Malaria risk mapping in the Sahel Region of Nigeria: A geospatial approach

Malaria remains a major public health challenge in Yobe State, Nigeria, with transmission patterns influenced by climatic, socio-economic and environmental factors. Understanding the spatial and temporal dynamics of malaria prevalence is crucial for effective intervention and policy planning. This study examined the trends, seasonality, and spatial variations in malaria prevalence across different ecological zones in Yobe State, providing insights into the impact of climate variability and other risk factors on malaria transmission. A geospatial approach was employed, utilizing malaria incidence data from Yobe State Government’s Epidemic Data Repository and health facilities across three ecological zones: the Sudan Savanna Zone (SuSZ), the Sahel Savanna Zone (SaSZ), and the Transition Zone (TZ). Temporal trends were analyzed using regression models, while spatial patterns were examined through hotspot analysis to identify high-burden areas. Findings revealed significant spatial and temporal variations in malaria prevalence. While malaria incidence showed no strong temporal trend in SaSZ (R² = 0.06) and TZ (R² = 0.04), Sudan Savanna Zone exhibited a notable increasing trend (R² = 0.77), suggesting a worsening malaria burden. Seasonal peaks in malaria cases aligned with the rainy season, emphasizing the role of climate in transmission. Spatial analysis identified persistent malaria hotspots in urban centers such as Gashua, Damaturu and Fika, where high population density and environmental factors contribute to transmission. These results underscore the need for climate-informed malaria control strategies, including enhanced surveillance, early warning systems, and targeted interventions in high-risk areas. Sustainable malaria control efforts must integrate climate predictions, improved healthcare access, and promote community engagement to prevent periodic resurgence and ensure long-term elimination goals are met

Circular economy in supply chain sustainability: From bibliometric analysis to conceptual model

This study aims to analyze research trends on the circular economy and supply chain sustainability using a bibliometric approach and to develop a conceptual model that can guide the implementation of circular economy practices. Data were obtained from the Scopus database and analyzed to identify publication trends, scientific contributions, and collaborations among researchers. The results show a significant increase in research related to the circular economy since 2020, especially in the manufacturing and technology sectors, with a primary focus on recycling, reuse, and remanufacturing as key elements of supply chain sustainability. The developed conceptual model emphasizes the importance of integrating technologies such as the Internet of Things (IoT), blockchain, and Big Data, alongside  the Triple Bottom Line approach, that includes economic, environmental, and social aspects. Collaboration among stakeholders, governments, and consumers is also identified as an important factor in accelerating the adoption of the circular economy. This study contributes to the development of circular economy implementation strategies across various sectors and highlights future research opportunities, such as circular bioeconomy and green innovation. The proposed model is expected to serve as a guide for companies and policymakers in strengthening supply chain sustainability.

Enhancing thermal and visual comfort through sun shading and glazing: A case study of Pusgiwa building, Universitas Indonesia

This study examines the relationship between the building envelope and the indoor environment quality, with a specifical focus on visual and thermal comfort. Factors contributing to visual comfort include illuminance and light distribution, while thermal comfort is primarily influenced by air temperature. The research centers on the north façade of the Educational Building at the University of Indonesia, Pusgiwa, particularly the 4th floor classroom, to evaluate how the sun-shading system and glazing materials influence lighting and temperature conditions. By analyzing the existing design and materials, the study investigates potential interventions to enhance illuminance, daylight availability, and operative temperature within the classroom. The methodology includes calculating solar angles and simulating various sun-shading and glazing material scenarios using Rhinoceros and Grasshopper software. The results indicate that installing horizontal, multi-layered overhang shading with optimal spacing can increase daylight availability and reduce indoor air temperature. Furthermore, the use of materials with a low U-Value and Solar Heat Gain Coefficient (SHGC), such as Low-E double glazing, is recommended to further improve indoor environmental quality. These findings provide valuable insights and recommendations for enhancing visual and thermal comfort in both existing and future buildings at Pusgiwa and similar facilities

Factors influencing food waste behavior: A study on college students in Medan City, Indonesia

