Reduction In Resistance Research Articles

Recent Advances in Biomimetic Methods for Tillage Resistance Reduction in Agricultural Soil-Engaging Tools

The high tillage resistance of agricultural soil-engaging tools (TASTs) in farmland operations (e.g., tillage, sowing, crop management, and harvesting) increases fuel consumption and harmful gas emissions, which negatively affect the development of sustainable agriculture. Biomimetic methods are promising and effective technologies for reducing the TASTs and have been developed in the past few years. This review comprehensively summarizes the typical agricultural soil-engaging tools (ASETs) and their characteristics and presents existing biomimetic methods for decreasing TASTs. The introduction of TAST reduction was performed on aspects of tillage, sowing, crop management, and harvesting. The internal mechanisms and possible limitations of current biomimetic methods for various ASETs were investigated. The tillage resistance reduction rates of ASETs, as affected by various biomimetic methods, were quantitatively compared under different soil conditions with statistical analyses. Additionally, three future research directions were recommended in the review to further reduce TASTs and encourage the development of sustainable agriculture.

Copper‐graphene coatings for improving thermal shielding of CFRPs through electrodeposition techniques

AbstractToday, carbon fiber reinforced plastics (CFRPs) are materials of interest several industrial sectors because of their mechanical properties and low weight. However, applications in high‐temperature areas are limited because of thermal degradation. Thus, thin coatings acting as thermal shielding and ensuring the upkeep of CFRP structural stiffness are of high interest. This work presents an innovative approach to produce copper/graphene bilayer coatings through electrodeposition and electrophoretic deposition; it consists of laser pre‐treatment of the composite surface to remove the matrix layer exposing the carbon fibers, enabling the subsequent deposition. Bi‐layer graphene/copper coatings exhibit an enhancement in copper electrodeposition efficiency of more than 59% resulting in a 97% stiffness improvement compared to the single layer copper electroplating. All the obtained coatings were able to act as a thermal shield of the CFRPs, reducing the maximum temperature of the composite by more than 60%. In particular, due to the synergistic effect of copper and graphene, the GNPs‐Cu coating achieved the highest maximum temperature reduction (81%). Cross‐sectional analysis indicates severe delamination in uncoated CFRPs, whereas double‐layer coatings maintain structural integrity and prevent delamination even under high‐energy exposure. In addition, the coated composites exhibit a higher electrical conductivity compared to the laser cleaned CFRP, with the GNPs‐Cu coating that obtained a 90% enhancement because of the outstanding electrical properties of copper and graphene.Highlights The laser cleaning pretreatment allows the electrodepositions on CFRPs. The GNP‐Cu scenario achieves the highest deposition efficiency. A 97% stiffness improvement was achieved by GNPs‐Cu scenario. GNPs‐Cu coatings exhibit the utmost reduction in resistivity (98%). The GNPs‐Cu coating achieves the highest thermal shielding performance (81%).

The effect of silane‐modified carbon black and nano‐silica, individually and in combination, on the performance of ethylene–propylene–diene monomer rubber

AbstractThis study assesses the effectiveness of a specially developed surface‐modified carbon black, both on its own and in combination with nano‐silica, as a hybrid filler for ethylene–propylene–diene monomer (EPDM) rubber compounds. The modification process, which included treatment with a silane coupling agent, resulted in enhanced curing characteristics. The ∆Torque values for compounds incorporating the modified carbon black exceeded those of other formulations by 25.85%. Scanning electron microscopy (SEM) analysis demonstrated improved filler dispersion and better compatibility between rubber and filler due to the surface modification. The silane‐modified carbon black showed considerable enhancements in mechanical properties, particularly in tear resistance, with increases in tensile and tear strength of 22.46% and 34.86%, respectively, following surface treatment. Dynamic mechanical analysis (DMA) indicated the influence of both surface modification and filler type, revealing that the combination of modified carbon black and nano‐silica achieved a reduction in rolling resistance of 20.41% and enhanced ice and wet grip performance by 7.95%. Additionally, modified carbon black displayed varying effects on the glass transition temperature. Thermal gravimetric analysis (TGA) confirmed that the thermal stability of the compounds was consistent, while solvent resistance improved with surface modification, as shown by swelling ratios. Thermodynamic analysis indicated that the surface modification of carbon black positively influences the elasticity and chain mobility of the rubber compounds studied. In conclusion, the careful selection and optimization of filler materials and their modifications are essential for customizing the properties of rubber compounds to satisfy specific performance criteria and applications.Highlights Promising EPDM compounds were prepared with Silane‐Modified CB and Nano‐Silica. Silane‐modified CB effectively improved the curing properties of the EPDM compound. The ΔTorque and cross‐link density of modified CB/EPDM show the highest value. Modified CB/Nano‐Silica/EPDM exhibited significant improvement in tear strength. Modified CB/Nano‐silica/EPDM have lower rolling resistance and higher wet grip.

