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Publication Date
Tue Dec 01 2009
Journal Name
Iraqi Journal Of Physics
Spectrophotometrically Analysis of PMMA as a low – Doses Dosimeter
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Polymethylmethacrylate film (PMMA) of thickness 75 μm was evaluated Spectrophotometrically for using it as a low-doses gamma radiation dosimeter. The doses were examined in the range 0.1 mrad-10 krad. Within an absorption band of 200-400 nm, the irradiated films showed an increase in the absorption intensity with increasing the absorbed doses. Calibration curves for the changes in the absorption differences were obtained at 218, 301, and 343 nm. At 218 nm the response for the absorbed doses is a linear in the range 10 mrad- 10 krad. Hence it is recommended to be adopted as an environmental low doses dosimeter

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Publication Date
Tue Jun 01 2021
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Genomics and Molecular Phylogenetics Tree Analysis of Actinopolyspora Iraqiensis
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Actinopolyspora iraqiensis IQ-H1 is a novel strain of actinobacteria isolated from extremely halophilic soil samples in Iraq. The whole-genome sequence of this strain is deposited in the National Center for Biotechnology Information (NCBI) GenBank under the accession number NZ_AICW01000000. In this study, the genome features and the molecular phylogenetic tree of Act. iraqiensis IQ-H1are analyzed. The RAST tool was used for genome annotation. The genomic features were elucidated using QUAST tool. The circular genome map, and the core and pan-genome map of Act. iraqiensis IQ-H1 was generated using CGView and the GView tools respectively. The JSpeciesWS server was used for the tetranucleotide signature analysis a

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Publication Date
Mon Apr 01 2013
Journal Name
International Journal Of Electrical, Electronics And Telecommunication Engineering
Performance Analysis of xPON Network for Different Queuing Models
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Passive optical network (PON) is a point to multipoint, bidirectional, high rate optical network for data communication. Different standards of PONs are being implemented, first of all PON was ATM PON (APON) which evolved in Broadband PON (BPON). The two major types are Ethernet PON (EPON) and Gigabit passive optical network (GPON). PON with these different standards is called xPON. To have an efficient performance for the last two standards of PON, some important issues will considered. In our work we will integrate a network with different queuing models such M/M/1 and M/M/m model. After analyzing IPACT as a DBA scheme for this integrated network, we modulate cycle time, traffic load, throughput, utilization and overall delay

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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Clouds Height Classification Using Texture Analysis of Meteosat Images
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In the present work, pattern recognition is carried out by the contrast and relative variance of clouds. The K-mean clustering process is then applied to classify the cloud type; also, texture analysis being adopted to extract the textural features and using them in cloud classification process. The test image used in the classification process is the Meteosat-7 image for the D3 region.The K-mean method is adopted as an unsupervised classification. This method depends on the initial chosen seeds of cluster. Since, the initial seeds are chosen randomly, the user supply a set of means, or cluster centers in the n-dimensional space.The K-mean cluster has been applied on two bands (IR2 band) and (water vapour band).The textural analysis is used

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Publication Date
Sat Sep 01 2018
Journal Name
Al-nahrain Journal For Engineering Sciences
Performance Analysis of FSO under Turbulent Channel Using OSTBC
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Free Space Optics (FSO) plays a vital role in modern wireless communications due to its advantages over fiber optics and RF techniques where a transmission of huge bandwidth and access to remote places become possible. The specific aim of this research is to analyze the Bit-Error Rate (BER) for FSO communication system when the signal is sent the over medium of turbulence channel, where the fading channel is described by the Gamma-Gamma model. The signal quality is improved by using Optical Space-Time Block- Code (OSTBC) and then the BER will be reduced. Optical 2×2 Alamouti scheme required 14 dB bit energy to noise ratio (Eb/N0) at 10-5 bit error rate (BER) which gives 3.5 dB gain as compared to no diversity scheme. Th

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Publication Date
Wed Sep 01 2010
Journal Name
Journal Of Engineering
Analysis of Concrete Flexural Members Reinforced with Fibre Polymer
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Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
Phylogenetic Analysis of Streptomyces spp. Exhibited Different Antimicrobial Activities
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Fourteen isolates were collected from a previous study and all were assigned to be Streptomyces genus, according to physiological and biochemical tests, however all the isolates varied morphologically and exhibited different antimicrobial activity.  All 14 isolates were confirmed Streptomyces by  16S rRNA PCR amplification. Six isolates with high antimicrobial activities were ascertained   Streptomyces spp. by sequencing and phylogenetic analysis. Two isolates among the selected 6 isolates with antimicrobial activity against  E. coli and S. aureus . It recommended to make a complete sequence for 16S  rRNA to detect the  species that

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Publication Date
Thu Jan 01 2009
Journal Name
Bayt Alhekma
COMPARATIVE ANALYSIS OF RUSSIAN AND ARABIC PHRASEOLOGICAL UNITS (TURNS)
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Abstract The study aimed at reviewing translation theories proposed to address problems in translation studies. To the end, translation theories and their applications were reviewed in different studies with a focus on issues such as critical discourse analysis, cultural specific items and collocation translation.

Publication Date
Fri Jul 01 2022
Journal Name
Iraqi Journal Of Science
Statistical Analysis of Extreme Rainfall Data in Baghdad City
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Studying extreme precipitation is very important in Iraq. In particular, the last decade witnessed an increasing trend in extreme precipitation as the climate change. Some of which caused a disastrous consequences on social and economic environment in many parts of the country. In this paper a statistical analysis of rainfall data is performed. Annual maximum rainfall data obtained from monthly records for a period of 127 years (1887-2013 inclusive) at Baghdad metrology station have been analyzed. The three distributions chosen to fit the data were Gumbel, Fréchet and the generalized Extreme Value (GEV) distribution. Using the maximum likelihood method, results showed that the GEV distribution was the best followed by Fréchet distribut

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