In this paper the activated sludge wastewater treatment process is modeled mathematically and explored. In addition, irrigation was recommended as a valid application for the reuse of wastewater. Other wastewater treatment processes (WWTP) were compared to the one chosen to justify the choice and a detailed expiation of the general wastewater treatment process was provided. Furthermore, PI, and PID controller were developed to further improve the performance of the activated sludge process. The controllers were devolved and tuned using MATLAB, and SIMULINK, and had a positive correlation on

We investigate linear, thermoelastic wave propagation in a layered piezoelectric material composed of a slab bonded to a half-space substrate of a dissimilar material, within dual-phase-lag model and under thermomechanical loads. One of the aims of the present work is to formulate a set of boundary conditions that is compatible with the field equations. Normal mode technique is used to obtain a solution to the considered problem. The model allows for a jump in temperature at the interface, and this can be used to evaluate a material constant of the slab. It turns out, particularly, that a

The current work is concerned with the study of wave propagation in a half-space of a piezo-thermoelastic material under a bias tangential magnetic field within dual-phase-lag (DPL). This is relevant to the design and performance of piezoelectric devices working under a bias magnetic field, for example, the DC magnetic field piezoelectric sensors widely used in various areas of technology. The characteristic time for the problem under consideration is in the range of picoseconds, which is comparable to the thermal relaxation times in many metals. Exact analytic expressions for the mechanical

This paper proposes an adaptive transmission modulation (ATM) technique for free-space optical (FSO) links over gamma-gamma turbulence channels.The ATM technique provides efficient utilization of the FSO channel capacity for improving spectral efficiency, by adapting the order of the phase-shift keying modulation scheme, according to the channel conditions and the required bit error rate (BER). To overcome the channel degradation resulting from the turbulence effects as well as the pointing errors (PEs), single-input multiple-output (SIMO) system with maximal ratio combining (MRC) is proposed

Several aspects hinder the application sustainability in construction industry. The most prominent problems are related to the conservation of natural resources and the generation of construction and demolition wastes. Previous studies indicated that these problems are due to lack of information available to construction projects stakeholders on the proper handling of building materials in their different lifecycle stages. This paper presents Material Passport (MP) tool that provides information on how to handle building materials at the construction stage and how to benefit from them at their

Expanded Polystyrene (EPS) is used as an inclusion to mitigate stresses acting on tunnels. In this study, the efficiency of utilizing EPS in reducing dynamic loads acting on shallow tunnels was studied. To gauge this, dynamic modulus of elasticity (Ed) and shear modulus (G) of EPS with densities equal to 25, 30, and 35 kg/m3 were characterized based on series of ultrasonic tests, where Ed ranged from 3500 to 6578 kPa, and G ranged from 1535 to 2741 kPa. A correlation was developed between EPS density and damping coefficient, which ranged from 1% to 2.3% based on G and the ultrasonic wave decay

A green and facile method for the synthesis of Au, Ag, and Au-Ag bimetallic nanoparticles was developed using the aqueous extract of sago pondweed (Potamogeton pectinatus L.). Size, morphology, crystallinity, composition, capping layer, and stability of the synthesized nanoparticles were all investigated. The effect of the synthesis variables on the nanoparticles was also studied. Results showed that the synthesized nanoparticles were mostly spherical in shape, although other shapes as nanotriangles and hexagons were occasionally observed. Alloy-type Au-Ag nanoparticles could be synthesized at

A new green synthesis method for the preparation of a silver-reduced graphene oxide (Ag-RGO) nanocomposite using Potamogeton pectinatus (Po) plant extract is introduced. The size, morphology and crystallinity of the as-prepared nanomaterials were studied with an explanation for the role of Po in the synthesis. A preliminary antibacterial experiment was developed to ensure the enhanced antibacterial effect of the Ag-RGO nanocomposite. The antibacterial measurements were done using the colony counting method. The results indicated that the majority of the silver nanoparticles "AgNPs" were formed

Earthmoving operations represent a sizable work in heavy civil engineering projects. Selecting optimum fleet configuration for an earthmoving operation is a very difficult process, especially when dealing with a multi loader type and multi truck type configurations. This paper presents a framework that can be used for the selection of optimum fleet for earthmoving operations. It enables the user to input the available loading and hauling equipment, then, it calculates the cost and total project time of each possible fleet combination, and finally it provides a list of the top-ten best fleet

Knowledge has been identified to be a significant organizational resource, which if used effectively can provide competitive advantage. Construction contract administration is a complex, knowledge-intensive process that if properly managed can mitigate the contractor's risk exposure. Challenges in proper knowledge management of contract administration are due to: 1) Large amount of fragmented information that is required to manage a construction contract, 2) Information located in heterogeneous sources (Request For Information (RFIs), site notices, schedules, contracts, etc...), 3) Information