Preferential Direction Research Articles

Harnessing Fungi Signaling in Living Composites.

Signaling pathways in fungi offer a profound avenue for harnessing cellular communication and have garnered considerable interest in biomaterial engineering. Fungi respond to environmental stimuli through intricate signaling networks involving biochemical and electrical pathways, yet deciphering these mechanisms remains a challenge. In this review, an overview of fungal biology and their signaling pathways is provided, which can be activated in response to external stimuli and direct fungal growth and orientation. By examining the hyphal structure and the pathways involved in fungal signaling, the current state of recording fungal electrophysiological signals as well as the landscape of fungal biomaterials is explored. Innovative applications are highlighted, from sustainable materials to biomonitoring systems, and an outlook on the future of harnessing fungi signaling in living composites is provided.

Arsenic speciation in picromerite K2Mg(SO4)2•6H2O: Electron paramagnetic resonance and synchrotron X-ray absorption spectroscopic characterizations and implications for organic fertilizers

Picromerite K2Mg(SO4)2•6H2O (also known as schoenite, schönite, or sulfate of potash) formed from alkaline lakes by evaporation is an increasingly important chlorine-free fertilizer and has been used to produce other organic fertilizers such as arcanite K2SO4 and boussingaultite (NH4)2Mg(SO4)2•6H2O. Picromerite and boussingaultite, two Tutton’s salts, are also common secondary solid phases in diverse types of mine tailings and play important roles in controlling the mobility and bioavailability of various heavy metal(loid)s, including arsenic. In this study, picromerite crystals containing 64 ppm As have been synthesized at ambient conditions from aqueous solutions by slow evaporation. Arsenic K-edge X-ray absorption near-edge-structure (XANES) and extended X-ray absorption fine structure (EXAFS) data show that the dominant oxidation state is +5 and that As5+ occupies the S site in picromerite. Single-crystal and powder electron paramagnetic resonance (EPR) spectra of gamma-ray-irradiated picromerite reveal three arsenic-associated oxyradicals: AsO42−, AsO32−, and AsO22−. The orientations of the principal 75As hyperfine directions of the AsO32− and AsO22− radicals match the bonding directions of the SO42− groups in the picromerite structure, further supporting substitutions of their respective diamagnetic precursors AsO43- and AsO33- for the sulfate group. These AsO42−, AsO32−, and AsO22− radicals in picromerite are similar but not identical to their counterparts in boussingaultite and gypsum, suggesting that sulfate minerals are capable of sequestrating both arsenate and arsenite, with important implications for understanding the fate and bioavailability of arsenic associated with agricultural applications of organic fertilizers.

Hydrogen-Bonding-Regulated Morphology Control and the Impact on the Antibacterial Activity of Cationic π-Amphiphiles.

This manuscript describes the synthesis, self-assembly, and antibacterial properties of naphthalene-diimide (NDI)-derived cationic π-amphiphiles. Three such asymmetric NDI derivatives with a nonionic hydrophilic wedge and a guanidine group in the two opposite sides of the NDI chromophore were considered. They differ by a single functional group (hydrazide, amide, and ester for NDI-1, NDI-2, and NDI-3, respectively), located in the linker between the NDI and the hydrophilic wedge. For NDI-1, the H-bonding among the hydrazides regulated unilateral stacking and a preferential direction of curvature of the resulting supramolecular polymer, producing an unsymmetric polymersome with the guanidinium groups displayed at the outer surface. NDI-3, lacking any H-bonding group, exhibits π-stacking without any preferential orientation and generates spherical particles with a relatively poor display of the guanidium groups. In sharp contrast to NDI-1, NDI-2 exhibits an entangled one-dimensional (1D) fibrillar morphology, indicating the prominent role of the H-bonding motif of the amide group and flexibility of the linker. The antibacterial activity of these assemblies was probed against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). NDI-1 showed the most promising antibacterial activity with a minimum inhibitory concentration (MIC) of ∼7.8 μg/mL against S. aureus and moderate activity (MIC ∼ 125 μg/mL) against E. coli. In sharp contrast, NDI-3 did not show any significant activity against the bacteria, suggesting a strong impact of the H-bonding-regulated directional assembly. NDI-2, forming a fibrillar network, showed moderate activity against S. aureus and negligible activity against E. coli, highlighting a significant impact of the morphology. All of these three molecules were found to be compatible with mammalian cells from the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT) and hemolysis assay. The mechanistic investigation by membrane polarization assay, live/dead fluorescence assay, and microscopy studies confirmed the membrane disruption mechanism of cell killing for the lead candidate NDI-1.

