ABSTRACT Background: Improving the properties of heat- cured and self-cured acrylic resin have been studied by many researchers. However, little studies concerned with visible light cured resin (VLCR) improved through addition of nanofiller are available. The purpose of this study was to evaluate some properties of (VLCR) after addition of SiO2 nanofiller. Materials and Methods: SiO2 nanofiller were added to (VLCR) tray material after being dissolved in tetrahydrofuran (THF) solvent. According to the pilot study 2% SiO2 nanofiller addition exhibited better properties than the other percentages (1%, 3%). The main study conducted involved (100) specimens divided into 5 groups according to the test included. (20) Specimens were selected for each test (10 samples for the control group and 10 samples for the experimental 2% SiO2 nanofiller group). The properties investigated were transverse strength, impact strength, surface hardness, surface roughness, water sorption and solubility. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) were used to assess nanofiller distribution and identification of elements. The data were subjected to descriptive statistical analysis and independent sample t-test. Results: The mean value of transverse strength of experimental group increased significantly, while the impact strength of experimental group decreased significantly when compared to control group. A significant increase in surface hardness was noticed in the experimental group, while non-significant increase in surface roughness was observed. The water sorption values were decreased significantly, while a non-significant decrease in water solubility was observed in the experimental group. Conclusion: Addition of SiO2 nanofiller to (VLCR), slightly improve the transverse strength and surface hardness, while water sorption and solubility slightly decreased. The impact strength was significantly deteriorated, while the surface roughness shows non-significant increment.
Violence is one of the most serious threats facing societies because it affects their internal structure and threatens the security and stability of society. It is classified as one of the types of security crises that are emerging in Arab and Islamic societies in particular, and in most countries of the world in general.
The threat of this crisis is increasing. Terrorism is considered as one of the most serious aspects of that all the countries of the world, currently, suffer from. The terrorism has begun to penetrate deep into society in one way or another starting from the Second World War, which led to the emergence of leftist movements in Western Europe, Japan, France, Italy and other countries as a result of emerging ideas
... Show MoreIt is obvious that the constitutional- political structures which has been emerged in Iraq after the occupation in 2003 frame worked by many sectarian, ethnic, tribal and political orientations, pushing forewords to escalating the contradictions between social- political powers, however, these changes unfortunately result not just destroy and taking apart the political regime and his authority, but the state and his institutions as well, although, did not stamped as wise and rational change for better future to new Iraq and its political, civil and military institutions. Finally, as quick as Iraq start to bisects to sectarian, ethnic and national components according to the new political – social components of Iraq. Indeed, what is req
... Show MoreThethesis of theresearch is to deal with relations between Russia and Yemen after 2011.That relationwas significant in different fields, historic, economic, strategic and cultural ones. There are mutual interestsbetweenRussia and Yemen, especially with the economic development and growth in Russia as an important partner to Yemen.Their has to an a great deal of progress in different types of relations, where as they were only partner in military relations. The studywasclassifiedintoto three sections: the first section dealt with strategic importance of Yemen to Russia. And second section dealt withthe military factor between Russia and Yemen. While the third section dealt with the economic factor between Russia and Yemen. In addi
... Show MoreThe topic of this research deals with an analytical study of the nature of the visual sent by the sculptural monument of the person of Christ around the world, the nature of this monument, the manner of its embodiment, the mechanism of reception for each of the societies that this monument addressed to them, how it was reflected on them, how it was reflected on them, and whether these works are related to their culture or not, I discussed this study All this, and the researcher has established theoretical research axes for the research according to the desired goal of this study, which is the definition of the mechanism of visual discourse of statues of Christ around the world and were as follows: (The first axis: the discourse and visua
... Show MoreThe fauna of bees (Hymenoptera, Apoidea) from different regions of Iraq is surveyed in this study; there were 16 species, 13 genera that belong to four families which are collected in this investigation.
Also, all the species that are recorded for Iraq in previous investigations are revised; totally there are 110 species, 32 genera belonging to five families: Apidae, Andernidae, Colletidae, Halictidae and Megachilidae were listed.
Globalisation and rapid environmental change have created many challenges for public and private organisations across Iraq as a developing country, particularly in the higher education sector. This includes, for example, decreases in government funding; increased demand for higher education; a need for economic transformation, and related competitiveness of organizations. Such challenges require exceptional leaders and strategic planning in order to take action to improve. In Iraq, the higher education sector is still one of the main foundations in progressing the knowledge economy. Studies into leadership style, strategic planning processes, and the importance of leadership and organisational culture to an organisation’s success have bee
... Show MoreThe main objective of this study is to determine whether the use of He-Ne Laser (632.8 nm wavelength and power 0.5 mW) is an eligible and effective tool to kill or reduce the cell viability of Candida albicans isolated from complete upper dentures. Twenty one swabs were taken from the complete upper dentures. Only six swabs showed positive cultures for C. albicans. The isolate was divided into two groups, group I was not irradiated (control), and group II was irradiated by He-Ne Laser for different periods (10, 15, 20, and 30) min. After irradiation, the results showed a significant reduction in the viable cell count and colonies diameters especially at exposure periods 10 and 15 min. Although the low power He-Ne Laser was not eradicating t
... Show MoreThe research aims to identify the extent to which Iraqi private banks practice profit management motivated by reducing the taxable base by increasing the provision for loan losses by relying on the LLP it model, which consists of a main independent variable (net profit before tax) and independent sub-variables (bank size, total debts to total equity, loans granted to total obligations) under the name of the variables governing the banking business. (Colmgrove-Smirnov) was used to test the normal distribution of data for all banks during the period 2017-2020, and then find the correlation between the main independent variable sub and the dependent variable by means of the correlation coefficient person, and then using the multiple
... Show MoreTo study the response of the celery plant to nitrogen fertilization and spray with salicylic acid in the leaves content of nutrients, the research was conducted in one of the fields of the Department of Horticulture and Gardening Engineering / College of Agriculture / University of Baghdad within the 2019-2018 season. The research was carried out as a global experiment and with the design of complete randomized sectors (RCBD) and with three replicates, the first factor included the addition of nitrogen with three levels and its symbol (N) (N1 control), (N2) g / m2 18 ), (N3) 37 g / m2 and the second factor spraying acid salicylic is denoted by
The Shiite religious authority in Iraq has played an active and vital role over its long history in promoting values of tolerance, rejecting extremism, advocating unity and confronting external challenges. This role has increased significantly after 2003 as a result of the great challenges that have passed in Iraq. Despite its clear policy of non-interference in political matters, except in cases of necessity, but the great role it played in maintaining national unity and advocating the rejection of extremism and sectarianism has made it a necessary need in Iraq to confront any deviations, dispersions or threats that affect society and the state. Therefore, its role in the process of reform was prominent on the political level by calling
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