Optimum Temperature Research Articles

Sintering trials and microstructural changes mechanism of analogues of americium oxides for radioisotope power systems

Radioisotope thermoelectric generators (RTGs) are deal energy supply devices for deep space and deep-sea exploration, and it is also the energy core of the operation of the working equipment. Except for 238Pu (Plutonium), 241Am (Americium) was also used as a nuclide in the radioactive energy system for future space exploration missions. In this work, neodymium oxide (Nd2O3) was used as analogues for Am2O3. Cold-press-and-sinter methods was used. Different particle parameters (morphology, size, and crystal structure) and synthesized parameters of Nd2O3 were investigated. The synthesized powders contained lath-shaped particles, and batches with different particle sizes and microscopic topography were made and sintered. The results show that the optimal precipitation temperature of Nd2O3 is 25 °C. The optimal thermal decomposition temperature range is 900 °C to 1100 °C, and the optimal thermal decomposition heating rate is 10 °C min−1. The samples of Nd2O3 pellets without cracking is obtained with relative density of 85%–90 %. The Vickers hardness of Nd2O3 pellets was also studied. This paper provides an important scientific guiding significance for the cold-press-and-sinter of radioisotope 241Am batteries in the future.

High-precision temperature control of helium Joule–Thomson cryocooler: Long-term temperature stability

To meet the refrigeration requirements of scientific instruments for mK-level temperature stability over a long-time range in the liquid helium temperature, the temperature characteristics and high-precision control strategies of the helium Joule-Thomson cryocooler (JTC) have been experimentally investigated for the first time. Based on the Ideal Gas Law, the influencing mechanism of pre-cooling temperature, gas reservoir volume, and liquid phase volume fraction on refrigeration temperature were qualitatively analyzed and experimentally verified. An active control studies of pre-cooling temperature, low-pressure and heat load were carried out to verify the feasibility of active temperature control of helium JTC. Finally, a long-term temperature stability of ±1 mK/h was successfully achieved when a multi-stage active control strategy was adopted, which is the optimal long-term temperature stability of helium JTC that have been reported to date.

Exploring bonding temperature variations in diffusion brazing of B4C ceramics with Ni-Cr-Si-Fe-B interlayer: Mechanical and microstructural analysis

This study examines the impact of the bonding temperature parameter on the quality of diffusion brazing joints of B4C ceramics using a Ni-Cr-Si-Fe-B interlayer. Various factors including shear strength, hardness, microstructure, interfacial phenomena, elemental diffusion patterns, formed compounds and phases, and fracture surfaces of the samples were analyzed and compared. The brazed sample at 1110 °C for 1/2 h exhibited the highest shear strength of 62 MPa. Increase of the bonding temperature to the optimum level (1090–1110 °C) enhances the fluidity of the molten interlayer, facilitating its diffusion into the porosities of the ceramic components. This increase also promotes higher interactions within the system, creating favorable conditions for element diffusion. However, surpassing the optimum temperature (1110–1130 °C) may lead to increased destructive reactions and intensify the impact of the coefficient of thermal expansion (CTE) mismatch, resulting in residual stresses and a subsequent decrease in bond strength. The excessive increase in the bonding temperature (1130–1150 °C) can lead to the excessive fluidity of the molten interlayer, potentially causing effusion onto the joint's fixture and damaging the samples. The results indicate the formation of various compounds between the elements of the interlayer and carbon and boron elements, including SiC, Ni4B3, CrB2, Fe2B, Ni6Si2B, and B2Fe3Ni3, at the fracture surface of the sample bonded at 1110 °C. The more substantial peaks of these compounds, compared to other samples, could be a reason for the higher strength of this particular sample.

