Resources

23 pages, 19178 KiB

Open AccessArticle

High Field Strength Element (HFSE) and Rare Earth Element (REE) Enrichment in Laterite Deposit of High Background Natural Radiation Area (HBNRA) of Mamuju, West Sulawesi, Indonesia

by I Gde Sukadana, Sulaeman, Heri Syaeful, Frederikus Dian Indrastomo, Tyto Baskara Adimedha, Roni Cahya Ciputra, Fadiah Pratiwi, Deni Mustika, Agus Sumaryanto, Muhammad Burhannudinnur, Rr Arum Puni Rijanti, Puji Santosa and Susilo Widodo

Resources 2025, 14(5), 84; https://doi.org/10.3390/resources14050084 - 20 May 2025

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Abstract

The Mamuju region in West Sulawesi, Indonesia, is a High Background Natural Radiation Area (HBNRA) characterized by a significant enrichment of high field strength elements (HFSEs) and rare earth elements (REEs) within its lateritic deposits. This study investigates the geochemical behavior, mineralogical distribution, [...] Read more.

The Mamuju region in West Sulawesi, Indonesia, is a High Background Natural Radiation Area (HBNRA) characterized by a significant enrichment of high field strength elements (HFSEs) and rare earth elements (REEs) within its lateritic deposits. This study investigates the geochemical behavior, mineralogical distribution, and enrichment processes of HFSEs and REEs in lateritic profiles of drill cores and surface samples derived from alkaline volcanic rocks. The mineralogy and geochemical content of HFSEs and REEs in the alkaline bedrocks indicate its potential to become a source of lateritic enrichment. An intense lateritic weathering process leads to the residual accumulation of HFSEs and REEs, particularly in B-horizon soils, where clay minerals and Fe–Al oxides are crucial in element precipitation. Moreover, groundwater redox conditions are a key factor for uranium precipitation in the lateritic profile. The findings provide insight into the potential of lateritic weathering as a natural mechanism for HFSE and REE concentration, contributing to the broader understanding of critical metal resources in Indonesia. These insights have implications for sustainable resource exploration and environmental management in areas with high natural radiation exposure. Full article

(This article belongs to the Special Issue Consideration of Critical and Strategic Raw Materials in Life Cycle Management)

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13 pages, 761 KiB

Open AccessArticle

Tropical Fruit Wastes: Physicochemical Characterization, Fatty Acid Profile and Antioxidant Capacity

by Mariana Ferreira dos Santos, Beatriz Pereira de Freitas, Jaqueline Souza de Freitas, Luane Souza Silva Lage, Alex Aguiar Novo, Claudete Norie Kunigami, Eliane Przytyk Jung and Leilson Oliveira Ribeiro

Resources 2025, 14(5), 83; https://doi.org/10.3390/resources14050083 - 20 May 2025

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Abstract

Wastes resulting from the depulping of tropical fruits such as siriguela (Spondias purpurea), umbu (Spondias tuberosa), and juçara (Euterpe edulis) can be used as a source of bioactive compounds and nutrients. Therefore, the aim of this work [...] Read more.

Wastes resulting from the depulping of tropical fruits such as siriguela (Spondias purpurea), umbu (Spondias tuberosa), and juçara (Euterpe edulis) can be used as a source of bioactive compounds and nutrients. Therefore, the aim of this work was to chemically characterize the flours of siriguela seeds and peels (FSSs and FSPs), umbu seeds and peels (FUSs and FUPs), umbu pulp refine cake (FUC), and defatted juçara pulp refine cake (FJC) based on their proximate composition and mineral content, fatty acids, total phenolic content (TPC) and antioxidant capacity (ABTS^•+, DPPH^•, and FRAP). The results were expressed on a dry basis. The FJC had the highest lipid and protein percentage (10% and 31%, respectively), while for carbohydrates; FUS samples had the highest value (80%). FSSs presented the highest levels of Ca (239.7 mg 100 g⁻¹), Mg (183.3 mg 100 g⁻¹), and FSP of K (1403.9 mg 100 g⁻¹). Regarding the fatty acid profiles, palmitic acid (C16:0) was found as the main fatty acid in FSSs (28.87%), FSPs (69.31%), and FUC (45.68%), while oleic acid (C18:1) was found as the main fatty acid in FUSs (32.63%), FUPs (48.24%), and FJC (61.58%). The FUP sample exhibited the highest antioxidant potential (1852.81 mg GAE 100 g⁻¹, 130 µmol Trolox g⁻¹, 131 µmol Trolox g⁻¹, and 590 µmol Fe²⁺ g⁻¹ by TPC, ABTS^•+, DPPH^•, and FRAP, respectively). As the first comparative study of these specific fruits wastes, the results showed that their flours are promising sources of nutrients and bioactive compounds. In addition, their use can contribute to the circular economy and Sustainable Development Goals (SDGs) 2 and 12 of the 2030 Agenda. Full article

