Resistivity Research Articles

Spectral bounds on the entropy flow rate and Lyapunov exponents in differentiable dynamical systems

Abstract Some microscopic dynamics are also macroscopically irreversible, dissipating energy and producing entropy. For many-particle systems interacting with deterministic thermostats, the rate of thermodynamic entropy dissipated to the environment is the average rate at which phase space contracts. Here, we use this identity and the properties of a classical density matrix to derive upper and lower bounds on the entropy flow rate with the spectral properties of the local stability matrix. These bounds are an extension of more fundamental bounds on the Lyapunov exponents and phase space contraction rate of continuous-time dynamical systems. They are maximal and minimal rates of entropy production, heat transfer, and transport coefficients set by the underlying dynamics of the system and deterministic thermostat. Because these limits on the macroscopic dissipation derive from the density matrix and the local stability matrix, they are numerically computable from the molecular dynamics. As an illustration, we show that these bounds are on the electrical conductivity for a system of charged particles subject to an electric field.

A Facile Microwave-Promoted Formation of Highly Photoresponsive Au-Decorated TiO2 Nanorods for the Enhanced Photo-Degradation of Methylene Blue

The integration of noble metal nanoparticles (NPs) effectively modifies the electronic properties of semiconductor photocatalysts, leading to improved charge separation and enhanced photocatalytic performance. TiO2 nanorods decorated with Au NPs were successfully synthesized using a cost-effective, rapid microwave-assisted method in H2O2 and HF media for methylene blue (MB) degradation under visible light illumination. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 physisorption, and UV–vis spectroscopy were employed to characterize the structures, morphologies, compositions, and photoelectronic properties of the as-synthesized materials. The fusing of Au NPs effectively alters the electronic structure of TiO2, enhancing the charge separation efficiency and improved electrical conductivity. The HF treatment promotes the exposure of the highly reactive (001) and (101) crystalline facets. The improved photocatalytic activity of Au/TiO2, achieving 97% efficiency, is attributed to the surface plasmon resonance (SPR) effect of the Au NPs and the presence of oxygen vacancies. The photodegradation of MB using the TiO2/Au photocatalysts follows pseudo-first-order kinetics, highlighting the enhanced catalytic efficiency of the synthesized nanostructures. The exceptional properties of the binary Au/TiO2 photocatalysts, including the SPR effect, exposed crystallographic faces, and efficient charge carrier separation through a decrease in the recombination of electrons and holes, contribute to the photocatalytic degradation of MB.

Integrative multi-omics analysis of chilling stress in pumpkin (Cucurbita moschata).

Pumpkin (Cucurbita moschata) is an important vegetable crop that often suffers from low-temperature stress during growth. However, the molecular mechanism involved in its response to chilling stress remains unknown. In this study, we comprehensively investigated the effect of chilling stress in pumpkin seedlings by conducting physiological, transcriptomic, and metabolomic analyses. Under chilling stress, there was an overall increase in relative electrical conductivity, along with malondialdehyde, soluble sugar, and soluble protein contents, but decreased superoxide dismutase and peroxidase activities and chlorophyll contents in seedling leaves compared with controls. Overall, 5,780 differentially expressed genes (DEGs) and 178 differentially expressed metabolites (DEMs) were identified under chilling stress. Most DEGs were involved in plant hormone signal transduction and the phenylpropanoid biosynthesis pathway, and ERF, bHLH, WRKY, MYB, and HSF transcription factors were induced. Metabolomic analysis revealed that the contents of salicylic acid (SA), phenylalanine, and tyrosine increased in response to chilling stress. The findings indicated that the SA signaling and phenylpropanoid biosynthesis pathways are key to regulating the responses to chilling stress in pumpkins. Overall, our study provides valuable insights into the comprehensive response of C. moschata to chilling stress, enriching the theoretical basis of this mechanism and facilitating the development of molecular breeding strategies for pumpkin tolerance to chilling stress.

Unravelling the Electrical Field Induced Ion Migration in Flexible OLEDs with PEDOT:PSS Electrodes.

