Combustion Period Research Articles

Evidence that modern fires may be unprecedented during the last 3400 years in permafrost zone of Central Siberia, Russia

Recent climate change in Siberia is increasing the probability of dangerous forest fires. The development of effective measures to mitigate and prevent fires is impossible without an understanding of long-term fire dynamics. This paper presents the first multi-site palaeo-fire reconstruction based on macroscopic charcoal data from peat and lake sediment cores located in different landscapes across the permafrost area of central Siberia. The obtained results show similar temporal patterns of charcoal accumulation rates in the cores under study, and near synchronous changes in fire regimes. The paleo-fire record revealed moderate biomass burning between 3.4 and 2.6 ka BP, followed by the period of lower burning occurring from 2.6 to 1.7 ka BP that coincided with regional climate cooling and moistening. Minimal fire activity was also observed during the Little Ice Age (0.7–0.25 ka BP). Fire frequencies increased during the interval from 1.7 to 0.7 ka BP and appears to be partly synchronous with climate warming during the Medieval Climate Anomaly. Regional reconstructions of long-term fire history show that recent fires are unprecedented during the late Holocene, with modern high biomass burning lying outside millennial and centennial variability of the last 3400 years.

Effects of dispersed multiwalled carbon nanotubes on the micro-explosion and combustion characteristics of 2-methylfuran – diesel mixture droplets

Isolated droplet combustion experiments have been carried out on neat diesel, a 15 vol% 2-methylfuran – 85 vol% diesel mixture (MF15), and nanofuels made from MF15 base fuel with addition of multiwalled carbon nanotubes (MWCNTs) at 25 ppm, 50 ppm, and 100 ppm concentrations (referred to as MF15C25, MF15C50, and MF15C100). Compared to MF15, the nanofuels displayed increased micro-explosion intensity and reduced micro-explosion occurrences, both effects being more pronounced at higher MWCNTs loadings. This behavior is attributed to the higher surface tension and viscosity of the nanofuels compared to that of MF15. The ignition delay decreased from 2.33 s to 1.71 s, the combustion rate constant increased from 0.82 mm2 s−1 to 1.01 mm2 s−1, and the combustion period reduced from 5.31 s to 4.54 s when going from pure MF15 to MF15C50. The improved combustion characteristics can be related to the superior thermal conductivity and large specific surface area of the dispersed MWCNTs in the nanofuels. The combustion characteristics of the nanofuel deteriorate at the highest MWCNTs dosing investigated here, possibly due to nanoparticle agglomeration. Overall, the present results suggest that dosing of MWCNTs at optimum levels improves the thermal efficiency and reduces the NOx emissions upon combustion of MF-diesel blends.

Quantifying the Influence of a Burn Event on Ammonia Concentrations Using a Machine-Learning Technique

Although combustion is considered a common source of ammonia (NH3) in the atmosphere, field measurements quantifying such emissions of NH3 are still lacking. In this study, online measurements of NH3 were performed by a cavity ring-down spectrometer, in the cold season at a rural site in Xianghe on the North China Plain. We found that the NH3 concentrations were mostly below 65 ppb during the study period. However, from 18 to 21 November 2017, a close burn event (~100 m) increased the NH3 concentrations to 145.6 ± 139.9 ppb. Using a machine-learning technique, we quantified that this burn event caused a significant increase in NH3 concentrations by 411%, compared with the scenario without the burn event. In addition, the ratio of ∆NH3/∆CO during the burn period was 0.016, which fell in the range of biomass burning. Future investigations are needed to evaluate the impacts of the NH3 combustion sources on air quality, ecosystems, and climate in the context of increasing burn events worldwide.

Exposure of Malaysian Children to Air Pollutants over the School Day

Children are sensitive to air pollution and spend long hours in and around their schools, so the school day has an important impact on their overall exposure. This study of Kuala Lumpur, Selangor and its surroundings assesses exposure to PM2.5 and NO2, from travel, play and study over a typical school day. Most Malaysian children in urban areas are driven to school, so they probably experience peak NO2 concentrations in the drop-off and pick-up zones. Cyclists are likely to receive the greatest school travel exposure during their commute, but typically, the largest cumulative exposure occurs in classrooms through the long school day. Indoor concentrations tend to be high, as classrooms are well ventilated with ambient air. Exposure to PM2.5 is relatively evenly spread across Selangor, but NO2 exposure tends to be higher in areas with a high population density and heavy traffic. Despite this, ambient PM2.5 may be more critical and exceed guidelines as it is a particular problem during periods of widespread biomass burning. A thoughtful adjustment to school approach roads, design of playgrounds and building layout and maintenance may help minimise exposure.