(This article belongs to the Special Issue Resource Extraction from Agricultural Products/Waste: 2nd Edition)

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19 pages, 10793 KiB

Open AccessArticle

Antioxidant and Physico-Structural Insights of Walnut (Juglans regia) and Hazelnut (Corylus avellana L.) Shells: Implications for Southern Chile By-Product Valorization

by Carlos Manterola-Barroso, Karina Godoy Sanchez, Erick Scheuermann, Daniela Padilla-Contreras, Filis Morina and Cristian Meriño-Gergichevich

Resources 2025, 14(5), 82; https://doi.org/10.3390/resources14050082 - 20 May 2025

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Abstract

Considerable amounts of agro-industrial by-products are discarded every year. Moreover, these represent an interesting source of phenolics, cellulose and lignin, in addition to useful compounds such as antioxidants. However, these compounds may be affected by external factors such as genotype, locality and productive [...] Read more.

Considerable amounts of agro-industrial by-products are discarded every year. Moreover, these represent an interesting source of phenolics, cellulose and lignin, in addition to useful compounds such as antioxidants. However, these compounds may be affected by external factors such as genotype, locality and productive season, increasing or decreasing the antioxidant potential of by-products. In this study, hazelnut (Corylus avellana L.) and walnut (Juglans regia L.) nutshells were investigated for their fiber content and antioxidant capacity as valorized by-products in this industry. The determination of oxygen radical absorbance capacity (ORAC), total phenolic content (TPC) and color difference was performed using hazelnut and walnut shells collected from orchards located in Southern Chile during three consecutive seasons (2020/21, 2021/22 and 2022/23). The ORAC in nutshells showed the highest values in both species for the season 2020/21 (3217 and 4663 µmol TE g DW⁻¹ for hazelnut and walnut), whereas the variability in consecutive seasons was lower for hazelnut than for walnut. The TPC in hazelnut shells was positively correlated with L* (R: 0.883) and ΔE (r = 0.924) during the 2020/21 season and with L* for 2022/23 (r = 0.907). On the other hand, the ORAC was negatively correlated with L* (r = 0.922) in 2021/22. In addition, the morphological and structural features of both nutshells examined by scavenging electron microscopy (VP-SEM) and confocal scavenging laser microscopy (CSLM) revealed differential tissue distribution and accumulation patterns of both cellulose and lignin. In addition, photo-colorimetric values were determined for both shells and corresponding seasons, and non-significant differences were found for both shells and among seasons. Finally, our results provide new insights into the physicochemical characteristics of these two types of nutshells as valorized by-products, considering their antioxidant properties as residual materials derived from this agroindustry. Full article

(This article belongs to the Special Issue Alternative Use of Biological Resources)

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23 pages, 2206 KiB

Open AccessArticle

Assessment of the Agroecological Transition of Farms in Central Tunisia Using the TAPE Framework

by Inès Gharbi, Fatma Aribi, Hassen Abdelhafidh, Nouha Ferchichi, Lamia Lajnef, Wael Toukabri and Mohamed Jaouad

Resources 2025, 14(5), 81; https://doi.org/10.3390/resources14050081 - 19 May 2025

Viewed by 245

Abstract

In Tunisia, the agricultural sector faces multiple challenges that affect both productivity and farmers’ livelihoods. Although agroecology is increasingly recognized as a pathway to sustainable agriculture, the extent of its adoption by farmers remains unclear. This study assesses the agroecological performance of 50 [...] Read more.

In Tunisia, the agricultural sector faces multiple challenges that affect both productivity and farmers’ livelihoods. Although agroecology is increasingly recognized as a pathway to sustainable agriculture, the extent of its adoption by farmers remains unclear. This study assesses the agroecological performance of 50 farms in the Sbikha delegation of the Kairouan governorate (Central Tunisia), using the Tool for Agroecological Performance Evaluation (TAPE), developed by the FAO. This tool assesses how existing cropping systems align with the 10 principles of agroecology and explores their potential for further transition. The results reveal a modest level of agroecological adoption, averaging only 41%. Several factors influence this outcome, including limited farmer knowledge and technical capacity, a weak institutional and organizational framework, and low diversification of cropping systems. Furthermore, three types of farms were identified based on their production systems: farms specializing in fruit trees, farms specializing in cereal and vegetable crops, and farms specializing in olive and vegetable crops. Among these, fruit tree farms exhibit a higher level of agroecological transition, averaging 51%. This increased diversification enhances resilience to market fluctuations. To accelerate the agroecological transition, several key measures should be implemented. Updating land property titles would improve access to credit by enabling farmers to provide the necessary guarantees. Additionally, targeted training programs and awareness-raising initiatives could strengthen technical capacities, thereby facilitating the adoption of agroecological practices. These interventions would enhance farmers’ economic resilience, support sustainable agricultural production, and promote equitable rural development. Full article

