Background: The main aim of the present study is to qualify and quantify voids formation of root canals obturated with GuttaCore (GC) and experimental Hydroxyapatite polyethylene (HA/PE) as new carrier-based root canal fillings by using micro computed tomography scan. Materials and methods: In the present study, eight straight single-rooted human permanent premolar teeth are selected and disinfected, then stored in distilled water. The teeth decoronated leaving a root length of 12mm each. The root canals instrumented by using crown down technique and the apical diameter of the root canal prepared to a size # 30/0.04 for achieving standardized measurements. A 5mL of 17% EDTA used to remove the smear layer followed by 5mL of 2.5% NaOCl and rinsing with normal saline. Then the shaped root canals were randomly subdivided into two groups of 4 teeth each according to the carrier-based obturation system use, GuttaCore or experimental HA/PE. Afterwards, the obturated roots stored at 37°C with 100% humidity for 72 hours to allow for complete setting of the sealer. Micro-CT was then scanned to quantify the voids within the root canal space. The data were statistically analyzed by one-way ANOVA and post hoc comparison tests (α=0.05). Results: The root canals obturated with both obturation systems, GuttaCore andexperimental HA/PE showed voids formation, particularly at the apical third of the root canal. GC obturation showed a lower percentage of voids volume (1.54%) than the experimental HA/PE obturation (2.3%). The void volume percentage in the GuttaCore system, however, was non-significantly different (P> 0.05) in comparison with the experimental PE/HA system. Conclusions: GuttaCore and experimental HA/PE obturators exhibited voids formation within the entire root canal space. The experimental HA/PE obturator is comparable to the GuttaCore obturator in terms of voids qualification
The technology and modern social communication medias have contributed to changing many of our concepts about education to a large extent; these technological advancements have created new challenges for the Instructor of course, but on the other hand it did provided him with expressive media, models and strategies that the old methods cannot fulfill, including the flipped classroom strategy, which is one of the modern technical solutions and in it's optimal use it can correct the weakness of the traditional education and can develop the communication skills as a whole among the students, in order to create a positive, active and interactive student.
The current research contained - four chapters: the first one included the methodolog
The current research aims to analyze the extent of the adoption of the standards of ISO 45001: 2018 for occupational safety and health management by the General Establishment of Civil Aviation. The research problem was the extent to which the General Establishment of Civil Aviation approved ISO 45001: 2018 for occupational safety and health management. The questionnaire was used as a primary data collection tool, the sample was distributed (50) form, they were selected from the category of employees of the establishment at different levels to represent the research community. Data were analyzed using the statistical package (SPSS), a number of vector statistical methods were used as well as arithmetic mean, standard deviation, an
... Show MoreThe results show the inability to apply the Taylor rule within inflation and GDP Gaps because the monetary behave is elated from the Iraqi economy.
When applying the Taylor rule to exchange rate with the inflation and the output gap, the results do not match the nominal price announced by the central thing, which proves the lack of commitment by the Central Bank by using the Taylor rule, whether short-run interest rate or exchange rate (Nominal Anchor), so it did not stay to the Iraqi Central Bank only using the principle of Taylor with the expected inflation rate below the level of output (Macro activity) for the separation of monetary behavior from the real one o
... Show MoreThe easternmost extent of the Pharaoh Eagle Owl Bubo ascalaphus (Savigny, 1809)
distribution has remained enigmatic due to id entification problems and lack of owl research.
In Iraq, B. ascalaphus has been reported from only few localities in western Iraqi deserts;
while its occurrence in Iran has not been reported before this study. In 2017 2020, several
new records of B. ascala phus in western through southeastern Iraq were made and a new
distribution range in western Iran was confirmed. Furthermore, field identification,
interspecific relationships and conservation status of B. ascalaphus in Iraq and Iran were
comprehensively di scussed.
Polymer metal complexes of poly ethylene glycol acetal and Ag (I), Cu (II), Ni (II), Mn (II), Co (III) and Hg (II) were prepared from the reaction of PEG with aldehyde derived fromErythro-ascorbic acid (pentulosono-ɣ-lactone-2, 3- enedianisoate). All these compounds were characterized by Thin Layer Chromatography (TLC) and FTIR spectra and aldehyde was also characterized by (U.V-Vis), 1HNMR,13CNMR, and mass spectra. It has been established that, the polymer and its metal complexes showedgood activities against four pathogenic bacteria (Escherichia coli , Klebsiellapneumonae,Staphylococcusaureus, Staphylococcus Albus) and two fungal (Aspergillus Niger,Yeast). The polymer metal complexes showed higher activity than the free polymer.Theorder
... Show MoreMany researchers consider Homogeneous Charge Compression Ignition (HCCI) engine mode as a promising alternative to combustion in Spark Ignition and Compression Ignition Engines. The HCCI engine runs on lean mixtures of fuel and air, and the combustion is produced from the fuel autoignition instead of ignited by a spark. This combustion mode was investigated in this paper. A variable compression ratio, spark ignition engine type TD110 was used in the experiments. The tested fuel was Iraqi conventional gasoline (ON=82).
The results showed that HCCI engine can run in very lean equivalence ratios. The brake specific fuel consumption was reduced about 28% compared with a spark ignition engine. The experimental tests showed that the em
... Show MoreABSTRACT
Impkact of Knowledge sharing on organizational innovation Impriscal study in Arabic company .
of Knowledge Management is the main component Knowledge sharing system, it mean the exchange if Knowledge, ideas, and good practice with another individual . Knowledge sharing between persons, then its values can growth .
It is vry important because it can provide us with the contention between virus peoples . the interaction among the people can pass all kind of Knowledge among them. the connection and interaction and interaction enabl
... Show MoreThis paper studied the behaviour of reinforced reactive powder concrete (RPC) two-way slabs under static load. The experimental program included testing three simply supported slabs of 1000 mm length, 1000 mm width, and 70 mm thickness. Tested specimens were of identical properties except their steel fibers volume ratio (0.5 %, 1 %, and 1.5 %). Static test results revealed that, increasing steel fibers volume ratio from 0.5% to 1% and from 1% to 1.5%, led to an increase in: first crack load by (32.2 % and 52.3 %), ultimate load by (36.1 % and 17.0 %), ultimate deflection by (33.6 % and 3.4 %), absorbed energy by (128 % and 20.2 %), and the ultimate strain by (1.1 % and 6.73 %). The stiffness and ductility of the specimens also increased. A
... Show More