Resistivity Research Articles

Coral-like Ti3C2Tx/PANI Binary Nanocomposite Wearable Enzyme Electrochemical Biosensor for Continuous Monitoring of Human Sweat Glucose

With the continuous advancement of contemporary medical technology, an increasing number of individuals are inclined towards self-monitoring their physiological health information, specifically focusing on monitoring blood glucose levels. However, as an emerging flexible sensing technique, continuous and non-invasive monitoring of glucose in sweat offers a promising alternative to conventional invasive blood tests for measuring blood glucose levels, reducing the risk of infection associated with blood testing. In this study, we fabricated a flexible and wearable electrochemical enzyme sensor based on a two-dimensional Ti3C2Tx MXene nanosheets and coral-like polyaniline (PANI) binary nanocomposite (denoted as Ti3C2Tx/PANI) for continuous, non-invasive, real-time monitoring of sweat glucose. The exceptional conductivity of Ti3C2Tx MXene nanosheets, in conjunction with the mutual doping effect facilitated by coral-like PANI, significantly enhances electrical conductivity and specific surface areas of Ti3C2Tx/PANI. Consequently, the fabricated sensor exhibits remarkable sensitivity (25.16 μA·mM−1·cm−2), a low detection limit of glucose (26 μM), and an extensive detection range (0.05 mM ~ 1.0 mM) in sweat. Due to the dense coral-like structure of Ti3C2Tx/PANI binary nanocomposite, a larger effective area is obtained to offer more active sites for enzyme immobilization and enhancing enzymatic catalytic activity. Moreover, the sensor demonstrates exceptional mechanical performance, enabling a 60° bend in practical applications, thus satisfying the rigorous demands of human sweat detection applications. The results obtained from continuous 60 min in vitro monitoring of sweat glucose levels demonstrate a robust correlation with the data of blood glucose levels collected by a commercial glucose meter. Furthermore, the fabricated Ti3C2Tx/PANI/GOx sensor demonstrated agreement with HPLC findings regarding the actual concentration of added glucose. This study presents an efficient and practical approach for the development of a highly reliable MXene glucose biosensor, enabling stable and long-term monitoring of glucose levels in human sweat.

Conductivity Insights Into the Carbon Nanotubes Mobility Restricted by the Long‐Branched Chains During the Thermal Annealing, Fast Shear Flow and Melt to Solid Cooling Process

AbstractThe present work provides a unique insight to reveal the long chain branching (LCB) influence to the nano‐fillers, that is via analyzing the conductivity evolution during the thermal annealing, fast shear flow and melt to solid cooling process. Meanwhile the crystallization behavior is also discussed. A linear polypropylene (PPC) and a long chain branched polypropylene (PPH) are chosen as the two polymer matrices with carbon nanotubes (CNTs) as the nanofillers. During the thermal annealing process, a more obvious growth of electrical conductivity of linear PPC nanocomposites are observed compared with LCB PPH nanocomposites. The harder movement of CNTs inside LCB PPH matrix may be the main reason. This also can be reflected by the conductivity evolution during slow cooling process where a decrease‐then‐increase (DTI) phenomenon is found for PPC/CNTs systems due to the rebuilding of CNTs conductivity network after crystallization. By contrast, this does not happen for PPH/CNTs systems.

Evaluating the Growth Response of Ricinus communis L. Cultivars to Salt Stress Using a Fast and Reliable Bioassay