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22 pages, 3818 KiB

Open AccessArticle

Application of Machine Learning Algorithms to Predict Gas Sorption Capacity in Heterogeneous Porous Material

by Tasbiha Ibad, Syed Muhammad Ibad, Haylay Tsegab and Rabeea Jaffari

Resources 2025, 14(5), 80; https://doi.org/10.3390/resources14050080 - 16 May 2025

Viewed by 152

Abstract

Shale gas is a clean and effective energy source that plays a big part in the transition from high-carbon to low-carbon energy, serving as a link for the growth of low-carbon energy in the future. Since shale rock is a heterogeneous porous material, [...] Read more.

Shale gas is a clean and effective energy source that plays a big part in the transition from high-carbon to low-carbon energy, serving as a link for the growth of low-carbon energy in the future. Since shale rock is a heterogeneous porous material, the best production strategy is determined by a precise assessment of geological gas-in-place. Therefore, the economic and technical foresight of the production operations depends on the estimation of the adsorbed gas amount in shale resources. The isotherm curves of shale gas derived in this study were classified as type 1 isotherms, which indicates the presence of micropores in these samples. In this work, XGBoost (extreme gradient boosting) and ANN (artificial neural network) optimized with ABC (artificial bee colony) and PSO (particle swarm optimization) have been proposed to learn and then predict the methane sorption capacity (MSC) in shale based on total organic carbon (TOC), temperature, pressure, and moisture as input variables, with the gas adsorption amount of shale as the output. Statistical and graphical methods were used to compare the experimental results with the expected values. By comparison, the current work’s ANN-ABC and ANN-PSO models outperform all previous studies with higher R² values (0.9913 and 0.9954) and lower RMSE scores (0.0457 and 0.0420), respectively, indicating improved predictive accuracy and generalization ability. The findings demonstrate that, in comparison to earlier models, the suggested models provide an exceptional prediction of the adsorbed gas amount in a heterogeneous porous medium. With additional data available, it may be easily updated for wider applications. Overall, this paper shows that machine learning can be used to forecast shale gas adsorption, and a well-trained model may be incorporated into a large numerical framework to optimize shale gas production curves. Full article

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27 pages, 3006 KiB

Open AccessArticle

Designing and Modeling Value-Added Production Sharing Contracts (VAPSC): From Offshore Gas to LNG in Lebanon

by Evgenii Marin, Tatiana Ponomarenko and Fatima Dirani

Resources 2025, 14(5), 79; https://doi.org/10.3390/resources14050079 - 16 May 2025

Viewed by 503

Abstract

This article presents the value-added production-sharing contract (VAPSC), an extension of traditional production-sharing contracts (PSCs), which encompasses raw materials production, subsequent processing, and the final ‘sharing’ of goods. Developing countries often face challenges in oil and gas exploration, production, and sector development, necessitating [...] Read more.

This article presents the value-added production-sharing contract (VAPSC), an extension of traditional production-sharing contracts (PSCs), which encompasses raw materials production, subsequent processing, and the final ‘sharing’ of goods. Developing countries often face challenges in oil and gas exploration, production, and sector development, necessitating new collaborative frameworks between governments, industries, and international companies. The study justifies the economic terms of VAPSC that align with Lebanon’s national regulations, focusing on offshore gas production and the subsequent production and sale of liquefied natural gas (LNG). The research evaluates VAPSC application in Lebanon through a case study involving offshore gas field development, LNG plant construction, and consequent LNG-sharing. Results demonstrate the VAPSC potential to promote petroleum sector development by generating added value for both the state and society, as well as economic efficiency for the contractor. The research contributes to contract theory by introducing VAPSC as a novel framework for integrating hydrocarbon extraction, subsequent processing, and value-added product distribution, offering a replicable model for other resource-rich developing nations. The main findings include the design of a new type of contract—VAPSC—along with an economic-mathematical model for optimizing government-investor partnerships and the definition of key contractual terms. Full article

(This article belongs to the Special Issue Production Efficiency and Environmental Research for Responsible Mining)

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19 pages, 2124 KiB

Open AccessArticle

Valorization of Andean Native Potatoes Through Chuño Processing: Effects of Potato Variety and Freezing Temperature on Physicochemical, Bioactive, Nutritional, and Technological Properties

by Elmer Robert Torres-Gutiérrez, Grimaldo Wilfredo Quispe-Santivañez, Jimmy Pablo Echevarría-Victorio, David Elí Salazar-Espinoza, Joselin Paucarchuco-Soto, Henry Juan Javier-Ninahuaman, Williams Esteward Castillo-Martinez and Rebeca Salvador-Reyes

Resources 2025, 14(5), 78; https://doi.org/10.3390/resources14050078 - 3 May 2025

Viewed by 464

Abstract

Chuño is a traditional Andean product obtained by freezing, thawing, and drying potatoes. This study aimed to assess how different Andean potato varieties (Chihuanki Negro [C], Puka Huayro Machu [P], and Yana Huayro Machu [Y]) and freezing temperatures (−10 °C, −20 °C, and [...] Read more.

