Absorption-dominant electromagnetic interference (EMI) shielding requires simultaneous control of electrical conductivity and impedance matching to suppress secondary electromagnetic pollution. Here, we report a facile, scalable unidirectional evaporation method to fabricate MXene-decorated melamine foams with a continuous, tunable electrical conductivity gradient across the thickness, free of discrete layer boundaries. Directional solvent evaporation induces controlled redistribution of MXene nanosheets within the three-dimensional porous framework, governed by the synergistic effects of capillary, gravity, and Marangoni forces. By systematically tuning evaporation parameters, including temperature, humidity, and MXene concentration, the gradient profile can be regulated to optimize impedance matching and electromagnetic wave attenuation. The resulting composite exhibits outstanding absorption-dominant EMI shielding performance, delivering a stable total shielding effectiveness of 53.84dB across the X-band with an ultralow reflection shielding effectiveness of 0.032dB, corresponding to a high absorptivity of 0.99276. This work provides a general pathway for constructing continuous-gradient architectures in porous composites, offering new opportunities for designing high-performance, low-reflection EMI shielding materials.

This study investigates elastic wave propagation in a generalized magneto-micropolar thermoelastic medium under the combined effects of gravity, initial stress, and a magnetic field. The governing equations, based on the micropolar thermoelastic framework, account for micro-rotation, thermal conduction, electromagnetic interactions, and initial stress, providing a comprehensive description of the medium’s behavior. Analytical expressions for displacement, stress components, and microrotation fields are obtained using the normal mode method, while numerical simulations in Mathematica illustrate how time, magnetic field, gravity, and initial stress influence wave speed, dispersion, and attenuation. The results show that magnetic and micropolar properties reshape wave behavior and introduce distinct dispersive and damping patterns. These findings highlight the complex interplay of multi-physical effects and offer insights for optimizing wave control in microstructured and multifunctional materials, with potential applications in materials science, geophysics, and advanced engineering systems.

While gene expression in bacteria has been shown to be affected by near-zero or extremely high gravity, a mechanism has not been established to date. In larger organisms, gravity-sensing mechanisms usually rely on a dense body applying directional pressure which can be detected by the cell. Herein we demonstrate a means of observing the effect of gravity on cyanobacteria by differential expression of native pigments in response to both gravity and light. We observe that in the cyanobacterium Synechococcus sp. PCC 7002, the distribution of pigmentation within the cell, and across cell colonies, is regulated by combined directional sensing of incoming light, adhesion to a surface via extracellular matrix, and applied external force, including the normal force of gravity applied to the cell. Cells grown on a substrate orient their thylakoids on the cell faces proximal and distal to the substrate and locate both chlorophyll and phycobilins in both of these membrane regions; phycobilins are primarily targeted to the membrane region nearest to the light source, while chlorophyll is preferentially expressed in the region opposite the overall external force applied to the cell. The mechanism for distribution of pigments appears to be regulated by presence of polyphosphate bodies within the cell, and removal of polyphosphate negates the cell's ability to sense external forces. Furthermore, colonial morphology is affected by application of force, with cells responding to the secretions of other cells along a gradient along the expected response to shading. These results represent a critical step toward understanding basal phototrophic regulatory mechanisms of light use and demonstrate, to our knowledge, the first known intracellular directional gravity response mechanism in a prokaryote.

Abstract We explore potential quantum gravity signatures by studying periodic orbits and their GW emissions around a novel regular black hole (BH) featuring a Minkowski core. Using a rational number q , periodic orbits are classified, revealing that the deviation parameter $$\alpha _0$$ α 0 reshapes the bound-orbit region while preserving characteristic “zoom-whirl” structures. Numerical kludge waveforms reveal detectable phase shifts and amplitude modulations induced by quantum gravity effects with radiation reaction breaking orbital periodicity. Faithfulness analysis demonstrates that larger $$\alpha _{0}$$ α 0 and q enhance distinguishability from the Schwarzschild case, and a comparison with Hayward and quantum Oppenheimer–Snyder BHs shows their similar large-scale behaviors yield macroscopically indistinguishable orbits and waveforms.

