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Greenhouses offer controlled microclimates that enable year-round cultivation, improving food security and agricultural productivity. However, greenhouses are energy-intensive, with heating accounting for a significant portion of the associated costs. This study explores optimal microgrid configurations, economic viability, and policy recommendations for sustainable greenhouse agriculture in Nigeria. An in-depth energy assessment of a reference greenhouse in a South Korean facility is conducted. Distinct climatic differences between South Korea and Nigeria are highlighted, emphasizing the need for tailored greenhouse designs and energy solutions. Shifting focus to Nigeria, this study investigates the feasibility of hybrid renewable energy systems with a focus on wind and solar power across six geopolitical zones in Nigeria. The analysis encompasses technical, economic, and policy aspects, providing a holistic perspective on renewable energy adoption. Notably, the study uses an advanced optimization model, Teaching and Learning–Based Optimization algorithm, to assess the net present cost and baseload supply reliability, offering valuable insights for investors and policymakers. The result indicates diverse energy requirements across Nigeria, with total monthly peak energy demands ranging from 5374.80 kWh in the Southeast to 17,115.76 kWh in the Northwest, and a notable variation in the Levelized Cost of Electricity (LCOE), with the lowest at $0.07327 in Kano. Specifically, in Ogun, the net present cost for the WT-PV-ESS system stood at $520,935.45, while the PV-ESS system cost was substantially lower at $500,444.41. This confirms the effectiveness of location-specific analysis and shows the suitability of photovoltaic–battery energy storage systems for Nigeria's diverse regions, with unique considerations for specific areas. Policy recommendations, including feed-in tariffs, renewable portfolio standards, net metering, research support, and market development, provide a holistic framework for the adoption of renewable energy and sustainable agriculture. Improving infrastructure, market access, and financing for smallholder farmers is integral for improving food security and standards of living in rural Nigeria. In conclusion, Nigeria can leverage renewable resources to revolutionize its energy and agriculture sectors, setting an example for a sustainable and resilient future.

Floods are among the most severe hazards around the world triggered by climate change, threatening environmental sustainability, economies, and ecological cycles and damaging infrastructure and causing loss of lives. We aimed to prepare a flood susceptibility map of Kathmandu metropolitan city (KMC) and identify the most flood-susceptible local administrative unit using a multi-criteria decision analysis model, including the analytical hierarchical process and weighted linear combination in geographic information system. Six flood hazard criteria—slope, elevation, drainage density, rainfall, land use and cover, and distance from river—were proposed to produce a flood susceptibility map. Among them, distance from river was the most significant criterion followed by rainfall and land use and land cover. The results showed that a large proportion (56%) of KMC is in moderate flood potential zone, while 32% and 11% proportions of KMC are in high and low flood potential zones, respectively. Wards 4 and 14 of KMC are the highest and lowest flood prone zones, respectively. The accuracy of the obtained map by multicriteria decision model is 81.2%, which was validated through observation of the significant flood events and flood location. These findings are useful for flood risk mitigation and logical allocation of programme budget to the local units. The procedures applied in this study are helpful for hydrologists, urban planners, policymakers, and professionals in hydrology.

The buildings sector is responsible for over 36% of total global end-use energy utilization and nearly 40% of the total indirect and direct carbon emissions. Low-carbon or zero-energy buildings remain the only option to lessen the sector’s energy consumption and CO2 emissions. The current systematic study examines low-carbon buildings under deep decarbonization scenarios in selected global south regions from 2010 to 2021. The study was channelled by the PRISMA (“Preferred Reporting Items for Systematic reviews and Meta-Analyses”) review process, which identified 29 related articles from Scopus, Web of Science., and Google Scholar databases. The identified critical drivers of emissions were population, gross domestic product, dwelling characteristics, and urbanization. The dwelling characteristics contributed about 12% and 27% to the total CO2 emissions in the selected regions. The population varies between 23% and 27% across the areas. Specific findings were made for inclusion in the Nigeria model while the general results were observed and further studies proposed. Total investment from the private and public sectors was identified as key to achieving the transition process of decarbonization in the building sector.