The development of flexible organic light-emitting didoes (FOLEDs) has spurred the research on flexible transparent electrodes (FTEs). Poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) is one of the most attractive FTEs due to its adjustable conductivity and compatibility with low-cost and large-scale solution processing techniques. Significantly, highly efficient FOLEDs have been achieved with modified PEDOT:PSS FTEs. However, the intrinsic mechanisms that contribute to device degradation of FOLEDs utilizing PEDOT:PSS FTEs have not yet been fully elucidated. In this work, three ionic liquids (ILs) are used to enhance the electrical conductivity and mechanical flexibility of PEDOT:PSS FTEs. Simultaneously, the influence of the electric field induced ion migration from PEDOT:PSS FTEs on the operational stability of FOLEDs is unraveled. We find that the ILs with larger ionic radii and higher steric hindrance are beneficial to suppressing the electrical field induced ion migration and improving the operational stability of FOLEDs. Finally, large-area and high-performance FOLEDs are achieved based on the IL of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide modified PEDOT:PSS FTEs, which demonstrate a high current efficiency of 98.1 cd/A and a longer lifetime of 66.7 min. This finding may promote the practical application of PEDOT:PSS FTEs in flexible optoelectronics.

Applicability of soil health assessment dominated by biological indicators in facility agriculture

The minimum data set (MDS) is widely used for soil health index (SHI) assessment, with the selection of indicators being crucial. However, biological indicators are less frequently used compared to physical and chemical indicators. This study aimed to establish a biologically-centered MDS for assessing soil health in tomato facility agriculture in Ningbo. Using biochemical, microbiological, and nematode data from 60 continuous cropping soils, we identified key indicators for the MDS. Principal component analysis revealed a strong correlation between the MDS and the total data set (TDS), with the final MDS including available phosphorus, electrical conductivity, β-glucosidase, urease, bacterial Chao1 index, bacterial Shannon index, Ralstonia solanacearum, nematode Shannon index, structure index, and channel index. Random forest modeling showed that the predicted SHI had a high fit with the MDS-SHI, with bacterial and nematode Shannon indices being the most influential predictors, emphasizing the critical role of biological communities in maintaining soil health. Furthermore, the study identified three distinct phases in soil health during long-term continuous cropping: healthy (0–10 years), sub-healthy (11–15 years), and recovery (16–20 years), demonstrating the soil's potential for self-recovery. By incorporating biodiversity as a core component, this biologically-focused MDS provides a more comprehensive and precise method for evaluating soil health in facility agriculture. The findings suggest that this MDS could inform future research and applications in similar agricultural systems. Moreover, the results highlight the vital role of biodiversity in agroecosystem stability, suggesting that future soil health assessments should place greater emphasis on biological indicators to better capture the complexity of soil functions.

Intergrain scattering in polycrystals

Transport through grain boundaries in polycrystals is described from first principles using quantum scattering theory, explicitly including Feshbach resonances to account for intermittently trapped electronic surface states. An effectiveT-matrix is derived then used to calculate the electrical conductivity which exhibits breakdown, a sharp increase at a critical intergrain bias. Under typical conditions where the electron thermal energy,kBT, is much less than the intergrain barrier height,φb, the electrical conductivity has the formσ∼T-1/2e-φb/kBT. Temperature dependence of the conductivity is also considered for thermal energies much larger than the applied bias, as may be realized in tightly-compressed grains.

Integration of Coagulation–flocculation(with Natural Coagulant) to Constructed Wetlands for Color Removal from Tequila Vinasses

The aim of this study was to evaluate a natural coagulant, Moringa oleifera seeds (MOC), to reduce the color concentration in treated tequila vinasses (TVs). TV-A was the effluent of horizontal subsurface flow wetlands (HSSFW); TV-B was the effluent of vertical up-flow wetlands (VUFW); and TV-C was the effluent of vertical down-flow constructed wetlands (VDFW). Raw TVs were also with MOC. Jar tests were performed to find the optimal dose and pH value for apparent color (AC) removal. With the optimal dose and pH for each type of TV, tests were performed in triplicate to evaluate the removal of apparent color (AC), true color (TC), turbidity, total suspended solids (TSS), chemical oxygen demand (COD), and electrical conductivity (EC). For TV-A and TV-B, the optimal values were 1 g/L of MOC and pH 8, and the removals were 52%, 43%, 50% and 72% of AC, turbidity, TC, and TSS, respectively. For TV-C, the optimal values were 2.5 g/L and pH 5, with removals of 66%, 73%, and 98% for AC, TC, and TSS, respectively. For TV-D, the MOC had no coagulant effect in any of the experimental conditions evaluated, probably due to the high concentration of turbidity and TSS in the raw vinasses, which prevented the interaction between MOC and melanoidins. Deeper studies are required to understand and evaluate those factors that influence MOC efficiency so that the coagulation–flocculation process can be optimized.

