Treatment Temperature Research Articles

Straightforward Synthesis Methodology for Obtaining Excellent ORR Electrocatalysts From Biomass Residues Through a One Pot‐High Temperature Treatment Approach

AbstractMaterials prepared from biomass residues are potential candidates to substitute the Pt‐based commercial electrocatalysts in oxygen reduction reaction (ORR). Although some investigations have reported activity and durability comparable to Pt/C using biomass‐derived catalysts based on Fe─N─C sites, it remains a challenge to decrease the environmental impact of the production of these materials. A straightforward procedure is developed to obtain excellentORR electrocatalysts from biomass residues which requires a single high‐temperature treatment. The final washing step is avoided by optimizing the initial amount of Fe precursor (FeC2O4). Besides the formation of iron oxide nanoparticles, a highly dispersed Fe phase is detected by High Angle Annular Dark Field Scanning Transmission Electron Microscopy and Energy Dispersive X‐Ray Spectroscopy (HAADF‐STEM‐XEDS) analysis as well as graphitic carbon structures. The best performance for almond shell‐based electrocatalysts is achieved for the sample containing 4.6 wt. % of Fe. The procedure developed is also applied to oceanic posidonia and eucalyptus residues, also showing excellent ORR behavior. The best sample is studied in a primary Zn‐air battery (ZAB) obtaining a maximum power density of 59 mW cm−2 and 755 mAh gZn−1 capacity.

Influence of Solution Treatment Temperatures on LPBF-Produced Inconel 939 Alloy on Mechanical Performance

This study investigates the influence of solution treatment temperatures on the microstructure and mechanical properties of LPBF (Laser Powder Bed Fusion)-manufactured Inconel 939 alloy. The primary objectives are to assess the impact of sub-recrystallization (below recrystallization temperature) and recrystallization temperatures during solution treatment on mechanical performance under different conditions. This study validates the hypothesis concerning carbide redistribution and mechanical performance in LPBF-produced Inconel 939 parts through comprehensive analysis, including microstructure studies and tensile tests. The results indicate that higher heat treatment temperatures lead to significant changes in carbide redistribution and mechanical performance. For instance, at room temperature, the specimen with sub-recrystallization solution treatment temperature exhibited superior mechanical properties compared to both the as-built and recrystallization-temperature solution treatment specimens. However, at elevated temperatures (700 °C), a reversal in mechanical anisotropy was observed, with the vertical axis demonstrating higher tensile strength compared to the horizontal axis for all material states. Furthermore, a microstructural analysis revealed distinct changes in grain structure and precipitate distribution, particularly the migration of carbides from grain boundaries to intragranular regions. These findings underscore the importance of precise control over heat treatment parameters to achieve optimal mechanical behavior. This research provides valuable insights into optimizing LPBF processes for the Inconel 939 alloy, highlighting the need for a meticulous control of the solution treatment parameters to ensure mechanical integrity. The findings contribute to a broader understanding of material-specific responses in additive manufacturing, with significant implications for aerospace applications.

Effect of Synthesis Process on The Piezoelectric Properties of (1-x) NBT-xBT: A Comparative Study Between Solid State and Hydrothermal Methods

Lead-free oxide perovskite materials are produced to ensure that no toxic or dangerous waste is released into the environment, although this technique often requires a high-temperature synthesis method. Nevertheless, the development of an environmentally friendly chemical process to carry out the synthesis of perovskite material in the laboratory at low temperature is a major challenge. In this investigation, to lower the temperature of the thermal treatment, (1-x)(Na0.5Bi0.5)TiO3-xBaTiO3 (abbreviated as (1-x)NBT-xBT) ceramics were synthesized using two different methods: a hydrothermal method and a conventional calcination process (solid-state), using the same reagents. The effects of various synthesis techniques on the composition, structure, morphology, and dielectric properties of the (1-x)NBT-xBT ceramics were registered and examined. The XRD plots taken at ambient temperature were used to verify the phase formation of the samples. The occurrence of functional bands was also verified by Raman spectroscopy at ambient temperature. Using the Rietveld refinement method were able to detect the morphotropic phase boundary (MPB) near x=0.05-0.07. When the hydrothermal process was adopted, the (1-x)NBT-xBT ceramics show a single perovskite structure sintered at 1000°C. Moreover, scanning Electron Microscopy (SEM) examination revealed a uniform distribution of grains and a significant change in grain size with the increase in BaTiO3 concentration when compared to the conventional method. The microstructure of ceramics is generally strongly influenced by the method used to prepare the powders, which has a considerable impact on their performance. Piezoelectric and dielectric properties of the specimens have been compared with the properties of those prepared by the hydrothermal process. Thus, the choice of the suitable synthesis method depends on the desired properties of the (1-x)NBT-xBT materials.

