Background: Dentin removed during root canal system instrumentation for creating adequate geometry for the canal and cleaning the canal. A new instrument had been marketed with the aim of optimum shaping of all parts of the canal system, however, no information present about the amount of dentin removal compared to conventional rotary system. This study investigated the amount of dentin removal when the canal instrumented by SAF compared with ProTaper by using high resolution computed tomography (micro CT). Materials and Methods: Twenty extracted single canalled teeth were utilized for this study; and randomly divided into 2 groups. In the first group, the root canals were prepared by using protaper rotary system till F2 and the root canal irrigated with 1ml of normal saline after each instrument. The root canals in the second group were prepared using SAF for 2min, with continuous irrigation (normal saline). After rescanning, the amount of dentin removal was calculated. Result: It was clear that the use of SAF system had increase the amount of dentin removal and in quantity larger than that did by ProTaper system & the mean of net difference was (0.288mm ± 0.051). By using t-independent test, there was highly significant difference between the two groups at (p=0.001), with in favor of the SAF system over ProTaper system at p< 0.01; in dentin removal quantity Conclusion: Root canal preparation with SAF-system resulted in more and effectively removed dentin when compared with protaper rotary files.
The research aims to reveal the role of financial analysis in rationalizing the investor decision on the Iraqi stock Exchange market, by studying the relationship and impact techniques and methods of financial analysis on the decisions of investors in the market. The most important techniques and methods discussed in this study were: analysis (financial ratios analysis, comparison of financial statements analysis, cash flow statement analysis) for companies listed in the Iraqi stock Exchange market. The researcher adopted the analytical descriptive method which depends on the collection of data on the phenomenon and its interpretation. The questionnaire wa
... Show MoreCams are considered as one of the most important mechanical components that depends the contact action to do its job and suffer a lot of with drawbacks to be predicted and overcame in the design process. this work aims to investigate the induced cam contact and the maximum shear stress energy or (von misses) stresses during the course of action analytically using Hertz contact stress equation and the principal stress formulations to find the maximum stress value and its position beneath the contacting surfaces. The experimental investigation adopted two dimensions photoelastic technique to analyze cam stresses under a plane polarized light. The problem has been numerically simulated using Ansys software version 15 as FE
... Show MoreThis research is devoted to investigate the behavior and performance of reinforced concrete beams strengthened with externally bonded Carbon Fiber Reinforced Polymer (CFRP) laminates under the effect of torsion. In this study a theoretical analysis has been conducted using finite element code ANSYS. Six previously tested beams are used to investigate reinforced concrete beams behavior
under torsion, two of them are solid and the rest are box-section beams. Also, two beams are without CFRP reinforcement, which are used as control beams for the strengthened one, and the other four beams are strengthened with CFRP laminates with different number of layers and spacing. Numerical investigation is conducted on these beams, and comparisons b
This study deals with the aircraft wing analysis (numerical and experimental) which subjected to fatigue loading in order to analyze the aircraft wing numerically by using ANSYS 15.0 software and experimentally by using loading programs which effect on fatigue test specimens at laboratory to estimate life of used metal (aluminum alloy 7075-T651) the wing metal and compare between numerical and experimental work, as well as to formulate an experimental mathematical model which may find safe estimate for metals and most common alloys that are used to build aircraft wing at certain conditions. In experimental work, a (34) specimen of (aluminum alloy 7075-T651) were tested using alternating bending fatigue machine rig. The t
... Show MoreAnimation is an industry that is expanding more quickly than ever. Every child’s favorite activity is watching cartoons. Therefore, it is essential to be cautious of the kinds of cartoon films children and teenagers tend. Because children and teenagers are the target audience for these films. This study aims at exposing a hidden enactment, namely racism, in a well-known cartoon film, Lion King, which has been selected accurately by the researchers because it shapes a set of ideas about black people and constructs prejudiced beliefs in their minds. This study is to answer the inquiry ‘Is the ideology of racism imposed in Lion King? And how?’ The significance of the present paper lies in highlighting the educational function of
... Show MoreThe experimental and numerical analysis was performed on pipes suffering large plastic deformation through expanding them using rigid conical shaped mandrels, with three different cone angles (15◦, 25◦, 35◦) and diameters (15, 17, 20) mm. The experimental test for the strain results investigated the expanded areas. A numerical solution of the pipes expansion process was also investigated using the commercial finite element software ANSYS. The strains were measured for each case experimentally by stamping the mesh on the pipe after expanding, then compared with Ansys results. No cracks were generated during the process with the selected angles. It can be concluded that the strain decreased with greater angles of con
... Show MoreThe applications of Multilevel Converter (MLC) are increased because of the huge demand for clean power; especially these types of converters are compatible with the renewable energy sources. In addition, these new types of converters have the capability of high voltage and high power operation. A Nine-level converter in three modes of implementation; Diode Clamped-MLC (DC-MLC), Capacitor Clamped-MLC (CC-MLC), and the Modular Structured-MLC (MS-MLC) are analyzed and simulated in this paper. Various types of Multicarrier Modulation Techniques (MMTs) (Level shifted (LS), and Phase shifted (PS)) are used for operating the proposed Nine level - MLCs. Matlab/Simulink environment is used for the simulation, extracting, and ana
... Show MoreThe use of non-parametric models and subsequent estimation methods requires that many of the initial conditions that must be met to represent those models of society under study are appropriate, prompting researchers to look for more flexible models, which are represented by non-parametric models
In this study, the most important and most widespread estimations of the estimation of the nonlinear regression function were investigated using Nadaraya-Watson and Regression Local Ploynomial, which are one of the types of non-linear
... Show Morehe aim of the research is to clarify the meanings and connotations of (Semitic), and to identify the peoples that fell under this name according to historical data, biblical texts and Qur’anic news. International sympathy on the one hand and on the other hand controlling the land of Palestine and giving them international legitimacy to grow their entity according to global support and sympathy with their alleged slogan (anti-Semitism), which revolves around the oppression of the Jews.