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Comparison of root canal transportation and centering after instrumentation through conservative and traditional access cavities using different file systems
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Introduction:

While conservative access preparations could increase fracture resistance of endodontically treated teeth, it may influence the shape of the prepared root canal. The aim of this study was to compare the prepared canal transportation and centering ability after continuous rotation or reciprocation instrumentation in teeth accessed through traditional or conservative endodontic cavities by using cone-beam computed tomography (CBCT).

Materials and Methods:

Forty extracted intact, matured, and 2-rooted human maxillary first premolars were selected for this study. Teeth were equally divided into two groups according to the access cavity design (traditional or conservative). Each group (n = 20) was further subdivided according to instrumentation technique (n = 10) into rotary 2 shape and reciprocation R-motion file subgroups. The teeth were scanned pre and post instrumentation using Planmeca ProMax to obtain two CBCT images for each sample. Images were analyzed and root canal transportation and centering ability were calculated for both buccal and palatal roots at three levels from their apices (3, 5 to 7 mm).

Results:

Although conservative access cavities showed more canal transportation and less centering ability than the traditional one, there was no statistically significant difference (P > 0.05) between them at all levels. Furthermore, no statistically significant difference has been identified in the same parameter between the two instrumentation techniques (continuous rotation and reciprocation) (P > 0.05). However, longer instrumentation time was measured in the conservative group compared to traditional.

Conclusion:

The size of endodontic access cavity has no effect on root canal transportation and centering ability when instrumentation was performed using 2 shape and R-motion file systems.

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Publication Date
Wed Sep 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Free Convection in an Inclined Concentric Annular Square Cavities Filled With Porous Medium and Heated By Non-Uniform Temperature
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A numerical study of the two-dimensional steady free convection flow in an inclined annulus between two concentric square cavities filled with a porous medium is presented in this paper for the case when the side outer walls are kept with differentially heated temperature while the horizontal outer walls and the inner walls are insulated. The heated wall is assumed to have spatial sinusoidal temperature variation about a constant mean value. The Darcy model is used and the fluid is assumed to be a standard Boussinesq fluid. For the Cartesian coordinate system, the governing equations which were used in stream function form are discretized by using the finite difference method with successive under – relaxation method (SUR) and are solv

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Publication Date
Mon May 01 2023
Journal Name
Journal Of Engineering
Evaluation the Western Canal of Al- Ishaqi Irrigation Project
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The water scarcity that Iraq suffers from and the low irrigation efficiency in irrigation projects, therefore, it was necessary to evaluate the performance of the irrigation system of the western canal for the Ishaqi irrigation project in Salah al-Din Governorate to determine the water management strategies that can be used to improve the irrigation efficiency in the project. The performance of the field irrigation system was evaluated on two fields of different crops and irrigation methods according to the agricultural reality of the study area in the Western canal for the Al-Ishaqi Irrigation Project in Salah Al-Din Governorate. The fieldwork included measurements of the moisture content before and after irrigation, fi

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Publication Date
Sun Feb 27 2011
Journal Name
University Of Baghdad
Determination of Cimetidine and Erythromycin ethylsuccinate Drugs Using Different Spectrophotometric Methods (Ph.D. Thesis)
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In this study, four different spectrophotometric methods were applied for determination of cimetidine and erythromycin ethylsuccinate drugs in pure form and in their pharmaceutical preparations. The suggested methods are simple, sensitive, accurate, not time consuming and inexpensive. The results showed the following: The first method: Based on the formation of ion pair complex of each drug with bromothymol blue (BTB) as a chromogenic reagent. The formed complexes were extracted with chloroform and their absorbance values were measured at 427.5 nm for cimetidine and 416.5nm for erythromycin ethylsuccinate; against their reagents blanks. Two different methods, univariate method and multivariate method, were used to obtain the optimum condit

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Publication Date
Sun Dec 29 2019
Journal Name
Iraqi Journal Of Science
Calculating the variations of sunrise, sunset and day length times for Baghdad city.With comparison to different regions of the world in year 2019
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     The sunrise, sunset, and day length times for Baghdad (Latitude =33.34º N, Longitude =44.43º E) were calculated with high accuracy on a daily basis during 2019. The results showed that the earliest time of sunrise in Baghdad was at 4h: 53m from 5 Jun. to 20 Jun while the latest was at 7h: 07m from 5 Jan. to 11 Jan. The earliest time of sunset in Baghdad was at16 h: 55m from 30 Nov. to 10 Dec. whereas the latest was at 19h: 16m from 25 Jun. to 5 Jul. The minimum period of day length in Baghdad was 9h: 57m) in 17 Dec. whereas the maximum period was 14h: 22m) in 20 Jun. Day length was calculated and compared among regions of different latitudes(0, 15, 30, 45 and 60 north).

