Homogeneous Behavior Research Articles

In Situ Constructing Robust and Highly Conductive Solid Electrolyte with Tailored Interfacial Chemistry for Durable Li Metal Batteries.

Employing nanofiber framework for in situ polymerized solid-state lithium metal batteries (SSLMBs) is impeded by the insufficient Li+ transport properties and severe dendritic Li growth. Both critical issues originate from the shortage of Li+ conduction highways and nonuniform Li+ flux, as randomly-scattered nanofiber backbone is highly prone to slippage during battery assembly. Herein, a robust fabric of Li0.33La0.56Ce0.06Ti0.94O3-δ/polyacrylonitrile framework (p-LLCTO/PAN) with inbuilt Li+ transport channels and high interfacial Li+ flux is reported to manipulate the critical current density of SSLMBs. Upon the merits of defective LLCTO fillers, TFSI- confinement and linear alignment of Li+ conduction pathways are realized inside 1D p-LLCTO/PAN tunnels, enabling remarkable ionic conductivity of 1.21mScm-1 (26°C) and tLi+ of 0.93 for in situ polymerized polyvinylene carbonate (PVC) electrolyte. Specifically, molecular reinforcement protocol on PAN framework further rearranges the Li+ highway distribution on Li metal and alters Li dendrite nucleation pattern, boosting a homogeneous Li deposition behavior with favorable SEI interface chemistry. Accordingly, excellent capacity retention of 76.7% over 1000 cycles at 2 C for Li||LiFePO4 battery and 76.2% over 500 cycles at 1 C for Li||LiNi0.5Co0.2Mn0.3O2 battery are delivered by p-LLCTO/PAN/PVC electrolyte, presenting feasible route in overcoming the bottleneck of dendrite penetration in in situ polymerized SSLMBs.

Effect of γ forming element additions on the homogenization behavior and formation of hierarchical microstructures in Ni-based superalloys

Here, we study the homogenization behavior and microstructure of seven Ni-Al-Ti alloys with quaternary additions of γ forming elements 4Cr, 4Co, 4Ru, 4Mo, 4Hf, 4 W and 2Re. To design a homogenization treatment, the as-cast microstructure is analyzed revealing the diffusion distances x between dendrite cores and interdendritic regions. The temperatures for homogenization are determined using differential scanning calorimetry (DSC) and Thermo-Calc simulations, to be between 1150 and 1275 °C. The time to achieve homogenization is modelled based on the residual segregation index δ utilizing diffusion distance, homogenization temperature and diffusion data. Electron probe micro analyzer (EPMA) measurements show that our predictions match for the 4Cr, 4Co, 4Ru, 4 W and 2Re alloys while the 4Hf alloy shows insufficient homogenization. Transmission electron microscopy (TEM) reveals a two-phase γ/γ’ microstructure after 750 °C / 24 h, whereby the 4Co and 4Ru alloys form hierarchical microstructures. We observe γ plates in the 4Co alloy and γ spheres in the 4Ru alloy. Ru in the 4Ru alloy is involved in stabilizing the morphology of γ spheres. We provide a straightforward method for the design of homogenization treatments of Ni-based superalloys and demonstrate an alloy design pathway for tailoring the phase stability of hierarchical microstructures.

Meso-scopically homogeneous superelastic transformation and related elastocaloric effect in a textured Ti-based shape memory alloy

Homogeneous superelastic behavior in shape memory alloys (SMAs) has been confirmed to be crucial for functional and structural fatigue properties, and more importantly, for stable elastocaloric effect (eCE). Here, the Ti–22Nb–4Zr–2Ta plate was prepared by successive cold rolling at 98.5%, followed by annealing at 1023 K for 30 min, forming a strong recrystallized texture, denoted as {112}β < 110>β. Such favorable texture contributed to a completely recoverable superelastic strain of ∼2.4% with narrow hysteresis of 35/45 MPa under isothermal/quasi-adiabatic conditions, which resulted in homogeneous martensitic transformation (MT) and adiabatic temperature changes (ΔTadi) of 4.8 K upon loading and 4.4 K upon unloading. The observation on the evolution of space-resolved strain and temperature throughout the sample revealed that the intrinsic feature of diffuse transformation along with favorable texture contributed to meso-scopically homogeneous transformation and related eCE. A standard deviation of strain was determined to be only 0.05%, corresponding to a small temperature deviation of 0.2–0.3 K, which quantitatively demonstrated the homogeneity, potentially high solid-state cooling performance efficiency, and long structural and functional fatigue life in Ti-based SMAs.

