Amount Of Carbon Research Articles

Soil carbon mineralization decreased in desert steppe by light grazing but not fencing management

Fencing off grassland soils emits massive amounts of carbon into the atmosphere. Whether grazing management in desert steppes with fragile ecosystems can mitigate this trend remains highly uncertain. Here, we examined how soil carbon mineralization, as well as its underlying mechanisms, varied with grazing intensity by sheep in a long-term (17 − year) experiment in the desert steppe. Carbon mineralization decreased by 15 % − 55 % under different grazing intensities compared to fencing controls. Soil organic carbon (SOC) maintained high levels under light grazing, whereas it decreased with increasing grazing intensity. Reductions in plant carbon and absolute microbial abundance due to grazing, coupled with changes in soil carbon quality and the environment, drove the reduction in carbon mineralization. We suggest that mechanisms of carbon mineralization can be integrated into predictive modelling efforts to better understand the impact of grazing on carbon fluxes in ecologically fragile, but globally important, arid and semi-arid grasslands.

Strengthening Polymer Concrete with Carbon and Basalt Fibres

To date, composite materials, such as polymer concrete, have found wide application in various industries due to their unique properties combining high strength, resistance to aggressive media and durability. Improving the performance characteristics of polymer concrete is an important task aimed at expanding the areas of its application. One of the promising methods of increasing the strength of this material is the use of various fillers. In this paper, the effect of fillers, based on carbon and basalt fibres, on the mechanical properties of polymer concrete was investigated. The polymer concrete was made of the following components: rubble stone, sand, quartz flour and polyester resin. During the experimental work, the amount of carbon and basalt fibres in the polymer concrete mixture varied from 0 to 6%. Bending and compressive strength tests showed that the addition of carbon and basalt fibres increased these properties. The highest bending and compressive strengths were achieved when carbon fibre contents were up to 1.5%, while basalt fibres provided the highest strengths in the case of around 2%. These results confirmed that carbon fibres had a higher efficiency in strengthening polymer concrete compared to that of basalt fibres. This could be explained by the fact that carbon fibres had a higher tensile strength and modulus of elasticity, which allowed them to better redistribute loads within the composite material. The fibre length for carbon fibre, which gave the maximum increase in properties, was 10–15 mm. For basalt fibre, the maximum bending strength was reached at 20 mm and compressive strength at 10 mm. Increasing the content of carbon fibre above 2% and basalt fibre above 1.5% did not give further increase in mechanical properties. In conclusion, it could be stated that the use of carbon fibres as fillers offered significant advantages in strengthening polymer concrete, opening up opportunities for its use in more demanding conditions and in a wider range of industrial applications.

Influence of Na2CO3 on the activation degree and microstructure of coal gasification coarse slag

ABSTRACT Silicon in coal gasification coarse slag (CGCS) accounts for more than 40%. CGCS can be developed into an inorganic silicon source to improve its utilization value. Alkali activation can increase extraction rate of silicon. In this study, the influence of Na2CO3 on the activation degree and microstructure of CGCS was investigated. The activation mechanism was discussed based on IR, XRD, SEM, and EDS data. The results showed that the dosage of Na2CO3 was positively correlated with SiO2/Al2O3 in CGCS, which is generally 0.8 ~ 1.3 times of CGCS. The activation temperature of CGCS was 800°C ~ 850°C. A small amount of residual carbon could slightly reduce the activation temperature. The alkali activation process involved depolymerizing the polymer structure into an oligomer, whereby the crystalline structure was transformed into an amorphous structure. Moreover, Q4 structure in CGCS could be more easily activated than Q3 or Q2 structure. The activation reaction was carried out under gas-liquid-solid three-phase conditions. The diffusion effect of CO2 gas could be fully utilized in the activation process to ensure the melting of heteroatoms and the formation of defects, which prevented the emergence of crystalline substances. This research provides a solid theoretical foundation for low-cost and high-quality extraction of silicon from CGCS.

