Background: The bond strength of endodontic sealers with dentin is a very important property for maintaining the integrity and seal of the root canal filling. The aim of this study was to evaluate and compare the effect of various irrigants (QMix, 17% EDTA and 2.5% NaOCl) on the push-out bond strength of AH plus and Bioceramic sealers. Materials and methods: Forty eight freshly extracted maxillary first molars human teeth with striaght palatal root were used in the study. The collected samples were randomly divided into three groups of equal sample size (n=16), according to the final irrigation regimen as follows: Group (1): QMix 2 in 1, Group (2): 17% ethylenediaminetetraacetic acid, Group (3): 2.5% sodium hypochloride. All samples were instrumented using Edge file X7 rotary instrument reaching file size 40/.04 as the final master apical file. After that each group was randomly divided into two subgroups (n=8) according to the type of sealer used: AH Plus and Total Fill BC Sealer. Obturation was conducted using single cone technique with gutta percha (GP) to all experimental roots. Two-millimeter thick slices were obtained from the middle section of the root. Bond strength of sealers was measured via a universal testing machine by using stainless steel plunger. Then, the data were statistically evaluated using two-way analysis of variance (ANOVA) and post hoc test (Bonferroni’s test). Results: The push-out bond strength was significantly increased by the “irrigant†factor (P≤0.05) and by “sealer/irrigation solution†interaction (P≤0.05). Final rinse with QMix solution with BC sealer showed the highest mean value of bond strength (5.976 MPa), with a significant difference with other groups (P≤0.05), while NaOCl with AH Plus sealer showed the lowest mean value of bond strength (3.811 MPa). Conclusion: Final irrigation of the root canals with different irrigants improved the endodontic sealer's bond strength, and QMix had a positive influence on the adhesion of BC sealer.
This paper presents a computer simulation model of a thermally activated roof (TAR) to cool a room using cool water from a wet cooling tower. Modeling was achieved using a simplified 1-D resistance-capacitance thermal network (RC model) for an infinite slab. Heat transfer from the cooling pipe network was treated as 2-D heat flow. Only a limited number of nodes were required to obtain reliable results. The use of 6th order RC-thermal model produced a set of ordinary differential equations that were solved using MATLAB - R2012a. The computer program was written to cover all possible initial conditions, material properties, TAR system geometry and hourly solar radiation. The cool water supply was considered time
... Show MoreA study of non-diatom algal species composition in twelve sites from Greater Zab River path within
Erbil Province, was carried out from April 2021 to January 2022 with monthly sample collection in twelve studied sites. Among them site 4,5,6,7 and 9 are the first for algal study in this area. The 112 different species of algae belong to 33 genera, 25 families, 13 orders and 4 divisions have been identified. The predominant genera included Spirogyra and Cosmarium 17, 8 taxa respectively. 13 taxa were new recorded to Iraqi
Kurdistan algal flora and 9 of them were new recorded to Iraqi algal flora: Botryosphaerella sudetica, Muriella magna, Gloeotaenium loitlesbergianum, Apiocystis brauniana, Anabaena oscillarioides, C. distentum
Semiconductor-based photocatalytic processes are widely applied as ecofriendly technology for degrading organic pollutants. Establishing photocatalytic heterojunctions with Z-type photocarriers transfer pathways is projected to be a superb strategy to enhance photocatalytic behavior. In this paper, novel and stable (0D/2D) heterojunctions of CoS-embedded boron-doped g-C3N4 (CoS/BCN) with a high rate of charges transfer/separation were assembled for degradation of malachite green dye (MG). The CoS/BCN photocatalyst achieves a photodegradation efficiency of 96.9 % within 1 h of LED illumination, which is 2.5 and 1.4-fold enhancement compared with bare g-C3N4 and BCN, respectively. Besides, the results of species-trapping trials exhibited that
... Show MoreErratum for Organic acid concentration thresholds for ageing of carbonate minerals: Implications for CO2 trapping/storage.
Abstract
This Research aims for harnessing critical and innovative thinking approaches besides innovative problem solving tools in pursuing continual quality improvement initiatives for the benefit of achieving operations results effectively in water treatment plants in Baghdad Water Authority. Case study has been used in fulfilling this research in the sadr city water treatment plant, which was chosen as a study sample as it facilitates describing and analyzing its current operational situation, collecting and analyzing its own data, in order to get its own desired improvement opportunity be done. Many statistical means and visual thinking promoting methods has been used to fulfill research task.
... Show MoreBackground: Ultrasonography has been used to examine the thickness of the lower uterine segment in women with previous cesarean sections in an attempt to predict the risk of scar dehiscence during subsequent pregnancy. The predictive value of such measurement has not been adequately assessed. Objectives: To correlate lower uterine segment thickness measured by trans abdominal ultrasound in pregnant women with previous cesarean section with that measured during cesarean section by caliper and to find out minimum lower uterine segment thickness indicative of integrity of the scar.Methods: A prospective observational study at Elwyia Maternity Teaching Hospital, from January 2011 to January 2012. A total of 143 women were enrolled in the stu
... Show MoreThe research amid to find out the extent of Iraqi oil companies commitment to implement internal control procedures in accordance with the updated COSO framework. As the research problem was represented in the fact that many of the internal control procedures applied in the Iraqi oil companies are incompatible with most modern international frameworks for internal control, including the integrated COSO framework, issued by the Committee of Sponsoring Organizations of the Tradeway Committee. The research followed the quantitative approach to handling and analysing data by designing a checklist to represent the research tool for collecting data. The study population was represented in the Iraqi oil companies, while the study sample
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