Solid Fuels Research Articles

Predicting calorific value and ash content of sand shrub using Vis-NIR spectra and various chemometrics

Calorific value (CV) reflects the ability of material flow and energy conversion of plants, which is the key indices of combustion properties for utilization and development of energy plants. However, the commonly used method for CV determination of solid fuels is bomb calorimetry in the laboratory using powder samples, which hinders the capability of rapid and non-destructive prediction for a large-scale samples in a natural environment. Visible and near infrared spectroscopy (Vis-NIR) has been widely proposed as a replace for laboratory determination in properties prediction. However, chemometrics are essential for spectral analysis. Various chemometrics including competitive adaptive reweighted sample (CARS), lifting wavelet transform (LWT), successive projections algorithm (SPA), and convolutional neural networks (CNNs) optimized by whale optimization algorithm (WOA) were employed to optimize models. Additionally, canopy spectra were measured in the field instead of powder samples’ spectra collecting from laboratory. The results demonstrated that CARS-WOA-CNN was the best to predict CV and ash content (AC) with R2 of 0.858 and 0.751, respectively. Compared to raw full spectra, spectral dimension was reduced from 2048 to 93 and 22 for CV and AC, respectively. Overall, this study provided a meaningful strategy for harvest planning and assessing value of biomass in the field.

Emission of Intermediate Volatile Organic Compounds from Animal Dung and Coal Combustion and Its Contribution to Secondary Organic Aerosol Formation in Qinghai-Tibet Plateau, China.

Intermediate volatility organic compounds (IVOCs) are important precursors to secondary organic aerosols (SOAs), but they are often neglected in studies concerning SOA formation. This study addresses the significant issue of IVOCs emissions in the Qinghai-Tibetan plateau (QTP), where solid fuels are extensively used under incomplete combustion conditions for residential heating and cooking. Our field measurement data revealed an emission factor of the total IVOCs (EFIVOCs) ranging from 1.56 ± 0.03 to 9.97 ± 3.22 g/kg from various combustion scenarios in QTP. The markedly higher EFIVOCs in QTP than in plain regions can be attributed to oxygen-deficient conditions. IVOCs were dominated by gaseous phase emissions, and the primary contributors of gaseous and particulate phase IVOCs are the unresolved complex mixture and alkanes, respectively. Total IVOCs emissions during the heating and nonheating seasons in QTP were estimated to be 31.7 ± 13.8 and 6.87 ± 0.45 Gg, respectively. The estimated SOA production resulting from combined emissions of IVOCs and VOCs is nearly five times higher than that derived from VOCs alone. Results from this study emphasized the pivotal role of IVOCs emissions in air pollution and provided a foundation for compiling emission inventories related to solid fuel combustion and developing pollution prevention strategies.

Repurposing lignin rich biorefinery waste streams into the next generation of sustainable solid fuels

Value added lignin rich waste sludges from biorefinery processes are, as yet untapped valuable feedstocks that can be reformed into clean, high quality solid fuels. By water washing sludges produced from base hydrolyzed waste, a material stripped of water-soluble alkali and alkaline earth metals (ash) can be obtained. This work shows how leached bagasse, barley and wheat straw sludges can be valorised into clean, low ash solid biofuels that can be used to supplement global energy demands. Repurposed lignin rich sludges of 1.00–2.00 mm particle size feedstocks were found to exhibit calorific values +17.3 %, +16.8 % and +11.7 % for bagasse, wheat, and barley straw sludges, respectively higher than their untreated waste counterparts. Additionally, by employing densification in the absence of a binder, <0.25 mm particles of leached sludge feedstocks were found to experience 16.0 % (bagasse), 12.0 % (wheat) and 4.0 % (barley) increases to their calorific values. This provides options for sustained energy from waste production and consumption campaigns, diversifying feedstock options for green solid fuels

Analysis and projections of disease burden for different risk factors and sexes of ischemic stroke in young adults in China

