Changes In Conductivity Research Articles

Effects of Long-Term Reed Plantation on Saline Habitat

In recent years, the improvement and utilization of saline-alkaline soil has gradually shifted from engineering measures to biological measures. As a salt-tolerant plant, the reed has been preliminarily proven to have a role in improving saline-alkaline land. In order to explore the long-term effect of planting unharvested reeds on the improvement of saline-alkaline land, a pilot plot was set up in Fuping Pilot Test Base (34° 42'180"E; 109°11'49" N) near Lubo Beach, Fuping, Shaanxi, in 2012 to ascertain the improvement effect of long-term reed cultivation on saline–alkaline land. The objective was to study the long-term changes in soil pH, electrical conductivity, Ca2+, Mg2+, Cl-, SO42-, HCO3-, and CO32- contents, soil particle size and soil fertility. Results showed that (i) reed cultivation could effectively reduce soil salinization in the long term. From 2012 to 2022, the average pH of saline soil decreased from 9.42 to 8.86, and the electrical conductivity decreased from 1.20 μS/cm to 0.70 μS/cm. (ii) Reed cultivation considerably reduced the contents of Ca2+, Mg2+, Cl-, SO42-, HCO3-, and CO32- in the soil in the long term, and the reduction in each index was 5.9, 41.7, 63.5, 90.6, 81.7, 90.6, 77.9and 90.3%, respectively. (iii) Reed cultivation changed the soil structure. The soil texture of the 0–60 cm soil layer changed from silty sandy loam to silty loam from 2018 to 2022. (iv) Long-term reed planting without harvesting effectively improved soil fertility. In 2012, the content of soil organic matter was only 2.74 g/kg, but in 2022, the value reached 12.8 g/kg. Reed planting improved the physical and chemical properties of saline soil. Therefore, biological restoration of reed can be considered in low-lying saline–alkaline areas with high water volumes. Bangladesh J. Bot. 53(3): 665-672, 2024 (September) Special

Numerical assessments of geometry, proximity and multi-electrode effects on electroporation in mitochondria and the endoplasmic reticulum to nanosecond electric pulses

Most simulations of electric field driven bioeffects have considered spherical cellular geometries or probed symmetrical structures for simplicity. This work assesses cellular transmembrane potential build-up and electroporation in a Jurkat cell that includes the endoplasmic reticulum (ER) and mitochondria, both of which have complex shapes, in response to external nanosecond electric pulses. The simulations are based on a time-domain nodal analysis that incorporates membrane poration utilizing the Smoluchowski model with angular-dependent changes in membrane conductivity. Consistent with prior experimental reports, the simulations show that the ER requires the largest electric field for electroporation, while the inner mitochondrial membrane (IMM) is the easiest membrane to porate. Our results suggest that the experimentally observed increase in intracellular calcium could be due to a calcium induced calcium release (CICR) process that is initiated by outer cell membrane breakdown. Repeated pulsing and/or using multiple electrodes are shown to create a stronger poration. The role of mutual coupling, screening, and proximity effects in bringing about electric field modifications is also probed. Finally, while including greater geometric details might refine predictions, the qualitative trends are expected to remain.

Embolism propagation does not rely on pressure only: time-based shifts in xylem vulnerability curves of angiosperms determine the accuracy of the flow-centrifuge method.