Experimental validation on the phase separation for the 2-(Diisopropylamino)ethyl methacrylate and Poly[2-(diisopropylamino)ethyl methacrylate] in supercritical CO2

Using an intense pressure flexible volume apparatus, the phase transition equilibrium of the two-component mixture consisting of 2-(diisopropylamino)ethyl methacrylate (2DIPAEMA) + supercritical carbon dioxide (Sc CO2), as well as poly(2-(diisopropylamino)ethyl methacrylate) [P(2DIPAEMA)] with various co-solvents (propylene, propane, 1-butene, butane, and dimethyl ether), was investigated. Additionally, the three-component system P(2DIPAEMA) + 2DIPAEMA (0.0, 0.0245, 0.0523, 0.1036 mol fraction) + Sc CO2 was studied at a specific temperature range of 313.2 K to 454.5 K and an upper-pressure limit of 171.03 MPa. The dew-point, critical-point, and bubble-point equilibria data for the 2DIPAEMA + Sc CO2 binary system at a temperature interval of 313.2–393.2 K and a pressure limit of 21.61 MPa were measured. At low co-solvent concentrations, the solubility transition curve in the three-component P(2DIPAEMA) + Sc CO2 + co-solvent system (comprising propylene, propane, 1-butene, butane, and dimethyl ether) shows a cloud pressure curve that increases as temperature decreases. However, at higher concentrations, cloud pressure decreased rapidly, but a minor change in cloud pressure with temperature was recorded, indicating a homogeneous single-phase behavior resembling a type-I phase diagram. The van der Waals one-fluid mixing rule was employed to compare the experimentally calculated data with the computed and modelled data of the Peng–Robinson mathematical equation. It was discovered that the computed values were consistent with the experimental values. The RMSD for the (Sc CO2 + 2DIPAEMA) system was 4.37 % at five different temperatures. The critical parameter of the pure component, 2DIPAEMA, was estimated using the Joback-Lyderson approach.

Evaluation on the characteristics of homogeneous catalytic hydrothermal gasification of waste rubber based on ReaxFF-MD simulation

Massive waste tires unrecycled will pose a significant threat to the urban environment. Hydrothermal gasification (HTG) is a promising technology converting polymer wastes into H2-rich syngas. The homogeneous catalytic hydrothermal gasification behavior of natural rubber (NR) and styrene-butadiene rubber (SBR) was estimated based on reactive force field molecular dynamics (ReaxFF-MD). KOH had the highest catalytic performance in enhancing the degradation efficiency (22.5 %) and H2 yield (27.4 %) in HTG of NR, and K2CO3 demonstrated the most optimal alkaline catalyst for SBR to enhance the degradation efficiency (27.2 %) and H2 yield (37.9 %). K2CO3 loading with 6 wt% manifested the optimum amount for lifting DE and H2 yield in HTG of SBR, while 10 wt% K2CO3 loading represented the best effect for lifting DE (26.5 %) and H2 yield (42.6 %) in HTG of NR. The activation energy of SBR in HTG was about 259 kJ/mol, which was about 72 kJ/mol higher than that of NR. With 6 wt% K2CO3, the activation energy of SBR and NR in HTG decreased to about 143 kJ/mol and 122 kJ/mol, respectively. The present work could provide essential theoretical support and fundamental data for the application of the homogeneous catalysts in HTG recycling of waste rubber materials.