To estimate the rate of death, and disability-adjusted life years (DALYs) and project the disease burden of ischemic stroke due to relevant risk factors in young adults age 20–49 years by sex in China. Data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 were used. The age-standardized mortality (ASMR), age-standardized DALYs rate (ASDR), and estimated annual percentage changes (EAPC) were calculated to evaluate the temporal trends from 1990 to 2019. We also used the NORDPRED model to predict ASMR for ischemic stroke due to related risk factors in Chinese young adults over the next 10 years. From 1990 to 2019, the general age-standardized mortality [from 2.39 (1.97 to 2.99) in 1990 to 1.8 (1.41 to 2.18) in 2019, EAPC = − 1.23] and DALYs rates (from 171.7 (140.34 to 212.36) in 1990 to 144.4 (114.29 to 177.37) in 2019, EAPC = − 0.86) decreased for ischemic stroke in young adults in China. ASMR and ASDR decreased for all level 1 risk factors (including behavioral, environmental/occupational, and metabolic) from 1990 to 2019, with the slightest decrease for metabolic risks [ASMR from 1.86 (1.39 to 2.41) in 1990 to 1.53 (1.15 to 1.92) in 2019, ASDR from 133.68 (99.96 to 173.89) in 1990 to 123.54 (92.96 to 156.98) in 2019] and the largest decrease for environmental/occupational risks [ASMR from 1.57 (1.26 to 1.98) in 1990 to 1.03 (0.78 to 1.29) in 2019, ASDR from 110.91 (88.44 to 138.34) in 1990 to 80.03 (61.87 to 100.33) in 2019]. In general, high body-mass index, high red meat intake, and ambient particulate matter pollution contributed to the large increase in ASMR and ASDR between 1990 and 2019. Significant reductions in ASMR and ASDR were observed in low vegetables intake, household air pollution from solid fuels, lead exposure, and low fiber intake. In addition, there were sex differences in the ranking of ASMR attributable to risks in ischemic stroke. The disease burden of ischemic stroke attributable to relevant risk factors in young adults in China is greater and has a faster growth trend or a slower decline trend in males than in females (except for secondhand smoke). The apparent increasing trend of ASMR attributable to high fasting plasma glucose, high systolic blood pressure, high body-mass index, and high red meat intake was observed in males but not in females. The projected analysis showed an increasing trend in ASMR between 1990 and 2030 for all specific metabolic risks for males, but a decreasing trend for females. ASMR attributable to ambient particulate matter pollution showed an increasing trend from 1990 to 2030 for both males and females. The burden of ischemic stroke in young adults in China showed a downward trend from 1990 to 2019. Specific risk factors associated with the burden of ischemic stroke varied between the sexes. Corresponding measures need to be developed in China to reduce the disease burden of ischemic stroke among young adults.

Probing microscale crystallization phenomena: Transforming waste slags into riches

Metal smelting and combustion of solid fuels produce significant quantities of waste slag, leading to issues such as land occupation and environmental pollution. Understanding and controlling the microscale crystallization phenomena of these slags during thermal treatment is crucial for transforming waste slags into materials suitable for carbon capture or glass ceramics. Previous research has primarily focused on macroscopic crystallization behaviors, significantly advancing the utilization of waste slags in cement clinker production. However, macroscopic results are inadequate for precisely controlling the microscale crystallization behaviors of waste slags. Here, we employed the single hot thermocouple technique to visually explore crystal growth modes, shapes, sizes, numbers, and translational rates of the crystal growth front in a representative blast furnace slag under various isothermal temperatures. The results revealed that crystals exhibited five modes as the isothermal temperature gradually increased, including equiaxed, equiaxed & columnar, columnar, columnar & planar, and planar. Moreover, the translational rate of the crystal growth front increased from 0.011 μm·s−1 to 43.7 μm·s−1 with an increase in the isothermal temperature. Simultaneously, the number of crystals decreased from around 104 to 100 μm−2. On this basis, correlations between microscale crystallization behaviors and isothermal temperature were established to fill the current gap.