One of the world’s environmental problems is food waste. This problem is closely related to Sustainable Development Goals (SDGs), particularly the goal on sustainable production and consumption. Food waste affects not only environmental aspects but also the social and economic aspects, it is often driven by individual behavior. This study aims to calculate the percentage of food waste based on nutrition classification and to analyze factors influencing the food waste behavior. A survey was conducted through face-to-face interviews with 134 college students. The variables examined included socioeconomic and behavioral factors. Binary logistic regression was applied for data analysis. This results show carbohydrates-rich foods such as rice, noodles and bread were the most commonly wasted items among college students in Medan. Furthermore, the factors influencing food waste behavior were dining out behavior, promotions or discounts, food expenditure, diet programs and eating frequency. Taking leftovers home and reheating them were the most common practices used by students to reduce food waste. In addition, the government should formulate policies and regulations on food waste management to help reduce food waste in Medan City

Effect of ammonium/phosphate molar ratio on struvite production via electrolysis using a sacrificial magnesium anode

Excessive ammonium and phosphate levels in aquatic environments potentially cause eutrophication, leading to water quality imbalance, algal blooming, and disturbance of biodiversity status. Electrolysis using a sacrificial magnesium anode effectively removes and recovers ammonium and phosphate, producing struvite (MgNH4PO4.6H2O). The present study investigated the optimum current density and the effect of the ammonium/phosphate molar ratio on struvite production. The current density was controlled at 10, 50, and 100 mA/cm2. An artificial wastewater containing [NH4+]:[PO43-] in a molar ratio of 1:10, 1:1, and 10:1 was used as the test solution. The optimum current density was determined as 50 mA/cm2. The ammonium and phosphate reduction ratios at a 1:1 molar ratio was approximately 46.91% and 74.26%, respectively. Increasing the ammonium molarity in the test solution to 10:1 increased the phosphate reduction ratio to 96.38% while decreasing the ammonium reduction ratio to 26.28%. The maximum precipitation of 4.1914 g was generated at a molar ratio of 10:1 with a specific energy consumption of 0.011 Wh/mg-P, out of the three ammonium/phosphate molar ratio variations. Microscopes and SEM-EDS were used to characterize the precipitates produced, and Visual MINTEQ 3.1 was then used for modeling

Comparative analysis of woody species diversity in church, community, and national park forests in Ethiopia: Review

Forest resources in Ethiopia are facing intensive degradation and deforestation due to agricultural land expansion, overgrazing, urbanization, invasive species, and climate change. Due to this, small isolated forest patches are left in different parts of the country through legal protections and religious sanctions. The study aimed to examine the country's highest woody species diversity among church, community, and national park forests. The remnant forest patches in Ethiopia were categorized into church, community, and national park forests based on ownership and management objectives of the forest. The diversity data were collected from a detailed review of published and unpublished scientific reports. The variation in species richness, evenness, and Shannon diversity among forest categories were analyzed and tested using ANOVA. The mean Shannon diversity of church, community, and national park forests were 2.95, 2.88, and 3.13, respectively. These forest categories have a considerable role in species diversity in the country. However, the variation was statistically insignificant at a 95% confidence interval. Hence, each forest category plays a comparable role in woody species diversity in the country

Solar charging controller using DC-DC buck converter with cascaded PI controller for a sustainable renewable energy system

The renewable energy system (RES) has recently become hot topic due to its unlimited, green energy potential, and the maturity of its technology. A solar charging controller (SCC) is required to regulate parameters for the battery and is an essential component for sustainable and renewable energy usage. An SCC based on a DC-DC Buck converter with cascaded proportional-integral (PI) controller is used in the system for managing the current and voltage loops, thereby preventing battery overcharging. The control parameters are determined using the Ziegler-Nichols method based on the reaction curve. A first -order system is employed due to the open-loop responses show no overshoot and oscillations. MATLAB software is used for both simulation and controller design. Simulations are conducted to validate the proposed SCC with the cascaded controller. Variations in the state of charge (SoC) are presented in two cases: without and with the controller. The SoC is set 20%, 50%, and 95%. A high SoC percentage indicates that the battery is near the full capacity, whereas a low percentage indicates that battery is near empty. Using the cascaded controller, both current and voltage responses at different SoC levels demonstrate satisfactory performance, including rapid transient responses, minimal overshoot, small ripples, and robustness

