Recently, the construction of water structures and seepage reduction are critical issues. This importance was induced due to the required specifications for the desired type of concrete. Mechanical strength and permeability are the two major parameters in achieving the design mix efficiently. This study investigates the effect of different types of admixures on the performance of concrete. The performance of concrete was evaluated using the mechanical strength and permeability tests. The concrete mixes admixtures include A retarder (Sika R2004 type G), water proofing material (addicrete DM2)
A new approach is proposed to accelerate the convergence of the Lattice Boltzmann method for steady-state problems. The proposed approach uses an adaptive relaxation frequency to accelerate the convergence by assigning more weight to selected parts of the standard algorithm corresponding to different phases of the convergence to the steady-state solution. The proposed algorithm is simple, straightforward and does not impose any additional computational cost to the standard algorithm. Different simulation cases are presented with the corresponding speedup. Finally, guidelines for the selection
This work is dedicated to the economic scheduling of the required electric stations in the upcoming 10-year long-term plan. The calculation of the required electric stations is carried out by estimating the yearly consumption of electricity over a long-time plan and then determining the required number of stations. The aim is to minimize the total establishing and operating costs of the stations based on a mathematical programming model with nonlinear objective function and integer decision variables. The introduced model is applied for a real practical case study to conclude the number of
Daily, a big extent of colored, partially treated textile effluents drained into the sanitation systems causing serious environmental concerns. Therefore, the decolorization treatment process of wastewater is crucial to improve effluent quality. In the present study, 3 different sorbent materials, nano zerovalent iron (nZVI), activated carbon (AC), and green-synthesized nano zerovalent iron (GT-nZVI), have been prepared for raw textile wastewater decolourization. The prepared nanomaterials were characterized via X-ray diffraction (XRD) spectroscopy, scanning electron microscopy (SEM), energy
Understanding of deterioration mechanisms in sewers helps asset managers in developing prediction models for estimating whether or not sewer collapse is likely. Effective utilisation of deterioration prediction models along with the development and use of life cycle maintenance cost analysis contribute to reducing operation and maintenance costs in sewer systems. This article presents a model for life-cycle maintenance planning of deteriorating sewer network as a multi-objective optimisation problem that treats the sewer network condition and service life as well as life-cycle maintenance cost
This paper presents a framework for optimizing condition assessment policies by balancing the revealed value of information with the cost of obtaining such information. The computational platform is based on augmenting the asset condition state with an expected level of accuracy. Inaccuracies due to condition assessment reliability are evaluated using the partially observable Markov decision process. The single objective genetic algorithm is used to select the most cost-effective assets to assess considering information inaccuracy under a fixed budget. The model is extended using
With ageing water and sewer infrastructure in North America, assessing the condition of these assets has received increased attention in the past few years. Condition assessment is an integral component in any asset management program. Determining the condition of buried infrastructure tends to be more cumbersome, costly and error-prone compared to other surface infrastructure like roads and buildings. For sewers, CCTV is considered the industry standard for condition assessment technologies. For pressurized water pipelines, technologies tend to be more costly and uncertain (e.g
This paper illustrates the design of proportional–integral–derivative controller (PID) controller of 10 KW air heaters for achieving the set point temperature as fast as possible with minimum response overshoot. Computational fluid dynamic (CFD) numerical simulations are utilized to predict the natural response of 10 KW input power for the air heater. CFD results are validated with experimental empirical correlations that insure the reliability of open loop results. The open loop response of CFD transient simulations is used to model the air heater transfer function and design the classical
Organic solar cells have many advantages such as their ease of manufacturing, flexibility, and low cost compared to perovskite and silicon solar cells. However, increasing their power conversion efficiency (PCE) is still challenging. In this paper, response surface methodology of design of experiments (DOE) is used to optimize the PCE of a tandem organic solar cell. The cell is based on boron sub-phthalocyanine to reduce the series resistance between the layers. The optimization process is performed by formulating an empirical polynomial regression model relating the PCE to the active layers'