Electrical Conductivity Values Research Articles

Groundwater Quality Status of the Parambikulam Aliyar Palar Basin, Tamil Nadu, India Using RS and GIS Techniques

The dependency of ground water is rising day by day. The ground water gets recharged mainly through rainfall. Thirty five water samples were collected from Parambikulam Aliyar Palar basin from open wells, bore wells and dug cum bore wells and analysed for chemical properties such as pH, Electrical Conductivity, cations and anions for two years duration (2020 and 2021) at three months interval (summer, winter, southwest monsoon, northeast monsoon) and analysed for the quality parameters. T Electrical conductivity values were ranged from 0.3 to 5.19 dsm-1, 0.29 to 6.80 dsm-1 0.3 to 6.84 dsm-1 and 0.64 to 4.17 dsm-1 during south west, north east, winter and summer seasons of 2020, respectively. The salt content was slightly increased during winter and summers seasons as compared to south west and north east. he samples were classified under USSL classification. Most of the samples come under medium salinity class (C2) (48.57%) followed by low salinity class (C1), high salinity class (C4) and very high salinity class (C3) with 28.57, 14.29 and 8.57 per cent respectively in all the seasons. Majority of the samples exhibit there is no permeability hazard. Salinity persists in the basin and possibility of salt accumulation in irrigation pipes observed from LSI values. Using remote sensing and GIS technique, the mapping was done for the groundwater quality of PAP basin. The variations in the ground water quality of the basin are directly positively correlated with rainfall pattern and geology of the basin. For effective utilization of saline water in the basin, management strategies were formulated and field experiments were conducted in the farmer’s holdings in the sampling area of the basin.

Frequency-dependent dielectric, electric modulus, and ac conductivity features of Au/n-Si Schottky diodes (SDs) with PVC and (PVC:Graphite/Graphene-Oxide) interlayer

To determine the interlayer effect on dielectric features and conductivity, Au/n-Si (S0), Au/PVC/p-Si (S1), and Au/PVC:Gt-GO/p-Si (S2) type SDs were grown onto the same n-Si wafer and their admittance measurements performed between 100 Hz and 1 MHz. The observed decrease in C and G/ω values as frequency increases shows that the charges at the interface-states (N ss) can easily follow ac-signal and supply an excess capacitance and conductance at lower frequencies. Using C and G/ω data at 1.5 V, the dielectric-constant (ϵ′), dielectric-loss (ϵ″), and loss-tangent (tan δ) were obtained as a function of frequency. To determine the relaxation processes in (PVC:Gt-GO) nanocomposite, complex-dielectric (M′ and M′′) formalism was also explored in the whole frequency range. The value of ac electrical conductivity (σ ac) remained independent of frequency until 0.1 MHz and then started to increase exponentially which corresponds to dc and ac conductivity. As compared to S1 and S2 with So SD, the conductivity and ϵ′ values increase due to the PVC and (PVC:Gt-GO) interlayer. The Ln(σ ac)-Ln(ω) plots were also drawn to analyze the conduction process and their slopes were found as 0.09, 0.39, and 0.58 for S0, S1, and S2 SD, respectively. These results show that the interaction and trap levels of the electron–hole pairs at lower frequencies, as well as from the well-localized relaxation mechanism at higher frequencies.

