Hasil untuk "Fuel"

V. V. Lebedev

A comprehensive study of the current state and development prospects of the heat and power industry in Russia has been conducted. The structure of fuel and energy resources consumption, as well as the role of heat supply in ensuring the sustainable functioning of the country’s economy have been analyzed. Special attention has been paid to the intersectoral nature of thermal energy and its impact on industry, housing and communal services, and the social sphere. The high energy intensity of the industry has been emphasized, and the need to optimize the processes of generating, distributing, and consuming thermal energy has been pointed out. Various types of heat supply systems – centralized and decentralized – have been studied in terms of their efficiency, environmental friendliness, and economic feasibility. The current dynamics of these systems development in the context of regional specifics and climatic conditions has been described. The key issues of the industry have been analyzed, including uneven distribution of generating capacities, high level of physical wear of equipment, significant losses of thermal energy in distribution networks, as well as insufficient transparency and accuracy of consumption accounting. An important place in the study is devoted to the issues of tariff formation, and both technical and economic factors have been considered, including excess losses, excess costs, the investment component of tariffs, and the need to modernize infrastructure. A forecast of the Russian thermal power industry development has been proposed, and the main barriers hindering its modernization have been identified. Possible ways to increase the energy and economic efficiency of the industry in the face of rising fuel prices and stricter environmental requirements have been listed.

Apriliana Margawadi Kenanga, Widayat, Widodo Agung Suedy Sri

In Indonesia, coal-fired power plants (CFPP) account for nearly 70% of the nation’s electricity supply, contributing significantly to global warming. Biomass co-firing program for CFPP offers a potential solution. This study analyzes the impact of co-firing between blending of Low Rank Coal (LRC) with Medium Rank Coal (MRC) and wood pellet biomass, on the performance of 615 MW capacity CFFP. Using simulations with Cycletempo software, the research examines operational parameters such as plant efficiency, the performance of auxiliary equipment, and a techno-economic analysis focusing on carbon trading. The biomass co-firing tested reached up to 50%, with results indicating that increasing biomass content tends to reduce overall plant efficiency. Results indicate that at 100% load, the plant can accommodate up to 10% biomass co-firing, and at 75% load, it can handle up to 30%. Co-firing beyond 30% requires increased pulverizer power for stable operation. From techno-economic perspective, while co-firing reduces greenhouse gas emissions and generates benefits from carbon trading, the operational costs associated with fuel under co-firing are not yet fully profitable. This study offers guidance on increasing the co-firing ratio as part of the energy transition towards net zero emissions 2060 and provides recommendations for optimizing fuel mixtures in CFFP.

Tianlin Shen, Jilai Cui, Shuo Yang et al.

Plant-soil-microbe interactions can affect plant growth, development, and health. Plants can secrete bioactive molecules into the rhizosphere to alter the soil microbiota, further influencing plant growth. In this paper, the effects of flavonols secreted by tea roots on the remodeling of rhizosphere bacteria and on growth of tea plants were explored. Aluminum treatment significantly promoted the growth of tea plants, the accumulation of flavonols glycosides in the roots and the secretion of flavonols glycosides from roots. 16S rRNA analysis indicated that after aluminum treatment, the rhizosphere bacteria Burkholderia of the Proteobacteria phylum were significantly enriched. Compared to 'Longjin43' (LJ43), in roots of 'Huangjinye' (HJY), more flavonols were accumulated, so did in the root exudates. Moreover, Burkholderia in the rhizosphere of 'HJY' was significantly enriched. The results of correlation analysis indicated that the abundance of Burkholderia was significantly positively correlated with the secretion of flavonols under aluminum treatment or in different tea cultivar. Then 0.05 mM kaempferol were exogenous application to confirm the growth-promoting effect of flavonols on tea plants and the recruitment of Burkholderia in rhizosphere of tea roots. In conclusion, tea roots secrete flavonol glycosides into the rhizosphere soil, which can recruit Burkholderia and further promote the growth of tea plants. This study laid foundation for the subsequent development of bacterial fertilizers to promote the growth of tea plants.

Vedant Singh, Aishwarya V.M., Sriprasath V.J. et al.

