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.
(15)
(12)
(11)
The aim of this work was to develop and validate a rapid and low cost method for estimation of ibuprofen in pharmaceutical suspensions using Reverse-Phase High Performance Liquid Chromatography. The proposed method was conducted and validated according to International Conference on Harmonization (ICH) requirements. The chromatographic parameters were as follows: column of octyldecylsilyl C18 with dimensions (150 × 4.6) mm, mobile phase composed of acetonitrile with phosphoric acid with a ratio of 50 to 50 each using isocratic mode, flow rate of 1.5 mL/min and injection volume of 5 μL. The detection was carried out using UV detector at 220 nm. The method was validated and showed short retention time for ibuprofen peak at 7.651 min, wit
... Show More
(2)
(1)
The study aimed to reveal the degree of inclusion of media concepts in the books of social and national studies in general education in light of the criteria of media education and the nature of the Saudi society. Additionally, to identify the estimations of the participants in the study of the importance of including media concepts in these books, and to build a matrix of the range and sequence of media concepts in the books of social and national studies in the grades of Saudi general education. The study followed the descriptive approach in both descriptive analysis of the textbooks and descriptive survey of the study participants who were (203) students in the schools of boys and girls in general education in Makkah. The study used t
... Show MoreMercury, arsenic, cadmium and lead, were measured in sediment samples of river and marine environmental of Basra governorate in southern of Iraq. Sixteen sites of sediment were selected and distributed along Shatt Al-Arab River and the Iraqi marine environment. The samples were distributed among one station on Euphrates River before its confluence with Tigris River and Shatt Al-Arab formation, seven stations along Shatt Al-Arab River and eight stations were selected from the Iraqi marine region. All samples were collected from surface sediment in low tide time. ICP technique was used for the determination of mercury and arsenic for all samples, while cadmium and lead were measured for the same samples by using Atomic Absorption Spectrosc
... Show More
(11)
(6)
(6)
This work aimed to estimate the frequency of mitochondrial inborn errors of metabolism (MIEMs) in patients presenting with family history and IEM-picture who referred for advance IEM assay in Mosul province and Kurdistan region. This study was observational study conducted on 364 cases referred from different general /or private pediatric clinics with unexplained sign and symptoms and suspension of mitochondrial dysfunction. The study included 364 children with an age ranging from 1 month to 1 year. Started from January 2018 to January 2020. All patients referred with their full history review, notes about their clinical examination, and laboratory investigations including blood ammonia, serum lactate/ pyruvate, arterial blood gases. In
... Show More
(3)
Text science presented a set of criteria to make the text essentially a project to create
texts and use. Me and means of cohesion script text scientists, two standard foundries and
knitting. Find this means their equivalent in the Arab rhetorical Heritage has been found, it
means foundries find Accompanying represented (link grammar in the classroom and link),
and referrals represented by (Baldmair, Ldefinition, and the name of the signal), and
deletion, and repetition, and presentation delays. As in the standard knitting it has confirmed
Albulagjun Arabs on the semantic consistency between the text components, as reflected in
the moral link in Chapter interfaces, as well as in moral coherence between parts of the te
This study aims to explain the purposes of thinking in light of the Holy Qur’an. The study adopted the deductive method by analyzing the meanings of the eighteen thinking verses mentioned in the Holy Qur’an That is by referring to the ancient and contemporary book interpretations and inferring the purposes of thinking from the context of those verses. The study concluded that there are seven main purposes, for thinking in the light of the Holy Qur’an, are understanding the universal regulations, contemplating the social codes, inferring, extracting maxims and meanings from the Qur’anic proverbs, analyzing the situation objectively, balancing between interests and evils, and freeing the mind from the authority of the paranormal. T
... Show More