The article describes a study on the role of vitamin C as a protective agent for the teeth, gum, and implants using quantum chemical calculations and polarization tests. The Density Functional Theory (DFT) at 6-311G (d, p) basis set is used to estimate the ability of vitamin C to inhibit the corrosion of the abovementioned parts. The experimental study was performed in a at human body media simulator (Hank’s balanced salt solution) at a temperature of 37°C. The compound was optimized for its ground state, physical properties, and corrosion parameters. Further, HOMO, LUMO, energy gap, dipole moment, and other parameters were used to predict the inhibitor’s efficiency. Gaussian 09, UCA-FUKUI, MGL tools, DSV, and LigPlus software was used. According to electron density, Electrostatic Surface (ESP), Total Electron Density (TED), FUKUI function, and dual descriptor were used to show the active sites of adsorption. Also, docking studies were applied to predict the effect of vitamin C on A. ferrooxidans bacteria, which causes eroding the implants. The Ti6Al4V alloy was tested at three concentrations of the VC inhibitor using the polarization method. A concentration of 55 mg/L is the best in terms of inhibitor efficiency (99.62%).
We notice that the issue of development is one of the most important issues in ourepoch especially in our country which classify within back ward countries.
When we talk here about the development we don’t mean only the development of capitals or the development of products.but the most important thing is the development of mind .if we notice the experience of developits economy and it didn’t reach to the wanted aim.because these sides . The highness of the meutal rate of the nation is the standard of of the nation is the standard of the sentific and cultural advance for this nation .And that is what we have noticed in human societies ingenerall .
We noticed that
... Show MoreThis study aimed to clarify the legal provisions concerning the senses and their role in financial transactions, in the light of the definition of all the vocabulary presented by this study (senses - the definition of senses apparent: they are hearing - sight - smell - taste - touch) in the first section. The study deals with the second topic of the reference and writing denominator phrase and includes two requirements, the first requirement: the establishment of the denominator of the phrase, which has two branches: Section I: signal Akhras. Section II: Signal of the Spokesman.
The second requirement is that writing takes the place of the phrase in financial transactions. The owners argue that the sale of the blind is correct a
Phraseological or phraseological turn - unchanged in structure and composition, integral in meaning and lexically indivisible phrase or sentence, performing the function of a separate dictionary unit - lexemes. Idioms are found in any language of the world. But such a number of winged phrases, as in Russian, is nowhere else. Idioms play a role in displaying the national-cultural characteristics of any language. They very clearly and accurately reflect the characteristics of the perception of the world, the characteristic features of the material and spiritual life of native speakers, his mentality.
The study tries to answer several questions posed by the subject, one of the important: How the Internet promotes rumor? And what are the most Internet applications that promote rumor? And the practical ways to reduce these negative? Using the process of in vestige and reading theoretical heritage available in this field, and inferred the numbers and statistics marked the uses of the Internet and its applications over recent years, and the characteristics of each these tools in the field of collection, processing, and dissemination of information
As the child is growing up, he goes through different phases which will be accompanied by physical and psychological changes. These changes set the basis for processes of designing and making children's clothes which in turn give its required benefits and meet the physiological, psychological and community needs. That will help provide the child with healthy physical and psychological growth.
The aim of this research is to recognize the decoration of clothes by colors and drawings and its role in clothes' richness and children's education. The research limits are objective, The limits are for female (3-5) years old. The research was done in teaching kindergarten in the college of education for women in 2016. The researchers found many
The mechanical function of the heart is governed by the contractile properties of the cells, the mechanical stiffness of the muscle and connective tissue, and pressure and volume loading conditions on the organ. Although ventricular pressures and volumes are available for assessing the global pumping performance of the heart, the distribution of stress and strain that characterize regional ventricular function and change in cell biology must be known. The mechanics of the equatorial region of the left, ventricle was modeled by a thick-walled cylinder. The tangential (circumferential) stress, radial stress and longitudinal stress in the wall of the heart have been calculated. There are also significant torsional shear in the wall during b
... Show MoreIraq has confronted a huge political transformations after 2003 which resembled and presented rapid changes from totalitarian regime into democracy's system , this phenomenon has become a feature embodied in a new political system, specifically is being a price for previous deprivation and despotism .So that, the nature of political work has been changed as a result of practicing new democratic values ,but the real challenges appeared by depending on the conformity and political compromise in dealing with all of crises and problems in the political life .
The future of political work in this nascent democracy could be prepared according to fulfillment an active doings values stretched on national unity and forgiveness from one side ,t
Abstract:
This tribe had lived in Iraq since the first century A.D. Persia tried to
keep this tribe away from Iraq, but without result. The tribe managed to get
victory against Persia in the battle of Dhyqar.
When the Muslims had come to conquer Iraq, Rabi’a welcomed them
and takes part in that action.
That tribe helped the caliph Ali in the Jammal and Sifffen wars in order
to remain Iraq the center of the Islamic caliphates this tribe had felt very sad
and sorrowful when the caliphate become to the Umayyad . This tribe did not
give up, so this tribe did what could be done to help those who had revolted
against the Umayyad. Rabi’a did that in order to get ride of the Mudriat alsham,
and favored Rabi
The fouling depositions of crude oil stream were studied theoretically in a shell and tube heat exchanger to investigate the effect of depositions on the heat transfer process. The employed heat exchanger was with steam flowing in the inner tubes and crude oil in the shell at different velocities and bulk temperatures. It is assumed that fouling occurs only on the heated stream side (crude oil). The analysis was carried out for turbulent flow heat transfer conditions with wide range of Reynolds number, bulk temperature and time. Many previously proposed models for fouling resistance were employed to estimate a new model for fouling rate. It is found that the fouling rate and consequently the heat transfer coefficient were affected by Rey
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