Preferred Language
Articles
/
bsj-1020
Study of R -molar ratio effect on the transformation of tetraethylorthosilicat precursor to gels in sol-gel technique
...Show More Authors

The effect of using different R -molar ratio under variable reaction conditions (acidic as well as basic environment and reaction temperature) have been studied. The overall experiments are driven with open and closed systems. The study shows that there is an optimum value for a minimum gelling time at R equal 2. The gelling time for all studied open system found to be shorter than in closed system. In acidic environment and when R value increased from 2 to 10, the gelling time of closed systems has increased four times than open systems at T=30 ?C and fourteen times when temperature reaction increased to 60 ?C. While in basic environment the influence of increasing R value was limited.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Dec 28 2017
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Increasing Carbon Concentration Increasing on the Mechanical Properties of TiCx Thin Films
...Show More Authors

Carbides or nitrides thin films present materials with good mechanical properties for industrial applications as they can be coatings at low temperatures serve temperature sensitive surfaces. In this work the effect of the C percentage on the mechanical properties represented by the Young modulus (E) of combinatorial magnetron sputtered TiCx (34%x˂65%) has been studied. The structure of the produced films is TiC independent on the C concentration. The mechanical properties are increased with increasing the C concentration up to 50%, and then decreasing with further C % increasing. These results can be explained by considering the resultant residual stresses.

View Publication Preview PDF
Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
The effect of current density on the structures and photoluminescence of n-type porous silicon
...Show More Authors

Porous silicon (PS) layers were formed on n-type silicon (Si) wafers using Photo- electrochemical Etching technique (PEC) was used to produce porous silicon for n-type with orientation of (111). The effects of current density were investigated at: (10, 20, 30, 40, and50) mA/cm2 with etching time: 10min. X-ray diffraction studies showed distinct variations between the fresh silicon surface and the synthesized porous silicon. The maximum crystal size of Porous Silicon is (33.9nm) and minimum is (2.6nm) The Atomic force microscopy (AFM) analysis and Field Emission Scanning Electron Microscope (FESEM) were used to study the morphology of porous silicon layer. AFM results showed that root mean square (RMS) of roughness and the grain size of p

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Dec 15 2023
Journal Name
Journal Of Baghdad College Of Dentistry
The effect of different curing distances on the microhardness of flowable bulk-fill composite materials
...Show More Authors

Background: The microhardness of a composite resin is a vital parameter that is used to determine its clinical behavior. Measuring the microhardness of a composite resin has been used as an indirect method to assess its degree of conversion and extent of polymerization. The purpose of this in vitro study was to evaluate the effect of three curing distances (0, 2, and 4 mm) on the microhardness of the top and bottom surfaces of three types of flowable bulk-fill composite resins (smart dentin replacement, Opus bulk fill flow, and Tetric N). Material and method: Sixty-three specimens from the three types of composite resins (n=21) were fabricated using Teflon mold with a 4mm depth and a 5 mm internal diameter and cured for 20 seconds. For e

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Crossref
Publication Date
Mon Jun 22 2020
Journal Name
Baghdad Science Journal
Studying the Effect of Magnesium Oxide Nanoparticles Prepared on the Surface of Poly Methyl Methacrylate
...Show More Authors

          In this paper, magnesium oxide nanoparticles (MgO NPS) have been prepared and characterized and its concentration effect has been studied on polymers surface (MgO NPS). The results showed that the degradation of poly methyl methacrylate increased when using such metal oxide. The results also showed that the metal oxide increased the degradation of poly methyl methacrylate. X-ray diffraction, scanning electron microscopy, atomic force microscopy were used to study the morphological characteristics and size of nano MgO particles analysis.  Films were prepared by mixing the different masses of MgO NPS (0.025, 0.05, 0.1, 0.2 and 0.4) % with a polymer solution ratio (W/V) 7 %. Photo-

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Sat Dec 01 2018
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Walled Nano-Carbon on the Physical, Thermal and Mechanical Properties of Epoxy
...Show More Authors

The physical, the thermal and the mechanical properties of Nano-composites, that consisted of Polyprime EP epoxy that reinforced by multi-walled carbon nanotubes (MWCNTs), have been studied. Various loading ratios, 0.1, 0.5, and 1 wt. %of MWCNT shave been infused into epoxy by a magnetic stirrer and then the hardener mixed with the mthat supplied with the epoxy. All sample shave been cutting using CNC machine. Tensile test, three-point bending, hardness tests, lee's disk, differential scanning calorimetry, water absorption and dielectric and electrical conductivity test were utilized on unfilled, MWCNT-filled epoxy to identify the loading effect on the properties of materials. Scanning electron microscopy (SEM) was used to determine the

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Feb 20 2019
Journal Name
Iraqi Journal Of Physics
The effect of volume fraction on the fatigue strength of unsaturated polyester / glass fiber composite
...Show More Authors

 In this work polymeric composites were done from unsaturated polyester as a matrix reinforced with glass fiber type (E-glass) with two different volume fraction 20% & 40%. Fatigue tests showed that the number of fatigue cycles to failure limit for samples reinforced with uniform (woven Roving 0-90°) E-glass fiber and random (continuous fibers) with volume fraction 40% more than that for the same samples with volume fraction 20%. Also the fatigue results showed that the uniform samples failed with fatigue cycles more than that of random.

View Publication Preview PDF
Crossref
Publication Date
Thu Dec 14 2023
Journal Name
Malaysian Journal Of Mathematical Sciences
The Effect of Alternative Resource and Refuge on the Dynamical Behavior of Food Chain Model
...Show More Authors

This article examines and proposes a dietary chain model with a prey shelter and alternative food sources. It is anticipated that mid-predators' availability is positively correlated with the number of refuges. The solution's existence and exclusivity are examined. It is established that the solution is bounded. It is explored whether all potential equilibrium points exist and are locally stable. The Lyapunov approach is used to investigate the equilibrium points' worldwide stability. Utilizing a Sotomayor theorem application, local bifurcation is studied. Numerical simulation is used to better comprehend the dynamics of the model and define the control set of parameters.

View Publication
Scopus (10)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Reflection of mergers and acquisitions in the stock returns and financial performance - An Empirical Study of major international companies to the pharmaceutical industry-
...Show More Authors

Research aims to identify the immediate impact of the announcement of mergers in the stockholders and the feasibility of gain abnormal return and benefiting from  asymmetric information during the announcement that unite 30 days before the announcement of the merger, and announcement day, and 30 days after the announcement of the merger. It was the largest and most important mergers and acquisitions pick that occurred during the global financial crisis, specifically in health care/pharmaceutical industry, Pfizer and Wyeth merger with Novartis acquisition on Alcon. search has adopted three hypotheses: the first hypothesis that ((achieves the target company's shareholders positive abnormal return (or negative) during and befor

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Sep 15 2021
Journal Name
Geomechanics And Geoengineering
Effect of Deep Remediation and Improvement on Bearing Capacity and Settlement of Piled Raft Foundation Subjected to Static and Cyclic Vertical Loading
...Show More Authors

View Publication Preview PDF
Scopus (8)
Crossref (10)
Scopus Clarivate Crossref
Publication Date
Wed Nov 14 2018
Journal Name
Journal Of Engineering And Applied Sciences
DEMONSTRATE OF MAGNETIC FIELD EFFECT ON THE CAPABILITY OF ADSORPTION PROCESS IN THE REMOVAL OF AZO DYE FROM THE AQUEOUS SOLUTIONS ON CALCINED IRAQI BENTONITE CLAY MINERAL VIA COLUM
...Show More Authors