Physically and chemically modified zeolite templated nitrogenous carbons for enhanced hydrogen adsorption

Carbon materials have great potential for hydrogen adsorption due to their remarkable specific surface area, unique pore size characteristics and ability to functionalize with metal or non-metal. In this work, zeolite templated carbons were physically and chemically modified by varying preparation conditions to study their impact on structure and hydrogen adsorption capacity. The resultant templated carbons showed surface area in the range of 608–1665 m2/g and pore volume between 0.63 to 1.00 cc/g, with 28–48 % microporosity depending on synthesis conditions. The surface area and pore volume increased with increasing carbon deposition temperature from 650 to 750 °C and both decreased at higher carbon deposition temperature of 850 °C. At heat treatment temperature of 900 °C, the surface area and pore volume of templated carbons were observed to be higher. Incorporation of nitrogen heteroatom in carbon matrix during carbon deposition might have facilitated porosity. Use of argon as carrier gas resulted in the highest surface area (1665 m2/g), micropore area (597 m2/g) and pore volume (1.0 cc/g). The same templated carbon showed maximum hydrogen adsorption capacity of 0.20 and 2.81 wt% at 25 and –196 °C, respectively at 15 bar. On addition of platinum to templated carbon, the hydrogen adsorption capacity was significantly improved from 0.20 to 0.28 wt% at 25 °C and from 2.81 to 3.24 wt% at –196 °C. The strong affinity of Pt for hydrogen might have enhanced hydrogen adsorption.

Study on the creep constitutive model of layered rockconsidering anisotropic and damage factors after hightemperature exposure

The failure of layered rock after high temperature exposure is a major concern in deep underground engineering projects. This paper proposes an improved Nishihara creep constitutive model that considers damage factors and the bedding angle, which overcomes the shortcomings of the deviation in the description of the conventional Nishihara model in the acceleration stage. The constitutive model is verified by the conventional triaxial creepiest. The theoretical curve has a high degree of fitting with the experimental curve. The experimental results show that a temperature of [Formula: see text] has an obvious influence on the steady creep rate and the creep strain of layered sandstone, and [Formula: see text] can be regarded as the temperature threshold for the long-term strength and change from anisotropic to isotropic of layered sandstone. The irreversible melting mixing phenomenon at the boundary of mineral particles with increasing temperature is the mechanism by which different treatment temperatures affect the anisotropy degree of layered rock.

Assessment of heat tolerance and identification of miRNAs during high-temperature response in grapevine.

With global warming, heat stress has been recognized as a significant factor limiting grapevine development and fruit quality. MicroRNAs (miRNAs) are a class of small non-coding RNAs known to play crucial regulatory roles in stress resistance. Hence, there is an immediate requirement to cultivate and identify grapevine varieties that are resistant to heat and explore miRNA-mediated heat stress defense mechanisms. In this study, we assessed the thermal resistance of 38 grape germplasm resources and identified a series of miRNAs involved in heat stress resistance. The CK (25°C) and HS (45°C) groups of "Shenyue" cuttings of grapes were used as experimental materials for next-generation sequencing and construct libraries of small RNAs. A total of 177 known and 20 novel miRNAs were detected in the libraries. Differential expression analysis identified 65 differentially expressed miRNAs (DEMs) using the DE-Seq procedure. Furthermore, RT-qPCR validation confirmed complementary expression profiles of eight DEMs and their target genes between the HS and CK groups. Heterologous transformation further identified the function of Vvi-miR3633a downregulated under heat stress in Arabidopsis. In the heterologous expression lines, the survival rate was reduced by high temperature treatment indicating the ability of Vvi-miR3633a to regulate heat resistance. Assessing the heat resistance of grape species and the expression patterns of miRNA in response to high temperatures may reveal the molecular processes of heat resistance regulation mediated by miRNA in grapes under heat stress.