Thermal management performance of a novel elliptically grooved flat heat pipe system embedded with internally cooled condenser

Flat heat pipes (FHPs) with rectangular groove wick structures fail to sufficiently uplift the working fluid’s liquid meniscus to cover the upper sides of the groove walls due to the vertically flat wall design. This results in the formation of non-evaporative zones, particularly in the evaporator region, leading to elevated wall temperatures at high heat loads. To address this issue, a novel FHP with elliptical grooves as wick is designed and tested across heat loads ranging from 30 to 360 W. Elliptical groove depths of 0.5 mm and 0.7 mm are evaluated and compared to FHPs with rectangular grooves. Results showed that at 360 W, the 0.7 mm depth elliptical grooves resulted in 6.5 % reduction in evaporator wall temperature and 27.8 % reduction in thermal resistance, along with 31.5 % enhancement in effective thermal conductivity compared to rectangular grooves. The curvature of the elliptical grooves, combined with enhanced surface tension effects of the working fluid, efficiently uplifted the liquid meniscus to cover the upper wall of the groove, minimizing non-evaporative zones. Additionally, FHPs with elliptical grooves demonstrated lower entropy generation, indicating higher thermal efficiency. Consequently, FHPs with elliptical groove designs are concluded to be an efficient and suitable solution for the thermal management of miniaturized electronic devices.

Indentation parameters and corrosion resistance of explosive welded S30400/Q345R clad plates with heat treatment cycles

This study aims to clarify the indentation parameters and corrosion resistance of explosive welded S30400/Q345R clad plates with heat treatment cycles. A series of tests on the mechanical properties of the clad plate in the unseparated state of clad material (CM) and base material (BM) and its free surface corrosion resistance, as well as their evolution with stress relief heat treatment are studied and discussed. The results show that the severely carburised layer (SCL) that occurs on the stainless steel side of the heat treatment was the peak hardness of the entire clad plate, which was significantly reduced after four heat treatments. The worst mechanical performance was observed in three heat treatments. The reduction in free surface corrosion resistance of CM is linearly correlated with the number of heat treatments, but this does not hold true for BM. This study provides valuable references for the assessment of performance loss under heat treatment of clad plates.

Study on the effect of condenser configuration of pulsating heat pipes for space applications

In this study, the effect of condenser configuration on the thermal performance of pulsating heat pipes (PHPs) for space applications is experimentally investigated. The thermal performances of a single-condenser PHP and double-condenser PHP are compared under the constraints of the same evaporator and condenser areas. The PHPs are composed of a meandering channel with 30 turns and are made of a stainless-steel tube with the inner and outer diameters of 1.0 and 1.6 mm, respectively. R-134a is used as the working fluid, and the filling ratio is varied from 30 % to 60 %. Under various experimental conditions, the thermal performances of both single- and double-condenser PHPs are examined from two perspectives. First, the thermal resistances of the two PHPs are compared across a range of condenser temperatures from 10 to 30 °C and heat inputs from 0 to 700 W. According to the experimental observations, the double-condenser PHP exhibits a considerable reduction in thermal resistance, up to 55 % compared with the single-condenser PHP, across all the experimental conditions. Second, the operating ranges of the two PHPs are compared. For the single-condenser PHP, either an increase in the filling ratio or a decrease in the condenser temperature results in a narrower range of stable operation, with a maximum allowable heat input of approximately 200 W. On the other hand, the double-condenser PHP is mostly in the stable operating region regardless of the filling ratio or condenser temperature. Consequently, it exhibits an operating range approximately four times wider than that of the single-condenser PHP, indicating a significantly expanded range of stable operation. These improvements in thermal performance can be attributed to having the effects of doubling the number of evaporator-condenser pairs and halving the length between the evaporator and the condenser.

