Preferred Language
Articles
/
jbcd-2912
Effect of ageing media on shear bond strength of metal orthodontic brackets bonded with different adhesive systems (A comparative in-vitro study)
...Show More Authors

Background: The aim of this study was to evaluate the shear bond strength (SBS) and adhesive remnant index (ARI) of different orthodontic adhesive systems after exposure to aging media (water storage and acid challenge). Materials and methods: Eighty human upper premolar teeth were extracted for orthodontic purposes and randomly divided into two groups (40 teeth each): the first group in which the bonded teeth were stored in distilled water for 30 days at 37°C, and the second group in which the bonded teeth were subjected to acid challenge. Each group was further subdivided into four subgroups (10 teeth each) according to the type of adhesive system that would be bonded to metal brackets: either non-fluoride releasing adhesive (NFRA), fluoride releasing adhesive (FRA), Fluoride releasing bond with self-etching primer (FRBSP), or powder and liquid orthodontic fluoride releasing adhesive (PLFRA). After 30 days of water storage and acid challenge ageing procedures, the SBS was determined using Instron testing machine with a crosshead speed of 1 mm/min. The ARI was assessed using a stereomicroscope with 10 X magnification. Result: The SBS testing revealed significant differences (p< 0.05) among the four tested adhesive systems in water storage and acid challenge groups using ANOVA F-test. In both groups, the NFRA subgroup exhibited the highest mean SBS value, followed by FRASP, then FRA subgroups, while the PLFRA subgroup had the lowest value of mean SBS. The independent t-test showed non-significant differences in mean SBS values between water storage and acid challenge groups. In respect to the ARI analysis, the Chi-square test showed significant differences among the tested adhesive systems. Conclusion: The shear bond strength of the fluoride releasing adhesive system was less than that of the non-fluoride releasing adhesive system, but still above the clinically acceptable range.

 

Scopus Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Feb 01 2016
Journal Name
Journal Of Engineering
Impact of Different H/D Ratio on Axial Gas Holdup Measured by Four-Tips Optical Fiber Probe in Slurry Bubble Column
...Show More Authors

In wide range of chemical, petrochemical and energy processes, it is not possible to manage without slurry bubble column reactors. In this investigation, time average local gas holdup was recorded for three different height to diameter (H/D) ratios 3, 4 and 5 in 18" diameter slurry bubble column. Air-water-glass beads system was used with superficial velocity up to 0.24 m/s. the gas holdup was measured using 4-tips optical fiber probe technique. The results show that the axial gas holdup increases almost linearly with the superficial gas velocity in 0.08 m/s and levels off with a further increase of velocity. A comparison of the present data with those reported for other slurry bubble column having diameters larger than

... Show More
View Publication Preview PDF
Publication Date
Mon Mar 07 2022
Journal Name
Journal Of Educational And Psychological Researches
The effect of a counseling program in reducing emotional submission among intermediate school students
...Show More Authors

Emotions are part of the personality of the individual and affect many different aspects of the personality, and it is an important element of social and psychological adaptation, especially if it is within the limits of nature, and if the methods used to express them are appropriate and moderate.

Submission is one of the characteristics that express the way an individual relies upon in dealing with others and in dealing with matters of life. An individual who complies with instructions and orders and abides by them, and performs what is required of him without hesitation or delay. Adolescence is an important and accurate stage in the constructive development of an individual and in his psychological and social life.

The

... Show More
View Publication Preview PDF
Publication Date
Sat Aug 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
Developing Systems Engineering for Sustainable Infrastructure Projects
...Show More Authors
Abstract<p>Globally, Sustainability is very quickly becoming a fundamental requirement of the construction industry as it delivers its projects; whether buildings or infrastructures. Throughout more than two decades, many modeling schemes, evaluation tools, and rating systems have been introduced en route to realizing sustainable construction. Many of these, however, lack consensus on evaluation criteria, a robust scientific model that captures the logic behind their sustainability performance evaluation, and therefore experience discrepancies between rated results and actual performance. Moreover, very few of the evaluation tools available satisfactorily address infrastructure projects. The res</p> ... Show More
View Publication
Scopus (4)
Crossref (3)
Scopus Crossref
Publication Date
Fri Jan 01 2016
Journal Name
Bulletin Of Mathematics And Statistics Research
New Approximation Operators Using Mixed Degree Systems
...Show More Authors