AbstractHere is proposed an easy, fast, and economic technique to investigate plant physiological traits in response to salt stress by using castor bean (Ricinus communis L.). Four Ricinus communis L. cultivars (TUNI 1, TUNI 4, C1012, and C1028) were grown in a growth chamber for 15 days on a sand substrate and were watered regularly with deionised water or NaCl solution (water electrical conductivity (EC) 4, or 8 dS m− 1) to keep soil moisture close to field capacity. According to roots, stem, and germination traits and derived indices, TUNI 1 and TUN4 showed the best growth performance on sand irrigated with 4 dS m− 1 and 8 dS m− 1, respectively. Besides, comparing C1028 and C1012, the former showed a higher tolerance at the maximum electrical conductivity tested related to the latter, increasing salt tolerance index (STI) of roots (+ 25%) and stem (+ 20%). In conclusion, the present findings suggest that the TUNI 4 cultivar of Ricinus communis L. demonstrates superior overall performance, even under highly saline conditions, such as irrigation with 8 dS m− 1. Conversely, the TUNI 1 cultivar shows a good ability to perform in marginal soils with moderate salinity levels, such as those irrigated with 4 dS m− 1. Our results represent the first step towards optimization of a cost-effective method/bioassay for the selection of salt tolerant Ricinus communis L. cultivars and genotypes.

Application of GIS for Monitoring Firefly Population Abundance (Pteroptyx tener) and the Influence of Abiotic Factors

This study focuses on the <i>Pteroptyx tener</i> species in the Sepetang River, Malaysia, aiming to evaluate the firefly’s abundance and explore its correlation with various biotic and abiotic parameters. The study was conducted over six months, from November 2021 to April 2022, utilizing Geographic Information System (GIS) software to apply hotspot mapping and Inverse Distance Weighting (IDW) analysis to elucidate the spatial distribution of firefly populations. A total of 111,615 individuals were recorded, with a particular focus on this firefly species’ presence on their display trees. Hotspot analysis showed that Station 6, located at the mouth of a river with dense mangroves, hosted 55,723 fireflies (50.01%). In contrast, Stations 9 and 10, near ponds and shrimp settlements, recorded 517–723 fireflies (0.65% and 0.46%). Pearson’s correlation coefficient (r) unveiled a statistically significant positive correlation (r = 0.88, p < 0.05) between wind speed and the abundance of firefly populations within the Sepetang River. However, no statistically significant correlation (p > 0.05) was found between firefly abundance and various other abiotic parameters, including relative humidity (RH), air temperature, tide level, pH, electrical conductivity (EC), salinity, total dissolved solids (TDS), and water clarity. Thus, the results revealed the preference for fireflies due to the availability of vegetation, wind speed and minimal disturbance in this area. In conclusion, this study’s information significantly adds to our understanding of these interesting insects and their complicated relationships in nature. It underscores the importance of preserving their habitats and ecosystems.

Investigating Enhanced Electrical Conductivity in Ice VII

At ambient conditions, the electrical conductivity of H2O is around 0.01 S/m, whereas in the deep interiors of Neptune and Uranus (≈5000 K and ≈300 GPa), conductivity increases by three orders of magnitude. So far, few experimental studies have considered the conductivity properties of ice at high-P-T conditions. In this work, we evaluate how the conductivity of H2O changes upon compression at 300 K, and show that at 10 GPa, ice VII exhibits a maximum in conductivity of 1.43 ± 0.47 × 10−5 S/m. We propose that time is an important variable in impedance spectroscopy measurements during the pressure-induced transitions: fluid → phase VI → phase VII, between 0.5 and 4 GPa.

Green synthesis of boehmite-reinforced cashew gum/polypyrrole biopolymer blend for advanced biomaterials