A Case Study on Electric Vehicles as Nationwide Battery Storage to Meet Slovenia’s Final Energy Consumption with Solar Energy

Despite the global importance of solar energy, its variability requires energy storage to balance production during peak and off-peak periods. Moreover, the transport sector is undergoing a global transition from internal combustion engines to electric vehicles. Since vehicles are idle 95% of the time, electric vehicle batteries, when connected to a grid, can effectively regulate intermittent photovoltaics using vehicle-to-grid technology. This conceptual study investigates the feasibility of a nationwide energy infrastructure that relies solely on solar energy, replacing other electricity sources, such as solid fuels, petroleum products, and natural gas, and utilizes electric vehicles as the sole battery energy storage system. This study aims to demonstrate the significant potential and benefits of such collaboration. The theoretical study combines historical data, assumptions, and conditions to build a simulation model that is modelled similarly as in previous conceptual studies of nationwide energy systems based solely on photovoltaics and electric vehicles, referenced in this article. In Slovenia, the total surface size suitable for the installation of photovoltaic systems is estimated to be 280 km2. The calculations show that a surface size of 217 km2 for photovoltaic systems can produce enough energy to cover Slovenia’s entire energy demand, Slovenia’s final energy consumption. However, simulations comparing photovoltaic production, total energy consumption (electricity, solid fuels, etc.), and the capacity of electric vehicle batteries show that a surface size of more than 500 km2 with photovoltaic systems and a 200% share of electric vehicles in the Slovenian vehicle fleet in 2022 will provide satisfactory results. Therefore, for a country like Slovenia, in addition to a solar power plant with a surface size of 280 km2, additional renewable energy sources are needed to cover the total energy demand, as well as additional battery energy storage systems in addition to electric vehicles.

Machine Learning Techniques for Spatio-Temporal Air Pollution Prediction to Drive Sustainable Urban Development in the Era of Energy and Data Transformation

Sustainable urban development in the era of energy and digital transformation is crucial from a societal perspective. Utilizing modern techniques for analyzing large datasets, including machine learning and artificial intelligence, enables a deeper understanding of historical data and the efficient prediction of future events based on data from IoT sensors. This study conducted a multidimensional historical analysis of air pollution to investigate the impacts of energy transformation and environmental policy and to determine the long-term environmental implications of certain actions. Additionally, machine learning (ML) techniques were employed for air pollution prediction, taking spatial factors into account. By utilizing multiple low-cost air sensors categorized as IoT devices, this study incorporated data from various locations and assessed the influence of neighboring sensors on predictions. Different ML approaches were analyzed, including regression models, deep neural networks, and ensemble learning. The possibility of implementing such predictions in publicly accessible IT mobile systems was explored. The research was conducted in Krakow, Poland, a UNESCO-listed city that has had long struggle with air pollution. Krakow is also at the forefront of implementing policies to prohibit the use of solid fuels for heating and establishing clean transport zones. The research showed that population growth within the city does not have a negative impact on PMx concentrations, and transitioning from coal-based to sustainable energy sources emerges as the primary factor in improving air quality, especially for PMx, while the impact of transportation remains less relevant. The best results for predicting rare smog events can be achieved using linear ML models. Implementing actions based on this research can significantly contribute to building a smart city that takes into account the impact of air pollution on quality of life.

SEM/EDX and FTIR/ATR Behavior of Ammonium Perchlorate Under Accelerated Aging in a New Solid Rocket Motor Fuel Composition with Superior Explosive and Mechanical Performance

Abstract The oxidation potential of perchlorates is high, which makes this material suitable for fuels with high specific impulse. Perchlorates are characterized by a ClO4- moiety/anion in their molecular structure and are crystalline materials used in the formation of solid fuels. Ammonium perchlorate (AP) particle size and shape influence the manufacturing process of fuels and their burning rate. The physical and chemical processes that can occur in the natural degradation process of composite fuels are related to molecular reactions and diffusion phenomena governed by kinetic processes and can be accelerated by increasing the temperature. The paper presents studies carried out by scanning electron microscopy and infrared spectrometry on the behavior of ammonium perchlorate in the new composite material of solid rocket motor fuel under the effect of high temperature, in the range of 65-85οC, at regular time intervals. The self-initiation temperature was also determined, with a temperature rise rate controlled at 5ºC/minute. It is very likely that these accelerated aging studies will show the changes that occur in the stability, sensitivity, mechanical and functional properties of fuels during their lifetime.

