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Online column preconcentration for speciation and selective determination of Cr(III) in natural water samples using flow injection with chemiluminescence detection
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Abstract<p>A simple, rapid, sensitive and inexpensive approach is described in this work based on a combination of solid‐phase extraction of 8‐hydroxyquinoline (8HQ), for speciation and preconcentration of Cr(III) and Cr(VI) in river water, and the direct determination of these species using a flow injection system with chemiluminescence detection (FI–CL) and a 4‐diethylamino phenyl hydrazine (DEAPH)–hydrogen peroxide system. At different pH, the two forms of chromium [Cr(III) and Cr(VI)] have different exchange capacities for 8HQ, therefore two columns were constructed; the pH of column 1 was adjusted to pH 3 for retaining Cr(III) and column 2 was adjusted to pH 1 for retaining of Cr(VI). The sorbed Cr(III) and Cr(VI) species were eluted from columns using 3.0 ml of 0.1 N of HCl and 3.0 ml of 0.1 N of NaOH, respectively. The flow injection–chemiluminescence (FI–CL) method is based on light emitted due to the oxidation of DEAPH by the H<sub>2</sub>O<sub>2</sub> in the presence of Cr(III), which catalyzes the reaction. The flow cell is a transparent coiled tube made from glass (2.0 × 4.0, inner and outer diameter) and located close to the photodetector. The flow parameters: flow rate, sample volume, flow cell length, and distance to the CL detector were studied and optimized. Under optimum flow conditions, the Cr(III) concentration can be determined over the range 5–350 μg L<sup>−1</sup> with a limit of detection of 1.2 μg L<sup>−1</sup>, as the Cr(III) concentration is proportional to the intensity of the CL signal. The relative standard deviations (%) for 10 and 50 μg L<sup>−1</sup> Cr(III) were 1.2% and 3.2%, respectively. The effects of Al(III), Cd(II), Zn(II), Hg(II), Pb(II), Co(II), Cu(II), Ni(II), Mn(II), Ca(II), and Fe(III) were investigated. The proposed method is highly selective and sensitive, enabling a rapid determination of the Cr(III) amount in the presence of other interfering metals. Finally, the FI–CL method was examined in five river water samples with excellent recoveries.</p>
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Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Engineering
Effect Of Technology Based Learning As A Supplement To Traditional Technology On Student's Achievement
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This paper describes a practical study on the impact of learning's partners, Bluetooth Broadcasting system, interactive board, Real – time response system, notepad, free internet access, computer based examination, and interaction classroom, etc, had on undergraduate student performance, achievement and involving with lectures. The goal of this study is to test the hypothesis that the use of such learning techniques, tools, and strategies to improve student learning especially among the poorest performing students. Also, it gives some kind of practical comparison between the traditional way and interactive way of learning in terms of lectures time, number of tests, types of tests, student's scores, and student's involving with lectures

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Publication Date
Sat Jan 25 2025
Journal Name
Indonesian Journal Of Chemistry
Synthesis of CuO Nanoparticles from Copper(II) Schiff Base Complex: Evaluation via Thermal Decomposition
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Copper oxide (CuO) nanoparticles were synthesized through the thermal decomposition of a copper(II) Schiff-base complex. The complex was formed by reacting cupric acetate with a Schiff base in a 2:1 metal-to-ligand ratio. The Schiff base itself was synthesized via the condensation of benzidine and 2-hydroxybenzaldehyde in the presence of glacial acetic acid. This newly synthesized symmetric Schiff base served as the ligand for the Cu(II) metal ion complex. The ligand and its complex were characterized using several spectroscopic methods, including FTIR, UV-vis, 1H-NMR, 13C-NMR, CHNS, and AAS, along with TGA, molar conductivity and magnetic susceptibility measurements. The CuO nanoparticles were produced by thermally decomposing the

