Background: The purpose of this study was to evaluate and compare centering ability and canal transportation of simulated S-shaped canals instrumented with four different types of rotary nickel-titanium systems. Materials and Methods: Forty simulated S-shaped canals in resin blocks were divided into four groups of ten each and were instrumented to an apical size 25 by different instrumentation technique using ProTaper Universal files (group A), ProTaperNext (group B), Reciproc (group C) and WaveOne (group D).Centering ability and canal transportation was measured at (11) measuring points from D0 to D10 bysuperimposion of the pre- and post-operative images obtained by using digital camera in standardized manner. An assessment of the canals shape was determined using Photoshop CS2 and AutoCAD software. The data were analyzed statistically using ANOVA and LSD test. Results: In terms of centering ratio values, there was no statistically significant difference among the four groups at the coronal portion of the canals, with ProTaper system showing the least centering ability at all levels except at apical foramen. At the apical curvature, the Reciproc and WaveOne groups showed better centering ability than ProTaperNext and the difference was statistically highly significant among them at these points, while at the coronal curvature the ProTaperNext showed better centering ability than Reciproc and WaveOne. Canal transportation was seen in all groups but the ProTaper systems showed more transportation values at almost levels when compared with the other groups with the least values by ProTaperNext at the coronal curvature and the least values by Reciproc and WaveOne at the apical curvature. Conclusions: Under the conditions of this study, ProtaperNext ,WaveOne and Reciproc instruments maintained the original curvature significantly better than ProTaperUniversal at almost levels. ProtaperNext showed a better shaping ability than Reciproc and WaveOne at the coronal curved section while at apical curved section Reciproc and WaveOne showed a better shaping ability than ProtaperNext. Key words: centering ability, canal transportation, ProTaperNext, Reciproc, WaveOne.
This paper describes the application of consensus optimization for Wireless Sensor Network (WSN) system. Consensus algorithm is usually conducted within a certain number of iterations for a given graph topology. Nevertheless, the best Number of Iterations (NOI) to reach consensus is varied in accordance with any change in number of nodes or other parameters of . graph topology. As a result, a time consuming trial and error procedure will necessary be applied
to obtain best NOI. The implementation of an intellig ent optimization can effectively help to get the optimal NOI. The performance of the consensus algorithm has considerably been improved by the inclusion of Particle Swarm Optimization (PSO). As a case s
Abstract Background Hemoglobin A1c (HbA1c) is a widely used test for glycemic control. It is done for chronic kidney disease (CKD) patients. Renal disease is accompanied by thyroid abnormalities, which affect HbA1c, especially in those taking erythropoiesis-stimulating agents (ESAs). We aimed to find the effect of thyroid dysfunction on HbA1c in hemodialysis patients taking ESAs and those who do not. Materials and Method Fifty six patients were included in this study, which was done between September 2017 and June 2018, in Baghdad Teaching Hospital. Thyroid stimulating hormone, free T3, free T4 and HbA1c measurements were done. The patients were divided into 2 groups; those who took ESAs and those who did not, then they were subdivided into
... Show MoreSome physical properties enthalpy (?H), entropy (?s), free energy (?G),capacities(?cp?) and Pka values) for valine in dimethyl foramideover the temperature range 293.15-318.15K, were determined by direct conductance measurements. The acid dissociation at six temperature was examined at solvent composition x2) involving 0.141 of dimethyl foramide . As results, calculated values have been used to determine the dissociation constant and the associated thermodynamic function for the valine in the solvent mixture over temperatures in the range 293.15-318.15 k. The Pka1, and Pka2 were increased with increasing temperature.
Used cooking oil was undergoing trans-esterification reaction to produce biodiesel fuel. Method of production consisted of pretreatment steps, trans-esterification, separation, washing and drying. Trans-esterification of treated oils was studied at different operation conditions, the methanol to oil mole ratio were 6:1, 8:1, 10:1, and 12:1, at different temperature 30, 40, 50, and 60 º C, reaction time 40, 60, 80, and 120 minutes, amount of catalyst 0.5, 1, 1.5, and 2 wt.% based on oil and mixing speed 400 rpm. The maximum yield of biodiesel was 91.68 wt.% for treated oils obtained by trans-esterification reaction with 10:1 methanol to oil mole ratio, 60 º C reaction temperature, 80 minute reactio
... Show MoreThis paper aims to study the second-order geometric nonlinearity effects of P-Delta on the dynamic response of tall reinforced concrete buildings due to a wide range of earthquake ground motion forces, including minor earthquake up to moderate and strong earthquakes. The frequency domain dynamic analysis procedure was used for response assessment. Reinforced concrete building models with different heights up to 50 stories were analyzed. The finite element software ETABS (version 16.0.3) was used to analyze reinforced concrete building models.
The study reveals that the percentage increase in buildings' sway and drift due to P-Delta effects are nearly constant for specific building height irrespective of the seism
... Show MoreProblem of water scarcity is becoming common in many parts of the world. Thus to overcome this problem proper management of water and an efficient irrigation systems are needed. Irrigation with buried vertical ceramic pipe is known as a very effective in management of irrigation water. The two- dimensional transient flow of water from a buried vertical ceramic pipe through homogenous porous media is simulated numerically using the software HYDRUS/2D to predict empirical formulas that describe the predicted results accurately. Different values of pipe lengths and hydraulic conductivity were selected. In addition, different values of initial volumetric soil water content were assumed in this simulation a
... Show MoreThe issue of penalized regression model has received considerable critical attention to variable selection. It plays an essential role in dealing with high dimensional data. Arctangent denoted by the Atan penalty has been used in both estimation and variable selection as an efficient method recently. However, the Atan penalty is very sensitive to outliers in response to variables or heavy-tailed error distribution. While the least absolute deviation is a good method to get robustness in regression estimation. The specific objective of this research is to propose a robust Atan estimator from combining these two ideas at once. Simulation experiments and real data applications show that the proposed LAD-Atan estimator
... Show More<p>Analyzing X-rays and computed tomography-scan (CT scan) images using a convolutional neural network (CNN) method is a very interesting subject, especially after coronavirus disease 2019 (COVID-19) pandemic. In this paper, a study is made on 423 patients’ CT scan images from Al-Kadhimiya (Madenat Al Emammain Al Kadhmain) hospital in Baghdad, Iraq, to diagnose if they have COVID or not using CNN. The total data being tested has 15000 CT-scan images chosen in a specific way to give a correct diagnosis. The activation function used in this research is the wavelet function, which differs from CNN activation functions. The convolutional wavelet neural network (CWNN) model proposed in this paper is compared with regular convol
... Show MoreThis paper presents an efficient methodology to design modified evaporative air-cooler for winter air-conditioning in Baghdad city as well as using it for summer air-conditioning by adding a heating process after the humidification process. laboratory tests were performed on a direct evaporative cooler (DEC) followed by passing the air on hot water through heat exchanger placed in the coolers air duct exit. The tests were conducted on the 2nd of December /2011 when the ambient temperature was 8.1°C and the relative humidity was (68%). The air flow rate is assumed to vary between 0.069 to 0.209 kg/s with constant water flow rate of 0.03 kg/s in the heat exchanger. The performance is reported in terms of effectiveness of DEC, satura
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