Geographic and sociodemographic variations in disease burden, epidemiological trends, and risk factors of early-onset lung cancer: A global analysis.

11169 Background: Exploring the emerging trend of early-onset lung cancer (EOLC) burden is pivotal for guiding the implementation of preventive strategies among young adults. We aimed to provide a comprehensive examination of the geographic and sociodemographic variations in the disease burden, along with epidemiological trends and risk factors associated with EOLC over the past three decades. Methods: EOLC refers to lung cancer diagnosed in individuals aged 20-49 years. Utilizing the GBD 2019 data, we estimated the age-standardised incidence, mortality, and disability-adjusted life years (DALYs) rates for EOLC by sex, socio-demographic index (SDI) quintiles, and geographical location for the period from 1990 to 2019. We investigated the relationships between concomitant risk factors and EOLC incidence at national level, and calculated the DALYs attributable to risk factors. The relative contribution of population growth, population ageing, and epidemiological changes to the variations in burden of EOLC over study period was measured using the decomposition analysis. Incidence was forecast to 2040 using the Bayesian age-period-cohort model. Results: A total of 135,704 EOLC cases, equating to a age-standardised incidence rate of 4.0 (95% UI 3.6 to 4.3) per 100,000, were estimated in 2019 worldwide and was the second leading cause of cancer death among young adults, with higher disease burden occurred in males and those from middle and high-middle SDI regions. An overall decreasing trend in burden of EOLC was observed globally; such trends were more pronounced among males and followed a gradient across SDI levels, with the greater decrease observed in high and high-middle SDI regions. Sex, tobacco smoking prevalence, per capita cigarette-equivalent estimates, average age of smoking initiation, ambient ozone pollution, and GDP per capita were independently and significantly associated with EOLC incidence at the population level. Smoking remained the top contributor to burden of EOLC, with the exception of Andean Latin America, North Africa, and the low SDI regions, where ambient particulate matter pollution and household air pollution from solid fuels ranked as the foremost attributable risk factors. Population growth was the primary driver behind the global increase in EOLC cases in low and low-middle SDI regions, while epidemiological changes accounted for the most substantial reduction in EOLC cases across most regions. The global incidental cases of EOLC was projected to increase by 31.1% in 2040, with a more pronounced increase in females and those from high-middle and middle SDI locations. Conclusions: Our findings underscore significant geographic and sociodemographic disparities in the epidemiological burden of EOLC, emphasizing the necessity for policymakers to devise and apply region-specific, evidence-driven preventive strategies.

Development of solid recovery fuel for power generation with bacterial bio-drying of municipal solid waste in Lombok Island West Nusa Tenggara

Abstract The growth of waste in big cities in Indonesia increases sharply every year. The Government’s ability to manage solid waste only reaches 40.09% in urban areas and 1.02% in rural areas, so the right policies are needed so that Municipal Solid Waste (MSW) does not save potential problems that will impact the future. The waste problem is no longer just a matter of cleanliness and the environment but has become a social problem that has the potential to cause conflict. The most likely solution to solving the MSW problem is to use it as a source of alternative fuel, which can be done by a mechanical-biological treatment technology into Solid Recovery Fuel (SRF). The proposed SRF processing method is straightforward and requires a little technology; thus, it could be developed at the community level. The MSW is collected and processed by communities and then sold to power plants or factories or used in communities to replace solid fuels such as wood or charcoal. Compared with the standard RDF and SRF specifications, MSW SRF falls under medium-grade Refuse Derived Fuel (RDF) or SRF specifications. Further comparison with coal, water hyacinth SRF, and sorghum shows that MSW SRF has several advantages, such as low fixed carbon, sulfur, and moisture, that could be beneficial for combustion performance, which concludes that MSW has potential and meet the specification as an alternative fuel for thermal power plant or other industry that utilizes thermal energy. This paper proposes a processing methodology for municipal solid waste into alternative energy. The method could guide local people in using biomass resources to improve local economic prosperity.