Thermoelectric and photovoltaic properties of 12-BaBi2S4

In this report, we have investigated the structure and properties of the 12-BaBi2S4. A single crystal X-ray diffraction study shows that the 12-BaBi2S4 crystallizes in the hexagonal crystal system (space group = P63/m) with refined lattice parameters of a = b = 25.2687(10) Å, c = 4.1859(2) Å, and formula unit = Z = 12 at room temperature. The structure contains fifteen crystallographic independent sites, including three Ba, four Bi, and eight types of S atoms. A phase pure polycrystalline sample of 12-BaBi2S4 was synthesized by heating stoichiometric amounts of BaCO3 and Bi2O3 under a CS2 atmosphere. The phase pure sample is found to be a semiconductor with a direct bandgap of 1.3(1) eV. The polycrystalline 12-BaBi2S4 exhibits ultra-low thermal conductivity values, varying from 0.47 Wm−1K−1 at 323 K to 0.43 Wm−1K−1 at 773 K. The sample shows high values of the Seebeck coefficient (S = −300 μV/K to −210 μV/K) in the 323 K–773 K range with poor electrical conductivity values. The negative sign of the S implies that the sample is a n-type semiconductor. DFT studies of the 12-BaBi2S4 also predict semiconducting properties. We have explored the 12-BaBi2S4 sample for photovoltaic (PV) applications by fabricating a liquid junction solar cell, TiO2/CdS/12-BaBi2S4/Sn2−/S2−/MWCNTs@Ni, which delivered an efficiency enhanced by ∼12 % to the control cell based on sole CdS as the photo-sensitizer. Theoretical electronic structure calculations suggest the semiconducting nature of the 12-BaBi2S4 in agreement with the optical absorption and electrical resistivity studies.

Technical note: Two-component electrical-conductivity-based hydrograph separation employing an exponential mixing model (EXPECT) provides reliable high-temporal-resolution young water fraction estimates in three small Swiss catchments

Abstract. The young water fraction represents the portion of water molecules in a stream that have entered the catchment relatively recently, typically within 2–3 months. It can be reliably estimated in spatially heterogeneous and nonstationary catchments from the amplitude ratio of seasonal isotope (δ18O or δ2H) cycles of stream water and precipitation, respectively. Past studies have found that young water fractions increase with discharge (Q), thus reflecting the higher direct runoff under wetter catchment conditions. The rate of increase in the young water fraction with increasing Q, defined as the discharge sensitivity of the young water fraction (Sd*), can be useful for describing and comparing catchments' hydrological behaviour. However, the existing method for estimating Sd*, which only uses biweekly isotope data, can return highly uncertain and unreliable Sd* when stream water isotope data are sparse and do not capture the entire flow regime. Indeed, the information provided by isotope data depends on when the respective sample was taken. Accordingly, the low sampling frequency results in information gaps that could potentially be filled by using additional tracers sampled at a higher temporal resolution. By utilizing high-temporal-resolution and cost-effective electrical conductivity (EC) measurements, along with information obtainable from seasonal isotope cycles in stream water and precipitation, we develop a new method that can estimate the young water fraction at the same resolution as EC and Q measurements. These high-resolution estimates allow for improvements in the estimates of the Sd*. Our so-called EXPECT (Electrical-Conductivity-based hydrograph separaTion employing an EXPonential mixing model) method is built upon the following three key assumptions: We construct a mixing relationship consisting of an exponential decay of stream water EC with increasing young water fraction. This has been obtained based on the relationship between flow-specific young water fractions and EC. We assume that the two-component EC-based hydrograph separation technique, using the above-mentioned exponential mixing model, can be used for a time-source partitioning of stream water into young (transit times < 2–3 months) and old (transit times > 2–3 months) water. We assume that the EC value of the young water endmember (ECyw) is lower than that of the old water endmember (ECow). Selecting reliable values from measurements of ECyw and ECow to perform this unconventional EC-based hydrograph separation is challenging, but the combination of information derived from the two tracers allows for the estimation of endmembers' values. The two endmembers have been calibrated by constraining the unweighted and flow-weighted average young water fractions obtained with the EC-based hydrograph separation to be equal to the corresponding quantities derived from the seasonal isotope cycles. We test the EXPECT method in three small experimental catchments in the Swiss Alptal Valley using two different temporal resolutions of Q and EC data: sampling resolution (i.e. we only consider Q and EC measurements during dates of isotope sampling) and daily resolution. The EXPECT method has provided reliable young water fraction estimates at both temporal resolutions, from which a more accurate discharge sensitivity of the young water fraction (SdEXP) could be determined compared with the existing approach. Also, the method provided new information on ECyw and ECow, yielding calibrated values that fall outside the range of measured EC values. This suggests that stream water is always a mixture of young and old water, even under very high or very low wetness conditions. The calibrated endmembers revealed a good agreement with both endmembers obtained from an independent method and EC measurements from groundwater wells. For proper use of the EXPECT method, we have highlighted the limitations of EC as a tracer, identified certain catchment characteristics that may constrain the reliability of the current method and provided recommendations about its adaptation for future applications in catchments other than those investigated in this study.