Evolution laws of charge mobility of transformer oil and pressboard material with temperature and electric field strength

Abstract Charge mobility, a pivotal parameter in the space charge analysis model for oil-pressboard insulation of converter transformer under DC electric fields, predominantly relies on theoretical or empirical data. The prevalent omission of empirical, measurement-based evaluations, combined with the neglect of temperature and electric field intensity effects, introduces uncertainties in the calculation of electric field and charge dynamics. Grounded on the principles of the electroacoustic pulse technique for space charge measurements, our investigation established a temperature-controlled platform to determine the charge-charge mobility in oil and pressboard insulation mediums. Utilizing diverse oil-pressboard insulation systems, this study identified the temporal patterns of both positive and negative charge mobilities and unravelled the mechanisms modulated by temperature and electric field intensity: 1) With increasing temperatures (from 20°C to 80°C) and intensifying electric field strengths (from 5kV/mm to 25kV/mm), the charge mobility within transformer oil and pressboard exhibits a rising trend. Notably, temperature variations exert the most significant influence, yielding amplifications up to 24.8 times. 2) The intrinsic properties of different transformer oils and oil-impregnated pressboards result in pronounced differences in their charge transport behaviours. Specifically, naphthenic-based oil demonstrates enhanced charge mobility relative to its paraffin-based counterpart. In contrast, transformer oils with higher kinematic viscosities exhibit diminished charge mobility compared to those with lower viscosities. 3) A linear relationship is observed between the oil absorption rate and electrical conductivity, aligning closely with the insulating pressboard's charge mobility. The evaluation of electric field and interface charge dynamics in oil-pressboard insulation under both DC and polarity-reversed conditions revealed that the electric field decay in naphthenic-based oil is more rapid than in paraffin-based oils. Moreover, both the magnitude and rate of interface charge accumulation in naphthenic-based oils exceed those in paraffin-based variants, further validating the accuracy of our charge mobility measurements and ensuing analysis.

Alphabet Handwriting Recognition: From Wood-Framed Hydrogel Arrays Design to Machine Learning Decoding.

Handwriting recognition is a highly integrated system, demanding hardware to collect handwriting signals and software to deal with input data. Nonetheless, the design of such a system from scratch with sustainable materials and an easily accessible computing network presents significant challenges. In pursuit of this goal, a flexible, and electrically conductive wood-derived hydrogel array is developed as a handwriting input panel, enabling recognizing alphabet handwriting assisted by machine learning technique. For this, lignin extraction-refill, polypyrrole coating, and polyacrylic acid filling, endowing flexibility, and electrical conduction to wood are sequentially implemented. Subsequently, these woods are manufactured into a 5×5 array, creating a matrix of signals upon handwriting. Efficient handwritten recognition is then achieved through appropriate manual feature extraction and algorithms with low complexity within a computing network, as demonstrated in this work, the strategic choice of expertise-based feature engineering and simplified algorithms effectively boost the overall model performance on handwriting recognition. With potential adaptability, further applications in customized wearable devices and hands-on healthcare appliances are envisioned.

CMC/Gel/GO 3D-printed cardiac patches: GO and CMC improve flexibility and promote H9C2 cell proliferation, while EDC/NHS enhances stability.