This paper is concerned with introducing and studying the first new approximation operators using mixed degree system and second new approximation operators using mixed degree system which are the core concept in this paper. In addition, the approximations of graphs using the operators first lower and first upper are accurate then the approximations obtained by using the operators second lower and second upper sincefirst accuracy less then second accuracy. For this reason, we study in detail the properties of second lower and second upper in this paper. Furthermore, we summarize the results for the properties of approximation operators second lower and second upper when the graph G is arbitrary, serial 1, serial 2, reflexive, symmetric, tra

... Show More
View Publication Preview PDF
Publication Date
Sun Jul 01 2001
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
HAEMOPROTEIDS OF THE AVIAN FAMILY RALLIDAE IN IRAQ WITH DESCRIPTION OF A NEW SPECIES
...Show More Authors

A survey of haemoproteids among the eight species of Iraq rallids were carried out in the
middle, south, and west of Iraq. Two haemoproteods were recorded, Haeomproteus porzanae
(Galli-Valerio, 1907) as a new record for Iraq and the new species H. baghdadensis described
from Fulica atra L. collected in the middle of Iraq.

View Publication Preview PDF
Publication Date
Sat Apr 01 2023
Journal Name
Baghdad Science Journal
A Study of a-Si:H Absorption Edge Using Dunstan’s Model
...Show More Authors

The optical absorption data of Hydrogenated Amorphous Silicon was analyzed using a Dunstan model of optical absorption in amorphous semiconductors. This model introduces disorder into the band-band absorption through a linear exponential distribution of local energy gaps, and it accounts for both the Urbach and Tauc regions of the optical absorption edge.Compared to other models of similar bases, such as the O’Leary and Guerra models, it is simpler to understand mathematically and has a physical meaning. The optical absorption data of Jackson et al and Maurer et al were successfully interpreted using Dunstan’s model. Useful physical parameters are extracted especially the band to the band energy gap , which is the energy gap in the a

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Fri May 01 2020
Journal Name
Journal Of Engineering
Shrinkage and Strength Behavior of Highly Plastic Clay Improved by Brick Dust
...Show More Authors

Highly plastic soils exhibit unfavorited properties upon saturation, which produce different defects in engineering structures. Attempts were made by researchers to proffer solutions to these defects by experimenting in practical ways. This included various materials that could possibly improve the soil engineering properties and reduce environmental hazards. This paper investigates the strength behavior of highly plastic clay stabilized with brick dust. The brick dust contents were 10%, 20%, and 30% by dry weight of soil. A series of linear shrinkage and unconfined compression tests were carried out to study the effect of brick dust on the quantitative amount of shrinkage experienced by highly plastic clay and the undra

... Show More
View Publication Preview PDF
Crossref (6)
Crossref
Publication Date
Fri Aug 02 2024
Journal Name
Engineering, Technology &amp; Applied Science Research
Contributory Factors related to the Tensile Strength of Hot Mix Asphalt Concrete
...Show More Authors

Tensile strength is a critical property of Hot Mix Asphalt (HMA) pavements and is closely related to distresses such as fatigue cracking. This study aims to evaluate methods for assessing fatigue cracking in Asphalt Concrete (AC) mixes. In order to achieve optimum density at different binder contents, the mixes were compressed using a gyratory compactor. Tensile strength was assessed using the Indirect Tensile (IDT) and Semi-Circular Bend (SCB) tests. The results showed that the tensile strength measured by the SCB test was consistently higher than that measured by the IDT test at 25 °C. In addition, the SCB test showed a stronger correlation between increasing binder content and tensile strength. For binder contents ranging from 4

... Show More
View Publication
Scopus Crossref
Publication Date
Sun Dec 11 2022
Journal Name
Journal Of The College Of Basic Education
Rationalization of two strength endurance tests for juniors Ages under (16) years
...Show More Authors

Carrying strength is one of the important physical capabilities in the field of competitive sports, which affects the success of the sports training process and helps players to continue to perform skillfully, physically and tactically for as long as possible, and the capacity for endurance varies depending on the type of sports activities, it may sometimes be very short. And with a high level of intensity, such as gymnastics and wrestling movements, and it may be long, and with a medium level of intensity, as in basketball, football and other games. The research community represents a sample of Baghdad players for teams (football, basketball, handball, volleyball, wrestling, weightlifting) and for the sports season (2017-2018 AD) for ages

... Show More
Publication Date
Tue Jan 01 2019
Journal Name
Aip Conference Proceedings
Studying the partial substitution of barium with cadmium oxide and its effect on the electrical and structural properties of HgBa2Ca2Cu3O8+δ superconducting compound
...Show More Authors

View Publication
Scopus (24)
Crossref (21)
Scopus Clarivate Crossref