From Bulk to Nano: Formation, Features, and Functions of Nano-Black Carbon in Biogeochemical Processes.

Globally increasing wildfires and widespread applications of biochar have led to a growing amount of black carbon (BC) entering terrestrial ecosystems. The significance of BC in carbon sequestration, environmental remediation, and the agricultural industry has long been recognized. However, the formation, features, and environmental functions of nanosized BC, which is one of the most active fractions in the BC continuum during global climate change, are poorly understood. This review highlights the formation, surface reactivity (sorption, redox, and heteroaggregation), biotic, and abiotic transformations of nano-BC, and its major differences compared to other fractions of BC and engineered carbon nanomaterials. Potential applications of nano-BC including suspending agent, soil amendment, and nanofertilizer are elucidated based on its unique properties and functions. Future studies are suggested to develop more reliable detection techniques to provide multidimensional information on nano-BC in environmental samples, explore the critical role of nano-BC in promoting soil and planetary health from a one health perspective, and extend the multifield applications of nano-BC with a lower environmental footprint but higher efficiency.

Effects of land reclamation on peatland carbon stability in Sanjiang Plain (Northeast China) over the last century

Peatlands store vast amounts of soil carbon and the stability of this carbon pool plays a crucial role in the carbon dynamics under global change. In the Sanjiang Plain, one of the important peatlands distributed region in China, peatlands were seriously affected by the regional land reclamation during the last century. While, there is a scarcity of data evaluating the impact of land reclamation on peatland carbon stability. Here, based on 210Pb dating of the Shenjiadian (SJD) peatland, we reconstructed historical variations in peatland carbon stability and assessed its response on regional land reclamation over the last century in the Sanjiang Plain. The results showed that the highest aromatic content (25.2 ± 0.7 %) and the lowest carbohydrate content (34.7 ± 2.5 %) occurred between 1950 and 1980, coinciding with the period of extensive second land reclamation in the Sanjiang Plain. The increase in regional human activities led to greater accumulation of pyrogenic carbon in the peatland, enhancing carbon stability in the 1950 s. However, as farmland area continued to grow in the 1960 s, local fires caused by agricultural activities led to more frequent peat fires, promoting the accumulation of herbaceous litter in the peatland, which decreased the stability of the peatland carbon pool but increased carbon accumulation rates. With the proportion of shrub litter increasing and regional land reclamation weakening after 1980, the accumulation of shrub litters has increased both carbon stability and carbon accumulation rates in the studied peatland, particularly after 2000.

Performance optimization design of high ductility concrete rapid repair material incorporating coal gangue aggregate

In order to solve the problem of efficient and effective repair after brittle cracking of concrete on road and bridge deck pavements, and to consider the resource utilization of coal gangue solid waste, the river sand was replaced by coal gangue and a high ductile concrete rapid repair material (HDCRRM) was prepared through performance optimization design. First, the fluidity and compressive strength of materials mixed with different amounts of sulfoaluminate cement (SAC), fly ash, lithium carbonate, calcium hydroxide, calcium formate, sand-binder ratio, water-binder ratio and polycarboxylate superplasticizer were studied, so as to determine the preferred benchmark mix proportion. Then, the replacement rate of coal gangue was optimized to develop HDCRRM. Test results show that the reduction of SAC cement and the increase of fly ash content can weaken the compressive strength of material. The rational design content of lithium carbonate, calcium hydroxide, calcium formate, sand-binder ratio, water-binder ratio and polycarboxylate superplasticizer all can improve the fluidity and compressive strength of the materials within a certain range. When the replacement rate of coal gangue aggregate increases, the tensile elastic modulus and ultimate tensile strength of HDCRRM material decrease, while the ultimate tensile strain increases. When the replacement rate of coal gangue aggregate is 100 %, the compressive strength of HDCRRM is 40.5 MPa, the ultimate tensile strain is 2.83 %, and the average crack width is 50.27μm. The early compressive strength of HDCRRM is mainly provided by a large amount of ettringite and C-S-H gel.

