Two novel demountable shear connectors for precast steel-concrete composite bridges are presented. The connectors use high-strength steel bolts, which are fastened to the steel beam with the aid of a special locking configuration that prevents slip of bolts within their holes. Moreover, the connectors promote accelerated construction and overcome typical construction tolerances issues of precast structures. Most importantly, the connectors allow bridge disassembly, and therefore, can address different bridge deterioration scenarios with minimum disturbance to traffic flow, i.e. (1) precast deck panels can be rapidly uplifted and replaced; (2) connectors can be rapidly removed and replaced; and (3) steel beams can be replaced, while precast decks and shear connectors can be reused. A series of push-out tests and a beam test were conducted to assess the behavior of the connectors and quantify the effect of important parameters. The experimental results showed that shear resistance and slip capacity can reach 2.5 and 2.7 times respectively of those of welded shear studs along with superior stiffness and strength against slab uplift. Additionally, shear stiffness of M16 mm LNSC was equal to that of M19 mm welded studs. Identical tests reveal negligible scatter in the shear load – slip displacement behavior. Design equations are proposed to predict the shear resistance with minimum deviations.
Supervised By : Prof. dr. Shaker Jaseem Mohammed This research aims to identify the (effectiveness of Bayer's strategy in the development of deductive thinking among students in the fifth grade literary material European history) and to achieve the goal set researcher null hypothesis of the following: • There is no statistically significant difference between the average scores of the experimental group which studied the use of Bayer's strategy and the control group, which studied the use of the usual way in the development of deductive reasoning. The study sample consisted of (84 students) of the students in the fifth grade literary breeding Baghdad / Karkh second Directorate for the academic year 2015-2016 were distributed Aanhaldras
... Show MoreThe purpose of this research is to identify the effect of the use of project-based learning in the development of intensive reading skills at middle school students. The experimental design was chosen from one group to suit the nature of the research and its objectives. The research group consisted of 35 students. For the purpose of the research, the following materials and tools were prepared: (List of intensive reading skills, intensive reading skills test, teacher's guide, student book). The results of the study showed that there were statistically significant differences at (0.05) in favor of the post-test performance of intensive reading skills. The statistical analysis also showed that the project-based learning approach has a high
... Show Morethe reality of small and medium enterprises analysis reflects weaknesses plaguing these enterprises and strengths that are characterized by, and thus the formulation of appropriate solutions to the obstacles faced by these enterprises to enhance its contribution to the achievement of economic and social development. Iraqi small and medium enterprises suffer from several obstacles stand in front of development and support their competitiveness, the finance one of the main obstacles which impede growth and development of these enterprises, noting the banking system in Iraq reluctance to lend to small and medium-sized enterprises, as a result of the high cost of lending these enterprises compared to large projects, as well as
... Show MoreEducation in it s different levels becomes development in any country. There fore, nations pay great attention to educational systems, because they perceive that preparing human resources is essential to the development of these nations.
The present study deals with the a academic frames which formulate education in each educational system such as educational philosophy , educational aims , educational strategies by which the academic frames are carried out, which is limited to curriculum, teacher preparations, school activities, in addition to guidance and counseling.
This study reaches some conclusion which are derived from the description of the academic and practical frames some suggestion are made for the mechanism which facil
The study highlighted the transformation of value systems and educational patterns between past and present, especially with the introduction of modern variables and means, such as mobile phones, the internet, social media, and others. These factors have contributed both positively and negatively to the study. The study highlights the integral role of the school in collaboration with the family in guiding and educating children. It also emphasizes the active role of the school in developing students' abilities and skills, either attracting them to school or vice versa. This includes an examination of the essential skills required in education and their role in achieving a state of psychological well-being and systematically developing child
... Show MoreMany economists believe that the development and promotion of small and medium-sized enterprises is one of the most important sources of economic and social development in countries in general and in developing countries in particular. This is considered to be an essential starting point for increasing production capacity and contributing to tackling poverty and unemployment. In view of the importance of these projects, most developing countries have concentrated their efforts on them. They have encouraged the establishment of small and medium industries, especially after they have proved their ability and efficiency in dealing with the major problems facing different economies.
The banking system plays an important role by finan
... Show MoreAbstract: The researcher aims to highlight the historical frames of political development in royal regime era (1921-1949) and study its transitions on social-political aspect for the various periods during this consistent era of Iraq history. As some elements played an important role in shaping this era’s features ,as well as 2hat succeed it, which mainly affected the political progression’s configuration, such as : political culture role, social and cultural foundation, state policy essence and the unofficial institutions remarkable role in influencing public awareness and concerning it's relation to the state ,the clan and religious institutions. The researcher employed Alexis de Tocqueville’s evaluation criteria and indi
... Show MoreA theoretical and protection study was conducted of the corrosion behavior of carbon steel surface with different concentrations of the derivative (Quinolin-2-one), namely 7-Ethyl-4-methyl-1-[(4-nitro-benzylidene)-amino]-1H-quinolin-2-one (EMNQ2O). Theoretically, Density Functional Theory (DFT) of B3LYP/ 6-311++G/ 2d, 2p level was carried out to calculate the geometrical structure, physical properties and chemical inhibition chemical parameters, with the local reactivity in order to predict both the reactive centers and to know the possible sites of nucleophilic and electrophilic attacks, in vacuum and two solvents (DMSO and H2O), all at the equilibrium geometry. Experimentally, the inhibition efficiencies (%IE) in (3.5% NaCl)
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