Enhancing urban livability: Analyzing Tehran through equitable land use distribution

Urban livability, a concept integral to human settlements, lacks a universally agreed-upon definition. It encompasses various aspects influencing the attractiveness and quality of life in a city. The research adopts an objective evaluation method, focusing on equitable access to urban services. The study aims to address these challenges by examining the livability of Tehran's 22 districts, emphasizing access to essential services. Employing a comprehensive methodology, the research utilizes analytical tools such as Standard Deviational Ellipse analysis (SDE), Average Nearest Neighbor (ANN), and the Multi-Attributive Border Approximation area Comparison (MABAC) technique. The spatial distribution analysis of urban land uses in Tehran reveals distinct patterns through Standard Deviational Ellipse analysis. Urban land uses exhibit directional orientations and concentrations, providing valuable insights for urban planning. Average Nearest Neighbor analysis indicates clustered distribution across various land uses, emphasizing the need for targeted interventions. The study ranks Tehran's districts based on livability using MABAC technique. District 21 emerges as the most livable, while District 10 faces challenges in service distribution. The findings highlight disparities and call for focused urban planning to enhance overall livability in Tehran, recognizing the importance of equitable access to urban services for a sustainable and cohesive urban environment.

A Study of Directionality Effects in Three-Beam Coaxial Titanium Wire-Based Laser Metal Deposition.

Coaxial wire-based laser metal deposition is a versatile and efficient additive process that can achieve a high deposition rate in the manufacturing of complex structures. In this paper, a three-beam coaxial wire system is studied, with particular attention given to the effects of the deposition direction and laser beam orientation on the resulting bead geometry symmetry. With the three-beam laser delivery, the laser spot pattern is not always symmetric with respect to the deposition direction. Single titanium beads are deposited in different directions and at varying deposition rates, and the bead profile is quantitatively scored for multiple symmetry measures. Through an analysis of variance, the deposition direction and deposition rate were found to be insignificant with respect to the resulting bead symmetry for the developed measures. The bead symmetry and geometry are important factors in determining if a build is free of critical defects, and in this study, it is shown that the three-beam coaxial wire deposition setup is a directionally independent process.

Photoassisted Water Purification through an Electrochemically Artificially Adjusted p-Cu2O Light Absorption Layer.

The implementation of photoelectrochemical water purification technology can address prevailing environmental challenges that impede the advancement and prosperity of human society. In this study, Cu, which is abundant on Earth, was fabricated using an electrochemical deposition process, in which the preferential orientation direction and carrier concentration of the Cu-based oxide semiconductor were artificially adjusted by carefully controlling the OH- and applied voltage. In particular, Cu2O grown with a sufficient supply of OH- ions exhibited the (111) preferred orientation, and the (200) surface facet was exposed, independently achieving 90% decomposition efficiency in a methyl orange (MO) solution for 100 min. This specialized method minimizes the recombination loss of electron-hole pairs by increasing the charge separation and transport efficiency of the bulk and surface of the Cu2O multifunctional absorption layer. These discoveries and comprehension not only offer valuable perspectives on mitigating self-photocorrosion in Cu2O absorbing layers but also provide a convenient and expeditious method for the mass production of water purification systems that harness unlimited solar energy. These properties enable significant energy saving and promote high-speed independent removal of organic pollutants (i.e., MO reduction) during the water purification process.

