Browsing by Author "Akpenpuun, Timothy Denen"
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Item DETERMINATION OF OVERALL HEAT TRANSFER COEFFICIENT FOR GREENHOUSE ENERGY-SAVING SCREEN USING TRNSYS AND HOTBOX(Biosystems Engineering, 2022) Rabiu, Anis; Na, Wook Ho; Akpenpuun, Timothy Denen; Adesanya, Misbaudeen Aderemi; Ogunlowo, Qazeem Opeyemi; Kim, Hyeon-Tae; Lee, Hyun-WooThe high energy consumption in the greenhouse during the winter season necessitates the development of various thermal screens for energy-saving purposes. However, there is limited data on the precise properties of thermal screens, while little research has investigated a methodological approach for measuring the screen's energy-saving capacity for greenhouse energy efficiency. This research aims to determine the thermophysical, radiative, and aerodynamic properties of selected commercial greenhouse thermal screens. The transient system simulation (TRNSYS) model was used to simulate the heat flux and derive the thermal retention qualities of the thermal screens through their measured properties. The model was validated by comparing the simulated and experimental heat transfer coefficients, expressed as the overall heat transfer coefficient (U-value), thereby determining the thermal retention of the screens. In addition, the simulated U-value was compared to the experimental U-value in material permeability to investigate the influence of screen porosity on heat loss. The statistical analysis t-test was conducted to compare the U-values obtained from the simulation and the experimental hotbox. The simulated Uvalues (for computed permeability) indicated that samples M1 and M3 exhibited the lowest U-value of 4.4 W m 2 K 1, while white polyester, Luxous, PH-super, PH-66, M2, Clima45 (0), and New-Lux showed higher U-values of 82%, 105%, 161%, 123%, 41%, 102%, and 118%,Uvalde respectively. Because of their low material porosity, M1, M2, and M3 samples showed better greenhouse thermal retention over others. Conclusively, the permeability features of the greenhouse energy screen materials have a substantial impact on their U-values.Item DYNAMIC NEURAL NETWORK MODELING OF THERMAL ENVIRONMENTS OF TWO ADJACENT SINGLE-SPAN GREENHOUSES WITH DIFFERENT THERMAL CURTAIN POSITIONS(2024) Akpenpuun, Timothy Denen; Ogunlowo, Qazeem Opeyemi; Na, Wook-Ho; Dutta, Prabhat; Rabiu, Anis; Adesanya, Misbaudeen Aderemi; Nariman, Mohammadreza; Zakir, Ezatullah; Kim, Hyeon-Tae; Lee, Hyun-WooIn order to produce marketable yield, scientific methodologies must be used to forecast the greenhouse microclimate, which is affected by the surrounding macroclimate and crop management techniques. The MATLAB tool NARX was used in this study to predict the strawberry yield, indoor air temperature, relative humidity, and vapor pressure deficit using input parameters such as indoor air temperature, relative humidity, solar radiation, indoor roof temperature, and indoor relative humidity. The data were normalized to improve the accuracy of the model, which was developed using the Levenberg–Marquardt backpropagation algorithm. The accuracy of the models was determined using various evaluation metrics, such as the coefficient of determination, mean square error, root mean square error, mean absolute deviation, and Nash–Sutcliffe efficiency coefficient. The results showed that the models had a high level of accuracy, with no significant difference between the experimental and predicted values. The VPD model was found to be the most important as it influences crop metabolic activities and its accuracy can be used as an indoor climate control parameter.Item Evaluation of Potential of Activated Locust Bean Pod as a Coagulant for Domestic Sewage Treatment(Kaunas University of Technology, 2017) Akpenpuun, Timothy Denen; Akinyemi, Banjo A; Adeniran, Kamoru Akanni; Sulaiman, M.F.; Adelodun, BashirAn investigation was carried out on the coagulation potential of the activated locust bean pod in comparison with aluminium sulphate (alum) in the treatment of domestic sewage. The treatments included control cul ture (water without alum and activated locust bean pod treatment), 3.5 g/L of the activated locust bean pod, 4.5 g/L of the activated locust bean pod and 4.5 g/L of alum. All the treatments were cultured in 16-litre buc kets. Physical, chemical and bacteriological properties of domestic sewage were determined before and after the application of the coagulants on a weekly basis. The result showed that 1.14 NTU of turbidity was removed from an initial value of 6.34 NTU using 4.5 g/L of the activated locust bean pod. For the samples treated with 4.5 g/L of alum, turbidity reduced to 0.36 NTU, while 0.46 NTU was removed from the control experiment. pH values show that the