Chuño is a traditional Andean product obtained by freezing, thawing, and drying potatoes. This study aimed to assess how different Andean potato varieties (Chihuanki Negro [C], Puka Huayro Machu [P], and Yana Huayro Machu [Y]) and freezing temperatures (−10 °C, −20 °C, and −30 °C) modulate the physicochemical (pH, acidity, and moisture), bioactive (phenolics and antioxidant activity), nutritional (proximate composition and minerals), and techno-functional (water absorption and swelling power) attributes of chuño. The results revealed that variety C retained higher macronutrient levels at 10 °C, featuring higher carbohydrates, proteins, and minerals (e.g., magnesium and zinc), while P showed enhanced fiber and mineral retention, alongside a faster rehydration and antioxidant capacity, particularly at −20 °C and −30 °C. Color differences were also noted, with P presenting reddish tones and a higher luminosity, whereas C had a more intense yellow hue linked to carotenoids. In general, −10 °C and −20 °C better preserved antioxidant compounds than −30 °C. These findings underscore how the proper selection of potato variety and freezing temperature can optimize the nutritional, functional, and sensory characteristics of chuño. However, these outcomes stem from selected samples, suggesting that further research is needed to confirm the broader applicability of the proposed method across additional varieties and process conditions. Full article

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23 pages, 4735 KiB

Open AccessArticle

Spatial Analysis of Water Conservation and Its Driving Factors in an Urban Citarum Tropical Watershed: Geospatial Approach

by Irmadi Nahib, Yudi Wahyudin, Wiwin Ambarwulan, Bono Pranoto, Fadhlullah Ramadhani, Destika Cahyana, Nunung Puji Nugroho, Nawa Suwedi, Jaka Suryanta, Vicca Karolinoerita, Mulyanto Darmawan, Aninda Wisaksanti Rudiastuti, Darmawan Listya Cahya, Bambang Winarno, Teguh Arif Pianto and Harun Idham Akbar

Resources 2025, 14(5), 77; https://doi.org/10.3390/resources14050077 - 3 May 2025

Viewed by 808

Abstract

Water conservation (WC) is a vital ecosystem service (ES) that plays an essential role in the sustainable management of water resources and ensures ecological security. This research examines the WC capacity of the Citarum watershed in West Java Province, Indonesia, from 2010 to [...] Read more.

Water conservation (WC) is a vital ecosystem service (ES) that plays an essential role in the sustainable management of water resources and ensures ecological security. This research examines the WC capacity of the Citarum watershed in West Java Province, Indonesia, from 2010 to 2020. The specific objectives of this research are as follows: (1) to assess the 10-year temporal and spatial variations of WC using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) and topographic index model; (2) to analyze the temporal interchange between WC and its influencing factors through the Spatial Elastic Coefficient Trajectory Model (SECTM); and (3) to determine the driving factors (DFs) affecting WC by applying Multiscale Geographically Weighted Regression (MGWR). Key findings of this study reveal significant trends in WC from 2010 to 2020: the average WC in the Citarum watershed decreased from 513.96 mm/ha to 453.64 mm/ha (11.74%), indicating a concerning decline in ES capacity. This study also noted that regions implementing comprehensive regulations dominated the study area, covering approximately 72.70% of the total area (502,295 hectares). This illustrates that the implementation of rules plays a crucial role in the WC. Lastly, the MGWR analysis found that WC in the Citarum watershed positively correlated with topography, climate, and vegetation while negatively correlating with socioeconomic factors. This indicates that WC levels are generally lower in areas with higher human activity and economic growth, highlighting the impact of anthropogenic pressures on natural resources. This framework helps stakeholders plan to ensure sustainable development in the area, as it provides valuable insights into the interactions between the ecological and socioeconomic factors affecting WC. Full article

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19 pages, 3538 KiB

Open AccessArticle

Aquafaba and Cinnamon Essential Oil for the Production of Biodegradable and Compostable Wine Vineyard Waste-Based Material

by Sergio Moraga-Bustos, Yessica Rivas, Ricardo Villalobos and Marcela Jarpa-Parra

Resources 2025, 14(5), 76; https://doi.org/10.3390/resources14050076 - 1 May 2025

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Abstract

(1) Grape stalks and aquafaba (Aq) from chickpeas are promising agricultural byproducts with potential applications in the development of sustainable biocomposite materials due to their ligno-cellulose and protein content. (2) This study aimed to evaluate the incorporation of Aq and cinnamon essential oil [...] Read more.