Research on Initial Prevention of Spontaneous Combustion in Coal Bunkers Based on Fire-Extinguishing and Fireproof Inerting.

Coal bunkers are relatively closed systems. Due to their own oxidation characteristics and the increase of temperature, spontaneous combustion will occur beyond the spontaneous combustion period. Moreover, spontaneous combustion of coal bunkers is a disaster caused by multifield coupling, so it is imperative to carry out inerting fire prevention and fire extinguishing. Based on this fact, combined with the actual situation in Huanghua Port, this paper establishes a two-dimensional geometric model of a coal bunker, selects CO2 as the inert gas sprayed in the coal bunker, determines the position of the inert gas port of the coal bunker hopper, and studies the influence of fireproof and fire-extinguishing inerting on coal bunker inerting. The results show that the arrangement of the inert gas port of the bunker hopper outside the bunker is more conducive to the diffusion of CO2 gas in the bunker. In about 35–41 days, the inerting temperature decreases slowly between 345 and 350 K. After 41 days, the maximum temperature of the coal bunker decreases rapidly and the spontaneous combustion of the coal bunker is completely controlled. Under the preset conditions, the best fire inerting time is 32.3 days after coal storage.

Characterization of particle sources and comparison of different particle metrics in an urban detached housing area, Finland

Particulate matter (PM) is emitted from various anthropogenic sources in urban areas affecting the local air quality. The aim of this study was to characterize the sources influencing air quality in detached house area in the Helsinki metropolitan area in Finland, and secondly, to explore the additional value of new particle physical properties to assess the impact of residential combustion on air quality. Measurements were conducted in an urban detached housing area between January and April 2019. Measured particle physical properties were particle number (PN), particle mass (PM1) and lung deposited surface area (LDSA) concentrations and number size distributions. In addition, particle chemical composition was measured using a soot particle aerosol mass spectrometer (SP-AMS; organic compounds, inorganic ions) and an aethalometer (black carbon (BC)). Concentrations of selected monosaccharide anhydrides and polycyclic aromatic hydrocarbons were analysed from the PM10 filter samples. The sources and characteristics of organic aerosol was investigated by applying positive matrix factorization to the mass spectra measured with the SP-AMS. Based on the variations in the measured particle physical parameters, chemical species and meteorology, the measurement period was divided into three sub periods dominated by urban background, wood burning and long-range transport (LRT) aerosols. Highest pollutant concentrations were measured during the wood burning and LRT periods. Wood burning increased the concentrations of all measured species, but the differences were most significant to levoglucosan, benzo(a)pyrene, BC and PM1 that had 12, 10, 6.4 and 3.6 times larger mean concentrations during the wood burning period compared to the urban background period, respectively. LRT affected significantly levoglucosan, PM1 and BC concentrations, since LRT pollutants partly originated from open biomass fires in Eastern Europe. The impact of local wood burning and LRT was quite small to particle number concentrations, whereas LDSA concentrations and size distributions were affected by traffic, wood combustion emissions and LRT. BC concentration correlated with the LDSA concentration during all periods suggesting a common origin. Particle number concentration was a good indicator of local combustion, especially traffic emissions, while the PM1 mass concentration together with secondary particle material was a good measure for the LRT pollutants. Benzo(a)pyrene was found to be a good indicator of local wood burning, but it was not detected in LRT biomass combustion particles.

Optimized neural network to predict the experimental minimum period of coal spontaneous combustion.