Crystallization Behavior and Structure of CaO–SiO2–Al2O3 Melts Representing the Oxide Inclusions in Si‐Mn Deoxidized Steel

For further optimization of the inclusion plasticization control process of Si‐Mn deoxidized steel, the crystallization behavior and structure of CaO–SiO2–Al2O3 system inclusions are investigated. The crystallization behavior of four typical low melting point CaO–SiO2–Al2O3 inclusions at 1000 to 1250 °C is studied by steel crucible isothermal heating experiment. The obtained results reveal that the glassy stability of the inclusions is high when the composition of low melting point inclusion is located in the eutectic region of tridymite, pseudowollastonite, and anorthite in the ternary phase diagram. However, when the composition of the inclusion is located in the eutectic region of melilite, pseudowollastonite, and anorthite, it is easy to undergo glass‐crystallization transformation and precipitate wollastonite and anorthite crystalline phases when isothermal heating at 1100 to 1200 °C. In addition, the crystallization mode of these inclusions is mainly surface crystallization, and the crystallization degree of inclusions increases with the increase of heat treatment temperature and time. The activation energy of crystallization and the content of nonbridging oxygen in the silicate structure NBO/T can be used to predict the crystallization ability of inclusions. The greater the activation energy of crystallization and the smaller the NBO/T value, the higher the glassy stability of the inclusions.

Preservation with Different Smoking Techniques to Extend the Shelf Life of “Urutan” Chicken

“Urutan” chicken is one of the processed meat products processed through the manufacture of meat dough, fat and complete Balinese spices ("Basa Genep"). Extending the shelf life of “urutan” chicken can be done by smoking process either by cold smoking method or hot smoking. Smoke can preserve food ingredients due to the presence of acid, phenolic and carbonyl compounds. The method used in this study is Randomized Block Design (RBD) with a factorial pattern consisting of 2 factors, namely Factor I is Hot Smoking Technique consisting of 3 levels and Factor II is Smoking Time consisting of 4 levels so that 12 treatment combinations are obtained and 2 repetitions are carried out so that 24 experimental units are obtained. The parameters observed include phenol content, water content, ash content, fat content, protein content, Esherichia coli and Salmonella sp. Statistical analysis shows that smoking time has a significant effect (sig <0.05) on the phenol content of “urutan” chicken, but does not have a significant effect (sig> 0.05) on the fat and protein content of “urutan” chicken. The fat content of “urutan” chickens in the smoking duration treatment at a temperature of 100 ° C ranged from 9.798 - 11.870%. The lowest fat content was obtained in 2 hours of smoking, which was 9.798% which was not significantly different from other treatments. The protein content of “urutan” chickens in the smoking treatments of 0.5, 1, 1.5 and 2 hours ranged from 11.788 -12.197%. The smoking duration did not have a significant effect on the protein content of “urutan” chickens, which was probably because the smoking duration of 0.5 -2 hours had not denatured the protein sequence. The phenol content of “urutan” chickens in the smoking treatments of 0.5, 1, 1.5 and 2 hours ranged from 0.206 - 0.312%. The highest phenol content was obtained in 2 hours of smoking at a smoking temperature of 100 ° C, which was 0.312%. The results showed that the longer the smoking, the higher the phenol content of “urutan” chickens. The lowest pH value was obtained in the 100 °C 2-hour smoking treatment of 5.16, which was significantly different from other treatments. The highest water content was obtained in the 100 °C 2-hour temperature treatment of 63.19%, which was significantly different from other treatments

Transcriptomic Analysis of Hippocampus abdominalis Larvae Under High Temperature Stress.

