Perpendicular Component Research Articles

Rayleigh‐Taylor Instability Observed at the Dayside Magnetopause Under Northward Interplanetary Magnetic Field

AbstractUnder northward interplanetary magnetic field, periodical fluctuations with the period of 85 s have been observed by one of the Time History of Events and Macroscale Interactions during Substorms spacecraft at the dayside magnetopause when the solar wind dynamic pressure suddenly dropped. The observed magnetic field distortions, characterized by the compression of the main component as well as the flapping of the perpendicular components, are in line with the theoretical predictions of the Rayleigh‐Taylor (R‐T) instability excited at the magnetopause. With the convective electric field and the mean electric field removed, the perturbations in the electric field are identified as typical two sinusoidal signals with a 90° phase difference, consistent with previous prediction of the attendant electrostatic field arising from the R‐T instability. The transverse motions of the plasmas resulting from the electric drifting driven by the electrostatic field are observed both in pitch‐angle distributions and in distribution functions. The growth rate of the R‐T instability is about 43 s, implying that the instability has time to grow during the disturbances. Using the Gauss theorem, the calculated net charge density based on the electric field observation is one part of 27 compared to the totally observed plasma density, indicating that only a tiny fraction of the charge separates to set up the electrostatic field, which is due to a collective effect in the plasma.

Anisotropic and Finite Effects on Intermolecular Vibration and Relaxation Dynamics: Low-Frequency Raman Spectroscopy of Water Film and Droplet on Graphene by Molecular Dynamics Simulations.

The structural and dynamical properties of water can be greatly altered by the anisotropic interfacial environment. Here, we study the intermolecular vibration and relaxation dynamics of a water film and a water droplet on a graphene surface based on low-frequency Raman spectra calculated from molecular dynamics simulations. The calculated Raman spectra of the interfacial water systems show a weakened libration peak and an enhanced intermolecular hydrogen bond (HB) stretching peak compared to the spectrum of bulk water, which are attributed to softened orientation motion. We also find that the collective polarizability relaxation in the droplet is much slower than that in the film and bulk, which is completely different from the collective dipole relaxation. The slow relaxation is due to a positive correlation between the induced polarizabilities of distinct molecules caused by the global and anisotropic structural fluctuations of the water droplet. Furthermore, we find that the two-dimensional HB network by the orientation-ordered interfacial water molecules leads to different intermolecular vibration dynamics between the parallel and perpendicular components. The present theoretical study demonstrates that low-frequency Raman spectroscopy can reveal the anisotropic and finite effects on the intermolecular dynamics of the water film and droplet.

Quantum version of transport coefficients in Nambu–Jona-Lasinio model at finite temperature and strong magnetic field

We have estimated parallel and perpendicular components of electrical conductivity and shear viscosity of quark matter at finite magnetic field and temperature by using their one-loop Kubo expressions in the framework of Nambu–Jona-Lasinio (NJL) model. At finite magnetic field, a non-trivial medium dependence of those quantities can be found. Previously these NJL-profiles have been addressed in relaxation time approximation, where cyclotron motion of quarks with medium dependent mass plays the key role. With respect to the earlier estimations, the present work provides further enriched profiles via Kubo framework, where field theoretical descriptions of quark transport with medium dependent mass and (Landau) quantized energy have been identified as the key ingredients. Hence the present study can be considered as the complete quantum field theoretical description of the transport coefficients in the framework of NJL model at finite temperature and magnetic field.

