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%).
The Plerion nebula is characterized by its pulsar that fills the center of the supernova remnant with radio and X-ray frequencies. In our galaxy there are nine naked plerionic systems known, of which the Crab Nebula is the best-known example. It has been studied this instance in order to investigate how the pulsar energy affect on the distribution and evolution of the remnant as well as study the pulsar kick velocity and its influence on the remnant. From the obtained results it's found that, the pulsar of the Crab Nebula injects about (2−3)𝑥 1047 erg of energy to the remnant, although this energy is small compared to the supernova explosion energy which is about 1051 erg but still plays a significant role in the distribution and the m
... Show MoreThe research consists of five chapters and aims to explore the administrative skills of leaders in physical education colleges and their relationship with administrative reform. The study sample included (deans, vice deans, and heads of departments) from physical education colleges for the academic year 2012-2013, with a total of 61 individuals. They were selected using the purposive sampling method, and the researcher distributed questionnaires to them, collecting 60 valid responses and excluding one due to its invalidity. After defining the concepts of administrative skills and administrative reform and redownloading relevant literature and previous studies, as well as consulting with a group of experts in management and psychology, the r
... Show MoreThe design of fabrics and fashion is manifested by aesthetic advantages betting with the movement of society in its quest to develop as an independent art in itself that is linked to the values and aesthetic concepts of other arts and what appears in them of intellectual systems calling for renewal and modernity. Which brought about a wide change in public taste, as well as a desire for innovation . Which made fashion an interesting aesthetic phenomenon and taste is always subject to change constantly to comply with the social variables that occur in human life, as the fashion that appears in a certain era of time and takes a great distance from spreading as something new and out of the ordinary is in fact the fruit of the development of
... Show MoreAbstractThe research aims to identify the impact of the different methods in calculating the Items sensitivity coefficient on the standard characteristics of the Criterion-Referenced test in the measurement and evaluation material. The research sample consisted of (35) male and female students, who were chosen by the intentional method. The researcher prepared learning-teaching program in constructing the content of the measurement and evaluation material for non-specialized departments, prepared an achievement test in its equivalent forms, identified the results of agreement between the methods used in analyzing the items of the criterion-referenced test, and compared the standard characteristics of the achievement test, both according to
... Show MoreWe propose a system to detect human faces in color images type BMP by using two methods RGB and YCbCr to determine which is the best one to be used, also determine the effect of applying Low pass filter, Contrast and Brightness on the image. In face detection we try to find the forehead from the binary image by scanning of the image that starts in the middle of the image then precedes by finding the continuous white pixel after continuous black pixel and the maximum width of the white pixel by scanning left and right vertically(sampled w) if the new width is half the previous one the scanning stops.
The aim of the current research is to identify the personal distance between members of society, as well as, to identify the feelings of satisfaction and positivity from respecting the permissible personal distance. The study also aims to identify the feelings of annoyance and comfort from approaching and going beyond personal distance and not respecting it. To achieve these goals, the researchers reviewed previous literature, theories, and studies that dealt with personal distance. The researchers reached a number of results; first, personal distance is not a law but rather a cultural guiding principle for social and professional morals. Second, there are four distances (intimate distance, the distance between friends, social distance,
... Show MoreThe Battle of Kadesh is replete with many military arrangements that reflect the tremendous development of war preparations in the thirteenth century BC; where the expressive pictures the Egyptians left on some of the walls of their temples show the tremendous ability to organize and divide the forces and the great development that affected the war machine. Furthermore, the text accompanied these pictures reveal some news about that battle, which is considered one of the most important wars in the ancient world. Thus, the importance of the study lies in the fact that it examines one of the most important battles of the ancient Near East, the results of which had great repercussions on the region. This is because it is the most abundant B
... Show MoreThe research aims to use performance indicators and financial criteria in evaluating the economic feasibility of the company's insurance portfolios. In addition to identifying the strengths and weaknesses in portfolio's performance to enhance the strengths and address the weaknesses. This is consistent with research problem that dealt with the performance indicators, economic feasibility of company's portfolios and contributing to their improvement, reducing the financial and insurance risks associated with company's business. The research’ sample is represented by the Iraqi Insurance Company as it is one of the oldest financial institutions operating in the insurance sector. It has identified (5) insurance portfolios (marine, engineer
... Show MoreThe research aims at identifying The Effect of Woods model in the Acquisition of Grammatical Concepts on students at the Sixth Primary. The total number of students is (49) male and female. students are distributed in two groups . The First group is the experimental group which is taught the( Woods Model) and it is (25) students . The second group is the control group which is taught according to the traditional method of teaching and it is (24) students . The researcher has matched between the two groups by the following variables : the age (in months), their intelligence, their parents, academic level of education . The research has constructed multiple choice test of (20) items . The reliability of The test has been calculated and it
... Show More