One-dimensional Configuration Research Articles

Magnetite Nanoparticle Assemblies and Their Biological Applications: A Review.

Magnetite nanoparticles (Fe3O4 NPs) have garnered significant attention over the past twenty years, primarily due to their superparamagnetic properties. These properties allow the NPs to respond to external magnetic fields, making them particularly useful in various technological applications. One of the most fascinating aspects of Fe3O4 NPs is their ability to self-assemble into complex structures. Research over this period has focused heavily on how these nanoparticles can be organized into a variety of superstructures, classified by their dimensionality-namely one-dimensional (1D), two-dimensional (2D), and three-dimensional (3D) configurations. Despite a wealth of studies, the literature lacks a systematic review that synthesizes these findings. This review aims to fill that gap by providing a thorough overview of the recent progress made in the fabrication and organization of Fe3O4 NP assemblies via a bottom-up self-assembly approach. This methodology enables the controlled construction of assemblies at the nanoscale, which can lead to distinctive functionalities compared to their individual counterparts. Furthermore, the review explores the diverse applications stemming from these nanoparticle assemblies, particularly emphasizing their contributions to important areas such as imaging, drug delivery, and the diagnosis and treatment of cancer.

Highly efficient preparation of crystalline yttrium carbonate in sodium carbonate system: Formation and growth mechanism

The recovery of rare earths from industrial rare earth leaching solution is typically achieved through the ammonium carbonate precipitation method, which presents challenges in terms of prolonged production cycle and ammonia nitrogen pollution. The present study explored the synthesis of crystalline yttrium carbonate in a sodium carbonate system, employing a conventional mother liquor derived from yttrium chloride. The growth of yttrium carbonate was explored through the lens of density functional theory (DFT) calculations, unveiling a novel perspective on its formation mechanism. The synthesized yttrium carbonate demonstrates enhanced crystallinity, with a D50 value of 19.75 μm achieved under reaction conditions comprising a temperature of 60 °C, stirring rate of 200 r/min, feeding rate of 4 mL/min, and aging time of 30 h. The molar ratio for precipitation is set at 1.6:1. The morphology of yttrium carbonate undergoes a transition from needle-like structures to sheet-like formations, ultimately culminating in the formation of spherical aggregates. The variation in surface energy among distinct crystal planes and CO32– configurations within crystal cells accounts for this phenomenon. The DFT calculations unveil a progression of growth and transformation in yttrium carbonate, commencing from a one-dimensional configuration and culminating in a multidimensional morphology.

A high-rate, impact-driven biaxial fragmentation experiment for ductile materials

The experimental investigation of high strain rate fragmentation has generally been limited to one of two cases: analytically powerful but simple one-dimensional loading configurations, or complicated multiaxial experiments more closely approximating use applications. The former, exemplified by Mott-style ring fragmentation, promotes simple and confident analysis—forming the backbone of the field and revealing the basic nature of dynamic fragmentation in solids—but ignores some critical mechanisms in order to achieve that simplicity. The latter, while informing applications of interest such as ballistic impact, may provide limited insight and is often difficult to access diagnostically. This work presents an attempt to help bridge the gap between 1D ring expansion and 3D fragmentation experiments in the form of impact driven, high-strain-rate biaxial tensile fragmentation experiments. The impact target system consists of a thin specimen plate and a thick polymer impact buffer. The latter serves as a fluid-like medium allowing momentum transfer between an impacting projectile and a rapidly growing near-hemispherical bulge in the specimen plate. The deformation of the specimen and fragmentation pattern are observed using ultra-high-speed optical imaging as well as flash x-ray imaging, and individual fragments are recovered and characterized post-mortem. Using this method, the fragmentation behavior of 6061-T6 Aluminum is investigated at tensile strain rates exceeding 105s−1 and at higher stress triaxiality than that commonly achieved.

Shear Field-Controlled Synthesis of Nitrogen-Doped Carbon Nanochains Forest with High-Density sp3 Defects for Efficient CO2 Electroreduction Reaction.