Angular Momentum Variation of the Milky Way Thick Disk: The Dependence of Chemical Abundance and Evidence of the Inside-out Formation Scenario

We investigate the angular momentum of mono-abundance populations (MAPs) of the Milky Way thick disk by using a sample of 26,076 giant stars taken from APOGEE Data Release (DR) 17 and Gaia early DR3. The vertical and perpendicular angular momentum components, L Z and L P , of the MAPs in narrow bins have significant variations across the [α/M]–[M/H] plane. L Z and L P systematically change with [M/H] and [α/M] and can be alternatively quantified by the chemical gradients: d[M/H]/dL Z = 1.2 × 10−3 dex kpc−1 km−1 s, d[M/H]/dL P = −5.0 × 10−3 dec kpc−1 km−1 s, and d[α/M]/dL Z = −3.0 × 10−4 dex kpc−1 km−1 s, d[α/M]/dL P = 1.2 × 10−3 dec kpc−1 km−1 s. These correlations can also be explained as the chemical dependence of the spatial distribution shape of the MAPs. We also exhibit the corresponding age dependence of the angular momentum components. Under the assumption that the guiding radius (R g ) is proportional to L Z , this provides direct observational evidence of the inside-out structure formation scenario of the thick disk, with dR g /dAge = −1.9 kpc Gyr−1. The progressive changes in the disk thickness can be explained by the upside-down formation or/and the consequent kinematical heating.

New analysis of the [formula omitted]C[formula omitted]O[formula omitted] (B[formula omitted] - X[formula omitted]) system: Spin-orbit and spin-rotation coupling of the X[formula omitted] state

In the present work a new experimental and theoretical analysis of the B2Σ+→ X2Σ+ system of the molecular ion 12C16O+ is performed. New transitions regarding the vibrational levels v′=4 of the B2Σ+ electronic state and the vibrational level v″=7 of the electronic state X2Σ+ have been recorded. For rationalising the experimental observations, molecular structure calculations were carried out and, from them, a detailed investigation about the fine structure of rotational levels of the X2Σ+ could be performed. For such, the spin-rotational constant, γ, is characterised through the Δg⊥ calculation, the perpendicular component of the electronic g-tensor, in combination with Curl’s relation. At equilibrium geometry, the present Δg⊥ is computed using the multireference configuration interaction wavefunction to be −2430 ppm in agreement with the experimental one [−2344 ppm]. The R-dependence of the g-tensor has been explored in order to estimate the theoretical γv (v=0–7). In addition, the importance of the lowest Π states in this kind of calculation is widely discussed. A comparison between experiment and theory is presented, validating our findings and the methodology employed in our analysis.

Traces of health-A landscape design task as a diagnostic aid for detecting mental burden? A qualitative focus group study.

Mental disorders are most common causes of illness worldwide. Studies on art and drawing tasks, such as the tree-drawing test have already proven their prognostic quality for the diagnosis of Alzheimer's disease, depression or trauma. In the depiction of art in public space, gardens and landscapes are one of the oldest human forms of artistic expression. This study thus aims at exploring the impact of a landscape design task as a prognostic tool to detect mental burden. A total of 15 individuals (eight female) aged between 19 and 60 years completed the Brief Symptom Inventory BSI-18 and the State Trait Anxiety Inventory (STAI-S) before being asked to design a landscape in a 3 × 3 m squared area. Material to be used included plants, flowers, branches, and stones. The complete process of landscape design was videotaped and the tapes were analyzed in a two-step focus group analysis from a group of gardening trainees, psychology students and students of arts therapies. Results were condensed in a second step into major categories. Scores of the BSI-18 showed a range of 2-21 points and STAI-S scores ranged between 29 and 54 points indicating a light to moderate mental burden. Focus group participants identified three mutually perpendicular major components associated with mental health: "Movement and Activity," "Material Selection and Design," and "Connectedness to the task." In a subsample of the three least and three most mentally stressed subjects (based on their GSI and STAI-S scorings), clear differences were found in body posture, action planning and the choice of material and aspects of design. In addition to the well-known therapeutic potential of gardening, this study for the first time showed that gardening and landscape design contains diagnostic elements. Our preliminary findings are in coherence with similar research indicating a high association of movement and design patterns with mental burden. However, due to the pilot nature of the study, the results should be interpreted cautiously. Based on the findings further studies are currently planned.