Development of Microcontroller Based Water Quality Monitoring and Water Level Control Device

Access to clean and safe water is not only a fundamental human right but also a vital requirement for electronics industries, chemicals industries, pharmaceuticals, food and beverage production, fisheries and aquatic farming. This project addresses the pressing issue of water quality monitoring and efficient water usage within the context of these industries. The study's identification of problem areas for water quality can lead to more efficient interventions and solutions to safeguard the environment, and prevent waterborne diseases. This paper presents the design and implementation of microcontroller-based system for monitoring water quality and water level in the thank, the water in the thank is refilled when it goes beyond a set threshold with the aid of an automatic switch control. The system is a hybrid of 3 subsystems: a Water Level Checker, a Water Quality Monitoring System and an Automatic Switch control system. The Water level checker consists of Ultrasonic sensors. The Water Quality Monitoring system consists of pH sensors, TDS (Total Dissolved Solids) sensors and Turbidity sensors. The continuous (Analog) data from the water quality sensors used would be outputted via an LCD (Liquid Crystal Display). The Automatic Switch control system consists of 5v Relay modules and a 12v Pump that would automatically switch ON/OFF depending on the level of water in the tank. The values of EC (Electrical Conductivity) and TDS spike drastically to the introduction of salt from as low as 138 -906 for TDS and 0.34 – 2.04 for EC, signifying increase in water capacity of electrical conductivity. Temperature rise in the afternoon also increases TDS values from 142 for clean water to 920 for the salty water while it ranges from 138 for clean water to 906 for salt water at both morning and evening time. Pumping aspects of the system are triggered when water level in the thank falls below 10% and trips off when water level goes above 95% as programmed in the control unit. The developed system marks a significant achievement in water management and automation technology. integration of quality monitoring sensors has enabled real-time evaluation of water parameters that holds potential for applications in environmental monitoring, ensuring safe drinking water, and safeguarding aquatic ecosystems. The automated switch control mechanism responds dynamically to water levels, enabling the system to trigger actions such as pump activation or filling processes based on predefined thresholds.

Optimization of an innovative hybrid approach ZnO-Doped PVP nanofibers for electrical devices applications

The solid solution of pure ZnO nanoparticles and doped Polyvinylepyrrolidone (PVP) green hybrid nanomaterial’s synthesized by using the electro spinning method. The synthetic polymer matrix nonwoven fibrous mats containing innovative properties are shown to shrink and encapsulated the zinc oxide materials to change the surface morphology when the concentration of PVP is increased from 1 % to 2 % dopants. The crystalline nature and morphological studies were examined by using x-ray diffraction and a scanning electron microscope. The average crystallite sizes of easily formed ZnO nanoparticles and nanorods that are 21 nm and 62 nm respectively. Moreover, the electrical and optical properties of the fibrous mesh were determined by using electrical impedance analyzer. The electrical conductivity values were measured in the pure ZnO nanoparticles in contrast to the doped ZnO/PVP. The tangent loss, dielectric constant, capacitance and relaxation time values are revealed in this study. All the characterization has been carried out at room temperature. The relaxation time for 1 %, and 2 % ZnO/PVP is (0.8 ns) and (0.79 ns) respectively which is suitable for the application of trigger using devices. The overall findings of this study implemented in a wide range of technologies i.e. photonics, electronics and super capacitor devices etc.

