Open Access Original Research Article

Path Loss Modeling for Next Generation Wireless Network Using Fuzzy Logic - Spline Interpolation Technique

A. Danladi, P. G. Vasira

Journal of Engineering Research and Reports, Page 1-10
DOI: 10.9734/jerr/2018/v1i39815

Appropriate path loss mathematical models help in reducing the complexity of the co-channel interference of Global System for Mobile Communication and Wireless Networks. This work proposes, to adopt and modify Hata model using fuzzy logic and spline interpolation techniques. Mean absolute errors of 1.55 dB and 0.4 dB were obtained using the techniques respectively. It was found that, using fuzzy logic - spline interpolation model, path loss is minimized by 1.94 dB in the study area. Therefore, fuzzy logic - spline interpolation is recommended for path loss prediction for next generation wireless networks in medium cities in Nigeria especially Yola. It is suggested that, neuro – fuzzy spline interpolation may be used to further minimize path loss error for medium cities.

Open Access Original Research Article

Comparative Analysis of Autogenous and Media Assisted Grindability of a Copper and Manganese Ores

E. O. Ajaka, G. Dombo, O. Abiodun

Journal of Engineering Research and Reports, Page 1-12
DOI: 10.9734/jerr/2018/v1i39824

This paper presents a comparative analysis of autogenous and media assisted grinding of a manganese ore and copper ore both obtained from Otjihase in Namibia. The objective was to understand the relationship between ore properties and Grindability and thus effectively select comminution circuit and equipment based on this relationship. Laboratory studies were carried out to determine the ease of grinding the ore samples relative to one another. The sample of known weight was crushed and the particles thoroughly homogenized for sieve size analysis and Grindability tests. The Grindability test on each ore was both autogenous and media assisted for dry grinding at -250 microns with constant mill charge of 200 g per run, media charge of 40% by weight and mill operations of 100 to 500 revolutions corresponding to mill speeds of 5 to 25 rpm. The Grindability index of each ore was calculated and compared based on the tests results and used to calculate work indexes for the ores based on the Bond’s model. The autogenous tests produced average Grindability values of 0.55 kg/ton/rev and 0.65 kg/ton/rev for the copper and manganese ores respectively; and media assisted tests gave average values of 0.8 kg/ton/rev and 1.45 kg/ton/rev respectively for the copper and manganese ores. The results show that although media charge grinding produced higher Grindability values, both ores are economically amenable to autogenous grinding which suggests that with proper circuit design, the use of autogenous grinding for these ores (especially the manganese) can save significant cost. The results also show that Grindability increases with mill speed up to an optimum value beyond which grindability decreases with increasing speed and may even drop to zero while mill is running. It is also observed that grindability has close relationship with ore properties especially hardness and compressive strength. It should be noted that the inefficiency factors for the grinding are not considered in these results.

Open Access Original Research Article

Modelling and Simulation of Deposit Slip Mode of Bank Cash Deposit Transactions Using Hierarchical Timed Coloured Petri-Nets

O. O. Olusanya, E. O. Omidiora, S. O. Olabiyisi, R. A. Ganiyu

Journal of Engineering Research and Reports, Page 1-7
DOI: 10.9734/jerr/2018/v1i39830

Significant investments are being made yearly to improve service quality and delivery in banking systems to minimise customers' dissatisfactions with long waiting time due to overcrowding. However, most existing empirical studies to address this problem employed the method where the system was modelled and then developed a program that will simulate, analyse and validate the developed model. This paper conceptualised modelling bank cash deposit transactions characterised by Deposit Slip (DS) using Hierarchical Timed Coloured Petri Nets (HCPN). The HTPC model developed was simulated using Coloured Petri Nets tools. The model was validated by comparing the simulated results with the real average flow time of the customers and utilisation rate of servers using statistical t-test at p< 0.05.

This model is useful for bank decision makers in capacity building to enhance service quality and delivery.

Open Access Original Research Article

Influence of Compressive, Tensile and Fatigue Stresses on Asphalt and Concrete Cement Road Pavements in Nigeria - Using Linear Elastic Theory

J. E. Ogbezode, A. I. Adeleke, A. S. Adebayo

Journal of Engineering Research and Reports, Page 1-19
DOI: 10.9734/jerr/2018/v1i39849

The high brittle nature of pavement structures have been  carefully examined based on compressive, tensile strain and the harsh effects of fatigue cycle with reference to the base layer thicknesses and elastic strains during and after construction were examined. Subjection of asphalt and concrete-cement pavements to traffic loading and tyre pressure also influences the vertical stress and strain values for the asphalt and concrete materials under the same axial loading conditions. Using various fundamental equations under linear elastic conditions for the analysis of Asphalt and Concrete Cement structure revealed that both materials do respond differently to compressive and tensile stresses under similar mechanical conditions. Effect of compressive stresses and strains on concrete pavement is larger compare to asphalt pavement due to large thickness sub-base layer of its pavement structure. Both pavement layer thicknesses are independent of fatigue cycle under harsh traffic loading. Thus, concrete pavement has shown better fatigue resistance and less tensile strain values than asphalt pavements due to high pavement layer thickness regardless of the load distribution.

Open Access Original Research Article

Equilibrium, Kinetics and Thermodynamics of the Bleaching of Palm Oil Using Activated Nando Clay

Nwabanne, Joseph T., Onu, Chijioke E., Nwankwoukwu, Okwudili C.

Journal of Engineering Research and Reports, Page 1-13
DOI: 10.9734/jerr/2018/v1i39855

The effectiveness of Nando clay in the bleaching of palm oil was studied in this work. The clay was prepared by activating it with hydrochloric acid. The bleaching was carried out at different temperatures, adsorbent dosage and particle sizes. The result suggests that increase in temperature and adsorbent dosage increases the bleaching efficiency while the increase in particle size decreases the bleaching efficiency. Both the pseudo-first-order and the pseudo-second-order kinetic models describe efficiently the experimental data of the bleaching process. Intra-particle diffusion though involved in the adsorptive bleaching mechanism, is not the sole rate-limiting step in the bleaching of palm oil with activated Nando clay. The equilibrium data were described better by Langmuir and Freundlich models. The enthalpy, entropy and activation energy were determined to be 6.127 KJ/mol, 3.982 KJ/mol and 15.281 KJ respectively. The free energy was found to vary between- 3.999 to- 3.760 KJ/mol. The result indicates that bleaching efficiency of up to 96% can be obtained with the activated clay as an adsorbent.