Preferred Language
Articles
/
jbcd-152
The effect of thermocycling and debonding time on the shear bond strength of different orthodontic brackets bonded with light-emitting diode adhesive (In vitro study)
...Show More Authors

Background: Thermocycling simulates the temperature dynamics in the oral environment. This in vitro study done to measure and compare the effect of thermocycling on the shear bond strength of stainless steel and sapphire brackets bonded to human enamel teeth using light cured orthodontic adhesive and debonded at various time, and to measure adhesive remnant index after debonding. Materials and Methods: one-hundred-twenty extracted upper first premolars for orthodontic reason were used in this study; depending on weather thermocycled or not, the sample was divided into two main groups, then within each group 30 teeth were used for stainless-steel brackets (Bionic®) and for sapphire brackets (Pure®). Both groups were subdivided into three groups (n = 10) according to the debond times: I: debond after 24 hour, II: debond after 7 days and III: debond after 30 days. Within 24 hr, half of the sample was thermocycled manually for 500 complete cycles between 5/55°C and the remaining sample was stored in distilled water at room temperature and water was changed daily until debond time for each group was performed. The adhesive remnant index was tested under 20X magnification lens using stereomicroscope. Results and Conclusions: Both bracket types demonstrated high shear bond strength values before thermocycling (P?0.05), whereas after 500 thermocycles, there were significant changes in shear bond strength resulted in marked reduction in the stainless steel brackets than in the sapphire brackets (P?0.05). Shear bond strength values increased with time for both stainless steel and sapphire brackets with and without thermocycling (P?0.05). The tendency of bond failure was increased at the bracket/adhesive interface rather than enamel/bracket interface in the stainless steel brackets whereas at the enamel/bracket interface rather than bracket/adhesive interface in the sapphire brackets.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Thu Sep 01 2016
Journal Name
Journal Of Engineering
Effect of Using Porcelanite as Partial Replacement of Fine Aggregate on Roller Compacted Concrete with Different Curing Methods
...Show More Authors

Roller-Compacted Concrete is a no-slump concrete, with no reinforcing steel, no forms, no finishing and wet enough to support compaction by vibratory rollers. Due to the effect of curing on properties and durability of concrete, the main purpose of this research is to study the effect of various curing methods (air curing, 7 days water curing, and permanent water curing) and porcelanite (local material used as an Internal Curing agent) with different replacement percentages of fine aggregate (volumetric replacement) on some properties of Roller-Compacted Concrete and to explore the possibility of introducing practical Roller-Compacted Concrete for road pavement with minimum requirement of curing. Specimens were sawed fro

... Show More
View Publication Preview PDF
Publication Date
Thu Sep 07 2023
Journal Name
Haya: The Saudi Journal Of Life Sciences
In Vitro Assessment of the Effects of Varying Dosages of Alexandrite Laser on the Development of Staphylococcus Aureus
...Show More Authors

Background: This study aimed to apply a high-power pulsed alexandrite laser in vitro, the researchers tested different exposure periods, pulse lengths, and laser fluencies to see which dosage was most successful against S. aureus bacteria, which had developed resistance to many antibiotics. Method: Three bacteria samples were exposed to laser beams for 30 seconds with a 5ms pulse duration and a laser fluency of 5J/cm2. The process was repeated with laser fluencies of 10, 15, and 20. Results: The study was carried out by using different doses of Alexandrite laser. Results: There are significant differences (p = 0.05) in the mean number of bacteria colonies exposed for 30 and 60 seconds at any laser fluencies utilized in the present i

... Show More
View Publication
Crossref
Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
A study of the Effect of Air Inlet and Exit on Indoor Air Movement
...Show More Authors

This work consists of a numerical simulation to predict the velocity and temperature distributions, and an experimental work to visualize the air flow in a room model. The numerical work is based on non-isothermal, incompressible, three dimensional, k turbulence model, and solved using a computational fluid dynamic (CFD) approach, involving finite volume technique to solve continuity, momentum and energy equations, that governs the room’s turbulent flow domain. The experimental study was performed using (1/5) scaled room model of the actual dimensions of the room to simulate room air flow and visualize the flow pattern using smoke generated  from burnt herbs and collected in a smoke generator to delivered through

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Nov 05 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Bacteriological and Chemical Study on the Effect of Lead in Blood and Saliva of Workers at Batteries Industry in Baghdad
...Show More Authors

Objectives: The study aims at:
1- Measuring the level of lead in workers’ saliva and blood in the factory.
2- Studying the correlation between the saliva lead level and the infection that caused by microorganisms, isolation and
identification.
3-Studying the influence of high blood lead level on the total white blood cells.
Methodology: This study has been conducted for the period from March 15th, 2010 to May, 20th
, 2010. A total of (60)
saliva and blood samples were collected from workers in batteries industry factory in Baghdad and another (20) samples
were collected as a control group. Lead level had been measured in blood and saliva samples, then microorganisms were
isolated the from the saliva samples.