Enhancing the Conductivity and Dielectric Characteristics of Bismuth Oxyiodide via Activated Carbon Doping.

Activated carbon/BiOI nanocomposites were successfully synthesized through a simplistic method. The produced composites were then characterized using XRD, TEM, SEM-EDX, and XPS. The results showed that BiOI with a tetragonal crystal structure had been formed. The interaction between activated carbon and BiOI was confirmed via all the mentioned tools. The obtained nanocomposites' electrical conductivity, dielectric properties, and Ac impedance were studied at 59 KHz-1.29 MHz. AC and dc conductivities were studied at temperatures between 303 and 573 K within the frequency range of 59 KHz-1.29 MHz. The 10% activated carbon/BiOI nanocomposite possessed dc and AC conductivity values of 5.56 × 10-4 and 2.86 × 10-4 Ω-1.cm-1, respectively, which were higher than BiOI and the other nanocomposites. Every sample exhibited increased electrical conductivity values as the temperature and frequency rose, suggesting that all samples had semiconducting behavior. The loss and dielectric constants (ε' and ε″) also dropped as the frequency increased, leading to higher dielectric loss. The Nyquist plot unraveled single semicircle arcs and a decreased bulk resistance, indicating decreased grain boundary resistance. Consequently, the electrical characteristics of BiOI, 1C/BiOI, 5C/BiOI, and 10C/BiOI implied their applicability as dielectric absorbers, charge-stored capacitors, and high-frequency microwave devices.

Thermoelectric, mechanical and electrochemical properties of pure single-phase FeSb

This study primarily focused on forming pure single-phase FeSb and explored its thermoelectric, mechanical, and electrochemical properties since no reports are available. The FeSb binary alloy has been synthesized through the vacuum melting method, and the phase formation has been confirmed through powder X-ray diffraction (PXRD). The PXRD results show that the synthesized FeSb binary alloy belongs to the hexagonal crystal structure with space group P63/mmc, which coincides with ICSD no. 53971. The pure single phase has been formed by creating a deficiency of 10 % in antimony. The High-Resolution Scanning Electron Microscopy (HR-SEM) and Energy Dispersive X-ray (EDX) analysis have been used to identify the pure single-phase and various elemental components of the hot-pressed pellet of FeSb0.9. The atomic wt.% of iron (Fe) and antimony (Sb) have been identified through EDX spectral analysis. The highest Seebeck coefficient value of -5.4 μV/K is achieved at 497 K, and the lowest electrical conductivity value of 24049 S/m is achieved at 447 K. The hardness of the material is found to be 6.076 GPa, which is much more sufficient for thermoelectric material during industrial handling. The magnetic characteristics of the prepared pure phase FeSb compound have also been measured by Vibrating Scanning Magnetometer (VSM) analysis, which has a weak ferromagnetic nature. Furthermore, three electrodes were employed to study the electrochemical properties, and the alloy has attained the appreciable specific capacitance of 169.5 F/g at 2 A/g. .

Polyaniline impact on graphitic C3N4’s structural and physicochemical properties for high stability energy storage systems: Practical and theoretical studies

Polyaniline (PANI), and graphitic C3N4 (GCU) have a significant research consideration owing to their properties. Accordingly, in the current study, PANI, GCU, and their composite (PANI@GCU) are synthesized through aniline chemical polymerization in the presence of C3N4. Materials characterizations are done using X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR). SEM images demonstrate that the PANI layers cover the surface of the GCU. Samples are studied through dielectric and electrochemical analysis. The electrical conductivity value shows a conductivity increment in the order: PANI@GCU > PANI > GCU. The PANI@GCU composite sample exhibits a bulk conductivity of 23 S/m at 10 MHz frequency. It also has a 584 F/g specific capacitance with 96.7 % stability after 1000 cycles at 1 A/g. The results of PANI@GCU supercapcitance performance are supported with molecular modelling that shows the interaction between GCU and PANI through the elongation of C-N bond of PANI beside of GCU layer bending to create arc and arrow structure. The structure of PANI@GCU has a lower band gap (ΔEgap) than PANI, and GCU separately which agrees with the enhancement of the conductivity of the composite than its constituent.

