Moisture Evaporation Research Articles

Thermal Decomposition and Kinetic Analysis of Amazonian Woods: A Comparative Study of Goupia glabra and Manilkara huberi

This study presents a detailed analysis of the thermal degradation and kinetic behavior of two Amazonian wood species, Goupia glabra (cupiúba) and Manilkara huberi (maçaranduba), using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR-ATR), and direct infusion mass spectrometry (DIMS). Wood samples were subjected to controlled heating rates of 20, 40, and 60 °C/min from 25 to 800 °C under an argon atmosphere. TGA revealed moisture evaporation below 120 °C, with hemicellulose degradation occurring between 220 and 315 °C, cellulose decomposition between 315 and 400 °C, and lignin breakdown over a broader range from 180 to 900 °C. The highest rate of mass loss occurred at 363.99 °C for G. glabra and 360.27 °C for M. huberi at a heating rate of 20 °C/min, with shifts to higher temperatures at faster heating rates. Activation energies were calculated using Arrhenius and Kissinger models, yielding values between 53.46–61.45 kJ/mol for G. glabra and 58.18–62.77 kJ/mol for M. huberi, confirming their stable thermal profiles. DSC analysis identified a significant endothermic peak related to moisture evaporation below 100 °C, followed by two exothermic peaks. For G. glabra, the first exothermic peak appeared at 331.45 °C and the second at 466.08 °C, while for M. huberi, these occurred at 366.41 °C and 466.08 °C, indicating the decomposition of hemicellulose, cellulose, and lignin. Enthalpy values for G. glabra were 12,633.37 mJ and 18,652.66 mJ for the first and second peaks, respectively, while M. huberi showed lower enthalpies of 9648.04 mJ and 14,417.68 mJ, suggesting a higher energy release in G. glabra. FTIR-ATR analysis highlighted the presence of key functional groups in both species, with strong absorption bands in the 3330–3500 cm−1 region corresponding to O-H stretching vibrations, indicative of hydroxyl groups in cellulose and hemicellulose. The 1500–1600 cm−1 region, representing aromatic C=C vibrations, confirmed the presence of lignin. Quantitatively, these results suggest a high content of cellulose and lignin in both species. DIMS analysis further identified polyphenolic compounds and triterpenoids in M. huberi, with major ions at m/z 289 and 409, while G. glabra showed steroidal and polyphenolic compounds with a base peak at m/z 395. These findings indicate the significant presence of bioactive compounds, contributing to the wood’s resistance to microbial degradation. This comprehensive thermal and chemical characterization suggests that both species have potential industrial applications in environments requiring high thermal stability.

Contemporary Approaches to Wound Burn Healing

The World Health Organization (WHO) reports that over 11 million individuals get burns annually, resulting in 180,000 fatalities. A burn is a condition resulting by heat, chemical agents, electrical currents, or other forces that inflict tissue damage. Burns primarily impact the skin, however they may also include deeper structures, including bones and muscles. Upon combustion, the skin forfeits its primary functions, including protection against the external environment, infections, moisture evaporation, and thermal regulation. Based on the burn's stage, the patient's health, and the burn's etiology, it is essential to choose the most suitable therapy. Personalization and interdisciplinary teamwork are essential for the effective therapy of burn victims. This thorough study compiles and examines the existing treatment modalities, emphasizing current advancements in topical therapies, wound debridement, dressings, skin grafting, nutritional support, pain management, and scar tissue therapy.

Numerical Study on the Variable-Temperature Drying and Rehydration of Shiitake

Variable-temperature convective drying (VTCD) is a promising technology for obtaining high-quality dried mushrooms, particularly when considering rehydration capacity. However, accurate numerical models for variable-temperature convective drying and rehydration of shiitake mushrooms are lacking. This study addresses this gap by employing a model with thermo–hydro and mechanical bidirectional coupling to investigate five dehydration characteristics (moisture ratio, drying rate, temperature, evaporation rate, and volume shrinkage ratio) and a drying load characteristic (enthalpy difference) during VTCD. Additionally, a mathematical model combining drying and rehydration is proposed to analyze the effect of VTCD processes on the rehydration performance of shiitake mushrooms. The results demonstrate that, compared to constant-temperature drying, VTCD-dried mushrooms exhibit moderate shrinkage rates and drying time (16.89 h), along with reduced temperature variation and evaporation rate gradient (Max. 1.50 mol/(m3·s)). VTCD also improves enthalpy stability, reducing the maximum drying load by 58.84% compared to 338.15 K constant-temperature drying. Furthermore, drying time at medium temperatures (318.15–328.15 K) greatly influences rehydration performance. This study quantitatively highlights the superiority of variable-temperature convective drying, offering valuable insights for optimizing the shiitake mushroom drying processes.