Effects of carbonation modification on shear performance of recycled aggregate concrete beams: Test and mechanism analysis

The effective use of recycled aggregates (RAs) in construction significantly contributes to environmental preservation and the conservation of non-renewable natural resources. However, RAs typically exhibit inferior performance relative to natural aggregates (NAs). To improve the quality of RAs, carbonation modification has been introduced as an eco-friendly and practical method. This study explores the shear performance of concrete beams that incorporate various replacement ratios (30 %, 50 %, 70 %, and 100 %) of carbonated recycled aggregates (CRAs). The experiment employed Digital image correlation (DIC) system to evaluate the stress distribution on the concrete surface within the shear span section. The evaluation of shear performance was conducted through comprehensive analysis includes load-deflection curve, steel strain, the width of the primary diagonal crack, average principal tensile strain, orientation of principal directions, average shear strain, and shear deflection. A practical approach was adopted to separate the shear strength contributions of transverse steel (Vs) and concrete (Vc), based on transverse steel strains along the primary diagonal crack. Results indicate that carbonated recycled aggregate concrete (CRAC) beams demonstrate enhanced shear performance in comparison to recycled aggregate concrete beams. Shear strength significantly decreases with replacement rates exceeding 70 %. Furthermore, the experimental results were compared against shear strength with the design codes, and shear deflection with existing models.

Performance improvement of HfO2-based ferroelectric with 3D cylindrical capacitor stress optimization

To meet commercialization requirements, the distributions of materials in hafnium-based ferroelectric devices—including their phase and orientation—need to be controlled. This article presents a method for improving the ferroelectric phase ratio and orientation by adjusting the stress distribution of the annealing structure in a three-dimensional capacitor. In such a structure, stress can be applied in three directions: tangential, axial, and radial; there are, thus, more ways to regulate stress in three-dimensional structures than in two-dimensional structures. This work sought to clarify the role of the stress direction on the proportions and orientations of ferroelectric phases. The results of stress simulations show that a structure with an internal TiN electrode, but no filling provides greater axial and tangential stresses in the hafnium-oxide layer. In comparison with the case of the hole being filled with tungsten, the proportion of the O phase is increased by approximately 20%, and in experiments, the projection of the polarization direction onto the normal was found to be increased by 5%. Axial and tangential stresses are regarded to be beneficial for the formation of the O phase and for improving the orientation of the polarization direction. This work provides a theoretical basis and guidance for the three-dimensional integration of hafnium-based ferroelectric materials.

Joint stereo 3D object detection and implicit surface reconstruction

We present a new learning-based framework S-3D-RCNN that can recover accurate object orientation in SO(3) and simultaneously predict implicit rigid shapes from stereo RGB images. For orientation estimation, in contrast to previous studies that map local appearance to observation angles, we propose a progressive approach by extracting meaningful Intermediate Geometrical Representations (IGRs). This approach features a deep model that transforms perceived intensities from one or two views to object part coordinates to achieve direct egocentric object orientation estimation in the camera coordinate system. To further achieve finer description inside 3D bounding boxes, we investigate the implicit shape estimation problem from stereo images. We model visible object surfaces by designing a point-based representation, augmenting IGRs to explicitly address the unseen surface hallucination problem. Extensive experiments validate the effectiveness of the proposed IGRs, and S-3D-RCNN achieves superior 3D scene understanding performance. We also designed new metrics on the KITTI benchmark for our evaluation of implicit shape estimation.