Coupling effects of micro/nano-scale surface modification and electric current application on fouling resistance and heat transfer

The principle of saving energy and converting waste heat into valuable resources is a core concept. Heat exchange systems are significantly compromised by microbial fouling, which impedes heat transfer and increases energy consumption. This study investigated the coupling effects of micro/nano-scale surface modifications and the application of electric currents as a novel approach to inhibit microbial fouling. Smooth copper surface, electrochemical deposition (ECD) surface, and Nickel-Phosphorus-Polytetrafluoroethylene (Ni-P-PTFE) modified surface were tested and compared. Firstly, we analyzed the average heat transfer coefficient under clean conditions, taking into account different surface characteristics. Then, we employed a series of fouling experiments to evaluate the anti-biofouling performance of smooth copper surfaces, ECD surfaces, and Ni-P-PTFE surfaces. The assessment involved flow cytometry, Scanning Electron Microscopy (SEM) and measurements of thermal resistance. Finally, we investigated the effect of external electric current on microbial fouling mitigation. Results show that the ECD surface exhibited an enhanced heat transfer and a poor fouling resistance, while the Ni-P-PTFE surface demonstrated an excellent fouling resistance and a minimal increase in thermal resistance. The application of a low direct current density at 0.51 mA/cm² significantly reduced microbial viability on all surfaces. A higher electric current can further inhibit microbial adhesion and proliferation, enhancing the anti-fouling capability of the surfaces. Compared to surfaces without electric current, the smooth copper surface, ECD, and Ni-P-PTFE surfaces at 5.1 mA/cm² displayed a reduction in thermal resistance by 45.7%, 36.8%, and 38.1%, respectively. At 51 mA/cm², the reduction in thermal resistance for smooth copper surface, ECD, and Ni-P-PTFE surfaces was 75.7%, 78.2%, and 57.1%, respectively. This comprehensive study has validated the potential of combining micro/nano-scale surface modifications with electric current application as an effective strategy for enhancing heat transfer efficiency and anti-fouling properties of heat exchange systems.

The Preparation and Properties of a Ni-SiO2 Superamphiphobic Coating Obtained by Electrodeposition

Superamphiphobic coatings have shown great potential in many fields such as with their anti-corrosion, high-temperature resistance, self-cleaning, and drag reduction properties. However, due to the poor stability of their coatings, it is difficult to apply them on a large scale. In this paper, two kinds of SiO2 particles and nickel were co-deposited on the surface of steel to construct a micro/nano dual-scale structure by composite electrodeposition. The surface of the coating was then fluorinated with the low-surface-energy material 1H,1H,2H,2H-Perfluorodecyltriethoxysilane (AC-FAS) to prepare a Ni-SiO2 superamphiphobic coating. The coating has a water contact angle of 159° and an oil contact angle of 151°. The effect of nanoparticle concentration on the wettability and surface morphology of the coating was systematically studied. Comparative experiments revealed that the optimal micro/nanoparticle concentrations were 8 g/L of 20 nm SiO2 and 2 g/L of 1 μm SiO2. This preparation method greatly improves the corrosion resistance, wear resistance, chemical stability, and high-temperature resistance of the coating.

Mechanisms of surfactant improving water injection huff and puff efficiency in tight reservoir

Water injection huff and puff is an economical and effective method to enhance the recovery of tight oil reservoir, in which the addition of suitable surfactants is critical, but its mechanism needs to be further studied. In this paper, the huff and puff process is divided into replenishment, imbibition and water flooding stages. This study compared and analyzed the effects of various surfactants on interfacial tension, wettability, flow resistance, and oil washing efficiency, using mineralized water as the control group. The relationships between different surfactants and imbibition recovery efficiency, water flooding recovery efficiency, and flooding pressure were investigated. The mechanisms by which surfactants influence the imbibition and flooding processes were also explored. The results show that, the effect of permeability on imbibition and water flooding recovery efficiency in natural cores can be ignored. During the imbibition stage, the maximum recovery efficiency with mineralized water is 18.33 %, while with surfactants it is 21.40 %. In the water flooding stage, the maximum recovery efficiency with mineralized water is 3.89 %. The addition of surfactants significantly increases the water flooding recovery efficiency to 19.82 %. Furthermore, surfactants can reduce the water flooding pressure by approximately 7.00 MPa and increase the total recovery rate by about 5.00 %. The primary mechanisms by which surfactants improve the water injection huff and puff effect include reducing interfacial tension, altering wettability, facilitating crude oil detachment from rock surfaces, and enhancing oil washing efficiency. Reduction of flow resistance, leading to a decrease in the pressure required for flooding. The research results provide a theoretical basis for the practical application of surfactants in water injection huff and puff in tight reservoirs.

