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Threshold Current Density of Al0.1Ga0.9N/GaN Triple Quantum Well Laser
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Semiconductor laser is used in processing many issues related to the scientific, military, medical, industrial and agricultural fields due to its unique properties such as coherence and high strength where GaN-based components are the most efficient in this field. Current technological developments mention to the strong connection of GaN with sustainable electronic and optoelectronic devices which have high-efficiency. The threshold current density of Al0.1Ga0.9N/GaN triple quantum well laser structure was investigated to determine best values of the parameters affecting the threshold current density that are well width, average thickness of active region, cavity length, reflectivity of cavity mirrors and optical confinement factor. The optimum value of the threshold current density is 2670 A/cm2 was obtained when the well width (w= 2.5 nm), reflectivity of cavity mirrors (R1=0.75, R2=0.9), cavity length (L=2mm), average thickness of active region (d= 11.5 nm), and optical confinement factor ( Γ= 0.034) at room temperature.

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Publication Date
Tue Feb 12 2019
Journal Name
Iraqi Journal Of Physics
The effect of deformation parameter of heavy nuclei on level density parameter
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The possible effect of the collective motion in heavy nuclei has been investigated in the framework of Nilson model. This effect has been searched realistically by calculating the level density, which plays a significant role in the description of the reaction cross sections in the statistical nuclear theory. The nuclear level density parameter for some deformed radioisotopes of (even- even) target nuclei (Dy, W and Os) is calculated, by taking into consideration the collective motion for excitation modes for the observed nuclear spectra near the neutron binding energy. The method employed in the present work assumes equidistant spacing of the collective coupled state bands of the considered isotopes. The present calculated results for f

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Publication Date
Thu Jan 01 2009
Journal Name
Iraqi Journal Of Science, Supplement 0f 2009
THE RELATIVE QUANTUM EFFICIENCY OF ANTHRACENE SOLUTION AS A FUNCTION OF LIGHT EXPOSURE DURATION
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Abstract In this paper the effect of light exposure duration on Anthracene solution in chloroform is studied. It is found that: the Anthracene solution change its color when it is exposed to light, and that its relative quantum efficiency, Φ, decreases as the light exposure duration, t, increases and this govern by following empirical equation:- Φ = 0.7918-0.0762 In (t)

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Publication Date
Fri Nov 01 2013
Journal Name
Isesco Journal Of Science And Technology
Effect of Solvents on the Dipole Moments and Fluorescence Quantum Yield of Rhodamine Dyes
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Abstract: This study aims to investigate the effects of solvents of various polarities on the electronic absorption and fluorescence spectra of RhB and Rh6G. The singlet‐state excited dipole moments (me) and ground state dipole moments (mg) were estimated from the equations of Bakshiev -Kawski and Chamma‐ Viallet using the variation of Stokes shift along with the solvent’s dielectric constant (e) and refractive indexes (n). The observed singlet‐state excited dipole moments were found to be larger than the ground‐state ones. Moreover, the obtained fluorescence quantum yield values were influenced by the environment of the fluorescing molecule. Consequently, the concentration of the dye solution, excited singlet state absorption and

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Publication Date
Sat May 01 2021
Journal Name
Journal Of Physics: Conference Series
The influence of temperature and size on the absorption coefficient of CdSe quantum dots
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Abstract<p>Because of Cadmium selenide quantum dots (CdSe quantum dots) has a tuning energy gap in the visible light range, therefore; it is provided a simple theoretical model for the absorption coefficient of CdSe quantum dots, where the absorption coefficient determines the extent to which the light of a material can penetrate a specific wavelength before it is absorbed. CdSe quantum dots have an energy gap can be controlled through two effects: the temperature and the dot size of them. It is found that; there is an absorption threshold for each directed wavelength, where CdSe quantum dots begin to absorb the visible spectrum at a size of 1.4 nm at room temperature for a directed wavelength 3</p> ... Show More
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Publication Date
Fri Jun 24 2022
Journal Name
Iraqi Journal Of Science
Determination the density of cometary nucleus material using gamma ray attenuation
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In this work, the technique of attenuation of gamma ray to calculate the density of comet nucleus materials (C/2009 P1 (GARRADD) at different range of energy (0.2- 0.9 MeV). also, the single scattering model for gamma rays has been assumed that photons reaching the detector with scattered only once in the material. The program has been designed and written in FORTRAN language (77 – 90) to calculate the density for molecules using Monte Carlo method was used to simulate the scattering and absorption of photons in semi- infinite material. Gamma ray interacts with the matter by three mainly interactions: Photoelectric effect, Compton scattering and Pair production (electron and positron). On the 137Cs source energy (662 keV), Compton scat