Acute temperature stress was explored in Hippocampus abdominalis through a comprehensive RNA-seq analysis. RNA-seq was conducted on 20-day-old H. abdominalis after 24 h of temperature stress. Four experimental conditions were established: a control group (18 °C) and three temperature treatment groups (21, 24, and 27 °C). Seahorse larvae were found to be unaffected by 21 °C and 24 °C and were able to survive for short periods of time during 24 h of incubation, whereas mortality approached 50% at 27 °C. The sequencing process produced 75.63 Gb of high-quality clean data, with Q20 and Q30 base percentages surpassing 98% and 96%, respectively. A total of 141, 333, and 1598 differentially expressed genes were identified in the 21, 24, and 27 °C groups vs. a control comparison group, respectively. Notably, the number of up-regulated genes was consistently higher than that of down-regulated genes across all comparisons. Gene Ontology functional annotation revealed that differentially expressed genes were predominantly associated with metabolic processes, redox reactions, and biosynthetic functions. In-depth KEGG pathway enrichment analysis demonstrated that down-regulated genes were significantly enriched in pathways related to steroid biosynthesis, terpenoid backbone biosynthesis, spliceosome function, and DNA replication. Up-regulated genes were enriched in pathways associated with the FoxO signaling pathway and mitophagy (animal). The results indicated that temperature stress induced extensive changes in gene expression in H. abdominalis, involving crucial biological processes such as growth, biosynthesis, and energy metabolism. This study provided key molecular mechanisms in the response of H. abdominalis to temperature stress, offering a strong basis for future research aimed at understanding and mitigating the effects of environmental stressors on marine species.

The Influence of Thermal Treatment of Activated Carbon on Its Electrochemical, Corrosion, and Adsorption Characteristics

Activated carbons can be applied in various areas of our daily life depending on their properties. This study was conducted to investigate the effect of thermal treatment of activated carbon on its properties, considering its future use. The characteristics of activated carbon heat-treated at temperatures of 1500, 1800, and 2100 °C based on its future use are presented. The significant effect of the treatment temperature on morphological, adsorption, electrochemical, and corrosion properties was proved. Increasing the temperature above 1800 °C resulted in a significant decrease in the specific surface area (from 969 to 8 m2·g−1) and material porosity—the formation of mesopores (20–100 nm diameter) was observed. Simultaneously, adsorption capability, double layer capacity, and electrochemically active surface area also decreased, which helped to explain the shape of cyclic voltammograms recorded in 2,4-dichlorophenoxyacetic acid and in supporting electrolytes. However, a significant increase in corrosion resistance was found for the carbon material treated at a temperature of 2100 °C (corrosion current decreased by 23 times). Comparison of morphological, adsorption, corrosion, and electrochemical characteristics of the tested activated carbon, its applicability as an electrode material in electrical energy storage devices, and materials for adsorptive removal of organic compounds from wastewater or as a sensor in electrochemical determination of organic compounds was discussed.

Immunity Induction in Catfish (Clarias gariepinus) with Feed Containing Red Ginger Extract after High Temperature Treatment

This study aims to evaluate the effect of feeding feed containing red ginger extract on the immunity and survival of catfish (Clarias gariepinus) fingerlings exposed to high temperature conditions. The research was carried out experimentally with a Completely Randomized Design (CRD) consisting of four treatment doses of red ginger extract (A: 0 ml/kg, B: 30 ml/kg, C: 40 ml/kg, D: 50 ml/kg) and three replications. Parameters observed included survival rate, white blood cell count, red blood cell count. The results showed that the addition of red ginger extract to feed was able to increase catfish survival by up to 90% at a dose of 50 ml/kg. A significant increase in the number of white blood cells and red blood cells in fish given red ginger extract indicates a better immune response. Red ginger extract has proven effective in helping fish adapt to thermal stress by increasing immunity and resistance to high water temperatures.

Influence of bed temperature on the final properties of PLA parts manufactured by material extrusion

Purpose This paper aims to study the influence of bed temperature on the properties of printed parts and their structural stability. Design/methodology/approach Material extrusion is a manufacturing technique in which a part is completed layer by layer with molten filament. The first layer is deposited on a build platform called bed, which is usually at a controlled temperature above room temperature. The density, coefficient of thermal expansion and Young’s modulus were determined as a function of the bed temperature. The complex permittivity was determined at different temperatures, with the aim of analyzing the influence of the bed temperature and isothermal treatments on the characteristics of the amorphous phase. Findings The Young’s modulus presented a non-monotonic behavior, while the coefficient of thermal expansion did not present a clear dependence on the bed temperature. However, a contraction of the dimensions of the parts was observed after heating at temperatures above the glass transition. With treatments at temperatures lower than the glass transition temperature, no changes were observed. However, with treatments at temperatures higher than this, changes in the mobile amorphous region were inferred. Originality/value Issues related to the use of parts manufactured by 3D printing after a posterior heating were analyzed: an improvement in the Young’s modulus and a slight variation of the coefficient of thermal expansion were observed. However, a significant variation in dimensions was detected, mainly for the lowest bed temperatures. This is important for possible applications at temperatures above 60°C.

