A ‘locking-bolt’ demountable shear connector (LBDSC) is proposed to facilitate the deconstruction and reuse of steel-concrete composite structures, in line with achieving a more sustainable construction design paradigm. The LBDSC is comprised of a grout-filled steel tube and a geometrically compatible partially threaded bolt. The latter has a geometry that ‘locks’ the bolt in compatible holes predrilled on the steel flange and eliminates initial slip and construction tolerance issues. The structural behaviour of the LBDSC is evaluated through nine pushout tests using a horizontal test setup. The effects of the tube thickness, strength of concrete slab, and strength of infilled grout on the shear resistance, initial stiffness, and ductility of the LBDSC are assessed. The experimental results show that the LBDSC can achieve higher shear resistance and similar initial stiffness as compared to traditional welded studs. In addition, all tested LBDSCs exhibited slip capacities ranging from 14 to 32 mm and can be classified as ductile shear connectors according to Eurocode 4. A detailed finite element model was also created and found to be reliable to reproduce the experimental behaviour. Parametric studies were subsequently conducted using the validated model to study further parameters and generalise the experimental results. Due to the specific test setup, non-negligible uplift forces were generated in the connector and the potential implications are discussed.
This study aims to find out the effect of the mediator on scaffolding fourth yearstudent- teachers' teaching competencies and their self-efficacy. The present study combines scaffolding and self-efficacy by using a mediator on scaffolding students affects teaching competencies and selfefficacy and from the results of which the existence of student-teachers’ selfawareness was ensured as an effect of the same independent variable. The model affects their teaching competencies and led them to be aware of the needs of their pupils and themselves.
In this work magnetite/geopolymer composite (MGP) were synthesized using a chemical co-precipitation technique. The synthesized materials were characterized using several techniques such as: “X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), vibrating sample-magnetometer (VSM), field-emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), Brunauer–Emmett–Teller (BET) and Barrentt-Joyner-Halenda (BJH)” to determine the structure and morphology of the obtained material. The analysis indicated that metal oxide predominantly appeared at the shape of the spinel structure of magnetite, and that the presence of nano-magnetite had a substantial impact on the surface area and pore st
... Show MoreIn this study, a one-dimensional model represented by Butler-Volmer-Monod (BVM) model was proposed to compute the anode overpotential and current density in a mediator-less MFC system. The system was fueled with various organic loadings of real field petroleum refinery oily sludge to optimize the favorable organic loading for biomass to operate the suggested system. The increase in each organic loading showed higher resistance to electrons transport to the anode represented by ohmic loss. On the contrary, both activation and mass transfer losses exhibited a noticeable decrement upon the increased organic loadings. However, current density was improved throughout all increased loads achieving a maximum current density of 5.2 A/m3
... Show MoreThe Love Creek Nature Center, one of the three nature centers located within the boundaries of Berrien County, is owned and operated by the county for public enjoyment and instruction of nature. The 44.5 ha study area, located seven km east of Berrien Springs, and two km southwest of Berrien Center, on Huckleberry Road, in T6S, R17W, sections 16, 17 (Lat. 41° 56' N; Long. 86° 18' W) is made up of deciduous woods and abandoned fields at various stages of succession. It is bounded on the east by the Berrien County Dog Pound and Huckleberry Road, to the north by cultivated Berrien County land and the Berrien General Hospital, to the west by the recently closed Berrien - Oronoko Township Landfill Dump; and to the south b
... Show MoreAcinetobacter baumannii (A. baumannii) is a major opportunistic nosocomial pathogen, mostly resistant to several groups of antibiotics. Colistin is now used as a last-line treatment for isolates that are highly resistant. The purpose of this study is to identify the importance of LptD; which is involved in the translocation of LPS from the inner membrane to the outer membrane in compartment with LptA and LptC of A. baumannii and its indispensable role as a virulence factor, and the efficiency of colistin as a monotherapy. In the current research, two isolates of A.baumannii were used, the local isolate HHR1 isolated from urine sample and the global strain ATCC 17904, and three antibiot
... Show MorePrevious studies in Euro-American countries have shown that patients with chronic hepatitis C virus infection have increased levels of neuropsychiatric symptoms. While chronic hepatitis C virus infection has been reported in Arab countries such as Iraq, there is little studies about the neuropsychological burden associated with chronic hepatitis C among patients in the Arab region. The aim of the current study was to measure the prevalence and level of severity of depression, anxiety and stress among a sample of chronic hepatitis C patients in AL-Najaf province /Iraq. The current study was cross-sectional study carried out on (110) already diagnosed chronic viral hepatitis C patients who attended the Gastroenterology and Hepatology
... Show MoreN-Pyridin-2-ylmethyl-benzene-1,2-diamine (L) was prepared from the reaction of ortho amino phenyl thiol with 2 – amino methyl pyridine in mole ratio (1:1) . It was characterized by elemental analysis (C.H.N) , FT-IR , Uv – Vis , 1H , 13C-N.M.R . The complexes of the bivalent ions (Co , Ni , Cu ,Pd , Cd , Hg and Pb) and the trivalent (Cr) have been prepared and characterized too . The structural was established by elemental analysis (C.H.N) , FT-IR , Uv – Vis spectra , conductivity measurements , atomic absorption and magnetic susceptibility . The complexes showed characteristic behavior of octahedral geometry around the metal ions and the (N,N,N) ligand coordinated in tridentat mode except with Pd complexes sho
... Show MoreBackground: A great dental and biomedical interest had been paid to silver nanoparticles because of their antimicrobial activity. Objective: To evaluate the antimicrobial and cytotoxic activity of a newly developed Nano-silver fluoride that was synthesized from moringa oleifera leaf extract against S. mutants. Material and method: The green synthesis method was used to prepare Nano-silver fluoride from moringa oleifera leaf extract. The minimum inhibitory concentration and the minimum bactericidal concentration were evaluated using brain heart infusion plates, while the cytotoxicity was evaluated by the hemolytic activity. Results: Nano-silver fluoride had a bactericidal and bacteriostatic effect (MIC was 60 ppm and MBC was 120 pp
... Show MoreThis paper introduces a complete design and simulation of a controller for the double fed induction generator (DFIG) turbine. The work also included the solar updraft tower (SUT) design to supply Al-Mahmoudia hospital in Baghdad/Iraq. The design includes the daily average load estimation, annual solar irradiance and, temperature monitoring, and logging.
According to the data obtained from the Ministry of Science and Technology, Baghdad has low wind speed. Therefore, the (SUT) has been designed to generate electrical power depending on the difference between the external and internal air temperature. The temperature difference will generate a suitable airspeed to drive the wind turbine, connected to the proposed (DFIG) generators
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