Subducted carbon weakens the forearc mantle wedge in a warm subduction zone

Subducting oceanic plates carry large amounts of carbon into the Earth’s interior. The subducted carbon is mobilized by fluid and encounters ultramafic rocks in the mantle wedge, resulting in changes to the mineral assemblage and mechanical properties of the mantle. Here, we use thermodynamic modeling of interactions between carbon-bearing multi-component fluids and mantle rocks to investigate the down-dip variation in mineral assemblage in the forearc mantle along subduction megathrusts. We found that fluids rich in aqueous carbon are preferentially generated in a warm subduction zone (e.g., Nankai, SW Japan), causing a change in mineral assemblage from serpentine-rich at the mantle wedge corner to talc + carbonate-rich at greater depths. The transition caused by the infiltration of aqueous carbon may influence the depth of the boundary between the seismogenic and aseismic zones, and the down-dip limit of episodic tremor and slip.

Redox conditions influence the chemical composition of iron-associated organic carbon in boreal lake sediments: A synchrotron-based NEXAFS study

The global carbon and iron cycles are intimately linked as redox-sensitive iron oxides readily bind organic carbon in a variety of environmental settings, including marine and lacustrine sediments. While these iron-organic carbon complexes sequester vast quantities of organic carbon, the composition of the organic matter within them remains unknown for lacustrine environments. Here we present C K1s and Fe L3,2 edge Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra of surface sediments and authigenic iron complexes from adjacent basins of a pristine boreal lake located in Québec, Canada, with contrasting oxygen exposure regimes. We demonstrate differences in organic carbon speciation in sediments from both basins, as well as co-localization of organic carbon and iron on a sub-micron scale in 100 nm thick samples. Differences in redox cycling across these two basins allow for a direct comparison of the effect of oscillating redox conditions on the composition of organic carbon sequestered by iron. Our results suggest that reactive organic molecules, which may be polysaccharides, were found preferentially associated with iron in the perennially oxic sediments compared to more phenol rich organics in the seasonally anoxic sediments, highlighting the importance of iron oxides in the protection and preservation of labile organic compounds. Traces of aliphatic carbon were observed in sediments from the anoxic basin, alongside carboxyl and aromatic functionalities. This carboxyl-rich aliphatic material could possibly interact with the sediment mineral matrix either through a ligand exchange mechanism between the mineral phases and the carboxyl functionalities, or via non-specific hydrophobic interactions involving the aliphatic moieties. Finally, our work also shows that OC:Fe ratios should be used with caution when inferring a binding mechanism between OC and iron oxides.

Mechanism and kinetics of ultrasound-enhanced CaCO3 precipitation for indium enrichment in zinc oxide dust leaching solution

In this study, ultrasound-enhanced calcium carbonate precipitation was used to enrich indium in zinc oxide dust leachate, and the effects of precipitation endpoint pH and ultrasound power on the indium precipitation behaviour were investigated, and the optimal conditions of ultrasound-enhanced precipitation were obtained to be the precipitation endpoint pH of 4.0 and the ultrasound power of 200 W. The precipitation rate of indium under these conditions was 99.79 %. At the same time, the effects of ultrasonication and conventional stirring on the indium precipitation kinetics were compared, which proved that ultrasound can shorten the time for precipitation to reach equilibrium and reduce the amount of calcium carbonate used, and the theory of ultrasonication activation energy was put forward. The activation energy of ultrasonication was Eu-a = 2.63 KJ/mol, and that of conventional precipitation was 9.78KJ/mol, which proved that ultrasonication could reduce the activation energy of the precipitation reaction, and promote the rapid precipitation reaction. The kinetic model of ultrasound-enhanced indium precipitation is lnC0-lnCt = exp(0.11339–318.54/W).t + A. In addition, the mechanism of ultrasound-enhanced calcium carbonate precipitation of indium was revealed by XRD, SEM-EDS, XPS and TEM analyses of the precipitated residue, it was demonstrated that ultrasound can inhibit the precipitation of zinc, and the ZnCO3 phase was found in the ultrasonically precipitated residue. This study provides a new idea for indium enrichment, and the future focus will be on the scale-up of the ultrasound-enhanced precipitation device.

