Preferred Language
Articles
/
jbcd-656
The effect of ER: YAG laser on enamel resistance to caries during orthodontic treatment: An in vitro study
...Show More Authors

Background: One common undesirable side effect of orthodontic treatment with fixed appliances is the development of incipient caries lesions around brackets, particularly in patients with poor oral hygiene. Different methods have been used to prevent demineralization; the recent effort to improve the resistance against the demineralization is by the application of lasers. Materials and method: Thirty human premolars extracted for orthodontic purposes were used to test the effect of two energy level of ER-YAG laser on enamel resistance to demineralization. The brackets were bonded on the teeth and all the labial surface excluding 2 mm area gingival to the brackets were painted with acid resistance varnish. Three groups were generated. The first group was the control group (A), with no treatment was performed. In group II (B)and groups III (C); teeth were irradiated by ER-YAG laser of 200, 60 mj energy respectively. All the teeth were individually subjected to acid challenge cycle for 30 days. After debonding longitudinal sections were taken and examined under stereomicroscope. The enamel demineralization evaluation was done by taking the average of three depths at the centre of the artificial lesion. Also the enamel surface was classified by an experienced investigator according to acid etch pattern. Comparisons of the average depth values of the groups were performed with ANOVA and LSD tests. The statistical significance level was set at p ≤ 0.05. Results: The results revealed that average lesion depth was significantly deeper at the control group than the laser groups, and its significantly deeper in group (B) 200 mj than in group (C) 60 mj, enamel surfaces showed deeper pits and craters than in control group. Conclusions: the decrease in artificial caries lesion depth associated with use of the two laser energy level support the ER-YAG laser as a tool to increase enamel resistance to demineralization and white spot lesion prevention. Key words: Demineralization, ER-YAG, laser.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Jul 01 2018
Journal Name
Journal Of Educational And Psychological Researches
Slums and its implication on security in Baghdad
...Show More Authors

The research team seeks to study the phenomena of random housing in Iraqi society in general and Baghdad city in particular by standing on the causes behind this phenomena and its relation with security situation in Baghdad. The researchers adopted a theoretical and practical framework. The main objective is to diagnose the risks caused by the escalation of slums in Baghdad city. 

View Publication Preview PDF
Publication Date
Wed Mar 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
Using Quadratic Form Ratio Multiple Test to Estimate Linear Regression Model Parameters in Big Data with Application: Child Labor in Iraq
...Show More Authors

              The current paper proposes a new estimator for the linear regression model parameters under Big Data circumstances.  From the diversity of Big Data variables comes many challenges that  can be interesting to the  researchers who try their best to find new and novel methods to estimate the parameters of linear regression model. Data has been collected by Central Statistical Organization IRAQ, and the child labor in Iraq has been chosen as data. Child labor is the most vital phenomena that both society and education are suffering from and it affects the future of our next generation. Two methods have been selected to estimate the parameter

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Dec 31 2020
Journal Name
Iraqi Journal Of Market Research And Consumer Protection
SIMULATION AND MODELING OF HYDRO CRACKING REACTR TO REDUCE POLLUTION CAUSED BY REFINERIES: SIMULATION AND MODELING OF HYDRO CRACKING REACTR TO REDUCE POLLUTION CAUSED BY REFINERIES
...Show More Authors

Hydro cracking of heavy oil is used in refinery to produce invaluable products. In this research, a model of hydro cracking reactor has been used to study the behavior of heavy oil in hydro cracking under the conditions recommended by literature in terms lumping of feed and products. The lumping scheme is based on five lumps include: heavy oil, vacuum oil, distillates, naphtha and gases. The first order kinetics was assumed for the conversion in the model and the system is modeled as an isothermal tubular reactor. MATLAB 6.1 was used to solve the model for a five lump scheme for different values of feed velocity, and temperature.

View Publication Preview PDF
Publication Date
Fri Dec 31 2021
Journal Name
Political Sciences Journal
Pakistan: The most dangerous terrorist extremism hotbed (a study information, limitations, and factors)
...Show More Authors

   Receipt date:10/27/2021    accepted date:12/15/2021     Publication date:31/12/2021

        Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 International License.