Abstract We present a study of the effect of metallicity on the determination of the effective temperature and surface gravity of A and B type horizontal-branch stars using the spectroscopic method based on fitting the Balmer line profiles. We used synthetic spectra derived from chemically homogeneous atmospheric models calculated with PHOENIX in the LTE mode at various metallicities [M/H] between −1.5 and +0.5 dex solar. Stars from globular clusters M3 and M13 known to have a low metallicity ([Fe/H] ≃ 1.5 dex solar), observed at the Calar Alto 3.5 m telescope, are used for this purpose. For each star, we determined the atmospheric parameters considering various metallicity values. For stars cooler than 11,500 K and model metallicities between −1.5 and −1.0 dex, the effective temperature and surface gravity differ by a maximum of 200 K and 0.1 dex, respectively. For stars hotter than 11,500 K, considering that their atmospheric metallicities are broadly enhanced due to atomic diffusion, metallicities at ±0.5 dex from solar are of more interest. In this low metallicity range, atmospheric parameters increase, with increasing metallicity, to a maximum of 500 K in effective temperature and 0.25 dex in surface gravity.

Analysis of the Effect of Solar Activity and Lunar Gravity on Earthquakes During the 24th Solar Cycle (2008-2019)

Effects of frontal and sagittal inclination angles on the thermal performance of a single-loop pulsating heat pipe

In this study, we investigate the modulation of sustained turbulence by settling spherical particles using particle-resolved direct numerical simulations. Gravity effects are studied by varying the Galileo number, ${\textit{Ga}}$ , through the particle–fluid density ratio for particles of Taylor-scale size. Particle sedimentation causes enhanced viscous dissipation and anisotropy of the fluid velocity fluctuations, which increase with ${\textit{Ga}}$ . More significantly, the energy spectra exhibit a $\kappa ^{-3}$ scaling, which coexists with the classic $\kappa ^{-5/3}$ law for particle-laden turbulence with weak sedimentation ( ${\textit{Ga}} \lesssim 40$ ); the $\kappa ^{-3}$ scaling widens its wavenumber range with ${\textit{Ga}}$ and dominates the energy spectrum at the highest ${\textit{Ga}}$ under study. The scale-by-scale energy budgets demonstrate that the particle–fluid interactions mainly transfer energy from large to small scales for small settling speeds, whereas the particle sedimentation injects energy into the carrier flow and breaks the isotropic energy distribution for a high ${\textit{Ga}}$ . In particular, the gravity-induced forcing originates vertically elongated structures while disrupting horizontal flow correlations, thereby altering the nonlinear interscale energy transfer and reshaping the energy spectra. For the solid phase, it is found that the particle vertical velocity fluctuations decrease with ${\textit{Ga}}$ , and turbulence has a weaker influence on the mean settling velocity for particles with a higher ${\textit{Ga}}$ . Moderate particle clustering is identified, an observation not changing significantly with the particle settling speed. The collision rate among particles is highest at the strongest particle sedimentation, due to the enhanced relative radial velocity of particle pairs which are preferentially horizontally aligned.

Otoliths within the vestibular system detect the magnitude and orientation of gravity and provide a reference frame for spatial orientation. Although vestibular processing has been studied in altered gravity, little is known about the initial minutes of exposure, when space motion sickness emerges. This study investigated whether otolithic detection is modified in different gravities or by sensory conflicts. Otolithic function was assessed using vestibular-evoked myogenic potentials (VEMPs) recorded from three muscles, reflecting utricular and saccular activity. VEMPs were measured during parabolic flight to assess modified gravity and longitudinal effects associated with otolitho-canalar conflict, and before and after a virtual reality exposure inducing visuo-vestibular conflict. Otolithic reflexes were largely resistant to gravity changes, sensory conflicts, and motion sickness. VEMP amplitudes remained stable, while oVEMP latencies increased ( ~ 1 ms in microgravity; ~0.4 ms post-flight). No differences were observed between motion-susceptible and non-susceptible participants. Baseline otolithic sensitivity predicted cyber-sickness susceptibility but not space-sickness.

