Salinity intrusion is one of the most serious consequences of climate change coupled with rising sea level that significantly affects agricultural activities in many parts of the world. This phenomenon has increasingly become more serious and frequently occurred in the Mekong Delta of Vietnam. As a result, Vietnam has been ranked among top five countries where have been devastatingly impacted by climate change, in particular, its Tra Vinh Province characterized by coastal plain and alluvial deposit. In addition, this area is of the tropical monsoon zone of long rainy season with source of salt brought from the sea by the tides and sea level rise. Regions that are contaminated by salt are located in lowland and often suffer from floods linking to tidal effects with salty water from river systems and channels. Soil salinity evaluation is critical for coastal protection, restoration, and agricultural planning since it can be considered as an agricultural indicator to evaluate quality of soil. Here, we attempt to estimate the soil salinity in Tra Vinh Province, in the Mekong Delta of Vietnam. Landsat 8 OLI images are utilized to derive indices for soil salinity evaluation including single bands, Vegetation Soil Salinity Index (VSSI), Soil Adjusted Vegetation Index (SAVI), Normalized Difference Vegetation Index (NDVI), and Normalized Difference Salinity Index (NDSI). Subsequently, satistical analysis between soil salinity, electrical conductivity (EC, dS/m), and environmental indices derived from Landsat 8 OLI image is performed. Results indicate that spectral value of Near Infrared (NIR) band and VSSI are highly correlated with EC (R2 = 0.7779 and R2 = 0.6957, respectively) in comparison with the other indices. Comparative results show that soil salinity derived from Landsat 8 is consistent with in situ data. Findings of this study demonstrate that Landsat 8 OLI images reveal a high potential for spatiotemporally monitoring the magnitude of soil salinity at the top soil layer. Outcomes of this study are useful for agricultural activities, planners, and farmers by providing the base map of soil salinity contamination for better selection of accomodating crop types to reduce economical lost in the context of climate change. Our proposed method that estimates soil salinity using satellite-derived variables can be applied in the other regions.

Polymer nanocomposites are composed of polymer materials reinforced with nano fillers. In the present study the effective thermal conductivity of the composites filled with nanofillers has been investigated using commercially available finite element software ABAQUS 6.11. The nanofillers used were alumina particles and multi-walled carbon nanotubes (MWNTs) and the matrix was considered to be made of epoxy. For the analysis 2D and 3D Representative Volume Elements (RVEs) were generated using Random Sequential Adsorption (RSA) algorithm using MATLAB and Python scripts. Thermal conductivity was found out for 2D and 3D RVEs for different area and weight fractions respectively. Two different shapes of the alumina nanoparticles were considered: spherical (circular) and ellipsoidal (elliptical) for 3D (2D) analysis. It was found that the thermal conductivity was increased with the addition of nanofillers. The increase in thermal conductivity was approximately same for both types of inclusions at corresponding area or weight fractions in 2D or 3D analysis. The results showed that addition of MWNTs to the composites lead to a significant increase in thermal conductivity than spherical or ellipsoidal inclusions.

A simple and effective surface modification of polyester fabrics with sulfuric acid to improve the interfacial deposition of polypyrrole was presented in our work. A range of sulfuric acid concentrations were analyzed by studying water contact angle. Effect of sulfuric acid modification on the deposition of polypyrrole was investigated by sheet resistance and color depth of fabric samples. Polyester fabrics coated with polypyrrole layer were confirmed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), X-Ray diffraction spectra (XRD), Fourier transform infrared spectroscopy (FTIR). XPS showed that sulphur containing functional groups were obviously appeared on the polyester fiber surface after modification, which were advantageous to promote the deposition of polypyrrole onto polyester fabrics. The improved deposition increased electrical conductivity of fabric samples.

When focusing on materials science in civil engineering, the current trend is to investigate the use of innovative solutions in order to enhance thermal and energy performances. This trend is amplified with the need for a sustainable development strategy for the construction sector. This paper assesses the integration of a Phase Change Material (PCM) in cement intended for building construction. The key characteristic of PCMs is their capacity to absorb energy and restore it. In building construction, this feature could be harnessed to save energy by incorporating PCMs in the materials used. In this study, passive integration of PCM in cement was tested and thermal properties of such an integration was assessed. The results provide insights into how PCMs affect cement as part of the concrete mixture, thus identifying the contribution of PCM-based cements in concrete mixtures.

Channel bends are one of the most important characteristic features of natural streams. These bends often create the conditions for a hyporheic zone, which has been recognized as a critical component of stream ecosystems. The streambed vertical hydraulic conductivity (K_v), vertical hydraulic gradient (VHG) and Darcian flux (DF) in the hyporheic zone were estimated at 61 locations along a channel bend of the Beiluo River during July 2015 and January 2016. All the streambed attributes showed great spatial variability along the channel bend. Both upward fluxes and downward fluxes occurred during the two test periods, most of studied stream sections were controlled by downwelling, indicating stream water discharge into the subsurface. The average downward flux was higher at the downstream side than at the upstream side of the channel bend, especially in July 2015. The distribution of streambed sediment grain size has a significant influence on the variability of K_v; high percentages of silt and clay sediments generally lead to low K_v values. Higher K_v at the depositional left bank at the upstream site shifted toward the erosional right bank at the downstream site, with K_v values positively correlated with the water depth. This study suggested that the variabilities of K_v and VHG were influenced by the stream geomorphology and that the distribution of K_v was inversely related, to a certain extent, to the distribution of VHG across the channel bend. K_v and VHG were found to have opposite effects on the DF, and the close relationship between K_v and DF indicated that the water fluxes were mainly controlled by K_v.

The main objective of this communication is to describe the ‘Global Salt Cycle’. Giant salt accumulations are commonly found along continental margins of former rifts. The first stage in the accumulation process is saturation of newly formed oceanic crust with seawater. Final mobilisation and accumulation of the salts occurs during rifting, localised in the vicinity of relict subduction zones. Oceanic crust is created along the spreading ridges in the deep oceans of the Earth. It exchanges mass and energy with seawater in hydrothermal circulation cells that penetrate deep into the new and fractured crust. Water-rock interactions include the formation of hydrated and hydroxylated minerals, e.g., serpentinites and clay minerals. By incorporating hydroxyl groups and water in their crystal lattices, the salinity of remaining brines increases. Subduction of oceanic crust and serpentinised lithosphere transports water, hydrated minerals, and marine salts deep into the crust and mantle. Upon pressurisation and heating of the subducting slab, different parts of this water are expelled at different depths/temperatures. The resulting fluids will contain salts brought in with the slab, as well as new salts formed by water-rock interaction. The combination of elevated pressures and temperatures, water, salinity, and CO2, create permeability in the normally impermeable, peridotitic mantle, by altering the fluid-rock dihedral angles of mineral grains. This P/T-determined intergranular permeability allows ascent of saline fluids, under lithostatic pressure, within the mantle wedge, or the slab itself. The fluids produce a mechanically weakened and buoyant zone within the mantle wedge due to high pore pressure between mineral grains and reduced mantle density. During the lifetime of a subduction zone, a substantial accumulation of saline fluids within the mantle wedge and crust, is evident. Deep, fluid reservoirs accumulate between the subduction trench and the volcanic front. They may exist for hundreds of millions of years, even after the extinction of the subduction zone. Saline fluids may escape to the surface along deep faults, due to overfilling of available pores/fractures. Fluids within the mantle wedge may form rock melts or exist as supercritical, mineral rich fluids. The combination of reduced pressure due to rifting, and a saline and buoyant mantle, creates a mantle circulation that brings the accumulated, saline fluids, to crustal levels. Salts will therefore accumulate during initial stages of rifting as a result of massive fluid expulsion, phase change and boiling of mantle fluids. No extra energy is required to produce phase change and boiling. The result is formation of solid salts or dense brines/slurries invading fractured crustal rocks, or escaping to the surface/seabed. This process may take place both before and after the sea has invaded a continental rift.

In this paper, the effect of microstructure on the thermal conductivity of plasma-sprayed Y₂O₃ stabilized ZrO₂ (YSZ) thermal barrier coatings (TBCs) is investigated. Nine freestanding samples deposited on aluminum-base superalloy are studied. Cross-section morphology such as pores, cracks, m-phase content, grain boundary density of the coated samples are examined by scanning electron microscopy (SEM) and electron back-scattered diffraction (EBSD). Multiple linear regressions are used to develop quantitative models which describe the relationship between the particle parameters, m-phase content and the microstructure such as porosity, crack-porosity, the length density of small-angle-crack and the length density of big-angle-crack. Moreover, the relationship between microstructure and thermal conductivity is investigated. Results reveal that the thermal conductivity of the coating is mainly determined by the microstructure and grain boundary density at room temperature (25 ℃) and by the length density of big-angle-crack, monoclinic phase content and grain boundary density at high temperature (1200 ℃).

Solvent-free, single-ion conducting electrolytes are sought after for use in electrochemical energy storage devices. Here, we investigate the ionic conductivity and how this property is influenced by segmental mobility and conducting ion number in crosslinked single-ion conducting polyether-based electrolytes with varying tethered anion and counter-cation types. Crosslinked electrolytes are prepared by the polymerization of poly(ethylene glycol) diacrylate (PEGDA), poly(ethylene glycol) methyl ether acrylate, and ionic monomers. The ionic conductivity of the electrolytes is measured and interpreted in the context of differential scanning calorimetry and Raman spectroscopy measurements. A lithiated crosslinked electrolyte prepared with PEG₃₁DA and STFSI monomers is found to have a lithium ion conductivity of 3.2 × 10^-6 and 1.8 × 10⁻⁵ S/cm at 55 and 100 °C, respectively. The percentage of unpaired anions for this electrolyte was estimated at about 23% via Raman spectroscopy. Despite the large variances in metal cation – STFSI binding energies as predicted via DFT and large variations in ionic conductivity, STFSI-based crosslinked electrolytes with the same charge density and varying cations (Li, Na, K, Mg, and Ca) were estimated to all have unpaired anion populations in the range of 19 to 29%.

As the interface between human and machine becomes blurred, hydrogel incorporated electronics and devices have emerged to be a new class of flexible/stretchable electronic and ionic devices due to their extraordinary properties, such as soft, mechanically robust and biocompatible. However, heat dissipation in these devices could be a critical issue and remains unexplored. Here, we report the experimental measurements and equilibrium molecular dynamics simulations of thermal conduction in polyacrylamide (PAAm) hydrogels. The thermal conductivity of PAAm hydrogels can be modulated by both the crosslinking density and water content in hydrogels. The crosslinking density dependent thermal conductivity in hydrogels varies from 0.33 to 0.51 Wm^-1K^-1, giving a 54% enhancement. We attribute the crosslinking effect to the competition between the increased conduction pathways and the enhanced phonon scattering effect. Moreover，water content can act as filler in polymers which lead to nearly 40% enhancement in thermal conductivity in PAAm hydrogels with water content vary from 23 to 88 wt%. Furthermore，we find the thermal conductivity of PAAm hydrogel is insensitive to temperature in the range of 25 ^oC – 40 ^oC. Our study offers fundamental understanding of thermal transport in soft materials and provides design guidance for hydrogel-based devices.

The performance of ground heat exchangers systems depends on the knowledge of the thermal parameters of the ground like thermal conductivity, thermal capacity and diffusivity. The knowledge of these parameters often requires quite accurate experimental analysis, known under the name of Thermal Response Test (TRT). In this paper, after a general analysis of the various available types of TRT and the study of the theoretical basics of the method, the perspective of the definition of a simplified routine method of analysis based on the combination of a particular version of TRT and the routine geotechnical tests for the characterization of soil stratigraphy and of the ground characteristics, mandatory before the construction of a new buildings, even if limited to quite short drilling depth (lower than 30 m). The idea of developing TRT in connection with geotechnical test activity has the objective of promoting a widespread use of in-situ experimental analysis and of reducing TRT costs and time duration of the experimental analysis. The considerations exposed in the present paper lead to reconsider a particular variety of the TRT in particular the version known as Thermal Response Test while Drilling (TRTWD).