Electrically conducting biopolymer blend nanocomposites based on different contents of boehmite (BHM) reinforced cashew gum (CG) /polypyrrole (PPy) blend is synthesized by an in situ polymerization technique using water as a green solvent. The resulting bio-blend nanocomposites underwent comprehensive analysis concerning their structural, morphology, thermal, and electrical properties, such as dielectric constant, dielectric loss, electric modulus, and AC conductivity. The Fourier transform infrared spectroscopy (FTIR) spectra revealed the presence of metal oxide stretching in the blended nanocomposite at 512 cm−1. Field emission scanning electron microscopy (FE-SEM) confirmed the attachment and uniform dispersion of BHM within the CG/PPy blend at 7 wt% loading, and beyond this loading, the nanoparticles get agglomerated in the biopolymer blend. The glass transition temperature and thermal stability of all the blended nanocomposites are higher than that of the pure CG/PPy blend and these thermal properties increase with the loading of nanoparticles. Conductivity experiments demonstrated that as the nanofiller content increases up to 7 wt%, there is a concurrent rise observed in AC conductivity, dielectric loss, and dielectric constant. There is a substantial difference of 1.21 Scm−1 between the maximum and minimum AC electrical conductivity, at 102 Hz. However, a decrease in electrical properties is observed at the highest loadings of BHM due to the agglomeration of nanoparticles in the polymer blend matrix. The lowest activation energy value (0.049 × 10−4 eV) is also exhibited by 7 wt% BHM nanocomposites. Furthermore, the electrical properties of both CG/PPy and CG/PPy/BHM nanocomposites exhibited a temperature-dependent behavior, progressively increasing until reaching maximum values. This study suggests that such bio-based polymer dielectrics could be promising materials for various applications, offering enhanced thermal and electrical properties through careful control of nanofiller content and dispersion.

1-D electrical inversion sensitivity applied to CO2 geological storage monitoring

Discussions on the effects of anthropogenic emissions of greenhouse gas and their consequences on climate change have gained public notoriety in recent decades. The capture of carbon dioxide (CO2) from industrial sources and its subsequent storage in geological reservoirs has the potential to play an important role in reducing the harmful effects of the atmosphere CO2 emissions in the medium and long term. Based on their physical properties for applying geophysical techniques, studying and evaluating the behavior of rocks in the presence of CO2 has shown high relevance. This study deals with monitoring geological reservoirs in the presence of CO2 through the electrical resistivity method to estimate the electrical properties of the rocks involved, such as CO2 saturation and electrical resistivity of the medium. Simulations were performed on a four-layer synthetic model. The results validated the applicability of the electrical method in monitoring CO2 injection and leakage.

Green Synthesis and Enhanced Photocatalytic Performance of rGO/ZnO/Fe3O4 Nanocomposites: A Sustainable Approach to Environmental Remediation.

The fast industrialization and mounting pollution have necessitated the need for advanced materials in order to degrade pollutants efficiently. Metal oxide-based and graphene-derivative photocatalytic nanocomposites are excellent for harnessing light energy in environmental remediation. Among them, ZnO-based nanocomposites have drawn considerable attention because of their high photocatalytic activity and stability. However, improving the performance of these nanocomposites is still necessary for their wide applications. This study explores the green synthesis, detailed characterization, and enhanced photocatalytic efficiency of reduced graphene oxide rGO/ZnO/Fe3O4 nanocomposites. The nanocomposites were synthesized via a hydrothermal method, utilizing milk thistle extract as a natural reducing agent, representing a novel and sustainable approach to fabricating magnetic rGO/Fe3O4 nanocomposites. These composites were further integrated with zinc oxide to produce a multifunctional material, exhibiting high surface area, superior electrical and thermal conductivity, and robust mechanical strength. The photocatalytic performance was significantly enhanced due to the synergistic interaction between graphene and metal oxide nanoparticles, leading to efficient degradation of environmental pollutants. Electrochemical analysis via cyclic voltammetry revealed distinctive redox peaks, demonstrating efficient electron transfer processes essential for applications in energy conversion and storage. This green synthesis not only provides a sustainable pathway for the development of advanced nanocomposites but also underscores their potential in a wide range of applications, including environmental remediation, sensing, energy storage, and optoelectronics.