The harmful gases produced from coal spontaneous combustion (CSC) can cause the environmental pollution. Being able to predict the experimental minimum period of CSC (EMPCSC) is essential in controlling CSC and effectively reducing harmful gas emissions. To obtain high prediction accuracy, we used three optimization algorithms, namely the genetic algorithm (GA), ant colony algorithm (ACO), and particle swarm optimization algorithm (PSO), to optimize the backpropagation neural network (BPNN). R2, MSE, RMSE, and MAPE were used as evaluation indexes to determine the most accurate prediction model for EMPCSC. Data of 424 coal samples from 15 regions in China were analyzed, with 207 and 217 samples having a spontaneous combustion period of less than 40days (W) and more than 40days (V), respectively. The two groups were further distributed between low-temperature slow oxidation (W0 and V0) and low-temperature fast oxidation (W1 and V1). The results indicated that the prediction performance of the BPNN model optimized using PSO (PSO-BPNN) was better than that of the GA-BPNN and ACO-BPNN models. After optimization through PSO, the goodness of fit (R2) of groups W0, W1, V0, and V1 increased from 0.9180, 0.8746, 0.9987, and 0.9782 to 0.9857, 0.9639, 0.9997, and 0.9994, respectively. Therefore, the results can provide a theoretical reference for selecting the optimal neural network model to predict EMPCSC with high accuracy.

Modelling fire perimeter formation in the Canadian Rocky Mountains

Wildfires produce a mosaic of burned and unburned patches across varying temporal and spatial scales and provide a range of essential ecosystem services. Fire perimeters mark the separation between the burned and unburned matrix of a fire. Analysis of fire perimeters in the United States, Australia, and Alberta, have identified several key factors that influence the formation of a fire boundary, including fire environment variables, such as fuel, weather, and topographic conditions, as well as anthropogenic factors. We used matched case-control conditional logistic regression to assess the fire environment's influence on the formation of fire boundaries on the 2017 Verdant Creek Fire in the western Canadian Rocky Mountain region. Results indicated that fire boundary formation was strongly influenced by non-fuels, alpine and subalpine vegetation, wetland areas, and low and sparse shrub assemblages generally associated with avalanche paths. Fire cessation was more likely near waterways; however, the fire weather conditions that characterized most burning periods likely overrode other topographic influences. Fire cessation was most likely to occur one day following precipitation events when Vapour Pressure Deficit and Fire Weather Index values decreased. To explore the potential influence of spatial data resolution and fire mapping limitations on our results, we varied the distance between matched sample points selected on each side of the mapped fire perimeter during statistical modelling. Results demonstrated matched pairs of burned and unburned sample points were effective at representing discrete states when separated by at least 100 m and that insufficient or excessive separation between matched pairs confounds results, highlighting the importance of sensitivity analysis for determining the appropriate separation distance to represent burned and unburned states. We demonstrate a practical application of the model to predict spread potential, enabling rapid visual assessment of landscape locations most likely to limit fire spread.

Влияние температуры окружающей среды на инкубационный период и склонность угля к самовозгоранию

Crushing coal during mining significantly increases the contact area of combustible components with atmospheric oxygen. The heat released during coal oxidation can lead to an increase in the temperature of the coal accumulation and the appearance of places of spontaneous combustion. For the timely prevention of endogenous fires, it is required to know the incubation period of spontaneous combustion, which is necessary for the coal accumulation to reach the critical temperature. Based on this parameter, the category of coal propensity to spontaneous combustion is established, and measures are developed to reduce the endogenous fire hazard. The known method for estimating the incubation period does not sufficiently consider the influence of the environmental parameters on coal heating. The discrepancy between the calculated and actual duration is observed for coal at a negative temperature, for example, in the mines, and the open-casts in the permafrost areas, as well as in the warehouses in winter on a significantly large territory of Russia. Studies showed that a decrease in temperature significantly reduces the rate constant of oxygen sorption by the coal, and the release of heat in the coal accumulation. The process of spontaneous combustion of coal also slows down due to additional heat losses for the phase transition of water from solid to liquid state. For improving the accuracy of calculating the incubation period of spontaneous combustion of coal at negative temperatures, it is proposed to consider the specific heat of melting ice, and to determine the oxygen sorption rate constant at a constant temperature from –10 to –20 ° C. The influence of negative temperatures of coal accumulation increases the incubation period of spontaneous combustion of coal by 2–3 times allowing to reduce the cost of measures to prevent endogenous fires.