Giant Seebeck coefficient in SnTe thin films grown by thermal evaporation using layered structure engineering

In this work, we have reported a giant Seebeck coefficient (8033 µV/K) in SnTe thin films by controlling the layered structure using post growth annealing technique. The samples used in the current study were synthesized using a vacuum tube furnace having an evaporation temperature 700 °C, base pressure 180 m Torr and source to substrate distance 7 cm. Sn and Te metal powders with an equal weight ratio were evaporated on the glass substrate to form SnTe composite. Post-growth annealing in vacuum environment was performed for different time’s duration of 1–4 h with a step of one hour. XRD analysis reveals six diffraction peaks for all samples, which correspond to different crystal planes of SnTe structure. Raman spectra exhibit the presence of specific vibrational modes associated with SnTe. Using the giant value of Seebeck coefficient and moderate electrical conductivity, a strong power factor value of 8.1 × 10−3 W m−1 K−2 was observed for optimized sample (annealed for 3 h). The strongest values of Seebeck coefficient and power factor are supposed to be the layered structure of SnTe thin films which was verified by the SEM images.

Characterization of physical and chemical properties of honey from Northeastern Anatolia of Türkiye

The aim of this study was to investigate the physical and chemical properties of natural highland honey produced in the northeastern Anatolia region of Turkey. In 2020, 24 honey samples collected and sold during the honey harvest season were purchased from local vendors. Moisture, color, acidity, pH, conductivity, diastase and invertase activity, C13, C13 protein-honey, C4 analysis and sugar components were analyzed in honey samples. The honey samples were found to contain 17.4% moisture. The mean invertase level were found to be 156.216 U/kg. The freshness and enzymatic activity of the honey were shown by the average diastase number of 12.8 DS. The mineral content and overall purity of the honey was indicated by an electrical conductivity value of 0.17 mS/cm. The average acidity value 15.9 meq/kg, fructose/glucose ratio 1.26% and the average color value 33 mm Pfund determined. The average sugar contents in the honey samples were as follows: fructose 37.4%, glucose 29.5%, sucrose 1.4%, turanose 1.8%, maltose 0.6%, isomaltose 0.2%, erlose 0.3%, trehalose 0% hybriditose 0% maltotriose 0% fructose+glucose. 66.9%, fructose/glucose 1.26, glucose/water 2.0. The mean difference between honey protein and honey delta C13 data is -0.58 and C4 sugar ratio is 0. In conclusion, valuable findings were obtained on the physical and chemical properties of honey from the northeastern Anatolia region of Turkey. Further research can build on these findings to explore the unique properties and potential benefits of honey from this region and contribute to its value and utilization in various industries.

Modification of Hilhorst model for saturated extract electrical conductivity estimation of coir using frequency domain reflectometry sensors – A laboratory study

Frequency domain reflectometry (FDR) sensors can measure moisture content and electrical conductivity (EC) of growing media, thus providing information for effective water and nutrient management of crops. FDR sensors generally provide the bulk EC (σb) value, which is different from the saturated extract EC (σe) values that most growers and practical studies generally use. To properly estimate σe of media, we modified the previous Hilhorst model that calculates pore water EC (σp) from FDR sensor readings. The 16 coir samples with four moisture and four EC levels were prepared, and their changes in the dielectric constant of bulk medium (εb), σb, and medium temperature from the FDR sensors were recorded and used for analysis. As a result, the εσb=0 (εb when σb is 0) of the coir used in this experiment was 1.64, which was much lower than the εσb=0 suggested for mineral soil (4.1), indicating that the medium-specific εσb=0 should be adjusted. Although σe value estimation through the Hilhorst model with adjusted εσb=0 improved, the values were still unreliable to represent the actual σe values (root mean square error, RMSE = 2.280, R2 = 0.30). To convert the σp derived from the Hilhorst model with adjusted εσb=0 to actual σe, the regression equation was applied as σe = 0.5381 × σp + 1.6493. The adjusted Hilhorst model could provide a more reliable σe estimation (RMSE = 0.929, R2 = 0.62). These results indicate that proper adjustment of εσb=0 for the specific medium is necessary, and adjusting the equation for converting σp into σe would be helpful to properly interpret the σb to practically utilize the FDR sensors for effective water and nutrient management.