Impact of Ag2O on the gas sensing properties of the star-shaped BaTiO3/ZnO heterostructures

In this work, star-shaped heterostructures of Ag2O/BaTiO3/ZnO were proposed as resistive-type gas sensors. Through combined analyzes of XRD, SEM, and EDS, the structure, surface morphology, and the elemental composition of the synthesized materials were confirmed. The star-shaped morphology of BaTiO3/ZnO was found to be intact even after loading with different quantities of Ag2O, as revealed by the SEM analysis. The impact of loading different amounts of Ag2O (ranging from 1 % to 3 %) on the sensors' ability to detect volatile organic compounds (VOCs) and carbon dioxide (CO2) was concretely gauged by their response, response/recovery times, selectivity, and long-term stability. For the detection of ethanol/acetone, CO2, and methanol, a 1:2 M ratio of BaTiO3/ZnO with 1 % and 2 % Ag2O, and a 1:3 M ratio of BaTiO3/ZnO with 1 % Ag2O were determined as the optimum content, respectively. From the gas sensing analysis, Ag2O/BaTiO3/ZnO sensors with different amounts of Ag2O additive gave different optimal temperatures for different target gases. Lower operating temperatures, i.e. 180 °C, and 260 °C for CO2 and VOCs, respectively, rapid responsivity with a response time of <1 s for VOCs, and fast recovery times (as low as 10, 13, and 6 s for ethanol, acetone, and methanol vapors, respectively) were observed. More importantly, the sensor exhibited good selectivity for several possible interferences. The underlying reasons for the acceleration of the gas molecules adsorption, hence the fast sensor response, are the high specific surface area established by the star-shaped morphology, and compatible energy band alignment at the p/n interface coupled with the catalytic effect induced by Ag2O.

The effect of developmental temperature on olfaction in a moth revealed by its interaction with body mass

There is a growing interest in the effects of climate warming on olfaction, as temperature may affect this essential sense. In insects, the response of the olfactory system to developmental temperature might be mediated by body size or mass because body size and mass are negatively affected by developmental temperature in most ectotherms. We tested this hypothesis of a mass-mediated effect of developmental temperature on olfaction in the moth Spodoptera littoralis. We measured the olfactory sensitivity of male to female sex pheromone and five plant odors using electroantennography. We compared males reared at an optimal temperature (25 °C with a daily fluctuation of ±5 °C) and at a high temperature (33 ± 5 °C) close to the upper limit of S. littoralis. On average, the olfactory sensitivity of males did not differ between the two developmental temperatures. However, our analyses revealed an interaction between the effects of developmental temperature and body mass on the detection of the six chemicals tested. This interaction is explained by a positive relationship between antennal sensitivity and body mass observed only with the high developmental temperature. Our results show that the effect of developmental temperature may not be detected when organism size is ignored.

Thermophilic Hemicellulases Secreted by Microbial Consortia Selected from an Anaerobic Digester.

The rise of agro-industrial activities over recent decades has exponentially increased lignocellulose biomasses (LCB) production. LCB serves as a cost-effective source for fermentable sugars and other renewable chemicals. This study explores the use of microbial consortia, particularly thermophilic consortia, for LCB deconstruction. Thermophiles produce stable enzymes that retain activity under industrial conditions, presenting a promising approach for LCB conversion. This research focused on two microbial consortia (i.e., microbiomes) that were analyzed for enzyme production using a cheap medium, i.e., a mixture of spent mushroom substrate (SMS) and digestate. The secreted xylanolytic enzymes were characterized in terms of temperature and pH optima, thermal stability, and hydrolysis products from LCB-derived polysaccharides. These enzymes showed optimal activity aligning with common biorefinery conditions and outperformed a formulated enzyme mixture in thermostability tests in the digestate. Phylogenetic and genomic analyses highlighted the genetic diversity and metabolic potential of these microbiomes. Bacillus licheniformis was identified as a key species, with two distinct strains contributing to enzyme production. The presence of specific glycoside hydrolases involved in the cellulose and hemicellulose degradation underscores these consortia's capacity for efficient LCB conversion. These findings highlight the potential of thermophilic microbiomes, isolated from an industrial environment, as a robust source of robust enzymes, paving the way for more sustainable and cost-effective bioconversion processes in biofuel and biochemical production and other biotechnological applications.