Centrifuges provide a fast approach to quantify embolism resistance of xylem in vulnerability curves (VCs). Since embolism formation is assumingly driven by pressure only, spin time is not standardised for flow centrifuge experiments. Here, we explore to what extent embolism resistance could be spin-time dependent, and hypothesise that changes in hydraulic conductivity (Kh) would shift VCs towards higher water potential (Ψ) values over time. We quantified time-based shifts in flow-centrifuge VCs and their parameter estimations for six angiosperm species by measuring Kh over 15minutes of spinning at a particular speed, before a higher speed was applied to the same sample. We compared various VCs per sample based on cumulative spin time, and modelled the relationship between Kh, Ψ, and spin-time. Time-based changes of Kh showed considerable increases and decreases at low and high centrifuge speeds, respectively, which generally shifted VCs towards more positive Ψ values. Values corresponding to 50% loss of hydraulic conductivity (P50) became less negative by up to 0.72MPa in Acer pseudoplatanus, and on average by 8.5% for all six species compared to VCs that did not consider spin-time. By employing an asymptotic exponential model, we estimated time-stable Kh, which improved the statistical significance of VCs in 5 of the 6 species studied. This model also revealed the instability of VCs at short spin times with embolism formation in flow-centrifuges following a saturating exponential growth curve. Although pressure remains the major determinant of embolism formation, spin-time should be considered in flow-centrifuge VCs because not considering the time-dependent stability of Kh overestimates embolism resistance. This spin-time artefact is species-specific, and likely based on relatively slow gas diffusion that is associated with embolism propagation. The accuracy of VCs is improved by determining time-stable Kh values for each centrifuge speed, without considerably extending the experimental time to construct VCs.

Design of non-heat-treatable Al-Fe-Ni alloys with high electrical conductivity and high strength via CALPHAD approach

Electrical conductivity and strength are two critical properties concerned for rotors materials in electric vehicles. However, the two properties are often mutually exclusive in cast Al alloys. The present work proposes a novel non-heat-treatable Al-Fe-Ni alloy by considering the intermetallic compound’s content and morphology. With the modification of Ni and Fe content, the solidification path of designed alloy were calculated to predict the phase composition, which would greatly impact their performance. The as-cast Al-2Fe-1Ni (wt%) alloy exhibits comprehensive properties with an ultimate tensile strength of 131.2±2.5 MPa, an elongation of 20.2±3.6 % and an electrical conductivity up to 52.0±0.1 %IACS. The eutectic microstructure of Al13(Fe,Ni)4+α-Al in Al-2Fe-1Ni alloy accounts for over 90 %, much larger than the eutectic content in Al-0.4Fe-3.4Ni and Al-1Fe-1Ni alloys. The fine eutectics in Al-2Fe-1Ni alloy improve the second-phase strengthening effects and plastic deformation capability. In addition, the fibrous rod-like intermetallic reduces the electron scattering during the propagation process and leaves more space for free electron movement. The dominant second phase transforms from Al3Ni phase to Al9FeNi phase, further enhancing the thermal stability of the alloy. After aging treatment at 180 °C for 100 h, it shows no noticeable change in electrical conductivity and mechanical properties. It is hoped that this work can provide a new design approach for high-strength and high-conductivity Al alloys.

Highly thermally conductive and shape-stabilized phase change materials with desirable solar/electric-to-thermal conversion performance based on high-modulus graphite/PVA foam

The widespread utilization of phase change materials (PCMs) has been impeded by challenges such as leakage, low thermal/electrical conductivity, and inadequate light absorption. Although constructing interconnected three-dimensional (3D) carbon networks within PCMs can mitigate these issues, their complex and energy-intensive fabrication processes, coupled with insufficient mechanical strength causing significant leakage and collapse of liquefied PCMs under external loads or impacts, hinder their practical application. Herein, we present a novel approach for the preparation of 3D graphite/polyvinyl alcohol foam (GPF) through a simple vacuum foaming combined with air-drying method. The obtained GPF-5 exhibits impressive compression strength (4.46 MPa) and compression modulus (93.1 MPa) at low density of 0.30 g/cm3. Upon impregnation with polyethylene glycol (PEG), GPF-5/PEG exhibits notable mechanical strength (7.62 MPa), contributing to its thermal shape stability and resistance to leakage. Even when subjected to temperatures above the melting point of PEG under external loads, GPF-5/PEG maintains its original shape without any liquid leakage. Due to the efficient construction of 3D thermal conductivity pathways within GPF, GPF-5/PEG demonstrates a high thermal conductivity of up to 3.48 W/m K−1 with graphite contents of 21.1 wt%, representing an increase of 136 % and 1640 % compared to graphite/PEG (with equivalent graphite content) and pure PEG, respectively. Additionally, GPF-5/PEG displays high latent heat of melting (136.8 J/g) and superior thermal cycling stability. Moreover, GPF-5/PEG demonstrates high solar-to-thermal and electric-to-thermal energy conversion capabilities, highlighting their potential for diverse applications. The work offers a rational strategy for fabricating high-modulus carbon foam, which can be used for PCMs-based multi energy conversion and storage systems with high thermo-mechanical properties.