Large-scale penetration model tests of bucket foundations of different structural types in clay

Clarifying penetration characteristics and accurately predicting penetration resistance of bucket foundations is crucial to ensure their smooth penetration. This study performed large-scale model tests on nearshore seven-compartment (SC) bucket foundations and novel deep-sea five-connected (FC) bucket foundations to systematically explore the penetration attitude, development of soil plugs, flow rates, bucket-soil interactions, and required suction of these two structures in clay. The good penetrability was identified for the new FC bucket foundation. The development of soil plugs due to bucket wall replacement as well as the mechanism of drag reduction of the inner wall and bucket end were revealed. The experiments demonstrated that the penetration flow rate was almost equal to the volume of bucket body entering the soil and accounted for approximately 95% of the total flow rate. A formula for calculating penetration resistance in clay that considers the effect of suction on the reduction in resistance of the inner wall and bucket end was proposed and validated by field tests. The research results improve the safety of bucket foundation penetration in clay and provide significant guidance for the installation of deep-sea FC bucket foundations.

LaMnO3-Mn3O4 nanocomposite: Synergetic effect towards high electrochemical performance

Metal oxides have been a focus of research for energy storage devices. Herein, xLaMnO3 – (100-x) Mn3O4 (LMO-MO) composites (xwt%: 100, 90, 70, and 50) were prepared via one-pot synthesis to elucidate the synergistic effect of the composite constituents on composite’s electrochemical performance. The X-ray diffraction analysis confirmed the presence of individual compounds in the desired ratio and phase. The X-ray photoelectron spectroscopy confirmed the presence of Mn2+ and Mn3+ oxidation states, indicating the presence of both LaMnO3 (LMO) and Mn3O4 (MO) in the composite. The electrochemical performance of composite electrodes prepared using nickel foam was assessed in 1 and 6 M KOH solutions. High specific capacitance measured via cyclic voltammetry of ∼ 770 Fg−1 at a scan rate of 1 mVs−1 was recorded for the composite of LMO-MO (70 %: 30 %) in 6 M KOH. At the same time, charge-discharge curves revealed a maximum specific capacitance of around 405 Fg−1 for an x =70 % sample at a current density of 0.5 Ag−1. The EIS studies show a reduction in the internal resistance of the composite due to the interconnected structure and reversible faradic process at the interface with a high degree of Coulombic efficiency. A higher overall electrochemical performance of the electrode was recorded in a 6 M KOH electrolyte. The enhanced electrochemical performance of the composite is attributed to efficient charge transfer kinetics through the electrode-electrolyte interface via easy electron hopping pathways between LMO and MO in the composite. These findings suggest that the studied LMO-MO composites could be a potential material for pseudocapacitor energy devices.

Electrical and fluorescence in situ monitoring of tumor microenvironment-based pH-responsive polymer dot coated surface

A boronate-ester structure forming a pH-responsive polymer dot (Plu-PD) coated biosensor between carbonized-sp2 rich dopamine-alginate [PD(Alg)] and boronic acid-grafted Pluronic (BA-Pluronic) was developed for the electrochemical and fluorescence detection of cancer cells. The reduced fluorescence (FL) resulting from fluorescence resonance energy transfer (FRET) mediated by π-π interactions within Plu-PD was successfully reinvigorated through the specific cleavage of the boronate-ester bond, triggered by the acidic conditions prevailing in the cancer microenvironment. The anomalous variations in extracellular pH levels observed in cancer (pH ∼6.8), as opposed to the normal cellular pH range of approximately 7.4, serve as robust indicators for discerning cancer cells from their healthy counterparts. Moreover, the Plu-PD coated surface demonstrated remarkable adaptability in modulating its surface structure, concurrently exhibiting tunable electroconductivity under reduced pH conditions, thereby imparting selective responsiveness to cancer cells. The pH-modulated conductivity change was validated by a reduction in resistance from 211 ± 9.7 kΩ at pH 7.4 to 73.9 ± 9.4 kΩ and 61.5 ± 11.5 kΩ at pH 6.8 and 6.0, respectively. The controllable electrochemical characteristics were corroborated through in vitro treatment of cancer cells (HeLa, B16F10, and SNU-C2A) via LED experiments and wireless output analysis. In contrast, identical treatments yielded a limited response in normal cell line (CHO–K1). Notably, the Plu-PD coated surface can be seamlessly integrated with a wireless system to facilitate real-time monitoring of the sensing performance in the presence of cancer and normal cells, enabling rapid and accurate cancer diagnosis using a smartphone.