Pengaruh Metode Pengarangan dan Ukuran Partikel Terhadap Kualitas Briket Cangkang Kelapa Sawit

One renewable energy source is biomass. Biomass is organic matter that generally comes from plants. Bio charcoal briquettes are solid fuels and come from the remnants of biomass that are charred. This study aims to examine the effect of authoring method and particle size on briquette quality. This study used the method of torrefaction authoring at temperatures of 2000C, 3000C and manual authoring. The particle size of charcoal is varied by 20 and 40 mesh. The parameters tested are moisture content, calorific value, bound carbon content, vapor content, ash content, density and combustion rate. The results showed that the type of torrefaction authoring was able to improve the quality of briquettes through increasing calorific value, bound carbon content and reducing water content and evaporating substances and the production of liquid smoke products by 48.5%. The quality of briquettes from the temperature of 3000C charcoal size 20 mesh briquettes meets the quality I of SNI 01-6235-2000 with calorific values and water content of 6841 Cal/g, 3.52% respectively and the content of bound carbon, vaporizers, ash, density and combustion rate are 50.06%, 37.59%, 8.13%, 1.71 g/cm3, 0.076 g/min.

Cooking-related burn injuries at Muhimbili National hospital and knowledge about safe use of liquefied petroleum gas in Dar Es Salaam, Tanzania: A cross-sectional study

BackgroundCooking-related burn injuries are a public health problem, and may be even more likely to occur in countries that are experiencing a transition to cleaner cooking fuels like liquefied petroleum gas (LPG). The risk of burns from cooking with these newer fuels, and safety measures or training to prevent injuries, is not well documented. This study examines the burden of burn injuries and burn prevention education provided to consumer by LPG stove and cylinder vendors. MethodsA cross-sectional study was conducted among 100 burn patients admitted to Muhumbili National Hospital from February 2022 to January 2023 to assess cooking-related burns. ResultsWe found that among 377 patients with all burn injuries, 100 (26.5%) were cooking-related, with charcoal (51%) and LPG (35%) stoves being the most reported. Females (61%) were more affected than males (39%), and lower education levels were more likely to be associated with burn injuries. Of all burn patients admitted, 57 (15.1%) died. Among those who experienced a cooking-related burn, 7 (7%) died. Children were more affected (59%) by any cooking-related burn injuries, but adults were more likely to experience LPG-related burns (56%). Small cylinders with a burner placed directly over the cylinder as one unit, without a connecting hose, caused less injury than stoves using a larger cylinder with a rubber connecting hose. ConclusionSafety measures for LPG stoves and fuels, including policies to increase awareness and prevent burn injuries, must be prioritized in countries like Tanzania that are transitioning from solid fuels to LPG fuels for cooking.

Estimating the higher heating value and chemical exergy of solid, liquid, and natural gas fossil fuels

The escalating global population has spurred a significant surge in energy demand. While developed nations pivot towards renewable energy sources, many developing countries rely heavily on fossil fuels. Understanding these fuels' higher heating value and chemical exergy is crucial for energy analysis, second law analysis, optimal energy generation, and resource conservation.This study introduces an adaptable analytical method for calculating the higher heating value and chemical exergy of fossil fuels (coal, oil, natural gas). It demonstrates minimal error, with approximately a 3.5 % deviation for higher heating value and 8 % for chemical exergy compared to empirical relations.Novel relationships, developed through linear regression and computer programming, address research gaps and exhibit a maximum 2.6 % difference for higher heating value and 5.4 % for chemical exergy compared to existing empirical references. These contributions will greatly benefit energy professionals and engineers.This research addresses critical gaps in current methodologies for estimating higher heating value and exergy by offering a compact form for calculating various fossil fuels within a wide range of Carbon-to-Hydrogen ratios (3–105). Additionally, it provides specific equations applicable to both mole and mass fractions for natural gases, primarily composed of methane, with mole fractions ranging from 55 % to 99 %.

Impact of indoor air pollution on DNA damage and chromosome stability: a systematic review.

