The influence and hazard of fire flame are one of the most important parameters that affecting the durability and strength of structural members. This research studied the influence of fire flame on the behavior of reinforced concrete beams affected by repeated load. Nine self- compacted reinforced concrete beams were castellated, all have the same geometric layout (0.15x0.15x1.00) m, reinforcement details and compressive strength (50 Mpa). To estimate the effect of fire flame disaster, four temperatures were adopted (200, 300, 400 and 500) oC and two method of cooling were used (graduated and sudden). In the first cooling method, graduated, the tested beams were leaved to cool in air while in the second method, sudden, water splash was used to reduce the temperature. Eight of the tested beams were divided in to four groups, each were burned to one of the adopted temperature for about half an hour and cooled by the adopted cooling methods (one by sudden cooling and the other by graduated cooling). After burning and cooling the beams were tested under the effect of repeated load (loading – unloading) for five cycle and then up to failure. As a compared with the non- burned beam, the results indicated that the ultimate load capacity of the tested beams were reduced by (16, 23, 54 and 71)% after being burned to (200, 300, 400 and 500) oC , respectively, for a case of sudden cooling and by (8, 14, 36 and 64)% , respectively, for a case of graduated cooling. It was also found that the effect of sudden cooling was greater than that in a case of graduated cooling. Regarding the failure mode, there was a different between the non-burred beam and the other ones even that all of them had the same geometric layout, compressive strength and reinforcement details. The failure mode for all burned beams was combined shear- flexure failure which was belong to the reduction in the compressive strength of the concrete due to the effect of the temperature rising , while the failure mode of the non-burned beam was flexure failure which was compatible with the preliminary design. It was also detected that the residual deflection proportion directly with the temperature, as the temperature increase to (200, 300, 400 and 500) oC the residual deflection compared with the non-burned beam increased by (32, 48, 326 and 358)% for a case of sudden cooling and by (13, 29, 303 and 332)% for a case of graduated cooling. Another effect was appear represented by the method of cooling, the results showed that the sudden cooling had more effect on the residual deflection than the graduated cooling by (15-6)% approximately. To vanish the residual deflection, numbers of cycle (loading-unloading) were required. It was found that this number increase as the temperature of burning increased and it’s also larger in a case of sudden cooling.
Abstract
The aim of the study is to study the relationship between strategic orientation and organizational performance. The strategic direction is the main purpose for which the organization is found. Therefore, it is the main engine for all the activities and tasks that the institution can carry out to achieve its objectives within the environment in which it operates. ,. The research problem was formed by several questions to determine the level of the strategic direction and the nature of its relationship with organizational performance in the Iraqi Ministry of Defense / Inspector General's Office as the field of application to answer. The sample was selected by a sample of 60 individuals, department managers, And the que
Lately great interests have emerged to find educational alternatives to teach and improve motor skills according to modern educational methods that take into account individual differences and speed in learning for the learner through individual learning that the learner adopts by teaching himself by passing through various educational situations to acquire skills and information in the way he is The learner is the focus of the educational process and among these alternatives the interactive video, the researchers noted through the educational training units at the Model Squash School of the Central Union, and that most of the methods and methods used in learning basic skills take a lot of time in the educational program and do not involve
... Show MoreTen blue swimming crabs Portunus segnis (Forskål, 1775) were collected from the north west of the Arabian Gulf off the Iraqi marine waters from October to November 2017 at 29ᵒ 37′ N to 48ᵒ 47′ E.
The barnacle Octolasmis angulata (Aurivillius, 1894) was found on the gills of the present species of crab, the mean incidence of infestation was 30%, while the mean Intensity of infestation was 12.3. The barnacle have a long and slim shaped calcareous plate with the presence of carina and the absence of tergum, in addition to the elongated shape of carina and scutum. The current study represents the first record of the barnacle O. angulata in the Ar
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Since cancer is becoming a leading cause of death worldwide, efforts should be concentrated on understanding its underlying biological alterations that would be utilized in disease management, especially prevention strategies. Within this context, multiple bodies of evidence have highlighted leptin’s practical and promising role, a peptide hormone extracted from adipose and fatty tissues with other adipokines, in promoting the proliferation, migration, and metastatic invasion of breast carcinoma cells. Excessive blood leptin levels and hyperleptinemia increase body fat content and stimulate appetite. Also, high leptin level is believed to be associated with several conditions, including overeating, emotional stress, inflammation, obesity,
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The research problem lies in identifying the challenges facing spreading the culture of peace in Iraq, and the most important factors of its instability from the point of view of leaders and intellectual elites.The research derives its importance from the fact that the peace imposed by justice leads to a stable Iraq and a prosperous future.
The study aims to identify the most prominent challenges and obstacles created by wars and faced the process of spreading the culture of peace and instability in Iraq, and to shed light on the reasons leading to the employment of the capabilities of community leaders in spreading the culture of peace.The objective of the current research is to identify the challenges of spreading the culture o
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In the current study, wild land plant specimens were collected during the flowering and fruiting period of these plants in February, April, June, August, and October 2023 from the riparian area of the Dujail River, Salahaldin Province, north of Baghdad, Iraq. Identified and the results showed that the number of these species were: 104 species, belong to 29 plant families, Included 26 dicotyledon families with 76 genera and 96 species. The asteraceae family was the most diverse, with 30 species, followed by Brassicaceae with (12) species. Additionally, there were 13 families represented by only one species in Dujail River which included: Apocynaceae, Berberidaceae, Capparaceae, Caryophyllaceae, Convolvulaceae, Geraniaceae, Lythraceae
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Introduction: This study was designed to examine the effects of addition of the combination of polymerized polymethyl methacrylate (PMMA) and zirconia (ZrO2) particles to heat cure PMMA resin on impact strength, surface hardness, and roughness. Methods: The 70% (w/w) of polymerized PMMA powder (particle size: 0.70mm) was mixed with 30% (w/w) of zirconia powder (ZrO2) (1mm) to produce PMMA-ZrO2 filler. Ninety acrylic specimens created were divided into three groups containing 0% wt (Control group), 2% wt, and 4% wt, PMMA-ZrO2 filler. Ten specimens were used for impact strength, surface hardness and roughness test, blindly. Data were analyzed via oneway ANOVA and the Tukey post hoc test using R 3.6.3. Results: There was statistically signific
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