Background: The aim of this study was to evaluate the push-out bond strength of four different obturation materials to intraradicular dentin and to determine the failure mode. Materials and method: forty straight palatal roots of the maxillary first molars teeth were used in this study, the roots were instrumented using crown down technique and rotary EndoSequence system, the roots were randomly divided into four groups according to the materials used for obturation (n=10).Group (1): AH Plus sealer and gutta-percha. Group (2): Activ GP glass ionomer sealer and Activ GP gutta-percha (Activ GP system). Group (3): Bioceramic sealer and Bioceramic gutta-percha. Group (4): GuttaFlow2 sealer and gutta-percha. For all groups single cone obturation technique was used. After incubation period of one week, the roots were embedded in clear acrylic resin and each root sectioned into three levels apical, middle and cervical. The bond strength was measured using computerized universal testing machine, each section fixed in the machine so that the load applied from apical to coronal direction at 0.5mm/min speed and the computer drew curve to show the higher bond force before dislodgment of the filling material. After de-bonding each sample was examined under Stereomicroscopic and the type of failure mode was recorded. Results: showed a non significant difference between AH plus group and Bioceramic group. AH Plus group showed a very highly significant difference with Activ GP group and a highly significant difference with GuttaFlow2 group. There were significant differences between coronal level and both apical and middle levels with no significant differences between apical and middle levels within each group. Conclusion: AH plus group showed the highest mean of bond strength in comparing to other tested groups
This study was conducted on species composition, morphology, ecological characteristics, biotope distribution, ecological groups, biodiversity indicators and zoogeography of leeches and gastropods distributed in the lower Ak-Buura River. According to the results, it was found that 7 species of leeches belonging to 4 families and 6 genera and 10 species of fresh-water gastropods belonging to 3 families and 6 genera live in the lower Ak-Buura River. In the river, it was observed that leeches are mainly distributed in muddy biotopes, and gastropods are widespread in muddy, stony and sandy biotopes with a lot of plants. Biodiversity indices of leeches and gastropods in the Ak-Buura River were analyzed using the Shannon index. As a result, it
... Show MoreIn this research, we attempt to show the extent of harmony in an aspect of the text according to the stylistics for the Knowing of the stylistic value of the title threshold, and the pathways of titles that suggest and support the meaning when the recipient reads the literary text, in addition to the interpretations that reflect the purposes of the poet who contributed to the drawing of his poetic achievement. The research presented a brief about the poet and his most important works, because they are the text which will be studied according to the stylistics. The research also explained the concept of style and the stylistics in the preface , because of the stylistic is the method adopted by the research to study the title thresholds in
... Show MoreThis research focuses on the field of theatrical production, and focuses on the semantic displacement of the sign in the visual formation of the theater show, so the research has been entitled: "The semantic displacement of the sign and the visual formation of the postmodern theater ". Its importance is to illustrate the aesthetics produced by the semantic displacement of the theatrical sign and it is specialized in postmodern theater. The purpose of the research can be delimited to revealing the aesthetic work of the semantic displacement of the sign and the visual formation in the postmodern theatre. The study temporal boundary is 2017 and the capital of Baghdad is its spatial boundaries. The research sample was "Striptease
... Show MoreEach school of Islamic jurisprudence has principles and rules upon which the diligent work in these schools is based. This is due to the view of sanctification of these rulings, as they are divine rulings. Therefore, the goal is to reach a ruling that represents the intent of the legislator as much as possible.
Hence, these schools of thought established rules for issuing fatwas with the intention of restricting the performance of a fatwa to the hands of those who are qualified for it and have met its conditions, so they gave priority to the most knowledgeable person over others to perform the fatwa. In the Hanafi school of thought, for example, the saying of Imam Abu Hanifa (may God have mercy on him) is given precedence over others,
This research is a result of other studies made about the iraqi public and its relationship with different states institutions, until recently, such studies were almost non-existent. The main characteristic that distinguishes scientific research is that it involves a specific problem that needs to be studied and analysed from multiple aspects. What is meant by identifying the problem, is to limit the topic to what the researcher wants to deal with, rather than what the title suggests as topics which the researcher doesn’t want to deal with. The problem of this research is the absence of thoughtful and planned scientific programs to build a positive mental image of the institutions of the modern state in general and the House of Represe
... Show MoreThis study was aimed to reduce the amount of the sprayed solution lost during trees spraying. At the same time, the concentration of the sprayed solution on the target (tree or bush) must be ensured and to find the best combination of treatments. Two factors controls the spraying process: (i) spraying speed (1.2 km/h, 2.4 km/h, 3.6 km/h), and (ii) the type of sensor. The test results showed a significant loss reduction percentage. It reached (6.05%, 5.39% and 2.05%) at the speed (1.2 km/h, 2.4 km/h, 3.6 km/h), respectively. It was noticed that when the speed becomes higher the loss becomes less accordingly. The interaction between the 3.6 km/h speed and the type of Ultrasonic sensor led to a decrease in the percentage of the spray
... Show MoreThe novel groups of organic chromophores containing triphenylamine (TPA) (ATP-I to ATP-IV) have been constructed by structural modification of electron donors with substitution biphenyl and bipyridine rings inserting a π-linkage. Density functional theory (DFT) and time-dependent type of it (TD-DFT) have been operated to study results of donating ability of TPA and spacer on absorption, geometrical, photovoltaic, and energetic attributes of these sensitizers. Structural attributes have been revealed that incorporation of TPA, acceptor and π bridge include a perfect coplanar conformation in TPA-III. Based on frequency computations and ground-state optimization, bandgap (Eg) energy, ELUMO, EHOMO have been determined. For enlightening maximu
... Show MoreThis research set out to provide a faster, easier, and more efficient process for nanoparticle (NP) synthesis of aluminum oxide NPs preparation by microwave irradiation, using plant extracts separately and in the same way (tea, coffee, rosemary), which is an easy-to-use and inexpensive method. The structural properties were investigated by X-ray diffractometer analysis technique (XRD). The X-ray analysis shows the structure has a polycrystalline nature with a hexagonal phase. The optical properties were studied using ultraviolet visible (UV-Vis) spectrometer, where the energy gap was determined. The surface morphology properties of the prepared aluminum NPs were examined by atomic force microscope (AFM). The Fourier transform infra
... Show MoreIn this research the effect of cooling rate and mold type on mechanical properties of the eutectic
and hypoeutectic (Al-Si) alloys has been studied. The alloys used in this research work were (Al- 12.6%Si
alloy) and (Al- 7%Si alloy).The two alloys have been melted and poured in two types of molds with
different cooling rates. One of them was a sand mold and the other was metal mold. Mechanical tests
(hardness, tensile test and impact test) were carried out on the specimens. Also the metallographic
examination was performed.
It has been found that the values of hardness for the alloys(Al-12.6%Si and Al-7%Si) which poured in
metal mold is greater than the values of hardness for the same alloy when it poured in a heated