In this research, carboxymethyl cellulose (CMC)/gelatin (Gel)/graphene oxide (GO)-based scaffolds were produced by using extrusion-based 3D printing for cardiac tissue regeneration. Rheological studies were conducted to evaluate the printability of CMC/Gel/GO inks, which revealed that CMC increased viscosity and enhanced printability. The 3D-printed cardiac patches were crosslinked with N-(3-dimethylaminopropyl)-n'-ethylcarbodiimide hydrochloride (EDC)/ N-hydroxysuccinimide (NHS) (100:20 mM, 50:10 mM, 25:5 mM) and then characterized by mechanical analysis, electrical conductivity testing, contact angle measurements and degradation studies. Subsequently, cell culture studies were conducted to evaluate the viability of H9C2 cardiomyoblast cells by using the Alamar Blue assay and fluorescence imaging. A high concentration of EDC/NHS (100:20 mM) led to the stability of the patches; however, it drastically reduced the flexibility of the scaffolds. Conversely, a concentration of 25:5 mM resulted in flexible but unstable scaffolds in PBS solution. The suitable EDC/NHS concentration was found to be 50:10 mM, as it produced flexible, stable, and stiff cardiac scaffolds with high ultimate tensile strength (UTS). Mechanical characterization revealed that % the strain at break of C15/G7.5/GO1 exhibited a remarkable increase of 61.03% compared to C15/G7.5 samples. The improvement of flexibility was attributed to the hydrogen bonding between CMC, Gel and GO. The electrical conductivity of 3D printed CMC/Gel/GO cardiac patches was 7.0×10-3 S/cm, demonstrating suitability for mimicking the desired electrical conductivity of human myocardium. The incorporation of 1 wt% of GO and addition of CMC concentration from 7.5 wt % to 15 wt % significantly enhanced relative % cell viability. Overall, although this research is at its infancy, CMC/Gel/GO cardiac patches have potential to improve the physiological function of cardiac tissue.

Two-Dimensional ABS4 (A and B = Zr, Hf, and Ti) as Promising Anode for Li and Na-Ion Batteries

Metal ion intercalation into van der Waals gaps of layered materials is vital for large-scale electrochemical energy storage. Transition-metal sulfides, ABS4 (where A and B represent Zr, Hf, and Ti as monolayers as anodes), are examined as lithium and sodium ion storage. Our study reveals that these monolayers offer exceptional performance for ion storage. The low diffusion barriers enable efficient lithium bonding and rapid separation while all ABS4 phases remain semiconducting before lithiation and transition to metallic states, ensuring excellent electrical conductivity. Notably, the monolayers demonstrate impressive ion capacities: 1639, 1202, and 1119 mAh/g for Li-ions, and 1093, 801, and 671 mAh/g for Na-ions in ZrTiS4, HfTiS4, and HfZrS4, respectively. Average voltages are 1.16 V, 0.9 V, and 0.94 V for Li-ions and 1.17 V, 1.02 V, and 0.94 V for Na-ions across these materials. Additionally, low migration energy barriers of 0.231 eV, 0.233 eV, and 0.238 eV for Li and 0.135 eV, 0.136 eV, and 0.147 eV for Na make ABS4 monolayers highly attractive for battery applications. These findings underscore the potential of monolayer ABS4 as a superior electrode material, combining high adsorption energy, low diffusion barriers, low voltage, high specific capacity, and outstanding electrical conductivity.

Bismuth-based ternary chalcogenides Pt3Bi4X9 (X = S, Se) as promising thermoelectric materials

We present a theoretical investigation of thermoelectric transport properties of bismuth-based ternary chalcogenides Pt3Bi4X9 (X = S, Se), which has low thermal conductivity and promising zT as discovered in a recent experiment [Wang et al., J. Am. Chem. Soc. 146, 7352 (2024)], using density functional theory combined with the Boltzmann transport equation within rigid band approximation. We find that the high density of states of valence bands near the Fermi level yields high p-type Seebeck coefficient. The lower effective mass of electron in Pt3Bi4S9 leads to high mobility and long relaxation time, and hence the high n-type electrical conductivity. In contrast, the effective mass of electron is much higher than that of hole in Pt3Bi4Se9 due to the flatted conduction band, which in turn gives rise to higher p-type electrical conductivity. As a result, the p-type zT is much higher than n-type in Pt3Bi4Se9, with an optimal value of 0.5 at 300 K. Considering the experimental carrier concentration for Pt3Bi4S9 (−1.4 × 1019 cm−3) and Pt3Bi4Se9 (−0.898 × 1019 cm−3), calculated n-type zT at 773 K are 0.52 and 0.04, respectively, which are consistent well with the experimental values. Our calculations uncover the upper limit thermoelectric zT of Pt3Bi4X9 and also highlight them as promising thermoelectric materials.