(1) Grape stalks and aquafaba (Aq) from chickpeas are promising agricultural byproducts with potential applications in the development of sustainable biocomposite materials due to their ligno-cellulose and protein content. (2) This study aimed to evaluate the incorporation of Aq and cinnamon essential oil (CEO) into grape stalk-based materials to enhance mechanical properties and prevent microbial contamination. Four formulations were prepared, and their mechanical, physicochemical, and antifungal properties were assessed. (3) The incorporation of CEO significantly reduced water absorption, while formulations containing Aq exhibited the highest mechanical resistance, likely due to synergistic interactions between proteins and polysaccharides that modified the microstructure of cellulose fibers. Scanning electron microscopy (SEM) images supported these findings. Additionally, CEO-treated samples showed resistance to fungal contamination by Botrytis cinerea, unlike untreated samples, which were colonized by the fungus. Biodegradability tests indicated slower degradation for CEO-treated samples (10 weeks) compared to those without CEO (5–7 weeks). (4) The results suggest that the combination of Aq and CEO creates a promising material for use in food packaging, though further research is needed to fully understand the reinforcement mechanisms. Full article

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20 pages, 5188 KiB

Open AccessArticle

Investigation of Bio-Oil and Biochar Derived from Cotton Stalk Pyrolysis: Effect of Different Reaction Conditions

by Hussien Elshareef, Obid Tursunov, Sihao Ren, Katarzyna Śpiewak, Alina Rahayu Mohamed, Yongkun Fu, Renjie Dong and Yuguang Zhou

Resources 2025, 14(5), 75; https://doi.org/10.3390/resources14050075 - 28 Apr 2025

Viewed by 336

Abstract

This work aimed to conduct a kinetic study of cotton stalks (CSs) through TGA to examine the impact of reaction conditions on bio-oil yield derived from CS slow pyrolysis using a tube furnace lab-scale reactor, as well as a characterization of bio-oil and [...] Read more.

This work aimed to conduct a kinetic study of cotton stalks (CSs) through TGA to examine the impact of reaction conditions on bio-oil yield derived from CS slow pyrolysis using a tube furnace lab-scale reactor, as well as a characterization of bio-oil and biochar products. The iso-conversional approaches of Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO) were applied to estimate kinetic parameter activation energy (E_a) for the range of conversion degrees (α = 0.1–0.9). The kinetic results demonstrated that the average values of E_a for secondary pyrolysis were lower compared to those of primary pyrolysis; this could be explained by the fact that mainly cellulose degrades during primary pyrolysis, which requires more energy to be degraded. The pyrolysis findings indicated that the highest yield of bio-oil was 38.5%, which occurred at conditions of 500 °C and 0.5–1 mm size, while retention time showed an insignificant effect on pyrolysis oil. GC–MS analysis demonstrated that bio-oil is dominated by phenol compounds, which account for more than 40% of its components. SEM and XRD analyses emphasized that biochar is porous and has an amorphous shape, respectively. It can be concluded that these outcomes confirm that CSs have the potential to be a good candidate for a feedstock material for bioenergy production via the pyrolysis process. Full article

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28 pages, 2733 KiB

Open AccessArticle

Techno-Economic Optimization and Assessment of Solar Photovoltaic–Battery–Hydrogen Energy Systems with Solar Tracking for Powering ICT Facility

by Olubayo Babatunde, Oluwaseye Adedoja, Oluwaseun Oyebode, Uthman Abiola Kareem, Damilola Babatunde, Toyosi Adedoja, Busola Akintayo, Michael Emezirinwune, Desmond Eseoghene Ighravwe, Olufemi Ogunniran and Olanrewaju Oludolapo

Resources 2025, 14(5), 74; https://doi.org/10.3390/resources14050074 - 28 Apr 2025

Viewed by 342

Abstract

This paper addresses the critical issue of selecting the optimal solar tracking configuration for maximum energy generation, given the increasing demand for sustainable energy solutions in information and communication technology (ICT) facilities. The main goal is to thoroughly evaluate and compare seven different [...] Read more.