The structural design of low- to mid-rise residential buildings in urban areas requires reliable assessment of gravity and lateral load effects, appropriate member sizing, and code-compliant detailing of reinforced concrete elements. This paper presents the analysis and design of a G+4 reinforced concrete residential building modelled in ETABS. The building was idealized as a reinforced concrete framed structure with five storeys, 3.0 m storey height, M30 concrete, Fe500 reinforcement, 150 mm slab thickness, 400 mm x 500 mm beams, and square and rectangular columns of 450 mm x 450 mm and 350 mm x 450 mm, respectively. Loads were assigned in accordance with Indian code provisions for dead, imposed and wind loads, and the frame was analysed for displacement, shear force, bending moment and axial force response. The results indicate that the adopted member sizes are structurally adequate for the considered G+4 residential configuration under the applied load cases, subject to final validation using project-specific soil investigation data, seismic parameters and detailed construction drawings. The study demonstrates the usefulness of ETABS as an integrated modelling, analysis and design environment for reinforced concrete building systems, while emphasizing that software results must be supported by engineering judgement, code checks and quality control during execution.

Gravity affects the flow and the behavior at rest of complex fluids by inducing sedimentation, drainage, and interfacial deformation, which can mask more fundamental physical processes. On Earth, standard countermeasures against gravity come with limitations in terms of possible formulations or the quality and homogeneity of the applied strain. Alternatively, one can run these experiments in free-fall where the effects of gravity are canceled, i.e., under microgravity conditions. In this Short Review, we present several European Space Agency (ESA)-led projects of interest to rheologists that leverage microgravity environments, including interfacial rheology experiments using capillary pressure tensiometers; Fundamental experiments on the coarsening of foams and the intrinsic dynamics and microrheology of emulsion droplets; Multiple granular materials investigations on the transition to jamming, fluidized beds, quasistatic and dilute granular flows; Experiments examining the thermally driven perturbation of soft colloidal glasses; And studies of the aggregation dynamics and migration of soft particles and red blood cells under flow. The microgravity conditions offered by the ESA platforms enabled high-precision measurements of interfacial viscoelasticity; revealed plastic rearrangements in colloidal glasses; detected roaming bubbles in foams, and underlined the progressive arrest of droplet motion in emulsions; uncovered margination effects in blood cell analogues under flow; and rationalized the impact of gravity on convection and fluidization in agitated granular matter. Collectively, these experiments demonstrate the complementarity and the relevance of ESA’s microgravity platforms in expanding the frontiers of soft matter rheology.

We investigate the effect of gravity on the spreading of droplets of yield stress fluids, by performing both microgravity experiments (in a drop tower) and experiments under terrestrial gravity. We study the dependence of the final droplet shape on yield stress and gravity. Droplets are deposited on a thin film of the same material, mimicking a fully wetting surface, and allowing to directly test scaling laws derived from the thin-film equation for viscoplastic fluids, in this limit. Microgravity conditions allow us to vary the two relevant dimensionless numbers independently, the Bond number, B, and the plastocapillary number, J, and thus to disentangle the influence of surface tension from that of the yield stress on the final droplet shapes. Simulations using a viscoelastic model with shear-thinning complement the experiments and show good agreement regarding the droplet shapes. Possible deviations arising in the regime of non-negligible elastic effects and large plastocapillary numbers (large yield stress) are discussed.

