Open Access Original Research Article

Chaos Control of a Resource-Economic-Pollution Dynamic System

Jiuli Yin, Jing Huang, Xinghua Fan

Journal of Engineering Research and Reports, Page 1-9
DOI: 10.9734/jerr/2019/v7i416974

How to control chaos in the economic system has aroused the interest of researchers. We research the chaos control in a new Resource-Economic-Pollution system by time-delayed feedback control. By determining the appropriate range of time delay τ and feedback strength k, the chaotic phenomena of the system are controlled. We verify the linear stability and the existence of Hopf bifurcation of the system. Numerical simulations show that chaos control can eliminate the chaotic behavior of the system and stabilize the system at the equilibrium point. When the time lag term is in a certain interval, the chaotic phenomenon of the system will disappear and the system will be controlled in a stable state. In practice, due to capacity and financial constraints, the firm or the government often restrains output through many methods to confine the range of fluctuations in these variables. This shows that the government or corporate decision makers have often used this approach consciously or unconsciously to promote steady economic growth.

Open Access Original Research Article

Progressive Collapse Potential of Ordinary Moment Resisting R/C Frames

Ahmed N. Khater, Fouad B. A. Beshara, Ahmed A. Mahmoud, Osama O. El-Mahdy

Journal of Engineering Research and Reports, Page 1-13
DOI: 10.9734/jerr/2019/v7i416975

A nonlinear numerical procedure in joint with suitable constitutive concrete and steel models is proposed to simulate the structural behavior and progressive collapse potential of ordinary moment-resisting frames exposed to a middle column removal scenario. Previous experimental results are used to verify the proposed non-linear finite element modelling using ANSYS program. The geometrical discretization of the ANSYS in accordance with concrete and reinforcing steel bars constitutive models have been employed in the suggested approach. The proposed numerical model succeeded in simulating the pre-peak and post-peak behavior in addition to the catenary action stage until reaching the failure of ordinary frames specimens. Numerical predictions are given for the cracking patterns, load-deflection curves, and steel strain-deflection relations.

Open Access Original Research Article

The Dynamics of Solids Removal in Waste Stabilization Ponds

I. H. Nwankwo, N. E. Nwaiwu, J. T. Nwabanne

Journal of Engineering Research and Reports, Page 1-10
DOI: 10.9734/jerr/2019/v7i416976

Waste generation at Nigerian slaughterhouses poses a serious threat to the environment because of poor handling practices which results into adverse impact on land, air and water. The aim of this research is studying the dynamics of solid removal in waste stabilization pond at different hydraulics retention times (HRT). The characteristics of wastewater in Kwata slaughterhouse were 991 mg/l, 3427 mg/l and 4419 mg/l. For total suspended solids (TSS), total dissolved solids (TDS) and total solids (TS) respectively. The slaughterhouse wastewater was treated using waste stabilization pond which comprises one anaerobic pond, one facultative pond and one maturation pond. The physio-chemical analysis conducted at the end of the treatment, shows that the total suspended solids (TSS), total dissolved solids (TDS) and total solids (TS) in an effluent leaving the maturation achieved 97%, 92% and 93% removal efficiencies. The physio-chemical analysis results were also subjected to statistical analysis using one-way analysis of variance and two-way analysis of variance without replication. The results show the statistically significant difference exists in the quality of raw wastewater, effluent from anaerobic, facultative and maturation pond.

Open Access Original Research Article

Three Phase Inverting Using Pulse Width Modulation Controlled by 6802 Motorola Microprocessor

Atef Almashakbeh

Journal of Engineering Research and Reports, Page 1-6
DOI: 10.9734/jerr/2019/v7i416977

Different types of voltage sources are available in the market, but the point is how to convert any voltage to our desired waveform? For example; if we have a DC voltage source (like battery or dc generator) and we need to run AC motor (one phase or three phases) or run DC motor with special voltage, or we have an AC source (one phase or three phases) and need to run AC machine with special voltage and special frequency or run DC machine with special voltage. In simple meaning we need a connector between the sources and loads to match between them. But it should pass this conditions; efficiency, mobility, size, weight, range of operation, simple with using and cost.

This paper focuses on designing and producing a true sinewave inverter that provides premium power which is identical to (or even better than) the power supplied by the utility company with multi output. On this work we will give an explanation for type of inverter depend on output and function for it.

Open Access Review Article

Improvement of Final Settling Tanks Performance by Using Chemical Additions

Mohamed A. E. Halawa, Hanan A. Fouad, Rehab M. Elhefny, A. F. Wail

Journal of Engineering Research and Reports, Page 1-7
DOI: 10.9734/jerr/2019/v7i416978

Biological treatment in wastewater treatment plants WWTPs consists of two main tanks, aeration tank and final settling tank. Aeration process using in return activated sludge system is very costly and it is required to operate WWTPs with low dissolved oxygen (DO) concentration in aeration process without risking poor effluent quality. To apply this study, a plant model for the addition of chemicals must be made with the necessary calibration of this model. Laboratory experiments were started between November 2017 and June 2018. This paper will discuss the impact of DO concentration on sludge properties by using a pilot plant model WWTP and find the optimum doses of Hydrogen peroxide H2O2 concentration with using low DO concentration to achieve good sedimentation.  In this study the DO set-point was changed every 3 weeks between 0.5 mg/l and 4.5 mg/l for a few months.  Experiments were carried out to The optimal ratio and dosage of H2O2 /Fe+2 was 5 as 30/6 mg/l. BOD, COD, TSS and VSS removal efficiency by using H2O2 /Fe+2 were 91%, 89% 90% & 89%, respectively with DO = 1.5 mg/l at an increased rates were 21.3%, 25.4%, 20% & 12.7%, respectively. Results of paper proves that the addition of optimum H2O2 will save 2 mg/l of DO concentration and providing a high cost of using electricity and mechanical equipment compared to the non-use of H2O2.