Background: Alterations in the microhardness and roughness are commonly used to analyze the possible negative effects of bleaching products on restorative materials. This in vitro study evaluated the effect of in-office bleaching (SDI pola office +) on the surface roughness and micro-hardness of four newly developed composite materials (Z350XT –nano-filled, Z250XT-nano-hybrid, Z250-mico-hybrid and Silorane-silorane based). Materials and methods: Eighty circular samples with A3 shading were prepared by using Teflon mold 2mm thickness and 10mm in diameter. 20 samples for each material, 10 samples for base line measurement (surface roughness by using portable profillometer, and micro-hardness by usingDigital Micro Vickers Hardness Tester), and 10 samples for after bleaching measurement. The appropriate bleaching procedure was performed on the top surface of test groups for 90 minutes total bleaching period. Then surface roughness and hardness were tested at the end of the duration. Statistical analysis was carried out using ANOVA, LSD and t-test. Results: There was a highly significant increase in surface roughness of all tested groups after bleaching. There is a highly significant increase in micro-hardness for Z250, there is decrease in Micro-hardness for siloraneand Z250xt and there is a non-significant increase in micro-hardness of Z350xt. Conclusion: bleaching has a negative effect on surface roughness of all the tested materials, as surface roughness increased after bleaching. Micro-hardness is a material dependent, there is different reaction to bleaching depending on the resin, load and size of the fillers used in the materials. Nano-filled composite is the material that has better performance than the other tested materials, as it is the material that has the least affection by bleaching.
Abstract:
Witness the current business environment changes rapidly reflected on the performance of the facility wishing to stay , which is no longer style reaction enough to handle installations with their environment , and quickly began to lose its luster with the emergence of a message and the vision of contemporary business environment from a set of parts interacting with each other and the concept of behavioral includes all dimensions of performance, it is imperative to adopt a system installations influence variables and positive interaction through the development of strategic plans and the use of implementation and follow-up strategies to ensure the effectiveness of the method for meas
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This research aims to find out the phonemic, dialect and semantic ailments that were interrogated by the book of the parsing of thirty surahs of the Noble Qur’an by Ibn Khalawiyeh, by examining some phonemic phenomena of Qur’anic expressions and their explanatory relationships that resulted in their occurrence, such as substitution and compression, as the sounds in a word are affected by one another, especially during performance and composition. This influence and influence is the tendency of the human being to the law of ease, facilitation, and the reduction of muscular effort in speech often, all for the purpose of obtaining phonemic harmony for the compound letters; To facilitate pronunciation; And get rid of the muscular effort
... Show MoreThe study of the subject of (Egyptian public opinion on the Libyan revolution) came to reveal the role of Egyptian public opinion in mobilizing and solidarity for the masses. With the events witnessed by the Arab countries before the revolution, this was evident by the people 's attitudes towards the tripartite aggression against Egypt in 1956, and the June 1967 war, and the most recent what the Egyptian people showed towards the Libyan revolution. The Egyptian press followed the completion of the arms deal with France and revealed the ability of the Libyan negotiator to achieve moral gain, supported by Egyptian support to thwart the United States intentions to arm "Israel" similarly. The Egyptian people expressed a love for peace and su
... Show MoreIn this study was undertaken frish fish such as Bigeye Ilisha megaloptera, Nematalos nasus, Suboor Hilsha ilisha and Carp Cyprinus carpio. they were purchased from local marketes in Basrah, Oil was extracted by a solvent extraction method on low temperature. And the level of oil obtiened about (6.08; 10.72; 13.52 and 5.61)% for Bigeye, Jaffout, Suboor and Carp. the Crud oils were compared with vegetable oil (olive oil) and animal fat (tial fat mutton).
The extracted oil from fresh complete fishs with compared oils intraed on pharmacological system through packed in capsul with and with out garlic`s extract. this system analysis with chemical tests.
Results were analyzed statistically by using the SPSS program with using (CRD)
Anti-Toxoplasma gondii seropositive status among obese and diabetic patients has recently attracted substantial attention. The objective of this study was to assess the seropositive rate of T. gondii and its relation to high body mass index (BMI), diabetes, and metabolic syndrome among participants (n=100) who attended Al-Kadhimiya Teaching Hospital, Baghdad-Iraq. An observational analytical study was conducted from October 2019 to March 2020. Participants were divided into three groups based on their BMI; obese (n=38), overweight (n=32) and normal (n=30). In addition, they were divided into diabetic (n=45) and non-diabetic (n=55) based on clinical examination, laboratory examination, and medical interview. Another clas
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Baghdad University Radio Telescope (BURT) is a 3 meter radio telescope that was installed in the main campus of the University of Baghdad in Jadiriyah. Radio telescopes, in general, offer a wide range of applications in radio astronomy, which are usually used to detect the neutral hydrogen emission line at a wavelength of 21 cm. One of the key applications of BURT is to observe the Milky Way galaxy and to determine its rotation curve. However, performing such observations requires accurate determination of the appropriate observing time as well as the coordinates. This paper focuses on how the observing time and coordinates are calculated correctly and accurately. The horizontal coordinate that corresponds to the galactic coor
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Coherent density fluctuation model (CDFM) has been used to calculate the
proton momentum distributions (PMD) and elastic electron scattering form factors,
F(q), of the ground state for some even mass nuclei of fp-shell, such as 52Cr, 58Fe and
64Ni nuclei. Both of the PMD and F(q) have been expressed in terms of the weight
function ( ( ) )
2
f x which is determined by means of the charge density
distributions (CDD) of the nuclei and determined from theory and experiment. The
feature of the long-tail behavior at high momentum region of the PMD’s has been
obtained by both the theoretical and experimental weight functions. The calculated
form factors of these nuclei are in reasonable agreement with those of th
It is evident from this study that Yamama Formation is reservoir rocks and source rocks at the same time, based on occurrences of crude oil and source rocks. Bulk properties of Yamama oil in six wells as well as comparing several samples of Yamama oil by using the biological mark have indicated multi source of hydrocarbons with some pay having Jurassic and Lower Cretaceouse source affinity that belongs to the Yamama Formation.
The follower of the needs of the users of accounting information notices the necessity of adopting faithful representation of information Hence, IASB adopted the economic substance approach as the basis for the Formulation and development of international accounting standards Therefore, this research discusses the reflection of the economic phenomenon in terms of its economic substance on the subject of measurement , And it should be consistent measurement method where the problem of research is concentrated in the fact that the economic units operating in the local environment to address events and economic phenomena according to the legal form , as appropriate With the requirements of the unified accounting sys
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