A novel welded demountable shear connector for sustainable steel-concrete composite structures is proposed. The proposed connector consists of a grout-filled steel tube bolted to a compatible partially threaded stud, which is welded on a steel section. This connector allows for an easy deconstruction at the end of the service life of a building, promoting the reuse of both the concrete slabs and the steel sections. This paper presents the experimental evaluation of the structural behavior of the proposed connector using a horizontal pushout test arrangement. The effects of various parameters, including the tube thickness, the presence of grout infill, and the concrete slab compressive strength, were assessed. A nonlinear finite element model was also calibrated against the experimental results, and the validated numerical model was used to extend the validity of the experimental results and to perform further parametric studies. The experimental and numerical results show that the tested connectors have similar stiffness, but higher shear resistance and slip capacity compared with traditional welded shear studs and can be classified as ductile according to Eurocode 4.
A charge transfer complex formed by interaction between nitron as electron donor with curcumin(1 ) as electron acceptor in ethanol at the temperature of theroom to form a colored complex. The optimum conditions of complex formation were investigated by Univariate method. The linearity range of complex was (3.124– 53.11) μg.mL-1 at 442 nm with molar absorptivity (1858.33) L.mol-1.cm-1, Sandell's sensitivity (0.1681μg.cm-2), and with a correlation coefficient (0.9935). Both modified attapulgite and modified attapulgite – complex have been characterized by using , FTIR, SEM, AFM, and XRD. Theadsorption behaviourof complex onto the modified attapulgite has been researchedthrough the variation of the parameters like the adsorbent weight, p
... Show MoreOptimization is essentially the art, science and mathematics of choosing the best among a given set of finite or infinite alternatives. Though currently optimization is an interdisciplinary subject cutting through the boundaries of mathematics, economics, engineering, natural sciences, and many other fields of human Endeavour it had its root in antiquity. In modern day language the problem mathematically is as follows - Among all closed curves of a given length find the one that closes maximum area. This is called the Isoperimetric problem. This problem is now mentioned in a regular fashion in any course in the Calculus of Variations. However, most problems of antiquity came from geometry and since there were no general methods to solve suc
... Show MoreBackground: Dental stone casts come into contact with impression materials and becomes susceptible to cross contamination from saliva and blood. This study was done to evaluate the physical and mechanical properties of dental stone type IV after treatments with various disinfecting agents and regimes (methods). Materials and Methods: Type IV dental stone and different types of disinfecting agents were used and divided into seven groups: G1: dental stone without disinfection (control group), G2: dental stone mixed with silver nitrate powder 0.5% , G3: dental stone mixed with silver nitrate powder 1%, G4: dental stone mixed with copper sulfate powder 0.5%, G5: dental stone mixed with copper sulfate powder 1% ,G6: dental stone immersed in prop
... Show MoreA new ligand [N-(4-nitrobenzoylamino)-thioxomethyl] phenylalanine is synthesized by reaction of 4-nitrobenzoyl isothiocyanate with phenylalanine (1:1). It is characterized by micro elemental analysis (C.H.N.S.), FT-IR, (UV-Vis) and 1H and 13CNMR spectra. Some metals ions complexes of this ligand were prepared and characterized by FT-IR, UV-Visible spectra, conductivity measurements, magnetic susceptibility and atomic absorption. From results obtained, the following formula [M(NBA)2] where M2+ = Mn, Co, Ni, Cu, Zn, Pd, Cd and Hg, the proposed molecular structure for these complexes as tetrahedral geometry, except copper and palladium complexes are have square planer geometry.
In this work, 332 Al alloy was prepared and reinforced with (0.5% and 1%) nano-Al2O3 particles. The prepared unreinforced and reinforced 332 Al alloy with nano-Al2O3 were solution heat treated (T6) at 510 ̊C and aged at 225 ̊C with different times (1, 3, and 5 h). Hardness test was performed on all the prepared alloys. All prepared alloys were dry slided under different applied loads (5, 10, 15, and 20 N) against steel counterface surface using pin on disk apparatus. The results showed that refinement effect was observed after addition of nano-Al2O3 particles and a change in silicon morphology after performing the solution heat treatment. The results also showed that har
... Show MoreThe current study was designed to investigate the presence of aflatoxin M1 in 25 samples of pasteurized canned milk which collected randomly from some Iraqi local markets using ELISA technique. Aflatoxin M1 was present in 21 samples, the concentration of aflatoxin M1 ranged from (0.25-50 ppb). UV radiation (365nm wave length) was used for detoxification of aflatoxin M1 (sample with highest concentration /50 ppb of aflatoxin M1 in two different volumes ((25 & 50 ml)) for two different time (15 & 30 min) and 30, 60, 90 cm distance between lamp and milk layer were used for this purpose). Results showed that distance between lamp and milk layer was the most effective parameter in reduction of aflatoxin M1, and whenever the distance increase the
... Show MoreMeaning letters in Arabic are characterized by the diversity and abundance of their linguistic material, and are also distinguished by their large number and types, to the point that some of them have reached a hundred letters confined to five categories
Background/Aim: Knee osteoarthritis is a frequently crippling chronic condition. Numerous pharmacological medications have been successfully utilised to treat knee osteoarthritis. This research aimed to compare the efficiency of metformin and serratiopeptidase in treating and preventing osteoarthritis development via distinct mechanisms. Methods: Between 1 January and 30 May 2019, a randomised-clinical-trial was done at Al-Kindy Hospital on 80 osteoarthritis patients, divided in two groups. Group I was given metformin 850 mg orally, whereas Group II was given serratiopeptidase 20 mg and metformin 850 mg orally. Parameters in these groups were compared with forty healthy normal controls. Results: Following treatment, patients in Grou
... Show MoreDetermination of the level of adipokines (obestatin, vaspin, tumor necrosis factor-? and interleukin-6)in hypo-and hyperthyroid patients from Educational Baghdad Hospital in Baghdad City was investigated. Fifty patients with hypothyroidism and Fifty patients with hyperthyroidism were selected. A control group of thirty euthyroid persons was included. Blood was collected by vein puncture and serum was separated and stored at –20C. Adipokines (obestatin, vaspin, tumor necrosis factor-? and interleukin-6) were estimated using ELISA method. The findings show a significant (p<0.05) increase in obestatin level in hypothyroid patients, while there is no significant difference in hyperthyroid patientsas compared with the euthyroid subjects.
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