Microscale analysis reveals nature of hydrophobic biopolymers in aragonite bivalve shells with crossed-lamellar architecture

Bivalve shells with crossed-lamellar architecture consist of random orientation of anisotropic crystallographic directions that adds to the optimization of the mechanical properties of shell biominerals. The source of these anisotropic distortions has been attributed to the organic macromolecules in the inorganic unit. However, very little is known about the organic macromolecules in shells with crossed-lamellar architecture because it is believed that the organics in this shell ultrastructure can hardly be characterized owing to its low content, about 1 wt%. Here, the shells of two bivalve species (Callista kingii and Anadara trapezia) with crossed-lamellar architecture, have been studied by microRaman spectroscopy, FTIR, and histochemical analysis. For the first time, organic macromolecules and inorganic components were simultaneously identified. Using spectroscopic techniques (microRaman and FTIR) and a confocal scanning fluorescence microscopy, the results herein demonstrated minor chitin in the studied samples and document structural protein, collagen-like matrix as the major organic component. The SEM observations revealed a morphological biopolymer meshwork composed of a polygonal network. Based on those combined evidence, this study suggests that the interactions between polysaccharide-based biomolecules and collagen-like matrix are crucial for the mechanical properties of crossed-lamellar layers in bivalve shells. This study highlights the importance of using in-situ approaches for these types of biomaterials and provides another source of biomaterials.

Integrated Analysis by Geophysical and Spatial Data to Identify the Formation of Kepuhlegundi Hot Spring on Bawean Island

Bawean Island is a~result of volcanic activity in the back-arc volcanism zone located on the north side of Java Island. Bawean Island was formed due to the geological structure being controlled by the Paleogene-Neogene tectonic line in the Meratus Pattern. The mantle tearing resulted in the formation of the Bawean Arc. The Kepuhlegundi Hot Spring is a~component of the volcanism product on Bawean Island. To analyze the formation of hot springs in more detail, we conducted magnetic method measurements and integrated the data with gravity satellite and Fault Fracture Density (FFD) methods. The three methods were used to determine the continuity of the mapped geological structures surrounding the hot springs. The FFD method can be used to map the weak zone of the hot spring, which is caused by the lineament surrounding it. The magnetic and gravity methods reveal anomalous contrasts that extend towards the hot springs in the direction of the structure. The magnetic and gravity methods reveal anomalous contrasts that extend towards the hot springs in the direction of the structure. Based on regional anomaly analysis, spectrum analysis indicates that the structure is located at a~shallow depth of 15 to 80 meters. The drawing in each method shows a~dominant orientation in the Northeast-Southwest direction, which corresponds to the orientation of the Meratus Structure Pattern. Kepuhlegundi Hot Spring is formed due to the control of geological structures, allowing hot fluids to flow through fractures as an aquifer.

Swin-Roleaf: A new method for characterizing leaf azimuth angle in large-scale maize plants

Maize is the most productive grain crop in the world in terms of total production and yield. Leaf azimuth angle, the directional orientation of the maize leaf, is an important characteristic that affects the efficiency of sunlight reception and photosynthesis in maize canopies. To study maize plant architecture, most of the previous studies have been focusing on leaf vertical angle characterization due to the inherent difficulty of measuring leaf azimuth angle accurately. Achieving accurate and efficient measurement of leaf azimuth angle in maize is important for yield improvement. Traditionally, leaf azimuth angle is measured manually using a protractor or manual annotations of images, which is time-consuming, costly, and prone to human error. Recent advances in Unmanned Aerial Vehicle (UAV) and artificial intelligence have shown great potential in leaf azimuth angle detection. However, most of the deep learning algorithms for object detection are developed for Horizontal Bounding Boxes (HBBs). To measure the azimuth angle of maize leaves, a robust Oriented Bounding Boxes (OBBs) detection algorithm is needed. In this study, a dataset containing top-view images of maize plants was collected using an UAV. An automated tool, Swin-Roleaf, was developed for maize leaf detection. It is an improvement of the YOLOv5 model, uniquely integrating the Swin Transformer (ST) and Circular Smooth Label (CSL). Swin-Roleaf was able to accurately detect OBBs of individual leaves and thereby enable the estimation of leaf azimuth angle. The experimental results showed that Swin-Roleaf was able to accurately detect maize leaves and measure the azimuth angle with a model OBBAP50 of 90.59% on OBBs. The system-derived leaf azimuth angle was highly correlated with the ground truth with a correlation coefficient larger than 0.96. Our study demonstrates for the first time the feasibility of using UAVs coupled with deep learning algorithms to detect leaf azimuth angles under field conditions. The system can significantly speed up the measurement of maize leaf azimuth angles and provide a new tool to accelerate breeding programs.