Semiconducting CdS quantum dots as a guest in a four ring bent-core nematic medium: modified dielectric and elastic properties

The nematic phase of the bent-core family proves to be particularly fascinating due to its distinct properties in comparison to its calamitic counterpart. Here we revealed after the dispersion of semiconducting CdS QD an achiral unsymmetrical (4′-fluoro phenyl azo) phenyl-4-yl 3-[N-(4′-n-hecyloxy two hydroxybenzylidene)amino]-2-methylbenzoate (6-2M-F) a bent-core nematic (BCN) liquid-crystalline medium made of bent-shaped molecules with short cores and low bend angles. These molecules are on the cusp between conventional bent-core molecules and rod-like molecules, with characteristics somewhere in between, resembling hockey sticks. The threshold voltage dielectric permittivity and elastic constants of pure BCN have been considerably influenced by semiconductor nanoparticles. The threshold voltage of nano-disperse BCN has decreased with QD doping, and we know that the low operation voltage is one of the key considerations in the development of mobile liquid crystal display technology. Similar to other BCNs with smectic-like clusters previously described, the elastic anisotropy for 6-2M-F is negative; however, the insertion of CdS QDs causes the anisotropy to become very positive (bend elastic constant > splay elastic constant ). While the parallel component of permittivity has declined with doping, the perpendicular component of permittivity has increased, leading to a considerable reduction in dielectric anisotropy in the nanocomposite, which implies the effect on nematic ordering due to the interaction between CdS QDs and the LC molecules.

On gyrokinetic-fluid model for electromagnetic fluctuations in magnetized plasmas

The hybrid gyrokinetic-fluid model (termed as GK-E&B) for simulating low-frequency electromagnetic fluctuations (Chen et al 2021 Sci. China Phys. Mech. Astron. 64 245211) is revisited, with emphasis on the self-consistency between the gyrokinetic ordering and magnetohydrodynamic equations. It is found that, contrary to the previous results, the parallel electric field equation is a Poisson-like equation in general for the typical electromagnetic microturbulence with wavelengths of the order of the thermal ion Larmor radius. Although the GK-E&B suffers no conventional Ampère cancellation issue since it employs the gauge-free gyrokinetic equation formulated in terms of electromagnetic fields, the balance between parallel electric field and electron pressure gradient must be accurately captured. Furthermore, the ion parallel current correction is shown to be essential to the ion sound wave branch in the GK-E&B model, and the compressional component of magnetic field fluctuation should be computed from the perpendicular component of Ampère’s law, instead of the Faraday’s law.

Projection to extract the perpendicular component (PEPC) method for extracting kinetics from time-resolved data

Time-resolved x-ray liquidography (TRXL) is a potent method for investigating the structural dynamics of chemical and biological reactions in the liquid phase. It has enabled the extraction of detailed structural aspects of various dynamic processes, the molecular structures of intermediates, and kinetics of reactions across a wide range of systems, from small molecules to proteins and nanoparticles. Proper data analysis is key to extracting the information of the kinetics and structural dynamics of the studied system encrypted in the TRXL data. In typical TRXL data, the signals from solute scattering, solvent scattering, and solute–solvent cross scattering are mixed in the q-space, and the solute kinetics and solvent hydrodynamics are mixed in the time domain, thus complicating the data analysis. Various methods developed so far generally require prior knowledge of the molecular structures of candidate species involved in the reaction. Because such information is often unavailable, a typical data analysis often involves tedious trial and error. To remedy this situation, we have developed a method named projection to extract the perpendicular component (PEPC), capable of removing the contribution of solvent kinetics from TRXL data. The resulting data then contain only the solute kinetics, and, thus, the solute kinetics can be easily determined. Once the solute kinetics is determined, the subsequent data analysis to extract the structural information can be performed with drastically improved convenience. The application of the PEPC method is demonstrated with TRXL data from the photochemistry of two molecular systems: [Au(CN)2−]3 in water and CHI3 in cyclohexane.