Effects of mineral fertilization (NPK) on combined high temperature and ozone damage in rice

BackgroundIncreasing concern has recently been highlighted regarding crop damage due to extreme weather events caused by global warming and the increased production of ground-level ozone. Several studies have investigated rice growth in response to fertilization conditions under various environmental stress conditions; however, studies on growth development in response to fertilization conditions under combined high-temperature/ozone treatment conditions are scarce. In this study, we aimed investigate the growth and physiological development of rice under combined high temperature and ozone treatment conditions and to reveal the damage-mitigation effects of NPK fertilization treatments.ResultsThe plants were treated with varying levels of NPK [N2 (N-P-K: 9.0-4.5-4.0 kg/a), P2 (4.5-9.0-4.0 kg/a), K2 (4.5-4.5-8.0 kg/a), and control (4.5-4.5-4.0 kg/10a).] under combined high-temperature (35 ℃) and ozone (150 pb) treatment conditions. Analysis of the growth metrics, including plant height, leaf age, dry weight, and the plant height/leaf age (PH/L) ratio were revealed that combined high-temperature/ozone treatment promoted the phenological development indicated by increasing leaf age but decreased the plant height and dry weight indicating its negative effect on quantitative growth. The effects of this combined high-temperature/ozone treatment on growth were alleviated by NPK fertilization, particularly in K2 treatment but worsened in N2 treatment. Visible damage symptoms in rice leaves induced by exposure to the combined stressors was also alleviated by the K2 treatment. At the physiological level, K2 treatment reduced the expression of OsF3H2, which is associated with antioxidant activity, suggesting that potassium improved stress tolerance. Additionally, expression of genes related to abscisic acid (ABA) metabolism showed increased OsNECD (ABA synthesis) and decreased OsCYP707A3 (ABA degradation) in the K2 treatment, promoting a stronger adaptive stress response. Stomatal conductance measurements indicated a slight increase under K2 treatment, reflecting enhanced regulation of stomatal function during stress.ConclusionThe study highlights the potential of potassium fertilization to mitigate combined high-temperature and ozone stress in rice, suggesting it as a strategy to improve crop resilience and optimize fertilization. The findings offer insights into fertilization treatments and can guide future research on stress tolerance in crops.

Analysis of Differential Alternative Splicing in Largemouth Bass After High Temperature Exposure.

Temperature is one of the critical factors affecting the physiological functions of fish. With ongoing global warming, changes in water temperature have a profound impact on fish species. Alternative splicing, being a significant mechanism for gene expression regulation, facilitates fish to adapt and thrive in dynamic and varied aquatic environments. Our study used transcriptome sequencing to analyze alternative splicing in largemouth bass gills at 34 °C for 24 h. The findings indicated an increase in both alternative splicing events and alternative splicing genes after high temperature treatment. Specifically, the comparative analysis revealed a total of 674 differential alternative splicing events and 517 differential alternative splicing genes. Enrichment analysis of differential alternative splicing genes revealed significant associations with various gene ontology (GO) terms and KEGG pathways, particularly in immune-related pathways like necroptosis, apoptosis, and the C-type lectin receptor signaling pathway. These results emphasize that some RNA splicing-related genes are involved in the response of largemouth bass to high temperatures.

Rising temperatures may increase fungal epizootics in northern populations of the invasive spongy moth in North America

