Preferred Language
Articles
/
joe-3013
INFLUENCE OF AMBIENT TEMPERATURE ON STIFFNESS OF ASPHALT PAVING MATERIALS
...Show More Authors

Asphalt pavement properties in Iraq are highly affected by elevated summer air temperatures. One of these properties is stiffness (resilient modulus). To explain the effect of air temperatures on stiffness of asphalt concrete, it is necessary to determine the distribution of temperatures through the pavement asphalt concrete layers. In this study, the distribution of pavement temperatures at three depths (2cm,7cm, 10cm) below the pavement surface is determined by using the temperature data logger instrument. A relationship for determining pavement temperature as related to depth and air temperature has been suggested. To achieve the objective of this thesis, the prepared specimens have been tested for indirect tension in accordance with ASTM D4123, using the pnuematic repeated load apparatus, in order to determine the values of resilient modulus at three different temperatures (10, 25, 40) °C. From results of testing, it is observed that the resilient modulus decreases with increase in test temperature by a rate of 8.78×10 Psi/C' for asphalt concrete wearing courses. An increase in optimum asphalt content by 0.1% (by weight of total mixture) causes a decrease in resilient modulus by 22% at a temperature of 40C". A statistical model for the prediction of resilient modulus has been developed depending on mixture variables of: asphalt content, asphalt hinder viscosity, surface area of combined aggregates, air voids of compacted mixture and test temperature.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Mar 28 2018
Journal Name
Iraqi Journal Of Science
Effect of Silver Nanoparticles on Fluorescence Spectra of C480 dye
...Show More Authors

This work aim to study the effect of silver nanoparticles on fluorescence intensity of Coumarin 480 dye by using the sandwiches technique where AgNP layer had been separated from C480 layer by different type of materials such as silica, PMMA polymer and PVA polymer layer. Silver nanoparticles had been prepared by the chemical reduction method so the AgNP layer coating had been done by hot rotation liquid method. The optical properties of prepared samples had been tested by using UV-VIS absorption spectrophotometer and Fluorescence spectrophotometer. Morphology, average size and the structure of nanoparticles were estimated using AFM, SEM testes

View Publication Preview PDF
Publication Date
Wed May 01 2019
Journal Name
Materials Science And Engineering
Effect of nanoparticles on thermal conductivity of epoxy resin system
...Show More Authors
Abstract<p>In this paper the effect of mixing TiO2 nanoparticles with epoxy resin is studied. The TiO2 nanoparticles would be synthesis and characterized by scanning electron microscopy (SEM), XRD FTIR, for two particle sizes of 50 and 25 nm. The thermal conductivity is measured with and without composite epoxy resin; the results showed that the thermal conductivity was increased as nanoparticle concentration increased too. The thermal conductivity was increased as particle size decreased.</p>
Preview PDF
Scopus (8)
Crossref (6)
Scopus Clarivate Crossref
Publication Date
Tue Feb 13 2024
Journal Name
Iraqi Journal Of Science
On q-SZASZ- Mirakyan Operators of functions of Two Variables
...Show More Authors

In this paper, we define two operators of summation and summation-integral of q-type in two dimensional spaces. Firstly, we study the convergence of these operators and then we prove Voronovskaya- type asymptotic formulas for these operators.

View Publication Preview PDF
Publication Date
Thu Apr 27 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Effect of Humidity on Superconducting Phase of Bi-2223
...Show More Authors

  The ceramics specimens as superconducting phase (Bi2PbxSr2Ca2Cu3O10+δ) with different concentrations of Pb from (0.0-0.5) were prepared by solid-state reaction method. Superconducting samples were exposed to high humidity (RH 75% at 25ºC) for seven weeks time interval. The humidity has a negative effect on the transition temperature of superconductor phase .It destroys the superconducting phase and the samples were converting to insulator.  
 