Isolation and characterization of a multidrug-resistant Staphylococcus aureus infecting phage and its therapeutic use in mice.

In recent years, the emergence of multidrug-resistant bacteria has limited the selection of drugs for treating bacterial infections, reduced clinical efficacy, and increased treatment costs and mortality. It is urgent to find alternative antibiotics. In order to explore a new method for controlling methicillin-resistant Staphylococcus aureus (S. aureus), this study isolated and purified a multidrug-resistant S. aureus broad-spectrum phage JPL-50 from wastewater. JPL-50 belongs to the Siphoviridae family after morphological observation, biological characterization, and transmission electron microscopy (TEM) fragmentation spectrum analysis. It can cleave 84% of tested S. aureus (168/200), in which 100% of tested mastitis-associated strains (48/48) and 72.04% of MRSA strains (67/93) were lysed. In addition, it has an optimal growth temperature of about 30°C, a high activity within a wide pH range (pH 3-10), and an optimal multiplicity of infection of 0.01. The one-step growth curve shows a latent time of 20 min, an explosive time of 80 min. JPL-50 was 16 927bp in length and was encoded by double-stranded DNA, with no genes associated with bacterial resistance or virulence factors detected. In a therapeutic study, injection of the phage JPL-50 once and for 7 times in 7 days protected 40% and 60% of the mice from fatal S. aureus infection, respectively. More importantly, JPL-50-doxycycline combination could effectively inhibit host S. aureus in vitro and reduce the use of doxycycline within 8 h. In conclusion, the bacteriophage JPL-50 has a wide lysis spectrum, high lysis rate, high tolerance to extreme environments, and moderate in vivo activity, providing ideas for developing multidrug-resistant S. aureus infections.

Off-design performance optimization for steam-water dual heat source ORC systems

High-pressure steam and hot water often coexist as industrial waste heat. In this study, dual loop and single loop ORC systems are designed for 700 kPa, 4.1 kg/s steam, and 90 ℃, 122.36 kg/s hot water conditions to study the off-design performance when steam or hot water conditions change. To maximize net output power, we employ a particle swarm optimization algorithm to optimize the evaporation and condensation temperatures. The results show that within the specified hot water conditions, the evaporation and condensation temperatures of D-ORC's low-pressure loop and S-ORC increase with rising hot water inlet temperature and flow rate. The S-ORC demonstrates a higher net output power growth rate as hot water flow rate and temperature rise. Under specific steam conditions, when the steam outlet is in a gas-liquid two-phase state, D-ORC's maximum net output power is 1.7 % higher than that of the S-ORC, with little variation in optimal evaporation and condensation temperatures with respect to steam inlet pressure. At a 3.5 kg/s steam flow rate, the D-ORC's high-pressure loop becomes ineffective, whereas S-ORC efficiently adjusts heat exchange capacity under diverse steam-water conditions, Consequently, the D-ORC's average net output power is 34.2 % lower than that of the S-ORC.

Temperature dependent cholinergic synapse induced by triphenyl phosphate and tris(1.3-dichloroisopropyl) phosphate via thyroid hormone synthesis in Cyprinus carpio

Triphenyl phosphate (TPHP) and tris(1.3-dichloroisopropyl) phosphate (TDCIPP) are emerging contaminants that pervade diverse ecosystems and impair the thyroid and neural signaling pathways. The intricate interactions between thyroid and neurodevelopmental effects mediated by TPHP and TDCIPP remain elusive. This study integrates in vivo, in vitro, and in silico approaches to elucidate these mechanisms in Cyprinus carpio at varying temperatures. It showed that TPHP and TDCIPP hindered fish growth, particularly at low temperatures, by interfering with thyroid hormone synthesis and transport processes. Both compounds have been identified as environmental hormones that mimic thyroid hormone activity and potentially inhibit acetylcholinesterase, leading to neurodevelopmental disorders characterized by brain tissue damage and disrupted cholinergic synapses, such as axon guidance and regeneration. Notably, the bioaccumulation of TPHP was 881.54 % higher than that of TDCIPP, exhibiting temperature-dependent variations with higher levels of TDCIPP at low temperatures (20.50 % and 250.84 % above optimum and high temperatures, respectively), suggesting that temperature could exacerbate the toxicity effects of OPEs. This study sheds new light on the mechanisms underlying thyroid endocrine disruption and neurodevelopmental toxicity in C. carpio. More importantly, these findings indicate that temperature affects the environmental fate and effects of TPHP and TDCIPP, which could provide an important basis for ecological environmental zoning control of emerging contaminants in the future.