Insect pest species are generally expected to become more destructive with climate change because of factors such as weakened host tree defences during droughts and increased voltinism under rising temperatures; however, responses will vary by species due to a variety of factors, including altered interactions with their natural enemies. Entomopathogens are a substantial source of mortality in insects, but the likelihood of epizootics can depend strongly on climatic conditions. Previous research indicates that rates of infection of the spongy moth (Lymantria dispar) by its host-specific fungal pathogen, Entomophaga maimaiga, increase with environmental moisture and decrease as temperatures rise. High temperatures may have direct and indirect (due to the associated drying) effects on the fungus, but the interactive effects between temperature and moisture level on larval infection are unclear. Here, we test the hypothesis that warmer, drier conditions will decrease rates of infection of spongy moth larvae by E. maimaiga. We evaluated the effects of precipitation and temperature on larval mortality caused by E. maimaiga with a manipulative field experiment, conducted in one of the northernmost and coldest parts of the spongy moth’s non-native range in North America. We caged laboratory-reared spongy moth larvae in experimentally warmed open-air forest plots, exposing the larvae to soil inoculated with E. maimaiga resting spores during two consecutive trials. Caged larvae were exposed to three temperature treatments — ambient, 1.7 °C above ambient and 3.4 °C above ambient — and either supplemental precipitation (+173 mm per trial) or ambient precipitation. Opposite to our hypothesis, there was no significant effect of supplemental precipitation, nor an interaction between precipitation and temperature. There was, however, a significant positive effect of increasing temperature on the number of larvae infected. On average, in each respective trial, larval infection increased by 44% and 50% under the elevated temperature treatments compared to ambient temperature. Experimental warming may have increased infections because ambient temperatures at the field site were suboptimal for fungal germination. The results from this experiment suggest that, in colder portions of the spongy moth’s invasive range, increasing temperatures due to climate change may enhance the ability of E. maimaiga to help control populations of the spongy moth.

Larval growth rate is not a major determinant of adult wing shape and eyespot size in the seasonally polyphenic butterfly Melanitis leda.

Insects often show adaptive phenotypic plasticity where environmental cues during early stages are used to produce a phenotype that matches the environment experienced by adults. Many tropical satyrine butterflies (Nymphalidae: Satyrinae) are seasonally polyphenic and produce distinct wet- and dry-season form adults, providing tight environment-phenotype matching in seasonal environments. In studied Mycalesina butterflies, dry-season forms can be induced in the laboratory by growing larvae at low temperatures or on poor food quality. Since both these factors also tend to reduce larval growth rate, larval growth rate may be an internal cue that translates the environmental cues into the expression of phenotypes. If this is the case, we predict that slower-growing larvae would be more likely to develop a dry-season phenotype. We performed the first experimental study on seasonal polyphenism of a butterfly in the tribe Melanitini. We measured both larval growth rate and adult phenotype (eyespot size and wing shape) of common evening brown butterflies (Melanitis leda), reared at various temperatures and on various host-plant species. We constructed provisional reaction norms, and tested the hypothesis that growth rate mediates between external cues and adult phenotype. Reaction norms were similar to those found in Mycalesina butterflies. We found that both among and within treatments, larvae with lower growth rates (low temperature, particular host plants) were more likely to develop dry-season phenotypes (small eyespots, falcate wing tips). However, among temperature treatments, similar growth rates could lead to very different wing phenotypes, and within treatments the relationships were weak. Moreover, males and females responded differently, and eyespot size and wing shape were not strongly correlated with each other. Overall, larval growth rate seems to be weakly related to eyespot size and wing shape, indicating that seasonal plasticity in M. leda is primarily mediated by other mechanisms.

Persistence evaluation of fecal pollution indicators in dewatered sludge and dewatering filtrate of municipal sewage sludge: The impacts of ambient temperature and conditioning treatments

