LAUTECH Journal of Engineering and Technology (LAUJET)
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ENGINEERING AND GEOLOGICAL EVALUATION OF ROCKS FOR CONCRETE PRODUCTION
Get PDFEngineering and geological properties of rocks from eight different quarries in Ibadan were evaluated to determine their suitability for concrete production. Samples from each quarry sites were subjected to grading, relative density, water absorption, bulk density, amount of materials finer than 75?m, flakiness and elongation Index, Aggregate Impact Value (AIV), Aggregate Crushing Value (ACV), Aggregate Abrasion Value (AAV), 10% fines value and petrographical analysis adopting BS testing methods. The relationship between engineering properties with one another and the petrographical characteristics were described by Pearson correlation coefficient and bar charts. The results of engineering analysis revealed that rocks from all the quarries are generally sound and good because of their possession of necessary characteristics for use in concrete production when compared with British (BS), Indian (IS) and American Society for Testing and Materials (ASTM) standards. Petrographical analyses revealed that samples which have performed better in all the engineering tests possess higher content of quartz mineral and finer texture. Statistically significant correlations were found among the tests performed
PID Controller Design for Two Link Flexible Manipulator
Get PDFFlexible Link Manipulator Systems (FLMs) is more favoured in the industries when compared to the rigid link manipulator, the reason for this include: their light weight, the ease with which they can be manipulated, they consume less energy because of their light weight, and they can be manipulated faster when compared to their rigid counterpart. Despite all these advantages, controlling flexible system can pose a lot of challenges because of the distributed nature of such flexible systems. In this research work, a traditional proportional, integral derivative (PID) control system was designed for two-link flexible manipulator. The two-link robot manipulator was modelled using Lagrange and assumed mode method. The control law was developed and tested in Matlab/Simulink environment. The performance of the designed controllers is evaluated in terms of input tracking capability, energy utilization, and deflection suppression and vibration control. This study shows that a simple traditional PD/PID controller can be effectively designed for two link flexible manipulators for point to point motion control and vibration suppression
A SMART SYSTEM FOR MONITORING OIL PIPELINE INSTALLATIONS USING FIBER OPTIC SENSORS
Get PDFOil Pipeline installations are national infrastructures of high economic value. This makes monitoring and protection of such installations against the threat of economic saboteurs a national issue for any government. In this paper, a system for smart monitoring of oil pipeline using optical fiber cable is presented as a solution to the inadequacy of the traditional human and/or animal physical monitoring. The designed system employs fiber optic as sensor laid along the oil pipeline installation and a software that analyses the optical signal generated to determine the occurrence of threat to the installations. The smart system takes advantage of the effect of environmental phenomenon on optical signal traversing the optical fiber sensor in the automated monitoring of oil pipeline installations. On the basis of the mathematical relationship between light intensity and applied pressure, the system is able to determine (against a pre-set threshold), an attempt or the actual vandalization of oil pipeline installation
DRYING CHARACTERISTICS, COLOUR AND PHYTOCHEMICAL CONSTITUENTS OF BRYOPHYLLUM PINNATUM LEAVE: A FUNCTION OF PRETREATMENT AND DRYING METHODS.
Get PDFThe impact of three different drying methods (active solar, direct open sun and hot-air cabinet tray drying) and two different treatment methods (perforated and sliced) on drying characteristics, phytochemical constituents and colour of Bryophyllumpinnatum leaves were investigated. Moisture content of the leaves was measured until equilibrium moisture content is reached. The result obtained revealed that hot air cabinet drying method and slicing pretreatment improves the drying rate of Bryophyllumpinnatum leaves more than active solar and open sun drying methods. Active solar drying method and perforated pretreatment had the best Bryophyllumpinnatum leaves phytochemical constituents and colour retention during drying with brightness L*value (39±0.11), greenness a* (-70±0.60), yellowness b* (82±0.31), colour change ?E* and intensity C (131.61±0.12) and(107.81±0.90). Logarithmic model had the best potential for describing the drying characteristics of both treated and untreated Bryophylliumpinnatum leaves using active solar and cabinet drying method
ANALYTICAL DESIGN OF CGPC-BASED PID CONTROLLERS FOR COMMONLY ENCOUNTERED ENGINEERING SYSTEMS
Get PDFThe traditional PID controllers have continued to be the most widely implemented control technique in the industries for many years because of its structural simplicity and its transparent tuning rules. In this work, an analytical design method for PID controllers based on continuous generalized predictive control (CGPC) law is proposed. The design method consists of two steps. The first step entails tuning a CGPC system to obtain a satisfactory closed-loop response. Thereafter a truncated Maclaurin series is employed to approximate the designed CGPC law. Four simulation examples are used to demonstrate the effectiveness of the proposed method. The four examples used are the commonly encountered engineering systems which range from a first order plus time delay system, a second order plus time delay system, a third order system and a non-minimum phase system which has been known to be very problematic to control. The simulation results obtained showed that the proposed CGPC-based PID controllers provided good set-point tracking and disturbance rejection and compared favourably well with PID controllers designed by Ziegler-Nichols and Direct-Synthesis methods. The controllers are also found to be robust as indicated by the small values of computed sensitivity peak
DEVELOPMENT OF A MODIFIED PARTICLE SWARM OPTIMIZATION BASED CULTURAL ALGORITHM FOR SOLVING UNIVERSITY TIMETABLING PROBLEM