Molecular Dynamics Simulation and Experimental Study of the Mechanical and Tribological Properties of GNS-COOH/PEEK/PTFE Composites.

Molecular dynamics (MD) simulations were first employed to achieve the optimal sintering temperature of carboxyl-functionalized graphene (GNS-COOH)-modified polyether ether ketone (PEEK)/polytetrafluoroethylene (PTFE) composites. A model of GNS-COOH/PEEK/PTFE composites was constructed to simulate the effects of different sintering temperatures on the mechanical and tribological properties, as well as their underlying atomic mechanisms. Samples of PTFE composites were prepared and characterized through experimental methods. Results revealed that the sintering temperature significantly affects the intermolecular forces, mechanical properties, and tribological characteristics of the composites. The agglomeration of the PEEK/PTFE composite matrix was effectively mitigated by introducing GNS-COOH. When the sintering temperature was controlled at 360 °C, the compressive strength of GNS-COOH/PEEK/PTFE composites was improved compared to GNS/PEEK/PTFE composites, albeit with a slight reduction in wear resistance. This study provides a theoretical reference for the preparation process and performance evaluation of new materials.

Graphene Oxide-Silica Green Hybrid Nanocomposites: Fabrication via Latex Mixing and Mechanical Properties Evaluation

ABSTRACT This study investigates the incorporation of sustainable self-assembled graphene oxide-nano silica (GO/NS) hybrid nanoparticles into the natural rubber latex matrix via latex mixing. The primary objective is to assess the synergistic impact of these nanofillers on the mechanical properties of natural rubber latex using both static and dynamic mechanical analysis. Results reveal significant enhancements in mechanical properties, with NRL GO/NS 2 exhibiting a remarkable 188% increase in tensile strength and NRL GO/NS 3 showing a substantial 107% increase. Furthermore, NRL GO/NS 3 demonstrates a 30% reduction in rolling resistance and a remarkable 200% improvement in wet grip, while NRL GO/NS 2 exhibits an 88% increase in wet grip and a 43% decrease in rolling resistance, suggesting potential fuel efficiency benefits. These advancements hold promise for various applications such as automotive tire manufacturing, biomedical devices, and the production of elastomeric goods.

The spectrum of systemic sclerosis-associated pulmonary hypertension: Insights from the ASPIRE registry

There are limited data assessing the spectrum of systemic sclerosis-associated pulmonary hypertension (PH). Data for 912 systemic sclerosis patients assessed between 2000and 2020 were retrieved from the Assessing the Spectrum of Pulmonary hypertension Identified at a REferral centre (ASPIRE) registry and classified based on 2022 European Society of Cardiology/European Respiratory Society(ESC/ERS) guidelines and multimodality investigations. Reduction in pulmonary vascular resistance (PVR) diagnostic threshold to >2WU resulted in a 19% increase in precapillary PH diagnoses. Patients with PVR ≤2WU had superior survival to PVR >2-3WU which was similar to PVR >3-4WU. Survival in pulmonary arterial hypertension (PAH) was superior to PH associated with lung disease. However, patients with mild parenchymal disease on CT had similar characteristics and outcomes to patients without lung disease. Combined pre- and postcapillary PH had significantly poorer survival than isolated postcapillary PH. Patients with mean pulmonary arterial wedge pressure (PAWP) 13-15mmHg had similar haemodynamics and left atrial volumes to those with PAWP>15mmHg. Unclassified-PH had more frequently dilated left atria and higher PAWP than PAH. Although Unclassified-PH had a similar survival to No-PH, 36% were subsequently diagnosed with PAH or PH associated with left heart disease. The presence of 2-3 radiological signs of pulmonary veno-occlusive disease was noted in 7% of PAH patients and was associated with worse survival. Improvement in incremental shuttle walking distance of ≥30m following initiation of PAH therapy was associated with superior survival. PAH patients diagnosed after 2011 had greater use of combination therapy and superior survival. A number of systemic sclerosis PH phenotypes can be recognized and characterized using haemodynamics, lung function and multimodality imaging.