The creation of hydrophobic, antifreeze and self-cleaning coatings is currently being pursued by many industrial sectors. The potential applications include the production of liquid and gas separators and filters, new materials, optical and microelectronic devices, and textiles and clothing. These coatings will also have wide application in the construction and automobile industries, shipping, and energy and agricultural sectors. The article proposes a simple approach to the creation of superhydrophobic and antifreeze coatings, by applying powder from multi-walled carbon nanotubes (MW-CNTs) to the sample surface. This method enables combination of the necessary factors: low surface energy, micro–nano-roughness and hierarchical multi-scale. The authors investigated the dependence of the wetting angle of such a surface on the time, type and degree of functionalization. The electrophysical properties of modified MW-CNTs were studied over wide frequency and temperature ranges. This method of obtaining hydrophobic coatings differs from currently available methods in that it is simpler to prepare, is of lower cost and has less environmental impact. The proposed approach can be used to create superhydrophobic coatings that have the additional function of removing static charge and therefore reducing surface heating, and which can be used in the field of energetics for protection against the freezing of wind turbine blades and aircraft surfaces.

Various type of soils have been identified based on their electrical and magnetic properties, especially with regards to peat soils. Peat soils are commonly considered as partly decomposed vegetation. In this study, electrical and magnetic properties have been used in K-means clustering to identify layers of peat soils. K-means clustering is a partitioning method that treats observations in the data. Data cores were obtained at every centimeter and examined for their electrical conductivity (σ) and magnetic susceptibility (χ_m) properties. A 291 cm core was obtained at Tegal Arum Village in South Kalimantan, Indonesia. The K-means clustering results indicate two different layers at 148 cm, and this is supported by loss on ignition (LOI) measurements. In the first layers, a 87.65% LOI was found associated with peat soils (above 248 cm). Whereas, in the second layers, there was a 26.11% LOI associated with mineral soils (below 248 cm). The results of this study using K-means clustering can be used to delineate soil layers.

The garnet Li₇La₃Zr₂O₁₂ (LLZO) has been widely investigated because of its high conductivity, wide electrochemical window and chemical stability to lithium metal. However, the usual preparation process of LLZO requires a long time of high-temperature sintering and a lot of mother powders against the lithium evaporation. The submicron Li₆.6La₃Zr₁.6Nb₀.4O₁₂ (LLZNO) powders are prepared by conventional solid-state reaction method and attrition milling process, which are stable cubic phase and have high sintering activity, and Li stoichiometric LLZNO ceramics are obtained by sintering at a relative lower temperature or for a short time by using these powders which are difficult to control under high sintering temperature and long sintering time. The particle size distribution, phase structure, microstructure, distribution of element, total ionic conductivity, relative density and activation energy of submicron LLZNO powders and LLZNO ceramics are tested and analyzed by laser diffraction particle size analyzer, XRD, SEM, EIS and Archimedean method. The total ionic conductivity of sample sintered at 1200 °C for 30 min is 5.09 × 10-4 S·cm-1, the activation energy is 0.311 eV, and the relative density is 87.3%, and sintered at 1150 °C for 60 min total ionic conductivity is 3.49 × 10-4 S·cm-1, the activation energy is 0.316 eV, and the relative density is 90.4%. At the same time, all-solid-state batteries are assembled with LiMn₂O₄ as positive electrode and submicron LLZNO powders as solid state electrolyte. After 50 cycles, the discharge specific capacity is 105.5 mAh/g and the columbic efficiency is above 95%.

Herein, we present preparation of solid polymer electrolyte (SPE) comprising of PEO, NaPF₆ and varying fraction of Succinonitrile (SN) by standard solution cast technique. The morphological features and structural properties were studied by the FESEM, XRD, respectively. FTIR was performed to study the interactions between polymer host, salt, and SN. Impedance spectroscopy, Transference number measurements, LSV and CV were used to examine the electrochemical properties. The complex permittivity/conductivity & modulus were studied to understand the dielectric properties by evaluating the dielectric strength, relaxation time, hopping frequency and dc conductivity. Based on the experimental results an interaction mechanism is presented.

The system of non-interacting electrically charged core-massless spring-shell mechanical units, demonstrating negative effective mass, is considered, seen as a Drude-Lorentz gas. When such an ideal gas is exposed to the external harmonic field, it demonstrates as the certain conditions the negative frequency-dependent electrical conductivity. The negative value of the electrical conductivity implies that the electrical current will flow against the direction of the electric field and correspondingly the direction of the electrical force. Low- and high-frequency asymptotic behavior of the electrical conductivity is addressed. The same system demonstrates at low frequencies the negative asymptotic refraction. Experimental realization of the introduced model system, based on the exploitation of plasma oscillations of the free electron gas is suggested.

Abstract Due to the relatively low efficiency of thermoelectric (TE) generators, they have mostly been used in niche applications where the unique properties of TE generators outweigh their lack of efficiency, or conditions where it is more reasonable to base the optimal design on maximum generated power rather than maximum efficiency. The aim of this work is to investigate how the different fundamental transport properties (Seebeck coefficient, thermal conductivity and electrical resistivity) in materials with equal figure of merit (ZT) impact TE module design and maximum power output. Further, we discuss and review the strategies to enhance material properties and the latest studies on the TE module performance. It is shown, that by increasing the power factor by a factor of 15 and decreasing the thermal conductivity by 13.33 in order to maintain ZT=1, power output is increased by 45%. This effect is stronger in lower module fill factor and thermal resistance of the heat source and heat sink.

Below T_CO=157 K the quasi-one-dimensional charge-transfer salt (TMTTF)_2SbF_6 undergoes a pronounced phase transition to a charge-ordered ground state. We have explored the non-linear and photoconductive behavior as a function of applied voltage, laser pulse energy and temperature. Besides a decay of the photoconductive signal in a double exponential fashion in the millisecond range, we discover current oscillations in the kHz range induced by the application of short laser pulses. While the resonance frequencies do not depend on voltage or laser intensity and vary only slightly with temperature, the amplitude changes linearly with the laser intensity and voltage. The findings are discussed and compared to comparable phenomena in other low-dimensional electron systems.

Nanostructured materials have already become an integral part of our daily life. In many applications ion mobility decisively affects the performance of, e.g., batteries and sensors. Nanocrystalline ceramics often exhibit enhanced transport properties due to their heterogeneous structure showing crystalline (defect-rich) grains and disordered interfacial regions. In particular, anion conductivity in nonstructural binary fluorides easily exceeds that of their coarse-grained counterparts. To further increase ion dynamics aliovalent substitution is a practical method to influence the number of (i) defect sites and (ii) the charge carrier density. Here, we used high energy-ball milling to incorporate Y³⁺ ions into the cubic structure of SrF₂. As compared to pure nanocrystalline SrF2 the ionic conductivity of Sr_1-xYxF_2+x with x = 0.3 increased by 4 orders of magnitude reaching 0.8 x 10 ^-5 S/cm^-1 at 450 K. We discuss the effect of YF₃ incorporation on conductivities isotherms determined by both activation energies and Arrhenius pre-factors. The enhancement seen is explained by size mismatch of the cations involved, which are forced to form a cubic crystal structure with extra F anions if x is kept smaller than 0.5

Bipolar plates significantly contribute in the development of the polymer electrolyte membrane (PEM) fuel cells technology due to their ability to produce high electrical conductivity based on type of materials used. Mismatching of inappropriate materials and manufacture may lead to the inferior performance of PEM fuel cells. Hence, material development was determined crucial to balance the overall performance of PEM fuels including the mechanical properties and electrical conductivity of the materials. Studies on conductive polymer composites (CPCs) offered filler orientation as an alternative method to enhance the overall performance of bipolar plate. Filler orientations permit an excellent conductivity network formation while controlling the filler alignment based on required applications. This paper reviewed various studies of filler orientations including materials used and methods of manufacture of CPC materials for the effective development of bipolar plate.

Had magnetic monopoles been ubiquitous as electrons do, we would have probably had a different form of matter, and power plants based on currents of these magnetic charges would have been a familiar scene of modern technology. Magnetic dipoles do exist however, and in principle one could wonder if we can use them to generate magnetic currents. In the present work, we discuss the issue of generating magnetic currents and magnetic thermal currents in electrically-insulating low-dimensional Heisenberg antiferromagnets by invoking the (broken) electricity-magnetism duality symmetry. The ground state of these materials is a spin-liquid state that can be described well via the Jordan-Wigner fermions, which permit an easy definition of the magnetic particle and thermal currents. The spin-liquid states in these antiferromagnets are either gapless or gapped liquids of spinless fermions whose flow defines a current just as the one defined for electrons in a Fermi liquid. The driving force for the magnetic current is a magnetic field with a gradient along the magnetic conductor. The present work is about claiming that what the experiments in spintronics attempt to do is trying to treat the magnetic degrees of freedoms on the same footing as the electronic ones.

Metal oxide based electrodes play a crucial role in various as a transparent conductive oxide (TCO). One of the metal oxides, nickel oxide is a promising electrical conductive material. Here, we display that incorporation of vanadium in NiO lattice significantly improve both electrical conductivity and hole extraction. Also, vanadium doped nickel oxide exhibits a lower crystalline size compared to pristine nickel oxide, which maintains the reduction of surface roughness. These results indicating that the vanadium is an excellent dopant for NiO.

The grain size of CVD (Chemical Vapor Deposition) graphene was controlled by changing the precursor gas flow rates, operation temperature, and chamber pressure. Graphene of average grain sizes of 4.1 µm, 2.2 µm, and 0.5 µm were synthesized in high quality and full coverage. The possibility to tailor the thermoelectric conversion characteristics of graphene has been exhibited by examining the grain size effect on the three elementary thermal and electrical properties of σ, S, and k. Electrical conductivity (σ) and Seebeck coefficients (S) were measured in a vacuum for supported graphene on SiO₂/Si FET (Field Effect Transistor) substrates so that the charge carrier density could be changed by applying a gate voltage (V_G). Mobility (µ) values of 529~1042, 459~745, and 314~490 cm²/V·s for the three grain sizes of 4.1 µm, 2.2 µm, and 0.5 µm, respectively, were obtained from the slopes of the measured σ vs. V_G graphs. The power factor (PF), the electrical portion of the thermoelectric figure of merit (ZT), decreased by about one half as the grain size was decreased, while the thermal conductivity (k) decreased by one quarter for the same grain decrease. Finally, the resulting ZT increased more than two times when the grain size was reduced from 4.1 µm to 0.5 µm.

Thermal interface material (TIM) that can exist as liquid at the service temperature enables efficient heat transfer across two adjacent surfaces in electronic applications. In this work, the thermal conductivities of different phase regions in the Ga-In system at various compositions and temperatures are measured for the first time. A modified comparative cut bar technique is used for the measurement of the thermal conductivities of In_xGa_1-x (x=0, 0.1, 0.214, 0.3, and 0.9) alloys at 40, 60, 80, and 100^oC that are the temperatures commonly encountered in consumer electronics. The thermal conductivity values for the liquid and semi-liquid (liquid+β) Ga-In alloys are higher than the TIM currently used in consumer electronics. These measured quantities, along with the available experimental data from the literature, served as input for the thermal conductivity parameter optimization using the CALPHAD (CALculation of PHase Diagram) method for the pure elements, solution phase, and two-phase region. A set of self-consistent parameters for the description of the thermal conductivity of the Ga-In system is obtained. There is good agreement between the measured and calculated thermal conductivity values for all the phases. Hence, it can be envisaged that liquid/semi-liquid Ga-In alloys can be considered as a potential TIM in consumer electronics due to its high thermal conductivity.

The optical conductivity in the charge order phase is calculated in the extended Hubbard model describing an organic Dirac electron system α-(BEDT-TTF)₂I₃ using the mean field theory and the Nakano-Kubo formula. A peak structure due to interband excitation being characteristic in two-dimensional Dirac electron system is found above the charge order gap. It is shown that the peak structure originates from the Van Hove singularities of the conduction and valence bands, where those singularities are located at a saddle point between two Dirac cones in momentum space. The frequency of the peak structure exhibits drastic change in the vicinity of the charge order transition.

In the present work freezing and melting characteristics of water seeded with chemically functionalized graphene nano-platelets in a vertical cylindrical capsule was experimentally studied. The volume percentage of functionalized graphene nano-platelets was varied from 0.1% to 0.5% with an interval of 0.1%. The stability of the synthesised samples were carried out by zeta potential distribution. The thermal conductivity of the nanocomposite samples were experimentally measured using transient hot wire method. A maximum enhancement of ~24% in the thermal conductivity was observed for the 0.5% volume percentage in the liquid state while a ~53% enhancement in the solid state. Freezing and melting behaviour of water dispersed with graphene nanoplatelets were carried out using a cylindrical stainless steel capsule in a constant temperature bath. The bath temperatures considered for studying freezing characteristics were considered to be −6 °C and −10 °C, while to study the melting characteristics the bath temperature was set as 31 °C and 36 °C. The freezing and melting time decreased for all the test conditions when the volume percentage of GnP increased. The freezing rate was enhanced by ~ 43% and ~32% for the bath temperatures of −6 °C and −10 °C respectively at 0.5 vol % of graphene loading. The melting rate was enhanced by ~42% and ~63% for the bath temperature of 31 °C and 36 °C respectively at 0.5 vol % of graphene loading.

