Search Results (868)

In the context of urban decarbonization, multi-energy microgrids (MEMGs) are gaining increasing relevance due to their ability to enhance synergies across multiple energy vectors. This study presents a block-based MILP framework developed to optimize the operations of a real MEMG, with a particular focus on accurately modeling the structure of electricity and natural gas bills. The objective is to assess the added economic value of integrating a battery energy storage system (BESS) under the assumption it is employed to provide implicit flexibility—namely, bill management, energy arbitrage, and peak shaving. Results show that under assumed market conditions, tariff schemes, and BESS costs, none of the analyzed BESS configurations achieve a positive net present value. However, a 2 MW/4 MWh BESS yields a 3.8% reduction in annual operating costs compared to the base case without storage, driven by increased self-consumption (+2.8%), reduced thermal energy waste (–6.4%), and a substantial decrease in power-based electricity charges (–77.9%). The performed sensitivity analyses indicate that even with a significantly higher day-ahead market price spread, the BESS is not sufficiently incentivized to perform pure energy arbitrage and that the effectiveness of a time-of-use power-based tariff depends not only on the level of price differentiation but also on the BESS size. Overall, this study provides insights into the role of BESS in MEMGs and highlights the need for electricity bill designs that better reward the provision of implicit flexibility by storage systems. Full article

The transition towards a power system characterized by a reduced presence of synchronous generators (SGs) and an increased reliance on inverter-based resources (IBRs), including wind, solar photovoltaics (PV), and battery storage, presents new operational challenges, particularly when these sources exceed 50–60% of the system’s demand. While current grid-following (GFL) IBRs, which are equipped with fast and rigid control systems, continue to dominate the inverter landscape, there has been a notable surge in research focused on grid-forming (GFM) inverters in recent years. This study conducts a comparative analysis of the practicality and control methodologies of GFM inverters relative to traditional GFL inverters from a system planning perspective. A comprehensive framework aimed at assisting system developers and consulting engineers in the grid-integration of wide-scale renewable energy sources (RESs), incorporating strategies for the deployment of inverters, capacitor banks, and harmonic filters, is proposed in this paper. The discussion includes an examination of the reactive power capabilities of the plant’s inverters and the provision of additional reactive power to ensure compliance with grid interconnection standards. Furthermore, the paper outlines a practical approach to assess the necessity for enhanced filtering measures to mitigate potential resonant conditions and achieve harmonic compliance at the installation site. The objective of this work is to offer useful guidelines and insights for the effective addition of RES into contemporary power systems. Full article

Tiny Machine Learning (TinyML) extends edge AI capabilities to resource-constrained devices, offering a promising solution for real-time, low-power intelligence in smart cities. This review systematically analyzes 66 peer-reviewed studies from 2019 to 2024, covering applications across urban mobility, environmental monitoring, public safety, waste management, and infrastructure health. We examine hardware platforms and machine learning models, with particular attention to power-efficient deployment and data privacy. We review the approaches employed in published studies for deploying machine learning models on resource-constrained hardware, emphasizing the most commonly used communication technologies—while noting the limited uptake of low-power options such as Low Power Wide Area Networks (LPWANs). We also discuss hardware–software co-design strategies that enable sustainable operation. Furthermore, we evaluate the alignment of these deployments with the United Nations Sustainable Development Goals (SDGs), highlighting both their contributions and existing gaps in current practices. This review identifies recurring technical patterns, methodological challenges, and underexplored opportunities, particularly in the areas of hardware provisioning, usage of inherent privacy benefits in relevant applications, communication technologies, and dataset practices, offering a roadmap for future TinyML research and deployment in smart urban systems. Among the 66 studies examined, 29 focused on mobility and transportation, 17 on public safety, 10 on environmental sensing, 6 on waste management, and 4 on infrastructure monitoring. TinyML was deployed on constrained microcontrollers in 32 studies, while 36 used optimized models for resource-limited environments. Energy harvesting, primarily solar, was featured in 6 studies, and low-power communication networks were used in 5. Public datasets were used in 27 studies, custom datasets in 24, and the remainder relied on hybrid or simulated data. Only one study explicitly referenced SDGs, and 13 studies considered privacy in their system design. Full article

