Preferred Language
Articles
/
joe-15
Enhancing Performance of Self–Compacting Concrete with Internal Curing Using Thermostone Chips
...Show More Authors

This paper is devoted to investigate the effect of internal curing technique on the properties of self-compacting concrete (SCC). In this study, SCC is produced by using silica fume (SF) as partial replacement by weight of cement with percentage of (5%), sand is partially replaced by volume with saturated fine lightweight aggregate (LWA) which is thermostone chips as internal curing material in three percentages of (5%, 10% and 15%) for SCC, two external curing conditions water and air. The experimental work was divided into three parts: in the first part, the workability tests of fresh SCC were conducted. The second part included conducting compressive strength test and modulus of rupture test at ages of (7, 28 and 90). The third part included the shrinkage test, at ages (7, 14, 21, 28) days. The results show that internally cured SCC has the best workability, and the best  properties of hardened concrete which include (compressive strength and modulus of rupture) then the externally cured SCC with both water and air as compared with reference concretes. Also, the hardened properties of internally cured SCC with replacement percentage of (10%) by thermostone chips is the best as compared with that of percentages (5% and 15%) for both external curing conditions. In general, the results of hrinkage test, showed reduction in shrinkage of internally cured SCC as compared with reference concrete.
 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Apr 01 2019
Journal Name
The Saudi Dental Journal
Implementation and characterization of coating pure titanium dental implant with sintered β-TCP by using Nd:YAG laser
...Show More Authors

Objectives This work presents laser coating of grade 1 pure titanium (Ti) dental implant surface with sintered biological apatite beta-tricalcium phosphate (β-TCP), which has a chemical composition close to bone. Materials and methods Pulsed Nd:YAG laser of single pulse capability up to 70 J/10 ms and pulse peak power of 8 kW was used to implement the task. Laser pulse peak power, pulse duration, repetition rate and scanning speed were modulated to achieve the most homogenous, cohesive and highly adherent coat layer. Scanning electron microscopy (SEM), energy dispersive X-ray microscopy (EDX), optical microscopy and nanoindentation analyses were conducted to characterise and evaluate the microstructure, phases, modulus of elasticity

... Show More
View Publication
Scopus (26)
Crossref (20)
Scopus Clarivate Crossref
Publication Date
Thu Jun 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
Using a hybrid SARIMA-NARNN Model to Forecast the Numbers of Infected with (COVID-19) in Iraq
...Show More Authors

Coronavirus disease (COVID-19) is an acute disease that affects the respiratory system which initially appeared in Wuhan, China. In Feb 2019 the sickness began to spread swiftly throughout the entire planet, causing significant health, social, and economic problems. Time series is an important statistical method used to study and analyze a particular phenomenon, identify its pattern and factors, and use it to predict future values. The main focus of the research is to shed light on the study of SARIMA, NARNN, and hybrid models, expecting that the series comprises both linear and non-linear compounds, and that the ARIMA model can deal with the linear component and the NARNN model can deal with the non-linear component. The models

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Nov 28 2018
Journal Name
Al-khwarizmi Engineering Journal
Effect of Using Combined Square Nozzle & winglet with Helical Tape on Thermal Characteristics in Tube Heat Exchanger
...Show More Authors

Influence of combined square nozzle with helical tape inserted in a constant heat flux tube on heat transfer enhancement for turbulent airflow for Reynolds number ranging from 7000 to 14500 were investigated experimentally. Three different pitch ratios for square nozzle (PR = 5.8, 7.7 and 11.6) according to three different numbers of square nozzle (N = 3, 4 and 5) and constant pitch ratios for helical tape were used. The results observed that the Nusselt number and friction factor for combination with winglets were found to be up to 33.8 % and 21.4 %, respectively higher than nozzle alone for pitch ratio PR=5.8. The maximum value of thermal performance for using combination with winglets was about 1.351 for pitch ratio= 5.8. Nusselt numb

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Nov 28 2016
Journal Name
Separation Science And Technology
Using sewage sludge as a permeable reactive barrier for remediation of groundwater contaminated with lead and phenol
...Show More Authors