This paper addresses the critical issue of selecting the optimal solar tracking configuration for maximum energy generation, given the increasing demand for sustainable energy solutions in information and communication technology (ICT) facilities. The main goal is to thoroughly evaluate and compare seven different solar tracking configurations across technical, economic, and environmental dimensions: No Tracking (NT), Monthly Adjusted Horizontal Axis (MAHA), Weekly Adjusted Horizontal Axis (WAHA), Daily Adjusted Horizontal Axis (DAHA), Continuously Adjusted Horizontal Axis (CAHA), Continuously Adjusted Vertical Axis (CAVA), and Dual Axis with Continuous Adjustment (DACA). This study utilizes the HOMER simulation program to evaluate its energy and hydrogen production, emissions, and cost-effectiveness performance. Key findings indicate solar tracking improves energy efficiency, with optimal capacity factors of 18.2% and 17.7% for CAHA and DAHA configurations, respectively. Although load-following strategies increase reliability, there is a trade-off between capital costs and energy costs. In addition, an MCDM approach helps to consolidate the evaluation, resulting in CAVA being ranked as the most preferable option. The study contributes to informed decision-making for energy systems in ICT facilities by emphasizing the significance of considering a variety of criteria and evaluation techniques to address complex energy challenges. Full article

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17 pages, 4046 KiB

Open AccessArticle

Effects of Ettringite Formation on the Stability of Cement-Treated Sediments

by Inácio Soares Ribeiro, Diego de Freitas Fagundes and Helena Paula Nierwinski

Resources 2025, 14(5), 73; https://doi.org/10.3390/resources14050073 - 28 Apr 2025

Viewed by 379

Abstract

This study explores the stabilization of dredged sediments classified as lean clay (CL) using hydrated lime, type III Portland cement, and compaction. While quicklime is commonly used in practice, this research explores alternative calcium-based binders with the aim of valorizing sediments for civil [...] Read more.

This study explores the stabilization of dredged sediments classified as lean clay (CL) using hydrated lime, type III Portland cement, and compaction. While quicklime is commonly used in practice, this research explores alternative calcium-based binders with the aim of valorizing sediments for civil engineering applications. The mechanical behavior of the treated materials was evaluated through an Unconfined Compressive Strength (UCS) test campaign, with the results interpreted using the porosity/volumetric cement content (

η / C_{i v}

) index. This relationship assesses the influence of apparent dry density and cement content on the strength improvement of sediments, aiming to evaluate the suitability of the dredged sediments for engineering applications. A key feature of this study is the extended curing period of up to 90 days, which goes beyond the typical 28-day evaluations commonly found in the literature. Interestingly, strength degradation occurred at advanced curing ages compared to shorter curing times. To understand the mechanisms underlying this resistance degradation, the mixtures were subjected to X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). These tests identified the presence of the expansive sulfate-based compound ettringite, which is associated with swelling and failure in soils stabilized with calcium-based stabilizers. This research contributes to the field by demonstrating the limitations of calcium-based binders in stabilizing sulfate-bearing dredged materials and emphasizing the importance of long-term curing in assessing the durability of treated sediments. Full article

(This article belongs to the Topic Sustainable Recycling and Reuse of Industrial By-Products or Waste from Geo-Resource Exploitation)

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19 pages, 935 KiB

Open AccessArticle

Enhancing the Growth, Bioactive Compounds, and Antioxidant Activity of Kangkong (Ipomoea aquatica Forssk.) Microgreens Using Dielectric Barrier Discharge Plasma

by Prapasiri Ongrak, Nopporn Poolyarat, Suebsak Suksaengpanomrung, Bhornchai Harakotr, Yaowapha Jirakiattikul and Panumart Rithichai

Resources 2025, 14(5), 72; https://doi.org/10.3390/resources14050072 - 28 Apr 2025

Viewed by 446

Abstract

Enhancing the nutraceutical value of health-promoting foods is a strategy to mitigate non-communicable diseases (NCDs), which pose a global health threat. This study aimed to improve the growth, bioactive compound content, and antioxidant activity of kangkong (Ipomoea aquatica Forssk.) microgreens through the [...] Read more.

Enhancing the nutraceutical value of health-promoting foods is a strategy to mitigate non-communicable diseases (NCDs), which pose a global health threat. This study aimed to improve the growth, bioactive compound content, and antioxidant activity of kangkong (Ipomoea aquatica Forssk.) microgreens through the application of dielectric barrier discharge (DBD) plasma at different treatment durations. Seeds from two cultivars, Pugun 19 (PG) and Banhann (BH), were treated with DBD plasma for 5 to 20 min, compared to untreated seeds as the control. DBD plasma treatments had no significant effect on the dry weight of BH, whereas a 10 min treatment resulted in the highest dry weight in PG. Principal component analysis exhibited that treating PG seeds with 5 min of DBD plasma increased coumaric acid, total flavonoids, and DPPH and FRAP activities. Meanwhile, exposing BH seeds to 10 min DBD plasma treatment enhanced carotenoids content, as well as ABTS and antiglycation activities. Based on these results, the optimal time for DBD plasma treatment to improve the quality of kangkong microgreens was 5 min for PG and 10 min for BH. These findings indicate that DBD plasma treatment offers potential applications in sustainable agriculture and food biofortification. Full article