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Publication Date
Fri Mar 01 2019
Journal Name
Al-khwarizmi Engineering Journal
Comparison of Practical Investigations for CO Emissions Emitted From Single Cylinder S. I. Engine Fueled With Different Kinds of Hydrocarbon Fuels and Hydrogen
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Liquefied petroleum gas (LPG), Natural gas (NG) and hydrogen were all used to operate spark ignition internal combustion engine Ricardo E6. A comparison of CO emissions emitted from each case, with emissions emitted from engine fueled with gasoline as a fuel is conducted.

The study was accomplished when engine operated at HUCR for gasoline n(8:1), was compared with its operation at HUCR for each fuel. Compression ratio, equivalence ratio and spark timing were studied at constant speed 1500 rpm.

CO concentrations were little at lean ratios; it appeared to be effected a little with equivalence ratio in this side, at rich side its values became higher, and it appeared to be effected by equivalence ratio highly, the results s

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Publication Date
Sun Mar 07 2010
Journal Name
Baghdad Science Journal
The Direct Gene Injection Using of Egg Yolk Emulsion as Carrier and its Comparison with Liposomes.
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The efficiency of egg yolk emulsion in coating DNA and its delivery across cellular membranes was evaluated in comparison with liposomes DOPE . The murine leukemia viral oncogene v-abl , cloned on pBR322 was used as a DNA substrate for direct injection into mice tissue . the DNA complexes were prepared by mixing the DNA with egg yolk emulsion and liposome . Each was directly injected into mice peritoneal cavity with proper control. The gene delivery was examined phenotypically by blood analysis and cytogenetic analysis . Chromosomal changes were detected in the bone marrow as from the fourth day post inoculation through the eleventh day when chromosomal ring s could be seen . this was accompanied by decrease in the WBC count ,

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Publication Date
Sat Dec 31 2022
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of Robust Circular S and Circular Least Squares Estimators for Circular Regression Model using Simulation
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In this paper, the Monte-Carlo simulation method was used to compare the robust circular S estimator with the circular Least squares method in the case of no outlier data and in the case of the presence of an outlier in the data through two trends, the first is contaminant with high inflection points that represents contaminant in the circular independent variable, and the second the contaminant in the vertical variable that represents the circular dependent variable using three comparison criteria, the median standard error (Median SE), the median of the mean squares of error (Median MSE), and the median of the mean cosines of the circular residuals (Median A(k)). It was concluded that the method of least squares is better than the

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Publication Date
Thu Oct 18 2018
Journal Name
European Journal Of Organic Chemistry
PdII-Mediated Oxidative Amination for Access to a 9-Azabicyclo[4.2.1]nonane Compound Library and Anatoxin-a
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Publication Date
Thu Jun 16 2022
Journal Name
Periodicals Of Engineering And Natural Sciences (pen)
Optimization algorithms for transportation problems with stochastic demand
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The purpose of this paper is to solve the stochastic demand for the unbalanced transport problem using heuristic algorithms to obtain the optimum solution, by minimizing the costs of transporting the gasoline product for the Oil Products Distribution Company of the Iraqi Ministry of Oil. The most important conclusions that were reached are the results prove the possibility of solving the random transportation problem when the demand is uncertain by the stochastic programming model. The most obvious finding to emerge from this work is that the genetic algorithm was able to address the problems of unbalanced transport, And the possibility of applying the model approved by the oil products distribution company in the Iraqi Ministry of Oil to m

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Publication Date
Sun Sep 05 2010
Journal Name
Baghdad Science Journal
Design and Testing a Neutrons and Gamma-Rays Multilayer Shield Using Different Groups of Cross – Sections
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A preventing shield for neutrons and gamma rays was designed using alternate layers of water and iron with pre-fixed dimensions in order to study the possibility of attenuating both neutrons and gamma-rays. ANISN CODE was prepared and adapted for the shield calculation using radiation doses calculation: Two groups of cross-section were used for each of neutrons and gamma-rays that rely on the one – dimensional transport equation using discrete ordinate's method, and through transforming cross-section values to values that are independent on the number of groups. The memory size required for the applied code was reduced and the results obtained were in agreement with those of standard acceptable document samples of cross –section, this a

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