Boriding of Ti-xNb alloys: Influence of Nb on the features of boride layer

In this study, Ti-xNb (x = 0–40 wt%) alloys produced by the powder metallurgy were borided with the aim of clarifying the effect of Nb on the structural and mechanical properties of the boride layer. After smearing the paste prepared from nano boron powder on the surfaces of the alloys, boriding was conducted at three different temperatures (900, 1000 and 1100 °C) for 8 h in a vacuum atmosphere. Unlike those formed at 900 °C, boriding temperatures of 1000 and 1100 °C provided thicker and homogenous boride layers. However, the boriding temperature of 1100 °C induced cracking within the boride layer of the Ti40Nb alloy. For these reasons, the optimum boriding temperature was determined as 1000 °C. Increase in the Nb content not only increased the fraction of β-Ti phase in the microstructure of the sintered alloy at the expense of α-Ti, but also induced NbB2 in the structure of the boride layer along with TiB2. While Nb-poor α-Ti grains favoured the growth of TiB2, TiB2·NbB2 mixture preferentially developed over the Nb-rich β-Ti grains. As the result of this, the hardness of the boride layer tended to decrease with increasing Nb content of the substrate. For example, the average hardness of the boride layers formed on Nb-free Ti and Ti40Nb alloy were measured as ∼2674 HV0.025 and ∼ 2460 HV0.025, respectively. But regardless from the hardness, the boride layers provided a good protection for the underlying substrates against dry sliding contact and triggered abrasive wear on the contact surface of the counterface (WC-Co ball). The presence of NbB2 in the boride layer led to a reduction in abrasive wear of the counterface. This finding revealed that in any wear-related application, where borided Ti alloys were intended to be used, it is better to choose high Nb-containing Ti alloys instead of α-Ti to minimize the wear of the tribo-couple via reducing the abrasion at the counter body.

Comparative genomic analysis of thermophilic fungi reveals convergent evolutionary adaptations and gene losses

Thermophily is a trait scattered across the fungal tree of life, with its highest prevalence within three fungal families (Chaetomiaceae, Thermoascaceae, and Trichocomaceae), as well as some members of the phylum Mucoromycota. We examined 37 thermophilic and thermotolerant species and 42 mesophilic species for this study and identified thermophily as the ancestral state of all three prominent families of thermophilic fungi. Thermophilic fungal genomes were found to encode various thermostable enzymes, including carbohydrate-active enzymes such as endoxylanases, which are useful for many industrial applications. At the same time, the overall gene counts, especially in gene families responsible for microbial defense such as secondary metabolism, are reduced in thermophiles compared to mesophiles. We also found a reduction in the core genome size of thermophiles in both the Chaetomiaceae family and the Eurotiomycetes class. The Gene Ontology terms lost in thermophilic fungi include primary metabolism, transporters, UV response, and O-methyltransferases. Comparative genomics analysis also revealed higher GC content in the third base of codons (GC3) and a lower effective number of codons in fungal thermophiles than in both thermotolerant and mesophilic fungi. Furthermore, using the Support Vector Machine classifier, we identified several Pfam domains capable of discriminating between genomes of thermophiles and mesophiles with 94% accuracy. Using AlphaFold2 to predict protein structures of endoxylanases (GH10), we built a similarity network based on the structures. We found that the number of disulfide bonds appears important for protein structure, and the network clusters based on protein structures correlate with the optimal activity temperature. Thus, comparative genomics offers new insights into the biology, adaptation, and evolutionary history of thermophilic fungi while providing a parts list for bioengineering applications.