This is the second of a two-paper series describing a multi-scale modeling approach developed to simulate crack sensing in polymer fibrous composites by exploiting interruption of electrically conductive carbon nanotube (CNT) networks. The approach is based on the finite element (FE) method. FE models at three different scales, namely the micro-scale, the meso-scale and the macro-scale, have been developed using the ANSYS PDL environment. In the present paper, the meso- and macro-scale analyses are described. In the meso-scale, a two-dimensional model of the CNT/polymer matrix reinforced by carbon fibers is used to develop a crack sensing methodology from a parametric study which relates the crack position and length with the reduction of current flow. In the meso-model, the effective electrical conductivity of the CNT/polymer computed from the micro-scale is used as input. In the macro-scale, the final implementation of the crack sensing methodology is performed on a CNT/polymer/carbon fiber composite volume using as input the electrical response of the cracked CNT/polymer derived at the micro-scale and the crack sensing methodology. Analyses have been performed for cracks of two different lengths. In both cases, the numerical model predicts with good accuracy both the length and position of the crack. These results highlight the prospect of conductive CNT networks to be used as a localized structural health monitoring technique.

Polymer composites with high thermal conductivity have a great potential for applications in modern electronics due to their low cost, easy process, and stable physical and chemical properties. Nevertheless, most polymer composites commonly possess unsatisfactory thermal conductivity, primarily because of the high interfacial thermal resistance between inorganic fillers. Herein, we developed a novel method through silver functionalized graphene nanosheets (GNS) and multiwalled carbon nanotube (MWCNT) composites with excellent thermal properties to meet the requirements of thermal management. The effects of composites on interfacial structure and properties of the composites were identified, and the microstructures and properties of the composites were studied as a function of the volume fraction of fillers. An ultrahigh thermal conductivity of 12.3 W/mK for polymer matrix composites was obtained, which is an approximate enhancement of 69.1 times compared to the polyvinyl alcohol (PVA) matrix. Moreover, these composites showed more competitive thermal conductivities compared to untreated fillers/PVA composites applied to the desktop central processing unit, making these composites a high-performance alternative to be used for thermal management.

Over the years, leaked fluids from the aircraft caused severe deterioration of the airfield pavement. The combined effect of hot exhaust from the auxiliary power unit of military aircraft and spilt aviation oils caused rapid pavement spalling. If the disintegrated concreted pieces caused by spalling is sucked into the jet engine, it may cause catastrophic damage to the aircraft engine or physical injury to maintenance crews. This study investigates the effectiveness of incorporating hybrid fibres into ordinary concrete to improve the residual mechanical and thermal properties to prevent spalling damage of pavement. Three fibre reinforced concrete samples made with micro steel fibre and polyvinyl alcohol fibre with a fibre content of zero, 0.3%, 0.5% and 0.7% by volume fraction. These samples were exposed to recurring high temperature and aviation oils. Tests were conducted to measure the effects of repeated exposure on the concrete's mechanical, thermal and chemical characteristics. The results showed that polyvinyl alcohol fibre reinforced concrete suffered a significant loss of thermal properties and residual mechanical strength than the micro steel fibre reinforced concrete. However, hybrid fibre reinforced concrete performed better in retaining higher residual properties, and no spalling of concrete was observed.

Recently published structural analysis and galvanomagnetic studies of a large number of different bulk and mesoscopic graphite samples of high quality and purity reveal that the common picture assuming graphite samples as a semimetal with a homogeneous carrier density of conduction electrons is misleading. These new studies indicate that the main electrical conduction path occurs within 2D interfaces embedded in semiconducting Bernal and/or rhombohedral stacking regions. This new knowledge incites us to revise experimentally and theoretically the diamagnetism of graphite samples. We found that the $c$-axis susceptibility of highly pure oriented graphite samples is not really constant but can vary several tens of percent for bulk samples with thickness $t \gtrsim 30~\mu$m, whereas by a much larger factor for samples with smaller thickness. The observed decrease of the susceptibility with sample thickness resembles qualitatively the one reported for the electrical conductivity and indicates that the main part of the $c-$axis diamagnetic signal is not intrinsic of the ideal graphite structure but it is due to the highly conducting 2D interfaces. The interpretation of the main diamagnetic signal of graphite agrees with the reported description of its galvanomagnetic properties and provides a hint to understand some magnetic peculiarities of thin graphite samples.

In recent years, it has been found in engineering practice that the service life of cemented carbide shield machine tools used in uneven soft and hard strata is substantially reduced. The study found that thermal stress is the main reason for the failure of cemented carbide shield tunneling tools when shield tunneling is carried out in uneven soft and hard soil. To maintain the hardness of cemented carbide, improving the thermal conductivity of the shield machine tool is of great importance for prolonging its service life and reducing engineering costs. In this paper, graphene and carbon nanotubes were mixed with WC-Co powder and sintered by SPS (Spark Plasma Sintering). The morphology was observed by using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). A Rockwell hardness tester and bending strength tester were used to test hardness, bending strength and thermal conductivity. The results show that adding trace graphene or carbon nanotubes can increase the bending strength of the cemented carbide by approximately 50% while keeping the hardness of the cemented carbide unchanged. The thermal conductivity of the cemented carbide can be increased by 10% with the addition of 0.12% graphene alone.

In our recent works we reported that physical and chemical characteristics of serum can vary in relation to the psychic activity of an individual depending on whether it is oriented to stress or relaxation. We wandered if these observations could be accompanied by an appreciable modification of the Ph, electric conductivity and Delayed Luminescence of the same serum samples. Our preliminary data may suggest that the serum pH could significantly increase during a Relaxation Response intervention while electric conductivity seems to decrease. Moreover, Delayed Luminescense could vary in the same subject according to the Relaxation Response practice. According to our proof of concept study, we postulate the appearance of a coherent system within the blood samples analyzed after the Relaxation Response. Further researches and some technical development are needed to support our preliminary findings.

This study investigated the evolution of density, gas permeability and thermal conductivity of sugar maple wood during the thermo-hygro-mechanical densification process. The results suggested that the oven-dry average density of densified samples was significantly higher than that of the control samples. However, the oven-dry density did not show a linear increase with the decrease of wood samples thickness. The radial intrinsic gas permeability of the control samples was 5 to 40 times higher than that of densified samples, which indicated that the void volume of wood was reduced notably after the densification process. The thermal conductivity increased by 0.5 - 1.5% per percent increase of moisture content for densified samples. The thermal conductivity of densified wood was lower than that of the control samples. The densification time had significant effects on the oven-dry density and gas permeability. Both the densification time and the moisture content had significant effects on thermal conductivity, but their interaction effect was not significant.

In this paper, an icosahedral non – body centered model to simulate the periodic structure of homogeneous particulate composites, by predicting the particle arrangement, is presented. This model has yielded three different variations which correspond at three different deterministic particle configurations. In addition, the concept of boundary interphase between matrix and inclusions was taken into account. Thus, the influence of particle vicinity was examined in parallel with the interphase concept on the thermomechanical properties of the overall material. Next, by the use of this model the authors derived a closed – form expression to estimate the thermal conductivity of this type of composites. To test the validity of the model, the theoretical values arising from the proposed formula were compared with other theoretical predictions obtained from several accurate formulae found in the literature and an adequate accordance was observed.

The objective of this study was to investigate successional changes in water flow as a result of changes in soil hydraulic properties after crop abandonment under drought and non-drought conditions, and under water uptake by co-occurring perennial plant species to clarify the observation that typical perennial grass species are seldom observed in abandoned fields. Soil hydraulic properties were measured in croplands which had been abandoned for different periods (2, 9, and 18 years from abandonment) and in a grazed grassland site. Hydrological processes in the soil profiles were simulated with soil hydraulic properties under drought and non-drought summer conditions with water uptake from perennial grass species Suction in the surface soils increased with the period of abandonment, with this trend being particularly obvious in a drought year. Available water appears to be restricted in the later successional stage of abandoned fields and in grazed grassland for plants that have drought tolerance. Dry soil and climate conditions are important factors determining the intrusion of the typical perennial grass, S. krylovii, into degraded abandoned fields. This abiotic interaction between soil hydraulic properties and climate conditions may play an important role for plant succession in abandoned cropland.

Previously, a conductivity invariance phenomena (CIP) has been discovered – at a certain lift-off, the inductance change of the sensor due to a test sample is immune to conductivity variations, i.e. the inductance – lift-off curve passes through a common point at a certain lift-off, termed as conductivity invariance lift-off. However, this conductivity invariance lift-off is fixed for a particular sensor setup, which is not convenient for various sample conditions. In this paper, we propose using two parameters in the coil design – the horizontal and vertical distances between the transmitter and the receiver to control the conductivity invariance lift-off. The relationship between these two parameters and the conductivity invariance lift-off is investigated by simulation and experiments and it has been found that there is an approximate linear relationship between these two parameters and the conductivity invariance lift-off. This is useful for applications where the measurements have restrictions on lift-off, e.g. uneven coating thickness which limits the range of the lift-off of probe during the measurements. Therefore, based on this relationship, it can be easier to adjust the configuration of the probe for a better inspection of the test samples.

Accumulative roll bonding (ARB) is one of methods of severe plastic deformation which is relevant for industrial production of sheets. While mechanical properties of several magnesium alloys subjected to ARB process have been studied, the physical properties have been reported only for some magnesium alloys. These properties are influenced by the texture developed during the ARB process and the temperature load. In the presented contribution, we studied thermal diffusivity and thermal conductivity of an AZ31 magnesium alloy after 1 and 2 passes through the rolling mill. Thermal diffusivity was measured with the laser-flash method in the temperature range between 20 and 350 °C. Thermal conductivity depends on the number of rolling passes. The microstructure and texture of sheets are significant factors influencing the thermal properties.

This paper has experimentally measured volcanic tufa electrical conductance. The calculations are carried out in accordance with the potential of cyclic voltammetry in a constant state. The cyclic voltammograms nanoelectrode platinum prepared electrochemically were examined in the range -0.2 to 1.2 V vs. AgCl [Cl^-]:1.0 M in the presence and absence of volcanic tuff in the aqueous solution of 1.0 M HCl. The cyclic voltammetry studies show that the Nano platinum film suffers degradation when the potential exceeds +0.85 V, and below this potential, it is quite stable. The redox reaction of the electrode is reversible. The nanoparticle platinum synthesized at low temperature and high acid concentration exhibits higher electronic conductivities. It has been observed that, relative to area under the peak aggregate tests, the use of volcanic concrete was showing a large increase in electrical conductivity. It was shown that with cyclic voltammetry, three well-defined anode peak could be achieved at a power of 0.0, 0.4 and 0.6 V versus Ag/AgCl.

The contact materials in high-voltage vacuum interrupter require properties such as high conductivity, high density, and high hardness to minimize arc heat damage. In this study, copper–molybdenum-chromium alloys contact materials are examined for a high voltage contact material. Ball milling process was carried out after analyzing the raw materials of copper, chromium, and molybdenum powders. A green compact was produced using a high press with the mixed powder. Afterwards, composite was produced by sintering method according to temperature and infiltration method according to Cu content in green compact. The composite of sintering method showed a density of 8.55 g/cm3 (relative density 93%) a hardness of 217 HV, and an electrical conductivity of 40.7 IACS% at 1200 °C. The composite of 10 wt.% Cu produced by the Cu infiltration method showed a density of 8.7 g/cm3 (relative density 94%), Hardness of 274HV and electrical conductivity of 39 IACS% at 1300 °C. The measurements of physical properties showed the new possibility of using the Cu–Cr–Mo alloy as a contact material for high-voltage vacuum interrupters.

The electrical, mechanical and thermal conductivity of ethylene butene copolymer (EBC) composites with carbon fibers were studied. EBC/carbon-fiber composites can be utilized as an electro-mechanical material which is capable of changing it electric resistance with mechanical strain. Carbon fibers were introduced to EBC with different concentrations (5-25 wt%). The results showed that the addition of carbon fibers to EBC could increase the electric resistance up to 10 times. Increasing the load to 2.9 MPa could increase the electric resistance change by 4500% compared 25% fiber sample with pure EBC. It is also noted that the electric resistance of the EBC/CF composites underwent a dramatic increase with raising the strain, for example, the resistance change was around 13 times more at 15% strain in comparison to 5% of strain; The thermal conductivity tests showed that the addition of carbon fibers could increase the thermal conductivity by 40%, from 0.19 to 0.27 (Wm-1K-1). It was also observed that the addition of carbon fibers to EBC could increase the thermal conductivity.

