Temperature Performance Evaluation of Parabolic Dishes Covered with Different Materials in Iwo, Nigeria

Solar radiation reaching the earth is considered to be affected by some parameters like diffusion. This radiation is reflected or scattered by air molecules, cloud and aerosols (dust). Parabolic dishes made of different materials (glass, foil and painted surface) were used to concentrate energy on a copper calorimeter filled with water. A thermometer was inserted in each of the copper calorimeter placed at the focus of the dishes. The experiment was performed from March to April (a period of five weeks), from 9:00am to 5:00pm daily with readings obtained at intervals of 30 minutes every day for one week and was later changed to hourly readings for the remaining four weeks. The initial and final temperatures of the water were determined. The parabolic dish with glass material gave the highest temperature of 56.9oC followed by foil with an average temperature of 48.7oC and painted silver colour with an average temperature of 45.1oC for the daily variation. For the other weeks, the average temperature of the dish with glass was 57.6oC  for foil, 46.9oC and painted silver colour, 40.8oC. The parabolic dish with glass is able to generate a higher temperature compared with foil and painted silver colour. Keywords: Glass, Foil, Silver Colour and Parabolic Dish

Effect of Coolant Temperature on Machining Characteristics of High Carbon Steel

This paper reports on the effect of coolant temperature on machining of high carbon steels. The development of a cooling system to reduce the temperature of water soluble coolant to 7.9oC from ambient temperature was employed in this work to improve the machining performance. The experiments were performed using cooled and ambient temperatures by employing Taguchi L18 orthogonal array to design the experimental runs. The cutting speed, feed rate and depth of cut were the machining parameters used; while the tool-work piece interface temperature was monitored using a digital thermometer with k-type thermocouple wire. The selected control factors are material removal rate and surface roughness. The experimental results were analyzed using Minitab 16. The main effects and percentage contributions of various parameters affecting surface roughness and material removal rate were discussed, and the optimal cutting conditions were determined. It was observed that surface finish improved by 65% with the use of the developed cooled system. The reduction in coolant temperature played a vital role in improving surface finish during machining high carbon steels

PID Controller Design for Two Link Flexible Manipulator

Flexible 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

Design, Fabrication and Performance Evaluation of Awning/Canopy for Thermal Comfortability

This paper presents the design, fabrication and performance evaluation of retractable awning/canopy system for thermal comfortability. It consists of frame (mild steel bars), linear actuator, fabric (acrylic), adapter, roller pathways and photo sensor (for easiness of control). After fabrication and coupling of the whole components of the retractable awning system, it was connected to the adapter and power source for performance test evaluation. It was observed that, the actuator arm which was coupled to the fabric began projecting outward and once the photo sensor was shaded from sunlight using a dark material, the fabric retracted into the roller. Also a reduced solar heat gain factor of 28.16 W was achieved by shading the window compared to the solar gain factor of 498.54 W before shading with a cooling load of 415.37 W. This can be incorporated into building plans especially those at the sunheating direction and tropical region to reduce inner-house temperature air-conditioner loading for longer life and efficient operation

Investigation of Thermal Insulation Properties of Biomass Composites

This paper reports on the investigation of thermal properties of Kapok, Coconut fibre and Sugarcane bagasse composite materials using molasses as a binder. The composite materials were moulded into 12 cylindrical samples using Kapok, Bagasse, Coconut fibre, Kapok and Bagasse in the ratios of (70:30; 50:50 and 30:70), Kapok and Coconut fibre in the ratios of (70:30; 50:50 and 30:70), as well as a combination of Kapok, Bagasse and Coconut fibre in ratios of (50:10:40; 50:40:10 and 50:30:20). The sample size is a 60mm diameter with 10mm – 22mm thickness compressed at a constant load of 180N using a Budenberg compression machine. Thermal conductivity and diffusivity tests were carried out using thermocouples and the results were read out on a Digital Multimeter MY64 (Model: MBEB094816), while a Digital fluke K/J thermocouple meter PRD-011 (S/NO 6835050) was used to obtain the temperature measurement for diffusivity. It was observed that of all the twelve samples moulded, Bagasse, Kapok plus Bagasse (50:50), Kapok plus Coconut fibre (50:50) and Kapok plus Bagasse plus Coconut fibre (50:40:10) has the lowest thermal conductivity of 0.0074, 0.0106, 0.0132, and 0.0127 W/(m-K) respectively and the highest thermal resistivity. In this regard, Bagasse has the lowest thermal conductivity followed by Kapok plus Bagasse (50:50), Kapok plus Bagasse plus Coconut fibre (50:40:10) and Kapok plus Coconut fibre (50:50)

Meteorological parameters study and temperature forecasting in selected stations in Sub-Sahara Africa using MERRA-2 data

The study and forecast of climatic phenomena have progressed over time, but the huge knowledge with information gathered has aided in comprehending and anticipating weather changes. The goal of this research was to look at some specific meteorological characteristics and forecast air temperature over a number of stations in Osun State, Nigeria. Monthly rainfall, relative humidity, air temperature, air pressure, wind speed and direction for four stations were gathered from the HelioClim website archives and used in this study. For each variable, descriptive statistics were calculated. The normality of the data was determined using the Shapiro-Wilks test. The data was tested for stationarity using the Augmented Dickey Fuller (ADF) test, and different types of Autoregressive Integrated Moving Average (ARIMA) models were fitted. According to the statistics, the highest average temperature was observed in March (=23.90). The months of June, July, August, and September had the highest mean relative humidity (=88.4%), pressure (=987ℎ), wind speed (=1.8/), wind direction (=225.10), and rainfall (=413). In January, the coefficient of variation (COV) for temperature was larger than in other months. In June, January, and December, relative humidity (RH), air pressure, rainfall, and wind speed and direction were all higher. The air temperature stationarity was tested using the Augmented Dickey Fuller (ADF) test, which revealed (p>0.05) but became stationary after the first difference (p<0.05). The temperature effect follows the same trend in ARIMA (1, 1, 1) forecasts for 2021 and 2022. As a result, air temperature modeling and forecasting are difficult tasks for any monthly time series. It is advised that all-time series models for any investigated location be considered, as well as meteorological conditions, in order to select the most appropriate model