Preferred Language
Articles
/
nRbuJIcBVTCNdQwCEjrg
ON THE REDUCTION OF PRESTRESSING FORCE NEAR SUPPORTS IN PARTIALLY PRESTRESSED CONCRETE FLEXURAL MEMBERS
...Show More Authors

Straight tendons in pretensioned members can cause high-tensile stresses in the concrete extreme fibers at end sections because of the absence of the bending stresses due to self-weight and superimposed loads and the dominance of the moment due to prestressing force alone. Accordingly, the concrete tensile stresses at the ends of a member prestressed with straight tendons may limit the service load capacity of the member. It is therefore important to establish limiting zone in the concrete section within which the prestressing force can be applied without causing tension in the extreme concrete fibers. Two practical methods are available to reduce the stresses at the end sections due to the prestressing force. The first method based on changing the eccentricity of some tendons by raising them towards the end zone. The second method is based on bond prevention by encasing some of the tendons in plastic sheathing, effectively moving the point of application of prestressing force inward toward midspan for part of tendons. The present study focuses on a proposed third method to reduce the effect of the prestressing force near end supports by using straight strands with limited initial prestressing value in compression zone. New equations were suggested for the cracking moment and the prestressing force which consider the prestressed tendons in compression zone.

Crossref
View Publication
Publication Date
Sat Sep 28 2019
Journal Name
Asian Journal Of Chemistry
Preparation, Spectroscopic Characterization and Theoretical Studies of Transition Metal Complexes with 1-[(2-(1H-indol-3-yl)ethylimino)methyl]naphthalene-2-ol Ligand
...Show More Authors

A new Schiff base [1-((2-(1H-indol-3-yl)ethylimino)methyl)naphthalene-2-ol] (HL) has been synthesized by condensing (2-hydroxy-1-naphthaldehyde) with (2-(1H-indol-3-yl)ethylamine). In turn, its transition metal complexes were prepared having the general formula; [Pt(IV)Cl2(L)2], [Re(V)Cl2(L)2]Cl and [Pd(L)2], 2K[M(II)Cl2(L)2] where M(II) = Co, Ni, Cu] are reported. Ligand as well as metal complexes are characterized by spectroscopic techniques such as FT-IR, UV-visible, 13C & 1H NMR, mass, elemental analysis. The results suggested that the ligand behaves like a bidentate ligand for all the synthesized complexes. On the other hand, theoretical studies of the ligand as well its metal complexes were conducted at gas phase using Hyp

... Show More
View Publication
Scopus (24)
Crossref (10)
Scopus Crossref
Publication Date
Sun Dec 01 2024
Journal Name
Baghdad Science Journal
Synthesis, Characterization and Antioxidant Study of Some Metal Ion Complexes with Azo 1-(2,4,6-trihydroxy-3-((3-hydroxyphenyl) diazenyl) phenyl) Ethan-1-one.
...Show More Authors

اثناء تفاعل الديزنة تكونت صبغة أزو جديدة عن طريق تفاعل 3-امينوفينول مع 2,4,6-ثلاثي هيدروكسي اسيتوفينون . ثم تم تفاعل هذا الليكاند مع بعض ايونات العناصر الكروم والحديد الروديوم والروثينيوم بتكفؤهم الثلاثي والكوبلت الثنائي والموليبدينوم سداسي التكافؤ مكونة معقدات فلزية مختلفة بأشكال هندسية متعددة. تم ملاحظة تناسق مجموعة الازو مع ايونات العناصر من خلال ملاحظة ظهور حزم امتصاص الفلز مع النتروجين والاوكسجين ب

... Show More
View Publication
Scopus (7)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Wed Jun 29 2022
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Kinetics and Energetic Parameters Study of Phenol Removal from Aqueous Solution by Electro-Fenton Advanced Oxidation Using Modified Electrodes with PbO2 and Graphene
...Show More Authors

The Electro-Fenton oxidation process is one of the essential advanced electrochemical oxidation processes used to treat Phenol and its derivatives in wastewater. The Electro-Fenton oxidation process was carried out at an ambient temperature at different current density (2, 4, 6, 8 mA/cm2) for up to 6 h. Sodium Sulfate at a concentration of 0.05M was used as a supporting electrolyte, and 0.4 mM of Ferrous ion concentration (Fe2+) was used as a catalyst. The electrolyte cell consists of graphite modified by an electrodepositing layer of PbO2 on its surface as anode and carbon fiber modified with Graphene as a cathode. The results indicated that Phenol concentration decreases with an increase in current dens

... Show More
View Publication Preview PDF
Crossref (13)
Crossref
Publication Date
Tue Sep 11 2018
Journal Name
Iraqi Journal Of Physics
Synthesis and characterization of ligands derived 2-hydroxy-1- naphthaldehyde and their complexes with divalent metal ions (Mn+2, Fe+2, Ni +2)
...Show More Authors

In this work, Schiff base ligands L1: N, N-bis (2-hydroxy-1-naphthaldehyde) hydrazine, L2: N, N-bis (salicylidene) hydrazine, and L3:N –salicylidene- hydrazine were synthesized by condensation reaction. The prepared ligands were reacted with specific divalent metal ions such as (Mn2+, Fe2+, Ni2+) to prepare their complexes. The ligands and complexes were characterized by C.H.N, FT-IR, UV-Vis, solubility, melting point and magnetic susceptibility measurements. The results show that the ligands of complexes (Mn2+, Fe2+) have octahedral geometry while the ligands of complexes (Ni2+) have tetrahedral geometry.