This paper is based on a techno-economic analysis and the environmental impact of a proposed 1 MW solar photovoltaic (PV) power plant at the main campus of the Federal Polytechnic Mubi (FPM) in north-eastern Nigeria. A photovoltaic power plant converts solar radiation into electricity that can be used as a source of electrical power to meet the daily energy requirements of homes, equipment, and all tertiary institutions. RETScreen Expert software was used to evaluate the techno-economic and environmental sustainability of installing a grid-connected PV power plant. The research results revealed that with an annual solar radiation of 5.74 kWh/m2/day, the maximum annual energy production was estimated to be 1,550.98 MWh. It was discovered that the maximum energy production in March was 146.89 MWh. The project’s profitability and economic sustainability were determined with a good internal rate of return (IRR) of 11.9% and a positive net present value (NPV) of $681,164. The proposed PV power plant has a simple payback period of 11.4 years. The maximum greenhouse gas (GHG) emission reduction is 670.9 tCO2, equivalent to 61.7 ha of forest-absorbing carbon emissions.

Despite the low local energy access rates, Africa is considered a key player in the global energy transition due to its large supply of fossil fuels and a large reserve of critical minerals essential for manufacturing renewable energy components in the energy sector and storage devices in the transportation and electronics sectors. But building a sustainable society at all levels across nations would only come when there exists a just and inclusive energy transition based on the idea of “leave no one behind”. While many African countries have embarked on ambitious and transformative transition strategies, and many energy projects classified as “clean” have economic, environmental, and social implications that jeopardize the wellbeing of those already vulnerable to the impacts of climate change. This paper explores the policy implications of the just transition to ensure that efforts to steer Africa towards a lower carbon future are supported by fair, equity, and justice considerations. Our analyses provide valuable evidence for considering a just transition in Africa that will not exacerbate the current socio-economic challenges the region is facing but will support sustained poverty reduction and the achievement of faster economic growth. Our findings show that the African continent’s multiple challenges of energy security, economic growth, and affordable access must feature in its clean energy transition. We draw conclusions that an incremental transition emphasizing low-carbon development is the most feasible and pragmatic approach to transform the region’s economy and address climate change challenges.

The recent use of hybrid renewable energy systems (HRESs) is considered one of the most reliable ways to improve energy access to decentralized communities because of their techno-economic and environmental benefits. Many distant locales, such as camps in war-torn nations, lack basic necessities like power. This study proposes a remedy for power outages in these areas; by designing an HRES and a control system for monitoring, distributing, and managing the electrical power from sustainable energy sources to supply the load. Hence, providing affordable, reliable, and clean energy for all (Sustainable Development Goal 7). In this study, the feasibility and techno-economic performance of an HRES for a refugee camp was evaluated under load following (LF), cycle charging (CC), and predictive control strategy (PS). The optimization results revealed that the PS was the most suitable, as it had the lowest cost and was more eco-friendly and energy-efficient. The predictive control strategy had a 48-h foresight of the load demand and resource potential and hence could effectively manage the HRES. The total net present cost (NPC) for the electrification of this refugee camp was $3,809,822.54, and the cost of electricity generated for every kWh is $0.2018. Additionally, 991,240.32 kg of emissions can be avoided annually through the hybridization of the diesel generator under the PS.

The COVID-19 pandemic brought tremendous pressure to the African continent's health sector, particularly in rural areas. Rural healthcare facilities experienced severe energy shortages due to the influx of Covid-19 patients, which strained their operating capacities. These facilities usually rely on diesel engines, and this unidirectional approach limited governments' vision in resolving the energy crisis. This paper aims to develop a hybrid energy system (HES) that combines alternate energy sources available at a rural healthcare centre in northern Nigeria and conduct a techno-economic analysis of the viability of such systems. The energy potential of available energy resources at the target location and comparison of various HES configurations were estimated with HOMER Pro software to determine the most feasible choices. These choices were analyzed for technical, financial, and environmental viability using RETScreen Expert. Due to an abundance of solar energy, low diesel cost, and sufficient wind energy potential, the results show PV – Diesel and Wind – Diesel system HES configurations as the only practical choices. Techno-economic analysis indicates that the PV – Diesel HES produces annual savings of $30,583 with a Net Present Value (NPV) of $390,949 compared to $15,174 and $193,980 for the Wind – Diesel configuration. Further analysis solidifies the PV-Diesel HES as the best choice with a payback period of 1.3 years, 75 tons of CO2 emission reduction, and annual savings of $30,583 compared to the initial diesel energy system.