Pengembangan roti berbahan pati jagung dengan modifikasi enzimatis & pemanas ohmik (Kajian: pengaruh variasi tegangan dan transglutaminase terhadap karakteristik produk) [Development of corn starch-based bread with enzymatic modification & ohmic heating: study effect of voltage and transglutaminase variations on product characteristics]

The main challenges in producing gluten-free bread are closely related to its development, texture, and nutrition. This research consisted of 2 stages.  Stage 1 was aimed to determine the effect of voltage variations (70 V, 80 V, 90 V, 100 V, 110 V, 120 V, and conventional baking as a control) on bread characteristics and process parameters. The experiment was arranged as non-factorial in a completely randomized design with 3 replications. The best results of the first stage were applied in stage 2, aimed to determine the effect of various concentrations of TGase (0, 0.5, 1, 1.5, 2, and 2.5%). The data were processed using analysis of variance, then further tested using Tukey's at the 5% level. The 120 V voltage gradient treatment was found to be the best treatment. It shows specific volume 3.17±0.17 cm3/g, baking loss 14.58±1.50%, brightness 50.97±3.27, hardness 3.76±0.11, cohesive 0.34±0.03, pore density 84±2.52. In addition, baking at a higher voltage level increased the temperature rate and electrical conductivity. The 120 V voltage treatment shows the time required to reach a maximum temperature of 97°C was 3 minutes 5 seconds, and an electrical conductivity value of 0.26-0.51 S/m. Based on the TGase treatment, it was found that when bread dough was applied with a higher TGase concentration, the specific volume, hardness, chewiness, resilience, cohesiveness and springiness, average pore size, and pore porosity of the bread increased.

Mamdani-type fuzzy inference system for irrigational water quality

This paper aims to evaluate the quality of groundwater resources used for irrigation purposes using a Mamdani-type fuzzy inference system (MFIS). The MFIS is used to resolve ambiguities and uncertainties in economic, social, and natural systems and also facilitates the capture of expert knowledge in ways similar to human reasoning and thought processes. In this study, 20 groundwater samples were collected from various locations within the Mayiladuthurai district, Tamil Nadu, India, between January 2016 and December 2019. These samples underwent physical and chemical analyses to assess the suitability of the collected water resources for irrigation. The analysis utilizes the Mamdani Fuzzy Inference System, which combines values of Electrical Conductivity (EC) and Sodium Adsorption Ratio (SAR). Additionally, methods from the US Salinity Laboratory Staff were also employed. Ultimately, the groundwater quality in Mayiladuthurai is graded for irrigation use by this method. The results indicate that the MFIS reduces imprecision and uncertainty in data handling through the fuzzy membership function. The comparison of irrigation suitability results clearly demonstrates that the proposed MFIS method offers an improved assessment of the irrigation water quality level of the studied groundwater resources.

Crystallographic texture evolution in hot-press sintered tungsten heavy alloy with the effect of niobium (Nb) addition

This study examines the impact of niobium on the crystallographic texture evolution and grain boundary distribution of hot press sintered tungsten heavy alloy (W-4.9Ni-2.1Cu). EBSD analysis was used to examine the evolution of crystallographic texture and grain boundary character distribution in sintered compacts. The important findings of this study depict that cubic texture component {001} <111> were evolved in niobium unalloyed compacts due to the solidification of atoms aligned in a specified preferred orientation. Besides, it reveals the weakness in the cubic texture in niobium alloyed compacts due to the recrystallization followed by sub structural recovery occurrence during sintering. In addition, an increase in CSL fraction in niobium alloyed compacts illustrates the dominance of surface diffusion during sintering caused by the grain refinement attributed from the niobium enrichment at the tungsten-binder interface. Metallographic studies showed that the niobium concentration increment in WHAs has concomitant effect with sintered compacts' properties. A W-4.9Ni-2.1Cu-1 Nb alloy achieved the highest values for micro-hardness (432 HV0.5), electrical conductivity (23.74 % of IACS), and relative density (99.90 %).