Development of a prognostic model for NSCLC based on differential genes in tumour stem cells

Non-small cell lung cancer (NSCLC) constitutes a significant portion of lung cancers and cytotoxic drugs (e.g. cisplatin) are currently the first-line treatment. However, NSCLC has developed resistance to this drug, which limits the therapeutic effect and thus affects prognosis. NSCLC sc-RNA-seq data were downloaded from the GEO database and Ku Leuven Laboratory for Functional Epigenetics, and bulk RNA-seq data were obtained from the TCGA database. The “Seurat” package was employed for scRNA-seq data processing, and the uniform manifold approximation and projection (UMAP) were applied for downscaling and cluster identification. Use the FindAllMarkers function to find differential genes (DEGs) for tumor stem cells. Then, we performed univariate regression analyses on the DEGs to identify potential prognostic genes. We created a machine learning framework based on potential prognostic genes, which combines 10 machine learning methods and their 101 combinations to get the optimal prognostic risk model. The model was evaluated in the training set and validation set. A nomogram was developed to provide physicians with a quantitative tool for prognosis prediction. Finally, we evaluated the expression and functionality of SLC2A1. We discovered 22 cell clusters containing 218379 cells by examining single-cell RNA sequencing datasets (GSE148071, KU_lom, GSE131907, GSE136246, GSE127465). Tumour cells were isolated for subpopulation analysis and 162 differential genes from SOX2_cancer were obtained. After univariate Cox analysis, we found 23 genes with prognostic potential prognostic value and utilized them to develop 101‑combination machine learning computational framework. We eventually picked the best performing ‘StepCox[both] + RSF’, which includes 8 genes. The model has a relatively high prediction accuracy in both TCGA and GEO datasets. In in vitro investigations, targeted suppression of the SLC2A1 gene resulted in significant reductions in proliferation, invasion and migration in A549 cells. In addition, a significant reduction in cisplatin resistance was seen in A549/DDP cells. The outcomes demonstrated the precision and credibility of the prognostic model for NSCLC, highlighting its potential significance in the treatment and prognosis of individuals affected by this disease. SLC2A1 may become a promising prognostic marker and a potential therapeutic target, offering valuable insights to inform clinical treatment decisions.

Unconventional magnetoresistance and resistivity scaling in amorphous CoSi thin films

The resistivity scaling of Cu electrical interconnects represents a critical challenge in Si CMOS technology. As interconnect dimensions reach below 10 nm, Cu resistivity increases significantly due to surface scattering. Topological materials have been considered for application in ultra-scaled interconnects (below 5 nm), due to their topologically protected surface states that have reduced electron scattering. Recent theoretical work on the topological chiral semimetal CoSi suggests that this material could offer lower resistivity than Cu at dimensions smaller than 10 nm. Here we investigate the scaling trend of textured and amorphous CoSi thin films, deposited by molecular beam epitaxy in a thickness range between 2 and 82.5 nm. Contrary to predictions of standard resistivity models, we report here a reduction in resistivity for thin amorphous CoSi films, which is instead consistent with surface-dominated transport. Moreover, magnetotransport measurements reveal significant enhancement of the magnetoresistance in scaled films, highlighting the complex transport mechanisms present in these highly disordered films at thicknesses of a few nanometers.

Pristine NASICON Electrolyte: A High Ionic Conductivity and Enhanced Dendrite Resistance Through Zirconia (ZrO2) Impurity-free Solid-Electrolyte Design.