Summary: Green hydrogen (GH) offers a sustainable fuel alternative for addressing global energy and climate goals. This study evaluates GH viability across five dimensions: technological advancement, economic feasibility and market potential, environmental impacts and resources dynamics, policy regulatory frameworks, and interdisciplinary collaborations. Recent advancements in electrolysis technologies and artificial intelligent driven process optimization have enhanced production efficiency and resource management. Despite increasing investments, GH faces challenges such as high electricity demand, water usage, and infrastructure constraints. A regional assessment using the Green Hydrogen Feasibility Index (GHFI) indicates that countries such as China, Germany, and the USA lead in readiness due to robust policies and investment, while others face implementation issues. The finding emphasizes the need for coordinated global regulation, infrastructure development, and digital integration to enhance GH scalability and sustainability. This work contributes a comprehensive framework for assessing GH deployment and highlights strategies to accelerate its role in achieving a net-zero energy future.

Antonia Oikonomou, Marilou Avramidou, Emmanouil Psomiadis

Wildfires increasingly threaten Mediterranean landscapes, particularly in regions like Attica, Greece, where urban sprawl, agricultural abandonment, and climatic conditions heighten the risk at the Wildland–Urban Interface (WUI). The Mediterranean basin, recognized as one of the global wildfire “hotspots”, has witnessed a steady increase in both fire severity, frequency, and burned area during the last four decades, a trend amplified by urban sprawl and agricultural land abandonment. This study represents the first integrated, region-wide mapping of the WUI and associated wildfire risk in Attica, the most densely urbanized area in Greece and one of the most fire-exposed metropolitan regions in Southern Europe, utilizing advanced techniques such as Earth Observation and GIS analysis. For this purpose, various geospatial datasets were coupled, including Copernicus High Resolution Layers, multi-decadal Landsat fire history archive, UCR-STAR building footprints, and CORINE Land Cover, among others. The research delineated WUI zones into 40 interface and intermix categories, revealing that WUI encompasses 26.29% of Attica, predominantly in shrub-dominated areas. An analysis of fire frequency history from 1983 to 2023 indicated that approximately 102,366 hectares have been affected by wildfires. Risk assessments indicate that moderate hazard zones are most prevalent, covering 36.85% of the region, while approximately 25% of Attica is classified as moderate, high, or very high susceptibility zones. The integrated risk map indicates that 37.74% of Attica is situated in high- and very high-risk zones, principally concentrated in peri-urban areas. These findings underscore Attica’s designation as one of the most fire-prone metropolitan regions in Southern Europe and offer a viable methodology for enhancing land-use planning, fuel management, and civil protection efforts.

Kensuke Sato, Miwa Tomioka, Masahiro Akiyama et al.

Summary: While fermentable oligo- and di-, mono-saccharides and polyols (FODMAPs) have been implicated in exacerbating inflammatory bowel disease (IBD) symptoms, the exact influence of FODMAPs on gut microbiota and inflammation is unclear. Here, we show that sorbitol, a polyol, exacerbates colitis in mice induced by dextran sodium sulfate (DSS). Sorbitol increases the expression of inflammatory genes, including Il1b, in the colon, associated with M1 macrophage-related genes elevated in IBD patients. Indeed, sorbitol treatment leads to a higher proportion of M1 macrophages in the colon, worsening colitis, which is reversed in interleukin-1β (IL-1β)-deficient mice and mitigated with antibiotic treatment. Sorbitol alters the composition of gut microbiota and metabolites, with Prevotellaceae and tryptamine positively correlated with colonic M1 macrophages. Tryptamine stimulation enhances M1 macrophage polarization. Taken together, polyol consumption activates intestinal macrophages by altering the gut microbiome, which in turn promotes intestinal inflammation.

Eyal Shay

Shweta Singh, Manish Kumar, Rahul Kumar

Abstract Emerging wireless communication networks, exemplified by the evolution from 5G to subsequent technologies, necessitate extensive connectivity among myriad devices to fuel the ongoing technological progress. However, the magnitude of this network demands an extensive power source, requiring an advanced and sustainable system to be practically deployable. This study introduces a cutting‐edge system utilising ambient RF signals for both wireless information transfer (WIT) and wireless power transfer. The proposed system addresses the energy deficiencies of billions of low‐powered wireless devices within the network. Wireless‐powered communication networks (WPCN) and simultaneous wireless energy and power transfer (SWIPT) technologies, operating on ambient RF signals, provide a solution for the energy requirements of these devices. Harvesting energy from ambient RF signals is pivotal for the signal transmissions of WPCN and SWIPT systems. The research focuses on enhancing the efficiency and feasibility of such systems, emphasising aspects like maximising energy efficiency (EE) and improving outage performance (OP). The paper underscores the ubiquitous connectivity resulting from node mobility and delves into the emerging models of WPCN and SWIPT, along with collaborative technologies integrated with these models. It explores resource allocation (RA), multiple‐input multiple‐output (MIMO) technology in the context of WPCN, and various aspects of relaying operations, including SWIPT‐MIMO and SWIPT receiver architecture. Conclusively, the comprehensive survey affirms that leveraging ambient RF signals for WIT and power transfer can significantly enhance EE, OP, RA, and overall network capabilities. This improvement positions the proposed system as a promising solution for meeting the connectivity demands of future wireless communication technologies.