Comparisons of predictive ability of THAI in situ combustion process models with pre-defined fuel against that having fuel deposited based on Arrhenius kinetics parameters

Toe-to-heel air injection (THAI) is an in situ thermal-enhanced oil upgrading and recovery technology that makes use of a horizontal producer well for mobilised partially upgraded oil production to the surface. To design operation of the THAI process requires up-scaling lab-scale numerical model to field-scale reservoir numerical model. There are a number of up-scaling methods that were developed. However, these previous up-scaling methods only concentrated on the qualitative nature of the physicochemical processes. Furthermore, these methods have deficiencies ranging from assumption of 100% oxygen utilisation, failing to compare oil production rates for up-scaled reservoir models with and without fuel pre-defined, not reporting on the dynamics inside the reservoirs with and without fuel pre-defined, etc. As a result, this work provided in depth comparative studies of both the qualitative and quantitative physicochemical processes in numerical models containing Arrhenius-based coke deposition thermal cracking reaction (i.e. model A) and that having pre-defined fuel concentration (i.e. model F) as an initial parameter respectively. It is found that oil production started earlier in model A compared to in model F even though they have approximately similar trajectories. It is shown that by the end of the combustion period, oil recovery of 28.5% OOIP is achieved in model F which is greater than that in model A by an additional of 4.8% OOIP. It is found that the peak temperature, which indicates how healthy the combustion is at a single point only at different times, is generally considerably higher in model A than that in model F. It is further discovered that in some cases the combustion at all points might be stable and rigorous but in other cases the combustion might not be stable and rigorous at all points thereby implying that the peak temperature alone does not give the measure of the efficiency and spread of the combustion front. It is shown for the first time that pre-defining fuel concentration throughout the reservoir as is done in model F resulted in faster downward advancement and expansion of the combustion front compared to in the reservoir where the fuel is deposited based on the Arrhenius kinetics parameters (i.e. like in model A). It is also discovered that higher areal sweep of the reservoir is achieved in model F when compared to that achieved in model A. Overall, it then follows that higher volume of the reservoir of model F is combustion-swept, heat-affected, and oil-depleted compared to that in model A. These findings explain the reason why more oil is produced during the combustion period in model F than in model A. Conclusively, this first-of-a-kind study shows that pre-defining the fuel has no effect on the qualitative nature of the physicochemical processes, but has considerable influence on the quantitative parameters such as the rate of and cumulative oil production, peak temperature, areal and volumetric sweeps by the combustion zone, size of the oil-depleted zone, and size of the heat-affect zone. • Full analysis of predictive ability of THAI model F with pre-defined fuel is reported. • Model F predicted unrealistic high oil production rate & thus cumulative oil recovery. • Model F has faster downward-advancement & general expansion of the combustion fronts. • Higher reservoir volume is combustion-swept, heat-affected, & oil-depleted in model F. • Qualitative behaviours in model F are similar to those in the Arrhenius-based model A.

Seasonal patterns in rice and wheat residue burning and surface PM2.5 concentration in northern India

Rice-Wheat production system of the Indo-Gangetic Plain (IGP) in northern India generates large amounts of crop residues annually, substantial amount of which is burned in-situ. Due to this, people in this region and nearby cities are exposed to extremely high concentrations of atmospheric pollutants, especially in late autumn to winter. Multiple factors affect air quality, the main ones being pollutant emissions and meteorology. We generated a high-resolution (0.05° × 0.05°) multi-year (2012–2020) fine particular matter (PM 2.5 ) dataset of pollutant emissions from wheat and rice residue burning for the IGP by combining production data and satellite active fires from the Visible Infrared Imaging Radiometer Suite (VIIRS) 375-m product. We used surface PM 2.5 concentrations and meteorological data from Modern-Era Retrospective Analysis for Research and Applications version 2 (MERRA-2) atmospheric reanalysis to characterize the seasonal PM 2.5 concentrations and their relationships with anomalies in meteorological conditions. Results showed a much higher number of fires during from rice, with an interannual average of 79,385 total fires versus 33,096 from wheat. Emissions are higher during the rice harvest period: 406 Gg/year versus 245 Gg/year, respectively for rice and wheat. Emissions and PM 2.5 concentrations from rice harvest are higher than those of wheat as a consequence of a higher number of fire spots, emissions, and atmospheric conditions that prevent their dispersion. PM 2.5 concentrations are in addition strongly related to the amount of biomass burned and the number of fires and their intensity. In terms of meteorological anomalies, the planetary boundary layer height, wind speed and the surface thermal inversion strength have a stronger association with PM 2.5 concentration during the rice residue burning period. Conversely, PM 2.5 concentration and emissions anomalies during the wheat harvest shows a stronger correlation with factors associated with the amount of residues burned in the field. • Fire spots and PM 2.5 emissions from both rice and wheat residue burning concentrate over the west area of north India. • Maximum PM 2.5 emissions from rice (post-monsoon) residue burning are about twice those from wheat (pre-monsoon). • Post-monsoon PM 2.5 concentrations from rice residue burning are about three times higher than from wheat residue burning (pre-monsoon). • PM 2.5 shows a greater association with inversion strength and relative humidity during the rice harvest period.

