Open Access Original Research Article

Assessment of Aquifer Vulnerability Using Multi-Criteria Decision Analysis around Akure Industrial Estate, Akure, Southwestern Nigeria

A. D. Adebiyi, S. O. Ilugbo, O. E. Bamidele, T. Egunjobi

Journal of Engineering Research and Reports, Page 1-13
DOI: 10.9734/jerr/2018/v3i316874

This study is aimed at evaluating of aquifer vulnerability in a typical basement complex environment of Akure industrial estate, Akure, Southwestern Nigeria. A multi-criteria model is developed for achieving this aim; the vulnerability model which is based on topsoil resistivity, longitudinal conductance, thickness of layer overlying aquifer, and hydraulic conductivity of each sounding point across the study area is successfully used to evaluate the aquifer vulnerability of the area for future groundwater development programme in the area. Geophysical investigation involving vertical electrical sounding is carried out across the study area. A total of thirty one (31) vertical electrical soundings (VES) data were acquired using Schlumberger array with maximum half-current electrode separation of 100 m. Three to five geoelectric layers were delineated across the study area. The curve types obtained are the A, H, K, KH, HA, AA, QHA and KHA.The map of topsoil resistivity, longitudinal conductance, thickness of layer overlying aquifer, and hydraulic conductivity were generated and synthesized to producing the vulnerability map. The vulnerability map shows that the area is characterized by five zones; very low, low, moderate, high and very high. The mid-western, southeastern and closure at the northern part of the study area are delineated to be very low to low vulnerable zones, followed by the eastern and part of the western and central part of the study area which are categorized as moderate vulnerable zones, and finally the southern and northern part of the study area which are characterized by high and very high vulnerable zone.

Open Access Original Research Article

Simulation Analysis of PI Based Switched Reluctance Motor

Raheel Muzzammel, Omer Ahmed Sajid, Mudassar Manzoor, Adnan Qayyum, Adil Shahzad

Journal of Engineering Research and Reports, Page 1-12
DOI: 10.9734/jerr/2018/v3i316875

Development of switched reluctance motors have revolutionized the industrial drives, aircraft applications, food processors, compressors, fans, pumps, electric vehicle application centrifuges, vacuum cleaners and many more applications because of its simpler design, ruggedness and efficiency. Researchers are highly motivated to declare switched reluctance motor as a substitute of induction motors. In this research, PI based control of switched reluctance motor is developed and analyzed under robust environment. Different performance parameters and characteristics curves are obtained in order to derive conclusions. It is concluded that speed and current are supervised effectively and torque swells are reduced significantly with this controller. Matlab/ Simulink is used for simulation analysis.

Open Access Original Research Article

Development of an Energy Storage Chamber to Enhance Solar Drying of Grain at Night

A. O. Fagunwa, O. A. Aregbesola, M. O. Faborode

Journal of Engineering Research and Reports, Page 1-10
DOI: 10.9734/jerr/2018/v3i316876

Solar drying is the one of the effective means for preserving grains and pulses. It is a simpler, cleaner and safer method of drying. However, most available solar dryers are inefficient due to non-availability of solar energy during the periods of low insolation which eventually leads to moisture re-absorption with pronounced effect particularly at night, causing growth on dried grains. To solve this problem, an energy collector and storage chamber was developed and connected to a developed solar dryer to serve as a heat source at night.

No load test was carried out at night when the dryer was subjected to four different conditions: valve opened and surface of the collector covered; valve opened and surface of the collector uncovered; valve closed and surface of the collector covered; and valve closed and surface of the collector uncovered. Load test was conducted by drying five different grains; maize, soyabean, groundnut, cowpea and sorghum during daytime using the dryer and applying the best combination of energy supplied and surface of the collector at night.

The result showed that the highest temperature difference of 35ºC and 33ºC were attained in the flat plate collector and drying chamber respectively, when the valve was opened and the surface of the collectors were covered. The load test revealed that there was a slight reduction in the moisture content of grains between midnight and 5 am. The highest moisture reduction (4%) was recorded during drying of sorghum while the least moisture reduction (1%) was recorded when drying cowpea at night. In conclusion, for continuous solar drying of grains at night using stored energy, the valve controlling the heat storage chamber should be opened and the surface of the collector should be covered to obtain optimum temperature within the drying chamber. Conserved heat energy from the energy storage chamber ensures continuous drying of smaller grains (sorghum) and at least prevents moisture re-absorption in larger grains (cowpea and maize).

Open Access Original Research Article

Switching-Algebraic Analysis of Multi-State System Reliability

Ali Muhammad Ali Rushdi, Mohamed AbdulRahman Al-Amoudi

Journal of Engineering Research and Reports, Page 1-22
DOI: 10.9734/jerr/2018/v3i316877

Multi-State systems are systems whose outputs are multi-valued (due to multiple levels of capacity or performance) and (possibly) whose inputs are also multi-valued (due to multiple performance levels or multiple modes of failure). These systems are a generalization of binary or dichotomous systems that have binary or two-valued outputs and inputs. The multi-state reliability model generalizes and adapts many of the concepts and techniques of the binary reliability model, and naturally ends up with sophisticated concepts and techniques of its own. This paper explores the possibility of simply analyzing a multi-state system by reformulating or encoding its inputs in terms of binary inputs and evaluating each of its multiple output levels as an individual binary output of these alternative inputs. This means that we dispense with multiple-valued logic in the analysis of a multi-state system, since this system is now analyzed solely via switching algebra (two-valued Boolean algebra). The wealth of tools and techniques of switching algebra are now used (without any modification or adaptation) in the analysis of the multi-state system (at the cost of an expanded input domain). The paper makes its point though the analysis of a standard commodity-supply system, whose multi-valued inputs are expressed in terms of physically-meaningfully binary inputs. The analysis is made possible through the use of advanced techniques for deriving probability–ready expressions together with the employment of large-size Karnaugh maps and utilization of multiplication tables, symmetric switching functions, and Boolean quotients. Though the system studied involves twelve binary input variables, its manual analysis is completed successfully herein, yielding results that exactly agree with those obtained earlier via automated methods, and are possibly less prone to the notorious effects of round-off errors.

Open Access Original Research Article

Mathematical Model for Solar Drying of Grains

A. O. Fagunwa, O. A. Aregbesola, M. O. Faborode

Journal of Engineering Research and Reports, Page 1-18
DOI: 10.9734/jerr/2018/v3i316878

Mathematical modeling of drying process is a complex procedure that should be carefully done. Moreso, model for solar drying, which is a unique method of drying due to constant fluctuation in the climatic conditions, requires complete integration of the complex phenomena that are involved for accurate prediction of moisture content and drying rate. A mathematical model was developed from heat and mass balance equation considering the physical and thermal properties of the grain, meteorological factors and convective heat transfer during solar drying of grains. The data obtained from the model was compared with experimental results obtained using a solar dryer to dry five selected grains – cowpea, soyabean, groundnut, maize and sorghum at airflow rates of 0.22 m/s, 0.76 m/s and 0.94 m/s. The results from statistical analysis and regression analyses used to compare the results showed that the model is adequate in predicting the moisture content and drying rate of the selected grains as well as other agricultural products with closer physical and thermal properties.