Background: This study was formulated to compare the effect of 5%hydrofluoric acid in comparison to 37%phosphoric acid with and without the application of silane on bond strength of composite to porcelain. Materials and Methods: Specimen preparation was divided in to two phases, metal-disks fabrication (8mm-diameter and 4mm-thickness) and ceramic veneering. Thirty two specimens were prepared, sandblasted with 50 μm aluminum oxide, and divided into four groups of eight samples. Groups I and III were etched with 37%phosphoric acid while groups II and IV were etched with 5%hydrofluoric acid; and groups I and II were silaneted while groups III and IV were not. Heliobond, and resin composite were applied to each specimen using a plastic transparent split mold (4mm- diameter and 4mm-height). Specimens were stored in distilled water for 24 hours then thermocycled for 100 cycles. Shear bond strength was determined by a Zwick universal machine at a cross-head speed 5 mm/minute. Results: Mean shear bond strength values were 21.02(group I), 23.31(group II), 4.00(group III), and 18.60(group IV). Paired-t revealed that specimens treated with 5%hydrofluoric acid were significantly higher than those treated with 37%phosphoric acid regardless the use of silane. The use of silane dramatically enhanced the bond strength of composite resin to porcelain for both acids. All specimens treated with 37%phosphoric acid without silane showed adhesive failure, while those treated with 5%hydrofluoric acid showed mostly cohesive failure within ceramic. Conclusion: Silane improved the shear bond strength of composite to ceramic, and hydrofluoric acid performed greater bond strength compared to phosphoric acid.
This paper is illustrates the sufficient conditions of the uniformly asymptotically stable and the bounded of the zero solution of fifth order nonlinear differential equation with a variable delay τ(t)
This research deal the primary and secondary sedimentary structures in the By Hassan Formation in the three locations in the northeast of Iraq. Can be recognize many geological structures such as cross bedding, planer bedding, graded bedding, channel structure and mud ball house deposit in the flood plain. The ether side this research study the direction of old current and sedimentary structure that made by the one direction current
The process of evaluating business processes, complex, repetition of procurement processes, need for raw materials and frequency of demand, which makes dealing with suppliers in the evaluation process, making the need for a process intervention in the process. Lighter on the other hand.
Many Iraqi companies suffer from problems related to suppliers, and cases of administrative and financial corruption are often raised regarding this type of contract and from this reality the necessity of researching this problem and trying to develop some solutions to reduce its impact on the companies' work, by using a method that works according to the standards adopted in Evaluation and selection of the supplier in the
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Urban planning task and the control of constructional planning and urban management for cities considers the main tasks that the government takes care off. The paper discusses the concept of power from historical view of ancient Islamic cities to discover the strategies of urban management that the Islamic city adopt and to employ it in contemporary cities ,the more problems that modern cities suffer from which appears through poorness of urban context ,belongs to the loss of balance exists between the different faces of power that takes the tasks of urban management .therefore enhancement of urban environment is being through re-back that balance in administrative structures that make the cities go ahead . So the attention has b
... Show MoreThe current study is aimed to identify personality types of the lecturers of Baghdad University as well as identify the prevailing types among the lecturers. In addition, the study aimed to identify the significant difference among personality types (The Enneagram) according to the variables of academic title and scientific major . One hundred and ninety four lecturers were involved in this study. In order to achieve the study's aims, the scale of (Baron& Wagele 1994) was used to measure the nine personality types (The Enneagram) that was translated by( Anwar Omar Ibrahim 2012). Some statistical analysis were used and the result demonstrated that Romantic types was found to be the most prevailing types among the lecturers of Baghdad
... Show MoreAutorías: Wafaa Sabah Mohammed Al-Khafaji, Fatimah Hameed Kzar Al-Masoodi, Suadad Ibrahim Suhail Al-Kinani. Localización: Revista iberoamericana de psicología del ejercicio y el deporte. Nº. 3, 2023. Artículo de Revista en Dialnet.
The phenomenon of child labor, any activity performed by a child and represents a contribution to the production, this phenomenon had been rife in Iraqi society, after that the proportion of child labor for the age group (6-14 years) amounting to 3% in 2006, became for the same age group of 8% in 2008*.
It is recognized that each phenomenon reasons, the phenomenon which our atten
... Show MoreFutsal and blind football are group games of a competitive nature due to their excitement, excitement, fun, and aesthetic goals with charming artistic touches. This explains the public's passion for these two games, whether healthy people or blind people play them, to expand their vision and knowledge. About these two games, a historical approach is presented about their origins, development, and how they became globally recognized competitive sports with unified rules and world championships at various levels. Studying the origin and global spread of both futsal and blind football and identifying the most prominent developments in the rules and tools for futsal and blind football. The most important findings were that both futsal and footb
... Show MoreThis research focuses on the epidemic of Job burnout and seeks to achieve sustainable preeminence among the employees of the University of Baghdad. It also identifies the meaning of the differences between the two genders of males and females according to the variables, and it also does the correlation between the two variables. First, the two researchers developed a test of job burnout that incorporates 18 items, which has been proven to be statistically fit. Moreover, they developed a competitive superiority measure consisting of 22 items in it, and its psychometric properties confirm their fit. The two tools were applied to a sample of 120 employees who were randomly selected from six colleges at the University of Baghdad, alongside univ
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