The reduction of vibration properties for composite material (woven roving E-glass fiber plies in thermosetting polyester matrix) is investigated at the prediction time under varied combined temperatures (60 to -15) using three types of boundary conditions like (CFCF, CCCF, and CFCC). The vibration properties are the amplitude, natural frequency, dynamic elastic moduli (young modulus in x, y directions and shear modulus in 1, 2 plane) and damping factor. The natural frequency of a system is a function of its elastic properties, dimensions, and mass. The woven roving glass fiber has been especially engineered for polymer reinforcement; but the unsaturated thermosetting polyester is widely used, offering a good balance of vibration properties at moderate or ambient temperatures, and also at relatively low cost. The mismatch between matrix and fiber yarns gives a predominant role for the fiber's mechanics where the matrix is the area where most damage mechanisms develop. The free vibration test was carried out for (5, 10, 15, 20, 25, 30) minutes. The composite plate was exposed to (75) of thermal gradient for ten times in various times at different stages. The results were classified into experimental and finite element using software ANSYS Ver. 9.
The purpose of the study is to investigate the effect of the constructivist model of yager in acquiring the geographical concepts among first intermediate students in geography. The study was carried on based on the null hypothesis, which states, there is no significant difference at the level of (0.05) between the experimental group that follows yager model in learning the principles of geography, and the control group that studies the same subject considering the traditional methods of learning, the. To do so, a sample of (70) first-intermediate student were chosen purposefully from two random class for the academic year (2016-2017) divided into two groups. The selected schools located at Al-rusafa side in the city of Baghdad, as well
... Show Morethis research aims to identify the impact of teaching with ana logies in collection of chemistry students grade average.And direction in order to verify to the zero hypothesis has been formulated and validated,The researcher conducted experiment lasted a full semester as experimental design was chosen (exactly)two equal one pilot and another officer.The research community has been selected one of intentional Middle School of the Education Directorate in B aghdad Karkh second either search sample consisted of (68) students from second grade average (34 ) Students for each group randomly selected research groups was equal to the following variables (lifetime months,parent of first grade chemistry degrees average test informat
... Show MoreThe aim of this study was to study TV advertising and consumer behavior in children and to meet the needs of children. The study included 100 children from Baghdad who were randomly selected from different regions ranging in age from 9-12 years of both males and females. The current research was based on the interview and the completion of special forms prepared for this purpose. This age group was selected for the rare studies conducted on television advertising and limited to different sectors. Data on age and sex were documented, as the results of this study proved The afternoon period was the preferred period for watching the TV show in males, where it was 22%, while the morning period was the female favorite, and it was 23%. The ind
... Show MoreNumerical simulations have been carried out on the solar chimney power plant systems. This paper gives the flow field analysis for a solar chimney power generation project located in Baghdad. The continuity, Naver-stockes, energy and radiation transfer equations have been solved and carried out by Fluent software. The governing equations are solved for incompressible, 3-D, steady state, turbulent is approximated by a standard k - model with Boussiuesq approximation to study and evaluate the performance of solar chimney power plant in Baghdad city of Iraq. The different geometric parameters of project are assumed such as collector diameter and chimney height at different working conditions of solar radiation intensity (300,450,600,750
... Show MoreObjective(s): The present study aims at identifying the Iraqi Colleges of Nursing Deans' leadership
behaviors effectiveness and faculty members' motivation towards work in these colleges.
Methodology: Descriptive design has been used for the sample survey manner, which is the
appropriate approach to the study of social phenomena in the field where provides data on the reality of
these phenomena and relations between the causes and consequences and an analysis of it and perhaps
the factors affecting it and how it appears. The study relies on a questionnaire to collect data from the
participants which is composed of (86) items distributed on three axes: First, the demographic
characteristics which are composed of (8) i
In this experimental and numerical analysis, three varieties of under-reamed piles comprising one bulb were used. The location of the bulb changes from pile to pile, as it is found at the bottom, center, and top of the pile, respectively.
This research aims to examine the relationship between learning organization and behavior of work teams. The variable of the learning organization took four dimensions depending on the study (sudhartna & Li, 2004): Common cultural values , communication, knowledge transfer and the characteristics of workers. The behavior of teams was identified on the basis of realizing of the respondents of their organization to work as a team where the research relied concepts applied in the study (Hakim , 2005) , and chose to research the case of a service organization for the study and relied on four dimensions of coordination , cooperation , sharing of information , the performance of the team, and was a curriculum approach and des
... Show MoreAbstract
Purpose of this study is to investigate the relationship between Advertising Appeals, Attitudes toward Advertising, and Consumer Buying Behavior for Smart Phone The study was carried out on the students of Middle East University (MEU) In Amman- Jordan. A measurement scales with acceptable reliability and validity is developed to capture the dimensions of study variables. Four hypotheses were tested using Statistical package (SPSS-17). A two-step detailed statistical analysis of data was involved. First, descriptive statistics was performed to understand the underlying components of study variables; second, regression analysis and Path analysis using AMOS 7 were performed t
... Show MoreThe dynamic thermomechanical properties, sealing ability, and voids formation of an experimental obturation hydroxyapatite-reinforced polyethylene (HA/PE) composite/carrier system were investigated and compared with those of a commercial system [GuttaCore (GC)]. The HA/PE system was specifically designed using a melt-extrusion process. The viscoelastic properties of HA/PE were determined using a dynamic thermomechanical analyser. Human single-rooted teeth were endodontically instrumented and obturated using HA/PE or GC systems, and then sealing ability was assessed using a fluid filtration system. In addition, micro-computed tomography (μCT) was used to quantify apparent voids within the root-canal space. The data were statistically analys
... Show MoreFrom the sustainability point of view a combination of using water absorption polymer balls in concrete mix produce from Portland limestone cement (IL) is worth to be perceived. Compressive strength and drying shrinkage behavior for the mixes of concrete prepared by Ordinary Portland Cement (O.P.C) and Portland limestone cement (IL) were investigated in this research. Water absorbent polymer balls (WAPB) are innovative module in producing building materials due to the internal curing which eliminates autogenous shrinkage, enhances the strength at early age, improve the durability, give higher compressive strength at early age, and reduce the effect of insufficient external curing. Polymer balls (WAPB) had been used in the mixes of thi
... Show More