Comparative Study of Guided Electromagnetic Wave Propagation for Two Models of an Open Tape Helix

Rigorous methods to solve the homogeneous boundary value problems and the techniques to resolve illposed mathematical issues arising in the problem formulation of electromagnetic wave propagation of an Open tape helix slow wave structure with anisotropically conducting and completely conducting model is presented. The dispersion equation of both the models require convergent coeefficients of the infinte linear homogeneous equations whose determinant of the coefficent matrix is zero. The coefficient matrix of the anisotropically conducting model is rapidly convergent, while in the case of completely conducting model, the matrix entries which are infinite summation series representations turns out to be divergent, the not so well-posed boundary value problem is regularised with the method of mollification functions. The dispersion characteristics are plotted after truncating the infinite series expansions to adequate number of terms and summing the terms of converging series expansions(after regularization in the case of the completely conducting tape-helix model) in dispersion equations. The tape-current distribution for both models are estimated from the null-space vector of the truncated coefficient matrix corresponding to a particular (β <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> – <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">k</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> ) root of the dispersion equation. A comparison of the numerical results for both models show that the neglect of the perpendicular tape-current density component entails a substantial modification of the dispersion characteristics of guided waves supported by an open tape helix.

Effect of molecular aspect ratio on structure, dynamics and phase stability of thermotropic liquid crystals studied by molecular dynamics simulation

Due to the importance of liquid crystals in modern technology and food industry, understanding their structural and dynamical properties are scientifically important. In this study, we applied extensive molecular dynamics simulations to infer the effect of the molecular elongation on the formation, stability and dynamics of liquid crystal mesophases in a system of Gay-Berne model mesogens with parameters GB (k,k′=20,μ=1,ν=1). Four aspect ratio values, k=2,3,4.4 and 5, were studied at pressure P*=4. Thermodynamics properties, the order parameter and pair distribution functions (both translational and positional), helped to identify phases, hysteresis, and consequently phase diagrams. By increasing aspect ratio from 2 to 5, nematic and smectic phases were induced and all transition temperatures were shifted to higher values, hence, the range of stability of the nematic and smectic mesophases became wider. The analysis of the coordination numbers and angular distribution functions showed that the structure of the solid phase of system with k=2 at lowest temperatures was fcc which by increasing the aspect ratio changed to a complete hexagonal in-layer structure. Moreover, by increasing the axial ratio of particles, decoupling between the principal components of diffusion coefficients increased, where it reflects an increase in the molecular orientational order in the system with higher k. The effect of increasing aspect ratio was more pronounced on inter-layers diffusion rather than the in-layers. In all mesophases parallel components of diffusion coefficients were greater than the perpendicular components. We analyzed the results based on the existing theoretical descriptions and experimental observations.

Mass transfer enhancement in spacer-filled membrane channels by flow oscillation induced vortex shedding: Numerical study of the effect of amplitude

Techniques inducing unsteady flow have shown potential for promoting vortex shedding in membrane channels, affecting the boundary layer and increasing mass transfer. This work reports a CFD study of the effect of the characteristics of an oscillating flow (i.e., frequency and amplitude) on the occurrence of vortex shedding. The implications of imposing an oscillating flow are analysed by comparing mass transfer enhancement and required pumping power. Results show that the resonant frequency for the perpendicular velocity component does not maximise mass transfer, but it yields a significant increase. For Re = 300, a normalised amplitude of 0.01 appears as a balanced trade-off between mass transfer and pressure drop. The location of onset of vortex shedding in the channel moves upstream as the amplitude increases. Mass transfer reaches an upper limit as the amplitude increases, when the onset of vortex shedding reaches the first filament. The phenomena taking place in a 2D spacer-filled membrane channel, and their implications for real-world applications, are discussed.

