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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 300 nm. It has been observed that; when the wavelength is increasing its absorption threshold is increased. For wavelengths (400, 500, 600) nm, the absorption thresholds for each quantum sizes are (1.8, 2.2. 3.2)nm respectively. On the other hand, a rising of the temperature led to reduces the absorption coefficient value, that at 400 K for all quantum sizes, the absorption coefficient increases >2000cm<sup>−1</sup>(According to the directed wavelength) than it is at 0 K. CdSe quantum dots can be considered as one of the most promising materials because it has a tuning gap for the visible wavelengthsfor different applications, such as light-emitting diodes in different colors of the visible spectrum. It is found that; there is a good agreement between our theoretical calculations and experimental results.</p>
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Publication Date
Sun Sep 01 2013
Journal Name
Baghdad Science Journal
Synthesis And Characterization Of Some New Acetylenic Mannich Bases Based On Biphenyl – 4,4 - Dithiol
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One of the most important , compound which have active hydrogen is the compound possessing (thiol group) Biphenyl-4,4-dithiol is agood example utilized in a wide field for preparation mannich bases , avariety of new acetylenic mannich bases have been Synthesized and all proposed structure were Supported by FTIR , 1H – NMR, 13C-NMR , Elemental analysis and microbial study .

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Publication Date
Sun Jun 30 2013
Journal Name
Al-khwarizmi Engineering Journal
Effect of Solid Particle Properties on Heat Transfer and Pressure Drop in Packed Duct
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This work examines numerically the effects of particle size, particle thermal conductivity and inlet velocity of forced convection heat transfer in uniformly heated packed duct. Four packing material (Aluminum, Alumina, Glass and Nylon) with range of thermal conductivity (from200 W/m.K for Aluminum to 0.23 W/m.K for Nylon), four particle diameters (1, 3, 5 and 7 cm), inlet velocity ( 0.07, 0.19 and 0.32 m/s) and constant heat flux ( 1000, 2000 and 3000 W/ m 2) were investigated. Results showed that heat transfer (average Nusselt number Nuav) increased with increasing packing conductivity; inlet velocity and heat flux, but decreased with increasing particle size.Also, Aluminum average Nusselt number is about (0.85,2.

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Publication Date
Sun Mar 02 2008
Journal Name
Baghdad Science Journal
Effect of Saline Water and Potassium Fertilizer on Nitrogen Fixation in Pisum sativum L.
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Field experiment was conducted to test the effect of saline water 2 and7 dSm-1 potassium fertilizer rate 150,300 and 450 kg/donum on nitrogen fixation in Pisum sativum L. nodules. The experiment included anatomy study .Results water salinity ( 2,7 dSm-1) as a main plot and fertilizer rates as a sub plot. Results indicated that irrigation with saline water 7 dSm-¹ caused a significant decrease in N contents especially in the lower parts of the plants. The percentage of the N decreased in lower leaves to (0.01%) under 7dSm-¹ and 300 kg/donum fertilizer; however the percentage increased in the upper leaves to (2.80%) under with 2dSm-¹of irrigation water and 300 kg/ donum fertilizer rate. Fresh weight decreased to 6.26g under 7 dSm

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Publication Date
Wed Jan 01 2020
Journal Name
Indian Journal Of Ecology
Study on major constraints and problems in transfer of technology by agricultural extension organization
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Publication Date
Mon May 28 2018
Journal Name
Iraqi Journal Of Science
Properties of fuzzy absolute value on R and Properties Finite Dimensional Fuzzy Normed Space
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The first aim in this paper is to introduce the definition of fuzzy absolute value on the vector space of all real numbers  then basic properties of this space are investigated. The second aim is to prove some properties that finite dimensional fuzzy normed space have.

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Publication Date
Mon Aug 26 2019
Journal Name
Iraqi Journal Of Science
Textural Analysis of Liver Tumor using Watershed Segmentation based on Statistical and Geometrical features
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The liver diseases can define as the tumor or disorder that can affect the liver and causes deformation in its shape. The early detection and diagnose of the tumor using CT medical images, helps the detector to specify the tumor perfectly. This search aims to detect and classify the liver tumor depending on the use of a computer (image processing and textural analysis) helps in getting an accurate diagnosis. The methods which are used in this search depend on creating a binary mask used to separate the liver from the origins of the other in the CT images. The threshold has been used as an early segmentation. A Process, the watershed process is used as a classification technique to isolate the tumor which is cancer and cyst.

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Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Adoption of ISSAI 5600 (Peer Review) by SAIs and its Impact on its Performance
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    تعد مراجعة النظير واحدة من الأســاليب الحديثة فــي مجال الرقابة والتدقيق ونشــأة كأداة لقياس مــدى فاعليــة الرقابــة علــى الجــودة هو لبنة أساسية في إدارة الجودة الشاملة ووسيلة لتحســين أدوات الرقابــة المعمول بها، وللتحقق من مدى الانسجام بين المعايير الدولية للأجهزة العليا للرقابة المالية والمحاسبة والاجراءات المعمول بها من قبل الاجهزة العليا للرقابة وعليه فأن مراجعة النظير أداة تستخدم ف

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Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
some Chemical effects on growth of azotobacter chroococcum wild-type and it's mutant-44
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the effecth of some chemicals on growth of two azotobacter chroococcum and aniline caused significant increase of growth

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Publication Date
Sun Mar 06 2016
Journal Name
Baghdad Science Journal
Biological and physiological effects of Coriandrum sativum on House fly Musca domestica (Diptera: Muscidae)
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This Study is conducted to evaluate effects of (leaves, fruits) powder and (oil, alcohol) extract of Coriander (Coriandrum sativum) plant on some biological and physiological aspects of House fly, Musca domestica at laboratory conditions. Result show that these preparations caused biological effects represented in high dead percentage in second instar, fed on different concentrations of food treated with them reached to 27.6, 55.3 at concentration 20% of leaf and fruit powder respectively and 67.3, 77.2% at 10% of oil and alcohol extract of fruit, respectively. Furthermore, study also show reduction in pupation and adults emergence percentage. However, leafs powder had slighter effect than powder and extract of fruit of tested plant. The st

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Publication Date
Wed Oct 01 2008
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Effect of aging on growth hormone-leptin axis in normal and obese healthy subjects
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Background: Growth hormone is a hormone responsible for the normal body growth and development by stimulation protein production in muscle cells and
energy release for breakdown of fat. On the other hand leptin is a newly discovered hormone that is mainly synthesized in adipose tissues it decreases food intake by
causing satiety and promoting energy combustion . Both aging and obesity are associated with a reduction in growth hormone secretion. In the mean time obese
humans have increased circulating leptin.
Objective: The aim of this paper is to shed light on the contribution of these two hormones in the mechanism of aging process in an attempt of improving this
process for a better life at old ages.&n

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