Modelling of oxide fuel restructuring during first hours after a reactor reaches its power

There is a substantial amount of experimental data that confirm the peculiarity of the oxide fuel behavior during the first hours after a reactor reaches its power. With an increase in temperature during the said period, oxide fuel pellets crack because of a significant temperature gradient. Further developments occur due to the accumulation and redistribution of fission products, and manifest themselves as changes in the fuel matrix porosity and the formation (or diameter increase) of a central hole. The zones that differ in their microstructure, density and thermal conductivity are formed along the fuel pellet radius. As the oxide fuel composition and restructuring result in its thermal conductivity change, it is important to pay attention to the formulas used in the stress-strain state calculations of a fuel element. The methodology for calculating changes in the oxide fuel porosity and the pellet’s internal diameter is proposed and based on the published research papers dedicated to the study of oxide fuel properties and behavior during the first hours after a reactor reaches its power. Тhe methodology was tested using real experimental data on the porosity redistribution along the fuel pellet radius. The presence and the size of the pellet’s inner hole, as well as changes in the fuel matrix porosity, have a noticeable effect on the maximum temperature value. Taking into account the pellet structure evolution while performing computational simulation of the fuel rod operation under irradiation allows assessing the fuel element’s operability more accurately. The proposed methodology can be used in computer codes designed to calculate the stress-strain state of cylindrical fuel elements of fast reactors.

Relationship between regional sympathetic vascular transduction and sympathetic transduction of blood pressure in young adults at rest.

A burst of muscle sympathetic nerve activity (MSNA) induces vasoconstriction that transiently reduces regional vascular conductance and increases systemic blood pressure (BP) over the subsequent 4-8 cardiac cycles. These responses are termed sympathetic neurovascular transduction and sympathetic transduction of BP, respectively. Sympathetic transduction of BP is commonly calculated and interpreted as a proxy measure for regional sympathetic neurovascular transduction, despite the systemic nature of BP regulation. The present analysis tested whether the peak change in signal-averaged sympathetic transduction of BP was correlated to the change in regional sympathetic vascular transduction at rest. Fourteen adults (5 females, 23±3 years) arrived at the laboratory, ate a standardized meal, and rested for 90-120 minutes. MSNA (fibular nerve microneurography), heart rate (electrocardiography), beat-to-beat BP (finger photoplethysmography), and superficial femoral artery blood flow (Doppler ultrasound) were obtained continuously for 10 minutes in the supine position. Femoral vascular conductance was calculated as blood flow divided by mean arterial BP. The peak change in diastolic BP following a burst of MSNA was correlated to the corresponding nadir change in femoral vascular conductance (r=-0.58 [-0.07 to -0.85], P=0.03) and superficial femoral artery blood flow (r=-0.54 [-0.17 to -0.83], P=0.04). The nadir change in diastolic BP in cardiac cycles not following a MSNA burst was correlated to the peak change in femoral vascular conductance (r=-0.42 [-0.83 to 0.00], p=0.05) but not superficial femoral artery blood flow (r=0.41 [-0.77 to 0.15], p=0.14). In conclusion, more commonly assessed sympathetic transduction of BP provides moderate insight into regional sympathetic neurovascular transduction.