Defect engineering and nitrogen doping being effective strategies for modulating the surface chemical state of the carbon matrix have been widely explored to promote the catalytic activity in the territory of electrochemical energy storage and conversion devices. However, the controllable synthesis of carbon material with high-density specific defects and high nitrogen doping is still full of challenges. Here, we first synthesize one-dimensional necklace-like nitrogen-doped carbon nanochains (N-CNCs) with abundant defects on carbon fiber paper (CFP) by chemical vapor deposition (CVD) method. The resultant nanostructures are a bunch of interconnected carbon spheres with a hollow structure at the internode and present the complete one-dimensional nanochain configuration. Specifically, the N-CNCs with a corrugated surface possesses high content of sp3 defects (31.2%) and nitrogen (23.6 at %). Combining finite element analysis and experimental results, it reveals that the robust shear field generated by etching gas releasing from thermal decomposition of melamine in situ modulates the CVD process via changing the size and force environment of the metal catalyst droplets for formation of N-CNCs. Benefiting from the high ratio of sp3/sp2 and nitrogen doped on the surface, the N-CNCs@CFP displays a superior electrocatalytic performance for CO2RR, delivering CO Faradaic efficiency of 95.9% and a current density of 23.2 mA cm-2 at -0.86 V vs RHE. This work provides promising synthesis strategy and some inspirations for construction of ultradense and specific defects coupling with nitrogen doping sites into carbon materials to achieve high-efficiency electrocatalysis applications.

A new analytical method for transient heat conduction in composite disks applied to thermal plug and abandonment of oil wells

A new hybrid method for transient heat conduction problems is developed and applied to simulate a Plug and Abandonment (P&A) operation of oil wells. An oil well is approximated by concentric disks in a one-dimensional configuration, which allows for use of polar coordinates. The application of the Separation of Variables Method (SVM) is used as the analytical framework for the solution of the conductive heat transfer arising from a volumetric heat source located in the center of the disks. The SVM is able to solve only time-independent boundary conditions. However, using the Duhamel's theorem, the solution determined with the SVM can be used to achieve the solution when both time-dependent boundary conditions and internal heat generation are prescribed. Lastly, for verification purposes, a commercial software that solves the transient temperature field by means of numerical procedures, providing reliability to the analytical method proposed in this work.

Matrix formulation of the Gaussian expansion of coherent multiple beams in arbitrary dimensions.

Modeling the propagation of beams along laser beamlines is very challenging due to the multidimensional and multiscale configuration of the problem. Spatio-temporal couplings are particularly difficult to address with conventional numerical methods. Here we derive the Wigner function of a sum of Gaussian beams by calculating the multidimensional Fourier transform of the intercorrelation function of the fields. The matrix formulation allows for a simple propagation of the Wigner function in the framework of matrix optics. The relevancy of this approach is assessed by applying this model to one-dimensional and multidimensional configurations and by studying the influence of spatio-temporal couplings when considering propagation and dispersion by a diffraction grating.

Magnetic spirals and biquadratic exchange in 1D MoX[formula omitted] spin chains

We researched the one-dimensional configurations of MoX3 (X = Cl, Br, and I), a spin chain with antiferromagnetically frustrated moments S=32 located at the Mo sites. Our research revealed a spontaneous magnetic order in this group of one-dimensional setups. The magnetic system within the one-dimensional chain reacts collectively due to various magnetic couplings, creating topological spirals with great potential for technology. The key element is the discovery of compelling evidence for biquadratic exchange, which has recently been studied in two-dimensional magnetism. Moreover, we identified antiferromagnetic couplings that go beyond the nearest neighbor, causing frustration. Our research also revealed the connection between these 1D structures through van der Waals interactions, turning them into appealing quasi-two-dimensional magnets with highly tailored electric and magnetic characteristics. Our extensive calculations provide a strong foundation for comprehending the complex behavior of these one-dimensional chains and provide insight into the development of innovative materials with improved electronic and magnetic characteristics. These advances pave the way for various technological applications, especially in new-generation spintronics and magnonic devices.

