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.
تناولنا في هذه الدراسة التأكيد على تطوير المناهج الدراسية بأتجاه تنمية قيم التسامح والتعايش السلمي ، لان ثقافة التسامح باتت من الضرورات الملحة التي يفرضها الواقع الراهن لمواجهة العنف المجتمعي ، مما يوجب الحرص على ترسيخ القيم الانسانية ، لان التسامح من الصفات التي تحبها النفوس وتنجذب اليها القلوب .
والقيم الاخلاقية والسلوكية كالتسامح وغيرها ، من الامور الرئيسية لعمليتي التربية والتعليم في المدارس وال
... Show MoreThe necessary optimality conditions with Lagrange multipliers are studied and derived for a new class that includes the system of Caputo–Katugampola fractional derivatives to the optimal control problems with considering the end time free. The formula for the integral by parts has been proven for the left Caputo–Katugampola fractional derivative that contributes to the finding and deriving the necessary optimality conditions. Also, three special cases are obtained, including the study of the necessary optimality conditions when both the final time and the final state are fixed. According to convexity assumptions prove that necessary optimality conditions are sufficient optimality conditions.
... Show MoreThe research has designed for studying the relationship between manufacturing strategy and its flexibility under the flexible manufacturing system with their reflection on the competitive environmental performance of the firm. To interpret and tackle the problem, a hypothesis has formulated stating that “ the competitive performance of a firm is interpreted by the manufacturing strategy and flexibility which are derived from the firm and its business strategies under the flexible manufacturing system”. Related literatures with their theoretical dissertations, which enhanced the thoughtful content, have analyzed. An illustrative case study on the flexible manufacturing system at Toyota Motors Corporation working at the g
... Show MoreA nano-sensor for nitrotyrosine (NT) molecule was found by studying the interactions of NT molecule with new B24N24 nanocages. It was calculated using density functionals in this case. The predicted adsorption mechanisms included physical and chemical adsorption with the adsorption energy of −2.76 to −4.60 and −11.28 to −15.65 kcal mol−1, respectively. The findings show that an NT molecule greatly increases the electrical conductivity of a nanocage by creating electronic noise. Moreover, NT adsorption in the most stable complexes significantly affects the Fermi level and the work function. This means the B24N24 nanocage can detect NT as a Φ–type sensor. The recovery time was determined to be 0.3 s. The sensitivity of pure BN na
... Show MoreIn this paper, variable gain nonlinear PD and PI fuzzy logic controllers are designed and the effect of the variable gain characteristic of these controllers is analyzed to show its contribution in enhancing the performance of the closed loop system over a conventional linear PID controller. Simulation results and time domain performance characteristics show how these fuzzy controllers outperform the conventional PID controller when used to control a nonlinear plant and a plant that has time delay.
Generally fossil based fuels are used in internal combustion engines as an energy source.
Excessive use of fossil based fuels diminishes present reserves and increases the air pollution in
urban areas. This enhances the importance of the effective use of present reserves and/or to develop
new alternative fuels, which are environment friendly. Use of alternative fuel is a way of emission
control. The term “Alternative Gaseous Fuels” relates to a wide range of fuels that are in the
gaseous state at ambient conditions, whether when used on their own or as components of mixtures
with other fuels.
In this study, a single cylinder diesel engine was modified to use LPG in dual fuel mode to study
the performance, emis