Global influence of soil texture on ecosystem water limitation.

Low soil moisture and high vapour pressure deficit (VPD) cause plant water stress and lead to a variety of drought responses, including a reduction in transpiration and photosynthesis1,2. When soils dry below critical soil moisture thresholds, ecosystems transition from energy to water limitation as stomata close to alleviate water stress3,4. However, the mechanisms behind these thresholds remain poorly defined at the ecosystem scale. Here, by analysing observations of critical soil moisture thresholds globally, we show the prominent role of soil texture in modulating the onset of ecosystem water limitation through the soil hydraulic conductivity curve, whose steepness increases with sand fraction. This clarifies how ecosystem sensitivity to VPD versus soil moisture is shaped by soil texture, with ecosystems in sandy soils being relatively more sensitive to soil drying, whereas ecosystems in clayey soils are relatively more sensitive to VPD. For the same reason, plants in sandy soils have limited potential to adjust to water limitations, which has an impact on how climate change affects terrestrial ecosystems. In summary, although vegetation-atmosphere exchanges are driven by atmospheric conditions and mediated by plant adjustments, their fate is ultimately dependent on the soil.

Influence of moisture content and inlet temperature on the incineration characteristics of municipal solid waste (MSW)

Incineration is an effective method for the treatment of municipal solid waste, pre-treatment reduces the waste moisture content to increase the incineration performance. However, the inlet temperature variation influenced by the environment is often ignored at this stage, and the coupling of moisture content and inlet temperature directly affects the incineration performance. To investigate the optimal inlet conditions for the incineration, the numerical model of a 600 t/d incinerator was established according to a reference case. Detailed analyses of the combustion characteristics of the bed and furnace is conducted under various moisture contents and inlet temperatures. The incineration efficiency under multiple factors is analyzed using response surface methodology, with sensitivity to these factors derived from the surface derivative. The results indicate that at an inlet temperature of 30 °C, the rates of volatile release and fixed carbon combustion are negatively correlated with the moisture content, and maximum incineration efficiency of 39.02 % is reached at a moisture content of 28.12 %. At a moisture content of 33.26 %, The rates of moisture evaporation, volatile release, and fixed carbon combustion are positively correlated with inlet temperature, and the maximum incineration efficiency of 38.76 % is achieved at an inlet temperature of 40 °C. The incineration efficiency exhibits a negative sensitivity to moisture content, whereas its sensitivity to inlet temperature is contingent upon the specific temperature range. The combination of 26.53 % moisture content and 40.86 °C inlet temperature yields the highest incineration efficiency of 40.69 %. The findings of this study provide useful information for the pre-treatment of municipal solid waste, contributing to the enhancement of operational efficiency in waste-to-energy plants.

Thermodynamic Justification for the Effectiveness of the Oxidation—Soda Conversion of Ilmenite Concentrates

This article presents the results of a thermodynamic analysis of the oxidation soda conversion reactions of minerals in ilmenite concentrates in the temperature range of 373–2273 K. The thermodynamic parameters of pseudorutile, pseudobrukite, and the new minerals, zhikinite and spessartine, were calculated for the first time. It has been established that the most important criterion relating to the stability of titanium minerals and related elements, as well as the reaction properties of the structural oxides of metals and silicon, is their degree of oxidation. Oxides of silicon (IV) and manganese have the best reactivity in solid-phase oxidizing alkaline environments (VI). Modeling this process scientifically substantiates the mechanism involved in the destruction of minerals in ilmenite concentrates in the low-temperature region in the presence of atmospheric oxygen and sodium oxide of soda ash, which are decomposed through the absorption of heat and the evaporation of moisture during the dehydration of hydrated minerals of iron and manganese and the dehydration of the soda–ilmenite batch. Tests conducted during pilot metallurgical production at the Institute of Metallurgy and Enrichment (PMP of JSC) confirmed the feasibility of processing high-chromium and siliceous rutile leucoxene ilmenite concentrates, which are unsuitable for traditional pyro- and hydro-metallurgical enrichment methods, through single-stage oxidation soda roasting, followed by the leaching of easily soluble sodium salts of iron and associated impurities with water and a dilute hydrochloric acid solution. The proposed energy-saving method ensures the production of high-purity (>98%) synthetic rutile while eliminating the formation of strong deposits on the lining of roasting units.