Electrochemical Performance of MoB/Si3N4 Heterojunction as a Potential Anode Material for Li Ion Batteries.

In response to the current policy of high storage capacity, two-dimensional (2D) materials have revealed promising prospects as high-performance electrode materials. MoB, as a type of such material, is widely regarded as an anode candidate for Li-ion batteries due to its large specific surface area and abundant ion diffusion channels; the long-term cycling stability, however, is poor owing to material pulverization during the cycle. Therefore, MoB/Si3N4 heterojunction in this work is proposed as an anode material, with Si3N4 acting as a skeleton, maintaining the stability of the structure, while retaining the high energy storage properties of MoB as well. In addition, a certain built-in electric field is formed between them, which can play a role in regulating charge transfer, improving the ion transport channel, and accelerating the migration rate. Herein, the structural, electronic, and electrochemical properties are systematically investigated by first-principles calculations; the final results indicate that the heterojunction anode material does indeed have built-in electric fields, which promote the anode material to possess excellent electrical conductivity and outstanding electrochemical property. Meanwhile, the introduction of vacancy defects can bolster the diffusion kinetic performance of ion transport and greatly reduce the diffusion energy barrier of Li ions, which is conducive to the realization of rapid charge and discharge for the Li ion battery. Based on the synergistic effect of two single-component materials, the synthesized anode material displays a high theoretical capacity of 461 mAh/g, and the calculated open-circuit voltage is 0.66 V, within the range of the negative electrode criterion of 0-1 V, which can effectively play a role in preventing the formation of Li dendrites; these properties are comparable to other 2D anode materials as well. Given these intriguing properties, the MoB/Si3N4 heterojunction is an exceptional candidate for advanced LIB high-performance anode materials.

1T′-MoSP monolayer as an anode material for sodium-ion batteries with ultrahigh storage capacity and ultralow diffusion barrier

Sodium-ion batteries (SIBs) have gained significant attention due to the abundant availability and low cost of sodium. However, the search for high-performance anode materials remains a critical challenge in advancing SIB technology. Based on first-principles swarm-intelligence structure calculations, we propose a metallic 1T′-MoSP monolayer as an anode material that offers a remarkably high storage capacity of 1011 mA h g−1, an ultralow barrier energy of 0.04 eV, and an optimal open-circuit voltage of 0.29 V, ensuring high rate performance and safety. Additionally, the monolayer presents favorable wettability with commonly used SIB electrolytes. Even after adsorbing three-layer Na atoms, the 1T′-MoSP monolayer retains its metallic nature, ensuring excellent electrical conductivity during the battery cycle. These desirable properties make the 1T′-MoSP monolayer a promising anode material for SIBs.

A Geophysical Investigation in Which 3D Electrical Resistivity Tomography and Ground-Penetrating Radar Are Used to Determine Singularities in the Foundations of the Protected Historic Tower of Murcia Cathedral (Spain)

This study presents a procedure in which 3D electrical resistivity tomography (ERT) and ground-penetrating radar (GPR) were used to determine singularities in the foundations of protected historic towers, where space is limited due to their characteristics and location in highly populated areas. This study was carried out on the Tower of the Cathedral “Santa Iglesia Catedral de Santa María” in Murcia, Spain. The novel distribution of a continuous nonlinear profile along the outer and inner perimeters of the Tower allowed us to obtain a 3D ERT model of the subsoil, even under its load-bearing walls. This nonlinear configuration of the electrodes allowed us to reach adequate investigation depths in buildings with limited interior and exterior space for data collection without disturbing the historic structure. The ERT results were compared with GPR measurements and with information from archaeological excavations conducted in 1999 and 2009. The geometry and distribution of the cavities in the entire foundation slab of the Tower were determined, verifying the proposed procedure. This methodology allows the acquisition of a detailed understanding of the singularities of the foundations of protected historic towers in urban areas with limited space, reducing time and costs and avoiding the use of destructive techniques, with the aim of implementing a more efficient and effective strategy for the protection of other tower foundations.

