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joe-2070
Evaluation of Convective Heat Transfer and Natural Circulation in an Evacuated Tube Solar Collector
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The evacuated tube solar collector ETC is studied intensively and extensively by experimental and
theoretical works, in order to investigate its performance and enhancement of heat transfer, for Baghdad climate
from April 2011 till the end of March 2012. Experimental work is carried out on a well instrumented collector
consists of 16 evacuated tubes of aspect ratio 38.6 and thermally insulated tank of volume 112L. The relation
between convective heat transfer and natural circulation inside the tube is estimated, collector efficiency, effect of
tube tilt angles, incidence angle modifier, The solar heating system is investigated under different loads pattern (i.e
closed and open flow) to evaluate the heat loss coefficient from tank and tubes, test the collector with various
aspect ratios (32.9 and 27.2). The enhancement in collector performance is studied by using two reflectors (Flat
Plate and Curved Plate) and nanofluid (Water-AL2O3).Theoretical work is run by software (Fluent 6.3), to compute
the velocity and temperature profiles within the tube, for different tube diameters, effect of tube junction angle and
stagnant region in the bottom of the evacuated tube. The experimental results shows that the heat loss coefficient
for tube is W/m2.K and for tank is W/m2.K, the maximum collector temperature is 79°C in winter and
99°C in summer, while that belong to nanofluid collector is 99°C in winter. The best tilted angle (optimum) of
evacuated tube is 41° annually. The collector efficiency increased when using nanofluid of (1, 0.6, 0.3)% volume
fraction as(28.4, 6.8, 0.6)% respectively. The efficiency decreases as (33, 62)% when decreasing tube aspect ratio
from 38.6% to 32.9% and 27.2% respectively. An increase of (16.9 and 7.08)% in collector efficiency is obtained
when using curved and flat plate reflectors respectively. From simulation the best junction angle of the tank is
22.5°. The stagnant region is influenced with changing heat flux, tilted angle and aspect ratio.

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Publication Date
Thu Dec 29 2016
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
A new Spectrophotometric Method For The Determination of La (III) With 3-Hydroxy -4-(2-hydroxyPhenyl azo) Naphthalene -1- Sulfonic Acid
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A simple, rapid and sensitive spectrophotometric method has been proposed for the determination of La (III) using 3-hydroxy -4-(2-hydroxy-phenyl azo) naphthalene -1- sulfonic acid as a chromogenic reagent. This method is based on the formation of a red-pink colored complex, upon the reaction of La(III) with the reagent in an alkaline medium (pH= 9.50), having a maximum absorbance at 459 nm. Beer's law is valid in the concentration range 0.512 µg.ml-1 with a Sandell's sensitivity value of 0.0188 µg.cm-2 and molar absorptivity of 7376.12 L.mol-1.cm-1. The stoichiometric composition of the chelate is 1:3. The effect of the presence of different cations as interferants in the determination of La(III) under the given optimum conditions

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Publication Date
Fri Nov 24 2023
Journal Name
Iraqi Journal Of Science
Laboratory Studies on the Effects of the Entomopathogenic fungus Beauveria bassiana (Bals.) Vuill, on the Homaira insect, Batrachedra amydraula (Lepidoptera : Cosmopterygidae)
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This study was conducted to evaluate the pathogenicity of Beauveria bassiana to the Homaira insect Batrachedra. amydraula under laboratory conditions. The dilution 1 x 10-2 showed a significant and high mortality rates on the eggs, first and fifth instars of the homaira larvae which reaches 100%, 96.19% and 91.20% after 7 days from treatment. However mortality rates found to be decreased to 88.97% for fifth instar after 10 days from treatment, while results showed parasitism potentially reaches 94.50% in pupae and 90.22% in adults.

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Publication Date
Wed Jan 01 2014
Journal Name
Journal Of The College Of Languages (jcl)
La réception du Petit Prince de Saint-Exupéry dans le monde arabe The impact of The Little Prince on Arabic audience
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Le Petit Prince est apparu en 1943 vers la fin de la vie de son auteur. La mondialité qu'a gagnée ce récit le rend un des livres les plus lus et les plus vendus dans le monde. Cette popularité en fait un des classiques de la littérature française.

En effet la littérature française a un impact profond et direct sur la vie intellectuelle et littéraire dans le monde arabe. La circulation des œuvres littéraires écrites en français a bien influencé les lecteurs arabes soit en langue française  soit  traduites en arabe. Cette réalité est identique lorsqu'on parle de la réception du Petit Prince ; l'œuvre la plus connue dans le monde entier dès son apparition officielle.