This paper presents a feasibility analysis of the technical, environmental, and economic sustainability of an existing mini-grid technology system in Nigeria. The study investigates the cost and other operational parameters of the Gbamu-Gbamu solar–battery–diesel hybrid mini-grid, specifically the 85 kWp solar PV installation in the Ijebu East Local Government area of Ogun state. Situated within the Owo forest in South-West Nigeria, the mini-grid aims to reduce the effects of global warming and promote sustainable technological development in rural communities by increasing energy access through renewable sources. To assess the system’s viability, this research utilized RETScreen Expert software to validate the techno-economic and environmental sustainability of the installed mini-grid solar–PV–battery–diesel system in the region. Climatic data for the study were obtained from the National Aeronautics and Space Administration (NASA). The results demonstrate that the system is economically feasible and environmentally viable, as indicated by the positive net present value (NPV) and an average monthly irradiance of 4.78 kW/h/m2. Furthermore, the system achieved a 92.9% reduction in GHG emissions, provided a reasonable payback period of four years, and enabled a yearly electricity export of 203 MWh. These findings highlight the system’s potential to enhance energy access and mitigate climate change.

This paper presents the technical and economic analysis of a solar–wind electricity generation system to meet the power requirements of a rural community (Okorobo-Ile Town in Rivers State, Nigeria) using the Renewable—energy and Energy—efficiency Technology Screening (RETScreen) software. The entire load estimation of the region was classified into high class, middle class, and lower class. Two annual electricity export rates were considered: 0.1 USD/KWh and 0.2 USD/KWh. The results from the proposed energy model comprising a 600 kW PV system and a 50 kW wind system showed that with a USD 870,000 initial cost and USD 9600 O&M cost, the annual value of the electricity generated was 902 MWh. The simple payback was 5.1 years with a net present value of USD 3,409,532 when 0.2 USD/KWh was used as the annual export rate instead of 10.8 years for simple payback and an NPV of USD 1,173,766 when 0.1 USD/KWh was used. Thus, there is a potential to install a wind–solar system with average weather conditions of 4.27 kWh/m2/d for the solar irradiance and 3.2 m/s for the wind speed at a 10 m hub height using a rate of 0.2 USD/KWh as the electricity export rate.

Since the increase in the emission of various Volatiles Organic Compounds, gas and formaldehyde gas have had a harmful effect on the human body, and gas sensors that can measure those gases were fabricated in this study. After Pt coating was performed on the alumina substrate, Zn seed layers were fabricated. Nanostructures were formed through sonochemical synthesis by varying the ratio of ZnO and TiO2. Thereafter, the reactivity and recovery properties were compared and evaluated according to the concentrations of formaldehyde and toluene gas. The ZnO(99%)-TiO2(1%) gas sensor showed meaningful selectivity of about 40% or more at a concentration ranging from 5 to 20 ppm (high concentration) of formaldehyde and toluene gas, and showed a low selectivity of about 5% or more for a concentration ranging from 0.1 to 1 ppm (low concentration) of formaldehyde and toluene gas. This sensor can be optimized to have a meaningful selectivity of formaldehyde gas compared to other Volatiles Organic Compounds gases by optimizing the ZnO-TiO2 nanostructure.