Performance of vertical flow constructed wetland for the treatment of effluent from a brassware industry in city of Fez, Morocco: a laboratory scale study

Brassware industry constitutes the second most polluting industrial sector in Fez city, Morocco, owing to its high heavy metal load. The aim of this study is to examine and evaluate the performance of vertical flow constructed wetlands in treating brassware effluents using various plant species. Ten treatment systems were planted with four types of plants: Chrysopogon zizanioides, Typha latifolia, Phragmites australis, and Vitex agnus-castus, while another system remained unplanted. These systems underwent evaluation by measuring various parameters, including pH, electrical conductivity, suspended solids, chemical oxygen demand, biological oxygen demand, sulfates, orthophosphates, total Kjeldhal nitrogen, ammonium, nitrates, nitrites, and heavy metals such as silver, copper, and nickel, using standard methods over of ten weeks. The results obtained demonstrate effectiveness of these systems. When planted with Ch. zizanioides, the systems achieved elimination rates of 83.64%, 98.55%, 91.48%, 86.82%, 80.31%, 96.54%, 98%, and 98.82% for suspended solids, ammonium, nitrites, BOD5, sulfates, orthophosphates, silver, and nickel, respectively. System with V. agnus-castus showed significant reductions in nitrate and copper, with rates of 84.48% and 99.10%, respectively. Considerable decrease in pH and electrical conductivity values was observed in all systems, with a notable difference between planted and control systems regarding effectiveness of treatment for other parameters.

PAN-based fiber-reinforced carbon-carbon composites for improved fire retardancy and thermal and electrical conductivities for harsh environments

Carbon-carbon (C-C) fiber composites are a new class of materials that are used in various industries due to their exceptional chemical, thermal and electrical conductivities properties. In this study, carbon-carbon fiber composites were manufactured where polyacrylonitrile (PAN) powder was dissolved in dimethylformamide (DMF) solution, and carbon fibers with desired concentrations (20–80 wt%) were immersed into this solution as reinforcement through evaporation and solidification. The PAN-fiber systems were then stabilized at 250–270°C for 120 min in the air and subsequently carbonized at 650, 750, and 850°C for 60 min in the presence of argon gas to obtain the desired C-C fiber composites. Thermogravimetric analysis (TGA) results showed that the carbonized samples had a small weight loss of 2.5%, while actual and oxidized samples had more weight loss. Moreover, the carbonized sample surface was more hydrophobic compared to other samples due to the carbon presence and surface texture changes. Fourier-Transform Infrared (FTIR) spectroscopy peaks showed the presence of different functional groups of PAN before oxidation and carbonization, but those peaks disappeared after oxidation and carbonization. The developed carbon-carbon composite passed the UL94 vertical flame retardancy testing with a V-0 rating. Surface smoothness, proper matrix and reinforcements bonding were confirmed by scanning electron microscopy (SEM) results and the manufactured composite properties changes were validated by the confocal microscopy images. The carbon-carbon fiber composite achieved an electrical conductivity value up to 4.75 × 103 S/m after the carbonization process. The excellent thermal, chemical, and electrical properties of these composites can be useful for numerous industrial applications in different extreme environments.