Identification of a transglutaminase from Bacillus amyloliquefaciens: Gene mining, protein expression, mechanism analysis and enzymatic characterization

Transglutaminase (TGase) can catalyze the crosslinking within or between protein molecules, improving the structural and functional properties of proteins. It has been widely used in artificial meat, yogurt products, flour products and other foods. In this study, a high yield TGase strain was screened from fermented soybean, and it was identified as the Bacillus amyloliquefaciens XCT-09. Then, the transglutaminase (X9Tgl) from XCT-09 was expressed in Escherichia coli BL21(DE3), and the enzyme activity of purified X9Tgl reached 5.73 U/mg. Subsequently, the catalytic mechanism of X9Tgl was elucidated, and the X9Tgl contained the active center of E115, C116 and E187, as well as the substrate binding sites W149 and F69. Furthermore, this study characterized the enzymatic properties of X9Tgl, and the optimal catalytic temperature and pH were 60 °C and 6, respectively. Moreover, X9Tgl exhibited stronger thermal stability and pH tolerance than STG, and it was not inhibited by the majority of metal ions. This study successfully identified a X9Tgl with high thermal stability, and pH tolerance, which provided a potential TGase resource for application in the food and medicine fields.

Heat pipe for thermally coupled fuel cell and metal hydride as well as for cooling metal hydride hydrogen charging

ABSTRACT In this paper, a metal hydride (MH) canister and a PEM fuel cell are coupled using heat pipes to study the minimum number of heat pipes required, the operating range of the fuel cell, and the temperature change patterns of the MH. We account for temperature difference limitations between the fuel cell and the MH (∆T = 35–55 K) on the heat pipe dynamics, which has been neglected in previous similar studies. Since the hydrogen absorption rate of the MH canisters exhibits an initial increase followed by a decrease with increasing temperature, an analysis was conducted to select the appropriate heat pipe under different hydrogen filling pressures. This analysis ensured that the MH canisters remained at the optimal charging temperature (326 K) and achieved the maximum charging rate (6.64 slpm).

A model fitting approach for the investigation of thermo-kinetic parameters of rice straw: a viable renewable energy resources in Bangladesh

This study investigates the potential of renewable energy sources to address the growing energy demands of developing nations while ensuring environmental sustainability. Here, a model-based analysis to assess the feasibility of utilizing rice straw pyrolysis as a renewable energy source is investigated. The thermogravimetric analysis identified the optimal temperature range for pyrolysis (230–400 °C) and the Coats–Redfern model was employed for kinetic analysis. Diffusion models, particularly D3, exhibited the best fit with an activation energy of 16–18 kJ/mol. Thermodynamic analysis confirmed the endothermic nature of the process, with positive enthalpy and negative entropy changes indicating an increase in energy and a more ordered product. These findings suggest that rice straw pyrolysis holds promise as a viable renewable energy option. This study contributes to understanding the rice straw pyrolysis mechanism which could be helpful for its effective utilization at commercial scale.

Heavy metals altered the xenobiotic metabolism of rats by targeting the GST enzyme: An in vitro and in silico study