Experimental and numerical study of PMMA combustion in counterflow configuration

PMMA burning in counterflow has been studied experimentally and numerically. Thermal and chemical structure including concentrations of main species, i.e. ММА, O2, N2, CO2, CO and H2O, as well as an integral parameter (mass loss rate of a sample) were measured. The mathematical model is set in a coupled gas–solid formulation to resolve heat and mass transfer between gas-phase flame and thermally degrading solid combustible. Gas-phase combustion was modeled in the open-source Cantera software in a one-dimensional counterflow flame configuration. Governing equations of solid fuel was solved in an in-house code in two-dimensional formulation. Two chemical mechanisms of MMA oxidation (skeletal and detailed) were employed to resolve gas-phase combustion. Two sets of parameters of PMMA pyrolysis reaction were investigated. Gas phase temperature distribution was experimentally shown to be almost uniform in the direction parallel to the sample's burning surface in the area up to 4 mm from the sample's axis. The best agreement for macroscopic parameter, mass loss rate, was obtained by employing Lengelle pyrolysis kinetics, which is within 10 %. Total heat flux from gas-phase flame to the solid sample is about 23 kW/m2. Both gas-phase combustion mechanisms overpredict maximal temperature in flame by about 200 °C.

High-order adaptive time discretisation of one-dimensional low-Mach reacting flows: A case study of solid propellant combustion

Solving the reactive low-Mach Navier–Stokes equations with high-order adaptive methods in time is still a challenging problem, in particular due to the handling of the algebraic variables involved in the mass constraint. We focus on the one-dimensional configuration, where this challenge has long existed in the combustion community. We consider a model of solid propellant combustion, which possesses the characteristic difficulties encountered in the homogeneous or spray combustion cases, with the added complication of an active interface. The system obtained after semi-discretisation in space is shown to be differential–algebraic of index 1. A numerical strategy relying on stiffly accurate Runge–Kutta methods is introduced, with a specific discretisation of the algebraic constraints and time adaptation. High order is shown to be reached on all variables, while handling the constraints properly. Three challenging test cases are investigated: ignition, limit cycle, and unsteady response with detailed gas-phase kinetics. We show that the time integration method can greatly affect the ability to predict the dynamics of the system. The proposed numerical strategy exhibits high efficiency and accuracy for all cases compared to traditional schemes used in the combustion literature.

Color-selective optical edge detection enabled by thermally stimulated cholesteric liquid crystals

Optical edge detection can significantly compress the data volume and is highly pursued in imaging processing. The commonly used methods extract the optical edge information but lose the capability to distinguish colors, which is another key information for imaging. Here, a design for color-selective optical edge detection is proposed and demonstrated with a cholesteric liquid crystal q-plate. The corresponding optical edge detection exhibits a narrow reflection band characteristic due to the one-dimensional photonic crystal configuration of the cholesteric liquid crystal. The monochromatic band is thermally and reversibly tuned ∼300 nm within 5.3 °C. Color-selective optical edge detection is verified by a series of chromatic images. This work introduces a thermally responsive liquid crystal device to release the color dimension of optical edge detection, which may upgrade existing imaging processing techniques.

Mo-doped one-dimensional needle-like Ni3S2 as bifunctional electrocatalyst for efficient alkaline hydrogen evolution and overall-water-splitting

Hydrogen energy plays an important role in clean energy system and is considered the core energy source for future technological development owing to its lightweight nature, high calorific value, and clean combustion products. The electrocatalytic conversion of water into hydrogen is considered a highly promising method. An electrocatalyst is indispensable in the electrocatalytic process, and finding an efficient electrocatalyst is essential. However, the current commercial electrocatalysts (such as Pt/C and Ru) are expensive; therefore, there is a need to find an inexpensive and efficient electrocatalyst with high stability, corrosion resistance, and high electrocatalytic efficiency. In this study, we developed a cost-effective bifunctional electrocatalyst by incorporating molybdenum into nickel sulfide (Ni3S2) and subsequently tailoring its structure to achieve a one-dimensional (1D) needle-like configuration. The hydrogen production efficiency of nickel sulfide was improved by changing the ratio of Mo doping. By analyzing the electrochemical performance of different Mo-doped catalysts, we found that the Ni3S2-Mo-0.1 electrocatalyst exhibited the best electrocatalytic effect in 1 M KOH; at a current density of 10 mA cm−2, it exhibited overpotentials of 120 and 279 mV for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively; at a higher current density of 100 mA cm−2, the HER and OER overpotentials were 396 and 495 mV, respectively. Furthermore, this electrocatalyst can be used in a two-electrode water-splitting system. Finally, we thoroughly investigated the mechanism of the overall water splitting of this electrocatalyst, providing valuable insights for future hydrogen production via overall-water-splitting.