Effects of CuCr1Zr contamination on the tensile properties and microstructure of stainless steel 316L produced via laser powder bed fusion

AbstractCopper contamination has a negative effect on the tensile properties of certain stainless steel grades due to a weakening of grain boundaries via liquid metal embrittlement. This is especially problematic given current trends in laser powder bed fusion (L-PBF) that elevate contamination risks, such as multi-material processing or the use of recycled materials. As such, it is critical to establish composition limits for use in standard specifications. This study investigates the changes in tensile properties and cracking behavior in stainless steel alloy 316L contaminated with copper alloy CuCr1Zr at concentrations of 0–10 particle percent (pt.%) in horizontal, diagonal, and vertical build orientations. It is found that microcracks are already present at 1 pt.% Cu alloy and increase in density with contamination. The cracks are generally vertically oriented along columnar grain boundaries and are associated with high local Cu content, thus exacerbating the anisotropy of the as-built material. The contamination decreases the elastic modulus, yield strength (YS), ultimate tensile strength (UTS), and uniform elongation, eventually transitioning from ductile to brittle fracture modes. The build orientation relative to the tensile loading axis is shown to be a critical design parameter due to the preferential crack initiation and growth direction. The fracture surfaces at 10 pt.% contamination show regularly spaced, smooth brick-like cleavage patterns that correspond to the columnar grain dimensions. Even so, the measured YS and UTS exceeded the ASTM F3184-16 standard for CuCr1Zr contaminations up to 5 pt.%. As a conservative limit, it is proposed that a maximum content of 1 wt% Cu be specified for L-PBF SS316L.

Impact of Propagation Environment on the Performance of Direction Oriented Forwarding through Minimum Number of Edge Nodes (DOF-MEN) Routing Protocol In Ad Hoc Networks

One sort of wireless ad-hoc network is called MANET (Mobile Ad-hoc Network), which is an autonomous network made up of wireless nodes and routers connected by wireless connections. Transmission of data in effective way is important. The DOF-MEN (Direction Oriented Forwarding through Minimum Number of Edge Nodes) protocol is the protocol which lessens the amount of messages for route discovery. It attempts to choose just single node as the next following hop. The node's address is added by the sender. Therefore, only the chosen node will receive and subsequently transmit the data. This protocol increases the throughput, Packet Delivery Ratio, and cuts down on the Routing Overhead. Several aspects affect the routing protocol's execution accuracy in mobile ad hoc networks (MANET). The propagation model is a crucial thing to be considered among many. MANET experiences an enormous loss in performance due to blockage between transmission devices and fluctuation in the receiver's signal intensity. Therefore, it's crucial to determine how Radio Propagation Model and study of performance of routing protocol in MANET. Here we do simulation and analysis using NS2 (Network Simulator 2). The outcome demonstrates that the MANET routing protocol's performance is more influenced by the propagation model.

Effect of growth temperature on properties of β-Ga2O3 films grown on AlN by low-pressure chemical vapor deposition