Monitoring Persistent Coal Fire Using Landsat Time Series Data From 1986 to 2020

Coal fires pose great threats to valuable energy resources, the ecological environment, and human safety. They are one of the most persistent fires on the Earth, which can burn for an extremely long-term period from decades to hundreds or even thousands of years. Remote sensing detection of coal fires is of significance for mitigating coal fire hazards. Nevertheless, short-term or temporal discrete land surface temperature (LST) data have limited capability in characterizing the persistent coal fire. This study proposed a methodology to monitor persistent coal fires using long-term Landsat thermal images and further to analyze spatiotemporal dynamics of coal fires. A total of 1118 high-quality Landsat images (each image containing <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$446\times446$ </tex-math></inline-formula> pixels) spanning 35 years from 1986 to 2020 in the Wuda coalfield area (China) were processed to retrieve the LST. LST time series of each pixel was decomposed into the seasonal, trend, and remainder components. Coal fire areas were demarcated by using the range of the trend components. To trace the trend and change point of the LST time series, the Mann–Kendall test was applied to the trend components, and the Pettitt test was employed to the original time series vectors of those pixels located in the coal fire areas, respectively. The random sample consensus algorithm was utilized to identify the background temperature (inliers) and high temperature (outliers) and, thus, judge the coal fire burning period, and the symbolic aggregate approximation algorithm was used to evaluate the robustness of the judgment. The calibration was conducted according to the filed surveys, obtaining spatiotemporal 3-D coal fire dynamics. The proposed methodology was testified by comparisons with fieldwork and regional anomaly extractor algorithm, demonstrating good performance in comprehensive monitoring of persistent coal fires.

EFFECT OF INLET AIR TEMPERATURE ON COMBUSTION, PERFORMANCE AND EMISSIONS OF GASOLINE DIRECT INJECTION (GDI) ENGINE FUELLED BY LPG FUEL

In the present work, the direct-injection petrol engine (GDI) combustion, emissions and performance at different engine speeds (1500, 2000, 2500 and 3000 rpm) with a constant throttle position have been studied. The fuel considered in this work is liquid petroleum gas (LPG) and gasoline. The software adopted in all simulations by the AVL BOOST 2016. A Hyundai 2.0 liter, 16 valves and 4 cylinders engine with a compression ratio 17.5:1 is used. The effect of several inlet air temperatures (0, 10, 20, 30, 40 and 50 oC) on the engine performance, combustion and emissions are also studied. The results show that the increase in the inlet air temperature leading to increase the peak fire temperature, brake specific fuel consumption (BSFC) and nitrogen oxide (NOx). However, this process results in a reduction in the peak fire pressure, combustion period (duration), brake power and brake torque. The maximum fire temperature and maximum specific fuel consumption can be achieved when the engine speed is 3000 rpm and the inlet air temperature is 50 ºC.

Optimization of multiple-stage fuel injection and optical analysis of the combustion process in a heavy-duty diesel engine

The goals of this study were to optimize multiple-stage fuel injections and optically analyze the effects of multiple injections of fuel on the combustion process in a heavy-duty compressed ignition engine. The engine experiments consisted of pilot injection and post-injection experiments. The pilot injection quantities and timings were varied. The post-injection quantities and number of post injections were analyzed. Combustion images was obtained to calculate the flame temperature and soot density. The results revealed that premixed combustion by a single injection led to engine noise and vibration because of the long ignition delay. The optimal pilot injection strategy improved the engine noise, vibration, thermal efficiency, and nitrogen oxide emissions. However, a pilot injection induced diffusion combustion, and an increase in particulate matter emissions was inevitable. The optimized post-injection promoted the oxidization of incomplete combustion materials and provided a lower peak cylinder pressure, resulting in low nitrogen oxides and particulate matter emissions. The combustion images revealed that the pilot injection caused a moderate increase in flame temperature and high soot production. The post injection, however, effectively reduced the soot density during the late combustion period, resulting in a low soot density at the end of the observation period.

