An enhancement of task scheduling in cloud computing based on imperialist competitive algorithm and firefly algorithm

The Journal of Supercomputing - Cloud computing is an Internet-based approach in which all applications and files are hosted in a cloud consisting of thousands of computers that are linked in...     

Seismic evaluation of a 56‐storey residential reinforced concrete high‐rise building based on nonlinear dynamic time‐history analyses

In recent decades, shear walls and tube structures have been the most appropriate structural forms for the construction of high‐rise concrete buildings. Thus, recent Reinforced Concrete (RC) tall buildings have more complicated structural behaviour than before. Therefore, studying the structural systems and associated behaviour of these types of structures is very important. The main objective of this paper is to study the linear and nonlinear behaviour of one of the tallest RC buildings, a 56‐storey structure, located in a high seismic zone in Iran. In this tower, shear wall systems with irregular openings are utilized under both gravity and lateral loads and may result in some especial issues in the behaviour of structural elements such as shear walls and coupling beams. The analytical methodologies and the results obtained in the evaluation of life‐safety and collapse prevention of the building are also discussed. The weak zones of the structure based on the results are introduced, and a detailed discussion of some important structural aspects of the high‐rise shear wall system with consideration of the concrete time dependency and constructional sequence effects is also included. Copyright © 2010 John Wiley & Sons, Ltd.     

Computation of optimal control policy with singular subarc

Singular subarcs appear in the solution of an optimal control problem when one or more of the control variables appear linearly in both the performance index and differential constraint equations or just in the constraint equations. In such cases, the Pontryagin's⁽¹⁾ Maximum Principle yields no information regarding the possible candidates for such subarcs to be optimal trajectories, since the associated Hamiltonian is also linear in the control variables. In the chemical engineering literature such problems have been reported, for instance, in the optimal control of a continuous stirred reactor^(2,3,4) in the optimally distributed feed reactors⁽⁵⁾, in the optimal catalyst distribution along a tubular reactor^(6,7) and in the optimal design of a plug flow tubular reactor⁽⁸⁾.     

Flow and Heat Transfer Analysis in a Deformable Channel

Journal of Engineering Physics and Thermophysics - An analytical solution of the Navier–Stokes equations in a semi-infinite rectangular channel with porous and uniformly expanding or...     

Revisiting the environmental impact of financial development on economic growth and carbon emissions: evidence from South Asian economies

Clean Technologies and Environmental Policy - It is a global challenge to achieve sustainable economic growth by improving the environment. The present study discussed the role of the financial...     

Application of an air‐operated two impinging streams extractor in liquid‐liquid extraction and comparison with other contactor types

Extraction of succinic acid by means of normal butanol from its aqueous solutions (BSW), acetic acid by means of distilled water from kerosene (WAK) and iodine by means of kerosene from its aqueous solution (KIW) have been investigated in an air‐operated two impinging streams extractor (AOTISE) with spray nozzles. The effects of air flow rate, solutions flow rate, extractor length and diameter as well as modes of operation and impinging streams on extraction efficiency have been investigated. These results indicate that AOTISE is an efficient device for extraction processes. In addition, the overall volumetric mass transfer coefficients (K_La) are reported. The latter coefficients are important in design and may be used to compare the performance capability of various kinds of extractors.     

Optimization of a Lower Hitch Link for a Heavy Duty Tractor Using Finite Element Method

Links play an important role in hitching of implement to a tractor. They must withstand forces that are transmitted between tractor and implement. In modern heavy duty tractors, some type of lower link mounted force transducer is used to measure draft force. Therefore, the lower link needs to have such dimensions that stresses developed by draft force be well below of its material yield strength to safeguard any permanent set, in the meantime, avoiding high material as well as manufacturing costs might encounter due to the unnecessary large dimensions of the link. In this study, the lower link of a three-point hitch of new heavy duty ITM1500 tractor developed in Iran Tractor Manufacturing Co., was analyzed with regards to both static and dynamic conditions using finite element method. The 3-D link was modeled in Solid Works environment while Cosmos Works software was used for finite element analysis. Finally, optimum dimensions of the lower link was found with respect to available raw material and draft forces involved.     

Shrinking of Solid-state Nanopores by Direct Thermal Heating

Solid-state nanopores have emerged as useful single-molecule sensors for DNA and proteins. A novel and simple technique for solid-state nanopore fabrication is reported here. The process involves direct thermal heating of 100 to 300 nm nanopores, made by focused ion beam (FIB) milling in free-standing membranes. Direct heating results in shrinking of the silicon dioxide nanopores. The free-standing silicon dioxide membrane is softened and adatoms diffuse to a lower surface free energy. The model predicts the dynamics of the shrinking process as validated by experiments. The method described herein, can process many samples at one time. The inbuilt stress in the oxide film is also reduced due to annealing. The surface composition of the pore walls remains the same during the shrinking process. The linear shrinkage rate gives a reproducible way to control the diameter of a pore with nanometer precision.