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18 pages, 2373 KiB

Open AccessArticle

Yield, Bioactive Compounds, and Antioxidant Potential of Twenty-Three Diverse Microgreen Species Grown Under Controlled Conditions

by Bhornchai Harakotr, Lalita Charoensup, Panumart Rithichai, Yaowapha Jirakiattikul and Patlada Suthamwong

Resources 2025, 14(5), 71; https://doi.org/10.3390/resources14050071 - 27 Apr 2025

Viewed by 428

Abstract

Selecting suitable crop species is crucial for optimizing the productivity and nutritional content of microgreens. In this study, twenty-three diverse microgreen species, grown under controlled conditions, were analyzed for yield, bioactive compounds, and antioxidant activities. The microgreens were cultivated on a peat substrate [...] Read more.

Selecting suitable crop species is crucial for optimizing the productivity and nutritional content of microgreens. In this study, twenty-three diverse microgreen species, grown under controlled conditions, were analyzed for yield, bioactive compounds, and antioxidant activities. The microgreens were cultivated on a peat substrate in a controlled environment, with a growth period of 6 to 20 days from planting to harvest. Conditions were maintained at 25 ± 2 °C, a 16 h photoperiod, CO₂ concentration of 1000 ppm, relative humidity of 60 ± 2%, and the LED light was set at 330 μmol/m²/s PPFD. Results from the analysis revealed that the yield, bioactive compounds, and antioxidant potential differed significantly among the twenty-three microgreen species. Unfortunately, the superior microgreens exhibiting greater values for all studied traits could not be identified. However, the principal component analysis (PCA) clustered red radish, rat-tailed radish, and Chinese kale microgreens, which were high in both yield and bioactive compounds. In contrast, red holy basil and lemon basil microgreens had high levels of these compounds but low yields. Additionally, a high level of anti-tyrosinase activity was observed in garland chrysanthemum, Chinese mustard, and Chinese cabbage microgreens. Therefore, these microgreen species can be utilized individually or in varying ratios to produce bioactive compounds in different concentrations that are suitable for various applications. The information presented in this study provides valuable insights for health-conscious consumers and growers for selecting superior species with functional implications. Full article

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21 pages, 4109 KiB

Open AccessArticle

Using Coal Resources with Optimal Bursting Pressure for the Production of High-Quality Metallurgical Coke

by Denis Miroshnichenko, Kateryna Shmeltser, Maryna Kormer, Oleksiy Sytnyk, Iliya Avdeyuk, Mykhailo Miroshnychenko and Mariia Shved

Resources 2025, 14(5), 70; https://doi.org/10.3390/resources14050070 - 23 Apr 2025

Viewed by 287

Abstract

When applying advanced technologies and technological methods for the preparation of coal raw materials (technology for coking stamped batch, technology for coking dry or thermally prepared batch), the problem of developing high bursting pressure arises. The aim of this research is to assess [...] Read more.

When applying advanced technologies and technological methods for the preparation of coal raw materials (technology for coking stamped batch, technology for coking dry or thermally prepared batch), the problem of developing high bursting pressure arises. The aim of this research is to assess the possibility of predicting the bursting pressure of coal blends taking into account their technological properties and petrographic characteristics, as well as to study the effect of bursting pressure on the metallurgical properties of coke. Standardized methods were used to study the technological properties of coal and coal blends (determination of technical and petrographic analyses). The qualitative characteristics of coke were studied using physical, mechanical, and thermochemical methods for the study of standardized indicators: crushability (M₂₅), abrasion (M₁₀), reactivity (CRI), and post-reaction strength (CSR). The regression equations for predicting the bursting pressure of coal blends, taking into account the volatile matter in the blend, vitrinite content, and grinding, which are characterized by high correlation coefficients (0.89 and 0.9), were proposed. Their use will make it possible to optimize the composition of coal batches, control the bursting pressure during regrinding, and reduce the number of experimental measurements in a particular coke production. It was also found that an increase in the bursting pressure by 1 kPa can be expected to increase the mechanical strength of coke in terms of crushability M₂₅ by about 2.6% and reduce the abrasion of coke M₁₀ by 1%. Full article

(This article belongs to the Special Issue Mineral Resource Management 2025: Assessment, Mining and Processing)

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23 pages, 875 KiB

Open AccessArticle

Microbial and Physiochemical Profiling of Zarqa River Supplemented with Treated Wastewater: A High-Resolution PCR Analysis

by Raha Alassaf and Alfred P. Blaschke

Resources 2025, 14(5), 69; https://doi.org/10.3390/resources14050069 - 22 Apr 2025

Viewed by 360

Abstract

Background: This study aims to evaluate the quality of treated wastewater flowing in the Zarqa River to determine its suitability for agricultural use. The assessment is based on physicochemical and biological parameters in accordance with Jordanian standards (JS 893:2021), the CCME water quality [...] Read more.

