Background: The aim of this study was to measure the radiopacity (RO) of modified microhybrid composite resins by adding 2 types of nanofillers (Zinc Oxide and Calcium Carbonate) in two concentrations 3% and 5% and comparing them to unmodified microhybrid composite resins and to nanofilled composite resin. Materials and Methods: Two types of composite resin were used (Microhybrid composite MH Quadrent anterior shine and Nanofilled composite resin Filtek Z350 XT), for each tested group five disk-shaped specimens (1-mm-thick and 15 mm diameter) were fabricated. The material samples were radiographed together with the aluminum step wedge. The density of the specimens was determined with a transmission densitometer and was expressed in term of equivalent thickness of aluminum. Data analyzed by one-way ANOVA. Results: The radiopacity (RO) values of the tested group ranged between (0.9293- 2.6242 Eq. Al thickness) and there were significant differences among them. Nanofilled composite resin Filtek Z350 XT showed the highest value of RO while unmodified Microhybrid composite MH Quadrent anterior shine showed the lowest value of RO. Conclusion: The addition of 3% of both the ZnO and CaCO3 nanofillers fillers to microhybrid composite significantly increased the RO, while the addition of 5% of CaCO3 and ZnO nanofillers to microhybrid composite showed non-significant increase in the RO of the composite.
The recent advances in technology, the increased dependence on electrical energy and the emergence of the fourth industrial revolution (Industry 4.0) were all factors in the increased need for smart, efficient and reliable energy systems. This introduced the concept of the Smart Grid (SG). A SG is a potential replacement for older power grids, capable of adapting and distributing energy based on demand. SG systems are complex. They combine various components and have high requirements for real time reliable operation. This paper attempts to provide an overview of SG systems, by outlining SG architecture and various components. It also introduces communication technologies, integration and network management tools that are involved in SG sys
... Show MoreMeaning letters in Arabic are characterized by the diversity and abundance of their linguistic material, and are also distinguished by their large number and types, to the point that some of them have reached a hundred letters confined to five categories
In spite of economic importance of sugar cane and sugar beet as they described as industrial crops they still face decreasing rates of production and productivity in Iraq , and their production was not able to satisfy the local industrial demands for sugar . Thus this study aimed at studying and analyzing, production and productivity of sugar cane and sugar beet in Iraq and this has been done by using non serial data that can be obtained from official offices in Iraq . The area and production of sugar cane in Iraq recorded positive annual growth rates during 1970- 1978 which were 6% and 5% consequently , while the productivity of sugar cane recorded at the same duration of time negative annual growth rate which was 1% , while they recorded
... Show MoreAnastatica Hierochuntica L. Used As an Alternative of Conjugated Estrogen (Premarin) in Rabbit Females
This study investigates the influence of fear, refuge, and migration in a predator–prey model, where the interactions between the species follow an asymmetric function response. In contrast to some other findings, we propose that prey develop an anti-predator response in response to a concentration of predators, which in turn increases the fear factor of the predators. The conditions under which all ecologically meaningful equilibrium points exist are discussed in detail. The local and global dynamics of the model are determined at all equilibrium points. The model admits several interesting results by changing the rate of fear of predators and predator aggregate sensitivity. Numerical simulations have been performed to verify our theoret
... Show MoreThere are risks and benefits with all medicines and estrogen replacement is no exception. In fact, estrogen replacement is one of the most controversial topics in Endocrinology. Anastatica hierochuntica L. is a popular treatment for the management of female reproductive disorders. The present research highlights the effect of aqueous extract of plant against conjugated estrogen(Premarin) in rabbits. Femal oryciolagus cuniculus rabbits were divided into four groups: the 1 st group, rabbits were orally administered (using a feeding solution )with daily dose(5 mL distilled water)for two months, the 2nd group, the rabbits were treated with conjugated estrogen (50 µg/kg b.w, body weight )for one month. The 3rd group, the rabbits were treated w
... Show MoreSimulation of free convection heat transfer in a square enclosure induced by heated thin plate is represented numerically. All the enclosure walls have constant temperature lower than the plate’s temperature. The flow is assumed to be two-dimensional. The discretized equations were solved stream function, vorticity, and energy equations by finite difference method using explicit technique and Successive Over- Relaxation method. The study was performed for different values of Rayleigh number ranging from 103 to 105 for different angle position of heated thin plate(0°, 45°, 90°). Air was chosen as a working fluid (Pr = 0.71). Aspect ratio of center of plate to the parallel left wall A2
... Show MoreThe current research aims to evaluate the level of inclusive leadership within the General Secretariat for the Council of Ministers, and its role in achieving integration in work through the need to improve relationships between different administrative levels, facilitate participation, expression of opinions, and belonging to the organization. In order to achieve the research objective, the descriptive analytical statistical method was chosen using the SPSS V.25 programs, with various statistical methods and measures, including mean, standard deviation, variance coefficient, relative importance, and simple regression, through a questionnaire tool for data collection. The research community included the leadership in the sample of resear
... Show MoreTraining and retraining of teachers have become a central issue in Iraq recently especially in-service training of English teachers on the new curricula (Iraq opportunities). English teachers should be objectively evaluated and assessed.
A sample of (40) trained teachers of English is included in the study and a questionnaire is used as the main instrument of the study.
The main findings of the study were the following:
1. The trainees were serious in training on the new course (item 6) the programme helped increase their information (item 4) and motivate them towards better teaching (item 3). The aims of the programme were clear (item1). The programme helped develop their teaching skills (item 2) and was comprehensive (item 5).