Development of CuO/ZnO/Al2O3-hydrotalcite −based catalysts for middle temperature water gas shift reaction: Impact of calcination temperature and residual carbonates

A series of Cu/ZnO/Al2O3 catalysts are synthesized using a reverse co-precipitation method and subjected to calcination at different temperatures ranging from 300 to 650 °C. Characterization of the resulting powders is carried out through ICP, N2-physisorption, XRD, TGA, H2-TPR, N2O chemisorption and SEM techniques. Subsequently, the catalytic performance of the final samples is assessed in the medium-temperature water gas shift reaction across a broad temperature range from 200 to 330 °C. The precursor predominantly featured a hydrotalcite-like structure, undergoing decomposition through three main stages by losing structural H2O and CO2 molecules. All catalysts demonstrated stable performance without by-products during accelerated aging under reaction conditions. The results revealed that the partial elimination of carbonate ions at 300 °C resulted in easily reducible and consequently less thermally stable active sites. For calcined samples at 450 °C and 550 °C the thermal sintering played a pivotal role, leading the less copper surface area and subsequently higher CO slip values. In the case of the calcined sample at 650 °C, despite larger CuO and ZnO crystals, a trade-off between the emission of high-temperature carbonates and thermal sintering led to acceptable activity and thermal stability. Ultimately, the highest Cu surface are of 222 m2gr cat −1 along with the lowest amount of CO slip are observed for calcined sample at 350 °C, attributed to an optimal amount of carbonate, resulting in the superior catalytic performance. This effective balance between thermal sintering and the amount of residual carbonates yielded a final catalyst with outstanding activity and stable performance.

Factors controlling peat soil thickness and carbon storage in temperate peatlands based on UAV high-resolution remote sensing

Peatlands store a large amount of carbon. However, peatlands are complex ecosystems, and acquiring reliable estimates of how much carbon is stored underneath the Earth’s surface is inherently challenging, even at small scales. Here, we aim to establish links between the above- and below-ground factors that control soil carbon status, identify the key environmental variables associated with carbon storage, as well as to explore the potential for using Unmanned Aerial Vehicle (UAV) remote sensing for spatial mapping of peatlands. We combine UAVs equipped with Red-Green-Blue (RGB), multispectral, thermal infrared, and light detection and ranging (LiDAR) sensors with ground-penetrating radar (GPR) technology and traditional field surveys to provide a comprehensive, 3-dimensional mapping of a peatland hillslope-floodplain landscape in the Belgian Hautes Fagnes. Our results indicate that both peat thickness and soil organic carbon (SOC) stock (top 1 m) are spatially heterogeneous and that the contributions from the surface topography to peat thickness and SOC stock varied from micro- to macro-scales. Peat thickness was more strongly controlled by macro-topography (R2 = 0.46) than SOC stock, which was more influenced by micro-topography (R2 = 0.21). Current vegetation had little predictive power for explaining their spatial variability. Additionally, the UAV data provided accurate estimates of both peat thickness and SOC stock, with RMSE and R2 values of 0.16 m and 0.85 for the peat thickness, and 59.25 t/ha and 0.85 for the SOC stock. However, similar performance can already be achieved by using only topographical data from the LiDAR sensor (for peat thickness) and a combination of peat thickness and topography (for SOC stock) as predictor variables. Our study bridges the gap between surface observations and the hidden carbon reservoir below. This not only allows us to improve our ability to assess the spatial distribution of SOC stocks, but also contributes to our understanding of the environmental factors associated with SOC storage in these highly heterogeneous landscapes, providing insights for environmental science and climate projections.