Global sensitivity analysis of a one-dimensional ocean biogeochemical model

Ocean biogeochemical (BGC) models are a powerful tool for investigating ocean biogeochemistry and the global carbon cycle. The potential benefits emanating from BGC simulations and predictions are broad, with significant societal impacts from fisheries management to carbon dioxide removal and policy-making. These models contain numerous parameters, each coupled with large uncertainties, leading to significant uncertainty in the model outputs. This study performs a global sensitivity analysis (GSA) of an ocean BGC model to identify the uncertain parameters that impact the variability of model outputs most. The BGC model Regulated Ecosystem Model 2 is used in a one-dimensional configuration at two ocean sites in the North Atlantic (BATS) and the Mediterranean Sea (DYFAMED). Variance-based Sobol' indices are computed to identify the most influential parameters for each site for the quantities of interest (QoIs) commonly considered for the calibration and validation of BGC models. The most sensitive parameters are the chlorophyll to nitrogen ratio, chlorophyll degradation rate, zooplankton grazing and excretion parameters, photosynthesis parameters, and nitrogen and carbon remineralization rate. Overall, the sensitivities of most QoIs were similar across the two sites; however, some differences emerged because of different mixed layer depths. The results suggest that implementing multiple zooplankton function types in BGC models can improve BGC predictions. Further, explicitly implementing heterotrophic bacteria in the model can better simulate the carbon export production and CO2 fluxes. The study offers a comprehensive list of the most important BGC parameters that need to be quantified for future modeling applications and insights for BGC model developments.

Computational diagnostics for flame acceleration and transition to detonation in a hydrogen/air mixture

A new computational diagnostic method for pressure-induced compressibility is proposed by projecting its local contribution to the chemical explosive mode (CEM) in the chemical explosive mode analysis (CEMA) framework. The new method is validated for the study of detonation development during the deflagration-to-detonation transition (DDT) process. The flame characteristics are identified through the quantification of individual CEM contributions of chemical reaction, diffusion, and pressure-induced compressibility. Numerical simulations are performed to investigate the DDT processes in a stoichiometric hydrogen-air mixture. A Godunov algorithm, fifth-order in space, and third-order in time are used to solve the fully compressible Navier-Stokes equations on a dynamically adapting mesh. A single-step, calibrated chemical diffusive model (CDM) described by Arrhenius kinetics is used for energy release and conservation between the fuel and the product. The new diagnostic method is first applied to one-dimensional (1D) canonical flame configurations followed by two-dimensional (2D) simulations of DDT in an obstructed channel where different detonation initiation scenarios are examined using the new CEMA projection formulation. Detailed examinations of the idealized configuration of detonation initiation through shock focusing mechanism at a flame front are also studied using the new formulation. A comparison of the currently proposed CEMA projection and the original formulation by the authors suggests that including the pressure-induced compressibility is essential for the use of CEMA in DDT process. The results also show that the new formulation of CEMA projection can successively capture the detonation initiation through either a gradient mechanism or a direct initiation mechanism, and therefore can be used as an effective local analytical tool for the computational diagnostics of detonation initiation in a DDT process. It was found that detonation development is characterized by a strong contribution of chemistry role to the CEM which is pivotal to the initiation of detonation. The role of compressibility is found enhanced at the edge of the detonation front where diffusion was found to have minimal effects on detonation development. Novelty and Significance StatementA new computational diagnostic method for pressure-induced compressibility is proposed by projecting its local contribution to the chemical explosive mode (CEM) in the chemical explosive mode analysis (CEMA) framework. The proposed method is tested and validated for the study of detonation development during the deflagration to detonation transition (DDT) process. The new method is found to be an effective local analytical tool for the computational diagnostics of detonation initiation in a DDT process. The proposed method is versatile and can be used on various different platforms which makes this study more impactful.

