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.
The article examines metaphors as one of the fundamental means used by D. Rubina when writing the novel “Parsley Syndrome” to form images of dolls as equal heroes of the work. The author of the article continues research related to the work of Dina Ilinichna Rubina, a representative of modern Russian prose.
Abstract
This research aims to examine the correlation and the influence of Authentic Leadership on the contextual performance as a dependent variable, in the departments and Division of the iraqi Ministry of Foreign Affairs To try out with a number of recommendations that contribute to raising the level of contextual performance in the Ministry. Starting from the importance of research in public organizations and its Role in society, the researcher adopted the descriptive analytical approach in accomplishing this research, The 99 people responded exclusively comprehensively, based on questionnaire that is include 28-item, using interviews and field observations as
... Show More
Millions of pilgrims and visitors from numerous parts of the world flock to Karbala (one of the most prominent ideological and religious places in central Iraq) each year to visit the holy shrines in Karbala due to their sanctity. Many improvements have been made to the Two Holy Shrines (THS), the Shrines of Imam Husayn and Imam Abbas, and the area between them (ATHS), due to the high temperatures in this region and to improve pedestrian thermal comfort. Studies on improving outdoor thermal comfort in Karbala are scarce. Hence, this research aims to look into historical and current architectural changes and how they affect thermal comfort. On the hottest summer day, the ENVI-met software program was used to simulate the building des
... Show More
(14)
Background: Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) is still a severe threaft for human health currently, and the researches about it is a focus topic worldwide.
Aim of the study: In this study, we will collect some laboratory results of the patients with coronavirus disease (COVID-19) to assess the function of liver, heart, kidney and even pancreas.
Subjects and Methods: Laboratory results of the patients with COVID-19 are collected. The biochemical indices are classified and used to assess the according function of liver, heart, kidney; meantime, and blood glucose is also observed and taken as an index to roughly evaluate pancreas.
Results: There were some in
... Show More
(1)
(5)
(2)
The effects of three different additives formulations namely Lubrizol 21001, HiTEC 8722B and HiTEC 340 on the efficiency of VII namely OCP of three base lubricating oils namely 40 stock and 60 stock and 150 stock at four temperatures 40, 60, 80 and 100oC were investigated. The efficiency of OCP is decreased when blended with 4 and 8 wt% of Lubrizol 21001 for all the three base oil types. But it is increased when adding 4 wt% and 8 wt% of H-8722B in 40 stock. While for 60 stock and 150 stock the OCP efficiency decreased by adding 4 and 8 wt% of H-8722B. In the other hand, it is decreased with a high percentage by adding 4 and 8 wt% of H-340 for 60 stock and 150 stock and for 40 stock it is increased by adding 4 wt% of H-340 and decreased
... Show More
The study of triples seeks to deal with the comprehensive nature of the Qur’an texts, and the choice fell on the trilogy of great torment, pain, and humiliation in the Noble Qur’an - an objective study, the title of this research, in which I tried to shed light on these terms, and the nuances between them, and in particular torment The eschatological terminology varied, which can be summed up in three terms, namely the great, the painful, and the offensive. The types of torment, the pain is the painful one that is described by the severity of pain and its horror, as for the humiliating punishment, it is that which humiliates the one who has fallen on it, and the diversity of torment is due to the diversity of sins.
Abstract
The image of the soldier, as a hero who sacrifices everything to defend his
country and values, is no longer depicted in modern drama. With two World Wars
and many regional wars and civil wars, the soldier becomes a victim, not a hero.
Authors present the character of the soldier as a man who suffers a lot as he is
victimized by his own government and its politics that forces him to be in such a
position. Dramatists express their views about race, oppression and war through
their characters, such as the character of the soldier, as in the two selected plays for
this research: The Hostage by Brendan Behan and A Soldier's Play by Charles
Fuller.
The Hostage depicts, through its events, the Irish oppre
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
Luqman's story stated that human instinct, if I was brought up properly, reaches wisdom and inflicts the right to everything. It is to go to worship God and adhere to the satisfaction of morals and high morals that are ordered to meet among human beings in this life, because this worship educates in the soul the most beautiful morals needed by human beings of honesty, honesty and modesty, and the work of good and virtues, and distancing the soul from evil and vices.