Soil hydraulic properties are often derived indirectly, i.e. computed from easily available soil properties with pedotransfer functions (PTFs), when those are needed for catchment, regional or continental scale applications. When predicted soil hydraulic parameters are used for the modelling of the state and flux of water in soils, uncertainty of the computed values can provide more detailed information when drawing conclusions. The aim of this study was to update the previously published European PTFs (Tóth et al., 2015, euptf v1.4.0) by providing prediction uncertainty calculation built into the transfer functions. The new set of algorithms was derived for point predictions of soil water content at saturation (0 cm matric potential head), field capacity (both -100 and -330 cm matric potential head), wilting point (-15.000 cm matric potential head), plant available water, and saturated hydraulic conductivity, as well as the Mualem-van Genuchten model parameters of the moisture retention and hydraulic conductivity curve. The minimum set of input properties for the prediction is soil depth and sand, silt and clay content. The effect of including additional information like soil organic carbon content, bulk density, calcium carbonate content, pH and cation exchange capacity were extensively analysed. The PTFs were derived adopting the random forest method. The advantage of the new PTFs is that they i) provide information about prediction uncertainty, ii) are significantly more accurate than the euptfv1, iii) can be applied for more predictor variable combinations than the euptfv1, 32 instead of 5, and iv) are now also derived for the prediction of water content at -100 cm matric potential head and plant available water content.

One of the intriguing recent results in the field of high-entropy alloys is the discovery of single-phase equiatomic multi-component Laves intermetallics. However, there is no clear understanding that a combination of chemical elements will form such high-entropy compounds. Here we contribute to understanding this issue by modifying the composition of duodenary TiZrHfNbVCrMoMnFeCoNiAl (12x) alloy in which we recently reported the fabrication of hexagonal C14 Laves phase. We consider three alloys based on 12x: 7x=12x-VCrMoMnFe, 12x+Sc, 12x+Be and observe that all of them crystalize with the formation of C14 Laves phase as a dominant structure. We report that 12x+Be alloy reveals single-phase C14 structure with very high concentration of structural defects and ultra-fine dendritic microstructure with almost homogenous distribution of the constituted elements over the alloy matrix. The 7x and 12x+Sc alloys contain C14 as a main phase and unknown impurity phases. To characterize the materials, we examine their heat capacity, electrical conductivity and magnetic properties. The measurements reveal that the Laves phases are Curie-Weiss paramagnets, which demonstrate metallic conduction; 7x and 12x alloys also reveal a pronounced Kondo-like anomaly. Analysis of experimental data as well as ab initio calculations suggests that chemical complexity and compositional disorder cause strong s-d band scattering and thus the rather high density of d-states in the conduction band. Analysis of the results suggests that the mechanism of Laves phase formation in multicomponent multi-principal element metallic alloys is may be the same as in polydisperse hardspheres mixtures. Another important conclusion is that the configurational entropy is a negligible factor in the stabilization of multi-element Laves phases.

Hydraulic conductivity is the key and one of the most uncertain parameters in groundwater modeling. The grid based numerical simulation require spatial distribution of sampled hydraulic conductivity at un-sampled locations in the study area. This spatial interpolation has been routinely performed using variogram based models (two-point geostatistics methods). These traditional techniques fail to capture the complex geological structures, provides smoothing effects and ignore the higher order moments of subsurface heterogeneities. In this work, a multiple-point geostatistics (MPS) method is applied to interpolate hydraulic conductivity data which will be further used in WASH123D numerical groundwater simulation model for regional smart groundwater management. To do this, MPS need ‘training images (TIs) as a key input. TI is a conceptual model of subsurface geological heterogeneity which was developed by using concept of ages, topographic slope as an index criteria and knowledge of geologist. After considerations of full physics of study area, an example shows the advantages of using multiple-point geostatistics compared with the traditional two-point geostatistics methods (such as Kriging) for the interpolation of hydraulic conductivity data in a complex geological formation.

In the presented paper, a comprehensive study will be done on shape factor analysis of MoS2-GO in H2O-C2H6O2 based hybrid nanoliquids associated with effect and influence of transverse magnetic field and thermal radiation. The effect of variation in different parameters and nanoliquids shapes under temperature and velocity distribution is explored and also non-linear thermal radiation will be analyzed. Algorithms are introduced in proportion to mathematical modeling based on their numerical results and comparative curves for further explanation. In addition, it will be done research for influence and effect of new significant parameters emerged to the model to do sensitivity analysis and also their output results are demonstrated, examined and compared together by presenting graphs and tables. Based on detailed discussions, authentication of attained results designates the high accuracy of applied methods deployed to solve presented model in the paper. Our results satisfy that our used approach is accurate, highly reliable and also effective. All mentioned steps will be described throughout the literature.

In this work, PMMA(Poly methyl methacrylate) microfluidic system was used as a micro-reactor for urea hydrolysis by urease enzyme with use conductivity principle and utilize sound level meter(SLM) App in smartphone as a novel detector by considering the peak height in the App as an indicate for urea concentration. the advantage of use small volume and how the reaction carried on in the microfluidic system with simple and low cost are discussed, and the results were analyzed and statically determine. The linearity, detection limit (3×noise )and Correlation Coefficient, 62.5-500 ppm, 31.25 ppm and 0.992 respectively also, recovery studied were between(98.5-100.13%).

The phase composition design principle is introduced to obtain balanced properties of ionic conductivity and thermo-tolerant for zirconia solid electrolytes used in solid oxide fuel cells (SOFCs). The zirconia ceramic solid electrolytes are fabricated by two-step free sintering. With increasing Y/Mg ionic ratio from 1.78:1 to 1.88:1, the content of monoclinic phase fluctuates little (±3%). The ionic conductivity, including the total electrical resistance; grain electrical resistance and grain boundary electrical resistance at 1223K, are all gradually declining with the increasing of Y/Mg ionic ratio. Furthermore, the enrichment of Mg ion in grain boundary acts as a disincentive to grain boundary ionic conductivity. In addition, the maximum total equivalent conductivity at 1223K in this study reaches to 0.143 Scm-1 which can compare with that of certain YSZ. It will be beneficial to SOFCs application profited from increasing ionic conductivity of ceramic solid electrolytes.

The molecular dynamics simulation has been used to investigate the structural and transport properties of (Ba_0.5-xSr_x)La_0.5InO_3-δ (x=0, 0.1, 0.2) oxygen-ion conductor. The previous studies reported that the ionic conductivity of Ba-doped LaInO3 decreases because Ba dopant forms narrow oxygen path in the lattice, which could hinder the diffusion of oxygen ion. In this study, we reveal the mechanism to improve the ionic conductivity by Ba and Sr co-doping on La site in LaInO3 perovskite oxide. The results show that the ionic conductivity of (Ba_0.5-xSr_x)La_0.5InO_3-δ increases with increasing numbers of Sr ions, which oxygen diffusion paths including Sr ion have larger critical radius than Ba ions. The RDF calculations showed the heights of peak in composition including Sr ions is lower and broaden, so oxygen ions moved easily into other oxygen sites.

To date, zinc ion batteries (ZIBs) have been attracting extensive attention due to their outstanding properties and the potential to be the solution for next-generation energy storage systems. However, the uncontrollable growth of zinc dendrites and water-splitting issues seriously restrict the further scalable application. Over the past few years, solid polymer electrolytes (SPEs) have been regarded as a promising alternative to address these challenges and facilitate the practical advancement of zinc batteries. In this review, we revisited the research progress of SPEs applied in zinc batteries in the past few years and focus on introducing cutting-edge polymer science and technologies that can be utilized to prepare advanced SPEs for high-performance zinc batteries. The operating mechanism of SPEs and the functions of polymers will be summarized. To highlight the polymer functions, SPEs are categorized into three types, respectively, homogenous polymer SPEs, hybrids polymer SPEs, and nanocomposites SPEs, which are expected to reveal the roles and principles of various polymers in zinc batteries. This review presents the current research progress and fundamental mechanisms of polymer-based SPEs in zinc batteries, outlines the challenging issues encountered, and meanwhile proposes potential solutions for future endeavours.

A novel hybrid material based on Polyvinyl alcohol-Chitosan (PVA-Cs) was made, reinforced with conductive polymer fillers such as polypyrrole (PPy), Poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS), carbon black (CB) and multi-wall carbon nanotubes (MW CNT). Our proposal is to use these fillers, which have not been studied in this context before, for obtaining composite materials, and to characterize them for the development of applications in microelectronics. FTIR analysis made evident the different func-tional groups present in the matrix and the fillers used. The use of quaternary mixtures (4 fillers) increased the contact angle, which increased the degree of hydrophobicity of the biocomposite. The Nyquist diagram of the analyzed samples showed a decrease in resistance and energy diffu-sion; the latter due to the transfer of electrons caused by the conductive polymers CB and the MWCNT. In the mechanical tension tests, Young's modulus values of 18.386 MPa were obtained, in contrast with the material matrix of PVA-Cs, which showed values of 11.628 MPa. Further-more, morphological analysis by SEM showed that the materials obtained were homogeneous, with no phase formation. The materials obtained showed higher electrical conductivity in the presence of the OH and NH2 groups, which could have possible applications in biopolymer elec-trodes.

Soil water loss by evaporation influences the sodium adsorption ratio (SAR) of irrigation drainage water. Evaporation concentrates sodium and magnesium but calcite precipitation has a more complicated effect on soluble calcium and alkalinity. Here we propose a revised sodicity hazard assessment that quantifies the impact of evaporative water loss and calcite precipitation on drainage water SAR. This paper shows sodicity hazard is determined by the initial composition of irrigation water as originally suggested by previous researchers, and provide a simple, accurate way to identify the potential sodicity hazard of any irrigation water. In particular, the initial equivalent concentration of alkalinity and calcium determine the salinization pathway followed during evaporation. If the irrigation water alkalinity exceeds soluble calcium expressed as equivalent concentrations, drainage water SAR approaches an upper limit determined by the initial relative concentration of sodium and magnesium. If irrigation water alkalinity is less than soluble calcium, drainage water SAR approaches a lower limit determined by the initial calcium, magnesium and sodium. In both cases the SAR is scaled by the square root of the concentration factor √Fc quantifying soil water loss. To assess the impact of evaporation and calcite precipitation on the SAR and test the accuracy of the new sodicity hazard assessment, we evaluated data from previously published lysimeter studies. We plotted water composition boundaries for each source water, comparing these boundaries to the drainage water composition recorded in the lysimeter studies. As salinity increased by evaporation, each drainage water followed a distinct salinization path.

The simultaneous evaluation of heat/mass transference procures momentous significance in the polymer industry and engineering activities. Extensive utilization of such aspects includes propylene flares, heat exchangers, energy transfiguration in chilling towers, and amputation of post fortuitous heat in nuclear reactors. Owing to such prospective demands, we interpreted the Jeffrey liquid reactive flow under non-linear convection. We scrutinized the transference of heat/mass under generalized Fourier-Fick relations. Thermal conductivity depends on temperature while mass diffusivity is dependent on concentration. Besides, heat source along with first-order chemical reaction aspects are accounted for. Relevant transformations are exerted to achieve non-linear differential systems that are solved through the homotopy scheme. Influences of divers factors are exhibited via graphical benchmark.