Flash Drought Intensification due to Enhanced Land–Atmospheric Coupling in India

Abstract Land–atmospheric feedback influences the occurrence and severity of flash droughts. However, the observed and projected changes in flash droughts and associated land–atmospheric coupling have not been examined over India. Moreover, the causes of the rapid depletion of soil moisture during flash droughts are not well known. We identify major flash droughts and associated soil moisture–vapor pressure deficit (SM–VPD) coupling in India using ERA5 and simulations from global climate models (CMIP6-GCMs). The summer monsoon season (June–September) witnesses more than 60% of the flash drought events and a relatively higher rate of flash drought development. The flash drought frequency has mainly decreased during India’s observed climate (1980–2019), which is projected to decline further in the future warming climate. On the other hand, the flash drought development rate has significantly increased during the observed period, which is projected to enhance further under the warming climate. SM–VPD coupling during the flash drought onset-development phase is considerably higher (threefold to fivefold) than during the normal condition (in the absence of flash drought). The high (low) SM–VPD coupling explains the faster (slower) flash drought development rate in the observed and future warming climate. The strength of SM–VPD coupling has increased in the recent period and is projected to increase further in the future warming climate. The increased SM–VPD coupling can intensify future flash droughts in India, especially during the summer monsoon season, with considerable implications for agriculture, water resources, and ecosystems. Significance Statement This study aims to understand better the role of land–atmospheric coupling in explaining flash drought characteristics (frequency and development rate) in India. Strong land–atmospheric (SM–VPD) feedback might influence the regional weather patterns during flash drought, which often negatively impacts humans and the ecosystem. We explain the causes and drivers of increasing (decreasing) flash drought development rate (frequency) in India. The long-term change in SM–VPD coupling drives the frequency of flash drought, whereas an anomalous instantaneous change in coupling controls the flash drought development rate. More intense flash droughts contributed by the increased land–atmospheric coupling are projected in the future. Predicting the SM–VPD coupling metric can facilitate more time for preparedness, resulting in minimizing the flash drought impacts.

Assessing the impact of moisture buffering properties of materials on indoor environmental quality: A study on a recycled material plaster

This study examines Moisture Buffer Value (MBV) of interior finishing layers, which impacts buildings internal relative humidity, thus indoor environmental quality. The MBV depends on material's moisture capacity and vapour diffusion resistance factor, both of which depends on relative humidity. The paper aims to (i) characterize a new recycled material plaster that includes construction and food industry waste through laboratory measurements, (ii) use dynamical building simulations to quantify the impact of the MBV of existing and the new interior plaster on relative humidity in real design scenarios, and (iii) evaluate how changing the definition of the MBV to consider its dependence on indoor air relative humidity can improve its accuracy. Results show that the plaster's moisture buffering properties significantly reduce the variations of the relative humidity of interior climates compared to a vapour-tight finishing layer. The performances of the new plaster made with recycled materials are comparable to those of the other plasters. The new MBV definitions (“Dynamical MBV″ and “Summer/Winter MBV”) show a significantly improved correlation with the relative humidity variations of indoor climates of buildings, observed in dynamic simulations, with respect to the typically used practical MBV. The new definitions are therefore promising for practical applications.

Experimental investigation on the moisture movement behavior of granites

This study comprehensively investigates the hygric performance of two commonly used types of granite in masonry, each characterized by distinct porosity levels. A series of experimental tests, including capillary absorption, one-dimensional drying, cup methods, vacuum saturation, sorption/desorption isotherms, mercury intrusion porosimetry, and ultrasonic pulse velocity, was conducted in different directions and by using both pure water and NaCl solutions. The results highlight pronounced anisotropy in the granite’s hygric response, with significant directional differences in liquid and vapor moisture movement, as well as ultrasonic wave propagation. Granite with lower porosity and a finer pore structure exhibited hysteresis effects and more pronounced hygroscopic behavior, while granite with higher porosity showed greater capillary activity. The presence of salt crystals within the pore network significantly influences vapor and liquid transport properties, porosity, and moisture storage capacity. The gradual formation of sodium chloride crystals on drying surfaces noticeably altered drying kinetics, influenced by salt concentration and pore characteristics. These findings provide valuable insights into the hygric properties of granite, essential for understanding its durability and informing moisture transfer numerical models.

