Preferred Language
Articles
/
3Yath4YBIXToZYALxIzt
Behavior of Post-Tensioned Concrete Girders Subject to Partially Strand Damage and Strengthened by NSM-CFRP Composites
...Show More Authors

Studies on the flexural behavior of post-tensioned beams subjected to strand damage and strengthened with near-surface mounted (NSM) technique using carbon fiber-reinforced polymer (CFRP) are limited and fail to examine the effect of CFRP laminates on strand strain and strengthening efficiency systematically. Furthermore, a design approach for UPC structures in existing design guidelines for FRP strengthening techniques is lacking. Hence, the behavior of post-tensioned beams strengthened with NSM-CFRP laminates after partial strand damage is investigated in this study. The testing program consists of seven post-tensioned beams strengthened by NSM-CFRP laminates with three partial strand damage ratios (14.3% symmetrical damage, 14.3% asymmetric damage, and 28.6% symmetrical damage). The experimental results showed that the use of CFRP laminates significantly increases the flexural capacity by up to 17.4 to 20.4%, corresponding to a strand damage ratio of 14.3 and 28.6%, respectively, enhances the stiffness, and reduces strand strain by up to 15.8 to 22.2%. However, the flexural stiffness of strengthened beams during serviceability phases is critical as strand damage ratios increase. Additionally, semi-empirical equations were proposed to predict the actual strain of unbonded strands whilst considering the effects of CFRP laminates. The suggested equations provide accurate predictions with little variance. Doi: 10.28991/CEJ-2022-08-07-013 Full Text: PDF

Scopus Clarivate Crossref
Publication Date
Thu Apr 27 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Photoconductivity of An Inorganic /Organic Composites Containing Dye-Sensitized (Zinc Oxide)
...Show More Authors

   In this paper we study the effect of adding Zinc Oxide powder (ZnO) at different ratios (10%,20%,30%,40%,50%) as particles and organic dyes rhodamine B(RhB), rohdamine 6G(Rh6G) and eosin(EO) are added at different doping ratios to polystyrene (PS), to form photosensitized(PS/ZnO/dye) composites, for samples were prepared as films by spin method. Photoconductive properties are investigated.     For I-V characteristic measurements, the photocurrent (Iph) and dark current (Id) are generally increased in non linear behavior with increasing light intensity and applied voltage for all composites. The photocurrent goes decrease through its maximum value at high white light intensities or high voltage for 2.4*10-

... Show More
View Publication Preview PDF
Publication Date
Thu Feb 01 2024
Journal Name
Baghdad Science Journal
Comparative Study of Gamma- Ray Shielding Parameters for Different Epoxy Composites
...Show More Authors

In the current work various types of epoxy composites were added to concrete to enhance its effectiveness as a gamma- ray shield. Four epoxy samples of (E/clay/B4C) S1, (E/Mag/B4C) S2, (EPIL) S3 and (Ep) S4 were used in a comparative study of gamma radiation attenuation properties of these shields that calculating using Mont Carlo code (MCNP-5). Adopting Win X-com software and Artificial Neural Network (ANN), µ/ρ revealed great compliance with MCNP-5. By applying (µ/ρ) output for gamma at different energies, HVL, TVL and MFP have been also estimated. ANN technique was simulated to estimate (µ/ρ) and dose rates. According to the results, µ/ρ of all epoxy samples scored higher than standard concrete. Both S2 and S3 samples having h

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Crossref
Publication Date
Sun Mar 07 2010
Journal Name
Baghdad Science Journal
Kinetic studies of AST isoenzymes I,II,III,IV partially purified from patient,s urine with chroinc renal failure
...Show More Authors

In this research, the kinetic studies of four isoenzymes of Asprtate aminotransferase, which partially purified from the urine of chronic renal failure patients were carried out .The four isoenzymes were obeyed Michaelis-Menton's equation and the optimum concentration of their substrate (Aspartic acid) was (166.5x10-3) mole/liter,and their Km values were determined. Four isoenzymesI,II,III,IV have shown an optimum pH at 7.4.The four isoenzymes obeyed Arrhenius equation up to 37º C and their Ea and Q10 constants were determined .

View Publication Preview PDF
Crossref
Publication Date
Tue Oct 30 2018
Journal Name
Journal Of Engineering
Statistical Equations to Estimate the In-situ Concrete Compressive Strength from Non-destructive Tests
...Show More Authors

The aim of this study is to propose reliable equations to estimate the in-situ concrete compressive strength from the non-destructive test. Three equations were proposed: the first equation considers the number of rebound hummer only, the second equation consider the ultrasonic pulse velocity only, and the third equation combines the number of rebound hummer and the ultrasonic pulse velocity. The proposed equations were derived from non-linear regression analysis and they were calibrated with the test results of 372 concrete specimens compiled from the literature. The performance of the proposed equations was tested by comparing their strength estimations with those of related existing equations from literature. Comparis