Substorm Induced Nighttime Plasma Flow Pulsations Observed by ROCSAT‐1 at Topside Ionosphere

The Republic of China Satellite-1 orbiting at 600 km topside ionosphere has observed the topside ionospheric plasma flow pulsations induced by the substorm onsets. These pulsation events indicated that the plasma flow pulsations mainly oscillate in the two mutually perpendicular directions with respect to the geomagnetic field lines. The field-aligned flow as well as the ion density indicates almost no variation. This implies that the pulsation events are of Alfven wave in nature. The Hilbert-Huang transform analysis is applied to study the dominant wave frequencies and the polarization in the two perpendicular components of plasma flows (i.e., the perturbed electric/magnetic fields). The hodograms of the polarization in the Pi1 frequency is shown to be linearly polarized, while the left-handed polarization is seen in the Pi2 frequencies that are in harmonic relationship. These plasma flow pulsations in the nighttime topside ionosphere are caused by the field-line-resonance magnetic field pulsations converted from the inward propagated compressional disturbance across the nighttime magnetosphere/plasmasphere which is originated at the near-Earth magnetotail at the substorm onset.

Dynamic resistance and total loss in small REBCO pancake and racetrack coils carrying DC currents under an AC magnetic field

In many high-temperature superconducting applications, REBCO (Rare-earth barium copper oxide) coils carry DC currents under AC magnetic fields, such as the field winding of rotating machines, linear synchronous motors and the electro-dynamic suspension system of maglev. In such operating conditions, REBCO coils generate AC loss—total loss which includes the magnetization loss due to the shielding currents, and the dynamic loss arising from dynamic resistance caused by the interaction of DC currents and AC magnetic fields. In this work, dynamic resistance and total loss in a small double pancake coil (DPC) and a small double racetrack coil (DRC) are investigated via experiments in the temperature range between 77 K and 65 K. The DC currents are varied from zero to 70% of the self-field critical currents of the REBCO coils, with AC magnetic fields up to 100 mT. The experimental results in the DPC are well supported by the finite element simulation results using 3D T-A formulation. Our results show that the critical current of the DRC is approximately 2%–5% higher than that of the DPC in the temperature range. For given experimental conditions, the magnetization loss in both coils is much greater than the dynamic loss. The dynamic loss and magnetization loss in the DRC are greater than those in the DPC, which we attribute to the large perpendicular magnetic field component in the straight sections of the DRC.

Relationship between drift kinetics, gyrokinetics and magnetohydrodynamics in the long-wavelength limit

Gyrokinetic theories, even ‘global’ models, typically rely on a separation in scale (in perpendicular wavelength) between the fluctuations and the system scale. In such models direct simulation of system-scale dynamics like magnetohydrodynamic (MHD) motion is formally not consistent. Drift-kinetic theory, on the other hand, may be directly applied to model system-scale MHD-ordered behaviour. I review the long-wavelength limit of standard gyrokinetics and drift kinetics to present the relationships between these theories in an elementary fashion. This provides a pathway to global gyrokinetic modelling, resulting in an approach that is structurally similar to kinetic MHD, and I present dynamical equations for solving global field evolution in this framework. Departures from certain earlier global gyrokinetic theories include the appearance of magnetosonic (fast) modes, and the cross-coupling of the parallel and perpendicular currents with perpendicular and parallel magnetic field components. A periodic two-dimensional testcase is outlined as a benchmarking and implementation target, to help clarify practical aspects of these theories, with minimal complexity in terms of boundary conditions, and a proof-of-principle implementation of a field-solver is exhibited. To motivate this work, I first illustrate certain limitations of existing global gyrokinetic frameworks and directly identify how scale separation approximations lead to certain ‘missing’ system-scale field terms in global gyrokinetics, largely as a result of simplifications associated with the field representation in terms of $A_{\|}$ and $B_{\|}$ . As a result, the currents in the gyrokinetic Ampère's law resulting from a gyrokinetic equilibrium distribution do not match the currents implied by Ampère's law in a force-balance MHD equilibrium. I present a simple choice of equilibrium distribution function whose drift-kinetic currents are consistent with MHD currents; a specific Grad–Shafranov equilibrium is used to illustrate the size of the components of the parallel currents.