Mbanwei Divine Kobbi, Njimboh Henry Alombah, Ngwa Martin Ngwabie

Electric vehicles have advantages such as reduced maintenance and fuel costs compared to internal combustion engines. However, their limited driving range still hinders their widespread adoption compared to internal combustion engines. Harvesting wasted energies through vibrations in electric vehicles is a good approach to complement the energy of their batteries. Space constraints in electric vehicles require devices with high power output per unit volume. This study aimed to design a novel vibration energy harvesting using the geometrical model for electric vehicles. Different configurations and their performance in maximum flux linkage, electromagnetic coupling coefficient, induced voltage, and generated power were investigated. The modeling, excitement, and analysis were conducted using ANSYS Maxwell software with four configurations under similar conditions. These were the Halbach array with three magnets, one coil, and flat back shield; the Halbach array with three magnets and one coil with a stepped back shield; the double magnet array with two magnets, one coil, and flat back shield; and the fourth one was a double magnet array with two magnets, one coil and stepped back shield. The MATLAB Simulink software was used to obtain further results and power output analysis. The results of the analysis show that the Halbach array with three magnets, one coil, and a stepped-back shield is the best configuration for harvesting energy from vibrations, producing an electromagnetic coupling coefficient of up to 110 Wb/m, a voltage of up to 36 V, and generated power density of 0.13 W/cm. A reasonable increase in output using less volume was obtained compared to the other studies. The energy harvested will be applied in future studies to extend the range of agricultural electric vehicles, reducing farmers’ income spent on fuel and maintenance.

Sattorov Bobonazar, Davlonov Khairulla, Toshmamatov Bobir et al.

In the article, the authors proposed a combined device of a solar dryer-water heater with a heat accumulator (CDSDWHHA) for drying agricultural products using solar energy. As a research object - a connected device of a solar dryer-water heater with a heat accumulator, a drying drum installation, and an additional combined solar water-air heating collector for simultaneous heating of water and air was installed. Drying agricultural products is a technological process that requires a large consumption of thermal energy and fuel-energy resources. The results of the conducted analysis showed that electric heating devices are often used to operate such a system, which are always expensive and not economically acceptable. In this paper, in order to reduce the traditional energy consumption for drying agricultural products, a combined device of solar dryer-water heater with heat accumulator is proposed and experiments were conducted in the meteorological climate of Karshi city. As a result of experimental studies shows the heat load compensation and energy efficiency of the solar water-air heating collector drying device with a heat accumulator in the “water + air” heating mode. The installation efficiency was found to be in the range of 0.66 - 0.72.

Xiaofeng Zeng, Wei Gao, Gengjie Yang

When a high impedance fault (HIF) occurs in a distribution network, the detection efficiency of traditional protection devices is strongly limited by the weak fault information. In this study, a method based on S-transform (ST) and average singular entropy (ASE) is proposed to identify HIFs. First, a wavelet packet transform (WPT) was applied to extract the feature frequency band. Thereafter, the ST was investigated in each half cycle. Afterwards, the obtained time-frequency matrix was denoised by singular value decomposition (SVD), followed by the calculation of the ASE index. Finally, an appropriate threshold was selected to detect the HIFs. The advantages of this method are the ability of fine band division, adaptive time-frequency transformation, and quantitative expression of signal complexity. The performance of the proposed method was verified by simulated and field data, and further analysis revealed that it could still achieve good results under different conditions.