Sludge resource utilization is one of the important routines for transmitting fecal pollution to water and soil, and sludge dewatering is a crucial step for sludge resource utilization. However, it remains unclear the decay characteristics and persistence of fecal pollution indicators after sludge dewatering. In this study, the persistence of six fecal pollution indicators, namely E. coli (EC), human-specific HF183 Bacteroides (HF183), human adenovirus (HAdV), human JC and BK polyomavirus (JCPyV and BKPyV), and crAssphage, in dewatered sludge cake and dewatering filtrate deriving from raw sewage sludge, as well as three types of sludge conditioned with polyacrylamide (PAM), Fenton's reagent, or Fe[III] and CaO were analyzed. The quantitative polymerase chain reaction (qPCR) and viability-qPCR methods were used to analyze the variation in abundances and infectivity of fecal pollution indicators in dewatered sludge cake or dewatering filtrate over the storage time, respectively. Decay predications of fecal pollution indicators over time were modeled using either the first-order or the biphasic decay model. The qPCR results revealed that fecal pollution indicators in dewatered sludge cake persisted longer than those in dewatering filtrate at the same temperature. Increasing temperature can accelerate the decay of fecal pollution indicators in both dewatered sludge cake and dewatering filtrate. Notably, sludge conditioning treatment may prolong the persistence of fecal pollution indicators in both dewatered sludge cake and dewatering filtrate. Viability-qPCR results indicated that the fecal pollution indicators (except HAdV) in dewatered sludge cakes deriving from both raw sewage sludge and conditioned sludges remained infectious for up to 30 days. After a storage period of 40 days, the abundances of fecal pollution indicators (except for EC) in sludge conditioned with Fenton's reagent were effectively decreased and meanwhile the infectivity of EC was reduced, exhibiting the lowest levels of fecal pollution. Therefore, both ambient temperature and conditioning treatment greatly impacted the decay characteristics and persistence of fecal pollution indicators in dewatered sludge cake and dewatering filtrate, and selecting suitable conditioning method can minimize environmental risks associated with fecal pollution in sewage sludge.

Engineering of in-plane SnS2–SnO2 nanosheets heterostructures for enhanced H2S sensing

In-plane heterostructures has attracted considerable interest due to exceptional electron transport properties, high specific surface area, and abundant active sites. However, synthesis of in-plane SnS2–SnO2 heterostructures are rarely reported, and the deep investigation of the fine structure on reactivity is of great significance. Here, we propose partial in-situ oxidation strategy to construct the in-plane SnS2–SnO2 heterostructures and the surface properties, the ratio of two components can be finely tuned by precisely adjusting the treatment temperature. In particular, the SnS2–SnO2 heterostructures formed after annealing of SnS2 nanosheets at 350 °C exhibits a unique electronic structure and surface properties due to rich grain boundaries, which exhibits excellent gas sensing performance to H2S (Ra/Rg = 169.81 for 5 ppm H2S at 160 °C, fast response and recovery dynamic (41/101 s), excellent reliability (σ = 0.01) and sensing stability (φ = 0.11 %)). Notably, the in-plane heterostructures endow the material with abundant grain boundaries and effectively regulates the electronic structure of the Sn p-orbital, which facilitate the formation of active oxygen species (O−(ad)), thus contributing to the sensing performance. Our work provides a promising platform to design in-plane heterostructures for various advanced applications.

Dissolution of Primary Carbides and Formation and Healing of Kirkendall Voids in Bearing Steel under Pulsed Electric Current

The alloying elements in 8Cr4Mo4V bearing steel tend to form large primary carbides with carbon, which not only causes element segregation but also becomes the primary source of fatigue crack initiation, thereby decreasing the material's usability and machinability. Owing to the excellent thermal stability of primary carbides, traditional homogenization annealing requires high temperatures, which is both time‐ and energy‐intensive. Excessively high heat treatment temperatures can also result in “overburning” of the sample. Herein, primary carbides are rapidly dissolved at low temperatures using pulsed electric current treatment. The additional free energy introduced by the pulsed electric current lowers the thermodynamic barrier for carbide dissolution. During the second‐phase dissolution process, the unbalanced diffusion of elements may cause the formation of Kirkendall voids. Due to the difference in electrical conductivity between the voids and the matrix, the pulsed electric current generates thermal compressive stress on the voids, promoting rapid atom migration to these voids and accelerating their healing. This pulse‐current treatment technology offers a novel method for the rapid dissolution of carbides in alloys at low temperatures and for the rapid healing of related voids.

An Overview of Biochar Utilization Strategies for Screen-Printed Electrochemical Sensors

In this review, we address the utilization of biochar, a cost-effective material derived from renewable resources (biomass), for the construction of printable electrochemical devices. Key parameters influencing the final properties of biochar, including pyrolysis temperature, pyrolysis duration, heating rate, and activation treatments, are detailed. The role of biochar in the fabrication of electrochemical (bio)sensors is highlighted with emphasis on advancements in screen-printed electrochemical devices. Furthermore, this review showcases examples of using biochar in the construction of portable and flexible screen-printed electrodes, as well as humidity sensors. Future perspectives and challenges in the field of biochar-based electrochemical sensors and biosensors are also discussed, providing a comprehensive outlook on this promising area of research.