Background: The fracture of instruments within root canal during endodontic treatment is a common incidence, fracture because of fatigue through flexure occurs due to metal fatigue, this study aimed to assess the effect of curvature angle and rotational speed on the cyclic fatigue of different type of Endodontic NiTi Rotary Instruments and compare among them. Materials and method: Three types of rotary instruments with tip size 0.25: ProTaPer F2 (Densply, Malifier) Revo-S SU( 0.06 taper, MicroMega) and RaCe system (0.06 taper, FKG, Dentaire), Forty file of each instrument were used within two canals with angle of curvature (40 &60 )at two speed (250&400)RPM, twelve group were formed for all instruments(total number=120),ten file for each group. The testing canals customized within stainless steel block covered with glass face, the time to fracture recorded and the mean of cycles to fracture (MCF) detected for each instrument. Data were analyzed statistically by ANOVA, LSD and Independent T-test at 5% significant level. Result: there was a highly significant difference of curvature angle and significant difference of rotational speed on the fracture resistance of instruments. RaCe revealed the best fracture resistance followed by ProTaper then Revo-S that showed the less resistance. Conclusion: The rotary instruments more prone to fracture when used at more curvature angle and higher rotational speed, as well as the rotary instruments differ from each other according to manufacturing process, taper, cross section and other factors.
In this paper, a cognitive system based on a nonlinear neural controller and intelligent algorithm that will guide an autonomous mobile robot during continuous path-tracking and navigate over solid obstacles with avoidance was proposed. The goal of the proposed structure is to plan and track the reference path equation for the autonomous mobile robot in the mining environment to avoid the obstacles and reach to the target position by using intelligent optimization algorithms. Particle Swarm Optimization (PSO) and Artificial Bee Colony (ABC) Algorithms are used to finding the solutions of the mobile robot navigation problems in the mine by searching the optimal paths and finding the reference path equation of the optimal
... Show More
(3)
Background: The vasoconstricting agents: nor-adrenaline and 5- hydroxytryptamine
(5-HT) have a stimulant action on smooth muscle contractility of the rat vas deferens.
Objective: This study aimed to investigate the effect of exposure to continuous
darkness and continuous light on the contractility of the vasa deferntia smooth
muscles from rats to applied nor-adrenaline and 5-HT.
Method: Male albino wistar rats were divided into 3 experimental groups. Group 1:
Control animals, were exposed to the ordinary photoperiod each day. Group 2: Rats
were kept in a dark room. Group 3: In a room under a bright artificial light.
All animals were killed after 4 weeks.
Results: Vasa deferentia preparations from continuous dar
Objective: To identify the effect of the cube model on visual-spatial intelligence and learning the skill of spikinging in volleyball for female students, The researchers used the experimental method by designing two equivalent groups with pre- and post-measurements. Research methodology: The main research sample of (30) female students was selected from the research community represented by second-stage students in the College of Physical Education and Sports Sciences - University of Baghdad for the academic year (2024-2025). The sample was divided equally into two control and experimental groups. The researchers conducted the sample homogenization process and the equivalence process between the two groups in the variables of visua
... Show More
Autorías: Muayad Kadhim Raheem, Lina Fouad Jawad. Localización: Opción: Revista de Ciencias Humanas y Sociales. Nº. 21, 2019. Artículo de Revista en Dialnet.
The current study was conducted to find out the effect of the sediment source (sedimentary of Iraqi-Iranian borderline and Tigris River) on the content and distribution of feldspar minerals and their effect on the optical properties of these minerals in some soils of Wasit and Maysan province. Eight pedons were chosen to represent the study area, five of them represented sediments coming from the borderline, which included pedons of (Badra, Taj Al-Din, Al-Shihabi, Jassan, and Galat), while two of them represent the sediments of the Tigris River (Essaouira, Al-Dabouni). Finally, the pedon of Ali Al-Gharbi represented the mixing area of sediments of all the torrents coming from borderline and the sediments of the Tigris River. The diagnostic
... Show More
(1)
Purpose: To determine the impact of service encounter in stimulating voluntary customer behaviors.
- Approach / methodology: It was selected a sample of customers Bank Iraqi Trade (TBI) was (105) individual, using a questionnaire designed in the light of previous studies, was drafted scale and tested in the light of a group of statistical methods developed (reliability coefficient, reliability coefficient composite, convergence). Then test hypotheses through structural equation modeling.
- Results: The behaviors and characteristics of the service provider in effect urged bank customers to perform voluntary extra, as the service environment service encounter
This study focusses on the effect of using ICA transform on the classification accuracy of satellite images using the maximum likelihood classifier. The study area represents an agricultural area north of the capital Baghdad - Iraq, as it was captured by the Landsat 8 satellite on 12 January 2021, where the bands of the OLI sensor were used. A field visit was made to a variety of classes that represent the landcover of the study area and the geographical location of these classes was recorded. Gaussian, Kurtosis, and LogCosh kernels were used to perform the ICA transform of the OLI Landsat 8 image. Different training sets were made for each of the ICA and Landsat 8 images separately that used in the classification phase, and used to calcula
... Show More
The study aimed to clarify the meanings learned and inferred from reading books، letters and messages in Surat Al-Qur’an. The inductive method، the analytical method، and the deductive method، One of the most prominent results of the research: that the multiplicity of Qur’anic readings produces a variety and expansion in the meaning that has a clear impact on the interpretation by clarifying the meaning of the verse.
Hydroxide upon the chemical composition and dry matter(DM) and organic matter(OM) digestibility . Rice straw was treated with 4% sodium hydroxide using 30% of DM basis moisture, and incubated at 40 ºC for 40 days., DM digestibility (DMD) was significantly affected (P<0.01) by the treatment , where DMD increased The objective of this experiment was to study the effect of physical form (long ,chopped and ground ) and washing rice straw treated with sodium from 42.32 to 45.41% , OM digestibility (OMD) and total digestible nutrient (TDN) increased(P<0.05) from 47.38 and 49.33 to 49.67 and 52.83% ,respectively. While hemicellulose content increased (P<0.05 ) from 261.71 to 268.17 gm/kg DM ,and metabolizable energy (ME) from 7.11 to 7.48 MJ/
... Show More
Objectives: To Assess the Effect of Physical Status of Polycystic Ovarian Syndrome on Women in Reproductive Age,
To Find out the Relationship Between Polycystic Ovarian Syndrome and Women's Physical Health (Acne , Hirsutism ,
Weight Gain , Irregular Menstrual Period),&To Identify the Association of Physical Status to polycystic ovarian
syndrome and Some Socio Demographic Characteristic (Age ,Occupation & Obesity ), and Reproductive
Characteristic(Gravida ,Para ,Abortion &Menstrual Regularity).
Methodology :a descriptive analytical study was conduct on Non-probability (purposive sample) of (100)women who
suffering from polycystic ovarian syndrome in reproductive age in infertility counseling from three hospit