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Publication Date
Sun Jun 20 2021
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
CALCAREOUS NANNOFOSSILS BIOSTRATIGRAPHY OF JADDALA FORMATION IN WELL (AJEEL-10), CENTRAL IRAQ
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A detailed systematic study of calcareous nannofossils was carried out for the Jaddala Formation in (Aj-10) well, Central Iraq. Seventy one species belong to twenty four genera of calcareous nannofossils were identified including sixty two of them were previously named and nine species were identified for the first time and they would not be given names until more information is obtained in the future to support this identification.
It is a recorded of five biostratigraphic zone, which suggested the age of the Jaddala Formation to be of early to late Eocene. The recorded biozone includes the following: Reticulofenestra dictyoda (Deflandre in Deflandre & Fert, 1954) Stradner & Edwards, 1968 Partial Range Biozone (CNE 5); Discoa

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Publication Date
Thu May 04 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Effect of Electromagnetic Current in the Plantlet in vitro in Cucumis sativus L.
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Seeds of three American species of cucumber:-Lot number (EM285) signed as number 1,
To CAEEN F1 signed as number 2 ,and Hybird Super Green F1 signed as number 3, were
exposed to two kinds of physical effects .They were given :- 4 frequencies of the electric
current (0,1,2and 2.5) Am for five minutes using electro- magnetic generator .Then the three
species exposed to Ultra-Violet (UV)wave for four periods (0,30,60 and 90)sec. respectively
at 254 nm using Hood light .After exposure time the seeds were planted in sterlized
media(MS) with Benzyladenine (BA)and left in the incubator for2-3 weeks .Then ,plantlets of
the three species were taken to study the root system ,shoot system ,dry and wet weight for
them

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Publication Date
Tue Jul 01 2014
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
THE CURRENT STATUS OF THE VERTEBRATE DIVERSITY IN Al-DALMAJ MARSH, Al-DIWANIYA PROVINCE
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    A survey conducted at Dalmaj marsh, Al-Diwaniya Province during 2013 revealed that the marsh encounters a considerable part of the Iraqi vertebrate fauna including 147 species belonging to five classes; Pisces, Amphibia, Reptilia, Aves and Mammalia. Some species are of globally conservation importance. The present results are discussed with the pertinent literature.

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Publication Date
Fri Jan 20 2023
Journal Name
Bionatura
Impact of inflammatory markers, dread diseases and cycle threshold (Ct) Values in COVID-19 progression. Revis Bionatura 2023; 8 (1) 33
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Publication Date
Fri Sep 15 2017
Journal Name
Journal Of Baghdad College Of Dentistry
Impact of bitter taste threshold on caries experience in relation to ABO blood types among dental students at Al Kufa University
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Background: Blood group system and the ability to taste phenylthiocarbamide (PTC) are the most studied traits in human genetics which have been extensively used in describing genetic variations among human populations around the world that may had an effect on dental caries. The aims of present study were to investigate the caries experience among students with different bitter taste threshold in relation to blood type. Materials and Methods: The sample of present study includes dental students female aged19-21 years. The diagnosis of dental caries was done according to the criteria of Manjia et al, 1989 recording decayed lesion by severity (D1-4) MFS. Furthermore, bitter taste sensitivity was measured according to PTC (phenylthiocarbamid

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