Aspects of the production of ornamental stone plates with fragments of hyaline quartz and the potential for color development from irradiation combined with heat treatment

The present work refers to a study on the production of dimension stones slabs with hyaline quartz and its potential for color development through irradiation combined with heat treatment. The research included technical visits to a company that produces slabs (combining parts of sliced quartz crystals) for the dimension stone industry, where the stages of slabs production were described. The material used was classified as a colorless hyaline quartz, with the presence of partially healed fractures and monophasic fluid inclusions, that need more attention when in the heat treatment. The study evaluated the potential for color development through combined irradiation and thermal treatments, using analyses at the Federal University of Espirito Santo - UFES gem and characterization laboratory and at the infrared spectroscopy laboratory at the Nuclear Technology Development Center - CDTN. The results showed that hyaline quartz fragments can develop characteristic colors depending on the irradiation dose and heat treatment. If they have homogeneous behavior in relation to the spectral analysis, the crystals can develop characteristic colors from a weak green gold (yellow-green) to yellow and brown, keeping the proper irradiation doses (yellow-green, 60-100 kGy; yellow, 100- 200kGy and brown &gt;200kGy), but such colors would still have to be submitted for verification of acceptance by the dimension stone market.

Applying magnetic techniques to determine the evolution of reactive diapirs: A case study of the Lusitanian basin

The western Iberian margin underwent complex evolution during the Mesozoic and Cenozoic. It was subjected to successive extensional and compressional phases, where salt tectonics played a significant role in both. The role of onshore structures during basin formation and inversion is not fully understood, and different chronological relationships between structures have been proposed. To better understand the history of salt body emplacement, we present paleomagnetic and magnetic fabric data from Jurassic carbonates, comprising cover rocks of the diapiric system. Magnetic fabrics show two types of behavior. Type 1 fabrics show magnetic foliation parallel to bedding—the magnetic lineation, after bedding correction, is horizontal and parallel to the diapiric contacts. This fabric is a consequence of overpressure during salt migration, whose effect is limited to the area near the diapirs. Type 2 fabric is characterized by a magnetic lineation parallel to the strike of bedding and—the intermediate and minimum magnetic axes are dispersed on a vertical girdle parallel to the shortening direction. This is interpreted as a compressional fabric that developed during basin inversion. Paleomagnetic results reveal a stable paleomagnetic component carry by magnetite with characteristic unblocking temperatures (175–450 °C) and coercivities (30–100 mT). Twelve of the 14 calculated mean directions show homogeneous behavior in their magnetic properties and directions, with positive inclinations, northward directions, with synfolding to postfolding behavior. We calculated the remagnetization direction (Dec: 347.5°, Inc.: 51.3°) and compare it to the APWP. It was likely acquired during the Cretaceous Normal Superchron, following the extensional deformation phase and prior to basin inversion. The paleodips (i.e., the bedding at remagnetization times) indicate that tilting occurred mainly during the extensional stage, meaning that the diapirs had already been developed. This indicates a strong Mesozoic salt tectonic component in the present-day structuring of this sector of the Lusitanian basin.

Homogeneity, metallurgical, mechanical, wear, and corrosion behavior of Ni and B4C coatings deposited on 304 stainless steels developed by microwave cladding technique

The microwave cladding technique for depositing Ni and 10 % B4C coatings on 304 stainless steel has yielded significant advancements in material properties and performance. The key findings of this study revealed remarkable improvements, including a 43.33% increase in material hardness, indicating enhanced wear resistance and mechanical properties. This improvement was attributed to the uniform distribution of B4C and Ni on the cladding surface, ensuring a consistent interfacial layer developed between SS 304 and the cladding surface without cracks and porosity. Microstructural analysis at 500× magnification unveiled an impressive 2233.35 grains per square inch, showcasing the refined grain structure achieved during the cladding process. Wear testing demonstrated a low wear rate of 0.00308 mm³/m and a favorable coefficient of friction of 0.1981, confirming the material's suitability for applications with demanding frictional conditions. Furthermore, the corrosion behavior of the coated 304 stainless steel was assessed, revealing a minimal corrosion weight loss of only 0.42 mg for the Ni and 10% B4C coated sample. The presence of various carbide phases, such as Cr2C, Cr23C6, Cr7BC4, Fe5C2, and Fe23B6, within the cladding further contributed to the material's enhanced mechanical and wear properties.