Ab

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Publication Date
Fri Sep 29 2023
Journal Name
International Journal Of Nanoscience
Preparation of N-A Cysteine-capped CdTe/CdS/ZnS core/shell/shell QDs as a Selective Probe for Detecting Damaged DNA
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In this study, NAC-capped CdTe/CdS/ZnS core/double shell QDs were synthesized in an aqueous medium to investigate their utility in distinguishing normal DNA from mutated DNA extracted from biological samples. Following the interaction between the synthesized QDs with DNA extracted from leukemia cases (represents damaged DNA) and that of healthy donors (represents undamaged DNA), differential fluorescent emission maxima and intensities were observed. It was found that damaged DNA from leukemic cells DNA-QDs conjugates at 585 nm while intact DNA (from healthy subjects) DNA–QDs conjugates at 574 nm. The obtained results from the optical analyses indicate that the prepared QDs could be utilized as probe for detecting disrupted DNA th

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Publication Date
Thu Dec 14 2023
Journal Name
Optical And Quantum Electronics
Enhancing response characteristics of palladium-doped vanadium pentoxide on a porous silicon substrate as gas sensor synthesized by pulsed laser deposition
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Publication Date
Mon Apr 24 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Improved 𝑫−𝑯𝒆 𝟑 Fusion Reaction Characteristics Parameters
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   The most likely fusion reaction to be practical is Deuterium and Helium-3 (𝐷−𝐻𝑒
 3 ), which is highly desirable because both Helium -3 and Deuterium are stable and the reaction produces a 14 𝑀𝑒𝑉 proton instead of a neutron and the proton can be shielded by magnetic fields. The strongly dependency of the basically hot plasma parameters such as reactivity, reaction rate, and energy for the emitted protons, upon the total cross section, make the problems for choosing the desirable formula for the cross section, the main goal for our present work.

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Publication Date
Sun Oct 06 1996
Journal Name
Iraqi Journal Of Chemistry
Synthesis of new Schiff bases derived from [3-amino-3-C-cyano-3-deoxy-1,2:5,6-di-O-isopropylidene-α-D-allofuranose
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Aromatic Schiff-bases are known to have antibacterial activity, but most of these compounds are sparingly soluble in water. The present work describes the synthesis of new Schiff-bases derived from branched aminosugars. Treatment of 3-Amino-3-Cyano-3-Deoxy-1,2:5,6-Di-O-Isopropylene-α-D-Allofuranose (1) with the aldehydes (2) under reflux in methanol afforded the Schiff-bases (3) in good yields. The new Schiff-bases were in accord with their NMR, IR spectral data and elemental analysis.

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Publication Date
Fri Oct 28 2022
Journal Name
Political Sciences Journal
A future view for the political systems of the Arab Gulf states After normalization ... the United Arab Emirates as a case study
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The dangers of (Israel's) integration with Arab countries in the middle east region will threaten the Arab security structure dimension, which the latter makes the Arab regional system vulnerable for distortion due to its nominal and symbolic value which is far from the Arab self and questioning with its effectiveness in comparing with the real capabilities to Arab countries in achieving the common targets. So, how to assess the different problems that began to hit the structure of the Arab regional system? and how to pledge an allegiance after putting forward what is known as the American Deal of the Century for the administration of former US President Donald Trump for making another step toward normalization with (Israel)?. The reveal

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Publication Date
Thu Nov 04 2021
Journal Name
Optik - International Journal For Light And Electron Optics
Plasma parameters of Au nano-particles ablated on porous silicon produced via Nd-YAG laser at 355 nm for sensing NH3 gas
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The current study aimed the syntheses and characterizations of Gold nanoparticles (Au NPs) using a laser ablation Q-switched Nd: YAG laser with a wave-length of 355 nm at a variety of laser pulse energies (E) and deposited on porous silicon (PS). Optical emission spectrometer was used to diagnosed medium air to study gold plasma characteristics and prepared Au nanoparticles. The laser pulse energy influence has been studied on the plasma characteristics in air. The data showed the emergence of the ionic (Au II) spectral emission lines in the gold plasma emission spectrum. XRD has been utilized to examine structural characteristics. Moreover, AFM results 37.2 nm as the mean value of the diameter that is coordinated in a shape similar to the

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Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
The synergistic effect of Zeolites type (?) with chlorinated rubber as flame retardants for unsaturated polyester resin: Jalil R. Ugal| Zahraa Q. Mahdi
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In this work, the synergistic effect of chlorinated rubber (additive I),with zeolite 3A (additive II), zeolite 4A (additive III), and zeolite 5A (additive IV) in (1:1) weight percentage, on the flammability for unsaturated polyester resin was studied in the weight ratios for (3,7,10,13&15%) by preparing films of (130×130×3) mm in diameters. Three standard test methods used to measure were the flame retardation which are; ASTM: D-2863, ASTM: D- 635& ASTM: D-3014. Results obtained from these tests indicated that all of the additives were effective additive IV has the highest efficiency as a flame retardant.

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