Abstract: Objectives: To investigate the effect of temperature elevation on the bonding strength of resin cement to the zirconia ceramic using fractional CO2 laser. Background: Fractional CO2 laser is an effective surface treatment of zirconia ceramic, as it increases the bonding strength of zirconia to resin cement. Methods: Thirty sintered zirconia discs (10 mm diameter, 2 mm thickness) were prepared and divided to three groups (N=10) and five diffident pulse durations were used in each group (0.1, 0.5, 1, 5 and 10 ms). Group A was treated with 10 W power setting, group B with 20 W and group C with 30 W. During laser irradiation, temperature elevation measurement was recorded for each specimen. Luting cement was bonded to the treated zirconia surfaces and cured for 30 seconds. Shear bond strength was evaluated by a testing machine (universal) with bond failure mode determination. Results: The lowest temperature elevation measurement of the irradiated specimen which gave maximum shear bond strength was about 1.6±0.3 Ċ higher than ambient room temperature (27±0.2 ºC). Apparent micromechanical irregularities were seen in the treated samples and cracks formation with increased pulse duration and power setting were also observed. Conclusions: The temperature elevation is a vital factor in the surface roughness of zirconia ceramic with fractional CO2 laser irradiation and the lowest temperature elevation at best shear bond strength of zirconia ceramic to the resin cement is satisfied with the shorter pulse duration of 0.1 millisecond.
This research sought to detect the level of organizational culture prevailing in the Integrity Commission as well as the level of the organizational citizenship behavior of staff of the Commission and the impact of organizational culture in these behaviors. To achieve the objectives of the research and test the validity of hypotheses have been used questionnaire derived from measurements ready modern researchers foreigners have been adapted to suit the Iraqi environment, have been distributed (189) questionnaire on the number of employees from the Integrity Commission, which represented the research sample where the research community has a number is (1365) employees in the Baghdad was the use of a number of statistical met
... Show More
(1)
In this paper we have dealt with the word " בַּיִת" in the Book of Joshua because it makes one of those that highly employed the word בַּיִת" " in the Old Testament. The Book of Joshua comes sixth in the order of tanakh wich was written by Joshua son of Noon in Palestine during the fifteenth century B.C. and it covers a three-decade era extending from the death of Moses til the death of Joshua son of Noon.
The word " בַּיִת " in this paper refers to the place, where expressions are made by a noun modified by a noun . The modifier is"" בַּיִת , and the modified is another noun. Herein, we
... Show MoreInternational relations scholars have increasingly debated the evolving landscape of actors that challenge the traditional state-centric world order. A key element of this transformation is the rise of sub-state actors, which engages in alternative diplomacy parallel to the state, transcending traditional state-centric frameworks. This paper explores the significant shifts in international actorness over the late 20th century, focusing on the emergence and implications of sub-state diplomacy, or "paradiplomacy." First, the study introduces sub-state actors and their role in challenging the dominant state-centric discourse. It then examines the dynamic evolution of paradiplomacy, highlighting how sub-states have expanded their global
... Show More
(12)
(11)
This study focuses on the basics of cultivation and production of the Wheat Crop in
Wasit Province ; in order to reveal the reality of the geographical distribution of its cultivation
and production.
Wheat is the most important field crops cultivated in Wasit province, as it has vast
possibilities for expansion in growing and production, in which agriculture conducted in a
year and left in other , then changing this method would increase cultivated area of it to nearly
doubled, as well as the possibility of increasing average yields in Donam by using improved
seeds, fertilizer, with the availability of water lever machines, especially wheat is grown in
areas of rivers abutment.
The study showed the spread of th
Increased epidemic when Akbari in his book Explanation in the expression of the Koran
(69)
(41)
The aim of the present work, was measuring of uranium concentrations in 25 soil samples from five locations of Al-Kut city. The samples taken from different depths ranged from soil surface to 60cm step 15 cm, for this measurement of uranium concentrations .The most widely used technique SSNTDs was chosen to be the measurement technique. Results showed that the higher concentrations were in Hai Al- Kafaat which recorded 1.49 ± 0.054 ppm . The uranium content in soil samples were less than permissible limit of UNSCEAR(11.7ppm).
(1)