View Publication Preview PDF
Publication Date
Sun Mar 03 2013
Journal Name
Baghdad Science Journal
Effect of Magnetic Water Treatment on Prevention of CaCO3 Scales
...Show More Authors

Permanent magnets of different intensities were used to investigate the effect of a magnetic field in the process of preventing deposits of calcium carbonate. The magnets were fixed on the water line from the tap outside. Then heating a sample of this water in flasks and measuring the amount of sediment in a manner weighted differences. These experiments comprise to the change of the velocity of water flow, which amounted to (0.5, 0.75, 1) m/sec through the magnetic fields that are of magnetic strength (2200, 6000, 9250, 11000) Gauss, and conduct measurements, tests and compare them with those obtained from the use of ordinary water.The results showed the effectiveness of magnetic treatment in reducing the rate of deposition of calcium carb

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Engineering
The Effect of Shear on the Properties of Rigid PVC
...Show More Authors

The rheological and fusion behavior of polyvinyl chloride (PVC) compounds plays a dominant role in
the processing operations and in the development of physical properties in the processed material. A
comprehensive study was made in this work to evaluate the effect of shear and thermal history on stability, mechanical and rheological properties of rigid PVC compounds. Different samples of Rigid Poly vinyl chloride including dry blend powder, granules, and bottles molded from both were examined. A study was also made on recycled RPVC where 25% of reclaimed material was continuously blended with fresh dry blend and processed for 15 cycles. Results showed that compaction of the PVC material took place in the brabender plastograph at co

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sun May 01 2022
Journal Name
Journal Of Ovonic Research
Effect of antimony on characteristics of HgBa2CaCu2-xSbxO8+δ superconducting
...Show More Authors

In this work, HgBa2CaCu2-xSbxO8+δ compounds with (x = 0.2, 0.4, 0.6 and 0.8) have been prepared by the solid-state reaction method. Structural, morphological, and electrical properties were investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. Using the 4-probe technique to study the effect of antimony-substitution for Copper on the electrical properties of HgBa2CaCu2-xSbxO8+δ (Hg-1212) phase was investigated by measuring the resistivity as a function of temperature. Results indicate that the addition of antimony (Sb) increases the volume fraction of the phase and changes the superconducting transition temperature Tc of the superconductor to a normal state. The dielectric loss factor and ac

... Show More
View Publication
Scopus (4)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Wed Feb 29 2012
Journal Name
Al-khwarizmi Engineering Journal
Effect of Construction Joints on Performance of Reinforced Concrete Beams
...Show More Authors

Construction joints are stopping places in the process of placing concrete, and they are required because in many structures it is impractical to place concrete in one continuous operation. The amount of concrete that can be placed at one time is governed by the batching and mixing capacity and by the strength of the formwork. A good construction joint should provide adequate flexural and shear continuity through the interface.

In this study, the effect of location of construction joints on the performance of reinforced concrete structural elements is experimentally investigated.

Nineteen beam specimens with dimensions of 200×200×950 mm were tested. The variables investigated are the location of the construction joints

... Show More
View Publication Preview PDF
Publication Date
Thu Nov 02 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
A Study of Adsorption of Zr (IV) on Manganese Dioxide
...Show More Authors

The adsorption of zirconium, on manganese dioxide from nitric

acid solutions has been studied as a function of shaking time, concentration  of  electrolytes,  concentration  of  adsorbate  and temperature effects (25- 90°C).

Four   hours   of   shaking  was   appropriate  to   ensure   that  the

adsorption plateau was reached and the adsorption of zirconium decrease with an increase in nitric acid concentration. The limiting adsorption  capacities at 3 molar nitric acid was 0.2 Zr per mole of Mn02.   Working  at  elevated   temperature  was  in  favour  

... Show More
View Publication Preview PDF
Publication Date
Tue Feb 28 2017
Journal Name
Journal Of Engineering
Effects of Magnetized Water on the Accumulated Depth of Infiltration
...Show More Authors

This study was carried out to investigate the effects of magnetized water on accumulated infiltration depth. A test rig was designed and constructed for this purpose was installed at the water tests laboratory of the Department of Water Resources Engineering at the University of  aghdad. The investigation was carried out by using two types of soil, different flow velocities throughout magnetizing device and different configuration of magnets over and under the water passage of the magnetizing device. The soils that were used in the experiments are clayey and sandy soils.  Six different flow velocities throughout magnetizing device ranged between 0.29 to 1.19 cm/s and ten configurations of arranging the magnets over and under th

... Show More
View Publication Preview PDF