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.
Nanocrystalline aluminophosphate AlPO4-5 molecular sieves were synthesized by hydrothermal method (HTS). Synthesis parameters like time and temperature of crystallization were investigated. Type of template (R) and ratio of R/P2O5 were studied also. Characterization of the synthesized AlPO4-5 were done by powder X-ray diffraction (XRD), scanning electron microscopy (SEM/EDX), Fourier transform infrared (FTIR), differential scanning calorimetry-thermogravimetry analysis (DSC-TGA), and N2 adsorption-desorption BET analysis. XRD patterns results showed excellent crystallinity for two types of templates, di-n-propylamine (DPA) and tetrapropyl ammonium hydroxide (TPAOH) f
... Show MoreThis semiotic analytical study has shown that there is a wide diversity in the aesthetic systems and the ranges of reception for the rhetoric and the discourse. The fertility of this semiotic conceptual system monitored this new mature, innovative and advanced level of this new critical analytical method with its different technical and theoretical foundations. Thus, it opened the door wide to new discoveries in the laws, which motivate different artistic texts. Finally, the research is just a start. Can the linguistic methods read the artistic works outside the linguistic authorities? Is it possible to capture the structural transformation in Picasso drawings? Semiotically another researcher in another method (such as deconstruction) ca
... Show MoreRecent decades have witnessed tremendous economic development that has led to the spread of international companies (multinational companies) and its activity has expanded to cover many countries of the world, with intense competition among countries to attract more international investments, which has led to the emergence of some controversial accounting issues in many Relevant areas, including accounting for transactions in foreign currencies, translation of financial statements for companies and foreign branches, as this issue is an important and sensitive topic because many of its aspects are controversial and not yet resolved, especially with regard to the variation in standards and Relevant accounting practices from one country to
... Show MoreThis paper is devoted to introduce weak and strong forms of fibrewise fuzzy ω-topological spaces, namely the fibrewise fuzzy -ω-topological spaces, weakly fibrewise fuzzy -ω-topological spaces and strongly fibrewise fuzzy -ω- topological spaces. Also, Several characterizations and properties of this class are also given as well. Finally, we focused on studying the relationship between weakly fibrewise fuzzy -ω-topological spaces and strongly fibrewise fuzzy -ω-topological spaces.
Salbutamol sulphate nebules is considered as the most rapid effective route of
administration for treatment of acute attacks of asthma .
This study was carried out to formulate a stable formula of salbutamol nebules
containing 0.1% (2.5mg / 2.5ml) of the active ingredient in a buffered solution .
Stability study in different buffers at pH 3 showed that the longest shelf life was
equal to 3.5 years for formula F .In addition the bioequivalency of this formula
incomparison to ventolin® nebules was measured and it was equal to (± 5.2) %.
Also it was found that there was no significant difference between the formula
and ventolin® nebules regarding their pharmacokinetic parameters which include
elimination
Abstract
This paper represents a study of the effect of the soil type, the drilling parameters and the drilling tool properties on the dynamic vibrational behavior of the drilling rig and its assessment in the drilling system. So first, an experimental drilling rig was designed and constructed to embrace the numerical work.
The experimental work included implementation of the drill-string in different types of soil with different properties according to the difference in the grains size, at different rotational speeds (RPM), and different weights on bit (WOB) (Thrust force), in a way that allows establishing the charts that correlate the vibration acceleration, the rate of penetration (ROP), and the power
... Show MoreThe aim of this research is to know danger of radioactive isotopes
that are found in samples of drugs traded in Iraqi markets. The
samples are Iraqi Amoxicillin, English Amoxicillin, UAE
Amoxicillin, Indian Amoxicillin, Iraqi Paracetamol, English
Paracetamol, UAE Paracetamol and Indian Paracetamol. By high
purity germanium the activity of the following isotopes 40K, 214Pb,
228Ac and 137Cs is measured and the specific activity was used to
calculate the annual effective dose. Then the calculated annual
effective dose values are compared with the allowable annual
effective dose values of each part of digestive channel. This research
concluded that the measured annual effective dose values are not
dangerous.<
esearch Summary
Holidays and occasions in Islamic societies have a legal character and origin. Some of them are proven by the words and actions of the legislator, and some are within the scope of custom that is regulated by the honorable Sharia, and others are approved by scholars and people because of their connection, piety and charity. It has a kind of good.
One of the purposes of the noble Sharia is to glorify the honorable times associated with the blessed events, so that lessons and lessons may be recalled in them, and to activate the legitimate gifts in those events that develop in the individual, the family and the community the meanings of goodness and honor and all that is good and good. Accord
... Show MoreCreep testing is an important part of the characterization of composite materials. It is crucial to determine long-term deflection levels and time-to-failure for these advanced materials. The work is carried out to investigate creep behavior on isotropic composite columns. Isotropy property was obtained by making a new type of composite made from a paste of particles of carbon fibers mixed with epoxy resin and E-glass particles mixed with epoxy resin. This type of manufacturing process can be called the compression mold composite or the squeeze mold composite. Experimental work was carried out with changing the fiber concentration (30, 40 and 50% mass fraction), cross section shape, and type of composite. The creep results showed that th
... Show MoreThis article discusses a discussion of trends and patterns of understanding and application of the concept of metaphor to various subjects that may interfere with the perspective of metaphors in translation theory, an attempt was made to use the principles and characteristics of metaphors and their fundamental tradition in translation theory, and to uncover the perspective of considering metaphor as a conceptual process. presenting its merits, since it is still considered an eccentric expression of linguistics.