Mathematical Model of Equilibrium Plasma Configurations in Magnetic Traps and Their Stability Analysis

The paper presents a review of numerical investigations of a special class of magnetic field-based plasma confinement traps in which current-carrying conductors are immersed in plasma. These traps are referred to as Galatea traps, as proposed by A. I. Morozov. The investigations are presented as applied to a cylinder with two conductors parallel to the axis, which is a straightened analog of a toroidal Galatea-belt trap. The mathematical model of equilibrium is based on a boundary value problem for the two-dimensional elliptic Grad–Shafranov equation, which is solved numerically. Of main interest are various approaches to the stability analysis of magnetoplasma configurations in a trap and the dependence of stability on the geometry and parameters of the problem. We analyze the linear-approximation stability of one-dimensional configurations surrounding a conductor and of two-dimensional configurations in a Galatea-belt trap. The main result of calculations in various problem statements is that the ratio of the characteristic gas and magnetic pressures under which stability occurs is bounded from above. We give a brief account of the main results published in recent years and present new results obtained recently.

Poroelastic behavior of skin tissue in response to pressure driven flow

Better understanding of skin tissue's permeability and poroelasticity could help advance biomedical technologies concerning skin such as intradermal injection and grafting. We applied a pressure driven fluid flow across skin tissue's epidermal and dermal layers in a simple one-dimensional configuration, while measuring the resulting flow rate and capturing cross sectional optical coherence tomography (OCT) images of the tissue's deformation. Digital image correlation was used to analyze the OCT images and via a novel method, image analysis corrected for the change in the tissue's refractive index, which occurred due to flow-induced deformation, thus providing accurate one-dimensional depth-wise deformation profiles. Skin tissue was found to exhibit a nonlinear relationship between pressure and the resulting fluid flow rate, where the increase in flow rate with pressure decreased as pressure increased. The skin tissue was observed to experience compressive strain closest to the supported base, with magnitudes increasing with increasing driving pressure, and the tissue near the free surface experienced relatively little strain. Permeability was found to follow an exponential permeability-volumetric strain relationship with material constants: k0 (initial uniform permeability) of 9.6 × 10−15 m2 and m (extent of nonlinearity for the permeability–strain relationship) of 2.94. Darcy's law and the permeability–strain relationship were used to analyze results with good similarity between observed and calculated flowrates. This work presents a novel and direct method of characterizing soft tissue permeability and provides a fundamental understanding to skin behavior under pressurized driving fluid, which can be generalized to study or model other geometries of induced flow through skin tissue.

Electrospray Deposition of PEDOT:PSS on Carbon Yarn Electrodes for Solid-State Flexible Supercapacitors.

The increasing demand for flexible electronic devices has risen due to the high interest in electronic textiles (e-textiles). Consequently, the urge to power e-textiles has sparked enormous interest in flexible energy storage devices. One-dimensional (1D) configuration supercapacitors are the most promising technology for textile applications, but often their production involves complex synthesis techniques and expensive materials. This work unveils the use of the novel electrospray deposition (ESD) technique for the deposition of poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS). This deposition methodology on conductive carbon yarns creates flexible electrodes with a high surface area. The deposition conditions of PEDOT:PSS were optimized, and their influence on the electrochemical performance of a 1D symmetric supercapacitor with a cellulose-based gel as an electrolyte and a separator was evaluated. The tests herein reported show that these capacitors exhibited a high specific capacitance of 72 mF g-1, an excellent cyclability of more than 85% capacitance retention after 1500 cycles, and an outstanding capability of bending.

Finite-size corrections to defect energetics along one-dimensional configuration coordinate

Recently, effective one-dimensional configuration coordinate diagrams have been utilized to calculate the line shapes of luminescence spectra and nonradiative carrier capture coefficients via point defects. Their calculations necessitate accurate total energies as a function of configuration coordinates. Although supercells under periodic boundary conditions are commonly employed, the spurious cell size effects have not been previously considered. In this study, we have proposed a correction energy formalism and verified its effectiveness by applying it to a nitrogen vacancy in GaN.