Woody Encroachment Modifies Subsurface Structure and Hydrological Function

ABSTRACTWoody encroachment—the expansion of woody shrubs into grasslands—is a widely documented phenomenon with global significance for the water cycle. However, its effects on watershed hydrology, including streamflow and groundwater recharge, remain poorly understood. A key challenge is the limited understanding of how changes to root abundance, size and distribution across soil depths influence infiltration and preferential flow. We hypothesised that woody shrubs would increase and deepen coarse‐root abundance and effective soil porosity, thus promoting deeper soil water infiltration and increasing soil water flow velocities. To test this hypothesis, we conducted a study at the Konza Prairie Biological Station in Kansas, where roughleaf dogwood (Cornus drummondii) is the predominant woody shrub encroaching into native tallgrass prairie. We quantified the distribution of coarse and fine roots and leveraged soil moisture time series and electrical resistivity imaging to analyse soil water flow beneath shrubs and grasses. We observed a greater fraction of coarse roots beneath shrubs compared to grasses, which was concurrent with greater saturated hydraulic conductivity and effective porosity. Half‐hourly rainfall and soil moisture data show that the average soil water flow through macropores was 135% greater beneath shrubs than grasses at the deepest B horizon, consistent with greater saturated hydraulic conductivity. Soil‐moisture time series and electrical resistivity imaging also indicated that large rainfall events and greater antecedent wetness promoted more flow in the deeper layers beneath shrubs than beneath grasses. These findings suggest that woody encroachment alters soil hydrologic processes with cascading consequences for ecohydrological processes, including increased vertical connectivity and potential groundwater recharge.

On the Reliability of Constraining Surface Conductivity using Induced Polarization Measurements in Sedimentary Rocks

Summary Recent advances in understanding the induced polarization (IP) method have led to improvements in interpreting hydraulic properties from electrical measurements. Distinguishing the effect of surface conduction from conduction through the electrolyte filling the interconnected pore spaces has been an ongoing challenge in interpreting field-scale electrical resistivity datasets. Previously proposed mechanistic models have suggested that this limitation can be overcome by utilizing the coefficient that describes the ratio between IP measurements and surface conductivity. In this study, we examine this proportionality coefficient ($\mathcal{l}$) through the relationship between IP parameters (imaginary conductivity and normalized chargeability) and surface conductivity for a sample group of 98 sedimentary rocks, composed of sandstones, carbonates, and mudstones. A strong linear relationship is observed between the IP parameters and surface conductivity. However, values of $\mathcal{l}$ vary significantly across each sample group such that low-salinity estimates of formation factor (F) using the single universal estimate of $\mathcal{l}$ are poor. Estimates of F for a single rock type (sandstone, carbonate, or mudstone) are improved using $\mathcal{l}$ values unique to that rock type, although F estimates for mudstones show high sensitivity to changes in $\mathcal{l}$. Using $\mathcal{l}$ coefficients calibrated on a sample group with similar lithological properties to the investigated group moderately improves the estimation of F. Consistent with theory, no relationship is observed between the proportionality coefficient and the measured petrophysical parameters of the porous medium. Our results suggest that, although IP measurements provide a valuable field-scale proxy for surface conductivity, improving petrophysical predictions (i.e. in this case, estimating F) remains a challenge.

Geoelectrical resistivity and geochemistry monitoring of landfill leachates due to the seasonal variations and the implications on groundwater systems and public health