The phenomenon of extremist extremism (terrorism) was one of the most prominent issues that took a large space in the twenty-first century, in which cognitive motives were mixed with strategic and ideological motives, leading to the emergence of terrorist extremi

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Nov 01 2021
Journal Name
Proceedings Of First International Conference On Mathematical Modeling And Computational Science: Icmmcs 2020
Study the Stability for Ordinary Differential Equations Using New Techniques via Numerical Methods
...Show More Authors

Nonlinear differential equation stability is a very important feature of applied mathematics, as it has a wide variety of applications in both practical and physical life problems. The major object of the manuscript is to discuss and apply several techniques using modify the Krasovskii's method and the modify variable gradient method which are used to check the stability for some kinds of linear or nonlinear differential equations. Lyapunov function is constructed using the variable gradient method and Krasovskii’s method to estimate the stability of nonlinear systems. If the function of Lyapunov is positive, it implies that the nonlinear system is asymptotically stable. For the nonlinear systems, stability is still difficult even though

... Show More
Scopus (8)
Scopus
Publication Date
Sat Aug 01 2020
Journal Name
Iop Conference Series: Materials Science And Engineering
Effects of Sandy Soil-structure Interaction on the Natural Period of RC Building Frames
...Show More Authors
Abstract<p>Building natural period, T, is a key character in building response for wind and seismic induced forces. In design practice, the period, T, is either estimated from empirical relations proposed by the design codes or determined from analytical or numerical models. The effect of the soil-structure interaction is usually neglected in the design practice and analysis models. This paper uses a sophisticated finite element simulation to investigate the effect of soil-structure modeling on the fundamental period of RC buildings subjected to wind and seismic induced forces. A typical interior building frame has been imitated using the frame element for beams and columns with constrains to mo</p> ... Show More
View Publication
Scopus Crossref
Publication Date
Sat Mar 01 2008
Journal Name
Iraqi Journal Of Physics
Influence of Gold Concentration on the Main Detection Parameters of Ge-Au Photoconductive Detector
...Show More Authors

Ge-Au infrared photoconductive detection was prepared from germanium single crystal which were doped with different gold concentration using thermal evaporation. The spectral resonsivity (Rλ), spectral detectivity (D*) were determined as function of wavelength, also the resistance, conductivity in dark and with illumination to infrared radiation, the gain and relative photo response have been measured with different gold concentration. Remarkable improvements in the photoresponse gain were observed for the highest resistance specimen at the expense of spectral detectivity values.

View Publication Preview PDF
Publication Date
Tue Nov 09 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Impact Cloud Computing On The Development of Accounting Education: Evidence From Sultanate of Oman
...Show More Authors

Cloud computing is the new technological trend for future generations. It represents a new way to use IT resources more efficiently. Cloud computing is one of the most technological models for developing and exploiting infrastructure resources in the world. Under the cloud, the user no longer needs to look for major financing to purchase infrastructure equipment as companies, especially small and medium-sized ones, can get the equipment as a service, rather than buying it as a product. The idea of ​​cloud computing dates back to the sixties of the last century, but this idea did not come into actual application until the beginning of the third millennium, at the hands of technology companies such as Apple, Hp, IBM, which had

... Show More
View Publication Preview PDF
Publication Date
Fri Jan 01 2021
Journal Name
Materials Today: Proceedings
Impact of phosphate ester addition on the cytotoxicity of heat cured denture base material
...Show More Authors

This study aims to evaluate and compare the cytotoxicity and biocompatibility of a modified heat-cured acrylic denture base material containing 15% phosphoric acid 2-hydroxyethyl methacrylate ester (PA2HEME) with those of nonmodified PMMA. Discs with a diameter of 12 mm and a thickness of 2 mm were prepared using a heat-cured PMMA denture base material and divided into control and experimental groups. The experimental group was modified with 15% phosphoric acid 2-hydroxyethyl methacrylate ester (PA2HEME). The modified and nonmodified materials were tested via FTIR, and the effect of modification on surface roughness was evaluated with AFM. An in vitro test was conducted to examine the cytotoxicity and biocompatibility of heat-cured acry

... Show More
View Publication
Scopus (2)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Wed Jan 01 2025
Journal Name
Journal Of Governance And Regulation
The impact of corporate governance and audit quality on value relevance of accounting information
...Show More Authors

This study aims to investigate the relationship between corporate governance (CG) and audit quality (AQ) in the adequacy of the value relevance of accounting information (VRAI). The study sample included Iraqi firms listed on the Iraqi Stock Exchange (ISE) from 2010 to 2022. Nineteen firms were a research sample selected from 44 firms listed on the ISE. They chose to use the model (Ohlson, 1995) in measuring VRAI, which is based on measuring the absolute value of the level of value relevance to earnings per share (EPS) the absolute value of the book value suitability level VRAI. CG was measured through five factors: board size, gender of board members, independence of the board from the chief executive officer (CEO), ownership perce

... Show More
View Publication
Scopus Crossref