Waveguide Antenna Topologies for Distributed High-Frequency Near-Field Communication and Localization

High-frequency near-field communication is an inherently short-range technology. However, the total capture volume can be increased with traveling-wave antennas. Here, we report on analysis, design, and measurements of flexible waveguide antennas and discuss their performance for near-field communication and localization. The antennas comprise sections of coaxial transmission lines loaded periodically with field-generating inductive networks. Several topologies were compared to each other theoretically and the best-performing candidate was selected to fabricate antennas between 5 and 48 meters long, each containing 15 read nodes. Waveguiding properties of the antennas were measured and agreement with theory was demonstrated. Afterwards, each antenna was integrated with a custom NFC reader and shown to be capable of near-field communication with and localization of commercial off-the-shelf transponders compliant with ISO 14443 Type A protocol. The transverse detection range was 10 cm with 1 W input RF power. Both one-dimensional and quasi two-dimensional configurations were tested. The proposed antennas are flexible, scalable, have low loss, and could be used for near-field communication, identification, and tracking of distributed and mobile tags.

Computation and prediction of intrinsic thermoacoustic oscillations associated with autoignition fronts

A sequential combustor architecture consists of two longitudinally staged combustion zones featuring a propagation-stabilized flame in the first stage and an autoignition-stabilized flame in the second (reheat) stage. This layout allows for increased fuel flexibility compared to single-stage systems and enables clean and efficient combustion of carbon-free fuels such as hydrogen. Interactions between the autoignition-stabilized flame and the acoustic field created by the unsteady ignition front and the surrounding boundaries can result in self-sustained (thermoacoustic) flame oscillations in the reheat stage of the sequential burner, causing performance losses and structural damage. In this paper, an intrinsic flame-acoustic feedback mechanism causing self-sustained thermoacoustic oscillations in a reheat combustor is studied. The intrinsic thermoacoustic feedback is established when an acoustic wave generated by the unsteady ignition front travels upstream and introduces local temperature, pressure and velocity perturbations in the unburnt mixture. These modulate the ignition chemistry and the front kinematics and thus, in turn, act as a new source of perturbation for the ignition front that generates heat release rate oscillations and upstream-traveling acoustic disturbances, closing the feedback loop. Compressible reactive Euler equation computations of autoignition fronts in a simple one-dimensional reheat combustor configuration with fully non-reflecting boundaries are first performed to demonstrate and characterize the intrinsic thermoacoustic oscillations associated with autoignition fronts. These computations show that the autoignition front exhibits distinct harmonic thermoacoustic oscillations which tend to become unstable at some conditions. Next, frequencies and growth rates of the intrinsic thermoacoustic oscillations in the linear regime are predicted using a hybrid approach with flame response transfer functions taken from a forced Euler calculation and using a linearized Euler equation framework to describe the combustor acoustic field. The predictions of the intrinsic thermoacoustic eigenvalue from the linearized Euler equation framework show good agreement with the linear behaviour of these oscillations observed in the Euler computations. The findings of the present work are useful both from a fundamental standpoint for prediction of intrinsic thermoacoustic instabilities and from an industrial perspective for prevention of thermoacoustic instabilities in staged combustion systems.

Modulation instability in nonlinear flexible mechanical metamaterials.

In this paper, we study modulation instabilities (MI) in a one-dimensional chain configuration of a flexible mechanical metamaterial (flexMM). Using the lumped element approach, flexMMs can be modeled by a coupled system of discrete equationsfor the longitudinal displacements and rotations of the rigid mass units. In the long wavelength regime, and applying the multiple-scales method we derive an effective nonlinear Schrödinger equationfor slowly varying envelope rotational waves. We are then able to establish a map of the occurrence of MI to the parameters of the metamaterials and the wave numbers. We also highlight the key role of the rotation-displacement coupling between the two degrees of freedom in the manifestation of MI. All analytical findings are confirmed by numerical simulations of the full discrete and nonlinear lump problem. These results provide interesting design guidelines for nonlinear metamaterials offering either stability to high amplitude waves, or conversely being good candidates to observe instabilities.