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.
The study aims at:
1- Identifying the contemporary educational approaches in teaching arts.
2- The effectiveness of using the visual thinking strategy in photography subject for the first year students in the institute of fine arts/Holy city of Kadhimiyah.
The study sample is made of (30 ) first year students (in the institute of fine arts/in Holy city of Kadhimiyah) distributed into two groups, an experimental group made of (15) students and a control group having the same number of students in order to conduct the test. The test for the visual thinking strategy in the subject of photography has been designed and the validity and reliability for the research tool have been verified. In order to demonstrate the results of the
The current study deals with the performance of constructed wetland (CW) incorporating a microbial fuel cell (MFC) for wastewater treatment and electricity generation. The whole unit is referred to as CW-MFC. This technique involves two treatments; the first is an aerobic treatment which occurs in the upper layer of the system (cathode section) and the second is anaerobic biological treatment in the lower layer of the system (anode section). Two types of electrode material were tested; stainless steel and graphite. Three configurations for electrodes arrangement CW-MFC were used. In the first unit of CW-MFC, the anode was graphite plate (GPa) and cathode was also graphite plate (GPc), in the second CW-MFC unit, the anode was stainless st
... Show MoreThe present study utilised date palm fibre (DPF) waste residues to adsorb Congo red (CR) dye from aqueous solutions. The features of the adsorbent, such as its surface shape, pore size, and chemical properties, were assessed with X-ray diffraction (XRD), BET, Fourier-transform infrared (FTIR), X-ray fluorescence (XRF), and field emission scanning electron microscope (FESEM). The current study employed the batch system to investigate the ideal pH to adsorb the CR dye and found that acidic pH decolourised the dye best. Extending the dye-DPF waste mixing period at 25°C reportedly removed more dye. Consequently, the influence of the starting dye and DPF waste quantity on dye removal was explored in this study. At 5 g/L dye concentration, 48% d
... Show MoreRHS Nasser, NHY Al-Afoun, SPECIALUSIS UGDYMAS, 2022
The study seeks to clarify the role of International Auditing Standard No. (320) of the relative importance in determining responsibility for planning and implementing the process of auditing financial statements and expressing neutral technical opinion through the analytical procedures of the auditor, whose responsibility is to obtain appropriate and reliable audit evidence that helps the auditor to form a general conclusion about whether The financial statements were consistent with the auditor's understanding of the entity. The relative importance contributes to defining the important accounts that help to set priorities for the auditor to set the necessary analytical procedures for these accounts. One of the most important co
... Show MoreSelect the researcher discussed problem of asking the following : Do you use visual intelligence strategy effective in the collection of students in the Department of Art Education in the foreseeable material ? The research aims to " measure the effectiveness of the strategy in the collection of visual intelligence students in the Department of Art Education in the foreseeable material ". To verify the objective of this research was identify hypotheses zero to measure the level of achievement in the foreseeable material second grade students in the Department of Art Education - Faculty of Fine Arts . The population of the research students in the Department of Art Education / Faculty of Fine Arts at the University of Baghdad who are stud
... Show MoreThe study of images in the cognitive field receives considerable attention by researchers, whether in the field of media and public relations or in other humanities. Due to the great importance in shaping trends of public opinion, especially trends that individuals and the behaviors of people, institutions or ideas are determined by forming images that they hold in their minds towards these persons or institutions. Modern enterprises have realized, whether they are governmental ministries and official departments or non-governmental organizations as civil society organizations, the importance of studying the dominant image in the minds of the masses and make decisions and draw plans to configure this image as these institutions wishes.&n
... Show MoreThe theater benefited from the concept of (hypertext) to create different virtual worlds. The four chapters of the research included the first (methodological framework), the second (theoretical framework) came in two sections (hypertext, its concepts and applications) and (hypertextual space in theatrical performance), and the investigations resulted in indicators, including:
1- Hypertext is interacting interactively, but it is organized by correlation as a basic feature that defines it with different manifestations.
2- The hypertext combines the word with other formative elements that reduce a set of tagged information (word, image, light, shadow, color, number).
In the third chapter (research procedures) (Lord play) was
دور اللوبي الصهيوني في صنع السياسة الأمريكية
Drama is one of the means of transmitting human experiences, as it presents within it the life ideas and visions of the spectator, who is subject to their influence on him, robbed of the will in front of its charm and various display arts, which invade him with its dimensions and affect his references, and this art form is based on stories revolving around personalities involved in events that have grown As a result of the struggle of two conflicting opponents, or two opposing forces or emotions generated as a result of a voluntary conflict, as this dramatic conflict represents the most important elements of those events, as it is embodied in an inevitable scene that emerges from other scenes, and this scene is sometimes subject to the
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