Steam networks are widely used for industrial heat supply. High-temperature heat pumps (HTHPs) are an increasingly attractive low-emission solution to traditional steam generation, which could also improve the operational efficiency and energy demand flexibility of industrial processes. This work characterises 4-bar steam supply via HTHPs and aims to assess how variations in power input that result from flexible HTHP operation may affect steam flow and temperature, both with and without a downstream steam accumulator (SA). First, steady-state modelling is used for system design. Then, dynamic component models are developed and used to simulate the system response to HTHP power input variations. The performance of different SA integration layouts and sizes is evaluated. Results demonstrate that steam supply fluctuations closely follow changes in HTHP operation. A downstream SA is shown to mitigate these variations to an extent that depends on its capacity. Practical SA sizing recommendations are derived, which allow for the containment of steam supply fluctuations within acceptability. By providing a basis for evaluating the financial viability of flexible HTHP operation for steam provision, the results support clean technology’s development and uptake in industrial steam and district heating networks. Full article

Lipid metabolism is critical for the physiological activities of signal transduction, metabolic regulation, and energy provision, and Wuzhishan (WZS) pigs are a promising animal model for studying human diseases. However, lipid metabolites in the heart and liver of WZS pigs are indistinct. In this study, we detected gene expression, blood biochemical parameters, and metabolic profiles of hearts and livers of WZS and Large White (LW) pigs, and analyzed correlations between metabolites. The results showed that the fatty acid metabolic process was present in both the heart and liver, and was more dominant in the liver. Although the expression of lipid absorption-related genes of CYP7A1 increased in the liver, CEBPB levels increased in both the liver and heart; the fatty acid beta-oxidation genes RXRA and ACSS2 also showed increased expression. The quantity of metabolites related to lipid synthesis decreased in the liver, heart, and blood for WZS pigs compared to that of LW pigs, indicating a balance of lipid synthesis and breakdown for WZS pigs. Moreover, the lipid metabolites in the liver and heart exhibited strong correlations with each other and showed similar correlations to blood biochemical parameters, respectively. This study declared the balance of lipid metabolism in both the heart and liver, and identified their connections for WZS pigs. Full article

With the increasing penetration of renewables, the importance of electrical energy storage (EES) for power supply stabilization is growing. The intermittency of renewable energy sources remains the main issue limiting their rapid integration; however, the development of high-capacity batteries capable of storing large quantities of energy offers a way to address this challenge. This article presents and describes dedicated algorithms for controlling the EES system to enable the provision of individual system services. Five services are planned for implementation: RES power stabilization; voltage regulation using active and reactive power; reactive power compensation; power stabilization of unstable loads; and power reduction on demand. The aim of this paper is to develop new, dedicated energy storage control algorithms for delivering these specific services. Additionally, the voltage regulation algorithm includes two operating modes: short-term regulation (voltage fluctuation stabilization) and long-term regulation (triggered by an operator signal). Full article

The poll gland, a specialized tissue of male Bactrian camels, undergoes seasonal enlargement and marked metabolic activation during the rutting season. However, the metabolic mechanisms of the poll gland and its role in rutting activities and inducing estrus are still not fully understood. This study aimed to investigate the contribution of fatty acid metabolic pathways, specifically those mediated by carnitine palmitoyltransferase 1A (CPT1A), in poll gland activity during the breeding season; poll gland tissue, neck mane, and urine samples were systematically collected from healthy male Bactrian camels stratified into breeding and non-breeding season groups for integrated proteomic, metabolomic, and biochemical assays. Histological and immunohistochemical analyses revealed reduced adipocytes but elevated ATP production in rutting camels, suggesting increased mitochondrial activity and enhanced oxidative phosphorylation. Proteomic analyses identified 119 differentially expressed proteins (DEPs) linked to fatty acid metabolism, with CPT1A, a key regulator of mitochondrial fatty acid oxidation, emerging as a central hub. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis further confirmed enrichment in fatty acid biosynthesis, degradation, and PPAR/AMPK signaling. The metabolomic analysis identified 14 metabolites, including acetylcarnitine and glycine, that were closely correlated with CPT1A expression, suggesting their potential involvement in regulating fatty acid metabolism during the breeding season. Quantitative expression analyses revealed that CPT1A in glandular acini was significantly upregulated in the breeding group compared to the non-breeding group across all assays: qPCR (2.53-fold, p < 0.05), Western blot (3.5-fold, p < 0.05), and immunohistochemistry (1.5-fold, p < 0.05). This demonstrated that CPT1A-mediated fatty acid metabolism plays a pivotal role in energy provision for reproductive activities. The results suggested that CPT1A-mediated fatty acid oxidation sustains poll gland function and reproductive behaviors in male Bactrian camels. This study provided a theoretical basis for understanding the role of CPT1A-mediated fatty acid oxidation in maintaining poll gland function and supporting reproductive activities in male Bactrian camels. Full article