Bogdan Adrian NICOLIN, Ilie NICOLIN

Hydrogen is the most plentiful chemical element in the visible universe. The mass composition of the visible universe is approximately 74% hydrogen, 24% helium, 1% oxygen, and the rest of all other chemical elements is about 1%. Hydrogen has the symbol H and the atomic number 1. It is placed in the first position in Mendeleev's periodic table of elements, in the upper left corner. It is an easily flammable, colorless, tasteless, odorless gas, and in nature, it is found mainly in the form of the diatomic molecule, H 2. With an atomic mass unit of 1.00794, hydrogen is the lightest chemical element. Etymologically, the word hydrogen is a combination of two Greek words hydor and gennan meaning: water producer. Hydrogen (H 2) has a very good calorific value per mass unit 143 MJ/kg which is 3.33 times more than the calorific value of kerosene or diesel fuel. Green hydrogen (clean hydrogen or renewable hydrogen) is produced by electrolysis of water (splitting of water into hydrogen and oxygen) using electricity from renewable sources such as solar energy, wind energy, seawater waves energy, or tidal power. Green hydrogen is an environmentally-friendly power source (no harmful gases). This paper presents recent documentary research by the authors on green hydrogen as an environmentally-friendly power source: for space rocket launches and for hydrogen fuel cells used in the space shuttle as electrical power generators and drinking water generators from launch to return from the space mission; as fuel for a modified turboprop engine (Rolls-Royce and easyJet); as fuel for the European Destinus aircraft using the Jungfrau technology system for a planned hypersonic aircraft using a modified commercial afterburning engine; as fuel for modified gas turbine engines and hydrogen fuel cells to supply electrical power to supplement the gas turbine for the Airbus ZEROe aircraft, etc.

Kristina J. Bartowitz, Eric S. Walsh, Jeffrey E. Stenzel et al.

Climate change has intensified the scale of global wildfire impacts in recent decades. In order to reduce fire impacts, management policies are being proposed in the western United States to lower fire risk that focus on harvesting trees, including large-diameter trees. Many policies already do not include diameter limits and some recent policies have proposed diameter increases in fuel reduction strategies. While the primary goal is fire risk reduction, these policies have been interpreted as strategies that can be used to save trees from being killed by fire, thus preventing carbon emissions and feedbacks to climate warming. This interpretation has already resulted in cutting down trees that likely would have survived fire, resulting in forest carbon losses that are greater than if a wildfire had occurred. To help policymakers and managers avoid these unintended carbon consequences and to present carbon emission sources in the same context, we calculate western United States forest fire carbon emissions and compare them with harvest and fossil fuel emissions (FFE) over the same timeframe. We find that forest fire carbon emissions are on average only 6% of anthropogenic FFE over the past decade. While wildfire occurrence and area burned have increased over the last three decades, per area fire emissions for extreme fire events are relatively constant. In contrast, harvest of mature trees releases a higher density of carbon emissions (e.g., per unit area) relative to wildfire (150–800%) because harvest causes a higher rate of tree mortality than wildfire. Our results show that increasing harvest of mature trees to save them from fire increases emissions rather than preventing them. Shown in context, our results demonstrate that reducing FFEs will do more for climate mitigation potential (and subsequent reduction of fire) than increasing extractive harvest to prevent fire emissions. On public lands, management aimed at less-intensive fuels reduction (such as removal of “ladder” fuels, i.e., shrubs and small-diameter trees) will help to balance reducing catastrophic fire and leave live mature trees on the landscape to continue carbon uptake.

M. Ellis, M. V. Spakovsky, D. Nelson

T. Turrentine, K. Kurani

Z. Zhan, S. Barnett

T. Sterner

Dulcilena de Matos Castro e Silva, Rosa Maria Nascimento Marcusso, Cybelli Gonçalves Gregório Barbosa et al.

In the context of megacities in an urban environment, air quality is an important issue, due to the direct correlation to population's health. The biomonitoring of pollutants can indicate subtle environmental alterations, for that, anemophilous fungi can be monitored for changes in atmospheric conditions related to pollution. In the present study, the concentration of fungi and bacteria in the atmosphere was measured during a specific vehicle fleet reduction in the city of São Paulo, Brazil, from May 24 to 30, 2018, using impactor air samplers. The number of isolated developed colonies was related to atmospheric conditions and the concentration of other air pollutants constantly monitored. Aspergillus, Curvularia, Penicillium, Neurospora, Rhizopus and Trichoderma were identified. The number of colony-forming units increased by approximately 80% during the sampling period in response to environmental changes favored by the fleet reduction. This result implies the relation between fuel emissions, concentration of atmospheric pollutants, and the presence of viable fungal spores in the urban environment, which highlights the importance of combined public policies for air quality in large cities.

M. Perry, T. Fuller

G. Karim