Polarized neutron scattering study of hollow Fe3O4 submicron spherical particles

We report results of polarized small-angle and wide-angle neutron scattering experiments at T = 10 and 300 K for 420 nm-sized hollow Fe3O4 spherical particles. Each hollow particle is a mesocrystal, which is composed of small nanoparticles with nearly the same crystallographic orientation. Polarized neutron experiments allow us to evaluate magnetic correlations of parallel and perpendicular magnetization components with respect to magnetic field during magnetization process. Small-angle neutron scattering reveals that as the magnetic field decreases from a saturation field of 10 kOe, the perpendicular magnetization component maximizes around zero applied field, whereas the parallel component minimizes. This behavior was observed below and above Verwey transition temperature of ∼ 120 K. Calculations of neutron intensities for vortex structures suggest the reorientation of the vortex core towards the magnetocrystalline anisotropy axis from the magnetic field direction at low applied fields. Moreover, a magnetic domain length obtained from the wide-angle scattering is of the order of 30-40 nm and comparable to the size of the small nanoparticles forming a hollow sphere, suggesting that magnetic correlations within the small nanoparticles always retain during magnetization process.

Hydrokinetic energy harvesting from flow-induced vibration of a hollow cylinder attached with a bi-stable energy harvester

This paper proposes an electromagnetic bi-stable energy harvester (EBEH) with tunable stiffness for scavenging the hydrokinetic energy from flow-induced vibration (FIV) scenarios. A mathematical model of the magneto-mechanical–electrical coupling system is established considering vortex-induced forces, wake oscillator effect, negative linear stiffness and hybrid excitations. The bi-stable system with adjustable barrier height is employed to enhance state-of-the-art energy scavenging performance of vortex-induced vibration (VIV). Preliminary verification with regard to VIV within a lock-in wind speed range has been implemented by means of CFD simulation. The nonlinear energy transfer capacity and energy conversion performance of the FIV based EBEH are evaluated under solitary vortex-induced vibration (VIV) and hybrid excitations. Simulation results show that EBEH with larger negative linear stiffness has higher energy conversion efficiency and target energy transfer capacity in a wide range of inlet velocities. The large amplitude and low frequency vibration of the VIV of the cylinder is mainly caused by the lift pulsation, meanwhile the small amplitude and high frequency galloping are caused by the perpendicular component pulsation of the drag force. The fluctuations of the lift/drag coefficient at different inflow velocities are directly related to the VIV or galloping amplitude of the cylindrical bluff body. Specifically, the frequency fD is approximately twice the frequency fL in a wide inflow velocity range; The amplitude of fluctuating lift exceeds 2.0 in a wide range of inflow velocity from 1.0 m/s to 20 m/s. The nonlinear energy transfer efficiency of the FIV based EBEH with smaller barrier height is greater than 60% when the inflow velocity ranges from 20 m/s to 30 m/s. The nonlinear energy transfer capability of EBEH with appropriate negative stiffness outperforms its counterpart of cubic stiffness more than ten times. The maximum mean harvested power achieved from EBEH can be increased over 900% than that of the cubic stiffness case. Regardless of negative stiffness alteration, the optimal external load that maximizes the EBEH output power is around 50 Ω. Additionally, when the vortex-induced vibration cannot be woken, intervention of base excitation causes considerable chaotic motion consisting of aperiodic intra-well and inter-well snap-throughs at low inflow velocities. Nevertheless, nonlinear energy transfer efficiency of bi-stable energy harvester is slightly crippled with the increase of the base excitation intensity.