Pharmacotechnical aspects of a stable probiotic formulation toward multidrug-resistance antibacterial activity: design and quality control

As a well-known group of the probiotic family, the Lactobacillus has increasingly contributed to hindering the growth of pathogens, particularly resistant species, in the last decades. Since antibiotic resistance has become a severe problem in global healthcare systems and considerably increased the mortality and morbidity rate in infectious diseases, we aimed to obtain a new stable formulation of Lactobacillus to overcome resistant infections. For this purpose, we designed various gel formulations containing Lactobacillus rhamnosus (L. rhamnosus) as an active pharmaceutical ingredient (API) in a water base and oil base gel, evaluated the probiotic stability in formulation to obtain an optimum formulation, and finally, investigated the antibacterial activities of that against two common hospital-associated multidrug-resistant pathogens, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). Furthermore, the pharmaceutical aspects of the optimum formulation, including stability, homogeneity, spreadability, pH value, conductivity, and rheological behavior, were assessed.The results indicated that the optimum formulation based on glycerol exhibited desirable pharmaceutical properties, including long-term stability, a perfect level of homogeneity, an acceptable range of spreadability with pseudo-plastic thixotropic behavior, and a promising antibacterial potential against MRSA and VRE. Our findings indicate that this novel probiotic formulation could be an excellent candidate to cope with antibiotic-resistant species, representing a hopeful treatment potential for topical applications, particularly in incurable infections. However, further in vivo studies seem warranted to evaluate their bactericidal activity against multi-drug resistant microorganisms.

Stable Harsh-Temperature Lithium Metal Batteries Enabled by Tailoring Solvation Structure in Ether Electrolytes.

For lithium metal batteries (LMBs), the elevated operating temperature results in severe capacity fading and safety issues due to unstable electrode-electrolyte interphases and electrolyte solvation structures. Therefore, it is crucial to construct advanced electrolytes capable of tolerating harsh environments to ensure stable LMBs. Here, we proposed a stable localized high-concentration electrolyte (LHCE) by introducing the highly solvating power solvent diethylene glycol dimethyl ether (DGDME). Computational and experimental evidence discloses that the original DGDME-LHCE shows favorable features for high-temperature LMBs, including high Li+-binding stability, electro-oxidation resistance, thermal stability, and nonflammability. The tailored solvated sheath structure achieves the preferred decomposition of anions, inducing the stable (cathode and Li anode)/interphases simultaneously, which enables a homogeneous Li plating-stripping behavior on the anode side and a high-voltage tolerance on the cathode side. For the Li||Li cells coupled with DGDME-LHCE, they showcase outstanding reversibility (a long lifespan of exceeding 1900 h). We demonstrate exceptional cyclic stability (∼95.59%, 250 cycles), high Coulombic efficiency (>99.88%), and impressive high-voltage (4.5 V) and high-temperature (60 °C) performances in Li||NCM523 cells using DGDME-LHCE. Our advances shed light on an encouraging ether electrolyte tactic for the Li-metal batteries confronted with stringent high-temperature challenges.

Influence of rheology on mixing homogeneity and mechanical behavior of twin-pipe 3D printable concrete

The twin-pipe pumping technology has been developed for the stiffening control of 3D printable concrete, which is achieved by pumping two different mixtures separately and blending these mixtures using a static mixer before extrusion. The combination of the two mixtures undergoes a significant phase transition in the static mixer from liquid to solid due to accelerated hydration. The phase transition, as well as the mechanical performance of hardened elements, is strongly influenced by the mixing homogeneity of the mixtures. In this study, we examine how the rheological behavior of the two mixtures being combined in the static mixer affects the mixing homogeneity. The rheological behavior was studied by performing flow curve measurements using a dynamic shear rheometer. To characterize the mixing homogeneity, polished cross-sections of 3D-printed elements were prepared and characterized using an innovative macropixel-based image analysis procedure. Specifically, the image analysis-based procedure involves identifying the two mixtures by applying color segmentation, followed by the Poole index method to assess the mixing homogeneity. The results indicate that a low yield stress, especially for the main constituent mixture of which the flow rate is higher than the second constituent mixture, is advantageous to achieve a higher mixing homogeneity. The viscosity or the viscosity ratio of the two constituent mixtures is found to have a minor influence on the mixing homogeneity.