Composted maize straw under fungi inoculation reduces soil N2O emissions and mitigates the microbial N limitation in a wheat upland

Enhancement of microbial assimilation of inorganic nitrogen (N) by straw addition is believed to be an effective pathway to improve farmland N cycling. However, the effectiveness of differently pretreated straws on soil N2O emissions and soil N-acquiring enzyme activities remains unclear. In this study, a pot experiment with four treatments (I, no addition, CK; II, respective addition of maize straw, S; III, composted maize straw under no fungi inoculation, SC; and IV, composted maize straw under fungi inoculation, SCPA) at the same quantity of carbon (C) input was conducted under the same amount of inorganic N fertilization. Results showed that the seasonal cumulative N2O emissions following the SCPA treatment were the lowest at 4.03 kg N ha−1, representing a significant reduction of 19 % compared with the CK treatment. The S and SC treatments had no significant effects on N2O emissions. The decrease of soil N2O emissions following the SCPA treatment was mainly attributed to the increase of microbial N assimilation and the increased abundance of functional genes related to N2O reductase. The SCPA treatment significantly decreased soil alkaline phosphatase (ALP) activity and increased leucine aminopeptidase (LAP) activity at the basal fertilization, while increased soil ALP and LAP activity, decreased soil N-Acetyl-β-D-Glucosidase (NAG) activity at harvest. Compared with the CK treatment, the S, SC, and SCPA treatment significantly increased soil β-glucosidase (β-GC) activity at harvest. The decrease in the (NAG+LAP)/ALP ratio following the SCPA treatment indicated that the composted maize straw under fungi inoculation alleviated microbial N limitation at harvest. Moreover, PICRUSt analysis also suggested that the SCPA treatment increased the abundance of bacterial genes associated with N assimilation and N2O reduction, whereas the S and SC treatment did not significantly affect the abundance of N2O reduction genes compared with the CK treatment. Our results suggest that the composted maize straw under fungi inoculation would reduce the risk of N2O emissions and effectively mitigate the microbial N limitation in dryland wheat system.

An integrated convolutional neural network prediction framework for in situ shale oil content based on conventional logging data

The quantification of total organic carbon (TOC) and the free hydrocarbon content (S 1 ) is crucial for evaluating the shale oil generation and bearing properties of source rocks. This study aimed to enhance the accuracy of TOC and S 1 quantification in shale oil evaluations. The scope encompassed the development of a novel deep learning framework to overcome the limitations of traditional physical and machine learning or deep learning methods. This paper proposes an integrated swarm optimization algorithm–convolutional neural network/machine learning framework. This framework uses a swarm optimization algorithm for the hyperparameter optimization of a convolutional neural network or machine learning framework, utilizing experimental data from core samples preserved in liquid nitrogen alongside well logging data. The application of the proposed framework to the H11 well in the Subei Basin, China, using 110 core samples, demonstrated a superior performance. The results validate the framework's effectiveness in predicting the TOC and S 1 contents at various depths. The proposed framework stands out for its convenient methodology, wide application range and high precision in prediction. These attributes contribute significantly to the field of petroleum engineering and development, offering a novel approach that promises to enhance both the efficiency and accuracy of well logging evaluation.

Valorisation of bamboo stalk waste: eco-friendly synthesis and characterisation of activated carbon monolith

ABSTRACT In contemporary waste management, the escalating volumes of bamboo stalk waste present a pressing environmental challenge, necessitating innovative and sustainable solutions. This research examined the properties of activated carbon monolith (ACM) derived from bamboo stalk (BS) using a facile method. Polystyrene resin and KOH were employed as an eco-binder and activator in the monolith synthesis, respectively. Analytical methods were employed to characterise the mechanical, morphological, elemental, and textual profiles of the monolith obtained. The study's results indicated the creation of a monolith characterised by a rough, amorphous shape firmly secured by the binder. It revealed a BET surface area measuring 265 m2/g and a pore diameter of 2.8 nm. The monolith displayed various irregular void pores, forming a mesoporous morphological network, along with sporadically distributed slivery-white dot-like particles on its heterogeneous surface. EDX analysis also revealed the BS-ACM is largely composed of carbon (77%), potassium (11%), oxygen (8%), and trace amounts of aluminium, gold, iron, and plutonium. The compressive strength test indicated a peak force of 21,536 N before any significant signs of appreciable deformation were observed, with the subsequent estimation of Young's modulus at 8.34 MPa. Beyond advancing bamboo waste valorisation, the research aligns with circular economy principles and sustainable practices, presenting a promising pathway for developing eco-friendly materials and contributing to a more sustainable and resource-efficient future.

