In this research, damping properties for composite materials were evaluated using logarithmic decrement method to study the effect of reinforcements on the damping ratio of the epoxy matrix. Three stages of composites were prepared in this research. The first stage included preparing binary blends of epoxy (EP) and different weight percentages of polysulfide rubber (PSR) (0%, 2.5%, 5%, 7.5% and 10%). It was found that the weight percentage 5% of polysulfide was the best percentage, which gives the best mechanical properties for the blend matrix. The advantage of this blend matrix is that; it mediates between the brittle properties of epoxy and the flexible properties of a blend matrix with the highest percentage of PSR. The second stage included reinforcing the best blend matrix of epoxy-polysulfide (the blend matrix with the best percentage of polysulfide resulted from the previous stage), by different volume percentages of short fibers (Carbon& Glass) separately and randomly. The volume percentages of fibers were (2.5%, 5%, 7.5%, and 10%). The third stage included reinforcing the blend composites with highest percentages of carbon and glass fiber, by different weight percentages of nano-particles (Red mud& Fly ash) separately. The weight percentages of particles were (0.5%, 1%, 1.5%, and 2%). The experimental results showed that blending polysulfide rubber with epoxy increased the damping ratio. As for reinforcement materials, they decreased the damping ratio, where glass fiber composites have significantly higher damping ratio than other composites.
Background: Salivary immunoglobulin IgA plays an essential role in the immune response against dental caries. This studywas conducted to compare the salivary IgA levels and flow rate of stimulated saliva in caries active and caries free children. Materials and methods: The present study included sixty healthy children age 7-10 yearswho were divided into two groups. They were caries free and caries active children (30 children in each group). Assessment and recording of caries – experience were through the application of Decayed, Missing and Filled Tooth Index (DMFT) and (dmft) index, for permanent and deciduous teeth respectively. After dental examination, stimulated saliva samples were collected from the subjects and performed und
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The current research aims at highlighting the role of engagement of a sample of employees who works in some of the Iraqi private banks in terms of their interaction , commitment and enthusiasm and the positive impact they own regarding their job and devote their efforts to achieve the core purpose which is customer loyalty. The problem was expressed through a number of intellectual and practical questions.
In order to achieve the aim of the research the quantitative analytical method was used depending on a questionnaire as a basic tool to collect research data and the qualitative survey method depending on semi-structured interviews which were distrib
... Show MoreIn this research, we studied the multiple linear regression models for two variables in the presence of the autocorrelation problem for the error term observations and when the error is distributed with general logistic distribution. The auto regression model is involved in the studying and analyzing of the relationship between the variables, and through this relationship, the forecasting is completed with the variables as values. A simulation technique is used for comparison methods depending
This study aimed to identify the attitudes of school teachers and principals at basic government schools in Ajloun governorate towards the inclusion of disabled students at basic schools, and investigate how they will accept the merger. To achieve the purpose of this study, a questionnaire containing 35 items was administered to school teachers and principals to measure their attitudes toward the inclusion of disabled students in regular schools. The sample of this study consisted of 43 male teachers and (74) female teachers and principals. The frequency, normal distribution, arithmetic means and t-test were used to analyze the data of present study. The findings showed that there
... Show MoreAcademic boredom is one of the most emotional problems that arouse an individual's fatigueness and lowers his interest. This is because of the environment's low efficiency and of spending long monotonous time. This state is characterized by having lack of interest, difficulties in concentration, and the desire to leave the class. It is considered one of the most prominent forms of boredom widespread among students and the most severe and dangerous one that has negative effects and severe psychological and social problems. The current research aims to investigate a randomly selected sample of 335 students from the first and third grades at the directorates of education (Karkh and Rusafa) who suffers from academic boredom. Similarily
... Show MoreBackground: Obesity is an evolving major health problem in both developed and developing countries. Traditional obesity indices as body mass index, waist circumference, waist-hip-ratio are well known measures to identify obese subjects, however, neck circumference as an index of upper-body obesity was found to be a simple and time-saving screening measure that can be used to identify obesity and the likelihood of developing metabolic syndrome in type 2 diabetic patients.
Aim: to investigate the relationship of neck circumference (NC) to obesity and metabolic syndrome in Iraqi subjects with type 2 diabetes.
Methods: The study group included 90 type 2 diabetic subjects (48 men and 42 women) aged 30-68 years. The subjects were those w
Plumbago (Plumbaginaceae) is a genus of 10-20 species of flowering plants used in traditional Indian medicine, native to warm temperature to tropical regions of the world. The roots of Plumbago europaea, the Iraqi species of Plumbago, have been used for the treatment of cancer, rheumatoid arthritis, and dysmenorrhea. The main active constituents from dried powdered leaves and roots of Plumbago europaea were extracted by Soxhlet apparatus using ethyl acetate, the main active constituent was characterized by spectroscopic analysis (IR, 1H NMR, and 13C NMR) as plumbagin. Quantitative and qualitative study of plumbagin in the roots and leaves extracts was carried out by HP
... Show MoreEuphemisms are advantageous in people’s social life by turning sensitive into a more acceptable ones so that resentful feelings and embarrassment can be avoided. This study investigates the ability of Iraqi English learners in using euphemistic expressions, meanwhile, raising their awareness and the faculty members in English teaching faculties regarding the relevance of discussing the topics that demand euphemisation. This study comprised three stages: initial test, explicit instruction with activities, and a final test for the students’ development in this domain. A test has been distributed among 50 respondents, who are at the fourth year of their undergraduate study at the University of Babylon/ College of Basic Education. The lo
... Show MoreThe study aimed to prepare psychological measures of intellectual emptiness and mental distraction on university students. The two researchers used the descriptive approach in the two methods of surveying and correlational relations to suit the nature of the research, where the study sample consisted of (101) students of physical education and sports sciences. The phrase- Intellectual emptiness(35) and (34) is a phrase for mental distraction and presented it to experts in psychology, testing and measurement, and the statistical bag for social sciences (spss) was used, and the results of the research showed that intellectual emptiness has a moral relationship with straying among some students of the College of Physical Education
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