Nigerian Journal of Technological Development

ANFIS-based Indoor localization and Tracking in Wireless Sensor Networking

2024-07-01T06:12:48+00:00

Localizing wireless sensor networks poses a persistent challenge in accurately determining sensor node locations based on known anchor node positions, especially when nodes move between different locations. Conventional techniques like Trilateration, relying on Received Signal Strength Indicators (RSSIs), frequently employed in Wireless Sensor Networks (WSNs), serve the purpose of localizing and tracking moving targets. However, the inherent nonlinear relationship between RSSI and distance often leads to substantial errors in localization estimations. This paper introduces an innovative approach by proposing the utilization of an Adaptive Neural Fuzzy Inference System (ANFIS) as a departure from the conventional RSSI-based method. This ANFIS-based approach aims to initially estimate the locations of single moving targets in a 2-D WSN setup. Subsequently, these initial estimates undergo further refinement within an Unscented Kalman Filter (UKF). The results demonstrate the superior performance of the proposed algorithms in tracking targets, showcasing high accuracy levels within a few centimeters is evident from the mean localization errors for standard RSSI, ANFIS, and ANFIS+UKF, that the ANFIS+UKF framework can handle real-time target tracking issues in WSN utilizing RSSI (5.657, 0.805, and 0.068, respectively). By contrast, the proposed method offers an impressive improvement of 98.797% over the standard RSSI method.

Evaluation of MgO-ZnO-Crab Shell Biofillers as Reinforcement for Biodegradable Polylactic Acid (PLA) Composite

2024-07-01T06:27:05+00:00

Biodegradable polyester obtained from renewable, eco-friendly materials, and natural additives made from debris of production of seafood to create biocomposites is nowadays a possibility. This paper evaluates the physical, morphological, and chemical properties and the degradation stability of polylactic acid/biofillers (magnesium oxide/zinc oxide/crab shell particles) composite as a viable biocomposite material in bone engineering applications. The biofiller showed hygroscopic characteristics. Surface morphology of the composite showed fractured surfaces with interconnected pores suitable for bone cells’ implantation enhancement and propagation. Biofillers effect accelerates the precipitation of calcium apatite formation after 28 days of immersion. The XRD spectra confirmed high composite crystallinity structure of 93.4% due to the nucleation effects of the biofillers. The beneficial role of reinforcing polylactic acid polymer with biofiller showed average pH value of 7.36 and apparent porosity of 40%. Findings from this paper have revealed that the use of crab shell debris such as crab shell can become a resource in biocomposite fabrication. The addition of biofillers provided an effective reinforcement in polylactic acid polymer matrix and hence contributed towards sustainable developments of natural resource materials and biodegradable and bioresorbable material without polluting the environment.

Impact of Rice Husk Ash Based-Geopolymer on Some Geotechnical Properties of Selected Residual Tropical Soils

2024-07-01T06:37:58+00:00

There is usually a need to enhance the properties of soils with poor geotechnical properties encountered during construction. The utilisation of Rice Husk Ash (RHA) - based geopolymer for improving some properties of two selected tropical soils was investigated. The Atterberg’s limits (Liquid limit, LL and plastic limit, PL), compaction properties (maximum dry density, MDD and optimum moisture content, OMC), California bearing ratio (CBR) and unconfined compression strength (UCS) of the un-stabilized and stabilized soils were estimated. The soil samples were stabilized with alkali activated RHA varying from 3 to 15% (in 3% increment). Alkaline activation was achieved by using a mixture of NaOH(aq) and Na2SiO3(aq) in ratio 1:2. Mineralogy and elemental analysis of the un-stabilized soils, RHA and stabilized soils were obtained using X-Ray diffraction, X-Ray Fluorescence, EDS and SEM. The LL and PI of the stabilized soils decreased with as much as 30 and 40%, respectively, while the CBR and UCS increased as much as 300% and 1500%, respectively. SEM and EDS analysis of the treated soil showed the formation of crystalline hydration products. It is concluded that RHA based geopolymer is a potential environmentally sustainable stabiliser in tropical climatic condition.

Characterization And Impact Of Cutting Parameters On Face-Milled Surfaces Of Pearlitic Ductile Iron

2024-07-01T06:46:01+00:00

In an attempt to enhance the surface integrity of machined parts in the manufacturing industries, facemilled surface profiles of pearlitic ductile iron were characterized and analysed based on the effects of some cutting parameters. The pearlitic ductile iron used was locally prepared. Atomic Force Microscope and Scanning Electron Microscope were used to characterizing the roughness profile of the machined workpiece. The results showed increase in depth of cut from 400.37 to 652.37 nm at constant cutting fluid flow rate, cutting speed and feed rate. Also, at varying cutting fluid flow rate, the roughness parameter decreased from 733.56 to 272.84 nm at constant feed rate, depth of cut and cutting speed. Similar result was obtained with varying feed rate. However, there exists no definable course as cutting speed increases at constant cutting fluid flow rate, depth of cut and feed rate. In conclusion, it was found that machining at cutting fluid flow rate of 4 l/min, feed rate of 30 mm/rev, depth of cut of 0.2 mm and cutting speed of 1000 rev/min produced better quality surfaces. Therefore, the findings in this study will be useful for the manufacturing industries to improve on the surface reliability of the face milling process.