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 presents a study of using an additive for the objective of increasing the setting time of a material used in several aspects in the constructional field, this material is “Local-Gypsum” which is locally called “Joss”, and the additive used in this study is “Trees Glue Powder” denoted by “TGP”. Nine mixtures of Local-gypsum (joss) had been experimented in the current study to find their setting time, these mixes were divided into three groups according to their water-joss ratios (W/J) (0.3, 0.4 and 0.5), and each group was sub-divided into three sub-groups according to their TGP contents (0.0%, 0.3% and 0.6%). It was found that, when TGP is added with the
Research aims to know the impact beyond the defined in the collection. The research community is the second school students at Baghdad University and a research sample (63) students, the number of experimental group (27) students and a control group (30) students. The researcher was rewarded in variable lifetime for students and educational attainment and educational level of the parents and the educational level of mothers. The researcher has developed a test took the number of paragraphs (20). A test was true after it has been submitted to the Group of arbitrators. The test was consistent with test method used and the reliability coefficient (0, 88). Either the statistical methods used by the researcher are: Pearson correla
... Show MoreIn this research The study of Multi-level model (partial pooling model) we consider The partial pooling model which is one Multi-level models and one of the Most important models and extensive use and application in the analysis of the data .This Model characterized by the fact that the treatments take hierarchical or structural Form, in this partial pooling models, Full Maximum likelihood FML was used to estimated parameters of partial pooling models (fixed and random ), comparison between the preference of these Models, The application was on the Suspended Dust data in Iraq, The data were for four and a half years .Eight stations were selected randomly among the stations in Iraq. We use Akaik′s Informa
... Show MoreThe phenomenon of advertising In the poetry of Ali bin Abdul Rahman Balnopi Sicilian
The study aims at showing the effect of basil oil on the sensory properties of the laboratory biscuits. the results show the sensory valuation before and after the storage. the (A4) equation exceeds 15% of T exchange (3 , 4 , 5 g. basil 19 , 55 g . fats )in most of the studied sensuous qualities. Then, the (A5) equation of 20% exchange percentage (4.60g. basil oil + 18.40g. fats). Then, the (A3) equation of 10% exchange percentage (2.30g. basil oil + 20.70g. fats). Then the (A2) equation of 5% exchange percentage (1.5g. basil oil + 21.85g. fats). Finally, the control equation (A1) received the lower value of sensuous evaluation and general acceptance. Abstract differences also appeared at denotation level 0.05 between the (A2)
... Show MorePriority of road maintenance can be viewed as a process influenced by decision-makers with varying decision-making power. Each decision-maker may have their view and judgment depending on their function and responsibilities. Therefore, determining the priority of road maintenance can be thought of as a process of MCDM. Regarding the priority of road maintenance, this is a difficult MCDM problem involving uncertainty, qualitative criteria, and possible causal relationships between choice criteria. This paper aims to examine the applicability of multiple MCDM techniques, which are used for assessing the priority of road maintenance, by adapting them to this sector. Priority of road maintenance problems subject to internal
... Show MoreAbstract
This research shows the history of political conflicts in Zimbabwe, the
merits of the political struggle for power in this country since the British
colonial period, especially after the British administration announced that
Zimbabwe is a local colony of the British Crown in 1923, as the settlement
process against the wide white deprive local people to own and lease land
and low income, as well as the 1961 Constitution, which granted access to
the white powers in accordance with the authority of the top menu for the
existing lower allocated to blacks.
These events and factors led to a national rejection in Zimbabwe,
which crystallized in the form of parties and political organizations through the
This study examines the news values employed by regional news agencies in the selection and dissemination of news concerning Iraqi affairs. Content analysis was conducted on a purposive sample of 596 news articles sourced from official websites of news agencies, including Iraqi, Turkish, and Iranian agencies. The research aims to identify the underlying criteria used by these agencies in determining news suitability for publication.
Time represented a significant element in building any film story, despite its inability to express itself, but by employing the rest of the elements of the cinematic mediator language to express it. Time factor is present and manifested in all the details of the picture, and the more important is its presence in the event narration process. The narration totally depends on temporal structure in which it appears, which makes time a dominating element in the development of the narrative shapes and patterns. The narrative propositions have come to take new workings that time streams appeared that manipulate the time structure, reversing it, stopping it or making it fluctuate between the three levels of time, or repeating it or make
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