High temperature (HT) significantly affects the crop physiological traits and reduces the 12 productivity in plants. To increase yields as well as survival of crops under HT, developing heat13 tolerant plants is one of the main targets in crop breeding programs. The present study attempted 14 to investigate the linkage of the heat tolerance between the seedling and the reproductive growth 15 stages of tomato cultivars ’Dafnis‘ and ’Minichal’. This research was undertaken to evaluate heat 16 tolerance under two experimental designs such as screening at seedling stage and screening from 17 reproductive traits in greenhouses. Survival rate and physiological responses in seedlings of 18 tomatoes with 4-5 true leaf were estimated under HT (40 °C, RH 70%, day/night, respectively) and 19 under two control and HT greenhouse conditions (day time 28 °C and 40 °C, respectively). Heat 20 stress significantly affected physiological-chemical (photosynthesis, electrolyte conductivity, 21 proline) and vegetative parameters (plant height, shoot fresh weight, root fresh weight) in all 22 tomatoes seedlings. The finding revealed that regardless of tomato cultivars the photosynthesis, 23 chlorophyll, total proline and electrical conductivity parameters were varied in seedlings during the 24 heat stress period. The heat tolerance rate of tomatoes in the seedling stage might not be associated 25 always with reproductive parameters. HT reduced the fruit parameters likeas fruit weight (31.9%), 26 fruit length (14.1%), fruit diameter (19.1%) and fruit hardness (9.1%) in compared to NT under HT 27 in heat susceptible tomato cultivar ‘Dafnis’, while in heat tolerant cultivar ‘Minichal’ fruit length 28 (7.1%) and fruit diameter (12.1%) was decreased by the affect of HT but on the contrary fruit weight 29 (3.6%) and fruit hardness (8.3%) were increased. In conclusion, screening and selection for tomatoes 30 should be evaluated at the vegetative and reproductive stages with consideration of reproductive 31 parameters.

Density Functional Theory (DFT) full potential linearized augmented plane wave (FP-LAPW) method with the Modified Becke-Johnson (mBJ) approximation is used to perform spin polarised calculations of the transition metal perovskites MoScO₃ and WScO₃. Both depict half metallic behaviour with semiconducting and metallic in the minority and majority spins respectively. MoScO₃ and WScO₃ have indirect R− Γ band gaps in the minority spin channels of 3.61 and 3.82eV respectively. Moreover, they both show substantial magnetic moments of 2.99μ_B. In addition, we calculate the dielectric function, optical conductivity and the optical constants, namely, the refractive index, the reflectivity, the extinction and absorption coefficients.

Herein, we report on a giant thermoelectric figure of merit of a non-degenerate fluorine-doped single-walled carbon nanotube (FSWCNT) using a tractable analytical approach and the phonon lattice Boltzmann model (LBM). We investigate the influence of the doping concentration, and the overlapping integrals on the ZT. The ZT and the temperature range of operation can be tuned using the doping (impurity) concentration and the overlapping integrals, respectively. The lattice thermal conductivity obtained using the phonon LBM was calculated to be 107.2 W/mK which yielded a ZT greater than 20. Interestingly, the ZT obtained is higher than what has been reported in superlattices, (ZT~1.4) and superlattice nanowire, (ZT~ 4) at 300 K, making FSWCNT a potential candidate for thermoelectric applications.

The optoelectronic properties of free standing monolayer (ML) hexagonal boron nitride (h-BN) is investigated for potential solar energy conversion applications using the Density Functional Theory (DFT) full potential linearized augmented plane wave (FP-LAPW) method. In addition, the bulk optical properties have also been calculated for the sake of comparison. The dielectric functions, optical conductivities and the optical constants are evaluated using the relaxed structures from electronic total energy pseudopotential calculations. The results reinforce previous research on h-BN DUV optoelectronics and demonstrate the suitability of its use as a component in deep ultraviolet (DUV) and energy conversion devices.

Understanding the mechanism for heat tolerance is important for the hot pepper breeding program to develop heat-tolerant cultivars in changing climate. This study was conducted to investigate physiological and biochemical parameters related to heat tolerance and to determine leaf heat damage levels critical for selecting heat-tolerant genotypes. Seedlings of two commercial cultivars, heat-tolerant ‘NW Bigarim’ (NB) and susceptible ‘Chyung Yang’ (CY), were grown in 42 °C for ten days. Photosynthesis, electrolyte conductivity, proline content were measured among seedlings during heat treatment. Photosynthetic rate was significantly reduced in ‘CY’ but not in ‘NB’ seedlings in 42 °C. Stomatal conductivity and transpiration rate was significantly higher in ‘NB’ than ‘CY’. Proline content was also significantly higher in ‘NB’. After heat treatment, leaf heat damages were determined as 0, 25, 50 and 75% and plants with different leaf heat damages were moved to a glasshouse (30–32/22–24 °C in day/night). The growth and developmental parameters were investigated until 70 days. ‘NB’ was significantly affected by leaf heat damages only in fruit yield while ‘CY’ was in fruit set, number and yield. ‘NB’ showed fast recovery after heat stress compared to ‘CY’. These results suggest that constant photosynthetic rate via increased transpiration rate as well as high proline content in heat stress condition confer faster recovery from heat damage of heat-tolerant cultivars in seedlings stages.

Steam boiler has a significant role in the industrial sector. The failure in boiler tubes significantly reduces the availability of the plant. Furthermore, deposits on the inner tube wall contribute to such failure by changing the thermal resistance of the wall, which causes a significant increase in the tube wall's temperature and, consequently, lower allowable stress. The presented thermal-fluid model is developed for the water tube. The model is implemented using ANSYS FLUENT to estimate the wall maximum water tube wall temperature considering the deposits layer and then determine the minimum thickness of the tube wall via ASME standards to assure safe operation. The model is verified via a mesh independence test. The minimum tube thickness is recommended and justified given the thermo-mechanical performance of the water tubes at several operating loads of 50, 75, and 100 %. These loads are implemented by different convective heat transfer coefficients of flue gases under different deposit thicknesses, thermal conductivity, and flue gas temperature. The present work contributes to the literature by recommending the minimum thickness of the water wall tubes and highlighting the thermo-mechanical effect of the deposits on water tube resilience under different operating conditions.

The electrokinetics methods have a great potential to characterize hydrogeological processes in geological media, especially in complex hydrosystems such as fractured formations. In this work, we conceptualize fractured media as a bunch of parallel capillary fractures following the fractal size distribution. This conceptualization permits to obtain analytical models for both the electrical conductivity and the electrokinetic coupling in water saturated fractured media. We explore two different approaches to express the electrokinetic coupling. First, we express the streaming potential coupling coefficient as a function of the zeta potential and then we obtain the effective charge density in terms of macroscopic hydraulic and electrokinetic parameters of porous media. We show that when the surface electrical conductivity is negligible, the proposed models reduces to the previously proposed one based on a bundle of cylindrical capillaries. This model opens up a wide range of applications to monitor the water flow in fractured media.

Low night temperature (LNT) can be a practical and economical target in tomato breeding programs in terms of energy saving in greenhouses. This study was conducted to investigate the physiological responses to LNT using four tomato accessions of cherry and large fruit types with LNT tolerance and sensitivity grown in two greenhouses with night temperature set-points of 10 and 15°C for heating. LNT significantly reduced plant height regardless of fruit types and LNT tolerance. The number of flowers were significantly reduced in 10°C in cherry but not in large fruit types. Fruit set in 10°C was significantly lower in LNT sensitive accessions than tolerant ones regardless of fruit types, which was due to abnormal flower morphology in 10°C. Proline accumulation patterns between 10 and 15°C significantly differed between fruit types as well as between LNT tolerant and sensitive accessions. Chlorophyll content in 10 °C was significantly higher at later growth stages in LNT tolerant accessions than sensitive ones in both fruit types. No clear difference in photosynthetic parameters was observed between fruit types or tolerance and sensitive accessions except for photosynthetic rate, which was significantly lower in tolerant than sensitive accessions during early growing period. These results suggest that different tomato fruit types may have different mechanisms for LNT tolerance.

Crystallization is a significant procedure in the manufacturing of many pharmaceutical and solid food products. In-situ Electrical Resistance Tomography (ERT) is a novel Process Analytical Tool (PAT) to provide a cheap and quick way to test, visualize, and evaluate the progress of crystallization processes. In this work, the spatial accuracy of the non-conductive phantoms in low conductivity solutions was evaluated. Gauss-Newton, Linear Back Projection, and iterative Total Variation reconstruction algorithms were used to compare the phantom reconstructions for tap water, industrial-grade saturated sucrose solution, and demineralized water. Cylindrical phantom measuring 10 mm in diameter and a cross-section area of 1.5 % of the total beaker area was detected at the center of the beaker. Two phantoms with a 10 mm diameter were visualized separately in non-central locations. The quantitative evaluations were done for the phantoms with radii ranging from 10 mm to 50 mm in demineralized water. Multiple factors such as ERT device and sensor development, FEM mesh density and simulations, image reconstruction algorithms, number of iterations, segmentation methods, and morphological image processing methods were discussed and analyzed to achieve spatial accuracy. The development of ERT imaging modality for the purpose of monitoring crystallization in low conductivity solutions was performed satisfactorily.

The manuscript reported the synthesis of Al2O3 nano-coating onto quartz fiber by plasma electrolysis spray for enhanced thermal conductivity and stability. The nano- and micro-sized clusters were partially observed on the coating, while most coating was relatively smooth. It was suggested that the formation of a ceramic coating was followed as the nucleation-growth raw, that is, the formation of the coating clusters was dependent on the fast grow-up partially, implying the inhomogeneous energy distribution in the electrolysis plasma. The deposition of the Al2O3 coating increased the annealing tensile strength from 19.2 MPa to 58.1 MPa. The thermal conductivity of the coated quartz fiber was measured to be 1.17 W m-1 K-1, increased by ~45% compared to the bare fiber. The formation mechanism of the Al2O3 coating was preliminarily discussed. We believe that the thermally conductive quartz fiber with high thermal stability by plasma electrolysis spray will find a wide range of applications in industries.

Abstract— In this paper, degradation effects such as the self-heating effect and the DIBL effect in 2D-MoS2-based MOSFETs are investigated through simulations. These are transistors with Al2O3 and HfO2 as the gate oxide and SiO2 and HfO2 as the back oxide (BOX). The self-heating effect (SHE) is simulated using the thermodynamic transport model. The dependence of the DIBL effect (Drain Induced Barrier Lowering) and the lattice temperature in the center of the channel on the gate length for transistors with different gate oxide and BOX materials is considered. Transistors are considered where the channel is fully and partially (just below the gate) covered by gate oxide. It is shown that the transistors with Al2O3 as gate oxide and SiO2 as BOX materials have higher immunity to DIBL effect and transistors with HfO2 as gate oxide and HfO2 as BOX materials have higher immunity to SHE.

The internet of things and growing demand for smaller and advanced devices has created the problem of high heat production in the electronic equipment which greatly reduces the work performance and life of the electronic instruments. Thermal interface materials (TIMs) are placed in between heat generating micro-chip and the heat dissipater to conduct all the produced heat to the heat sink. Development of suitable TIMs with excellent thermal conductivity (TC) in both in-plane and through-plane directions is a very important need at present. For efficient thermal management, polymer composites are potential candidates. But in general their thermal conductivity is low compared to that of metals. The filler integration into the polymer matrix is one of the two approaches used to increase the thermal conductivity of polymer composites and is also easy to scale up for industrial production. Another way to achieve this is to change the structure of polymer chains, which fall out of the scope of this work. In this review, considering the first approach, the authors have summarized recent development in many types of fillers with different scenarios by providing multiple cases with successful strategies to improve through-plane thermal conductivity (TPTC) (K⊥). For better understanding of TC the comprehensive background is also presented. In the end, it is given a detailed conclusion which provides drawbacks of some filler, multiple significant routes recommended by other researchers to build Thermally Conductive Polymer Composites, future aspects along with direction so that the researchers can get a guideline to design an effective polymer based Thermal interface materials. A number of methods to improve the effective (out-plane) thermal conductivity of polymer composites are also discussed.

Ion-exchange membranes (IEMs) are widely used in desalination, waste water treatment, food, energy production and other applications. There is a strong demand for cost-effective IEMs characterized by high selective transport of ions of a certain sign of charge. In this paper, we simulate the experimental results of V. Sarapulova et al. (IJMS 2021) on the modification of an inexpensive anion-exchange membrane (CJMA-7, Hefei Chemjoy Polymer Materials Co. Ltd., China) with a perfluorosulfonated ionomer (PFSI). The modification was made in several stages including keeping the membrane at a low temperature, applying a PFSI solution on its surface, and subsequent drying it at an elevated temperature. We apply the known microheterogeneous model with some new amendments to simulate each stage of the membrane modification. It has been shown that the PFSI film formed on the membrane-substrate does not affect significantly its properties due to the small thickness of the film (4 m) and similar properties of the film and substrate. The main effect is caused by the fact that PFSI material “clogs” the macropores of the CJMA-7 membrane, thereby blocking the transport of coions through the membrane. In this case, the membrane microporous gel phase, which has a high selectivity to counterions, remains the primary pathway for both counterions and coions. Due to the above modification of the CJMA-7 membrane, the coion (Na+) transport number in the membrane equilibrated with 1 M NaCl solution decreased from 0.11 to 0.03. Thus, the modified membrane becomes comparable in its transport characteristics with more expensive IEMs available on the market.