Experimental and numerical investigations on phase change thermal storage foam concrete based on CaCl2∙6H2O/silica aerogel composite phase change material

A new type of phase change thermal storage foam concrete was developed by effectively incorporating a composite phase change material (CPCM) into foam concrete. The CPCM was obtained by using 75 wt% CaCl2∙6H2O as PCM and 25 wt% silica aerogel as carrier, with a phase change temperature of 27.0 °C and an enthalpy value of 110.9 J/g. The mechanical and thermal properties of the obtained phase change thermal storage foam concrete blocks were investigated experimentally, along with a numerical analysis of their heat transfer characteristics. The experimental results demonstrated that after adding CPCM, the thermal performances of foam concrete blocks significantly increased, under the condition of their dry densities and compressive strengths met the specification requirements. Adding 20 wt% CPCM, the enthalpy value, specific heat capacity, thermal conductivity and thermal inertia of foam concrete block respectively reached 37.0 J/g, 1782.0 J/(kg∙K), 0.131 W/(m·K) and 770.9, with appropriate phase change temperature (27.2 °C). Numerical analysis for the heat transfer characteristics of the phase change thermal storage foam concrete wall revealed that optimal thermal insulation and thermal storage performances were achieved when the wall contained 20 wt% CPCM and thickness of 80 mm. In this case, the model exhibited a temperature wave attenuation factor of 6.66, the temperature amplitude of 5.84 K and a decline of 9.87 K for the highest temperature of the wall as well as delay time of 198,000 s, effectively regulating indoor temperature and saving energy. Therefore, the as-prepared phase change thermal storage foam concrete had great potential for application in building energy conservation.

Regulation of reinforced phases and its influence on the properties of (Ni2B+C)/Cu composite by heat and mechanical treatments

In this paper, (Ni2B+C)/Cu composites were prepared by hot pressing sintering (HP), and then heat treatment (HT) and multidirectional forging (MDF) were carried out to regulate the amount, size and distribution of reinforced phases. The evolution behavior of local structure and its effect on properties during heat treatment and multidirectional forging were studied. Results show that the Vickers hardness and electrical conductivity of (Ni2B+C)/Cu composite after solid solution, multidirectional forging, and aging treatment can reach 171.1 HV and 46.5 %IACS, respectively, which are increased by 55.3 % and 69.1 % compared with the as-sintered. The tensile strength can reach 355.1 MPa, and the facture elongation is increased to 5.2 % compared with the as-sintered (0.3 %), achieving a transition from brittle fracture to plastic fracture. In addition, the dry friction and wear mechanism of the composite is mainly abrasive wear, while the current-carrying friction and wear mechanism changes from abrasive wear to a coexistence of abrasive wear and oxidation wear. This work provides a new way to improve the properties of (Ni2B+C)/Cu composites.

Core-Shell Engineered Fillers Overcome the Electrical-Thermal Conductance Trade-Off.

The rapid development of modern electronic devices increasingly requires thermal management materials with controllable electrical properties, ranging from conductive and dielectric to insulating, to meet the needs of diverse applications. However, highly thermally conductive materials usually have a high electrical conductivity. Intrinsically highly thermally conductive, but electrically insulating materials are still limited to a few kinds of materials. To overcome the electrical-thermal conductance trade-off, here, we report a facile Pechini-based method to prepare multiple core (metal)/shell (metal oxide) engineered fillers, such as aluminum-oxide-coated and beryllium-oxide-coated Ag microspheres. In contrast to the previous in situ growth method which mainly focused on small-sized spheres with specific coating materials, our method combined with ultrafast joule heating treatment is more versatile and robust for varied-sized, especially large-sized core-shell fillers. Through size compounding, the as-synthesized core-shell-filled epoxy composites exhibit high isotropic thermal conductivity (∼3.8 W m-1 K-1) while maintaining high electrical resistivity (∼1012 Ω cm) and good flowability, showing better heat dissipation properties than commercial thermally conductive packaging materials. The successful preparation of these core-shell fillers endows thermally conductive composites with controlled electrical properties for emerging electronic package applications, as demonstrated in circuit board and battery thermal management.

