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 study aims mainly to identify the role of the use of blockchain technology in improving the quality of digital financial reports, answering questions and testing the hypothesis of the study, the researchers relied on the descriptive analytical approach, and to obtain the necessary data a questionnaire was distributed after evaluation to the study community.
The results of the study have shown that the use of blockchain technology helps to provide a high degree of reliability in digital financial reports published to banks over the Internet, ensure the speed of completion and completion, and maintain the privacy and confidentiality of the information contained in the digital financial reports of banks
... Show MoreSource of energy and protein Field crops considered an important needed for human
beings Due of this fact increases should appear in the quantities of their production in order to
meet the needs of continuous increasing in the population of the glope year after year ;
otherwise, an increase in the gap between the amount of production and consumption will
occur .
This study aims to reveal the geographical distribution of the potato crop in the district
of Abu – Ghraib. For this purpose, a study conducted about the cultivated areas, production
and crop yields per Dunam for period of 7 years lasted from 2005-2011.
The study shows that potato is one of the most important field crops that are grown in
the Abu –
Stealth marketing is considered as one of the contemporary issues that researchers have begun to explore as a current understanding. It is the marketing approach used by organizations to promote their products and services to the public in implicit and indirect manner. In this article, the concept of stealth marketing will be discussed throw its advantages and disadvantages. In addition, the different techniques of stealth marketing have been discussed including: viral marketing, celebrity marketing, brand pushers, bait-and-tease marketing, video games marketing, and marketing in music. Furthermore, a new technique of marketing entitled “Marketing through social responsibility” has been added and discussed according to the themes in the
... Show MoreThe present work included a study of benthic algae on two substrates: rocks and clay on a section of the Tigris River at the Al-Atifiyah site in the fall of 2018. The result of this study was recorded 89 species belong to 50 genus of benthic algae on both substrates and composed of Bacillariophyceae (59.6%, 61.2%), Chlorophyceae (25.8%, 20.4%) and Cyanophyceae (14.5%, 18.3%) respectively on epilithic and epipelic algae. The present study was recorded the highest total algae cell density (1173.2 cells *103/cm2) on epilithic algae while the lowest total algae cell density was recorded on epipelic algae (76.95 cells *103/gm). For measure div
A program in Visual Basic language was designed to predict the type of radio storm that emitted from Jupiter at specific Local Time (LT) from two different Iraqi locations (Baghdad and Basra), such storms result from the Central Meridian Longitude (CML) of system ??? for Jupiter and phase of Io’s satellite (?Io). Some of these storms are related to position of Io (Io- A,B,C,D) and others are unrelated (non-Io-A,B,C,D) to its position. The input parameters for this program were user specified by determining the observer’s location (longitude), year, month and day. The output program results in form of tables provides the observer with information about the date and the LT of beginning and end of each type of emitted storm. Two Io-storm r
... Show MoreThis article discusses some linguistic problems that arise when translating the Holy Quran from Arabic to Russian. We analyze lexical, syntactic and semantic problems and support them with Examples of verses from the Qur'an, since the Qur'an is the word of Allah. It contains prayers and instructions full of both literal representations and figurative comparisons. The identification of linguistic and rhetorical features challenges translators of the Holy Qur'an, especially when translating such literary devices as metaphor, assonance, epithet, irony, repetition, polysemy, metonymy, comparisons, synonymy and homonymy. The article analyzes: metaphor, metonymy, ellipsis, polysemy.
This study examined the problem of identifying the vocabulary of the methodology of teaching Arabic language in the faculties of Media. The researcher noticed the existence of an overlap between the syllabuses of the general specialization of the Arabic language and its Media sections in the universities with the special professional vocabulary that suits the study of the media student. Thus ,this study is regarded as a real attempt to present a methodological model of media language that concerns with fillfuling students ‘linguistic and knowledgeable needs relying on measuring their benefits from the methodological Arabic curriculum . Key words:problem, teaching’ methodology of Arabic language, media language.
... Show MoreThe purpose of the current research is to identify the most important problems that primary school students suffer from inside and outside the classroom from the point of view of their teachers. A sample of (100) male and female teachers was chosen from the Rusafa\ second Directorate for the academic year (2018-2019). The research tool was prepared after reviewing literature related to the issue of problems and difficulties facing students or students in the school stage and even at university. The researcher reached several results that were discussed in the fourth chapter, with a set of conclusions based on the results of the research, and come up with several recommendations and suggestions.
This research is aiming to find the effective role of the personality characteristics of the Leader in business organization entrepreneurship by studying the effect of the special dimensions of personality characteristics (neuroticism, extraversion, openness, Agreeableness, and conscientiousness) on business organizations entrepreneurship dimensions representing in the two main dimensions (entrepreneurship direction and strategic entrepreneurship) across field study was conducted in thirteen private colleges in Baghdad.
The problem of the research relies in asking the question, is there an effect for Leader personality characteristics on business organizations entrepreneurship. and statistical methods hav
... 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