Evaluation of error components in rainfall retrieval from collocated commercial microwave links

Abstract. Opportunistic rainfall sensing using commercial microwave links (CMLs) operating in telecommunication networks has the potential to complement conventional rainfall monitoring; however, the diversity of sensors and their errors are difficult to handle. This analysis empirically evaluates errors in CML observations that manifest discrepancies between collocated sensors without reference to rainfall measurements. Collocated CMLs are evaluated as independent rainfall sensors and enable us to assess the effect of hardware homogeneity and measurement consistency using CML observations at 12 sites within a real telecommunication network in Prague. The evaluation considers 33 rainfall events distinguishing between stratiform and convective rainfall types in the period of 2014–2016, monitored at 1 min temporal resolution. Collocated CMLs of identical and different frequencies are evaluated, and different rainfall types are discussed. The collocated CMLs are in excellent agreement. The inherent error in rain-induced attenuation for paired independent CMLs is 0.4 dB. The high correlation of the rainfall intensity measurements between the collocated sensors was obtained in a range of 0.96 to 0.99, and the root mean square error ranges from 0.4 to 1.7 mm h−1. This confirms the homogeneous behaviour of the hardware in a real network. Therefore, the data of CMLs of the same characteristics can be processed with identical parameters for rainfall retrieval models.

Boosting Zn Anode Utilization by Trace Iodine Ions in Organic‐Water Hybrid Electrolytes through Formation of Anion‐rich Adsorbing Layers

AbstractAqueous Zn batteries are attracting extensive attentions, but their application is still hindered by H2O‐induced Zn‐corrosion and hydrogen evolution reactions. Addition of organic solvents into aqueous electrolytes to limit the H2O activity is a promising solution, but at the cost of greatly reduced Zn anode kinetics. Here we propose a simple strategy for this challenge by adding 50 mM iodine ions into an organic‐water (1,2‐dimethoxyethane (DME)+water) hybrid electrolyte, which enables the electrolyte simultaneously owns the advantages of low H2O activity and accelerated Zn kinetics. We demonstrate that the DME breaks the H2O hydrogen‐bond network and exclude H2O from Zn2+ solvation shell. And the I− is firmly adsorbed on the Zn anode, reducing the Zn2+ de‐solvation barrier from 74.33 kJ mol−1 to 32.26 kJ mol−1 and inducing homogeneous nucleation behavior. With such electrolyte, the Zn//Zn symmetric cell exhibits a record high cycling lifetime (14.5 months) and achieves high Zn anode utilization (75.5 %). In particular, the Zn//VS2@SS full cell with the optimized electrolyte stably cycles for 170 cycles at a low N : P ratio (3.64). Even with the cathode mass‐loading of 16.7 mg cm−2, the full cell maintains the areal capacity of 0.96 mAh cm−2 after 1600 cycles.

An efficient detailed layer model for prediction of separator damage in a Li-Ion pouch cell exposed to transverse compression

Li-ion pouch cells can be understood as thin-layer laminates. Pressure loads normal to flat electrodes can cause failure or thermal runaway. However, detailed models for investigating transverse pressure loads in which each layer is resolved are computationally intensive. This paper outlines two approaches for time-efficient yet accurate detailed explicit finite element models of a cell. Both approaches are characterised by the fact that they are divided into in-plane and out-of-plane behaviour. The modelling of interlaminar contacts is completely omitted, to prevent parasitic contact compliance and efforts for contact handling. A discrete element formulation is used for a computationally efficient simulation of transverse loads. This prevents a reduction of the critical time step, which can result from transversal deformations. The difference between the two modelling approaches lies in the modelling of the out-of-plane behaviour. In the first approach, the behaviour in the out-of-plane direction is generated by characterising each component separately. The second approach assumes homogenous behaviour in the thickness direction. Both approaches rely on characterization data derived from component and cell tests. The cell models are validated against cell tests. Numerical results obtained with the two modelling approaches differ only slightly from the validation data.