Indoor air pollution is becoming a rising public health problem and is largely resulting from the burning of solid fuels and heating in households. Burning these fuels produces harmful compounds, such as particulate matter regarded as a major health risk, particularly affecting the onset and exacerbation of respiratory diseases. As exposure to polluted indoor air can cause DNA damage including DNA sd breaks as well as chromosomal damage, in this paper, we aim to provide an overview of the impact of indoor air pollution on DNA damage and genome stability by reviewing the scientific papers that have used the comet, micronucleus, and γ-H2AX assays. These methods are valuable tools in human biomonitoring and for studying the mechanisms of action of various pollutants, and are readily used for the assessment of primary DNA damage and genome instability induced by air pollutants by measuring different aspects of DNA and chromosomal damage. Based on our search, in selected studies (in vitro, animal models, and human biomonitoring), we found generally higher levels of DNA strand breaks and chromosomal damage due to indoor air pollutants compared to matched control or unexposed groups. In summary, our systematic review reveals the importance of the comet, micronucleus, and γ-H2AX assays as sensitive tools for the evaluation of DNA and genome damaging potential of different indoor air pollutants. Additionally, research in this particular direction is warranted since little is still known about the level of indoor air pollution in households or public buildings and its impact on genetic material. Future studies should focus on research investigating the possible impact of indoor air pollutants in complex mixtures on the genome and relate pollutants to possible health outcomes.

ДОСВІД ВИКОРИСТАННЯ ЗОЛИ ВИНЕСЕННЯ В ЯКОСТІ НАПОВНЮВАЧІВ В АСФАЛЬТОБЕТОНІ

Introduction. Fly ash is a by-product of electricity generation using coal or other solid fuels. It is a material containing various chemical compounds such as calcium, potassium and sodium oxides. Since fly ash is not a biodegradable material and can have a negative impact on the environment, its use in asphalt concrete is one of the possible ways to reduce waste and improve the environmental situation, as well as reduce the use of natural resources. Problem statement. Road construction with asphalt pavements requires a large number of components of these mixtures. In this regard, the need for scarce carbonate mineral filler is growing. Therefore, it is advisable to consider research aimed at studying industrial by-products, in particular fly ash, in order to use them as mineral fillers for asphalt concrete. Objective. To analyze the existing experience of using fly ash as a mineral filler in the production of asphalt mixtures for further implementation and improvement of environmental safety and performance characteristics of road pavements due to new road construction materials. Materials and methods. Analysis of information sources and experience in the use of industrial waste as mineral filler, study of requirements for materials and their composition.

Evaluation of the applicability of carbon-based materials for arsenic removal from flue gases

Arsenic is an highly toxic element which may be released into the atmosphere during the combustion of solid fuels. This paper verifies the possibility of using char from tires CT and lignite dust LD as materials for the adsorption of gaseous forms of As. The source of the gaseous forms of arsenic was coal combustion under laboratory conditions. Adsorption tests included both different sorbent bed temperatures (120–180°C) and various flue gas compositions (resulting from the combustion of bituminous and lignite coals). It was shown that sorption temperature did not affect the arsenic removal efficiency for both analysed sorbents. The average As removal efficiency for tire char and lignite dust was 88 and 92%, respectively. The composition of the burned coal, and thus the composition of the flue gas, significantly influences the efficiency of Asgas adsorption. While for LD the level of As removal was still high (more the 90%), the sorption of Asgas by tire char from the flue gas when lignite was burned was less effective (the efficiency was below 80%). It was additionally indicated via a leachability test that "used" CT could be safely disposed of while LD would require appropriate management. Based on the comparison of the performance of CT and LD with commercial AC activated carbon and the differences in their market price, it can be concluded that the studied alternative sorbents are competitive with AC.

Combustion Characteristics of Vat-Photopolymerized Fuels with a Spiral Star Port for Hybrid Propulsion.