Field investigation of soil moisture profile in the seedbeds of clayey paddy fields composed of large clods (aggregates)

ABSTRACT Unstable germination and emergence of upland crops in clayey paddy fields is a pressing issue. As tillage leads to the formation of large clods measuring a few centimeters, the soil moisture content in the seedbed markedly decreases, potentially inhibiting germination of seeds. Although the effect of the clod size on the soil moisture profile was confirmed experimentally, the validity of this effect has not been tested in the field. In this study, we aimed to clarify the effect of clod size on the moisture profile and water balance in the seedbeds of clayey paddy field. We developed an apparatus for measuring soil moisture content in the soil layer with clods. This apparatus used a laser displacement sensor and large transparent plate horizontally fixed above the soil surface. Temporal changes in the soil moisture profile (0–10 cm depth) and evaporation rate of clayey paddy fields with different clod sizes were monitored during the sowing period of soybeans. We found that the larger the mean clod diameter (MCD), the greater the decrease in soil moisture content near the soil surface. In addition, soil moisture loss at the sowing depth (5 cm) was positively correlated with MCD. In terms of the water balance, the estimated upward water flux at a depth of 5 cm was less than 1 mm d−1 across all the plots and periods. By contrast, the estimated ratio of the apparent to molecular diffusion coefficient of water vapor in the dry soil layer of clayey paddy field with an MCD of 2.5 and 1.8 cm were 5.1 and 2.0, respectively. These results suggest that more significant soil moisture loss causing reduction of germination and emergence rate can occur in a clayey paddy field with large clods, likely owing to the increased enhancement of water vapor movement. To increase the germination and emergence rate, therefore, a numerical model that can evaluate the moisture profile of soil layer with clods should be developed and the sowing depth should be optimized based on the MCD.

Melt-Processed Polybutylene-Succinate Biocomposites with Chitosan: Development and Characterization of Rheological, Thermal, Mechanical and Antimicrobial Properties.

The current research is devoted to the development and characterization of green antimicrobial polymer biocomposites for food packaging applications. The biocomposites were developed by melt compounding on the basis of two different succinate polymer matrices with varying chain stiffness-polybutylene succinate (PBS) or its copolymer with 20 mol.% of polybutylene adipate (PBSA). Fungi chitosan oligosaccharide (C98) and crustacean chitosan (C95) were used as antimicrobial additives. The rheological properties of the developed biocomposites were determined to clear out the most suitable temperature for melt processing. In addition, mechanical, thermal, barrier and antimicrobial properties of the developed biocomposites were determined. The results of the investigation revealed that PBSA composites with 7 wt% and 10 wt% of the C98 additive were more suitable for the development of green packaging films because of their higher ultimate elongation values, better damping properties as well as their superior anti-microbial behavior. However, due to the lower thermal stability of the C98 additive as well as PBSA, the melt processing temperatures of the composites desirably should not exceed 120 °C. Additionally, by considering decreased moisture vapor barrier properties, it is recommended to perform further modifications of the PBSA-C98 composites through an addition of a nanoclay additive due to its excellent barrier properties and thermal stability.

Pyrolysis of Khat waste vs. Coal: Experimental and Aspen plus analysis

This study explores the potential of Khat waste as a biofuel through a detailed analysis of its physical properties and pyrolytic behavior, employing both laboratory and simulation techniques. Biomass, including Khat waste, is a valuable renewable energy source with potential applications in reducing waste and CO2 emissions, especially in rural areas of developing countries like Ethiopia. The physical properties of the Khat waste were thoroughly examined, including moisture content, ash, volatile matter (VM), fixed carbon (FC), and elemental composition. The apparent density of the pyrolyzed khat waste was found to be 0.9688 g/cm³. The TGA results showed a moisture loss of 6.7 %, volatile matter of 4.7 %, fixed carbon of 6.78 %, and ash content of 5.55 %. Notably, Khat waste exhibited unique thermal behavior with a downward shift in TG curves above 220 °C. DTGA identified three decomposition peaks: moisture evaporation at 100 °C, hemicellulose breakdown at 210 °C, and cellulose degradation at higher temperatures. Fourier Transform Infrared Spectroscopy (FTIR) provided insights into the functional groups present in Khat waste, including alkene functional groups and O-H bonds, which are crucial for biofuel properties. Simulation using Aspen Plus software modeled the pyrolysis process, highlighting how varying heating rates affect volatile matter and fixed carbon content. Increasing heating rates decreased volatile matter and moisture but increased fixed carbon content. These findings offer valuable insights for optimizing Khat waste as a biofuel, emphasizing the need for tailored pyrolysis conditions to enhance biofuel production efficiency.