Korean old residential apartments built over many decades were constructed without proper energy efficiency measures. This makes the energy performance of existing buildings to be very poor when compared with the energy performance of new buildings. This study presents the use of a 12 years gas consumption data to evaluate the energy performance of an existing residential building in Korea by carrying out Measurement and Verification (M&V) analysis using RETScreen Expert software after building retrofit. From the analysis, a total of 249 Giga Joules (GJ) of Liquefied Natural Gas (LNG) was consumed at the rate of 0.17 GJ/day on an average from the year 2011 to 2014 with the peak consumption in the year 2013 costing the occupant a sum of $5,401. Also, the net energy savings was 64GJ as of June 2019 after the installation of an Energy Conservation Measures (ECMs) with the highest between the year 2016 and 2018. An energy forecast for the year 2020 indicates that 2.71 (tCO2) GHG emissions will be reduced as a result of the energy that will be saved from the 54 Giga Joule (GJ) fuel consumed. Finally, energy efficiency was attained and this reduced the resident doubt on the benefits of energy efficiency measures.

The Pacific region of Colombia is known to be one of the most vulnerable to changes in precipitation patterns. A study was conducted using standardized precipitation index (SPI) analyses to understand the potential changes in precipitation in this region during the 21st century. The analyses were conducted using historical precipitation data from 1950 to 2005 and projected precipitation data from 2022 to 2100 under the Coordinated Regional Climate Downscaling Experiment (CORDEX) climate scenarios (RCP 4.5 and RCP 8.5). The results of the study showed that compared to historical data, SPI3 precipitation in this region is predicted to increase by 2040 under both climatic scenarios. However, in the 2041–2070 period, the region is expected to be wetter under RCP 8.5, although the difference between the two scenarios was not statistically significant. Similarly, SPI 6 precipitation is predicted to increase in the 2022–2040 and 2071–2100 periods under both scenarios. SPI 12 precipitation is also predicted to increase in the 2022–2040 period under RCP 4.5. In the 2041–2070 period, dryness is predicted to be more frequent under RCP 4.5, and wetness is predicted under RCP 8.5. The findings of this study can help in determining the most pertinent reference periods and computation time increments for evaluating the effects of future climate change on agricultural production and food security in the Pacific region of Colombia. It suggests that changes in precipitation patterns are likely to occur in the coming decades, which may significantly impact crop growth, water availability, and other aspects of agricultural production.

Owing to the increasing construction of new buildings, the increase in the emission of formaldehyde and volatile organic compounds, which are emitted as indoor air pollutants, is causing adverse effects on the human body, including life-threatening diseases such as cancer. A gas sensor was fabricated and used to measure and monitor this phenomenon. An alumina substrate with Au, Pt, and Zn layers formed on the electrode was used for the gas sensor fabrication, which was then classified into two types, A and B, representing the graphene spin coating before and after the heat treatment, respectively. Ultrasonication was performed in a 0.01 M aqueous solution, and the variation in the sensing accuracy of the target gas with the operating temperature and conditions was investigated. As a result, compared to the ZnO sensor showing excellent sensing characteristics at 350 °C, it exhibited excellent sensing characteristics even at a low temperature of 150 °C, 200 °C, and 250 °C.

In this study, graphene oxide (GO) was coated on the surface of a large-area polystyrene film using spray coating. To analyze the possibility of developing a large-area cell culture vessel from this material, the mechanical properties of the coated surface as well as the cell compatibility and cell proliferation in the vessel were evaluated. Step measurements confirmed a curve of 100 nm or larger on the cell culture vessel surface. The surface was composed of GO (as determined from Raman spectroscopy) and its measured transmittance was ~90% or higher. The coated surface was rendered hydrophilic with an increase in surface energy. Although the cells hardly grew on the general polystyrene film, they attached and proliferated on the polystyrene film coated with GO. Zero cytotoxicity was reported, particularly in the sample that was spray-coated three times at 93.75 mm/s. Note that the cell viability was 1.43 times higher than that in the conventional cell culture vessel. Economic and efficient large-area cell culture vessels can be developed if the GO coating establishes an appropriate surface roughness and surface energy.