Effects of lattice instability on the thermoelectric behavior of kagome metal ScV6Sn6

Kagome metal ScV6Sn6 has been a subject of interest due to the emergence of a first-order structural phase transition with intriguing charge density wave behavior below the transition temperature Tc ∼ 92 K. To explore the thermoelectric properties and provide experimental insights into the nature of the phase transition, we have carried out a combined study by means of the electrical resistivity, Seebeck coefficient, and thermal conductivity measurements on single crystalline ScV6Sn6. Pronounced features near Tc have been characterized by all measured physical quantities. In particular, the Seebeck coefficient exhibits a marked reduction as lowering temperature across Tc, attributed to an imbalance of the contribution from different type of carriers induced by the structural phase transition. From the examination of the electronic and lattice thermal conductivities, we obtained a confirmation that the observed enhancement at Tc is essentially caused by the change of the lattice thermal conductivity, demonstrating the primary importance of lattice distortions for the heat transport of ScV6Sn6. In addition, the lattice thermal conductivity above Tc was found to increase monotonically with temperature. We associated the peculiar phenomenon with lattice fluctuations, highlighting the essence of structural instability in the kagome lattice ScV6Sn6. These results add to the knowledge about the thermal transport properties in kagome materials with a hexagonal HfFe6Ge6-type structure.

Changes in Microstructure, Mechanical Properties, and Electrical Conductivity of Severely Drawn AA1070 Wire with Annealing

The drawing process severely deforms commercial AA1070 alloy for electrical wire, reducing a rod from a diameter of 2.0 mm to 0.4 mm, followed by annealing. The annealing process was conducted at various temperatures ranging from 200℃ to 450℃, with each temperature maintained for 1hour. The effects of increasing annealing temperature on the microstructure, mechanical properties, and electrical properties of the Al wire were investigated in detail. The drawn Al wire showed a severely deformed microstructure and fiber texture that {110}<111> and {112}<111> components strongly developed. As the annealing temperature increased, the deformation structure changed into recrystallization structure over all regions. However, the fiber texture still strongly remained even in the specimens annealed at higher temperatures. The hardness decreased with increasing annealing temperature due to the occurrence of recovery and/or recrystallization. The strength also continued to decrease as the annealing temperature increased. However, elongation gradually increased with increase of annealing temperature to 250℃; above 275℃, it increased particularly sharply. The electric conductivity tended to increase slightly with increasing annealing temperature, reaching a maximum value of 62.2%IACS at 300℃. Changes in microstructure, mechanical properties and electrical conductivity with annealing of commercially drawn AA1070 were compared with those of the previous study.

Acoustoelectric Effect due to an In-Depth Inhomogeneous Conductivity Change in ZnO/Fused Silica Substrates

The acoustoelectric (AE) effect induced by the absorption of ultraviolet (UV) light at 365 nm in piezoelectric ZnO films was theoretically and experimentally studied. c-ZnO films 4.0 µm thick were grown by the RF reactive magnetron sputtering technique onto fused silica substrates at 200 °C. A surface acoustic wave (SAW) delay line was fabricated with two split-finger Al interdigital transducers (IDTs) photolithographically implemented onto the ZnO-free surface to excite and reveal the propagation of the fundamental Rayleigh wave and its third harmonic at about 39 and 104 MHz. A small area of a few square millimeters on the surface of the ZnO layer, in between the two IDTs, was illuminated by UV light at different light power values (from about 10 mW up to 1.2 W) through the back surface of the SiO2 substrate, which is optically transparent. The UV absorption caused a change of the ZnO electrical conductivity, which in turn affected the velocity and insertion loss (IL) of the two waves. It was experimentally observed that the phase velocity of the fundamental and third harmonic waves decreased with an increase in the UV power, while the IL vs. UV power behavior differed at large UV power values: the Rayleigh wave underwent a single peak in attenuation, while its third harmonic underwent a further peak. A two-dimensional finite element study was performed to simulate the waves IL and phase velocity vs. the ZnO electrical conductivity, under the assumption that the ZnO layer conductivity undergoes an in-depth inhomogeneous change according to an exponential decay law, with a penetration depth of 325 nm. The theoretical results predicted single- and double-peak IL behavior for the fundamental and harmonic wave due to volume conductivity changes, as opposed to the AE effect induced by surface conductivity changes for which a single-peak IL behavior is expected. The phenomena predicted by the theoretical models were confirmed by the experimental results.