In this work, thin films of β-Ga2O3 were prepared on AlN substrates using low-pressure chemical vapor deposition (LPCVD). The effects of growth temperature on the crystal structure, surface morphology, chemical composition, and photoluminescence properties of the synthesized β-Ga2O3 thin films were then systematically investigated. The results indicated that various films grown at different temperatures in the range of 550–850 °C had a preferred growth orientation in the planar direction (−201). The surface roughness was seen to reduce gradually as the growth temperature was raised. However, excessive temperature (850 °C) led to a reduction in the densification of the prepared films. The surface chemistry of the films was analyzed using X-ray photoelectron spectroscopy (XPS) and the O/Ga ratio of the optimal film was calculated to be 1.49, which is quite close to the optimal stoichiometric ratio of 1.5. Multiple luminescence bands were obtained in the photoluminescence spectra of the films taken at room temperature, where the blue emission formed the dominant bands. The results of the study suggest that the growth temperature has a significant impact on the film properties and that appropriately increasing the growth temperature leads to substantial improvement in the overall quality of the β-Ga2O3 thin films.

Polarized Light from Massive Protoclusters (POLIMAP). I. Dissecting the Role of Magnetic Fields in the Massive Infrared Dark Cloud G28.37+0.07

Magnetic fields may play a crucial role in setting the initial conditions of massive star and star cluster formation. To investigate this, we report SOFIA-HAWC+ 214 μm observations of polarized thermal dust emission and high-resolution GBT-Argus C18O(1-0) observations toward the massive Infrared Dark Cloud (IRDC) G28.37+0.07. Considering the local dispersion of B-field orientations, we produce a map of the B-field strength of the IRDC, which exhibits values between ∼0.03 and 1 mG based on a refined Davis–Chandrasekhar–Fermi method proposed by Skalidis & Tassis. Comparing to a map of inferred density, the IRDC exhibits a B–n relation with a power-law index of 0.51 ± 0.02, which is consistent with a scenario of magnetically regulated anisotropic collapse. Consideration of the mass-to-flux ratio map indicates that magnetic fields are dynamically important in most regions of the IRDC. A virial analysis of a sample of massive, dense cores in the IRDC, including evaluation of magnetic and kinetic internal and surface terms, indicates consistency with virial equilibrium, sub-Alfvénic conditions, and a dominant role for B-fields in regulating collapse. A clear alignment of magnetic field morphology with the direction of the steepest column density gradient is also detected. However, there is no preferred orientation of protostellar outflow directions with the B-field. Overall, these results indicate that magnetic fields play a crucial role in regulating massive star and star cluster formation, and therefore they need to be accounted for in theoretical models of these processes.

Effect of annealing temperature on physical properties and photoelectrochemical behavior of electrodeposited nanostructured NiO thin films for optoelectronic applications

Our paper used a low-cost electrodeposition technique to grow Nickel Oxide (NiO) thin films on fluorine-doped tin oxide (FTO) substrate. As-deposited films were annealed at different temperatures (350, 400, 450, and 500 °C). X-ray diffraction (XRD), Raman spectroscopy (RAM), scanning electron microscopy (SEM), UV–vis spectrophotometer, photoluminescence (PL), Cyclic voltammetry (CV), photocurrent (PC), electrochemical impedance spectroscopy (EIS), and Mott-Schottky analysis (MS) were used to study and investigate the effect of annealing temperatures on the structural, morphological, electrical, and optical properties of prepared thin films. XRD patterns proved the cubic phase of all NiO samples with the preferential orientation in (111) direction. SEM results showed that the grain size increased with increasing annealing temperature. The optical transmission was studied by a UV–vis spectrophotometer, where high transmittance for NiO thin films was found to vary in the range of 73–84 % in the visible wavelength region, depending on the annealing temperatures. At the same time, UV–visible measurements indicate an absorption band edge at 311 nm, mainly recognized as a characteristic direct band gap for prepared NiO. The optical gap calculated from the Tauc relation showed a decreasing trend from 3.97 to 3.86 eV with increasing annealing temperature from 300 °C to 500 °C. PL spectra of synthesized samples revealed two distinct emission peaks at around 400 nm and 490 nm. RAM analysis confirmed the presence of three characteristic peaks related to the vibration of Ni–O bonds. The NiO film annealed at 500 °C displays the highest specific capacitance value by CV analysis. The P-type conductivity of manufactured arrays and enhanced electrical properties were confirmed by PC, EIS, and MS analysis. The highest carrier concentration values (9.19 × 1018 cm−3) and flat band potential (0.82 V) were obtained for samples annealed at 500 °C. Our outcomes proved that NiO-500 °C thin films are ideal candidates for optoelectronic applications.

