This paper studies the behavior of reinforced Reactive Powder Concrete (RPC) two-way slabs under static and repeated load. The experimental program included testing six simply supported RPC two-way slabs of 1000 mm length, 1000 mm width, and 70 mm thickness. All the tested specimens were identical in their material properties, and reinforcement details except their steel fibers content. They were cast in three pairs, each one had a different steel fibers ratio (0.5 %, 1 %, and 1.5 %) respectively. In each pair, one specimen was tested under static load and the other under five cycles of repeated load (loading-unloading). Static test results revealed that increasing steel fibres volume fraction from 0.5 % to 1 % and from 1% to 1.5%, led to an increase in the: first crack load by (32.2 % and 52.3 %), ultimate load by (36.1 % and 17.0 %), ultimate deflection by (33.6 % and 3.4 %), absorbed energy by (128 % and 20.2 %), and the ultimate strain by (1.1 % and 6.73 %). It also increased the stiffness and the ductility of the specimens especially at the final stages of loading. Additionally, it delayed the propagation of the cracks, controlled their growth, kept the integrity of the specimens at post cracking stage, and avoided their ruin at the failure stage through its “bridging” effect. For the repeated load test, applying five cycles of repeated load to the steel fiber reinforced RPC two-way slab specimens led to a decreasing in the ultimate load capacity, ultimate deflection, ultimate strain, and absorbed energy in a comparison with the corresponding static test specimens, and that because of the loading-unloading process which causes a fluctuation of stresses and more damages in concrete. Increasing the steel fibers volume fractions decreased the dissipated energy of the specimens that subjected to a repeated load, where the difference percent of dissipated energy between the first and second cycles of (R0.5 %, R1 %, and R1.5 %) specimens were (68.0 %, 46.2%, and 32.4%) respectively.
This study revealed the efficiency of Bacillus subtilisin degrading two textile dyes (disperse red and disperse yellow), the rates of red dye removal when measured after 24, 48, 72 and 96 hours for the concentrations of 50 ppm were 51.67, 67.56, 84.67 and 95.33%, for the concentration 150 ppm were 41.67, 62.67, 80.67 and 89.67%, while for the concentration 300 ppm were 25.67, 42.67, 71.67 and 84.33%. The results of yellow dye removal showed that the concentration of 50 ppm were 49.67, 65.33, 83.33 and 92.67%, for the concentration of 150 ppm were 38.33, 60.33, 77.33 and 87.33%, and for the concentration, 300 ppm were 24, 36.67, 68.33 and 81.67%, when measured after 24, 48, 72 and 96 hours. Results recorded a slight decrease in pH valu
... Show MoreThis study, establishes two stochastic monotonicity results concerning the run length of an upper one –sided Exponentially Weighted Moving Average (EWMA) control charts, based on the logarithm of the sample variance, for monitoring a process standard deviation, these properties cast interesting light on the control chart performance, and their extension to other one –sided EWMA control charts.
Examination of 241 specimens of two bee-eater species, Merops apiaster and Merops
superciliosus persicus reveal recording of Haemoproteus meropis (Zagar, 1945) emend.
Bennett, 1978 and H. manwelli Bennett, 1978 for the first time in Iraq. A new species
Haemoproteus hudaidensis sp. nov. is described. Microfilariae are also infected the two host
species. The results are discussed with the pertinent literature and the necessary comparision
of morphometric measurements of the recorded parasites with that previously reported is
provided along with a taxonomic key including the newly described haemoproteid.
This study was conducted in the poultry field of the Department of Animal Production/ College of Agricultural Engineering Sciences / University of Baghdad for the period from 42 days. Aiming to know the effect of using shrimp waste powder (Metapenaeus Affinis) and enzyme in broilers diet on physiological and microbial performance and indicators of fat oxidation in meat. 250 one-day-old ROSS308 chicks were used. The chicks were fed on diets containing shrimp waste treated with enzyme and not treated with protease enzyme by 0,4,6 %. The experiment included five treatments, with 5 replicates for each treatment, and each replicate contained 10 birds. The results showed a significant decrease (P≤0.05) in the concentration of ALT and AS
... Show MoreOne of the important goals in the learning process is to be effective learning through the self-direction of the learner , because it has an impact on the effort of learners , it is better to be a learner responsible for learning and independent of the acquisition of knowledge ,
اذ اكدتكثيرAs many have confirmed منFrom الدراساتStudies والادبياتAnd literature انthat فشلالكثير The failure of many منFrom الطلبةStudents فيin a تنظيمgroup المعلوماتthe information ومعالجتهاAnd processed اثناءduring عمليةProcess تعلمهمLearn them لاNo يرجعReturns الىto me انخفاضdrop فيin a درجةDegree ذكائهمTheir intelligence اوor عدمNo
... Show MoreTwo Prototypes of Transversely Excited at atmospheric pressure (TEA) Nitrogen laser systems (One Stage Blumlein Circuit and Two Stage Blumlein Circuit) were fabricated and operated. High voltage power supply with variable operating voltage (0-20 kv) and operating current (1-3A) was built and tested successfully. The gas flow rate of 15 L/ min and 10 L/ min for OSBC and TSBC was used. The performance of the fabricated systems was studied extensively reaching to the optimum operating conditions. The obtained laser output energy for the first system has linear relationship with the applied voltage. The maximum output energy was about (1.14 mJ) with (10.40) ns pulse duration and the half-wave divergence angle was about (0.1455 m rad). In the
... Show MoreIn this study, the effect of the combination of micro steel fibers and additives (calcium hydroxide and sodium carbonate) on the size of cracks formation and healing them were investigated. This study aims to apply the use of self-healing phenomenon to repair cracks and to enhance the service life of the concrete structures. Micro steel fibers straight type were used in this research with 0.2% and 0.4% by volume of concrete. A weight of 20 and 30 kg/m3 of Ca(OH)2 and 2 and 3 kg/m3 of Na2CO3 were used as a partial cement replacement. The results confirm that the concrete cracks were significantly self-healed up to 30 days re-curing. Cracks width up to 0.2 mm were comp
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The bourgeoisie groups derived great advantages from the system upon which the Fatimids built up their Regime out the land-tax and other taxes against a fixed sum . The surpulus revenue was the prophet of the farmers . A striking feature of the Fatimid was freedom of enterprise .All sectors of economic life were free-crafts , industry and trade . The government interfered in the trade in victuals only so far to in order to guarantee the supply of wheat to the big towns
The Egyptian Bourgeoisie enjoyed also the great prosperity which was produced among other reasons by the inflationary system of Fatimid economy .
The maintenance of gold dinar being almost pure and of full weight was only possible because Egypt steadily received cons