In-flame soot quantification of N-Hexadecane droplets using diffused back-illumination extinction imaging

To gain insights into spray combustion, the combustion characteristics of single droplets need be investigate. In this study, soot production measurements were performed on single droplet of N-Hexadecane using the two optical techniques of natural flame luminosity imaging and diffused back-illumination extinction imaging (DBIEI). These measurements were performed in a suspended single-droplet combustion setup under ambient temperature and atmosphere. The experimental results from both methods are positively correlated with the combustion process. The images captured using the two methods clearly show the premixed and non-premixed combustion periods. The ratio of soot radiation to flame radiation is nearly constant in non-premixed combustion. The DBIEI results for the natural soot luminosity indicate a shorter distance than the attenuated soot intensity along the vertical direction. The results demonstrate that DBIEI technique is capable of quantitatively measuring the instantaneous soot formation during single droplet combustion.

Analysis of Air Flow, Air and Fuel Induction for Internal Combustion Engine

In an internal combustion engine, performance, efficiency and emission formation depends on the formation of air-fuel mixture inside the engine cylinder. The fluid flow dynamics plays an important role for air-fuel mixture preparation to obtain the better engine combustion, performance and efficiency. This review article discuss the rotating flow (swirl and tumble) in premixed spark-ignition engine and its effect on turbulence generation and flame propagation. Rotating flow can substantially increase turbulence intensity for the duration of the combustion period. This review paper discusses the in-cylinder swirl and tumble flow that affects air induction during the combustion process in internal combustion engine. Alternatively, this study using computer simulation (Computational Fluid Dynamic, CFD) which offer the opportunity to carry out repetitive parameter studies. An integration-type flowmeter (IFM) also has been used which consists of ultrasonic flowmeter, that integrates the flowrate during the intake process, gives accurate measurements regardless of sampling time and frequency. Research parameter in this study was swirl and tumble that represents the fluid flow behavior occurred inside combustion chamber. Fuel injection and air mass also were the important parameters that have been discussed about in air induction process. The results obtain from the numerical analysis can be employed to examine the homogeneity of air-fuel mixture structure for better combustion process and engine performance.

Rapid Contrastive Experimental Study on the Adiabatic Spontaneous Combustion Period of Loose Lignite.

The adiabatic spontaneous combustion period of coal is an important index for the macroscopic characterization of coal spontaneous combustion, and it is affected by many internal and external factors. There are several methods to study it, but there are various shortcomings to these methods. Some require too much time, while others have too many interfering factors. To quickly obtain the accurate adiabatic spontaneous combustion period of coal, a rapid contrastive experimental method was designed. In this method, the coal samples of the experimental and control groups were the same, and air and nitrogen were used as control atmospheres. A theoretical calculation method for the adiabatic spontaneous combustion period based on this method is proposed. The experimental results showed that during the temperature-programmed coal spontaneous combustion experiment, the increase in the coal temperature was due to physical and chemical heating. Physical heating is the heating effect of the temperature-programmed furnace body and the heated gas on the coal sample. Chemical heating includes oxidative exothermic heating promoted by physical and adiabatic oxidation heating. The adiabatic oxidative heat release can be determined by the oxidation heat release in the air atmosphere minus the oxidation heat release corresponding to the coal sample temperature in the nitrogen environment at the same period. The adiabatic spontaneous combustion period of coal can be calculated from the adiabatic oxidation heat release. Our results provide a rapid contrastive experimental method to quickly obtain the accurate adiabatic spontaneous combustion period of coal.