Assessment of Woody Species Biodiversity and Carbon Stock Potentials in the Arboretum of National School of Water and Forests of Mbalmayo, Center Region of Cameroon

Assessing forest biodiversity is crucial for supporting sustainable forest planning. We investigated the potential for biodiversity and carbon sequestration in both artificial and natural forests of the arboretum of the National School of Water and Forests (ENEF) of Mbalmayo. A floristic inventory was carried out in 72 plots measuring 25m x 25m in the artificial forest covering an area of 4.5ha, and in a quadrat measuring 250m x 180m in the natural forest of the arboretum. Carbon stocks were determined by the non-destructive method using allometric equations. The results of the woody biodiversity inventories identified 77 species belonging to 69 genera and 33 families. This species richness varied from 69 species in the natural forest to 58 species in the artificial forest. Tree density was slightly higher in the artificial forest (616 ±339 ind/ha) than in the natural forest (312 ±176 ind/ha), without being significantly different. Basal area was constant in both types of forest studied, with an average of 55.97 ±36.28 m2/ha in the artificial forest and 58.33 ±19.42 m2/ha in the natural forest. The greatest quantity of sequestered carbon was found in the natural forest with 432±146.49 tC/ha compared with 400.69±328.37 tC/ha in the artificial forest. Nevertheless, these rates were not significantly different according to the ANOVA test. Given the importance of this massif in carbon sequestration and the needs of local populations, ENEF should support these populations in agroforestry practices and in the domestication of priority tree species.

Development of a Computer Model for Determining the Composite Fuel Composition and Quality

This article develops a computer model for determining the composition and quality of composite fuel. Coal-water fuel was considered as the object of study. Empirical formulas were used to determine the calorific value of composite fuel, and their results were compared with experimental results. Using the Python program, a model was created to determine the composition and calorific value of coal-water fuel using the Mendeleev and Knievel formulas. According to the created computer model, it is shown that the calorific value of coal-water fuel depends to a greater extent on carbon, hydrogen and oxygen than on other components in its composition. The decrease in the amount of carbon and hydrogen in coal-water fuel led to a decrease in the heat of combustion of the fuel. It is also shown that oxygen and heat of combustion are inversely proportional.

A Case Study on Biomass Assessment in a Semi-Arid Olive Rainfed System in Morocco

Thanks to its potential life span of hundreds of years, olive can develop great biomass and sequester large amounts of carbon (C). It may therefore play a critical role in reducing atmospheric C and improving farmer livelihoods by providing additional revenue from C credits. Predicting olive’s impacts on C cycling relies on allometric models. In our specific conditions, such models reliably predicted biomass accumulation with a minimum of three dendrometric measurements: tree age, height, and diameter at 10 cm.

A Novel Synthesis Method of Dumbbell-like (Gd1-xTbx)2O(CO3)2·H2O Phosphor for Latent Fingerprint.