Tuning Supercapacitive Behavior of Eri Silk (Philosamiaricini)‐Polyanilne Nanocomposite for Electrodes Applications

ABSTRACTHerein, the synthesis of Polyaniline‐Eri nanosilk fibroin (PANI/ENSF) composite supercapacitor electrode material by utilizing Eri silk (Philosamiaricini) as a raw material and polyaniline (PANI) with H2SO4 as doping acid and (NH4)2S2O8 as an oxidant, via a simple in situ oxidative polymerization technique, with good performance characteristics is reported. The chemical composition of the composites have been studied by using XRD, FT‐IR, UV–vis spectroscopy, Raman spectroscopy, and morphology is studied by SEM. BET analysis reveals that the surface area of composite is 712.10 m2g−1, and BJH analysis shows that the pore size is mainly concentrated between 1.5 and 15.7 nm. The composite shows electrical conductivity of 17.33 × 10−2 Scm−1 (Keithley Model 2000). The electrochemical performances are evaluated by using CV, GCD, and EIS measurements. The three‐electrode system composite shows specific capacitance of about 310.12 Fg−1 at 0.1 Ag−1, which is the highest value being reported, compared to already available polyaniline‐silk composites. Further the studies have been extended to assemble a symmetrical two‐electrode supercapacitor device which also exhibits a high value of specific capacitance of 35 Fg−1 at 5 Ag−1 and 96.12% capacity retention over 5000 cycles. For the first time, this study reports using a Polyaniline‐Eri nanosilk composite to design an efficient supercapacitor electrode.

Tuning the Electronic And Transport Properties of CaMoO4 Nanofibers with High-Spin Ni for Efficient and Stable Supercapacitors.

Calcium molybdate (CaMoO4) has recently garnered considerable attention for supercapacitors due to its stable crystal structure and cost-effective preparation. However, CaMoO4 prepared by traditional processes still suffered from insufficient electrochemical active sites and poor electrical conductivity so far, thus leading to the performance of CaMoO4-based supercapacitors being inferior to the state-of-the-art ones. CaMoO4 nanofibers with a high specific surface area exhibit great potential for supercapacitors due to their ability to offer increased charge storage. Herein, mesoporous CaMoO4 nanofibers anchored with Ni nanoparticles were fabricated via electrospinning combined with subsequent thermal treatment. Density functional theory calculation and UV-vis spectrophotometer results show that high-spin state Ni nanoparticles can tune the electronic structure of CaMoO4 nanofibers, decreasing the band gap by about 0.67 eV. Electron paramagnetic resonance (EPR) studies imply that Ni doping influences the electronic structure by reducing the oxygen vacancy concentration and introducing hyperfine structures associated with Ni spins. These can result in higher power and energy density in supercapacitors. As a result, a specific capacitance of 1253.7 F·g-1 at a current density of 0.5 A·g-1 and an 86% retention rate after 2000 cycles at a higher current density of 5 A·g-1 have been achieved for Ni0.25Ca0.75MoO4-based supercapacitor. Furthermore, an asymmetric supercapacitor (ASC) device with the optimized CaMoO4/Ni//AC structure has been demonstrated with the energy density of 49.43 Wh·kg-1 and power density of 2700 W·kg-1, thus enabling lightening a red light-emitting diode. The current strategy might pave the way for CaMoO4 for practical applications for high-power supercapacitors.

Point-of-care breath sample analysis by semiconductor-based E-Nose technology discriminates non-infected subjects from SARS-CoV-2 pneumonia patients: a multi-analyst experiment.

Metal oxide sensor-based electronic nose (E-Nose) technology provides an easy to use method for breath analysis by detection of volatile organic compound (VOC)-induced changes of electrical conductivity. Resulting signal patterns are then analyzed by machine learning (ML) algorithms. This study aimed to establish breath analysis by E-Nose technology as a diagnostic tool for severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pneumonia within a multi-analyst experiment. Breath samples of 126 subjects with (n=63) or withoutSARS-CoV-2 pneumonia (n=63) were collected using the ReCIVA® Breath Sampler, enriched and stored on Tenax sorption tubes, and analyzed using an E-Nose unit with 10 sensors. ML approaches were applied by three independent data analyst teams and included a wide range of classifiers, hyperparameters, training modes, and subsets of training data. Within the multi-analyst experiment, all teams successfully classified individuals as infected or uninfected with an averaged area under the curve (AUC) larger than 90% and misclassification error lower than 19%, and identified the same sensor as most relevant to classification success. This new method using VOC enrichment and E-Nose analysis combined with ML can yield results similar to polymerase chain reaction (PCR) detection and superior to point-of-care (POC) antigen testing. Reducing the sensor set to the most relevant sensor may prove interesting for developing targeted POC testing.