Rheosorbilact in complex intensive therapy of burn toxemia

Background. Thermal injuries primarily cause coagulation necrosis and cell death with vascular thrombosis in the areas of the deepest lesion.Objective. To study the effectiveness of rheosorbilact in infusion therapy during the period of burn toxemia.Materials and Methods. The results of monitoring the daily volume of the injected fluid, infusion therapy and renal excretory activity of 25 patients admitted to the Department of Combustiology of Republican Research Center of Emergency Medicine due to burn injury were studied.Results. The average daily volume of infusion therapy in group 1, FI – 119.4 ± 38.4 units at the age of 27.3 ± 5.6 years, was 76 ± 7 ml/kg per day, in group 2 (50.7 ± 7.1 years), FI – 92.5 ± 20.8 units, the introduction of 64 ± 9 ml/kg was effective, in group 3 (71.3 ± 7.0 years), FI – 86.7 ± 12.8 units, the introduction of an average of 48 ± 11 ml/kg per day was sufficient. In the nonlinear nature of changes in intravenous infusion, 4–5-day periods can be noted, probably due to the current factors that determined the need to increase or decrease infusion therapy. The introduction of rheosorbilact in a volume of 10 ml/kg per day increased the hourly renal excretory activity in all patients during the period of toxemia. The diuretic effect was more pronounced in patients of group 1, which corresponded to a greater volume of water load and the severity of burn injury.Conclusions. The introduction of rheosorbilact in a volume of 10 ml/kg per day increased the hourly renal excretory activity in all patients during the period of toxemia.

Assessment of Smoke Pollution Caused by Wildfires in the Baikal Region (Russia)

Climate change has increased the prevalence of wildfires, resulting in longer fire seasons and larger geographic area burned. The aim of this work was to assess the air pollution and health risk to the population caused during exposure to smoke in fire season. The study design included: an analysis of long-term air pollution to determine background levels; an analysis of short-term (&lt;24 h) and subchronic (10–14 days) concentrations during wildfires; and an assessment of the health risk in the industrial center of the Baikal region (Russia). In Irkutsk, at a distance of 2000 km from the fire focal points, the maximum short-term concentrations of pollution were noted during the smoke period, when the average CO level increased 2.4 times, and PM1 increased 1.4 times relative to the background levels in August 2021. In Bratsk, located near the fires, the increases in short-term concentrations were: CO—21.0; SO2—13.0; formaldehyde—12.0; TPM—4.4 times. The hazard indices of respiratory and coronary diseases in the burning period exceeded the acceptable level. Acute reactions to smoke can be expected in 30% of the exposed population near fires and 11% in remote areas (Bratsk). The results obtained from the remote sensing of atmospheric smoke can be used to urgently resolve the issue of organizing medical assistance or evacuating the population groups most sensitive to the effects of smoke in fire season.

Air quality impact of slash pile burns: Simulated geo-spatial impact assessment for Washington State

In the Western U.S., the prescribed burning of woody biomass in forests, mainly harvest slash, is the prevailing practice for in-woods fuel reduction and wildfire mitigation. Though these prescribed burns play an essential role in mitigating the wildfire risks, the resultant emission is a major air pollutants source that adversely affects air quality, negatively impacting human health. With an increased need for fire hazard reduction thinning, coupled with shrinking regional demand for lower quality biomass (pulpwood, hog-fuel, etc.), the volumes of unused biomass left on the forest floor as ‘waste’ will continue to grow. Reducing prescribed burns by utilizing this ‘waste’ biomass for alternate bio-based solutions (like bio-energy or bio-char) will enhance the economic feasibility of much-needed thinning operations and reduce uncontrolled emissions and related environmental and local health impacts.In this study, we simulate the increase in air pollutants due to additional prescribed fires in the Southwestern part of Washington State. Using the ‘BlueSky smoke modeling system,’ the study estimated the emissions associated with burning additional 726,000 dry t of residual biomass, which corresponds to a 30% increment from 2011. The burn was simulated over 29 days of the fall quarter and subsequently incorporated into the AIRPACT pollution transportation modeling system using the 2011 air quality and meteorological data as the baseline. The results showed that the ambient PM2.5 concentrations, due to the simulated pile burns, exceeded EPA's air quality standards on multiple days and in various locations across the Western part of the state, with two days reaching “very unhealthy” levels and one day reaching “hazardous” levels. By layering the census data on top of the pollution concentration data, the model estimated that, over the 29-day burn period, approximately 440,000 additional human days would be affected by higher than the EPA air-quality standards for ambient PM2.5 levels.