Assessment of Reclaimed Mined Area of Sahastradhara, Dehradun by Soil and Vegetation Analysis

This study investigates the impact of forest area mining on reclaimed limestone mined areas in Sahastradhara, Uttarakhand, India. Initiated in 1989-90, eco-restoration efforts aimed at rehabilitating the mined areas resulted in restoration ages of 25, 24, and 23 years across different sites. The study comprehensively examined vegetation and soil physicochemical properties at various depths, revealing the dominance of species like Murrayakoenigii, Acacia catechu, Vitex negundo, Eupatorium adenophorum, Grevillea robusta, and Lantana camara. Soil analyses unveiled variations in moisture content, bulk density, and coarse fragment percentage across the sites, a rise in organic carbon, phosphorous, and nitrogen levels, showcasing soil improvement post-restoration. Correlation analyses unveiled interrelationships between soil properties, emphasizing the importance of organic matter in influencing soil acidity. Vegetation analyses at different sites revealed evolving plant communities, with prominent species contributing to the ecological richness. The Importance Value Index (IVI) and Shannon Weiner Index (H') provided insights into species dominance and biodiversity. The results showed that the soil pH was slightly basic, and the available phosphorus and nitrogen levels were within the optimal range for plant growth. However, the bulk density and electrical conductivity values were higher than the recommended range. This study contributes valuable insights into the intricate interplay between mining activities, vegetation dynamics, and soil health, guiding future ecological restoration endeavors in similar contexts. The study concluded that the eco-restoration work carried out in the area has been successful in restoring the vegetation, but further assessment is required to ensure the long-term success of the restoration efforts.

Delineation of Groundwater Potential Zones for Sustainable Development and Planning using AHP and GIS Techniques in the Coal Mining Province of Mahan River Catchment Area

The present research aims to address the drinking water crisis in the Mahan River catchment area resulting from the disruption of groundwater availability due to extensive coal mining. The study uses GIS-based Multi-Criteria Decision Analysis (MCDA) to map the groundwater potential of the area by analysing several factors that affect groundwater availability, including rainfall, water depth, geomorphology, geology, soil, land-cover/land-use, and topographic characteristics derived from DEM. The groundwater potential map created using the MCDA technique classified the area into low, moderate, and high groundwater potential zones. The map was validated and verified using water table depth and electrical conductivity values available in the region, indicating that it can be used to identify groundwater recharging sites. The study’s results show that about 30% of the area has high groundwater potential, and more than 45% of the area has moderate groundwater potential. The information derived from the study can be used for sustainable management and proper planning of groundwater resources in the Mahan River catchment area. Overall, the study presents a useful approach to address the groundwater depletion problem resulting from coal mining activities in the Mahan River catchment area.

Isoflavone profile and soybean quality: Effects of genotype, cultivation environment and storage

The interaction between soybean genotypes and environmental conditions alters the chemical and phytochemical composition of soybeans. These changes influence the quality of soybeans during storage. Therefore, the study analyzed the influence of soybean genotypes (BMX ALVO RR, DM 57I52RSF IPRO, BRS 5601 RR, and 95r51), cultivation environment (Bagé, Cachoeira do Sul, Vacaria, and São Luiz Gonzaga), and storage time (0, 6, 12 months) on quality parameters and the isoflavone profile of soybeans. The analyses performed included titratable acidity, soluble protein, germination, electrical conductivity, soybean defects, colorimetric profile, and isoflavone profile. The Vacaria environment showed the lowest values for acidity (0.86–0.91%), lipase activity (6.14–14.2%), electrical conductivity (194.5–335.0 μS/cm), and fermented grains (0.45–1.4%) at the end of storage, regardless of the analyzed genotype, demonstrating to be a suitable environment for the cultivation of these genotypes. Additionally, the highest concentrations of isoflavones were also detected in the genotypes cultivated in Vacaria at the beginning of storage (2205.0–2983.8 μmol/g). Analyzing all the results, the 57i52RSF genotype cultivated in Vacaria showed the best quality during storage. On the other hand, the 95r51 genotype exhibited low quality during storage, especially when cultivated in São Luiz Gonzaga.