Investigation of Photoinduced Deterioration in Shadow Puppet Artifacts Collected from the National Shadow Pupperty Museum in Chengdu, China

Shadow puppet artifacts are a special type of cultural heritage made from animal skin, possessing significant cultural and artistic value. However, there is insufficient attention to the scientific preservation of these artifacts, and systematic research on their protection is lacking. In particular, light as an important factor and related conservation studies are weak. This study investigates the photoinduced deterioration of shadow puppet artifacts from the National Shadow Pupperty Museum in Chengdu collection. Based on the xenon arc lamp are a common method of light aging, the modern rawhide samples were aged by the xenon arc lamp to simulate photoinduced deterioration. After artificial light aging, the samples were stored in a stable environment (with temperature maintained at 22 ± 2°C and relative humidity maintained at 50 ± 5%RH) for 150 days. It attempts to avoid further deterioration of the samples due to drastic cyclic changes in the environment. And continuously observe changes in characteristics during this process to verify the potential reversibility of photoinduced deterioration. Comprehensive assessments were conducted to gauge the extent of deterioration. In order to assess the deterioration, a series of analytical techniques were used. Moisture gain or loss was inferred from mass changes, and colorimetric measurements were measured using the CIELAB formula. Macroscopic and microscopic morphological damage was documented through camera, stereo microscope, and scanning electron microscope observations. Fourier transform infrared spectroscopy (FTIR) assessed amide bond degradation and moisture loss, while thermogravimetry/differential thermogravimetry (TG/DTG) evaluated collagen denaturation and thermal stability. The results indicated that prolonged light exposure caused significant deterioration, including color fading, moisture evaporation, and structural damage such as shrinkage and cracking. The findings indicate that light exposure is a crucial factor in the preservation of shadow puppet artifacts. Therefore, it is essential to implement careful management strategies in museum environments to ensure the protection of these artifacts.

Effect of water occurrence in coal reservoirs on the production capacity of coalbed methane by using NMR simulation technology and production capacity simulation

The occurrence of gas and water is a critical factor affecting the production capacity of coalbed methane. Therefore, occurrence and dynamic interaction between gas and water in coal reservoirs need to be studied. T2 spectrum of all the samples were studied by NMR technique at 0, 5, 9, and 28 h of natural evaporation. Then, multifractal model was used to characterize water distribution heterogeneity, and a novel evaluation coefficient was proposed to characterize distribution heterogeneity of water content, the correlation among evaluation coefficient, water distribution heterogeneity and pore structure parameters was analyzed. The results are as follows. In the saturated state, the moisture distribution of three types is heterogeneous. Type A of adsorption pore-developed exhibits strong moisture variation heterogeneity of small pores, in contrast to the uniform moisture variation in large pores. Type B of fracture-developed has the highest coefficient of variation in moisture distribution. The coefficient of variation A1 for moisture content can determine the speed of moisture transport and evaporation in the pore structure. A lower A1 indicates a greater moisture transport volume and faster moisture transport rate over the same time. The coefficient of variation A2 for moisture distribution represents the heterogeneity of moisture content variation in the pore structure. That is, a smaller A2 indicates better heterogeneity in the distribution of moisture content in the pore structure. Numerical simulation indicates the average gas production and the peak gas production time increase and decrease with the initial moisture content (Sgrw) increases, respectively. These findings provide practical guidance for coalbed methane development, especially in optimizing coalbed methane production capacity prediction and improving recovery efficiency.