This study analyzed the frequency control challenges within the West Africa Power Pool Interconnected Transmission System (WAPPITS) as it plans to incorporate variable renewable energy (VRE) resources, such as wind and solar energy. Concerns center on the ability of WAPPITS primary frequency control reserves to adapt to high VRE penetration given the synchronization and frequency control problems experienced by the three separate synchronous blocks of WAPPITS. Optimizing solutions requires a better understanding of WAPPITS’ current frequency control approach. This study used questionnaires to understand operators’ practical experience with frequency control and compared these observations to field tests at power plants and frequency response metrics during system events. Eight (8) of ten (10) Transmission System Operators (TSOs) indicated that primary frequency control service was implemented in the TSO, but nine (9) of ten TSOs indicated that the reserves provided were inadequate to meet system needs. Five (5) of ten (10) respondents answered “yes” to the provision of secondary frequency control service, while only one (1) indicated that secondary reserves were adequate. Three (3) TSOs indicated they have AGC (Automatic Generation Control) installed in the control room, but none have implemented it for secondary frequency control. The results indicate a significant deficiency in primary control reserves, resulting in a reliance on under-frequency load shedding for primary frequency control. Additionally, the absence of an AGC system for secondary frequency regulation required manual intervention to restore frequency after events. To ensure the effectiveness of battery energy storage systems (BESSs) and the reliable operation of the WAPPITS with a higher penetration of inverter-based VRE, this paper recommends (a) implementing and enforcing basic primary frequency control structures through regional regulation and (b) establishing an ancillary services market to mobilize secondary frequency control resources. Full article

Fermented apple juice (FAJ), a nutrient-dense beverage rich in vitamins, offers multiple health benefits, including improved digestion, enhanced fat metabolism, and sustained energy provision with reduced caloric intake. To advance the development of probiotic-enriched flavored and functional juices, this study establishes Lactiplantibacillus plantarum (L. plantarum) as a safe and effective starter culture for apple juice fermentation. The selected strain exhibited minimal biogenic amine synthesis, producing only 30.55 ± 1.2 mg/L of putrescine and 0.59 ± 0.55 mg/L of cadaverine, while histamine and tyramine were undetectable. Furthermore, the strain demonstrated no hemolytic activity and exhibited robust biofilm-forming capacity, reinforcing its suitability for fermentation applications. An electronic nose analysis revealed that L. plantarum significantly enriched the volatile compound profile of FAJ, leading to an improved flavor profile. The strain also displayed excellent growth adaptability in the apple juice matrix, further optimizing fermentation efficiency and sensory quality. Crucially, 16S rRNA sequencing demonstrated that FAJ specifically restructures the gut microbiota in obese individuals, significantly elevating the relative abundance of beneficial genera, including Enterococcus, Parabacteroides, and Bifidobacterium (p < 0.05). Concurrently, FAJ enhanced glycolytic activity, suggesting a potential role in metabolic regulation. Collectively, these findings confirm that L. plantarum-fermented FAJ combines favorable sensory properties and safety with promising anti-obesity effects mediated through gut microbiome modulation and metabolic pathway activation. This study provides a critical scientific foundation for designing next-generation functional fermented beverages with targeted health benefits. Full article

Donkey milk has received increasing attention in recent years due to its unique nutritional composition and potential biological activities. This comprehensive review analyzed the main nutritional components of donkey milk, including proteins, lipids, carbohydrates, vitamins, and minerals, while also examining its significant biological activities such as antioxidant, antimicrobial, immunomodulatory, and anti-inflammatory properties. The protein profile of donkey milk is notable for its high proportion of whey proteins (55–65%), resembling human milk more closely than cow milk. Its relatively low-fat content (approximately 1.29%) with higher proportions of unsaturated fatty acids provides nutritional advantages for specific dietary needs. The carbohydrate content, primarily lactose, contributes to energy provision and calcium absorption. Donkey milk is also distinguished by its rich vitamin profile, particularly vitamin C (about 4.75 times higher than cow milk), and essential minerals including calcium, phosphorus, and zinc. The biological activities of donkey milk extend to various applications in infant nutrition, particularly for children with cow milk protein allergies, potential medical treatments for infections and inflammatory conditions, and cosmetic formulations. Despite these promising attributes, the donkey milk industry faces challenges including low milk yield, lack of standardized production methods, and quality control measures. The sustainable development of the donkey milk industry requires comprehensive approaches to resource protection, technological innovation, brand building, and supportive policies to realize its full potential in contributing to human health and economic development. Full article