The sensing characteristics of toluene gas are monitored by fabricating ZnO nanorod structures. ZnO nanostructured sensor materials are produced on a Zn film via an ultrasonic process in a 0.01 M aqueous solution of C6H12N4 and Zn(NO3)2∙6H2O. The response of the sensors subjected to heat treatment in oxygen and nitrogen atmospheres is improved by 20% and 10%, respectively. The improvement is considered to be correlated with the increase in grain size. The relationship between the heat treatment and sensing characteristics is evaluated.

This paper focuses on the techno-economic feasibility and sustainability of a PV/wind/diesel hybrid system designed for decentralized power supply. Several designs have been studied for the hybrid system by varying the PV slope and wind turbine hub height under different dispatch strategies to supply the load. For each design, the power system has been optimized to determine the maximum electrical output at a low cost. Sensitivity analyses have been performed to evaluate operational risk in the actual operation as well as the cost-effectiveness of the proposed system. As a final remark, the sustainability of the proposed hybrid energy system has been analyzed based on some key indicators to understand the implications of a design choice on electrical production, CO2 emission and cost of energy. Our results show that for a projected period of 25 years, the selected hybrid power system for electrification of a housing estate will cost 10.2 million USD for a daily load of 4876.5 kWh, and the cost for every kWh of electricity generated is $0.4574. Results also show that the hybridization of the standard diesel generating system increased the reliability and cost-effectiveness of the power system, saving $0.316 for every kWh of electricity generated, with about 1,521,310 kg of CO2 emission avoided annually.

Pressure of the kinetic zone is an essential factor for making defect-free castings in lost-foam casting process. The extremely high pressure causes many problems, such as reducing the melt velocity and inclusion of residual decomposition of the pattern in the castings, and very low pressure causes sand collapse. Therefore, the minimum gas pressure for preventing sand collapse is required. When the minimum gas pressure can be predicted, computer simulation becomes possible. Successful computer simulations can help reduce the number of trials and the lead time while designing new casting products. A preliminary sand experiment was conducted to predict the gas pressure and reduce the number of actual casting experiments. In this preliminary sand experiment, compressed air was used instead of gas in the kinetic zone. A new mathematical equation was proposed from the results of the preliminary sand experiment. The void ratio of the sand effect on the minimum gas pressure was included in the equation. An actual casting experiment was conducted by melting nodular cast iron to verify this equation. In the actual casting experiment, pressure of the kinetic zone in front of the metal tip was directly measured. The results obtained from the preliminary sand experiment and the actual casting experiment validated the equation.

Currently, the world is actively responding to climate change problems. There is significant research interest in renewable energy generation, with focused attention on solar photovoltaic (PV) generation. Therefore, this study developed an accurate and precise solar PV generation prediction model for several solar PV power plants in various regions of South Korea to establish stable supply-and-demand power grid systems. To reflect the spatial and temporal characteristics of solar PV generation, data extracted from satellite images and numerical text data were combined and used. Experiments were conducted on solar PV power plants in Incheon, Busan, and Yeongam, and various machine learning algorithms were applied, including the SARIMAX, which is a traditional statistical time-series analysis method. Furthermore, for developing a precise solar PV generation prediction model, the SARIMAX-LSTM model was applied using a stacking ensemble technique that created one prediction model by combining the advantages of several prediction models. Consequently, an advanced multisite hybrid spatio-temporal solar PV generation prediction model with superior performance was proposed using information that could not be learned in the existing single-site solar PV generation prediction model.