Get PDFTimetabling problems are search problems in which courses must be arranged around a set of timeslots so that some constraints are satisfied. However, slow convergence speed and high computational complexity are one of drawbacks limiting the efficiency of the existing timetabling algorithms. In this paper, a Modified Particle Swarm Optimization based Cultural Algorithm which is characterized with low computational complexity and high convergence speed was developed for solving university lecture timetabling problems. The standard Particle Swarm Optimization (PSO) algorithm was modified by introducing influence factors and acceleration component in order to improve the converge speed of the algorithm. Cultural algorithm was formulated by incorporating the Modified Particle Swarm Optimization (MPSO) into its population space. Thus, the developed Modified Particle Swarm Optimization based Cultural Algorithm could be implemented and employed for solving lecture timetabling problems in higher institutions
DEEPWATER PRODUCTION FORECASTING USING COMPUTATIONAL INTELLIGENCE TECHNIQUES
Get PDFPrecise and consistent production forecasting is indeed an important step for the management and planning of petroleum reservoirs. This research work is aimed at developing a new neural approach to forecast cumulative oil production. The methodology employed is using a neural network with its weight optimized with genetic algorithm (NN-GA). NN-GA overcomes the limitation of the conventional neural networks of settling in a local minima by optimizing the weights and biases to be used to initialize a Nonlinear Autoregressive Neural Network with Exogenous Input (NARX). Thus, NN-GA possesses a great potential in forecasting petroleum reservoir productions without sufficient training data. A pre-processing procedure was employed in order to reduce measurement noise in the production data from the oilfield by normalizing the raw data using z-core normalization technique and optimal network topology selection using correlation functions (CCF). Simulation studies were carried out on a deepwater reservoir located off the coast of the Niger-Delta in Nigeria, to prove the efficacy of the NN-GA in forecasting cumulative oil production of the field with data available. The results of these simulation studies indicate that the NN-GA model has a good forecasting capability with high accuracy to predict cumulative oil production and this was compared to the widely used Decline Curve Analysis technique. It was concluded that the NN-GA procedure has a very good potential to be applied to petroleum forecasting and the possibility of including more reservoir production parameters to the model to help for better accuracy and precision in the forecasting process
FORECASTING DISTRIBUTED DENIAL OF SERVICE ATTACK USING HIDDEN MARKOV MODEL
Get PDFDistributed denial of service (DDoS) attack bombards the network with loads of packets and requests that consumes the system resources in terms of time, memory, and processors. This paper presents a proposed method for forecasting DDoS in networks. The proposed model employs hidden Markov model (HMM) to forecast DDoS attacks. The method uses the inherent characteristic features of DDoS to determine the observable states of the system. To avoid intractable computations, Kullback-Leibler divergence algorithm was employed to reduce the number of observable states to three. The proposed model is formulated and trained through experiments using DARPA 2000 data set and the preliminary results shows that the characteristic features of the DDoS and the entropy concept can be used to formulate an HMM to predict DDoS
IMPROVEMENT OF THE PREDICTIONS OF A TEMPERATURE-BASED SOLAR RADIATION MODEL USING EMPIRICAL ADJUSTMENT FACTORS AT A TROPICAL STATION ILORIN, NIGERIA
Get PDFAdjustment factors for the predictions of the temperature-based Hargreaves solar radiation model were derived using historical (1996 to 2001) daily weather data for Ilorin, Nigeria. The adjustment factors (?) were estimated as ratiosof observed to predicted global solar radiation. The average daily ?were determined as a Fourier series function of Julian day by fitting the historical average daily? to the function. The year was also delineated into three seasons namely, Cool dry Harmattan, Hot dry with Early Rains and Cool Rainy seasons and the average ? for each season determined. The annual average ? was also obtained. The periods of the seasons were considered to be November through December to February for the first, March to May for the second and June to October for the third. Their determined ?-values were 0.869, 0.987 and 0.856 for the Cool dry Harmattan, Hot dry with Early Rains and Cool Rainy respectively. The annual average value was 0.894. The adjustment factors were tested by applying them to the predicted daily solar radiation for the period 2002 to 2005. The daily observed solar radiation for the period were compared with both the adjusted and unadjusted Hargreaves model predictions. The mean and root mean square of the prediction errors were found to be substantially reduced by the application of the adjustment factors. The seasonal factors were therefore recommended for locations with weather conditions similar to Ilorin but with different timings for the seasons
COMPARATIVE STUDY OF CORROSION PERFORMANCE OF ALUMINIUM- ZINC COATED, GALVANIZED AND ELECTROPLATED STEELS IN TOMATO JUICE
Get PDFMetallic materials are given prominent considerations in agro-based machinery especially in fruit juice processing, storage and use as disposable cans. Such metallic materials include Electroplated Steel (ES), Galvanized Steel (GS) and Aluminum-zinc coated steel (Aluzinc). This study evaluated the corrosion performance of Aluzinc, GS and ES in tomato juice. The medium was chosen due to its social and economic importance. Samples of Aluzinc, GS and ES were prepared by cutting into 3 x 3 cm2 from 1 mm thick plate. Three of each of the prepared samples were used for Potentiostatic Polarization Experiments (PPE) while 18 samples each were used for Weight Loss Method (WLM). Each of the prepared samples for WLM was cleaned, weighed and immersed in the media for 30 days. The samples were removed at the end of immersion, cleaned and reweighed. The results obtained for the corrosion rates in mm/y using PPE in tomato juices were 0.0061, 0.0065 and 0.0148 for Aluzinc, GS and ES respectively. The measured pH values for the media ranged from 4.1 to 8.3. Aluzinc had the lowest corrosion rate in tomato juice followed by GS and ES after 30 days of immersion using WLM