Understanding the seasonal variations in the landfill leachate plumes (LLPs) properties and complex connections between concentrations of leachate variability, and its environment is essential for environmental and public health management. This study explores the combined electrical resistivity (ER) data and physiochemical water analysis (PWA) coupled with the excavations to monitor the landfill physiochemical properties (LPPs) due to seasonal variations and their implications on environmental vital organs and public health. The variations in ER and LLP distributions across the overburdened top layer due to seasonal changes were examined. The low ER contrasts were encountered within the ranges of 1.5 Ωm – 19.0 Ωm which was mapped as LLP accumulated zones within the landfill, while high ER values varied between 15 Ωm – 260 Ωm off-the landfill extending beyond 15 m. The results of the PWA indicate high concentrations of heavy metals (HMs) such as iron (Fe), lead (Pb), zinc (Zn), and cadmium (Cd) decreasing with wet seasons and increasing with dry seasons. The overall high concentration of HMs in the LLPs was indeed varied between 9.81 ± 2.15–19.07 ± 3.68, while the electrical conductivity (EC) significantly increased from 17.99 ± 1.92 mg/L to 24.87 ± 3.31 mg/L towards the wet season. The increment and decrement encountered in the LPPs are due to seasonal variation and dilution. The order of decrement in the HMs in the LLPs treads as follows EC > Fe > Zn > Pb > Cd in values, respectively. The near-surface EC aligned well with the ER results and boundaries of the waste disposal site, which was verified by the soil excavations. In addition, the ER method was extended beyond the landfill for adequate monitoring, identifying the subsurface layers, conductive shallow zones mapped as the zones of LLP accumulation, resistive deep and shallow zones mapped as the consolidated lateritic topsoil and crystalline basement rocks in some cases, and a dipping conductive lineament zones identified as fracture zones just before the crystalline basement. In conclusion, the ER technique reveals the vertical and horizontal extents of the LLP escapade, the PWA expressed the concentrations of HMs in the LLPs, heightening the implications on the environmental and human health. Finally, the combined techniques deployed for monitoring the physiochemical properties of LLPs due to seasonal variation and the impacts on the integrity of groundwater quality systems and public health inform sustainable waste management practices, which contributes significantly to the protection of groundwater resources and the development of effective strategies to safeguard groundwater systems and public health for present and future generations.

Conductive Biocomposite Made by Two-Photon Polymerization of Hydrogels Based on BSA and Carbon Nanotubes with Eosin-Y

Currently, tissue engineering technologies are promising for the restoration of damaged organs and tissues. For regeneration of electrically conductive tissues or neural interfaces, it is necessary to provide electrical conductivity for the transmission of electrophysiological signals. The developed biocomposite structures presented in this article possess such properties. Their composition includes bovine serum albumin (BSA), gelatin, eosin-Y and single-walled carbon nanotubes (SWCNTs). For the first time, a biocomposite structure was formed from the proposed hydrogel using a nanosecond laser, and a two-photon absorption cross section value of 580 GM was achieved. Increased viscosity over 3 mPa∙s and self-focusing with a nonlinear refractive index of 42 × 10−12 cm2/W make it possible to create a biocomposite structure over the entire specified area. The obtained electrical conductivity value was 19 mS∙cm−1, due to the formation of effective electrically conductive networks. For a biocomposite with a concentration of gelatin 3 wt. %, formed by low-energy near-IR pulses, the survival of Neuro 2A nerve tissue cells was confirmed. The obtained results are important for the creation of new tissue engineering structures and neural interfaces from a biopolymer hydrogel based on the organic dye eosin-Y and carbon nanotubes by two-photon polymerization.

Deep geophysical investigations (DERT and Seismic Reflection) to unravel the Ferrara urban area geology

Exploring the ‘fragile crust of our planet’ is crucial for human survival holding an immense social and economic significance. Therefore, innovative approaches become of utmost importance for obtaining precise subsoil models in urban areas making the latter more resilient to natural disasters. Due to logistic issues and a high level of anthropogenic disturbance and related background noise, urban areas are usually intrinsically more problematic for applying geophysical prospecting methods. This work presents the results obtained by Deep Electrical Resistivity Tomography and P wave Seismic Reflection surveys performed along the Ferrara, north Italy, city walls documenting the adaptability of the geophysical surveys and how it is possible to obtain high-quality electrical resistivity and seismic data even in complex urban settings. The joint interpretation of geoelectrical and seismic data fully integrated with tectonic, geological and hydrogeological information allowed to reconstruct the stratigraphic evolution down to a depth of about 1.5 km. These results highlight the occurrence of a syndepositional Quaternary tectonic tilting associated with the growth of a fault-propagation fold.