Technical stakeholders' perspective of solar photovoltaic system failure in Sub-Saharan Africa: The case of Ghana

In many parts of sub-Saharan Africa, grid-connected electricity is unreliable and frequently unavailable in rural locations. Alternative electricity-generation fossil-fuel sources are prohibitive. Solar energy photovoltaic systems have great potential in bridging the energy gap in electricity off-grid locations in sub-Saharan Africa and contribute to the region’s energy portfolio at utility and/or domestic levels. Most installed PV systems in sub-Saharan Africa have often not achieved their anticipated functionality and/or fail frequently. Take-up of PV systems consequently remains low, with long pay-back times. In this study, we have investigated the barriers and challenges associated with PV system operation and probable causes of failure of installed systems within the sub-Saharan Africa region from the perspective of technical stakeholders. We undertook a broad consultation of technicians (installers), engineers, project supervisors, and other technical stakeholders via questionnaires and interviews in a typical sub-Saharan African setting, namely Ghana. Our results show that component quality, cost, availability, and customer preferences are dominant factors considered by the technical stakeholders in component selection during the planning and execution of PV projects. The survey analysis revealed that inverters and batteries are components that account for the most malfunctioning and failures in installed PV systems, while PV panels account for the least. Low product quality, user errors, natural/environmental incidents, and poor sizing/installation errors are identified as key causes of components’ failure

Navigating a sustainable agricultural economy in Indonesia's new capital city

One of the Sustainable Development Goals (SDGs) under the second pillar emphasizes to aim to “End Hunger, Achieve Food Security and Improved Nutrition, and Promote Sustainable Agriculture”. At the same time, Indonesia is relocating its capital city to Ibu Kota Nusantara (IKN), and the demand for agricultural commodities is increasing in line with population growth. Referring to this phenomenon, this article examines the relationship between labor, employment opportunities, loan value, and entrepreneurship with expenditure and per capita income, and economic growth in the agricultural sector within the IKN region. Secondary data were obtained from government agencies for the period 2015–2023 and analyzed using time-series regression. The empirical findings highlight three important points. First, labor, entrepreneurship, and per capita expenditure positively influence economic growth. Second, these variables also have a positive impact on per capita income. Third, employment, loan value, per capita income, and economic growth are positively associated with per capita expenditure. This case study suggests that stakeholders, including policy makers, academics, businesses, and local communities, should develop more inclusive agricultural economic policies. In the long-term, such approach could help refine and expand existing conceptual frameworks

Sustainable building: Achieving thermal comfort in hot and humid climate using building performance simulation

The scientific community has established a clear link between the built environment and various environmental problems. Various strategies have been implemented to mitigate the negative impacts of buildings and to address broader environmental challenges. One such strategy is the adoption of sustainable building practices. Among the factors contributing to the environmental impacts of buildings, efforts to achieve thermal comfort play significant role. Particularly due to the energy consumption involved. At the same time, thermal comfort is also a critical factor influencing human productivity, including academic performance. Comfortable learning environments are known to enhance students’ learning outcomes. This research presents a case analysis conducted at State Elementary School 91 Sipatana, Gorontalo City, Indonesia. Measurements were carried out on December 24, 2022, from 06.00 to 18.00. Room temperature was recorded using an Elitech GSP-6 data logger, and further simulations were carried out using Ladybugs and Honeybees. The purpose of this study is to evaluate building performance in achieving thermal comfort by considering solar radiation exposure, roof surface temperature, room temperature, and Predicted Mean Vote (PMV) values. Comparisons were made across different building materials, including variation in roofing, wall types, and ventilation systems. The wall in the existing structure are composed of concrete with a fiber wall. The findings highlight the impact of roofing materials, wall construction, and ventilation on the PMV, roof surface temperature, and indoor air temperature. Based on-site measurements, the average classroom temperature was 30.5°C. Among the simulation configurations, Model 3 which featured a metal roof with a cool roof technology, concrete walls, and added ventilation demonstrated the best thermal performance. It maintained a roof surface temperature just above 25°C and an indoor air temperature close to 30°C, showing the effectiveness of cool roof technology and adequate ventilation in reducing heat accumulation