View Publication Preview PDF
Crossref
Publication Date
Thu Jan 01 2015
Journal Name
Diyala Journal For Pure Science
Synthesis and Spectroscopic Study of New Bidentate Schiff Base type (NN) and it’s Complexes with MnII, FeII, CoII, NiII, CuII and CdII Ions .
...Show More Authors

four coordinated complexes for divalent metal ions : Mn, Fe, Co, Ni, Cu and Cd have been synthesized using bidentate Schiff base ligand type (NN)formed by the condensation of o-phenylenediamine , p- methylbenzadehyde and furfural in methanol. The ligand was reacted with divalent metal chloride forming complexes of the types :[M(L)Cl2] where : MII=Mn, Fe, Ni, Cu, and Cd . These new compounds were characterized by elemental analysis, spectroscopic methods (FT-IR, U.V-Vis, 1HNMR (for ligand only and atomic absorption) , magnetic susceptibility, chloride content along with conductivity measurement. These studies revealed that the geometry for all complexes about central metal ion is tetrahedral.

Publication Date
Fri Jan 01 2016
Journal Name
Journal Of Engineering
A Mathematical Model of a Thermally Activated Roof (TAR) Cooling System Using a Simplified RC-Thermal Model with Time Dependent Supply Water Temperature
...Show More Authors

This paper presents a computer simulation model of a thermally activated roof (TAR) to cool a room using cool water from a wet cooling tower. Modeling was achieved using a simplified 1-D resistance-capacitance thermal network (RC model) for an infinite slab. Heat transfer from the cooling pipe network was treated as 2-D heat flow. Only a limited number of nodes were required to obtain reliable results. The use of 6th order RC-thermal model produced a set of ordinary differential equations that were solved using MATLAB - R2012a. The computer program was written to cover all possible initial conditions, material properties, TAR system geometry and hourly solar radiation. The cool water supply was considered time

... Show More
View Publication Preview PDF
Publication Date
Wed Jul 08 2009
Journal Name
Ibn Al-haitham Journal For Pure And Applied Science
Complexeation Behavior of CoII, NiII, CuII, ZnII, and CdII Ions Toward Schiff Base Derived From 2, 4 -Dihydroxy Benzaldehyde and O-Phenylene Diamine
...Show More Authors

bstract The aim of this work covers the synthesis and characterization of the new tertra dentate ligand (H4L) containing (N and O) as donor set atoms kind (N2O2) where: H4L=Bis-1,2 (2,4- dihydroxybenzylediene phylinediamine . The preparation of ligand contains reaction 2, 4 - Dihydroxy benzaldehyde and o-phenylene diamine . Schiff base was reacted with some metal ions in the presence of methanol to give the complexes in the general formula [M (H2L)] where: MII = Co, Ni, Cu, Zn, Cd. All compounds were characterized by spectroscopic methods I.R , U.V.-Vis, metal content and molar conductivity measurements, showed that the complexes are non-electrolyte. The proposed geometry for all of the proposed complexes was a tetrahedral while Ni complex

... Show More
Publication Date
Mon May 01 2017
Journal Name
Al-mustansiriyah Journal Of Science
Synthesis, characterization and antibacterial Evaluation for mixed-ligand Complexes of Nickle (II), Manganese (II), Copper (II), Cobalt (II) and Mercury (II) with Tetradentate
...Show More Authors

Publication Date
Thu Mar 03 2022
Journal Name
V. International Scientific Congress Of Pure, Applied And Technological Science (minar Congress)
synthesis and characterization of new Co(II), Zn(II) and Cd(II) complexes derived from oxadiazole ligand and 1,10-phenanthroline as co-ligand
...Show More Authors

In this work, prepared new ligand namely 5-(2,4-dichloro-phenyl)-1,3,4-oxadiazole-2-(3H)-thion, was obtained from the 2,4-dichlorobenzoyl chloride with hydrazine, after that reaxtion with CS2/KOH in methanol.

Publication Date
Sat Jan 01 2022
Journal Name
Pharmacia
Synthesis, docking study, and structureactivity relationship of novel niflumic acid derivatives acting as anticancer agents by inhibiting VEGFR or EGFR tyrosine kinase activities
...Show More Authors

Scopus (21)
Scopus