Spider web-reinforced chitosan/starch biopolymer for active biodegradable food packaging

In this study, starch (ST), chitosan (CH), spider silk (SW), and their hybrid composite bioplastics were fabricated and examined for physicochemical and mechanical properties. The essential oils (EOs) of Rosmarinus officinalis were encapsulated to enhance their biological application. The prepared composite films were characterized using various spectroscopic techniques such as XRD, SEM, GCMS–, UV–VIS, TGA, and FTIR spectroscopy. The antimicrobial activity of the prepared film was tested against S. aureus bacterial and C. albican fungal strains which showed a greater zone of inhibition for the composite film encapsulated with EOs. The biodegradability of the synthesized film was evaluated for 60 days in soil under laboratory conditions. The composite film containing spider web and essential oil significantly improved mechanical properties. The physicochemical results, such as moisture, solubility, swelling, transmittance, opacity, and water vapor permeability, of the prepared bioplastic were comparable with those of the control plastic. The EO-based film had greater antioxidant activity against DPPH, hydrogen peroxide, and phosphomolybdenum assays, with an inhibition range of 60–70 %. The addition of spider web and essential oil to the chitosan/ starch film significantly increased the shelf life of injera and tomatoes for 7 and 10 days, respectively for the EO-based film. The biodegradability of the synthesized film has shown a great reduction in the weight and growth of microorganisms. In general, the CH/ST/SW and CH/ST/SW/EOs composite films have greater mechanical, biological, physicochemical, and potential improvement of food shelf life applied as either coating or packaging material.

Hazardous waste alternative fuels to novel ecological energy: Combustion characteristics and effects on clinker's environmental safety

Due to their detrimental and persistent impacts on the environment, it is imperative to manage and dispose of hazardous wastes (HW) in a secure manner. This study investigates the combustion characteristics and environmental impacts of using HW as alternative fuels in clinker production. The HW categories analyzed include industrial hazardous waste (IHW), medical hazardous waste (MHW), and household hazardous waste (HHW). Specifically, IHW consists mainly of waste mineral oils, waste organic solvents, organic resin wastes, waste residues, and waste coatings. MHW primarily consists of medical plastic products. HHW mainly includes packaging from waste pharmaceuticals, waste pesticides, disinfectants, and waste paints. Compared to traditional pulverized coal, hazardous waste alternative fuel (HWAF) exhibits a lower fixed carbon content, with its heat generation primarily dependent on volatile substances, and a higher ash content, chemically similar to coal ash. The combustion process of HWAF involves three stages: moisture evaporation (0 °C–150 °C), volatile matter combustion (150°C–400 °C), and fixed carbon combustion (400 °C–550 °C). The primary emissions from this process include CO2, CO, trace amounts of SO2, NO2, H2O, and various complex organic compounds such as carboxylic acids, alcohols, ketones, and aldehydes. While HWAF ignites more readily than pulverized coal, it burns more slowly and less completely. The incorporation of combustion by-products into the cement clinker formulation does not interfere with the clinker's hydration processes or reactions. HWAF ensures a reduced heavy metal input rate in the firing system without significantly impacting the heavy metal content in the clinker. Mortar samples produced with this clinker meet the heavy metal leaching standards, affirming the environmental safety of the cement product. Increasing the proportion of HWAF results in a reduction in standard coal consumption and an increase in CO2 reduction, achieving a maximum coal saving of 3.67 kgce/t.cl and a CO2 emission reduction of 10.11 kg/t.cl. This study presents a clean production model for the co-processing of HWAF, effectively transforming waste into valuable resources by using hazardous waste materials as alternative fuels.

Wearable Device with High Thermoelectric Performance and Long-Lasting Usability Based on Gel-Thermocells for Body Heat Harvesting.

Utilizing the thermogalvanic effect, flexible thermoelectric materials present a compelling avenue for converting heat into electricity, especially in the context of wearable electronics. However, prolonged usage is hampered by the limitation imposed on the thermoelectric device's operational time due to the evaporation of moisture. Deep eutectic solvents (DESs) offer a promising solution for low-moisture gel fabrication. In this study, a bacterial cellulose (BC)/polyacrylic acid (PAA)/guanidinium chloride (GdmCl) gel is synthesized by incorporating BC into the DES. High-performance n-type and p-type thermocells (TECs) are developed by introducing Fe(ClO4)2/3 and K3/4Fe(CN)6, respectively. BC enhances the mechanical properties through the construction of an interpenetrating network structure. The coordination of carboxyl groups on PAA with Fe3+ and the crystallization induced by Gdm+ with [Fe(CN)6]4- remarkably improve the thermoelectric performance, achieving a Seebeck coefficient (S) of 2.4mVK-1 and ion conductivity (σ) of 1.4 Sm-1 for the n-type TEC, and ‒2.8mVK-1 and 1.9 Sm-1 for the p-type TEC. A flexible wearable thermoelectric device is fabricated with a S of 82mVK-1 and it maintains a stable output over one month. This research broadens the application scope of DESs in the thermoelectric field and offers promising strategies for long-lasting wearable energy solutions.