Background: This study aims to evaluate the quality of treated wastewater flowing in the Zarqa River to determine its suitability for agricultural use. The assessment is based on physicochemical and biological parameters in accordance with Jordanian standards (JS 893:2021), the CCME water quality index, and the weighted arithmetic water quality index (WAWQI). Additionally, a microbial assessment was conducted to identify the presence of pathogens in the treated wastewater. Methods: A total of 168 water samples were collected from seven different sites along the Zarqa River over a 24-month period. This study focused on microbial assessment and selected parameters from the JS 893:2021, including total dissolved solids (TDSs), biochemical oxygen demand (BOD), dissolved oxygen (DO), chemical oxygen demand (COD), and E. coli levels. Furthermore, data were gathered on additional physicochemical parameters such as pH, mineral content (including Na, Ca, K, Mg, and Cl), salts (HCO₃, SO₄, NO₃, and PO₄), and heavy metals (Fe, Cu, Pb, Mn, and Co). The CCME water quality index and weighted arithmetic WQI scores were calculated to determine the water quality from all seven study sites. Results: In terms of Jordanian standards, Site 1 had the lowest TDS and DO values along with E. coli concentration. Further, in terms of minerals and salts, the maximum concentrations found for the sites are given herewith: Site 2 (K⁺ and NO₃), Site 3 (Cl⁻, Na⁺), Site 5 (Ca, HCO₃), and Site 7 (Mg²⁺, PO₄, and SO₄). In terms of pH, all the study sites had pH values within the acceptable range, i.e., between 6 and 9, for irrigation purposes. The concentrations of certain heavy metals, specifically lead (Pb), manganese (Mn), and cobalt (Co), were observed to be negligible. In contrast, Site 6 exhibited the highest concentration of iron (Fe) (0.0178 mg/L), while Site 5 recorded the maximum concentration of copper (Cu) (0.0210 mg/L) among the study locations. Site 1 demonstrated the most favorable water quality among the seven sites evaluated, whereas Site 6 exhibited the poorest water quality. Overall, the water quality from the majority of the sites was deemed suitable for drainage and for irrigating crops classified under the B category. However, based on the weighted arithmetic water quality index (WQI) values, none of the sites achieved a classification of good or excellent water quality, although the water quality at these sites may still be utilized for irrigation purposes. The current study is the first to report the presence of SARS-CoV-2 in Zarqa River water samples. Conclusions: The current study outcomes are promising and provide knowledgeable insights in terms of water quality parameters, while public health aspects should be considered when planning the WWTPs in parallel to reclaiming the wastewater for irrigation purposes. Full article

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24 pages, 2988 KiB

Open AccessArticle

The Role of Positive Energy Communities in Accelerating the Adoption of Renewable Energies: Case Study, Tunisia

by Ikram Ben Belgacem, El Manaa Barhoumi, Issam M. Bahadur and Paul C. Okonkwo

Resources 2025, 14(5), 68; https://doi.org/10.3390/resources14050068 - 22 Apr 2025

Viewed by 385

Abstract

This paper examines the key factors influencing the relationship between domestic energy consumption and renewable energy adoption in Tunisia, based on a survey of 1000 participants from various sectors, including students, teachers, and social media users. The findings reveal that while 65% of [...] Read more.

This paper examines the key factors influencing the relationship between domestic energy consumption and renewable energy adoption in Tunisia, based on a survey of 1000 participants from various sectors, including students, teachers, and social media users. The findings reveal that while 65% of households report high energy consumption, mainly due to heating and air conditioning, only 35% have adopted energy-efficient technologies. Although 80% express concern about climate change, only 45% understand the connection between personal energy use and environmental impact. Additionally, 70% of respondents show a positive attitude toward solar energy, but 60% cite installation costs as a significant barrier. The paper focuses on the potential of positive energy communities (PECs), particularly in rural areas, where 75% of respondents showed interest. The study emphasizes the need for a comprehensive strategy combining education, policy frameworks, and community-driven energy solutions to reduce consumption and increase renewable energy use. Concrete recommendations are provided to support a sustainable energy transition in Tunisia, with a focus on enhancing energy autonomy and environmental preservation through PECs. Full article

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Resources, Volume 14, Issue 5 (May 2025) – 17 articles

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