We confirm that energy dissipation weighting provides the most accurate approach to determining the effective hydraulic conductivity (Keff) of a binary K grid. A deep learning algorithm (UNET) can infer Keff with extremely high accuracy (R2 > 0.99). The UNET architecture could be trained to infer the energy dissipation weighting pattern from an image of the K distribution with high fidelity, although it was less accurate for cases with highly localized structures that controlled flow. Furthermore, the UNET architecture learned to infer the energy dissipation weighting even if it was not trained on this information directly. However, the weights were represented within the UNET in a way that was not immediately interpretable by a human user. This reiterates the idea that even if ML/DL algorithms are trained to make some hydrologic predictions accurately, they must be designed and trained to provide each user-required output if their results are to be used to improve our understanding of hydrologic systems most effectively.

The efficiency, durability, and overall performance of a car engine are influenced by several critical factors. The quality and properties of engine oil play a crucial role, and oil is used in internal combustion engines for lubrication and cooling purposes. This research study aimed to compare the impact of fullerene-C60 (99.5%), Fe2O3, and TiO2 nanoparticles on the thermal properties of C.A.L.T.E.X. red engine oil with grades 10W30, 20W40, and 20W50. This study focused on the effect of a nanoparticle concentration of 0.01 wt.% in different engine oil grades at various temperature values of 30-120 ℃. The Nanofluids were prepared using the two-step direct mixing method, employing a magnetic stirrer and an ultrasonicator, ensuring uniform distribution of nanoparticles in the base fluids. The thermal conductivity, thermal diffusivity, and volumetric heat capacity of the base fluids and nanofluids were measured using the FLUCON LAMBDA thermal conductivity meter. Additionally, flash points were measured using the flash point tester. It was concluded that the thermal properties of TiO2 and Fe2O3 showed considerable enhancement; in contrast, Fullerene only showed the 212 ℃ flash point.

Flexibility of polymers defined by an equation in 2019 is related here to thermal conductivity, using reliable data for both properties found in the literature. The resulting equation is simple, it has the form of a quadratic polynomial. The goodness of the fit represented by R² = 0.975, while R² = 1 represents a perfect fit. Thus, knowledge of one of these properties can be used for calculation of the other one. The present results are a part of a larger program enabling obtaining by calculation pertinent properties of polymers from other properties for which data are available.

The conductor aluminum alloys Al-0.25wt.%Zr doped additionally with Х = Er, Si, Hf, and Nb were the objects of investigations. The fine-grained microstructure in the alloys was formed by Equal Channel Angular Pressing and Rotary Swaging. The thermal stability of the microstructure, specific electrical resistivity, and microhardness of the novel conductor aluminum alloys was investigated. The mechanisms of nucleation of the Al3(Zr,X) secondary particles during annealing the fine-grained aluminum alloys were determined using Jones-Mehl-Avrami-Kolmogorov equation. Using Zener equation, the dependencies of the mean secondary particle sizes on the annealing time were obtained on the base of analysis of the data on the grain growth in the aluminum alloys. The secondary particle nucleation during long-time low-temperature annealing (300 оC, 1000 hrs) was shown to go preferentially at the cores of the lattice dislocations. The Al-0.25%Zr-0.25%Er-0.20%Hf-0.15%Si alloy subjected to long-time annealing at 300 оC has the optimal combination of the microhardness and electrical conductivity (59.8%IACS, Hv = 480 ± 15 MPa).

The constant increase in current density in electrical wires leads to increasingly significant heat losses due to Joule effect. Therefore, reducing the electrical resistivity of copper wires becomes necessary. To achieve this goal, the development of a composite material incorporating a more conductive reinforcement, the graphene, is a promising way. The design of a copper/graphene composite using a powder metallurgy-based method is presented. This synthesis method allows for interface control through the growth of CuO(Cu) nanoparticles tightly bonded to the reinforcement. It also involves the dispersion of graphene through ultrasonic treatment and its alignment within the matrix using a uniaxial pressing densification method. The increase in the hardness (+12 HV) demonstrates the effective dispersion and separation of graphene layers. The impact on the electrical properties of dendritic copper (ρe = 2.30 µΩ.cm) remains limited, with a decrease in electrical resistance of approximately 1.4%. However, for copper with higher electrical resistivity, flake copper (at 2.71 µΩ.cm) and brass at (7.66 µΩ.cm), reductions of 2.7% and 10% have been achieved, respectively. With the improvement of graphene quality, there is more room to improve the electrical properties. This work paves the way for the development of composites with improved electrical resistivity.

Seyfe Lake is an important part of the natural ecosystem of Central Anatolia and lies within a 1487 km² closed basin. Groundwater withdrawal for irrigation and recent climatic change have caused lake area to decrease for decades and to completely disappear briefly in August 2008. Groundwater quality is crucial for sustainable irrigation in the Seyfe Basin. A key finding of this study is the difference in the Hardie-Eugster alkalinity-to-calcium ratio of the lake water and that of most groundwater wells in the basin. This difference in the chemical signature of Seyfe Lake and basin groundwater means the evaporative salinization pathway of most groundwater discharged into the lake cannot account for the composition of Seyfe Lake. The ratio of actual evapotranspiration to precipitation will increase under current climate change projections. A second finding, with implications for soil salinization, is that most groundwater in Seyfe Basin has a Hardie-Eugster alkalinity-tocalcium ratio greater than unity, meaning soil alkalization will accompany soil salinization.

The proton conductivity, phase composition and mechanical properties of (1-x)CsH2PO4–x fluoropolymer electrolytes (x-mass fraction, x=0-0.3) have been investigated firstly and discussed. UPTFE and PVDF-based polymers (F2M, F42, SKF26) with the high mechanical properties and thermal stability have been chosen as a fluoropolymer additive. According the XRD data, a monoclinic CsH2PO4 (P21/m) phase is retained in all compositions of the polymer electrolytes studied. The conductivity of (1-x)CsH2PO4-x fluoropolymer in the high-temperature phase decreases by approximately one order of magnitude compared with the pure CsH2PO4 for x~0.15-0.20. The size and shape of CsH2PO4 particles and their distribution have been shown to affect significantly the proton conductivity and mechanical properties of the membranes. The thin-film composite systems were produced by various methods of the obtaining salt particles, their mixing and applying to a polymer matrix. The uniform distribution of particles in the polymer systems with the size of ~300 nm was achieved by a pretreatment of the suspension in a bead mill. CsH2PO4-based mechanically strong membranes with the thickness ~50–100 μm were obtained for the soluble fluoropolymers (F2M, F42, SKF26). With an increase in the mass fraction of the polymer the ability of the membranes to resist the plastic deformation and the mechanical strength increases and comparable to the best low temperature membranes. The proton-conducting membranes (1-x)CsH2PO4 – x fluoropolymer with the optimal combination of the conductivity, mechanical and hydrophobic properties are promising for use in solid acid fuel cells.

Electrical properties of the thin films of poly(arylene ether ketone) copolymers (co-PAEKs) with the fraction of phthalide-containing units of 3, 5 and 50 mol% in the main chain were investigated by using radiation induced conductivity (RIC) measurements. Transient current signals and current-voltage (I-V) characteristics were obtained under exposing 20÷25 thick films of the co-PAEKs to monoenergetic electron pulses of the energy ranged from 3 to 50 keV in the electric field ranged from 5 to 40 V/μm. The Rose-Fowler-Vaisberg semi-empirical model based on a multiple trapping formalism was used for an analysis of the RIC data and the parameters of the highly dispersive charge carrier transport were evaluated. The analysis revealed that charge carriers moved in isolation from each other and the applied electric fields were below the threshold field triggering the switching effect (a reversible high-to-low resistivity transition) in the co-PAEK films. It was also found that the co-PAEK films due to the super-linear I-V characteristics are highly resistant to electrostatic discharges arising from the effects of ionizing radiation. This property is important for the development of protective coatings for electronic devices.

Knowing the spatial variability of factors that influence crop yield is essential to carry out a localized treatment. The present study aimed to map the spatial variability of apparent soil electrical conductivity (ECa) in two cultivation areas, delimit management zones (MZ), characterize the soil density (Sd) at two depths, in each MZ, and assess whether the delimitation of MZ, based on the spatial variability of ECa, was able to identify regions of the productive field with different Sd. Spatial variability of ECa was detected. MZ with the highest mean value of ECa also presented the highest mean values of Sd. The highest Sd values were observed for the 0.1 – 0.2 m layer, regardless of the studied area. Regardless of granulometry, the proposed method was able to detect density differences from ECa. The delimitation of MZ, based on the spatial variability of ECa mapping, was able to differentiate the mean values of Sd between MZ 1 (1.53 g cm-3) and MZ 2 (1.67 g cm-3) in the Area A, in the 0.1 – 0.2 m layer. A statistical difference was observed for the mean values of Sd, in MZ 1, layer 0.1 - 0.2 m, when comparing the two study areas: A (1.53 g cm-3) and B (1.64 g cm-3). We suggest that further studies should be carried out, as the mapping of the spatial variability of the apparent soil electrical conductivity showed potential in the differentiation of soil bulk density at different depths.

Electrically conductive adhesives (ECA’s) are used widely to replace or reinforce lead soldering or conductive metal components in electronic packaging applications such as die attachment, solderless interconnections, component repair, display interconnections, and heat dissipation. Their conductive behavior as well as the associated behaviors such as heat conduction and mechanical behavior (strength, rigidity, deformation and viscoelastic behavior, which may be affected by moisture ingression) are affected by adhesive film thickness, volume fraction, size and shape of the conductive filler, as well as uncured base adhesive viscosity, substrate and filler surface treatment and the applied pressure (during bonding and during conduction). The adhesive resistivity decreases precipitously above a characteristic filler volume fraction called the percolation threshold. In general, micron-sized metal fillers mixed in an adhesive (often an epoxy) resulting with different film thicknesses exhibit thickness thresholds for transition from three-dimensional conductivity to two-dimensional conductivity with considerable increases in thickness-direction (z-axis) resistivity when the film thicknesses are smaller than these threshold values. Recently, the use of conductive nanoparticles allowed decreases in percolation threshold levels as well as increases in mechanical strength and durability of ECA’s. Most ECA’s are supplied in liquid or paste form in varying viscosities and therefore, the method of their application also affects their performance. This work intends to provide an understanding of these effects on conduction behavior in (usually high-priced) equipment in which they are used.

The subject of this article is the dynamics of water in a soil pedostructure sample whose internal environment is subjected to a potential gradient created by the departure of water through surface evaporation. This work refers entirely to the results and conclusions of a fundamental theoretical study focused on the molecular thermodynamic equilibrium of the two aqueous phases of the soil pedostructure. The new concepts and descriptive variables of the hydro-thermodynamic equilibrium state of the soil medium, which have been established at the molecular level of the fluid phases of the pedostructure (water and air) in a previous article, are recalled here in the systemic paradigm of hydrostructural pedology. They allow access to the molecular description of water migration in the soil and go beyond the classical mono-scale description of soil water dynamics. We obtain a hydro-thermodynamic description of the soil's pedostructure at different hydro-functional scale levels including those relating to the water molecule and its atoms. The experimental results show a perfect agreement with the theory, validating at the same time the systemic approach which was the framework.

Silver iodide (AgI) is a system prototype allowing the flow of ions through its structure and has a phase transition at 420 K, characterized by an abrupt change in conductivity and a high ionic conductivity. Introducing low concentrations of graphite (C) into the AgI structure produces a new material with a mixed conductivity (ionic and electronic) which increases with increasing temperature. The experimental results of the logarithm of the ionic conductivity as a function of the inverse of temperature for the (AgI)x–C(1−x) system for low carbon concentrations 0.97 ≤ x ≤ 0.99 were well fitted using a phenomenological model with a probability distribution for the charge carriers based on the carrier density

In this research the possibility of using pH change to measure proton conductivity of proton exchange membranes (PEM) or else known as polymer electrolyte membranes are tested with using an experimental setup prepared by using pH meters. PEMs are an important part of the fuel cells and proton conductivity of the PEMs are one of the most important properties of the PEMs. Also, proton conductivity is the one of the biggest limiting factors of fuel cells thus it is important to measure the proton conductivity of the PEMs while trying new polymers or new types of membranes. But as current measurement methods do not have a standard and can be separated into mainly two different measurement methods which are Electron Impedance Spectroscopy (EIS) and Ion Exchange Capacity (IEC). EIS gives clearer results, but it needs an impedance analyzer machine, platinum electrodes and setup so this cannot be possible for every researcher due to its economical aspect. For IEC it is basically a titration method to see acid groups in the polymer or polymer matrix which are directly responsible for proton conductivity so this can show an indirect measurement of proton conductivity. But as for this one drawback are firstly this one is an indirect measurement and secondly needs overnight bath in solution can take long times. So, the possibility of using pH can be easier and both from time and economical aspect if it can be proven the give a direct relationship between pH change and proton conductivity.