Global wheat demand is expected to continue to increase due to the projected increase in the World’s population but regrettably, wheat yield is expected to decrease due to the progressively changing climate. Although the effects of temperature, soil moisture and nutrient absorption on the yield of wheat have been studied extensively to address the threats posed by climate change on food security, the combined effects of these factors have been studied to a lesser extent. This study thus aims to investigate the interactive effects of different regimes of fertilizer and soil moisture on the yield and amino acid composition of wheat. Twelve treatments under different regimens of soil moisture and fertilizer, replicated ten times in a randomized block design were considered in the greenhouse and in the field. The study reveals that variation in each factor had a significant effect on wheat but soil moisture was the principal factor controlling yield and protein accumulation. Application of organic fertilizer to wheat increased amino acid accumulation when the average temperature was at 18oC, with minimum temperature (Tmin) and maximum temperature (Tmax) of -6oC and 42oC respectively. However, application of inorganic fertilizer to wheat enhanced amino acid accumulation when the average daily temperature was at 8oC, with Tmin and Tmax of -10oC and 26oC respectively. Our results also show that a decrease in soil moisture from 100% to 30% in the greenhouse improved the quantity of amino acid in the grain by 26.4% and 56.8% for organic and inorganic treatments respectively. Also, grain amino acid concentration increased by 16.6% and 4.76% when soil moisture dropped from 100% to 30% for the organic and inorganic treatments in the field respectively.

Body fluids are often used as specimens for medical diagnosis. With the advent of advanced analytical techniques in biotechnology, the diagnostic potential of saliva has been the focus of many studies. We recently reported the presence of excess salivary sugars, in patients with Alzheimer's disease (AD). In the present study, we developed a highly sensitive, cell-based biosensor to detect trehalose levels in patient saliva. The developed biosensor relies on the overexpression of sugar sensitive gustatory receptors (Gr5a) in Drosophila cells to detect the salivary trehalose. The cell-based biosensor was built on the foundation of an improved extended gate ion-sensitive field-effect transistor (EG-ISFET). Using an EG-ISFET, instead of a traditional ion-sensitive field-effect transistor (ISFET), resulted in an increase in the sensitivity and reliability of detection. The biosensor was designed with the gate terminals segregated from the conventional ISFET device. This design allows the construction of an independent reference and sensing region for simultaneous and accurate measurements of samples from controls and patients respectively. To investigate the efficacy of the cell-based biosensor for AD screening, we collected 20 saliva samples from each of the following groups: participants diagnosed with AD, participants diagnosed with Parkinson's disease (PD), and a control group composed of healthy individuals. We then studied the response generated from the interaction of the salivary trehalose of the saliva samples and the Gr5a in the immobilized cells on an EG-ISFET sensor. The cell-based biosensor significantly distinguished salivary sugar, trehalose of the AD group from the PD and control groups. Based on these findings, we propose that salivary trehalose, might be a potential biomarker for AD and could be detected using our cell-based EG-ISFET biosensor. The cell-based EG-ISFET biosensor provides a sensitive and direct approach for salivary sugar detection and may be used in the future as a screening method for AD.

Exhaled breath is a body secretion, and the sampling process of this is simple and cost effective. It can be non-invasively collected for diagnostic procedures. Variations in the chemical composition of exhaled breath resulting from gaseous exchange in the extensive capillary network of the body are proposed to be associated with pathophysiological changes. In light of the foreseeable potential of exhaled breath as a diagnostic specimen, we used gas chromatography and mass spectrometry (GC-MS) to study the chemical compounds present in exhaled breath samples from patients with Alzheimer’s disease (AD), Parkinson’s disease (PD), and from healthy individuals as a control group. In addition, we also designed and developed a chemical-based exhaled breath sensor system to examine the distribution pattern in the patient and control groups. The results of our study showed that several chemical compounds, such as 1-phenantherol and ethyl 3-cyano-2,3-bis (2,5,-dimethyl-3-thienyl)-acrylate, had a higher percentage area in the AD group than in the PD and control groups. These results may indicate an association of these chemical components in exhaled breath with the progression of disease. In addition, in-house fabricated exhaled breath sensor systems, containing several types of gas sensors, showed significant differences in terms of the normalized response of the sensitivity characteristics between the patient and control groups. A subsequent clustering analysis was able to distinguish between the AD patients, PD patients, and healthy individuals using principal component analysis, Sammon’s mapping, and a combination of both methods, in particular when using the exhaled breath sensor array system A consisting of eight sensors. With this in mind, the exhaled breath sensor system could provide alternative option for diagnosis and be applied as a useful, effective tool for the screening and diagnosis of AD in the near future.