A-257 Revolutionizing Fungal Infection Diagnosis: A Sensitive, Cost-Effective, and Time-Efficient Solution

Abstract Background Fungal infection detection is essential for optimizing therapeutic strategies, preventing complications, enhancing overall health, and alleviating the financial burden, and preventing transmission. According to the CDC, fungal illness resulted in 75,000 hospital admissions and 9 million outpatient visits annually, with 7,199 deaths predicted in the United States in 2021. The rising prevalence of fungal infections, influenced by factors such as population expansion and evolving treatment strategies poses a growing challenge to achieving an early and accurate diagnosis. There is the crucial need for improved detection methods to promptly identify various fungal infections, including Candida species, spanning from skin issues to potentially fatal systemic diseases, ultimately reducing associated morbidity and mortality. Severe and profound infections with life-threatening potential are common in individuals with compromised immune systems and those who are hospitalized. This risk is notably elevated among patients with organ transplants, immunosuppressive treatments, diabetes, recent broad-spectrum antibiotic usage, catheter utilization, and extended hospitalization periods. Our advancement seeks to introduce innovative methods leveraging carbon-based nanomaterials for the detection of fungal infections, offering distinct advantages including cost-effectiveness, ease of operation, and time efficiency compared to conventional techniques. Methods Our technology utilizes carbon-based nano materials, a promising advancement in nanotechnology to detect fungal infections, especially Candida manifestations. The samples are brought into contact with pre-probed carbon-based nano materials sensors maintained at a specific annealing temperature, facilitating nucleic acid hybridization. Subsequently, alterations in the carbon nanotube's electrical signal are observed, indicating a change in conductivity. This change can allow for the measurement of a voltage difference across a continuous flow of electricity, correlating with the concentration of targets present in the sample, thereby enabling the detection of specific microorganisms. No change was noticed in electrical properties of carbon-based nano material when negative experiments were conducted. Results The initial findings showed the presence of specific microorganisms within the sample in less than 15 minutes with carbon-based nano materials sensors. Comparative analysis of the electrical signal magnitude values obtained from carbon nanotube measurements against the corresponding CT values from quantitative PCR (qPCR) provides insights into the correlation between the electrical readouts and molecular quantification, offering a comprehensive evaluation of the nanotube-based detection system's performance in diagnostics procedure. Conclusions Unlike conventional blood culture and qPCR, our technology, delivers outcomes with heightened sensitivity, cost-effectiveness, and time efficiency. Our team's uncomplicated sample collection method notably reduces the intricacies of sample preparation, enabling the proper disposal of both the sample container and sensor part without requiring disassembly. Enhanced sensitivity, coupled with the economical and rapid detection capabilities of advanced technologies like carbon-based nano materials, is a promising alternative for the accurate and efficient diagnosis of fungal infections. Consequently, the implementation of such technology not only enhances diagnostic efficiency but also contributes to better patient outcomes through prompt and targeted therapeutic interventions.

In-plane electrical conductivity of PEDOT:PSS/Halloysite composite thin films

PEDOT:PSS has found numerous applications in the field of advanced materials, especially in the development of organic electronics. Embedding nanoparticles into the polymer matrix has emerged as an effective strategy to modify the properties of PEDOT:PSS and develop advanced functional composites. Over the past decade, Halloysite nanotubes (HNT) have garnered significant interest and utility as nanofillers and/or templates due to their unique physical-chemical properties, small size, relatively low cost, and large availability. Interestingly, pairing PEDOT:PSS with non-conductive HNT has been demonstrated to enhance the charge transport properties of the composite film. Our discoveries show how the HNT can act as scaffolding for PEDOT:PSS by improving the local ordering of PEDOT chains and enabling the formation of conductive pathways. Consequently, the mechanism responsible for the observed changes in conductivity and the correlation between PEDOT:PSS and insulating nanofillers (HNT) could be different to that previously proposed. Hence, in this work it was observed that PEDOT:PSS/HNT composite films exhibited a non-linear conductivity dependence as a function of the HNT loading. From thermogravimetric analysis, infrared and UV-Vis-NIR spectroscopies, as well as impedance spectroscopy, a more complex interaction between the polymer chains and the nanotubes is revealed. Our study includes the modification of the interaction between the PEDOT chains and the nanofillers by using the secondary doping effect and functionalization of the nanotubes, which confirms our findings. These results represent a significant progress toward a deeper understanding of the emergence of a conductive polymer network on the nanofiller surface, leading to improvements in the electrical conductivity in the composite material.