Mechanistic insight into homogeneous catalytic crosslinking behavior between cellulose and epoxide by explicit solvent models

Inspired by recent advances on functional modification of cellulosic materials, the crosslinking behaviors of epoxide with cellulose under the catalysis of different homogeneous catalysts including H2O, Brønsted acid, Brønsted base, Lewis acid and neutral salt were systematically investigated using density functional theory (DFT) methods with hybrid micro-solvation-continuum approach. The results showed that catalytic activity, reaction mechanism and regioselectivity are determined by the combined effect of catalyst type, electronic effect and steric hindrance. All the homogeneous catalysts have catalytic activity for the crosslinking reaction, which decreases in the order of NaOH > HCl > NCl3 > MCl2 > CH3COOH > NaCl (N = Fe3+, Al3+; M = Zn2+, Ca2+). Upon the catalysis of NaOH, hydroxyl group of cellulose is firstly deprotonated to form a carbanion-like intermediate which will further attack the less sterically hindered C atom of epoxide showing excellent regioselectivity. Acidic catalysts readily cause epoxide protonated, which suffers from nucleophilic attack of cellulose and forms the carbocation-like intermediate. Brønsted acid exhibits poor regioselectivity, however, Lewis acid shows an interesting balance between catalytic activity and regioselectivity for the crosslinking reaction, which may be attributed to the unique catalysis and stabilization effects of its coordinated H2O on the transition state structure.

A multi-way analysis of similarity patterns in longevity improvements

With the increasing availability of temporal data, a researcher often analyzes information saved into matrices, in which entries are replicated in different occasions. Such multidimensional data can be stored in arrays or tensors in a way that relevant patterns among variables can be teased apart by retaining the time-varying nature of the data. In this work, we show how the nonnegative three-way DEcomposition into DIrectional COMponents (DEDICOM) model is able to extract meaningful relational patterns from multi-population mortality data. The dataset considered is provided by the human mortality database (HMD) and refers to three dimensions: countries, age groups and years. The three-dimensional decomposition technique identifies persistent groups of countries with homogeneous mortality behaviours related to the evolutionary process of longevity improvements. Moreover, we exploit both country group information and recurrent neural networks to forecast future trajectories of similarities among countries’ mortality. Our work, by specifically describing the mesoscale interactions between countries and their evolution in time, could help to design appropriate actions against longevity risk that may impact the stability conditions of life assurance and pensions.

Quantification of inhomogeneity and anisotropy of bituminous mixtures using biaxial experimental data

Most of the existing mechanical characterization test methods and the analytical models for bituminous mixtures are developed based on the assumption of homogenous and isotropic material properties. However, the extent to which such assumptions hold good for bituminous mixtures is not very clear. A biaxial testing scheme in indirect tension mode can come in handy to collect the experimental data at different test temperature regimes. In this study, a bituminous mixture with a nominal maximum aggregate size (NMAS) of 13.2 mm is used to fabricate cylindrical test specimens with 150 mm diameter and 63.5 mm thickness for conducting the repeated load indirect tension (IDT) test. The input load level is selected as 5 to 13 % of the indirect tensile (ITS) failure load in the form of a haversine pulse of 0.1 s loading and 0.9 s rest period. Such loading is applied on zero-degree and ninety-degree orientations of the specimen. The resulting deformations in different directions are measured using linear variable differential transducers (LVDT) attached to both diametral faces of the specimen. The response of the bituminous mixture specimen is captured at three different temperatures of 20, 25, and 30 °C using two different gauge length (half and quarter gauge of the total diameter). A new framework is introduced in this study to evaluate the extent of inhomogeneity and anisotropy of bituminous mixtures. The deformation response of the test specimen captured in the same orientation at different diametral faces is compared to evaluate the extent of inhomogeneity. The extent of anisotropy is evaluated by comparing the deformation response of the test specimen captured at different orientations within the same diametral face. A 15 % variation in the average peak deformation is chosen as the demarcation for determining the extent of inhomogeneity and anisotropy. From this investigation, it is observed that half gauge length experimental data exhibits homogenous and isotropic behavior for all three test temperatures. The quarter gauge length data exhibit similar behavior at 30 °C, whereas it is observed as homogenous and anisotropic at the other two test temperatures.