Influence of soil microplastic contamination on maize (Zea mays) development and microbial dynamics

BackgroundMicroplastics are contaminants in soil ecosystems that alter biophysical processes, affect plant growth, ecosystems and humans in the long run. This study was conducted to investigate the influence of soil microplastic contamination on the growth, development, and microbial dynamics of maize (Zea mays).Composite soil samples were collected from the farm from 0 to 10 cm depth. Physicochemical properties were assessed before maize seed sowing. Three soil weight categories were treated with 30 g, 20 g and 10 g microplastics. Soil physicochemical properties and heavy metal content in maize plants were analyzed. Morphological parameters, microbial counts, and microorganism identification were conducted. FTIR analysis was carried out in selected plant parts.ResultsThe study revealed a pH range of 5.00–6.70, electrical conductivity of 70–158 µS/cm, organic carbon and organic matter, total nitrogen, average phosphorus content, clay and silt content. The concentrations of heavy metals in plant parts were within WHO standard limits of 425.5 and 500 mg/kg for iron and manganese, but above the limits of 40, 60, and 350 mg/kg for copper, zinc and magnesium. The plant had various leaf sizes and heights, with chlorosis and necrotic activity ranging from 0.33 to 2.67, and a range of 1.33 to 6.33, respectively. Soil samples showed a total bacterial count (TBC) of 2.00 × 103 cfu/g to 7.60 × 104 cfu/g and a total fungal count (TFC) of 4.00 × 103 cfu/g to 2.20 × 104 cfu/g. Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, Staphylococcus epidermidis, Proteus mirabilis and Bacillus cereus had percentage occurrences of 44.31, 21.17, 9.12, and 3.26%, respectively. Penicillium notatum was the most prevalent, while Fusarium spp. was the least prevalent. The FTIR analysis of maize seeds from soil samples A, B, and C revealed various organic compounds, with opium powder and streptomycin sulphate being the most abundant. The study revealed that pot B had the highest microplastic concentration at 1 WAS, while pot C had the lowest at 0.10 mg/kg, indicating a differential soil microplastic accumulation.ConclusionMicroplastics impact soil health, plant growth, and nutrient cycling, necessitating sustainable agriculture. Long-term research is needed to understand ecological and physiological impacts and explore remediation techniques.

A Metalgel with Liquid Metal Continuum Immobilized in Polymer Network.

Gels are formed by fluids that expand throughout the whole volume of 3D polymer networks. To unlock unprecedented properties, exploring new fluids immobilized in polymer networks is crucial. Here, a new liquid metal-polymer gel material termed "metalgel" is introduced via fluid replacement strategy, featuring 92.40%vol liquid metal fluid as a continuum immobilized by interconnected nanoscale polymer network. The unique structure endows metalgel with high electrical conductivity (up to 3.18×106 S·m‒1), tissue-like softness (Young's modulus as low as 70kPa), and low gas permeability (4.50×10‒22m2·s‒1·Pa‒1). Besides, metalgel demonstrates electrical stability under extreme deformations, such as being run over by a 4.5-metric-tonne truck, and maintains its integrity in various environments for up to 180 days. The immobilization of high-volume-fraction liquid metal fluid is realized by electrostatic interactions is further revealed. Potential applications for metalgel are diverse and include soft electromagnetic shielding, hermetic sealing, and stimulating/sensing electrodes in implantable bioelectronics, underscoring its broad applicability.

