A steel-concrete composite structure (1) is described. The steel-concrete composite structure comprises a steel member (2) having an upper surface (5) and a plurality of shear connector elements (6) upstanding from the upper surface and a concrete slab (4) having upper and lower surfaces (7, 8). The slab is supported on its lower surface by the upper surface of the steel member. The slab comprises a plurality of through holes (9) between the upper and lower surfaces, each through hole tapering towards the lower surface so as to form an inverted frustally-shaped seating surface (10). The concrete slab is configured and positioned with respect to the steel member such that at least one shear connector element projects into each through hole. The steel-concrete composite structure comprises a plurality of removable inverted frustoconical plugs (15), each plug having top and bottom surfaces (18, 19; Fig. 6) and an inverted frustoconically-shaped plugging surface (20; Fig. 6). Each plug has at least one through hole (16) between the top and bottom surfaces. At least one plug (15) is seated in a corresponding through hole (9) of the concrete slab. Each plug is configured such that at least one of the least one shear connector elements (6) projecting into the corresponding through hole (9) is received by a corresponding though hole (16) of the plug. The structure also comprises a plurality of fasteners (17, 29), each fastener coupled to a corresponding shear connector element and arranged to discourage removal of a plug (15) from a through hole (9) of the concrete slab.
The inhibitor property of curcuma longa L. extract in different concentrations of simulated refinery wastewater (0.05% - 2% wt) and at various temperatures (30, 35 and 40 ˚C) was investigated using weight loss method. The results showed that the presence of about 1.2 % (v/v) of curcuma extract gave about 84% inhibition indicating its effectiveness on mild steel corrosion in simulated refinery wastewater, besides the adsorption process on the mild steal surface obeyed the Langmuir adsorption isotherm.
Phenylthiourea (PHTU),was tested as inhibitor for the corrosion of low carbon steel in different HCI acid concentration by mass loss ,and polarization measurements .it was found that (PHTU) is a good inhibitor for the corrosion of low carbon steel in 1,3,and 5N HCI solution ,and its inhibition efficiency (0) increases with its concentration and attains approximately 97% at l g/I .polarization curves indicate that (PHTU) acts as an anodic type inhibitor .the inhibitor was adsorbed on the low carbon steel surface according to the Langmuir adsorption isotherm model. Results show that the rate of corrosion of low carbon steel increased with increasing temperature o
... Show MoreThe effects of shot peening treatment (SPT) were studied at (10,20, and 30) minutes on the rotating bending fatigue behavior and the behavior of the alloy steel DIN 41Cr4 vibrations. The hardness test, tensile test, constant amplitude fatigue tests, and the vibration measurements were performed on samples with and without cracks at room temperature (RT), also, the fracture surface was examined and analyzed by a Scanning Electron Microscope (SEM). The results of the investigations, for example, Stress to Number of cycles to failure (S-N) curves, fatigue strength improvement factor of 5% to 10%, the decreasing percentage of maximum Fast Fourier Transform (FFT) acceleration of the shot-peened condition were compared to untr
... Show MoreIn this paper, Response Surface Method (RSM) is utilized to carry out an investigation of the impact of input parameters: electrode type (E.T.) [Gr, Cu and CuW], pulse duration of current (Ip), pulse duration on time (Ton), and pulse duration off time (Toff) on the surface finish in EDM operation. To approximate and concentrate the suggested second- order regression model is generally accepted for Surface Roughness Ra, a Central Composite Design (CCD) is utilized for evaluating the model constant coefficients of the input parameters on Surface Roughness (Ra). Examinations were performed on AISI D2 tool steel. The important coefficients are gotten by achieving successfully an Analysis of V
... Show MoreIn this research, (MOORA) approach based– Taguchi design was used to convert the multi-performance problem into a single-performance problem for nine experiments which built (Taguchi (L9) orthogonal array) for carburization operation. The main variables that had a great effect on carburizing operation are carburization temperature (oC), carburization time (hrs.) and tempering temperature (oC). This study was also focused on calculating the amount of carbon penetration, the value of hardness and optimal values obtained during the optimization by Taguchi approach and MOORA method for multiple parameters. In this study, the carburization process was done in temperature between (850 to 950 ᵒC) for 2 to 6
... Show MoreThis paper reports an experimental study of welding of dissimilar materials between transparent Polymethylmethacrylate (PMMA) and stainless steel 304 sheets using a pulsed mode Nd:YAG laser. The process was carried out for two cases; laser transmission joining (LTJ) and conduction joining (CJ). The former is achieved when the joint is irradiated from the polymer side and the latter when the joint is irradiated from the opposite side (metal side). The light and process parameters represented by the peak power (Pp), pulse duration (τ), pulse repetition rate (PRR), scanning speed (ν) and pulse shape have a significant effect on the joint strength (Fb), joint bead width (b), joint quality and appearance. The optimum parameters were determined
... Show MoreThe study focused on the results of first paleostress from thrust fault slip data on Tertiary age of Hemrin North Structure, North of Iraq. The stress inversion was performed for fault slip data using an improved right dihedral model, and then followed by rotational optimization (Georient Software). The trend of the principal stress axes (σ1, σ2 and σ3) and the ratio of the principal stress differences (R) show the main paleostress field is NE-SW compression regime. As well as using Lisle graph and Mohr diagram to determine the magnitudes of palestress. The values paleostress of the study area were σ1=1430 bars, σ2=632 bars and σ3=166 bar. The large magnitudes of the primary stress axes could be attributed to active tecto
... Show MoreThe histological structure of Pycnonotus leucotis was investigated to fill the dearth of information on the histology of mid-brain from available literature and help understand its brain. The brain is wide and short and its length 1.5 cm, and it consists of three regions. The middle region is the mesencephalon. The mesencephalon was divided into optic tectum and tegmentum. The optic tectum consists of six main layers, while the tegmentum contains nuclei of cranial nerves.
The nuclear ground-state structure of some Nickel (58-66Ni) isotopes has been investigated within the framework of the mean field approach using the self-consist Hartree-Fock calculations (HF) including the effective interactions of Skyrme. The Skyrme parameterizations SKM, SKM*, SI, SIII, SKO, SKE, SLY4, SKxs15, SKxs20 and SKxs25 have been utilized with HF method to study the nuclear ground state charge, mass, neutron and proton densities with the corresponding root mean square radii, charge form factors, binding energies and neutron skin thickness. The deduced results led to specifying one set or more of Skyrme parameterizations that used to achieve the best agreement with the available experimental
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