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.
Objectives: To assess levels of premenstrual psychological disorders of the students in Bab Al-Mua’dham Complex and to find out the relationship between the levels of premenstrual psychological and physical disorders and some demographic characteristics of the students. Methodology: A descriptive study was accomplished throughout the period from the 1st of October, 2015 to the 8th of July, 2016 to assess the psychological and physical problems. A purposive sample of 313 students distributed among different colleges of Bab Al-Mua’dam complex distributed as following: 82 students are from college of Arts; 79 students are from College of Languages; 48 students are from college of Islamic Sciences: and 104 are from College of Nursing. For t
... Show More
(2)
Compression for color image is now necessary for transmission and storage in the data bases since the color gives a pleasing nature and natural for any object, so three composite techniques based color image compression is implemented to achieve image with high compression, no loss in original image, better performance and good image quality. These techniques are composite stationary wavelet technique (S), composite wavelet technique (W) and composite multi-wavelet technique (M). For the high energy sub-band of the 3 rd level of each composite transform in each composite technique, the compression parameters are calculated. The best composite transform among the 27 types is the three levels of multi-wavelet transform (MMM) in M technique wh
... Show MoreAutonomous motion planning is important area of robotics research. This type of planning relieves human operator from tedious job of motion planning. This reduces the possibility of human error and increase efficiency of whole process.
This research presents a new algorithm to plan path for autonomous mobile robot based on image processing techniques by using wireless camera that provides the desired image for the unknown environment . The proposed algorithm is applied on this image to obtain a optimal path for the robot. It is based on the observation and analysis of the obstacles that lying in the straight path between the start and the goal point by detecting these obstacles, analyzing and studying their shapes, positions and
... Show MoreIn pre- Islamic poetry, there are a lot of words that indicate
peacefulness of one sort of another, in addition to the inspirations of semantic
modeling in which the poet sets himself in various horizons.
Among these words: brother, comrade, friend, companion, lover,
people, prince, home, land, country, blessing, honesty, contract, company,
justice, thankfulness, forgiveness, pardoning, guest, goodness, faithfulness,
silence, death, peace,….
In addition, there are their derivatives from various aspects that indicate
peacefulness either directly or indirectly.
يهدف البحث إلى دراسة التحفظات على اتفاقية سيداو (الدول العربية أنموذجًا)، حيث يُعد نظام التحفظ على الاتفاقيات الدولية أحد المظاهر القانونية الحديثة في مجال العلاقات الدولية، والذي يقرّ بحق الدول في إبداء التحفظ على بعض أحكام الاتفاقيات الدولية، وفقًا للأحكام العامة التي حددتها المواد (19-23) من اتفاقية فيينا لقانون المعاهدات لعام 1969. وإذا كان حق الدول في التحفظ مكفولًا دوليًا، فإن الإشكالية القانونية تكمن في
... Show MoreResearch revealed the most important things:
1 - that the sentence if the nominal manufacturing according to one of the main frames for the construction of the original sentence or the nucleus called the obstetric and called the nominal or actual.
2 - is not an element of denial. Some of them counted in the Acts the people of Basra are missing and some of them are counted conjunction Menem people of Kufa and promise of the tools of the exception and some of them promise to benefit neglected exile is not Flaaml have at this team.
- What precluding it have a characteristic which they enter the actual sentence and never let an impact on the act, and the intervention of the nominal sentence Fathol
أدوات الىفي الذاخلة على الجملة التحويلية الاسمي