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Sun Sep 01 2024
Journal Name
Results In Engineering
Push-out test of eco-friendly steel-concrete–steel composite sections enhanced by polypropylene fibers: An experimental study and statistical analysis
...Show More Authors

Steel-concrete-steel (SCS) structural element solutions are rising due to their advantages over conventional reinforced concrete in terms of cost and strength. The impact of SCS sections with various core materials on the structural performance of composites has not yet been fully explored experimentally, and in this work, both slag and polypropylene fibers were incorporated in producing eco-friendly steel-concrete-steel composite sections. This study examined the ductility, ultimate strength, failure modes, and energy absorption capacities of steel-concrete-steel filled with eco-friendly concrete, enhanced by polypropylene fiber (PPF) to understand its impact on modern structural projects. Eco-friendly concrete was produced by the partial

... Show More
View Publication Preview PDF
Scopus (5)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Sun Oct 01 2023
Journal Name
History Of Medicine
Study of the quality of attach algae to the concrete supports of some bridges within Baghdad city
...Show More Authors

A study of taxonomic quality of algae attaching Three concert bridges built on the Tigris River within city of Baghdad including Al-Jadriyah Bridge in Al-Jadriyah area and the Bab Al-Mu'adam Bridge in Al-Shalajiya area, while the third site included Al-Muthanna Bridge in north of Baghdad city, for the period from Autumn 2021 and Winter 2022. The study identified 114 species of 32 Genus in which the predominance of Bacillariophceae (74 species, 14 Genus) Followed by Cyanophyceae (30species, 12 Genus) and 10 species (6 Genus) of Chlorophyceae. The study showed an increase in species of Bacillariophceae, Cyanophyceae which has the ability to secretion gelatinous substances that enable it to stick to solid stand, the number of the larges

... Show More
Preview PDF
Publication Date
Mon Jun 27 2022
Journal Name
Al-rafidain Journal Of Medical Sciences ( Issn: 2789-3219 )
Self-Reported Sleep Disorder, Anxiety and Depression in Iraqi Patients Post-Myocardial Infraction
...Show More Authors

Background: Myocardial infarction (MI) is distinguished by the necrosis of myocardial cells as a result of substantial and prolonged ischemia. Anxiety, problems sleeping, and feelings of depression are some of the most common psychosocial consequences of having a myocardial infarction. Aim: The purpose of this study is to evaluate the effects of post-myocardial infarction on patients' levels of anxiety, depression, and quality of sleep. Method: The collection of data from 94 individuals with MI was carried out according to a descriptive cross-sectional design. Sleep quality, depression, and anxiety were evaluated using standard questionnaires. Results: 69.1% of the participants reported having trouble getting quality sleep. The perc

... Show More
View Publication Preview PDF
Scopus (1)
Crossref (2)
Scopus Crossref
Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Engineering
The Effect of Recycled Heating and Cooling and The Effect of The Speciment Size on The Compressive Strength of Concrete Exposed To High Temperature
...Show More Authors

     In the present work effect of recycled heating and cooling on the values of concrete compressive strength due to high temperature of 4000C was studied.

    The tests show that the percent of reduction in compressive strength of the samples which exposed to a temperature of 4000C for one cycle was 32.5%, while the reduction was 52.7% for the samples which were exposed to recycled heating and cooling of ten times .      

   Moreover a study of the effect of specimen sizes on the percentages of compressive strength reduction due to high temperature

... Show More
View Publication Preview PDF
Publication Date
Sat Oct 01 2022
Journal Name
Journal Of Engineering
Production Load–bearing Concrete Masonry Units by Using Recycled Waste Crushed Clay Bricks; A Review
...Show More Authors

There are serious environmental problems in all countries of the world, due to the waste material such as crushed clay bricks (CCB) and in huge quantities resulting from the demolition of buildings. In order to reduce the effects of this problem as well as to preserve natural resources, it is possible to work on recycling (CCB) and to use it in the manufacture of environmentally friendly loaded building units by replacing percentages in coarse aggregate by volume. It can be used as a powder and replacing of percentages in cement by weight and study the effect on the physical and mechanical properties of the concrete and the masonry unit. Evaluation of its performance through workability, dry density, compressive strength, thermal conduct

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
Effect of UV radiation on dielectric properties of PU/nano-TiO2 composites
...Show More Authors

The dielectric constant of most polymers is very low; the addition of TiO2 particles into the polymers provides an attractive and promising way to reach a high dielectric constant. Polymer-based materials with a high dielectric constant show great potential for energy storage applications. Four samples were prepared, one of them was polyurethane (PU) and the other were PU with different weight percent (wt %) of TiO2 (0.1, 0.2, 0.3) powder AFM test was used to distinguish the nanoparticles. The result shows that the most shape of these nanoparticles are spherical and the roughness average is 0.798 nm. The dielectric properties were measured for all samples before and after the exposure to the UV radiation. The result illustrates that the

... Show More
View Publication Preview PDF
Crossref