This study presents an experimental investigation of the convective drying process of ginger rhizomes (Zingiber officinale). It analyses the effect of moisture content on the thermal properties of dried ginger rhizomes. Drying experiments were conducted under controlled conditions to establish the relationship between moisture content and thermal conductivity. The drying kinetics were examined to provide insights into the drying behaviour of ginger rhizomes and the influence of moisture content on their thermal properties. The results demonstrated a significant impact of initial moisture content and convective drying conditions on the drying process. As drying progressed, the moisture content decreased, leading to a reduction in thermal conductivity. It was observed that drying under convective drying takes 24 hours compared to open sun drying at nine days and solar tunnel drying at eight days. The drying temperature of 60°C was considered optimum. The results show that dried ginger at an absolute moisture content of 6.63% (wb) with a thermal conductivity of 0.0553W/m. K for unblanched ginger, 9.04% (wb) with thermal conductivity of 0.0516W/m. K for blanched ginger, 8.56% (wb) moisture content with a thermal conductivity of 0.0483W/m. K for peeled ginger and 5.98% moisture content with a thermal conductivity of 0.0460W/m. K for unpeeled ginger would be ideal for making powdered ginger rhizomes. These findings have practical implications for the food industry, as they can aid in designing and improving drying processes for ginger rhizomes and similar agricultural products. By understanding the relationship between moisture content and thermal properties, more efficient drying strategies can be developed to minimise energy consumption and maintain the quality of the dried product.

The CuCrSn alloy is promising as high-strength and high-conductivity Cu alloy due to its relative low smelting requirement, while thus far reports on the CuCrSn alloy is still quite lacked. In this study, the microstructure and properties of Cu-0.20Cr-0.25Sn (wt%) specimens prepared under different rolling and aging combinations were comprehensively characterized, in order to reveal the effects of cold rolling and aging on the CuCrSn alloy. The results show that increasing the aging temperature from 400 ºC to 450 ºC can obviously accelerates the precipitation, and the cold rolling before aging significantly increases the initial microhardness and promotes the precipitation. Whereas, the deformation hardening will be eliminated during the aging process, making the microhardness even decrease monotonically when the aging temperature and the rolling ratio before aging are high. Performing the cold rolling after the aging can maximize the effects of precipitation strengthening and deformation strengthening, and its adverse impact on the conductivity is not serious. A tensile strength of 506.5 MPa and a conductivity of 70.33% IACS were obtained with such a treatment, only the elongation decreases. Different strength-conductivity combinations of the CuCrSn alloy can be achieved through appropriate combinations of the aging and post aging cold rolling conditions.

The purpose of this study is to identify the steps involved in fabricating silica/chitosan composite membranes and their suitability in fuel cell application. It also intends to identify the physical characteristics of chitosan composite membranes, including their degree of water absorption, proton conductivity, methanol permeability, and functional groups. In this investigation, composite membranes were fabricated using the solution casting method with chitosan content of 5 g and silica variations dosage of 2% and 4% while stirring at a constant speed for 2h. According to the findings, the analysis of composite membranes produced chitosan membranes that were successfully modified with silica. The optimum membrane was found to be 4% s-SiO2 from the Sol-gel method with composite membrane's optimal condition of 0.234 cm/s proton conductivity, water uptake of 56.21%, and reduced methanol permeability of 0.99 × 10 -7 cm2/s in the first 30 minutes and 3.31 × 10-7 in the last 150 minutes. Maintaining lower water uptake capacity at higher silica content is still a challenge that needs to be addressed. However, the fabricated membranes showed exceptional results in terms of proton conductivity and methanol permeability.

The blended perfluorinated sulfonic acid ionomers are prepared to have equivalent weight (EW) ~1000, 980, and 830. The catalyst layers (CLs) using blended PFSA ionomers with different side chain lengths and EWs are investigated, compared to the CLs utilizing single ionomers. The IEC results indicate that the blended ionomers have the targeted EWs. As a result, it is found that the blended ionomers exhibit higher ion conductivity than the single ionomers at all temperatures due to higher water uptake of the blended ionomers. Even though they have a similar EW, it implies that the blended ionomers have bulk structure to form competent free volume. The blended ionomers with short side chain (SSC) and low EW can help reduce the activation energy due to the enhanced hydrophobic and hydrophilic segregation. In addition, it is observed that the catalyst layers using the blended ionomer form more porous microstructure to help reduce the resistance of oxygen transport and attributes to lower mass transfer loss. This effect is significantly revealed in the fuel cell operation at not the lower temperature (70 °C) and full humidification (100%) but the elevated temperature (80 °C) and lower relative humidity (50 and 75%). The blended ionomer-based catalyst layers with higher water uptake and porous CL structure result in higher fuel cell performance and better mass transport than the single ionomer-based catalyst layers.

We demonstrate that the conductivity of graphene on thin-film polymer substrates can be accurately determined by reflection-mode air-plasma-based THz time-domain spectroscopy (THz-TDS). The phase uncertainty issue associated with reflection measurements is discussed, and our implementation is validated by convincing agreement with graphene electrical properties extracted from more conventional transmission-mode measurements. Both the reflection and transmission THz-TDS measurements reveal strong nonlinear and instantaneous conductivity depletion across an ultra-broad bandwidth under relatively high incident THz electrical field strengths.

A formula for the turbulent Prandtl number is derived in terms of local variables available from two-equations turbulence models. The derivation is a direct consequence of the expected square additivity of the molecular and turbulent parameters defining the effective viscosity and the effective conductivity. The formula does not degenerate and leads to a Kays like formulation if approximated. Its utility and its limitation are discussed.

CSZM compounds were synthesized by dry chemistry route with 5, 10, and 15% dopant of Mg dopants in the Ce 0.8-2x Sm 0.2 Zrx Mgx O2-d, {x = 0.05, 0.1 &0.15}. The newly investigated materials were physically, chemically, and electrochemically studied and have shown promising results. The CSZM was crystalized in a fluorite structure with a pure cubic phase in a space group Fm3m and cell parameter a = 5.401742 °A and theoretical density from 7.6 to 8.9 after firing in the air with a final temperature of 1400 °C. characterization of the structure and indexing of electrolyte materials were made after X-ray diffraction (XRD) testing. A Scanning electron microscope (SEM) morphological analysis was used to examine the microstructure details. Electronic impedance spectroscopy (EIS) measurements were achieved from 400 °C to 700 °C showing the highest value of conductivity of 1.0461 x 10+1 S/cm at 700 °C while the minimum value was 2.7329 x 10-2 S/cm at 400 °C and the total activation energy was found (Ea) 0.6865 eV under 5% H2/Ar.

The results of studying the effect of particles of few-layer graphene (FLG) synthesized by self-propagating high-temperature synthesis (SHS) on the complex of strength and thermo physical properties of polymer composite products obtained by DLP 3D printing are presented. It has been discovered to achieve an increase in thermo physical and strength parameters of polymers modified by FLG compared with samples made on the unmodified base resin. This result was achieved due to low defectiveness, namely the absence of Stone-Wales defects in the structure of FLG due to the homogeneous distribution of FLG over the volume of the polymer in the form of highly dispersed aggregates. It was possible to increase hardness by 120 %, bending strength by 102 %, Charpy impact strength by 205 %, and thermal conductivity at 25 °C by 572 % at concentrations of few-layer graphene of no more than 2 wt. %.

Water is an essential commodity to sustain life. The condition of water in Tiruchirappalli was measured using different Physicochemical parameters like Temperature, pH, TDS, Total Solids, Salinity, Total Hardness, and Electrical Conductivity. Water samples were collected from different places in Tiruchirappalli city, Tamil Nadu. Water samples were examined by different chemical methods. According to the results, Thiruvarambur-1 showed comparatively higher results in the case of every parameter compared to other sampling stations. Obtained results were further interpreted using statistical tools. Considering ECs as a principal component for the regression and correlation analysis with other parameters significant correlation was found. A strong correlation was observed between ECs and TDS, Total Hardness, Turbidity, and Salinity.

The current study aimed to evaluate the influence of different sintering temperatures on the properties of copper aluminum oxide (CuAlO₂) pellets synthesized from copper oxide (CuO) and aluminum hydroxide (Al(OH)₃) for application in smart infrastructure systems. The pellets were sintered at 400 K, 1000 K, and 1300 K, in the presence of nitrogen gas flow to reduce the amount of oxygen availability. The CuAlO₂ sintered nanoparticles were chemically analyzed by X-ray diffractometry, and the nanostructure of the materials was studied by scanning electron microscopy. The transmittance of the sintered materials was examined by ultraviolet/visible (UV/Vis) spectrophotometry, and 88% transparency was observed for the pellets sintered at 1300 K. Electrical conductivity was measured at 0.905 mS/cm, indicating a semiconducting behavior.

The global context of research for new sustainable energy storage technologies makes it a very active sector with significant scientific and economic challenges. Indeed, due to the irregular development of renewable energies and the shutdown of traditional power facilities, it is difficult to maintain a stable balance in terms of supply and demand: energy storage can help in particular for substantial changes in the latter. Metal air batteries have a higher energy density and are safer than other available energy storage devices. Based on the existing and proven lead-acid battery technology, this paper proposed an open cell foam manufactured by the Excess Salt Replication process for use as an anode for lead-air battery cellsies with sulphuric acid as the electrolyte. This will save lead and reduce the battery weight. A 25% antimonial lead alloy was used to produce open cell foams with a cell diameter between 2 mm and 5 mm for the antimonial lead-air battery. Preliminary results of the effective electrical conductivity of self-discharged primary battery cells, measured experimentally, showed that all antimonial lead foam-air battery cellsies performed better than that made from the same dense non porous antimonial lead alloy. This is generally due to their important specific surface area where oxidation-reduction reactions took place. A correlation between the effective electrical conductivity and the cell diameter has been established and the highest conductivity was obtained with a cell diameter of 5mm. The feasibility of such an electrical system has been demonstrated.

Using number theory, a formula is obtained that describes the thermal conductivities of ZrC, UC, UN, ThN, ZrN and Th_xU_1-xN at x = 0.2 and 0.5 with temperature change. This formula contains the atomic numbers of the elements, the thermal conductivities of the individual elements of the substance, and the structural parameter. There is no direct dependence on temperature in the formula, since it is hidden in the thermal conductivities of each element and in the structure parameter. In some temperature ranges, the structural parameter is constant; therefore, the thermal conductivity of some carbides and nitrides is expressed through summing the thermal conductivities of individual elements.

This study endeavors the preparation and evaluation of Phenol Furfural Resin (PFR) from bagasse and its nanocomposites for Electrically Conductive Adhesives (ECAs) application. PFR was prepared with the furfural extracted from bagasse using modified acid digestion method. Three different formulations of PFR nanocomposites with conductive nanoparticles i.e., PFR-silver, PFR-graphite, and PFR-silver + graphite were prepared using 20-60 w/w% of fillers via impregnation method. Resultant products were characterized by FT-IR, SEM, EDS and XRD spectroscopy. Electrical conductivity was measured using four probe technique while band gap was calculated via Tauc plot. Virgin PFR has shown poor conductivity up to 2.6 × 10^-4 Scm^-1 while the highest conductivity achieved was 8.2 × 10^-1 Scm^-1 for nanocomposite constituted silver, graphite, and PFR with 40:30:20 ratios respectively. This synergism was exhibited because graphite and Ag NPs supply excellent junctions for building networks. Both tend to coalesce due to van der Waals forces and high surface energies, therefore conductive pathways numbers can be increased, and contact area can be effectively enlarged. This ternary composite has exhibited the lowest bandgap energy value i.e., 3.1 eV. Thermogravimetric temperatures T₀ and T_deg values were increased up to 120 °C and 484 °C respectively, showing significant increase in thermal stability. Therefore, the resultant nanocomposite material has good potential to be employed as ECAs in electronic industry.