Among all the heavy metals, Pb, Cd, and As are the most harmful pollutants in the environment. They reach into the organisms via various levels of food chains i.e. air and water. Glutathione-s-transferase (GST, E.C. 2.5.1.18), a key enzyme of xenobiotics metabolism, plays an important role in the removal of several toxicants. The present study aimed to evaluate any inhibitory action of these heavy metals on the GST enzyme isolated from the hepatic tissues of rats. A 10 % (w/v) homogenate of rat liver was prepared in cold and centrifuged at 4 °C at 9000xg for 30 min. The supernatant was collected and kept frozen at −20 °C or used fresh for carrying out different experiments. The activity of GST was monitored spectrophotometrically at 340 nm using 220 μg of soluble protein with varying equal substrate concentrations (0.125–2 mM) in phosphate buffer (50 mM, pH 6.5). To assess the impact of heavy metals on the enzyme activity, different concentrations of Cd (0–0.6 mM) and Pb (0–2 mM) were added to the reaction mixture followed by monitoring the residual activity. The optimum temperature and pH of rat liver GST were found to be 37 °C and 6.5, respectively. The Km value for GST was 0.69 mM and the Vmax was found to be 78.67 U/mg. The Cd and Pb significantly altered the kinetic behaviour of the enzyme. The Vmax and Kcat/Km parameters of GST were recorded to be decreased after interaction with Cd and Pb individually and showed a mixed type of inhibition pattern suggesting that these inhibitors may have a greater binding affinity either for the free enzyme or the substrate-enzyme complex. These metals showed a time-dependent enzyme inhibition profile. Cd was found to be the most potent inhibitor when compared to other treated metals; the order of inhibitory effect of metal ions was Cd>Pb>As. The in silico ion docking analysis for determining the probable interactions of Cd and Pb with fragmented GST validated that Cd exhibited higher inhibition potential for the enzyme as compared to Pb. The results of the present study indicated that exposure of both the Cd and Pb may cause significant inhibition of hepatic GST; the former with higher inhibitory potential than the later. However, As proved to be least effective against the enzyme under the aforesaid experimental conditions.

One-step fabrication of hetero-structured polyethersulfone hollow fiber membranes through surface segregation for pervaporation desalination

Hollow fiber membranes (HFMs) are an ideal configuration for industrial applications of pervaporation desalination (PV) membranes. Currently, the efficient fabrication of PV HFMs is restricted by multi-step post-treatment processes on their outer surfaces to form the selective layer. Herein, we utilized the surface segregation strategy to fabricate a hetero-structured HFM in one step, simultaneously forming the hydrophilic dense outer layer and the porous support layer. During hollow fiber spinning process, the amphiphilic copolymer polyvinylpyrrolidone-polyvinyl acetate (PVP-PVAc) in polyether sulfone (PES) dope solution migrated towards water contacting interface in the coagulation bath and formed the hydrophilic layer by extending hydrophilic segment outwards. This fast in-situ hydrophilization well matched the spinning efficiency. The optimal PVP-PVAc content and phase inversion temperature were investigated and the spinning parameters on the structure and performance of HFMs were studied. The HFMs prepared realized a flux of 26.70 kg m−2 h−1 and the salt rejection of 99.98 %, along with adaptability to solutions with different salinities and excellent anti-organic fouling property. This study may provide a facile method to fabricate HFMs with desirable PV desalination performance and scaling-up potential.

Molecular Dynamics Simulation and Experimental Study of the Mechanical and Tribological Properties of GNS-COOH/PEEK/PTFE Composites.

Molecular dynamics (MD) simulations were first employed to achieve the optimal sintering temperature of carboxyl-functionalized graphene (GNS-COOH)-modified polyether ether ketone (PEEK)/polytetrafluoroethylene (PTFE) composites. A model of GNS-COOH/PEEK/PTFE composites was constructed to simulate the effects of different sintering temperatures on the mechanical and tribological properties, as well as their underlying atomic mechanisms. Samples of PTFE composites were prepared and characterized through experimental methods. Results revealed that the sintering temperature significantly affects the intermolecular forces, mechanical properties, and tribological characteristics of the composites. The agglomeration of the PEEK/PTFE composite matrix was effectively mitigated by introducing GNS-COOH. When the sintering temperature was controlled at 360 °C, the compressive strength of GNS-COOH/PEEK/PTFE composites was improved compared to GNS/PEEK/PTFE composites, albeit with a slight reduction in wear resistance. This study provides a theoretical reference for the preparation process and performance evaluation of new materials.

