Straight tendons in pretensioned members can cause high-tensile stresses in the concrete extreme fibers at end sections because of the absence of the bending stresses due to self-weight and superimposed loads and the dominance of the moment due to prestressing force alone. Accordingly, the concrete tensile stresses at the ends of a member prestressed with straight tendons may limit the service load capacity of the member. It is therefore important to establish limiting zone in the concrete section within which the prestressing force can be applied without causing tension in the extreme concrete fibers. Two practical methods are available to reduce the stresses at the end sections due to the prestressing force. The first method based on changing the eccentricity of some tendons by raising them towards the end zone. The second method is based on bond prevention by encasing some of the tendons in plastic sheathing, effectively moving the point of application of prestressing force inward toward midspan for part of tendons. The present study focuses on a proposed third method to reduce the effect of the prestressing force near end supports by using straight strands with limited initial prestressing value in compression zone. New equations were suggested for the cracking moment and the prestressing force which consider the prestressed tendons in compression zone.
The experiment was conducted at the plant tissue culture laboratory of the Department of Horticulture and Garden Engineering College of Agricultural Engineering Sciences, University of Baghdad, in order to study the effect of some growth regulators on propagation an stimulation production of volatile oil compounds of rosemary plant Rosmarinus officinlis using two vegetative parts (apical and lateral buds). Factorial experiment was implemented in completely randomized design with twenty replications. The results indicated that culturing the apical meristem on the medium Murashige and Skoog (MS) media with 0.5 mg.l-1 (BA) with 0.1 mg.l-1 of NAA gave the highest response rate of 100%. As for the doubling stage, the levels of BAA and IAA (Indol
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The current research aims to identify the effect of using a model of generative learning in the achievement of first-middle students of chemical concepts in science. The researcher adopted the null hypothesis, which is there is no statistically significant difference at the level (0.05) between the mean scores of the experimental group who study using the generative learning model and the average scores of the control group who study using the traditional method in the chemical concepts achievement test. The research consisted of (200) students of the first intermediate at Al-Farqadin Intermediate School for Boys affiliated with the Directorate of General Education in Baghdad Governorate / Al-Karkh 3 wit
... Show MoreThe rent is one of the sources of investment that generates returns for the owner of the housing unit, and it is also one of the importance expenditure for the tenant.
The importance of this research comes in addressing the deficiency in the field of analyzing the factors affecting the rental value of residential units, which affects many segments of the population of Baghdad.
The aim of this research is analyze and evaluate related variables on the rent value of residential units in neighbourhood 409 in city of BAGHDAD, which is a hypothesis that: There are a set of variables affecting the rental value, including those related to the internal environment of the dwelling, such as: income level, plot area, building area, n
... Show MoreThe article presents the results of studies of the species composition of phytopathogens of winter soft wheat grain affected by ear fusarium. For the first time, studies were conducted using a complex of electron microscopic, molecular genetics, and mycological methods. The species F. graminearum dominated in all samples (frequency of occurrence 42.8%). The species F. avenaceum (23.3%), F. sporotrichioides and F. equiseti (8.8% each) were noted with high frequency. Next in descending order of frequency of occurrence: F. oxysporum, F. boothii, F. poae, F. proliferatum, F. accumatum, F. incarnatum, F. vorosii, F. tricinctum, F. cerealis, F. sambuticum. For the first time, 7 species were found for the plain zone of the Pre-Caucasus: F.
... Show MoreA novel demountable shear connector for precast steel‐concrete composite bridges is presented. The connector uses high‐strength steel bolts, which are fastened to the top flange of the steel beam with the aid of a special locking nut configuration that prevents slip of bolts within their holes. Moreover, the connector promotes accelerated construction and overcomes typical construction tolerances issues of precast structures. Most importantly, the connector allows bridge disassembly, and therefore, can address different bridge deterioration scenarios with minimum disturbance to traffic flow, i.e. (i) precast deck panels can be rapidly uplifted and replaced; (ii) connectors can be rapidly removed and replaced; and (iii) steel beams can b
... Show MoreSteel Reinforced Concrete (RC) frequently faces durability problems. In certain areas, Glass Fiber-Reinforced Polymer (GFRP) rebars are considered a non-corrodible substitute for steel reinforcement. Elevated temperatures have a significant impact on the mechanical characteristics and the adhesiveness of GFRP rebars to concrete, particularly when the polymeric matrix's glass transition temperature is approached or surpassed. Three simply supported reinforced concrete slabs were considered in the experimental program. Each specimen had identical dimensions of 1500×540×120 mm. For the fire resistance requirements, a 45 mm clear concrete cover and an exception of a 200 mm unexposed (cool) anchor zone at the ends were considered. The
... Show MoreAfter word war ll, the United States of America pursued a policy of containment aimed at preventing the Soviet Union from penetrating into the countries of the world, especially the regions of the Middle East, Therefore, it worked to emphasize the establishment of relations that include various political, economic and even cultural aspects, and focused its policy in his aspect on Turkey due to its geopolitical position. At a time when Turkey was undergoing developments at various levels and a change in govemment policy after the Demccratic Party came to power, which focused in its foreign policy on strengthening reltions with the West in general and the United States America in particular. The US government was the supporter of Democrat
... Show MoreCloud computing represents the most important shift in computing and information technology (IT). However, security and privacy remain the main obstacles to its widespread adoption. In this research we will review the security and privacy challenges that affect critical data in cloud computing and identify solutions that are used to address these challenges. Some questions that need answers are: (a) User access management, (b) Protect privacy of sensitive data, (c) Identity anonymity to protect the Identity of user and data file. To answer these questions, a systematic literature review was conducted and structured interview with several security experts working on cloud computing security to investigate the main objectives of propo
... Show MoreThe main idea of the financial censorship is to submit the states funds to a censorship because they are the funds of the people and because this censorship is a right and role ensured by the constitution for specific devices in the state, thus the role of the financial censor should be launched to achieve this goal in all walks of the state. • The power of this censorship depends basically on the independence of the censorious bodies over a job which is submitted to this censorship and the censor should have a reverence , this censorship is practiced as a precautionary procedure before preparing the budget to avoid mistakes after and during the execution for maintaining the states funds. • The importance of the censorship comes from
... Show MorePraise be to God, who started his book with the praise of himself and prayers and peace be upon those who have no prophet after him and his family and companions and those who followed them with charity until the Day of Judgment.
For it is known to every researcher in jurisprudence and its origins that the semantics in terms of formulas for assignment are divided into an order and a prohibition, and I have seen it necessary to write a small research on the prohibition, and since this topic is complex, and has a great impact on the difference of scholars, I decided to write on one issue of it And it is the absolute prohibition and its effect on the difference of jurists, and what is meant by the absolute p