Sodium batteries are considered a promising candidate for large-scale grid storage at tropical climate zone, and solid-state sodium metal batteries have a strong proposition as high energy density battery. The main challenge is to develop ultra-pure solid-state ceramic electrolyte and compatible metal interface. Here, a scalable and energy-efficient synthesis strategy of sodium (Na) Super Ionic CONductor, Na1+xZr2SixP3-xO12(x = 2, NZSP) solid electrolyte, has been introduced with the complete removal of unreacted zirconium oxide (ZrO2) impurities. Additionally, the reaction mechanism for the formation of pure phase NZSP is reported for the first time. The NZSP prepared by utilizing the Zr precursor, i.e., tetragonal zirconium oxide (t-ZrO2) derived from the Zr(OH)4 gets quickly and completely consumed in the synthesis process leaving no unreacted monoclinic ZrO2 impurities. The synthesis process only needs a minimum stay of 4 h, which is three times less than the conventional synthesis method. The elimination of ZrO2 impurities results in a 2.5-fold reduction in grain boundary resistivity, showcasing a total ionic conductivity of 1.75 mS cm-1 at room temperature and a relative density of 98%. The prepared electrolyte demonstrates remarkable resistance to dendrite formation, as evidenced by a high critical current density value of 1.4mA cm-2.

Enhancement in power factor through rare-earth samarium doping in Cu2SnSe3 system

Cu2SnSe3 has drawn enough attention as a potential thermoelectric material due to its unique electronic and thermal properties. We present the impact of Sm doping on the Cu2SnSe3 system’s Sn site. The polycrystalline samples of Cu2Sn1-x Sm x Se3 (0 ≤ x ≤ 0.08) were prepared using the solid-state reaction technique followed by conventional sintering. The crystal structure was characterized using XRD and the results reveal that the samples have a diamond cubic structure with a space group of F4̄3m. Scanning Electron Microscopy (SEM) analysis indicates a uniform surface homogeneity within the sample. Furthermore, the introduction of Sm causes a reduction in porosity. The electrical transport characteristics were studied in the mid temperature range of 300–650 K. The Seebeck coefficient of all the samples were found to be positive within the temperature range under study, suggesting that holes constitute the majority charge carriers. This is also confirmed by the Hall measurements as the carrier concentration was positive for all the samples. The inclusion of Sm has led to a reduction of electrical resistivity and Seebeck coefficient and hence power factor of ~539 μW mK−2 for x = 0.08 at 630 K which is ten times greater as compared to x = 0 whose power factor is ~56 μW mK−2 at 630 K is achieved which makes it suitable for thermoelectric applications.

Comprehensive analysis of the performance of a microfluidic photoelectrochemical solar cell with heat exchanger

A dye-sensitized solar cell (DSSC) is a type of photoelectrochemical cell that converts sunlight directly into electricity using a photoanode with a dye-sensitized, nonporous semiconductor layer. This study investigates the impact of integrating microfluidic capabilities into DSSCs, resulting in a flow-cell configuration that introduces new electrical characteristics without compromising its performance. The primary goal of the work was to define and determine the values of heat, mass, and charge transport resistances, and to explore their relationships with the cell’s current–voltage characteristics, temperature, light intensity, and spectra. We employed both experimental methods and computational fluid dynamics using the Lattice-Boltzmann solver to analyze the cell’s dynamics. A novel multilayered microfluidic DSSC (µDSSC) was designed, featuring an innovative “gapless” configuration with a photoactive surface area exceeding 7 cm2, integrated directly with a microfluidic heat exchanger. This configuration allowed the µDSSC to achieve a power conversion efficiency (PCE) of at least 6 % under standard test conditions, with a fill factor reaching up to 68 %. By gradually covering the cell surface, the impact of series resistance (Rs) on PCE was minimized, enabling a maximum PCE of 19–22 %. A new integral definition of the fill factor (IFF) was proposed, which accurately describes the performance of cells constrained by ion mass transport resistance. For the gapless µDSSC, the IFF ranged from 58 % to 88 %. Additionally, we introduced a maximum cell efficiency (MCE) parameter to represent the cell’s efficiency at the theoretical limit of Rs = 0, determined to be 20.7 % for the gapless µDSSC. This MCE value is specific to the cell and is independent of the illuminated surface area and incident light intensity. The thermal efficiency of µDSSC cells is generally limited by heat conduction through the multilayer structure, but at practical cell surface temperatures of 50–80 °C, this limitation is 3 to 6 times less significant than the limitation imposed by the maximum solar energy flux reaching the cell surface. The integration of microchannels into the cell led to a 58 % reduction in hydraulic resistance along the main flow direction. While electrolyte flow typically reduces efficiency in wide-gap DSSCs, the gapless configuration minimizes mass transport resistance, ensuring that fluid flow does not adversely affect the performance of gapless µDSSCs.