Components optimization of polyurethane-modified asphalt binder towards compatibility: Insight from molecular dynamics simulations

Polyurethane-modified asphalt demonstrated the enhanced durability and skid resistance, while remaining the drawback in the compatibility between the polyurethane modifier and asphalt binder in practical use. Herein, a molecular-dynamics-simulations based compatibility evaluation method is proposed for the polyurethane modifier and asphalt binder, thereby achieving the cost-effective and efficient components optimization. Twelve components asphalt molecular model was built in Molecular Dynamics to investigate the interaction of asphalt binder to the polypropylene glycol, toluene diisocyanate, and diphenylmethane diisocyanate, respectively. The molecular model of polyurethane modified asphalt binder was verified by the similar loss modulus temperature from the simulation and temperature scanning tests. The simulation outcomes indicate significant variations in the compatibility of different polyurethanes with asphalt, in which diphenylmethane diisocyanate-type polyurethane exhibits the superior compatibility. The compatibility of various polyurethane concentrations in asphalt shows considerable disparity, suggesting that the compatibility index can serve as a criterion for determining the optimal dosage of the modifier. Temperature also exerts an influence on the compatibility of polyurethane modified asphalt binder. Simulation results indicates that 130 °C potentially may be the optimal temperature for its preparation, which is corroborated by the microscopic characterization. This study provides a fundamental framework for the molecular dynamics simulation-based components optimization of polyurethane-modified asphalt, thereby inspiring the targeted design of asphalt materials.

Integrating artificial intelligence for optimal thermal comfort: A design approach for electric heating textiles aligned with user preferences

Human thermal comfort, crucial for well-being and productivity, is often improved by personal comfort systems that offer tailored control over environmental conditions while promoting energy efficiency. Previous studies have explored various textile technologies in thermoregulation systems according to user preferences. However, limited research has focused on temperature prediction by artificial intelligence to maximize thermal comfort for varied users. This study proposes a design approach to optimize thermal comfort in electric heating textiles using artificial intelligence, considering user preferences related to age and gender differences. A fuzzy logic model is established as a proof of concept for temperature regulation by varying ambient temperature, followed by developing an artificial neural network model to predict the optimal temperature for maximum comfort. Subsequently, a smart electric heating jacket is fabricated to assess preferred heating temperatures among 50 subjects with varying ages and genders. Results from the artificial neural network model show promising temperature prediction, while subject tests reveal significant differences in skin temperatures based on gender. This emphasizes the need for artificial intelligence-based heating e-textiles to accommodate diverse user needs. The study’s findings are expected to contribute to intelligent temperature regulation in thermal textiles and wearables, benefitting both the industry and consumers through customized heating products.

Ultrasensitive xylene sensor based on RuO2-modified BiVO4 nanosheets

Two-dimensional (2D) BiVO4 nanosheets (NSs), featuring distinctive chemical properties and dangling-bond-rich surfaces, are promising for developing high-performance gas sensors. However, the previously reported 2D BiVO4 NSs-based devices suffer from a low responsivity and poor selectivity. In this work, we introduce RuO2 nanoparticles to boost the gas sensing properties of 2D BiVO4 NSs-based sensor. Intriguingly, the RuO2-decoration changes the selectivity of the corresponding gas sensor from acetone to xylene. Compared to the pristine BiVO4 sensor, the RuO2-BiVO4 sensor displays a reduced optimal operating temperature of 260℃ and exhibits a response of 19.0–5 ppm xylene, reaching a five-fold enhancement. Simultaneously, the RuO2-BiVO4 sensor also exhibits a rapid response and recovery time of 10 and 25 s respectively, as well as robust long-term stability with less than 5 % variation in response after a storage of 60 days. The improvement in sensing performance can be attributed to the RuO2-decoration from three aspects: heterojunction construction, surface state modulation and gas oxidation catalysis on the surface. This work not only provides a high-performance xylene sensing material but also provides insightful comprehension regarding the modification effects of RuO2.