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Publication Date
Tue Jun 30 2020
Journal Name
Pakistan Journal Of Phytopathology
PROTECTIVE EFFECT OF OLIVE POLYPHENOLS ON WATERMELON AGAINST FUSARIUM OXYSPORUM F. SP. NIVEUM INFECTION
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Publication Date
Sun Dec 15 2019
Journal Name
Al-academy
Applications of Interior Space Design According to Shape Generation Systems: عبد الكريم علي حسين
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Treatises concerning analyzing the interior spaces multiplied and their directions varied, that some of them analyzed the interior space on the basis of the intellectual and philosophical affiliation or the historical period and others in the light of the concept and mechanisms of the shape. The researcher has not been able to find a research that dealt with analyzing the space within the systems of shape generation, thus it is possible to determine the research problem with the following question: to what extent is it possible to analyze the interior space based on systems of shape generation? As far as the importance of the research is concerned, it sheds light on five of the systems of the shape generation which are: Syntax, shape gra

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Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Engineering
Finite Element Analysis of Cracked One-Way Bubbled Slabs Strengthened By External Prestressed Strands
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Bubbled slabs can be exposed to damage or deterioration during its life. Therefore, the solution for strengthening must be provided. For the simulation of this case, the analysis of finite elements was carried out using ABAQUS 2017 software on six simply supported specimens, during which five are voided with 88 bubbles, and the other is solid. The slab specimens with symmetric boundary conditions were of dimensions 3200/570/150 mm. The solid slab and one bubbled slab are deemed references. Each of the other slabs was exposed to; (1) service charge, then unloaded (2) external prestressing and (3) loading to collapse under two line load. The external strengthening was applied using prestressed wire with four approaches, wh

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Publication Date
Fri Oct 01 2021
Journal Name
The Iraqi Postgraduate Medical Journal
Knowledge of Hypertensive Patients Attending Al-Imamein Kadhimein Medical City Regarding Follow-Up Visits
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Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
Characteristics of Zinc Oxide Film Prepared by Chemical Spray Deposition as a Gas Sensor
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Zinc oxide thin films were deposited by chemical spray pyrolysis onto glass substrates which are held at a temperature of 673 K. Some structural, electrical, optical and gas sensing properties of films were studied. The resistance of ZnO thin film exhibits a change of magnitude as the ambient gas is cycled from air to oxygen and nitrogen dioxide

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Publication Date
Wed Jun 02 2010
Journal Name
Journal Of Engineering
Bearing capacity of square footing on geogrid reinforced loose sand to resist eccentric load
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This research presents and discuss the results of experimental investigation carried out on geogrids model to study the behavior of geogrid in the loose sandy soil. The effect of location eccentricity, depth of first layer of reinforcement, vertical spacing, number and type of reinforcement layers have been investigated. The results indicated that the percentage of bearing improvement a bout (22 %) at number of reinforced layers N=1 and about (47.5%) at number of reinforced layers N=2 for different Eccentricity values when depth ratio and vertical spacing between layers are (0.5B and 0.75B) respectively

Publication Date
Wed Jan 31 2018
Journal Name
Engineering Journal
Residual Strength of Composite Unprotected Steel-Deck Floor Exposed to High Temperature (Fire Flame)
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Publication Date
Sun Mar 15 2020
Journal Name
Journal Of The College Of Education For Women
Rhetoric Effect of Ibn Al Faridh’s Poetry Counterparts: اسماء خليل ابراهيم, فرج منسي محمد
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 The Sufi poetry of Ibn Al-Faridh represents a true image of the spiritual  experience, in which he presented the bright aspects of  his experience, and his suffering in it, by formulating it in a poetic form, because the Sufi poetry is the result of an experience in which the Sufi seeks to achieve his goal of reaching the truth, and this is why Ibn Al-Faridh made his poetry a tool for expression on his own experience, the poet reflected his Sufi life in which he moved rhymes and weights.

   The poet Ibn Al-Faridh stands as a witness to his making of  Sufi poetry in the service of the purpose of who said, it is the embodiment of the Sufi journey in the stages, and the fluctuation in the places and si

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