Behavioural responses to horizontal vibrations of quasi-2D ideal granular beds: an experimental approach

In this experimental study, granular bed response to horizontal vibrations of various frequencies and amplitudes are examined with high-speed imaging. Ideal granular beds consisting of spherical glass beads are horizontally vibrated in a quasi-two-dimensional arrangement, firstly with homogeneous granular media and then with a ternary mixture to explore how bed response deviates with changes to material composition. Phenomena of note are the tendency for the homogeneous material to subdivide into discrete areas of crystalline lattice structures, bounded by non-crystalline lines of bead contacts, labelled in this paper as ‘shear lines’. Shear line failure arises as neighbouring crystalline areas slide relative to one another along their shared non-crystalline border, combining to form one larger crystalline area. Under vibration conditions where particle agitation and relative movement is high, sloshing occurs in the upper bed and triangular granular-gas regions form in the top corners. The ternary mixture also exhibits sloshing at low frequency and large amplitude, but the inhomogeneity of its composition prevents formation of ordered crystalline regions and shear lines, instead promoting low percolation and a jamming effect underneath the sloshing region. Surprisingly strong convective responses are induced in the inhomogeneous bed with more energetic vibrations. From the analysis of shear lines in the homogeneous beds, and of convection in the inhomogeneous beds, comparisons between homogeneous and inhomogeneous bed behaviour are drawn. Results are used to discuss how behavioural response of non-cohesive granular material to horizontal vibrations is ultimately tied to, and changes with, the geometric complexity of the internal packing structure. The concept of ‘geometric compatibility’ between constituent particle species in an inhomogeneous granular medium is proposed as an explanation for the low percolation and strong convective response to vibration.Graphical abstract

Multistability and synchronization of discrete maps via memristive coupling

Due to its internal state, the memristive nonlinearity has different dynamic characteristics from the traditional resistive nonlinearity. It has been proved that the memristive nonlinearity used as a nonlinear coupler to connect two dynamical systems has rich multi-stability phenomena and complex synchronous behaviors. However, few reports have extended memristive couplers and dynamical systems from continuous-time domain to discrete-time domain. To this end, this article proposes a simple memristor-coupled Logistic map (MCLM) model by coupling two identical Logistic maps through a memristive coupler. The MCLM model owns two line fixed point sets related to memristor initial condition and their stability distributions are discussed based on three eigenvalues. The chaotic/hyperchaotic attractors with outstanding performance indicators are revealed using numerical methods, and the initial-related heterogeneous multistability and memristor initial-boosting homogeneous multistability are demonstrated by basins of attraction that have complex and fractal evolutions. Afterwards, by inspecting the synchronous behaviors of the two Logistic maps in the MCLM model, the lag and complete synchronization behaviors dependent on the coupling strength and memristor initial condition, especially the homogeneous synchronization behavior boosted by the memristor initial condition, are disclosed in succession. In addition, an MCU-based hardware platform is fabricated to experimentally validate the numerical results. Of particular interest, to the best knowledge of the authors, the initial-boosting synchronization has not been reported in the literature.

Exploring the joint impacts of income, car ownership, and built environment on daily activity patterns: a cluster analysis of trip chains

Clustering activity patterns and identifying homogeneous travel behaviour through trip chain sequences offer valuable insight for transportation planners and policymakers in addressing transport equity problems and travel demand management. This study explores how income and car-ownership levels determine mobility patterns and travellers' decisions. Unlike previous studies that investigated the travel mode and destinations separately, we designed a novel, aggregated form considering the trip purpose and associated transport mode use as a unit of our analysis. To mitigate the subjectivity of rule-based approaches for trip chain analysis, we employ a novel sequence clustering framework to extract homogeneous clusters of activity patterns. Our results reveal that income and car-ownership levels influence travellers' travel decisions and mobility patterns. Among low-income carless households, 37% of their daily trips include care activities where women more frequently than men play this traditional role in a household by either public transit or a car as a passenger. In the low-income car-owner subsample, females still use public transit for their work trips, whereas males more often use the available car to commute to work. Males of wealthy carless households integrate public transit and active transportation for their daily trips when they live in high-density and more accessible neighbourhoods. While our findings demonstrate the impact of car ownership, income, and built environment on trip-chaining behaviour, we recognise that achieving transport equity will require tailored transportation and land use policies and investments that address the specific needs and barriers faced by different household types, particularly the most vulnerable ones in terms of sociodemographic characteristics, accessibility levels, and affordability issues. Hence, we recommend that policymakers and planners take a more holistic approach to transportation planning that considers the interplay of these factors to ensure that transportation systems and services are accessible, affordable, and equitable for all.