Thermoelectric and electrical transport properties of mixed-conducting multicomponent oxides based on Ba(Zr,Ce)O3-δ

In this work, the chosen physicochemical properties of single-phase multicomponent oxides BaTi1/8Fe1/8Co1/8Y1/8Zr1/8Sn1/8Ce1/8Hf1/8O3-δ and BaTi1/9Fe1/9Co1/9Y1/9Zr1/9Sn1/9Ce1/9Hf1/9Bi1/9O3-δ were studied. The microstructure of the compounds strongly depended on the presence of bismuth in the structure. The electrical transport studies showed a level of electrical conductivity of ∼10-3 - 10-2 S/cm in the temperature range 673 – 1073 K. Electrical conductivity was thermally activated and the dominant conduction mechanism was the hopping of small polarons. Moreover, total electrical conductivity changes in the dry and humidified atmosphere at lower temperatures due to the presence of protonic defects in the structure. Thermoelectric measurements showed a relatively high value of the Seebeck coefficient for studied ceramics. Its values ranged between 50 and 250 μV/K depending on the sample and temperature. The Seebeck coefficient sign was positive, meaning that electron holes and/or oxygen vacancies were predominant charge carriers in oxidising atmospheres. Additionally, the Seebeck coefficient was found to be different in the humidified atmosphere which indicates an influence of protonic defects on thermoelectric transport. The obtained power factor Pf turned out to be low and dependent on the presence of protonic defects in the structure. This indicates, that the efficiency of the MOs-based operating thermoelectric generators can be controlled by changing the partial pressure of water vapor.

A Janus WSi2P2As2 monolayer: A promising material for detecting NO2 with excellent sensitivity, selectivity, reversibility, and humidity resistance

Realizing highly sensitive, selective, humidity-resistant, and reversible detection of hazardous gas molecules with low detection limit in the air environment at room temperature is essential. Herein, we predict a novel two-dimensional Janus WSi2P2As2 material and propose a NO2 gas sensor with excellent response, selectivity, humidity resistance, and reversibility based on WSi2P2As2, by employing density functional theory, statistical thermodynamic modeling, and the non-equilibrium Green’s function approach. The Janus WSi2P2As2 monolayer is a stable semiconductor with a direct band gap of 0.85 eV and an intrinsic out-of-plane dipole moment. We study the sensing properties of the Janus WSi2P2As2 monolayer towards several typical toxic gases (NO, NO2, NH3, SO2, and H2S). All the gas molecules are physically adsorbed on the surface. Different adsorption energies and electronic structures are found for the top- and bottom-surface adsorptions due to the intrinsic dipole of the Janus WSi2P2As2. The experimental viability is characterized by the adsorption density and the recovery time. The statistical estimation of the adsorption density shows that the oxide gases can be adsorbed practically even at ultra-low concentration of part per billion (ppb) at room temperature. The rapid natural desorption of these toxic gases at 300 K indicates the recyclability of the WSi2P2As2 material. Furthermore, we evaluate the sensing performance of the WSi2P2As2-based gas sensor by the conductance change. The sensor exhibits ultra-response of 374 % and excellent selectivity towards NO2 molecules. Importantly, the sensor remains operating with high performance in the humid environment and air environment. These results demonstrate that the Janus WSi2P2As2 is a promising gas-sensing material for the NO2 detection.