Investigate on spontaneous combustion characteristics of lignite stockpiles considering moisture and particle size effects

Coal spontaneous combustion (CSC) threatens the safety of the coal industry, with moisture content and particle size being pivotal factors. This study examines the heating dynamics and critical self-ignition temperatures (CSITs) of Baiyinhua lignite stockpiles through wire-mesh basket (WMB) tests at two scales. The CSC process in coal stockpiles unfolds in four stages. Notably, Stage II is notable for significant moisture evaporation between 43 and 84 °C, while Stage IV marks the onset of self-heating. Moisture evaporation absorbs heat, linearly prolonging the Stage II duration, which accounts for 0%–70 % of the total time. Conversely, larger particle sizes enhance pore seepage, effectively shortening the heating time. The time for d = 20 mm (particle size) coal sample to reach ambient temperature is roughly half that of 1.5 mm. CSITs of raw coal increase by 10–15 °C compared to the dry coal, and CSIT of coal samples with d = 50 mm has increased by 17.5 °C compared to 10 mm. Therefore, both an increase in particle size and moisture content increase the CSIT, thereby reducing the propensity for CSC. Frank-Kamenetskii theory and dimensionless analysis predict spontaneous combustion risks in field-scale coal stockpiles. This investigation contributes valuable insights to the estimation and prevention of CSC.

Kinetic analysis and calculation correction methods for moisture evaporation rate in pine lignocellulosic biomass

This study investigates the kinetics of moisture evaporation in pine wood during the drying stage, focusing on analyzing thermogravimetric (TG) curves. The research is based on the kinetic rate model and TG curves obtained at various heating rates, specifically 5, 10, 15, and 20 K/min for the heat release rate, within a temperature range from room temperature to 473 K. Utilizing thermogravimetric experiments and the kinetic rate model, the apparent activation energy and pre-exponential factor are calculated. Further refinement of these calculations is achieved using the Nelder-Mead algorithm. The results show good agreement between the average values of the apparent activation energy (37.88 kJ/mol) and pre-exponential factor (4458.20 s−1) and experimental measurements in the initial and later drying stages, with discrepancies noted in the middle stage. Establishing a relationship between the correction coefficients of these parameters and the heating rate leads to a reduction in calculation errors. Notably, the pre-exponential factor is found to be influenced by heating rates, while the apparent activation energy remains relatively stable. Moreover, the errors are significantly reduced after correction, and the error curve of 10 K/min is the most significant. Overall, the proposed correction method holds promise for accurately calculating moisture evaporation rates in lignocellulosic biomass, offering valuable insights for biomass drying applications.

Surface weathering process of earthen heritage under dry-wet cycles: A case study of Suoyang City, China

Dry-wet cycle is a key factor in surface weathering of earthen heritage, which remains insufficiently explained. It involves the interaction of humidity, stress, and damage. Using the RFPA (realistic failure process analysis) numerical method, this study reproduced the processes of humidity diffusion, deformation, stress, and damage evolution under dry-wet cycles in the soil site of Suoyang City, China. The numerical results indicate that the drying phase following rainfall has the most significant deteriorative impact on the earthen heritage. The evaporation of surface moisture during this phase causes volume shrinkage, which in turn generates tensile stress and leads to the formation of numerous desiccation cracks. Desiccation cracks provide channels for moisture diffusion, which further exacerbates generation of the cracks, leading to a mutual promotion between the two phenomena. Furthermore, during the wetting phase, the model elements undergo hygroscopic expansion, resulting in a slight increase in strain and displacement. Previously formed cracks may exhibit temporary narrowing or closure, but will revert during the subsequent drying phase. Ultimately, the overall displacement increases with the number of dry-wet cycles. The findings provide a theoretical foundation for protection against surface weathering and other damage in earthen heritage in arid regions.