Enhancing thermal stability and electrical conductivity performance of silica aerogel via graphene oxide integration

Enhancing thermal stability and electrical conductivity performance of silica aerogel via graphene oxide integration

A reduced graphene oxide-coated conductive surgical silk suture targeting microresistance sensing changes for wound healing

AbstractConventional sutures used in surgical procedures often lack the capability to effectively monitor physical and chemical activities or the microbial environment of surgical wounds due to their inadequate mechanical properties, insufficient electrical accuracy and unstability. Here, we present a straightforward layer-by-layer coating technique that utilizes 3-glycidoxypropyltrimethoxysilane (CA), graphene oxide (GO), and ascorbic acid (AA) to develop conductive silk-based surgical sutures (CA-rGSFS). The CA-rGSFS feature a continuous reduced graphene oxide (rGO) film on their surface, forming robust hydrogen bonds with silk fibroin. The reduction process of rGO is confirmed through Raman analysis, demonstrating an enhanced D peak to G peak ratio. Notably, the CA-rGSFS exhibit exceptional mechanical properties and efficient electron transmission, with a knot-pull tensile strength of 2089.72 ± 1.20 cN and an electrical conductivity of 130.30 ± 11.34 S/m, respectively, meeting the requirements specified by the United States Pharmacopeia (USP) for 2-0 sutures. These novel CA-rGSFS demonstrate the ability to accurately track resistance changes in various fluid environments with rapid response, including saline, intestinal, and gastric fluids. The suture also retains remarkable stretchablility and stability even after enduring 3000 tensile cycles, highlighting their potential for precise surgical site monitoring during the wound healing process.

Exploring the Crystal Structure and Electronic Properties of γ-Al2O3: Machine Learning Drives Future Material Innovations.

For decades, researchers have struggled to determine the precise crystal structure of γ-Al2O3 due to its atomic-level disorder and the challenges associated with obtaining high-purity, high-crystallinity γ-Al2O3 in laboratory settings. This study investigates the crystal structure and electronic properties of γ-Al2O3 coatings under the influence of an external electric field, integrating machine learning with density functional theory (DFT). A potential 160-atom supercell structure was identified from over 600,000 γ-Al2O3 configurations and confirmed through high-resolution transmission electron microscopy and selected area electron diffraction. The findings indicate that γ-Al2O3 deviates from the conventional spinel structure, suggesting that octahedral vacancies can reduce the system's energy. Under an external electric field, the material's band structure and density of states (DOS) undergo significant changes: the bandgap narrows from 3.996 to 0 eV, resulting in metallic behavior, while the projected density of states (PDOS) exhibits peak broadening and splitting of oxygen atom PDOS below the Fermi level. These alterations elucidate the variations in the electrical conductivity of alumina coatings under an electric field. These findings clarify the mechanisms of γ-Al2O3's electronic property modulation and offer insights into its covalent and ionic mixed bonding as a wide-bandgap semiconductor. This discovery is essential for understanding dielectric breakdown in insulating materials.

Electrostatically-enhanced two-stage low-temperature tempering: Effects on the quality of frozen tan mutton

The two-stage low-temperature tempering (TLT) and TLT assisted by electrostatic fields (TLT-1500/2000/2500/3000) were developed to investigate their effects on the quality of frozen Tan mutton. The results demonstrated that both TLT and TLT-1500/2000/2500/3000 significantly (P < 0.05) enhanced the tempering rate compared to refrigerator tempering (4 °C, RT). The analysis of tempering, cooking, and centrifugal losses, along with the evaluation of electrical conductivity, pH, and TVB-N, showed that the water retention capacity and freshness of Tan mutton treated with TLT-2500 were closest to those of fresh Tan mutton. Scanning electron microscopy analysis demonstrated that TLT-2500 best maintained the tissue integrity of Tan mutton, while low-field nuclear magnetic resonance analysis revealed it contained the highest immobile water and least free water. Furthermore, Tan mutton treated with TLT-2000 and TLT-2500 exhibited minimal lipid oxidation and color change. In contrast, the most significant changes in all indicators were observed after RT.