Wind effects on the long‐distance migration of GPS‐tracked adult ospreys Pandion haliaetus from Germany

Birds that repeatedly visit distinct places along their migratory routes in consecutive years must be able to navigate to these places and respond appropriately to unfavourable wind conditions. This study analysed the migratory routes, repeatedly‐visited areas and responses to sidewinds of 15 GPS‐tracked adult ospreys Pandion haliaetus from northeast Germany migrating to their wintering sites in Africa and back. We determined stopovers and intermediate goal areas and performed repeatability estimations on timing and migratory paths in four regions. The orientation behaviour of the ospreys was analysed with regard to perpendicular wind components at each GPS point during autumn and spring migrations. Generalised linear mixed models were used to test the dependence of orientation behaviour on region and the distance to the next goal. The findings showed that ospreys demonstrate high fidelity to migratory paths in autumn and spring, as well as to the timing of migration in autumn; and sidewinds are predominantly compensated, especially when sidewinds are strong. Furthermore, during autumn migration, the proportion of compensation increases in most regions with decreasing distances to the next goal; however, during spring migration, drift behaviour was detected more often at smaller distances to the next goal than at higher distances in the regions Mediterranean and central Europe. In general, ospreys compensate for unfavourable sidewinds and utilise supporting tailwinds on their journeys to the wintering sites in Africa and back to central Europe.

On the concept and potential applications of a photons based device, measuring the velocity vector of an object, moving at high speed in space

The specific case of a photon source, moving at a high velocity v in space in the direction x, while emitting photons in the perfect perpendicular direction y, was considered in (Brauns, 2021). The findings in (Brauns, 2021) resulted in the irrefutable Fig. 12 in (Brauns, 2021), demonstrating the existence of a photon location-of-arrival shift effect MF, as a result of the velocity v. The, in (Brauns, 2021) predicted, MF effect was proven experimentally in (Brauns, 2021). Fig. 12 in (Brauns, 2021) is thus falsifying the view by contemporary science, that M is the photon’s location of arrival, for whatever value of v. The amplitude of MF is in fact dependent from the photon source’s velocity v. It is thus feasible to measure MF and then calculate v. Such innovative velocity measurement concept, based on photons, should be introduced urgently in a broad R&D project, involving the collaboration of experts in multiple fields. A MF shift based, one directional velocity measuring device, needs to be realized first. Thereafter a three-dimensional (x,y,z) configuration can be considered, of three of such “one-directional” based velocity measuring devices, by mounting those perpendicular to one another. When attaching such three dimensional measurement configuration to a material object (being in motion at high speed in space), such configuration will allow to measure the scalar values, of each of the three perpendicular velocity vector components of that object (total velocity vector and its direction of motion). There are multiple important potential applications in space (high velocity objects) and on our planet.

Anisotropic pressure effects on nanoconfined water within narrow graphene slit pores.

There is an increasing interest toward disclosing and explaining confinement effects on liquids, such as water or aqueous solutions, in slit pore setups. Particularly puzzling are the changes of physical and chemical properties in the nanoconfinement regime where no bulk-like water phase exists between the two interfacial water layers such that the density profile across the slit pore becomes highly stratified, ultimately leading to bilayer and monolayer water. These changes must be quantified with respect to some meaningful reference state of water, the most natural one being bulk water at the same pressure and temperature conditions. However, bulk water is a homogeneous liquid with isotropic properties, whereas water confined in slit pores is inhomogeneous, implying anisotropic properties as described by the perpendicular and parallel components of the respective tensors. In the case of pressure, the inhomogeneous nature of the setup results in a well-defined difference between the perpendicular and parallel pressure tensor components that is uniquely determined by the interfacial tension being a thermodynamic property. For bilayer water constrained in graphene slit pores that are only about 1 nm wide, we demonstrate that there exists a thermodynamic point where the pressure tensor of the inhomogeneous fluid, nanoconfined water, is effectively isotopic and the pressure is thus scalar as in the homogeneous fluid, bulk water. This specific point of vanishing effective interfacial tension is proposed to serve as a well-defined reference state to compare the properties of nanoconfined liquids to those of the corresponding bulk liquid at the same (isotropic) pressure and temperature conditions. In future work, this idea could be applied to assess confinement effects on chemical reactivity in aqueous solutions as well as to other nanoconfined liquids in other pores such as layered minerals.