... Show More
View Publication Preview PDF
Publication Date
Tue Dec 31 2013
Journal Name
Al-khwarizmi Engineering Journal
Thermo-Rheological Investigation and Modeling of the Shear Viscosity of Polypropylene above the Melting Temperature
...Show More Authors

The increasing use of polymeric materials in the daily life, leads to challenges in the processing industry to deliver high performance materials with affordable terms. However, new processing techniques lead to high costs. In order to reduce processing costs it is necessary to understand the non-Newtonian behavior of the polymers in their molten state to be able to simulate the processes before the construction of the plants starts. Here the shear thinning behavior of the viscosity of polymeric melts is essential. Thus, this paper deals with the experimental investigation of the thermo-rheological behavior of the viscosity of one of the most used polymers (Polypropylene) over a wide range of temperatures and shear rates.  Furthermo

... Show More
View Publication Preview PDF
Publication Date
Sun Mar 25 2018
Journal Name
Biomedical And Pharmacology Journal
Apical Extrusion of Debris and Irrigants After using Different Irrigation Needles and Systems With Different Depth of Penetration (A Comparative Study)
...Show More Authors

View Publication
Crossref (5)
Crossref
Publication Date
Thu Oct 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Relationship between the central government and local governments in the light of the centralized and decentralized administrative
...Show More Authors

Gaining the relationship between the central government and local governments is great importance especially after the expanded functions of the central government and became unable to carry out their works without all that delegate or transfer parts of its powers to lower levels.

The aims of the research is  to determine the relationship of the central government with the local government in accordance with the principle of administrative decentralization with the presentation of the competent authorities, the control of local governments, according to the Provincial Council Act No. 21 of 2008 amended.

The research has a problem that has been the relationship of the central

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Mar 15 2023
Journal Name
Journal Of Baghdad College Of Dentistry
Crystallization firing effect on the marginal discrepancy of the IPS. emax CAD crowns using two different CAD/CAM systems
...Show More Authors

Background: Marginal adaptation is critical for long – term success of crown and bridge restoration. Computer aided design / computer aided manufacture (CAD/ CAM) system is gaining more importance in the fabrication of dental restoration. Objective: The aim of this study is to evaluate the effect of crystallization firing on the vertical marginal gap of IPS. emax CAD crowns which fabricated with two different CAD/CAM systems .Materials and Methods: Twenty IPS e.max CAD crowns were fabricated. We had two major groups (A, B) (10 crowns for each group) according to the CAD/CAM system being used: Group A: fabricated with Imes - Icore CAD/CAM system; Group B: fabricated with In Lab Sirona CAD/CAM system. Each group was subdivided into two s

... Show More
View Publication Preview PDF
Scopus (7)
Crossref (3)
Scopus Crossref
Publication Date
Mon Apr 20 2026
Journal Name
ريمار
The Function of Time in Hebrew Children's Fiction
...Show More Authors

This research examines the use of time in Hebrew children's literature and how historical narratives about the biblical period and beyond formed an arena for narrative conflict between the 1960s and the mid-1980s. The research clarifies the nature of narrative time: the time of events within the story itself (the sequence of events، the rhythm، and the occasional shifts between past and present)، as well as the framing time، which is the historical period the narrator perceives as the backdrop to the narrative. It also explores the time of memory and the use of flashbacks، evocations، or temporal allusions that connect young readers to a collective past. Our research also addresses how Zionist narratives began to lose credibility afte

... Show More
Publication Date
Wed Mar 01 2017
Journal Name
Diyala Journal Of Engineering Sciences
NFLUENCE OF WATER SOURCE ON COMPRESSIVE STRENGTH OF HIGH STRENGTH CONCRETE
...Show More Authors

This research studies the influence of water source on the compressive strength of high strength concrete. Four types of water source were adopted in both mixing and curing process these are river, tap, well and drainage water (all from Iraq-Diyala governorate). Chemical analysis was carried out for all types of the used water including (pH, total dissolved solids (TDS), Turbidity, chloride, total suspended solid (TSS), and sulfates). Depending on the chemical analysis results, it was found that for all adopted sources the chemical compositions was within the ASTM C 1602/C 1602M-04 limits and can be satisfactorily used in concrete mixtures. Mixture of high strength concrete for compressive strength of (60 MPa) was designed and checked using

... Show More