Examining the Mid to Long‐Term Variability in Saturated Hydraulic Conductivity of Sandy Soils and Its Influencing Factors Under Constant Head Test in the Laboratory

AbstractSaturated hydraulic conductivity (Ks) is a crucial parameter that influences water flow in saturated soils, with applications in various fields such as surface water runoff, soil erosion, drainage, and solute transport. However, accurate determination of Ks is challenging due to temporal and spatial uncertainties. This study addresses the knowledge gap regarding the long‐term behavior of Ks in sandy soils with less than 10% fine particles. The research investigates the changes in Ks over a long period of constant head tests and examines the factors influencing its variation. Two sandy samples were tested using a hydraulic conductivity cell, and the hydraulic head and discharge were recorded for over 50 days. The results show a general decline in Ks throughout the test, except for brief periods of increase. At the end of both tests, there are noticeable reductions in the saturated hydraulic conductivities of the samples, with one sample being 96% and the other sample 91% less than the maximum recorded saturated hydraulic conductivity during the tests. Furthermore, the relationship between flow rate and hydraulic head gradient does not follow the expected linear correlation from Darcy's law, highlighting the complex nature of sandy soil saturated hydraulic conductivity. The investigation of soil properties in three different sections of the samples before and after the tests revealed a decrease in the percentage of fine particles and a shift in specific gravity from the bottom to the top of the sample, suggesting particle migration along the flow direction. Factors such as clogging by fine particles and pore pressure variation contribute to the changes in Ks. The findings of this research show the importance of considering changes of saturated hydraulic conductivity during constant‐head laboratory tests. Therefore, this study provides evidence for the requirement to further assess the laboratory methods for measurement of the saturated hydraulic conductivity in sandy soil mixtures.

Plasma coupled with ultrasonic for degradation of organic pollutants in water: Revealing the generation of free radicals and the dominant degradation pathways

This study explores the synergistic effects of dielectric barrier discharge (DBD) plasma coupled with ultrasound (US) in the degradation of organic pollutants in water. The optimal degradation conditions were determined to be 100W ultrasonic power, 190V DBD plasma voltage, and neutral pH. The combination of DBD plasma and US significantly enhances the generation of reactive species (·OH, ·O2-, and 1O2), leading to a 97.3% degradation efficiency of methyl orange (MO), which is 17.3% higher than DBD plasma alone. Electron spin resonance (ESR) identified ·OH, ·O2-, and 1O2 in DBD/US system, and radical scavengers were employed to elucidate their roles. The degradation process was assessed through changes in pH, conductivity, TOC and COD, with characterization and analysis via UV-Vis and LC-MS. By combining LC-MS with density functional theory (DFT) calculations, nine intermediates were identified and three degradation pathways dominated by free radicals were established. Additionally, the DBD/US system treated wastewater containing sulfamethoxazole (SMX), sulfadiazine (SDZ), tetracycline (TC), and ciprofloxacin (CIP), achieving degradation rates exceeding 80%. These findings suggest that the DBD/US coupled system holds promising potential for treating organic pollutant wastewater.

Sex-Dependent Changes in Gonadotropin-Releasing Hormone Neuron Voltage-Gated Potassium Currents in a Mouse Model of Temporal Lobe Epilepsy.

Temporal lobe epilepsy (TLE) is the most common focal epilepsy in adults, and people with TLE exhibit higher rates of reproductive endocrine dysfunction. Hypothalamic gonadotropin-releasing hormone (GnRH) neurons regulate reproductive function in mammals by regulating gonadotropin secretion from the anterior pituitary. Previous research demonstrated GnRH neuron hyperexcitability in both sexes in the intrahippocampal kainic acid (IHKA) mouse model of TLE. Fast-inactivating A-type (I A) and delayed rectifier K-type (I K) K+ currents play critical roles in modulating neuronal excitability, including in GnRH neurons. Here, we tested the hypothesis that GnRH neuron hyperexcitability is associated with reduced I A and I K conductances. At 2 months after IHKA or control saline injection, when IHKA mice exhibit chronic epilepsy, we recorded GnRH neuron excitability, I A, and I K using whole-cell patch-clamp electrophysiology. GnRH neurons from both IHKA male and diestrus female GnRH-GFP mice exhibited hyperexcitability compared with controls. In IHKA males, although maximum I A current density was increased, I K recovery from inactivation was significantly slower, consistent with a hyperexcitability phenotype. In IHKA females, however, both I A and I K were unchanged. Sex differences were not observed in I A or I K properties in controls, but IHKA mice exhibited sex effects in I A properties. These results indicate that although the emergent phenotype of increased GnRH neuron excitability is similar in IHKA males and diestrus females, the underlying mechanisms are distinct. This study thus highlights sex-specific changes in voltage-gated K+ currents in GnRH neurons in a mouse model of TLE and suggesting potential sex differences in GnRH neuron ion channel properties.