This research introduces an energy prediction framework at the facility level supported by automated data collection and machine learning models. It investigates whether reducing the prediction time scale allows for applying more complex machine learning techniques and if those techniques improve the prediction accuracy. The primary advantages of this framework lie in its automation of the energy prediction process and its provision of real-time energy data suitable for use in energy dashboards or digital twins. A sitewide dataset was created by combining 15 min energy and daily production data of five shops—assembly, battery, body (electric), body (gas), and paint—from a globally recognized electric vehicle manufacturer. Various machine learning models were evaluated on daily, weekly, and monthly datasets, including, in increasingly complex order: naïve, simple linear regression, net regularized generalized linear regression, principal component regression, k-nearest neighbor, random forest, and Bayesian regularized neural network. Compared to the current state-of-the-art energy consumption prediction for the industrial facility level, this research investigates more complex models and smaller time intervals for higher accuracy. The findings revealed that the more complex monthly models require a minimum of a year and a half of data to operate, while weekly models demand a year of data to achieve improved accuracy. Daily models can operate with only six months of data but exhibit poor performance due to reduced prediction accuracy of production. Key challenges identified include access to reliable, high-quality energy and production data and the initial demand for human labor. Full article

Background: There is limited knowledge about nutritional intake and energy needs during the post-intensive care unit (ICU) period and their relationship with clinical outcomes and physical recovery. Aims and Methods: Thus, this observational multicenter study (Azienda Ospedaliero-Universitaria “Santa Maria”, Terni and “Madonna del Soccorso” General hospital, San Benedetto del Tronto, Italy) aimed, firstly, to measure energy expenditure via indirect calorimetry (IC) (Q-NRG+^® Metabolic Monitor, Cosmed, Rome, Italy), derived respiratory quotient (R/Q1) and, malnutrition risk via Mini Nutritional Assessment (MNA) test and body composition through bioimpedance vector analysis (BIVA-Akern, Pontassieve, Italy); secondly, to assess their effect on energy needs, body composition and physical rehabilitation steps in critically ill adults after ICU discharge. The provision of nutrients (PIS test) was also recorded. Oral nutritional supplementation was used to reach the optimal nutritional intake. All patients followed a standardized rehabilitation program. Results: A total of 43 patients were enrolled from January 2024 until February 2025 at the beginning of their post-ICU period. The mean age was 65.7 ± 1.0 years, the mean BMI was 20.73 ± 0.8 kg/m² at the recovery ward, and 60.4% (n = 26) were male. The mean admission period was 19.5 ± 1.7 days. The resting energy expenditure (mREE) was 1591 ± 71.2 at the admission and 1.856 ± 62.7 kcal/kg/d at the discharge (p < 0.05). The median phase angle value was 4.33 ± 0.15 at the admission and 5.05 ± 0.17° at the discharge (p < 0.05); R/Q1 at the admission was 0.7 ± 0.1 and 1.086± 0.11 at the discharge (p < 0.05). Improved energy expenditure significantly correlated with R/Q1 and phase angle (r = 0.81 and r = 0.72, respectively). Interestingly, there was no significant correlation between improved metabolism and improved PIS test scores (r = 0.18). Improved metabolism and nutritional status showed a tendency to correlate with shorter post-ICU courses and earlier physical recovery, without reaching statistical significance. Conclusions: Measurement of energy expenditure and caloric intake, along with the assessment of body composition is feasible and provides an objective tool to guide and possibly enhance the functional recovery in patients during the post-ICU period. Full article