Despite hybrid rocket motors offering distinct advantages over solid or liquid rocket motors, their low regression rate and insufficient combustion efficiency remain significantly unimproved. This study focuses on the effects of the helix lead on the regression rate distribution and combustion efficiency of vat-polymerized fuel grains with a spiral star port for a hybrid rocket. Both experimental and numerical investigations were conducted to study the combustion characteristics and regression rate distribution of three-dimensional (3D) print grains. Spiral star grains with varying helix leads of 60, 90, and 120 mm were fabricated using light-curing 3D printing technology. A 3D simulation model was developed to obtain the temperature distribution, species mass distribution, and combustion efficiency. Furthermore, firing tests were performed on a two-dimensional radial hybrid combustion test stand to measure the regression rate. Digital image processing of computed tomography images was used to determine the regression rate. Simulation results indicated that the spiral star grain port helps to improve the combustion efficiency compared with those seen with round tube and straight star port grains. With an increase in the axial distance, the flame zone gradually shrinks, and the smaller the helix lead, the faster the shrinkage. At a mass flow rate of 1.50 g/s for oxygen, the regression rate of the spiral star grains is significantly higher than that of the straight star grain and the conventional round tubular grains, and the regression rate gradually increases with a decrease in the helix lead. This finding is expected to solve the problem of the low regression rate of solid fuels with spiral star pore-shaped grains prepared by the light-curing 3D printing method.

A Survey of Flow Field and Combustion Characteristics under Subatmospheric Pressure

This paper presents a summary of and introduction to research on high-altitude and subatmospheric combustion concerning turbine and scramjet engines. The investigation includes theoretical analysis, experimental studies, and numerical simulations. The analysis encompasses the flow field structure, fuel atomization, and combustion performance. Subsequently, recent research on the combustion performance of liquid fuels, solid fuels, and gaseous fuels under high-altitude and low-pressure plateau environments is reviewed. This includes an evaluation of flame height, flame temperature, combustion rate, fire spread rate, and heat radiation flux. Additionally, combustion performance prediction models for high-altitude environments based on experimental and theoretical analysis have been introduced. Lastly, issues in subatmospheric combustion in the aerospace and plateau fire fields are presented based on the current research.

Transition to cooking with clean fuels in rural households of India: Studying the effect of policy and other factors

The seventh UN Sustainable Development Goal is access to clean and affordable energy and cooking with clean fuels is essential to reduce the disease burden associated with indoor air pollution from solid fuel use. The Pradhan Mantri Ujjwala Yojana (PMUY) was launched in 2016 to target poor households belonging to disadvantaged caste and class categories and provided free LPG connections to these households to make clean energy accessible. This paper used binomial logistic regression modelling with rural household data from two rounds of the NFHS conducted in 2015–16 and 2019-21, to find whether a targeted intervention like the PMUY is enough to increase the use of clean fuels over solid fuels among rural households in India. The change in the effect of socio-economic and demographic factors affecting the choice of clean fuels for cooking are also studied to find their relative contribution along with the effect of policy. This analysis finds that targeted interventions have significant impact in bringing a positive change in use of clean fuels for cooking in rural households in India but there are other social and economic factors which also play an important role in sustaining the transition to clean cooking.

Effects of indoor air pollution from household solid fuel use on the risk of gastrointestinal and liver diseases in middle aged and elderly adults

Solid fuels are widely used in China and increase the concentrations of indoor air pollutants. Nevertheless, there is limited longitudinal evidence linking solid fuel use and Gastrointestinal (GI) and liver diseases. This study aimed to prospectively investigate the association between household solid fuel use and the risk of GI and liver diseases in middle aged and elderly adults. This work was based on the China Health and Retirement Longitudinal Study (CHARLS). Longitudinal data incorporate with cross-sectional data were analyzed. Compared with individuals using clean fuel for cooking, solid fuel users were observed to have higher risk of GI diseases (OR in 2011, 2013, 2015, 2018 wave separately: 1.37, 95 % CI: 1.24–1.50, P < 0.001; 1.24, 95 % CI: 1.11–1.39, P < 0.001; 1.18, 95 % CI: 1.06–1.33, P < 0.001; 1.23, 95 % CI: 1.04–1.45, P < 0.05). The associations between solid fuel use and liver diseases were not significant in most of the groups. Participants transforming from solid to clean cooking fuels had lower risk of GI and liver diseases than persistent solid fuel users. Moreover, biomass cooking fuel users were at a significant higher risk of both liver and GI diseases compared with clean fuel users. Overall, household solid fuel use, especially for cooking, was related to higher risk of GI and liver diseases, while switching from solid to clean fuels could reduce this risk. Using biomass for cooking was identified to be more associated with the increasing risk of GI and liver diseases than cooking with coal.