Both edge substitution effects on thermal conductivity of armchair graphene nanoribbons under tensile strain: From equilibrium molecular dynamics simulations

Thermal conductivity and phonon spectra change of graphene nanoribbon as function of both side edges substitution and strain is investigated using equilibrium molecular dynamics. Under small strain, the edge’s partial substitution by graphane plays effect role to change the phonon mode of GNR. Under large tensile strain, reduction ratio of thermal conductivity is the largest in case of fluorographane hybrid and the smallest in case of graphane hybrid. Especially, under 16 % strain, the thermal conductivity of GNR is reduced until 13 % by edges substitution of graphane. The phonon spectra shift peaks towards low frequency at high frequency range (>50 THz).

Sensitive detection of Hg(II) on MoS2/NiS2 based on interfacial engineering to accelerate the Ni2+/Ni3+ cycle: Identification the role of atomic-level heterojunction-induced electron transfer in electroanalysis

The valence change of transition metal ions in nanomaterials can highly enhance the electrochemical detection performance toward heavy metal ions (HMIs), and how to further promote the valence change calls enormous concerns in electroanalysis. In this work, an interfacial engineering that combing the MoS2 and NiS2 together to form the MoS2/NiS2 complex is proposed. The density functional theory (DFT) results reveals that the novel atomic-level heterojunction between MoS2 and NiS2 will build an internal electric field (IEF), which leads to an enhanced conductivity and valence change behavior of Ni atoms in MoS2/NiS2 complex, resulting in a superior detection performance. In detail, the formation of atomic-level heterojunctions in the MoS2/NiS2 complex accelerates electron transfer due to the valence changes associated with Ni2+/Ni3+ cycling. The active Mo4+ species on MoS2 act as electron donors, facilitating the reduction of Ni3+ to Ni2+ on NiS2, thereby promoting Ni2+/Ni3+ cycling. As anticipated, the MoS2/NiS2 complex exhibits exceptional detection performance for Hg(II), with a sensitivity of 459.13 μA μM−1 cm−2, surpassing even that of other composite materials. In general, these findings are expected to significantly advance the application of electron transfer acceleration in electroanalysis based on the construction of heterojunction.

Effects of Varying Nano-Montmorillonoid Content on the Epoxy Dielectric Conductivity

This study investigates the correlation between the interface structure and macroscopic dielectric properties of polymer-based nanocomposite materials. Utilizing bisphenol-A (BPA) epoxy resin (EP) as the polymer matrix and the commonly employed layered phyllosilicate montmorillonoid (MMT) as the nanometer-scale dispersive phase, nano-MMT/EP composites were synthesized using composite technology. The microstructure of the composite samples was characterized through XRD, FTIR, SEM, and TEM. Changes in the morphology of the nanocomposite interface were observed with varying MMT content, subsequently impacting dielectric polarization and loss. Experimental measurements of the dielectric spectrum of the nano-MMT/EP were conducted, and the influence of the material interface, at different nano-MMT contents, on the dielectric relaxation was analyzed. The study delves into the effect of the nanocomposite interface structure on ion dissociation and migration barriers, exploring the ionic conductivity of nano-MMT/EP. Lastly, an analysis of the impact of different nano-MMT contents on the dielectric conductivity is presented. From the experimental results, the arranging regularity of polymer molecules in the interface area raises. In the matrix, the ion migration barriers decrease significantly. The higher the MMT content in the interface, the lower the migration barrier is. Until the MMT content exceeds the threshold, the agglomerated micro-particles form, which decreases the polymers’ space distribution regularity, and the ions migration barrier raises. According to the changes in the rule of the ions migration barrier with the composite interface structure content, the reason for dielectric conductivity changes can be judged.