pH of the samples decreased from6.83 to 4.05, 6.83 to 6.00and 6.83 to 6.15 for the activated locust bean pod, alum and the control tanks, respectively. The result shows that the activated locust bean pod acidified waste water. The result showed that 3.5 g/L and 4.5 g/L of the activated locust bean pod and alum removed about 0.98% and 1.90% of BOD5, respectively, while BOD5 in the control experiment reduced by 0.26% from the initial value of 6. A significant removal of coliform counts activated locust bean pod was observed. The study shows that the activated locust bean pod can be used in place of alum, which is dependent on the end use of treated waterItem IMPACT OF A SPLIT-GABLE GREENHOUSE MICROCLIMATE ON THE YIELD OF IRISH POTATO (SOLANUM TUBEROSUM L.) UNDER TROPICAL CONDITIONS(Nigeria Institution of Agricultural Engineers - Journal of Agricultural Engineering and Technology (JAET), 2020-12-15) Akpenpuun, Timothy Denen; Mijinyawa, YahayaProduction of Irish potato is limited to a temperate climate. Increasing demand for this crop has necessitated the introduction of other production options. A possible option is the use of controlled environment agriculture. This study was designed to investigate split-gable greenhouse microclimatic conditions for Irish potato production under tropical conditions. The split-gable greenhouse was developed for tropical conditions and equipped with humidifiers and circulating fan for climate control. Data loggers and a weather station were installed in- and outside the greenhouse to monitor the climate. Five varieties of Irish potato (Nicola, Diamant, Bertita, New seed, Okonkwo) were cultivated in- and outside the greenhouse in two rainy- and dry- seasons. Three seedlings of each variety were planted with 10 replicates using Completely Randomised Design (CRD). The air temperature, Relative Humidity (RH) and Vapour Pressure Deficit (VPD)of the greenhouse were measured in accordance with standard procedures. Yield obtained were compared with standard yield values. Data were subjected to regression analysis and ANOVA at α0.05.Greenhouse floor, wall, roof, glazing, ventilation area and volume were 48.0, 84.0, 52.4, 108.4, 32.8 m2 and 175.4 m3, respectively. The humidifier and fan had capacities 7.4 g of H2O/kg of air.h and 2.5 m3/s air flow rate, respectively. The thickness and light transmittance of the glazing material was 2 mm and 75%, respectively. The pitches, rises and pitch angles of the split-gable roof were 0.3/0.2, 1.6/1.0 m and 15.1o/9.7o, respectively. Rainy season temperature, RH and VPD were 23.6±1.1oC, 82.3±2.8% and 0.5±0.1 kPa, respectively inside the greenhouse compared with 29.3±1.2oC, 78.5±7.3% and 1.2±0.2 kPa outside the greenhouse. Dry season temperature, RH and VPD were 25.5±2.7oC, 75.3±2.4% and 0.7±0.3 kPa, respectively inside the greenhouse compared with 36.1±1.9oC, 63.12±10.4% and 2.2±0.7 kPa, respectively outside the greenhouse. Greenhouse microclimatic conditions were within the reported threshold of 15-35oC, 70-85% and 0.4-1.0 kPa necessary for potato production. Bertita and New seed had the highest yield of 6.4 and 6.1 kgm-2, respectively in rainy season and 5.3 and 5.4 kgm-2, respectively in the dry season inside the greenhouse. New seed gave the highest yield of 1.7 kgm-2 outside the greenhouse both in rainy- and dry- seasons, while Okonkwo had the least 0.2 kgm-2 outside the greenhouse in dry season. Reported equivalent mean yield in au State for the five varieties were in the range 7.6-11.3 kgm-2. Climatic data and yield in- and out- side the greenhouse differed significantly. Temperature, RH and VPD had significant interactions with yield. A split-gable greenhouse that provided suitable microclimatic conditions for Irish potato production in tropical conditions was developed.Item MAXIMISING STRAWBERRY YIELD IN SINGLE-LAYERED AND DOUBLE-LAYERED GOTHIC GREENHOUSES- A MICROCLIMATE APPROACH(Journal of Applied Sciences and Environmental Management, 2023-07-29) Akpenpuun, Timothy Denen; Lee, Hyun-WooSeolhyang variety of strawberry was grown in two gothic greenhouses with one layer and two layers of glazing material and a layer of shading screen. The objective of the study was to optimise strawberry yield using temperature, relative humidity (RH), vapour pressure deficit (VPD), and solar radiation (SR) in a single-layered (1Lgh) and double-layered (2Lgh) single-span gothic greenhouse. Greenhouse climate data were recorded using standard data loggers and sensors. The data were analysed using descriptive and inferential analysis. During the day, significant differences were observed between the 1Lgh and 2Lgh in terms of VPD and SR, while during the night, significant differences were found in RH and VPD (p<0.01). The yield in the 1Lgh was 