Forty lower premolars with single root canals prepared with ProtaperNext files to size 25, and obturated with GP/sealer using lateral compaction. Teeth divided randomly into four groups (group n=10). Protaper universal retreatment kit (PUR), D-Race desobturation files (DRD), R-Endo retreatment kit (RE) and Hedstrom (H) files (control) were used to remove GP/sealer in each group. Removal effectiveness assessed by measuring the GP /sealer remnants in the roots after sectioning them into two halves. Stereomicroscope with a digital camera used to capture digital images. Images processed by ImageJ software to measure the percentage of GP/sealer remnants surface area in total, coronal, middle and apical areas of the canal. In the coronal area, PUR had significantly lower R% than RE and H groups, respectively (p<0.05). Also, DRD had significantly lower R% than RE (P<0.05). There was no significant difference between PUR and DRD (p>0.05), as well as no significant difference between RE and H groups(p>0.05). In the middle, apical and total root areas, Both PUR and DRD had significantly lower R% than RE and H groups, respectively (p<0.05). There was no significant difference between PUR and DRD (p>0.05). Also, there was no significant difference in R% between RE and H groups (p>0.05).
This study deals with the elimination of methyl orange (MO) from an aqueous solution by utilizing the 3D electroFenton process in a batch reactor with an anode of porous graphite and a cathode of copper foam in the presence of granular activated carbon (GAC) as a third pole, besides, employing response surface methodology (RSM) in combination with Box-Behnk Design (BBD) for studying the effects of operational conditions, such as current density (3–8 mA/cm2), electrolysis time (10–20 min), and the amount of GAC (1–3 g) on the removal efficiency beside to their interaction. The model was veiled since the value of R2 was high (>0.98) and the current density had the greatest influence on the response. The best removal efficiency (MO Re%)
... Show MoreThe biosorption of lead (II) and chromium (III) onto dead anaerobic biomass (DAB) in single and binary systems has been studied using fixed bed adsorber. A general rate multi- component model (GRM) has been utilized to predict the fixed bed breakthrough curves for single and dual- component system. This model considers both external and internal mass transfer resistances as well as axial dispersion with non-liner multi-component isotherm (Langmuir model). The effects of important parameters, such as flow rate, initial concentration and bed height on the behavior of breakthrough curves have been studied. The equilibrium isotherm model parameters such as maximum uptake capacities for lead (II) and chromium (III) were found to be 35.12 and
... Show MoreSeveral recent approaches focused on the developing of traditional systems to measure the costs to meet the new environmental requirements, including Attributes Based Costing (ABCII). It is method of accounting is based on measuring the costs according to the Attributes that the product is designed on this basis and according to achievement levels of all the Attribute of the product attributes. This research provides the knowledge foundations of this approach and its role in the market-oriented compared to the Activity based costing as shown in steps to be followed to apply for this Approach. The research problem in the attempt to reach the most accurate Approach in the measurement of the cost of products from th
... Show MoreThe present work aims to study forward osmosis process using different kinds of draw solutions and membranes. Three types of draw solutions (sodium chloride, sodium formate, and sodium acetate) were used in forward osmosis process to evaluate their effectiveness with respect to water flux and reverse salt flux. Experiments conducted in a laboratory-scale forward osmosis (FO) unit in cross flow flat sheet membrane cell. Three types of membranes (Thin film composite (TFC), Cellulose acetate (CA), and Cellulose triacetate (CTA)) were used to determine the water flux under osmotic pressure as a driving force. The effect of temperature, draw solution concentration, feed and draw solution flow rate, and membrane types, were studied with
... Show MoreFinancial crisis is one of the topics that have attracted the interest of researchers in recently. The research focused on the issue of the crisis of the Asian Tigers and the mortgage crisis and comparing them in terms of causes and repercussions. It may meet most of the financial crises in many of its causes, factors, roots and results in the advanced and the developing countries. This crisis has its own pattern and its causes and nature and it is characterized by a crisis of cash liquidity and the collapse of many banks and declare bankruptcy and a sharp decline in stock prices and indices of the stock market and so far the common denominators among the causes but does not mean this There are differences between the financial c
... Show MoreLinguistic research according to modern curricula:
It is one of the important matters that occupy the ideas of those concerned with linguistic studies, whether Arabic or otherwise. Recent years have witnessed the advancement of this methodological approach, and books and studies in Arabic have been written on important, multifaceted issues, of grammatical and linguistic origins, and their balance with new developments and ideas attracted mostly from Western studies.
The comparative approach - as they call it - is one of the modern approaches that is based on balancing a language with other sisters belonging to its family, to reach similarities and differences between them, and to know the c
In this paper, two types of iron oxide nanomaterial (Fe3O4) and nanocomposite (T-Fe3O4) were created from the bio-waste mass of tangerine peel. These two materials were utilized for adsorption tests to remove cefixime (CFX) from an aqueous solution. Before the adsorption application, both adsorbents have been characterized by various characterizations such as XRD, FTIR, VSM, TEM, and FESEM. The mesoporous nano-crystalline structure of Fe3O4 and T-Fe3O4 nanocomposite with less than 100-nm diameter is confirmed. The adsorption of the obtained adsorbents was evaluated for CFX removal by adjusting several operation parameters to optimize the removal. The optimal conditions for CFX removal were found to be an initial concentration of 40 and 50 m
... Show MoreOxazine and quinazoline has a very important in organic chemistry especially in hetero cyclic fields. this research consist the preparation of 4H,4'H-2,2'-bibenzo[d][1,3]oxazine-4,4'-dione compound (1) from di acid chloride with 2-aminobenzoic acid in pyridine as solvent to give compound (2) 3,3'-diamino-2,2'- biquinazoline-4,4'(3H,3'H)-dione .compound 2 include free amino group .this compound was reacted with maleic and phthalic anhydride for synthesized of cyclic imide compounds (3,4).another reaction for compound 2 with some substituted aromatic aldehyde for prepared of some novel Schiff bases (5-9) contains quinazoline ring. compound 1 was treated with sulfathiazole and sulfadiazine for synthesized of sulfa compounds contains sulf
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