A novel method for synthesizing dumbbell-shaped (Gd1-xTbx)2O(CO3)2·H2O (GOC:xTb3+) phosphors using sodium carbonate was investigated. An amount of 1 mmol of stable fluorescent powder can be widely prepared using 3-11 mmol of Na2CO3 at a pH value of 8.5-10.5 in the reaction solution. The optimal reaction conditions for the phosphors were determined to be 7 mmol for the amount of sodium carbonate and a pH of 9.5 in the solution. Mapping analysis of the elements confirmed uniform distribution of Gd3+ and Tb3+ elements in GOC:xTb3+. The analysis of fluorescence intensity shows that an optimal excitation wavelength of 273 nm is observed when the concentration of Tb3+ is between 0.005 and 0.3. The highest emission intensity was observed for GOC:0.05Tb3+ with a 57.5% maximum quantum efficiency. The chromaticity coordinates show that the color of GOC:Tb3+ is stable and suitable for fluorescence recognition. Latent fingerprint visualization reveals distinctive features like whorls, hooks, and bifurcations. Therefore, the sodium carbonate method offers an effective alternative to traditional urea chemical reaction conditions for preparing GOC:Tb3+.

Mathematical Model of Gasification of Solid Fuel

This paper presents an innovative mathematical model of solid fuel gasification, which is not described in the available literature. The calculation of the components of the heterogeneous phase (including both solid and gaseous phases) as well as the calculation of the homogeneous phase (only gaseous components) is based on the balance of the total amounts of carbon, oxygen, hydrogen, and nitrogen entering the reactor space. Additionally, this paper introduces a new method for calculating the composition of the gaseous phase, based on reducing the heterogeneous mixture (composed of solid and gaseous phases) to a homogeneous gaseous phase. This approach to calculating the gaseous phase composition in the solid fuel gasification process has not been found by the authors in the cited literature. This paper also presents a model for calculating the heterogeneous and gaseous phases using the number of moles that participate in the assumed chemical reactions of the solid fuel gasification process. This approach to calculating the composition of the heterogeneous and gaseous phases of the solid fuel gasification process is also not represented in the cited literature. For comparison with the literature data, municipal solid waste (MSW) and cashew nut shell (Cashew Shell Char (CNSC)) were used as fuels in the calculation of gasification composition. The results of the calculation of the gaseous phase composition using the model presented in the paper show good agreement with the data from the literature. The calculation of the composition of the heterogeneous mixture during the steam gasification of MSW (α = 0.4) shows the presence of a solid phase (carbon) up to approximately 735 °C. At that temperature, the synthetic gas contains only gaseous components: CO = 33.10%, H2 = 52.70%, CH4 = 2.54%, CO2 = 4.97, H2O = 5.93% and N2 = 0.76%. Increasing the temperature above 735 °C eliminates the solid phase from the equilibrium mixture. The literature data on solid fuel gasification generally do not consider the proportion of the solid phase (carbon) in the equilibrium mixture. To satisfy the material balance at the input and output of the gasification reactor, it is necessary to determine the proportion of the solid phase (carbon) in the equilibrium mixture. Since the proportion of the solid phase (carbon) in the heterogeneous equilibrium mixture can only be determined through measurement, the development and application of a mathematical model in engineering practice is of great importance, so this developed model can be considered a useful tool for simulating the influence of process parameters on gas characteristics.

Microbial Diversity in Cold Desert Ecosystem: A Review and Bibliometric Analysis

Cold deserts play a unique and crucial role in the environment. Glaciers in these regions store significant amounts of freshwater, essential for ecosystems, while permafrost sequesters large quantities of carbon, preventing the release of greenhouse gases. These areas host diverse species, contributing to global biodiversity and a variety of extremophile life forms. The microbial communities in cold deserts—comprising bacteria, cyanobacteria, archaebacteria, fungi, and lichens—have adapted to harsh conditions. They maintain ecological balance by forming symbiotic interactions with plants, enhancing soil fertility, and boosting crop yields. Additionally, several microorganisms are involved in bioremediation processes. Microorganisms found in cold desert environments also serve as valuable biosignatures for detecting life, significantly advancing the field of astrobiology. This review explores the microbial diversity of cold deserts through bibliometric analysis using VOSviewer software. The software identified 47 countries engaged in cold desert research, with the United States leading in the number of publications. A total of 2009 keywords were analyzed, with "bacteria (microorganisms)" being the most common. This review encompasses studies on the microbial diversity of cold deserts and their applications, highlighting crucial directions for future research