3.2% higher than in the 2Lgh, the higher daytime VPD and lower nighttime RH in the 1Lgh may possibly explain this observation. The environmental parameters had significant interaction on yield with resultant R2 values of 0.80 and 0.50 for 1Lgh and 2Lgh, respectively.Item SIMULATION OF GREENHOUSE ENERGY AND STRAWBERRY (Seolhyang sp.) YIELD USING TRNSYS DVBES: A BASE CASE(2023) Ogunlowo, Qazeem Opeyemi; Akpenpuun, Timothy Denen; Na, Wook Ho; Adesanya, Misbaudeen Aderemi; Rabiu, Anis; Dutta, Prabhat; Kim, Hyeon-Tae; Lee, Hyun-WooThis research establishes a base case scenario encompassing the energy behavior of the greenhouse and its direct influence on the yield of strawberries (Seolhyang sp.) to evaluate the performance of the greenhouse energy demand and its effect on crop yield. The objective is to develop a ventilated discretized volume building energy simulation (DVBES) that predicts energy demand, temperature, and relative humidity (RH) of a greenhouse and develop a predictive strawberry yield model that predicts the strawberry yield. This study used two single-span double-layer experimental greenhouses with different features. Experimentation was conducted in the winter season of 2021–2022 and 2022–2023. Hourly temperature, RH, and daily fuel consumption were used to validate the DVBES model. Weekly temperature, RH, solar radiation (SR), and yield were used to validate the strawberry yield model. The results show high prediction accuracy with minor errors. For a single-span double-layer greenhouse at E–W (90◦) orientation, the total energy demand and strawberry yield were 113.861 MJ.m 2 and 0.466 kg.plant 1.season 1, respectively. The findings serve as a foundation for further research on optimizing energy consumption in greenhouse environments. This research contributes to advancing knowledge in sustainable agriculture and facilitates the transition toward a greener and more resource-conscious future.Item THERMAL PERFORMANCE AND ENERGY COST OF KOREAN MULTISPAN GREENHOUSE ENERGY-SAVING SCREENS(Energy, 2023) Rabiu, Anis; Adesanya, Misbaudeen Aderemi; Na, Wook-Ho; Ogunlowo, Qazeem Opeyemi; Akpenpuun, Timothy Denen; Kim, Hyeon Tae; Lee, Hyun-WooProtected agricultural system such as a greenhouse cultivation is increasingly replacing traditional farming systems. Nonetheless, high energy demand in greenhouse farming requires innovative technologies through the use of climate screens to ensure sustainable production. Thus, this study developed a novel methodology for examining the energy retention capacity and economic effectiveness of greenhouse climate screen materials using their thermophysical, radiometric and aerodynamic properties in TRNSYS software. The TRNSYS model was developed to determine the energy consumption, which was validated using a multi-span Venlo-type experimental greenhouse (Yeoju, South Korea). Further analyses on energy saving capacity of different screens and the equivalent energy costs were performed. The results from this research showed that among the fifteen investigated screens, the ensemble screen (M3) saved 34.09 kWh.m 2 of annual energy, equivalent to 60 % of the heating energy demand, and energy cost of 4490.26 Korean won. m 2. Further, the results revealed that the climate screens with multi-layer, thermoreflective, low longwave transmissivity, impermeable and aluminized strips or surface characteristics and features have a considerable impact on reducing greenhouse energy use and desirable for high energy-saving. This research has demonstrated that the techniques and methods utilised can investigate all the types of covering and thermal screens used in greenhouse.Item The use of red earth, lateritic soils and quarry dust as an alternative building material in sandcrete block(Elsevier - Scientific African, 2020-01-13) Akinyemi, Banjo A.; Alhassan, Elijah; Oluwasegun, Aladegboye; Akpenpuun, Timothy Denen; Owolaja, GloryThis study investigated the prospect of utilising red earth, quarry dust and laterite as alter- native materials to river sand in the production of sandcrete blocks. Compressive strength test was performed on the samples at 7, 14, 21 and 28 curing days in the laboratory. The effect of curing on strength improvement was also studied. Using one way analysis of vari- ance (ANOVA) and Tukey analysis, the results showed that quarry dust and lateritic soil performed relatively better in comparison with the traditional river sand used in sandcrete blocks production. Also there was progressive improvement of the compressive strength of the tested materials over the period of curing regime adopted for the study. Red earth and quarry dusts showed good prospect as alternative to the use of river sand in sandcrete block production for developing nations.