Microstructural evolution in 12% Cr heat-resistant steel during compression deformation at 650°C

ABSTRACT The 12% Cr heat-resistant steel used for critical components of fossil-fired power plants works in high-temperature and high-pressure steam environments for a long time and inevitably undergoes a certain amount of plastic deformation during service. This plastic deformation will affect the microstructure and hot ductility of the heat-resistant steel and ultimately influence its service life. Therefore, the effect of hot compression deformation on microstructural evolution at 650°C was investigated in this work. As the amount of hot compression deformation increased, the number of subgrains significantly increased, and their sizes gradually decreased. When the amount of deformation reached 50%, dynamic recrystallization occurred, forming a preferred orientation in the rolling direction. <111> and <001> fiber texture appeared in the microstructure when the deformation amount reached 8%, and the intensity of <111> texture was significantly higher than that of <001> texture. Their intensity values further increased with the increase of the amount of deformation. As the amount of hot compression deformation increased, the deviation angle of the Kurdjumov–Sachs (KS) orientation relationship between M23C6 particles and α-Fe gradually increased. Their KS orientation relationship began to be disrupted at the deformation amount of 6% and was completely destroyed at the deformation amount of 20%. With the amount of deformation increasing up to 50%, there were no micropores at the M23C6/matrix interfaces, and no hot cracking occurred. This was mainly attributed to the occurrence of dynamic recrystallization which alleviated stress concentration at the particles /matrix interfaces. The mechanisms of microstructural evolution involving subgrains, grain boundary characteristics, texture evolution, strain distribution, and orientation relationship were discussed in detail.

On quantification of equivalent permeability tensor in sparsely fractured rock masses

The work presented in this paper is focused on the assessment of hydraulic conductivity in sparsely fractured rocks. Different simplified methodologies are used, including Oda's notion of permeability tensor as well as pipe network models, and the results are compared with those generated by a more accurate approach, which incorporates a constitutive law with embedded discontinuity (CLED). Several numerical examples involving fluid flow in the presence of discrete fracture networks are provided, and the estimates of principal values as well as eigenvectors of the equivalent conductivity tensor are compared for all methodologies employed. It is demonstrated that the predictions corresponding to pipe-network model, enhanced by the graph theory algorithm, are fairly consistent with CLED approach, particularly in terms of assessing the orientation of principal directions of permeability. A simple pragmatic procedure is therefore suggested for defining the anisotropic equivalent hydraulic conductivity operator.

Anionic chemistry regulation boosting the reversible redox in CoSexTey@C polyhedrons for sodium storage

CoTe2 as a potential electrode material for sodium-ion batteries (SIBs) suffers severe volume expansion and rapid capacity degradation. Herein, we propose an anionic chemistry regulation strategy to enhance the redox performance of CoTe2 by Se substitution which creates more porosity inside the structure to accommodate the volume expansion. Physical characterizations and theoretical calculations have studied the structural and dynamical influence of Se/Te ratio on the overall performance. As a result, CoSe1.33Te0.67@C with a 〈111〉 preferential growth direction exhibited the most balanced performance, which delivered a high initial specific capacity of 795 mAh/g at 0.05 A/g, a high rate performance of 5 A/g and a capacity retention of 370 mAh/g after 400 cycles at 0.5 A/g. Accordingly, a full SIB was constructed with a Na3V2(PO4)3 cathode and a CoSe0.67Te0.33@C anode, delivering a maximum energy density of 197.2 Wh kg−1. These results have proved that anionic chemistry regulation is quite efficient to synthesize metal tellurides with high redox activity and long life-span for SIB.