The development of good conductivity p-type β-Ga2O3 is critical to realize its devices and applications. The nitrogen-doped p-type β-Ga2O3 films with enhanced conductivity characteristics were prepared through the thermal oxidation of GaN in the N2O atmosphere. Further measurements were performed on the oxidized films at 1000, 1050, and 1100 °C to have insight into the underlying mechanism of the thermally activated transformation process. The room temperature photoluminescence (PL) spectra demonstrated a moderate ultraviolet emission peak at 246 nm, confirming the generation of gallium oxide with a band gap of ~5.0 eV. The normalized X-ray diffraction (XRD), the high-resolution transmission electron microscopy (HRTEM), and the selected area electron diffraction (SAED) patterns were used to confirm the characteristic of polycrystalline and anisotropic growth. Then, the effects of the oxidation temperature on the amount of incorporated nitrogen were analyzed using secondary ion mass spectrometry (SIMS). Moreover, the ionization energy of the acceptor of films oxidized at 1000, 1050, and 1100 °C was calculated and analyzed using the temperature-dependent Hall test results. The results showed that nitrogen doping was the main contributor to p-type electrical properties. The activation energy of the polycrystalline β-Ga2O3 prepared through thermal oxidation of GaN in the N2O atmosphere was estimated to be 147.175 kJ·mol-1 using the Arrhenius plot, which was considerably lower than that of both dry and wet oxidations of GaN in O2 ambient, thus confirming the efficiency of thermal oxidation of GaN in N2O.

A novel manufacturing process is presented for producing Nano powders and thin films of CuCoO₂ (CCO) material. This process utilizes three cost-effective synthesis methods: hydrothermal, sol-gel, and solid-state reactions. The resulting delafossite CuCoO₂ samples were deposited onto transparent substrates through spray pyrolysis, forming innovative thin films with a Nano crystal powder structure. Prior to the transformation into thin films, CuCoO₂ powder was first produced using a low-cost approach. The precursors for both powders and thin films were deposited onto glass surfaces using a spray pyrolysis process, and their characteristics were examined through X-ray diffraction, scanning electron microscopy, HR-TEM, UV-visible, and Electrochemical impedance spectroscopy (EIS) analyses was conducted to determine the conductivity in transversal direction of this groundbreaking material for solar cell applications. On the other hand, the sheet resistance of the samples was investigated using the four probe-method to obtain the sheet resistivity and them calculate the in plane conductivity of the samples. We also investigated the aging characteristics of different precursors with varying durations. The functional properties of CuCoO2 samples were explored by studying chelating agent and precursor solution aging periods. Resuming, this study thoroughly discusses the synthesis of delafossite powders and their conversion into thin films, which hold potential as hole transport layers in transparent optoelectronic devices.

The structure and phenomena arising from charge transfer in cold field emission modus in a single closed carbon nanotube under cold field emission conditions were studied. By studying microphotographs in various microscopes - AFM, SEM, TEM it was found inhomogeneities in the form of two types of superlattices. The conductivity of the emitter section of a nanodiode circuit with an emitter made of an individual closed carbon nanotube (CNT) and arrays of closed CNTs was studied. High values of cold field emission were observed, as well as nonlinearity and anomalies of the current-voltage characteristic (I-V characteristics), which manifested themselves in the form of peaks at low and high current values. Peaks in the CVC have distinct areas of negative differential conductivity. It is argued, that the anomalously high currents in the I–V characteristics of cold field emission of electrons from a nanoemitter made of closed CNTs can be associated with a sharp increase in the density of electron states at energies near the van Hove singularity.

This study examines the effects of particle size and heat pipe angle on the thermal effectiveness of a cylindrical screen mesh heat pipe using silver nanoparticles as the test substance. The experiment investigates three different particle sizes (30nm, 50nm, and 80nm) and four different heat pipe angles (0°, 45°, 60°, and 90°) on the heat transmission characteristics of the heat pipe. The results show that the thermal conductivity of the heat pipe increased with an increase in heat pipe angle for all particle sizes, with the highest thermal conductivity attained at a 90° heat pipe angle. Furthermore, the thermal resistance of the heat pipe decreased as the particle size decreased for all heat pipe angles. The thermal conductivity measurements of the particle sizes - 30, 50, and 80 nm - were 250 W/mK, 200 W/mK, and 150 W/mK, respectively. The heat transfer coefficient values for particle sizes 30nm, 50nm, and 80nm were 5500 W/m2K, 4500 W/m2K, and 3500 W/m2K, respectively. The study also found that the heat transfer coefficient increased with increased heat pipe angle for all particle sizes, with the highest heat transfer coefficient obtained at a 90° heat pipe angle.

As sessile organisms, plants face a wide range of abiotic stresses, with salinity being a prominent constraint affecting their growth, development, and productivity, particularly in arid and semi-arid regions. This study focused on understanding how salinity impacts Jatropha curcas, an important oilseed plant for biodiesel production. By examining the anatomy and ultrastructure of stomata and chloroplasts, we investigated the effects of prolonged salinity stress on J. curcas. This stress led to changes in stomatal density, stomatal index, and ostiole aperture, which case an imbalance of water conductivity in the xylem. Through transmission electron microscopy, we explored the subcellular organization of J. curcas chloroplasts and their contribution to plant photosynthetic efficiency, providing insights into their role in this process. Notably, salinity treatment resulted in a significant increase in starch granules accumulation, leading to impaired the granal and stromal grana lamellae, destroying this ultrastructure. Our findings indicate that the anatomy and ultrastructure of chloroplasts play a crucial role in influencing photosynthetic efficiency and hydraulic conductivity. This study offers new perspectives on the structure and function of chloroplasts in J. curcas, presenting innovative opportunities to develop strategies that enhance biofuel production in areas with high soil salinity.

The analysis of high-temperature physicochemical properties of theK₃AlF₆-Na₃AlF₆-AlF₃ molten salt system is crucial for practical production of electrolytic aluminum. In this paper, the physicochemical properties of the K₃AlF₆-Na₃AlF₆-AlF₃ molten salt electrolyte system at 1173 K and standard atmospheric pressure were simulated using molecular dynamics calculations. The effects of Zr、B、C、W、Ti、Hf、Nb、and Ta on the radial distribution function, coordination number, viscosity and conductivity of the electrolyte system are discussed in detail. The simulation results show that the coordination number between Al-F and the conductivity is decreasing as the content of B²- increases. And the coordination number between Al-F and the viscosity is decreasing as the content of Zr⁴⁺ increases. With the addition of impurity elements such as C, W, Ti, Hf, Nb, and Ta, the data show that C has no significant effect on this electrolyte system, while the presence of W will decrease the coordination number between Al-F in the system. The presence of Ti, Hf, Nb, and Ta may intensify the decomposition reaction between one of the Al-F ligands, which increases the coordination number between Al-F and the number of ions in the electrolyte. This work provides theoretical support for the subsequent study of inert anodes containing Zr, B, Ti, Hf, Nb, and Ta.

The phenomena of electrical conductivity and electromigration in metallic systems are related, since in both cases the basic physical process is the scattering of conduction electrons by metal ions. Numerous searches have been made for equations connecting the conductivity with electromigration. In the case of a liquid metal, when using the Drude-Sommerfeld (DS) conduc-tivity equation, it was not possible to obtain a quantitative relationship between these phenomena, which would be correct. Attempts to find such a relationship when taking into ac-count the N. Mott correction (g - factor) in the DS equation were unsuccessful. This article proposes a different correction (b - factor) to the DS equation, which takes into account the pos-sibility of varying the momentum transferred by the conduction electron to a metal ion during the scattering. This correction allows to establish a quantitative relationship between conductivity and electromigration, as well as between electromigration in various binary systems with common components, in agreement with experiment. The proposed theory describes well, in particular, two- and multi-component metal systems of any concentration (the consistency rule for triangles A-B, B-C, C-A). The value of b - factor smoothly changes depending on the heat of vaporization of the metal, per unit volume.

In this work, three different types of sandwich structures were manufactured using Formica sheet (a paper-based sheet) as skin and perlite/sodium silicate foam as core with/without the paper honeycomb. The sandwich structures were fabricated by attaching Formica sheets on both sides of the honeycomb, perlite/sodium silicate foam, and perlite/sodium silicate foam-filled honeycomb core panels. The flexural characteristics were studied by a three-point bending test and the thermal conductivity was measured using Lee’s thermal conductivity apparatus. The results demonstrated a significant improvement in flexural properties, including core shear stress, facing stress, bending stress, and energy absorption, when incorporating the paper honeycomb reinforcement. The thermal conductivity and flexural properties were found to be well-compatible with the existing building materials for similar applications in the literature. The failure investigation revealed that the sandwiches with paper honeycomb only prematurely failed due to core buckling, whereas the foam-filled honeycomb core-based sandwiches were able to sustain higher loads, exhibiting material failures such as core shear failure, skin rapture, and delamination. It is found that the foam-filled paper honeycomb sandwich structures can withstand higher bending loads compared to foam core-based and paper honeycomb-based sandwich structures. These developed sandwiches offer potential as green materials due to the characteristics of their constituent materials and can find valuable applications in the building thermal insulation.

Many studies on magnetorheological fluid (MRF) have been carried out over last three decades several salient advantages such as fast phase change, easy control of the yield stress and so forth. Especially, several review articles of MRF technology have been reported for last two decades summarizing the development of MRFs and their applications. As specific examples, the review articles including the optimization of the particles and carrier liquid to achieve minimum off-state viscosity and maximum yield stress at on-state, the formulation of many constitutive models in-cluding Casson model and Herschel-Bulkley (H-B) model, the sedimentation enhancement using additives and nanosized particles, many types of dampers for automotive suspension and civil structures, medical and rehabilitation devices, MRF polishing technology, the methods of mag-netic circuit design, and the synthesis of various controllers have been published. More recently, the effect of the temperature and thermal conductivity on the properties of MRFs and application systems are actively being investigated by several works. However, there is no review article on this issue so far despite of that the thermal problem is one of crucial factors to be seriously con-sidered for the development of advanced MRFs and commercial products of application systems. In this work, studies on the thermal conductivity and temperature in MRFs themselves and tem-perature-dependent application systems are reviewed, respectively, and principal results are summarized emphasizing on the followings: how to reduce the temperature effect on the field-dependent properties of MRFs and how to design application system to minimize the thermal effect. It is noted here that the review summary is organized in a chronological format using tables.

Natural laterite fixed-bed column intercalated with activated carbon prepared from Balanites ae-gyptiaca (BA-AC) was used for As(III) removal from an aqueous solution. Investigations were carried out to solve the problem of column clogging which appears during water percolation through the column. Experimental tests were conducted to evaluate the hydraulic conductivity and the effects of various parameters such as grain size, bed height, and initial As(III) concentra-tion. The breakthrough increased from 15 to 85 h with the increase of the bed height from 20 to 40 cm, and decreased from 247 to 32 h with the increase of initial As(III) concentration from 0.5 to 2 mg/L. The permeability data showed that the fixed-bed column filled with laterites layers intercalated with activated carbon performs much better than the non-intercalated adsorbent col-umn. The Bohart-Adams model showed that increasing the bed height induced a decrease in kAB and N0 values. The critical bed depths determined using the bed depth service time (BDST) mod-el for As(III) removal were 15.23 and 7.98 cm for 1 and 20% breakthrough, respectively. The re-sults showed that the new low-cost filtration system, based on laterite layers alternated with BA-AC layers, could be used for the treatment of arsenic-contaminated water.

The results of experimental studies of ohmic conductivity degradation in the ensembles of nanostructured anatase bridges under long-term effect of direct current are presented. Stochastic sets of interelectrode partially conducting bridges consisting of close-packed anatase nanoparticles were formed by the seeding particles from drying aqueous suspensions on the surfaces of silica substrates with interdigital platinum electrodes. Multiple-run experiments at room temperature have shown that ohmic conductivity degradation in these systems is irreversible. It is presumably due to accumulated capture of conduction electrons by deep traps in anatase nanoparticles. The scaling analysis of voltage drops across the samples at the final stage of degradation gives a critical exponent for ohmic conductivity as 1.597. This value satisfactorily agrees with the reported model data for percolation systems. At an early stage of degradation, the spectral density of conduction current fluctuations wihin the frequency range of 0.01 Hz - 1 Hz decreases approximately as , while near the percolation threshold the decrease trend changes to . This transition is interpreted in terms of an increasing contribution of blockages and subsequent avalanche-like breakdowns of part of the local conduction channels in the bridges into electron transport near the percolation threshold.