Several stress-strain models were used to predict the strengths of steel fiber reinforced concrete, which are distinctive of the material. However, insufficient research has been done on the influence of hybrid fiber combinations (comprising two or more distinct fibers) on the characteristics of concrete. For this reason, the researchers conducted an experimental program to determine the stress-strain relationship of 30 concrete samples reinforced with two distinct fibers (a hybrid of polyvinyl alcohol and steel fibers), with compressive strengths ranging from 40 to 120 MPa. A total of 80% of the experimental results were used to develop a new empirical stress-strain model, which was accomplished through the application of the particle swarm optimization (PSO) technique. It was discovered in this investigation that the new stress-strain model predictions are consistent with the remaining 20% of the experimental stress-strain curves obtained. Case studies of hybrid–fiber–reinforced concrete constructions were investigated in order to better understand the behavior of such elements. The data revealed that the proposed model has the highest absolute relative error (ARE) frequencies (ARE 10%) and the lowest absolute relative error (ARE > 15%) frequencies (ARE > 15%).
Several studies have indicated that more than 600 cities in the world (intermas of rapid growth and development) will generate about 60% of international economic growth between 2010 and 2025 . by 2025 , 66% of the worlds population will live in urban areas the management of cities will face challenges that accompany this increase in the population which requires preparing to face these challenges and problems and the need to provide the aim of the research to know the readiness of Baghdad city to implement the strategies of urban management throught on asmple representing the ( Advisiry group for the comprechnsive development plan for the city of Baghdad 2030 and its supporters ) in the municipality of Baghdad and the number of
... Show Morethe political changeable is important reflection in areas of life and the designers tried to high light it in the cover of Journal promised time Journal a fertile square to show reflection of political changeable, and triad to search the current path. The first chapter organized according to axes, problem of research formulated according to question:- what are reflections of political changeable in magazine cover?
The importance of research depth of specialized approach on level of technical and stylistic as ago al ago as in: the baring of political changeable in design of journal's cover. The research moves in cognitive border from 2013 to 2017 and selection of t
... Show MoreThe purpose of the present study is to identify the comprehensive concept of desertion through the Holy Qur’an and to derive some educational implications related to the concept of desertion and its editing. The also aims to explain the images and forms of desertion. The researcher used the qualitative analytical method. The study concluded that the comprehensive concept of desertion was represented in moving from the country of polytheism to the country of Islam, singularity, alienation, and isolation, leaving, repelling and showing off, abandoning the wife in bed, and reciting from the Qur’an recitation, action, and arbitration, insulting, abandoning, delirium, intersection, and manipulation. The researcher has drawn many education
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The paper is concerned with, the behavior of the hydrostatic thrust bearings lubricated with liquid-solid lubricants using Einstein viscosity formula, and taking into account the centrifugal force resulting from high speed. Also studied is the effect of the bearing dimensions on the pressure, flow rate, load capacity, shear stress, power consumption and stiffness.
The theoretical results show an increase in load capacity by (8.3%) in the presence of solid graphite particles with concentration of (16%) by weight as compared with pure oil, with increasing shear stress. .
In general the performance of hydrostatic thrust bearings improve for load carrying capacity, volume flow rate,
... Show MoreIn this paper, a new approach was suggested to the method of Gauss Seidel through the controlling of equations installation before the beginning of the method in the traditional way. New structure of equations occur after the diagnosis of the variable that causes the fluctuation and the slow extract of the results, then eradicating this variable. This procedure leads to a higher accuracy and less number of steps than the old method. By using the this proposed method, there will be a possibility of solving many of divergent values equations which cannot be solved by the old style.
This research studying the phenomenon of Doppler (frequency Doppler) as a method through which the direction and speed of the blood cells flows in blood vessels wear measured. This Doppler frequency is relied upon in medicine for measuring the speed of blood flow, because the blood flow is an important concept from the concepts of medicine. It represents the function and efficient of the heart and blood vessels in the body so any defect in this function will appear as a change in the speed of blood flow from the normal value assumed. As this speed changes alot in cases of disease and morbidity of the heart, so in order to identify the effect of changing the Doppler frequency on the speed of blood flow and the relationship of
... Show MoreThe Sebkha of geomorphological aspects of evaporative where climate leads active role, which forms part of the earth's surface in the form of Iraqi Mesopotamia plain who of the most fertile land, and because of natural factors and human Common turned most of the arable land to the territory of Sebkha. It was to determine the exact geomorphological associated of Sebkha formats by field work such as: Alnbaka, lakes, salt flats, and other forms of Small is: bridges salt, mud cracks, salt ponds, Rectangles and polygons salt, Sahaf salt, salt domes, salt gravel, bumps saline (salt points), Ash salt, salt bows, in detail and accurately documented Terrestrial Photogrammetry field and were compared to the levels and standards varieties have been
... Show MoreThe research seeks to identify the factors affecting the monopoly and the possibility of measuring the phenomenon of economic ( monopolistic profit) accounted for and that the importance of research topic arising from the transformation of the majority of developing countries to the market economy, which represents the image of the capitalist economy, which is a monopoly, a stages that economy in its various forms, whether Market Worldwide sales monopoly or monopoly, which generates absolute monopolistic profits, which more or less affect on the overall economy of those countries than they should study the phenomenon of monopoly and its impact on the economies of those countries that still love to find her site reinforces its pos
... Show MoreTwilight is that light appear on the horizon before sunrise and after sunset, Astronomically it is known that sunrise and sunset are effected by high above sea level, but the effect of high above sea level on the time of astronomical twilight still not decided and controversy among astronomers, in This research we studies the effect of high above sea level on the time of astronomical twilight, through adding the equation correct high above sea level to equation computation of twilight and then calculate of changing in the time of twilight for different highest (0-10000) meters above sea level , and the ratio of increase for time with high between (15.45-20.5) minutes. It was found that there was an increase in the time of the twilight along
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