The provision of food in pre-Inca/Inca cultures (1000 BC–≈1532 AD) in environments near Lake Titikaka (approximately 4000 m above sea level) was possible through an agricultural technique called “Waru-Waru”, which consists of filling the space (volume) between rows of land containing plants that are cultivated (a series of earth platforms surrounded by water canals) with water, using water as thermal energy storage to store energy during the day and to regulate the temperature of the soil and crop atmosphere at night. The problem is that these cultures left no evidence in written documents that have been preserved to this day indicating the mathematical models, the physics involved, and the experimental part they performed for the research, development, and innovation of the “Waru-Waru” technique. From a review of the existing literature, there is (1) bibliography that is devoted to descriptive research (about the geometry, dimensions, and shapes of the crop fields (and more based on archaeological remains that have survived to the present day) and (2) studies presenting complex mathematical models with many physical parameters measured only with recently developed instrumentation. The research objectives of this paper are as follows: (1) develop a mathematical model that uses finite differences in fluid mechanics, thermodynamics, and heat transfer to explain the experimental and theory principles of this pre-Inca/Inca technique; (2) the proposed mathematical model must be in accordance with the mathematical calculation tools available in pre-Inca/Inca cultures (yupana and quipu), which are mainly based on arithmetic operations such as addition, subtraction, and multiplication; (3) develop a mathematical model in a sequence of steps aimed at determining the best geometric form for thermal energy storage and plant cultivation and that has a simple design (easy to transmit between farmers); (4) consider the assumptions necessary for the development of the mathematical model from the point of view of research on the geometry of earth platforms and water channels and their implantation in each cultivation area; (5) transmit knowledge of the construction and maintenance of “Waru-Waru” agricultural technology to farmers who have cultivated these fields since pre-Hispanic times. The main conclusion is that, in the mathematical model developed, algebraic mathematical expressions based on addition and multiplication are obtained to predict and explain the evolution of soil and water temperatures in a specific crop field using crop field characterization parameters for which their values are experimentally determined in the crop area where a “Waru-Waru” is to be built. Therefore, the storage of thermal energy in water allows crops to survive nights with low temperatures, and indirectly, it allows the interpretation that the Inca culture possessed knowledge of mathematics (addition, subtraction, multiplication, finite differences, approximation methods, and the like), physics (fluids, thermodynamics, and heat transfer), and experimentation, with priority given to agricultural techniques (and in general, as observed in all archaeological evidence) that are in-depth, exact, practical, lasting, and easy to transmit. Understanding this sustainable energy storage technique can be useful in the current circumstances of global warming and climate change within the same growing areas and/or in similar climatic and environmental scenarios. This technique can help in reducing the use of fossil or traditional fuels and infrastructure (greenhouses) that generate heat, expanding the agricultural frontier. Full article

Poland is a country with significant lignite resources. Prospecting for and exploring lignite deposits, as well as lignite extraction, requires prior acquisition of an appropriate concession. As concessions serve as instruments for regulating economic activity—and thereby constitute a form of permissible restriction on such activity under the Polish Constitution—the legal provisions governing them must be enacted by statute. This article analyzes the role of state policies relating to lignite extraction and its use in electricity generation, and examines the concession procedure as a regulatory instrument, with a particular focus on one specific ground for refusing to grant a concession: inconsistency with the state’s raw material interest. The main research question addresses whether the incorporation of the state’s raw material interest as grounds for refusal complies with constitutional standards and whether policy documents—specifically the State Raw Materials Policy and the State Energy Policy—can effectively guide its interpretation. The analysis concludes that, while the constitutional framework permits such a ground for refusal, current policy documents require updates and greater specificity to ensure legal certainty and consistency in administrative practices. Full article

The process of conceptualisation and prototyping of electric energy products is demanding due to the need for a multifaceted approach to product design. This task becomes even more complex during sustainable development, within which supporting techniques are sought. Energy conversion products such as electric motorcycles require special attention due to their impact on energy efficiency, environmental emissions, and operating and production costs. The research gap refers to the lack of a model to aggregate these aspects simultaneously. The objective of the research was to develop a CQ-LCA model (Cost–Quality–Life Cycle Assessment) supporting the creation of alternative product solutions and their evaluation in terms of the following: (i) environmental impact in the life cycle (LCA), (ii) quality, and (iii) production and/or purchase costs. The model was developed in seven main stages and tested for electric motorcycles and their ten prototypes, which are examples of modern products that convert electrical energy into mechanical energy. Using the EDAS method, the quality of electric motorcycle prototypes was calculated. Then, by the LCA method according to ISO 14040, the CO₂ emissions were estimated and modelled adequately to quality change. Next, by the parametric model based on the static method and the cost value function, including the nominal least squares method, the cost was estimated adequately to quality and environmental change. The model provided a qualitative and quantitative interpretation of electric motorcycle prototypes (CQ-LCA), allowing for the consideration of product characteristics, such as engine power, charging time, and battery capacity, but also environmental impacts and costs. The originality is the provision of a multi-aspect morphological analysis, after which different scenarios of product solutions. The model can be useful for various commonly used energy-converting products. Full article