Scopus (24)
Crossref (24)
Scopus Clarivate Crossref
Publication Date
Thu Sep 13 2018
Journal Name
Baghdad Science Journal
Study of the Electric Quadrupole Moments for some Scandium Isotopes Using Shell Model Calculations with Different Interactions
...Show More Authors

The electric quadrupole moments for some scandium isotopes (41, 43, 44, 45, 46, 47Sc) have been calculated using the shell model in the proton-neutron formalism. Excitations out of major shell model space were taken into account through a microscopic theory which is called core polarization effectives. The set of effective charges adopted in the theoretical calculations emerging about the core polarization effect. NushellX@MSU code was used to calculate one body density matrix (OBDM). The simple harmonic oscillator potential has been used to generate the single particle matrix elements. Our theoretical calculations for the quadrupole moments used the two types of effective interactions to obtain the best interaction compared with the exp

... Show More
View Publication Preview PDF
Scopus (6)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Sat Feb 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
Quality of internal audit and its impact on nature, timing and procedures of external audit An investigative study of a sample of external auditors Iraqi Solidary Companies for Auditing.
...Show More Authors

           The study aims at investigating the quality of internal auditing and its impact on nature, timing, and procedures of external audit, based on international auditing standards, in particular ISA (610). The standard ISA (610) requires the external auditors to assess independence, the scope of internal audit unit, competence, and due professional care of internal auditors as indicators that reflect the quality of internal audit performance before deciding to rely on internal auditors.

The sample of this study consisted of external auditors in Iraqi Solidary Companies for Auditing. A questionnaire was distributed to them via e-mail

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Jun 01 2011
Journal Name
Journal Of Economics And Administrative Sciences
Selection of the initial value of the time series generating the first-order self-regression model in simulation modeAnd their impact on the accuracy of the model
...Show More Authors

In this paper, compared eight methods for generating the initial value and the impact of these methods to estimate the parameter of a autoregressive model, as was the use of three of the most popular methods to estimate the model and the most commonly used by researchers MLL method, Barg method  and the least squares method and that using the method of simulation model  first order autoregressive through the design of a number of simulation experiments and the different sizes of the samples.

                  

View Publication Preview PDF
Crossref
Publication Date
Fri Oct 02 2020
Journal Name
International Journal Of Pharmaceutical Research
Effectiveness of Self-Instructional Strategy and the Traditional Teaching Approach on Nursing Students' Knowledge toward Cardiopulmonary Resuscitation at the College of Nursing in University of Baghdad: Randomized Comparative Trial
...Show More Authors

Background: Cardiopulmonary resuscitation (CPR) is a technique or procedure that combined chest compression and rescue breathing to maintain enough circulation that prevents brain damage until other essential steps are taken to control the main cause of cardiac and respiratory arrest. The health care personnel should be qualified in the performing of cardiopulmonary resuscitation (CPR) to improve the survival rate of the victims. Therefore; it is necessary to use new methods for learning [1]. Objectives: the study aims to compare the effectiveness of self-instructional teaching strategy and traditional teaching approach on student’s knowledge toward cardiopulmonary resuscitation. Methods: A randomized comparative trial (RCT) design was ca

... Show More
View Publication Preview PDF
Scopus (2)
Scopus Crossref
Publication Date
Mon Jan 08 2018
Journal Name
International Journal Of Science And Research
effect of steel fiber type on compressive strength and modules of rupture on reactive powder concrete
...Show More Authors

Publication Date
Sat Aug 21 2021
Journal Name
Engineering, Technology & Applied Science Research
The Impact of Hybrid Fibers on Punching Shear Strength of Concrete Flat Plates Exposed to Fire
...Show More Authors

This study presents an investigation about the effect of fire flame on the punching shear strength of hybrid fiber reinforced concrete flat plates. The main considered parameters are the fiber type (steel or glass) and the burning steady-state temperatures (500 and 600°C). A total of 9 half-scale flat plate specimens of dimensions 1500mm×1500mm×100mm and 1.5% fiber volume fraction were cast and divided into 3 groups. Each group consisted of 3 specimens that were identical to those in the other groups. The specimens of the second and the third groups were subjected to fire flame influence for 1 hour and steady-state temperature of 500 and 600°C respectively. Regarding the cooling process, water sprinkling was applied directly aft

... Show More
View Publication
Crossref (11)
Crossref