Quantum gravity effects are expected to resolve the black hole singularity and the effects may deform the region near but outside the horizon. Applying AdS/CFT correspondence, we see their signatures from the viewpoint of dual conformal field theory. As a regularized geometry, we consider AdS gravastar constructed by gluing AdS-Schwarzschild and de Sitter spacetime. The retarded Green's functions of dual conformal field theory have bulk-cone singularities associated with null trajectories in the bulk and we obtain the singularities specific to a horizonless geometry. We also observe echoes coming from waves reflected behind the photon sphere. The existence of echoes implies the modification of geometry inside the photon sphere.

Bimanual coordination is essential for many spaceflight tasks, yet the effects of altered gravity on its behavioral and neural underpinnings remain unclear. This study examined the influence of microgravity (0 g) and partial gravity (0.25-0.75 g) on isometric bimanual coordination during parabolic flight. Participants performed rhythmic force tasks while force and electromyography (EMG) data were collected. Results indicated that mean force and force smoothness differed across gravity conditions, with the most pronounced behavioral impairments occurring in microgravity. Performance under partial gravity (0.25-0.75 g) generally trended toward the 1 g condition. At the neural level, exploratory EMG-EMG cross-wavelet analysis indicated reduced beta band (13-30 Hz) interlimb coordination in 0 g compared with 1 g, whereas traditional coherence measures did not show differences related to gravity. These neural findings should be interpreted cautiously and as exploratory rather than confirmatory. The findings suggest that the absence of gravitational loading is associated with the greatest challenges for coordinated motor output, while partial loading may help preserve performance. These results have implications for astronaut training and countermeasure development for future lunar and Martian missions.

Thermodynamics of Schwarzschild black hole surrounded by quintessence in the presence of quantum gravity effects in the GUP and EGUP frameworks

In future space-borne gravitational wave (GW) observations, matter around the sources might influence the evolution and GW signals from binary black hole (BBH) inspirals, which can be mistaken as deviations from general relativity (GR). Former research Phys. Rev. D 111 (2025) 104050 proposed a statistic F that characterizes the dispersion of measured parameters to distinguish environmental effect (dynamical friction (DF) from dark matter (DM) spike) and theory of modified gravity effect (varying G). In this work we use the statistic to distinguish other pairs of effects with GW corrections at -4 PN order: DF from DM spike and the extra dimension theory, additionally determine a proper distinguishing threshold via Receiver Operating Characteristic Curve (ROC) curve method to avoid arbitrariness, especially when the two effects to compare have more overlap in the F distribution. Sources of different astronomical models are also considered, and two effects are still distinguishable but less than the example in former work Phys. Rev. D 111 (2025) 104050, so the threshold should be carefully selected. Following these procedures, we finally obtain the statistic thresholds of distinguishment between the three effects with GW corrections at -4 PN order: DF from DM spike, the extra dimension theory, and varying G theory. So each effect corresponds to its own interval of the statistic F, then future observation of F can pick the preferred effect. The method can be used to distinguish other effects among environmental effects and modified theories of gravity effects with the detection of GW events.

Investigation of droplet dynamics in the hypermonotectic succinonitrile-water system in a temperature gradient and microgravity conditions supported by deep learning computer vision.

Study region: Lhasa Superconducting Gravimeter (SG) Observatory, Lhasa River alluvial plain Study focus: The Lhasa SG Observatory is the only continuously operating SG station on the Tibetan Plateau. Surrounded by thick Quaternary sediments, this site provides a critical window into the interactions between tectonic processes and hydrological mass redistribution. Precisely isolating gravity interference caused by local groundwater storage changes is essential for detecting subtle geodynamic signals, such as crustal thickening. We integrated high-precision SG observations, meteorological forcing, and in-situ groundwater levels (2010–2020) into a 1D physically-based Richards equation framework. We reconstructed the spatiotemporal evolution of soil moisture within the 3-meter unsaturated zone to accurately quantify the gravity effects induced by localized hydrological dynamics. New hydrological insights for the region: The physical model’s reconstruction exhibits strong consistency with SG residuals at an hourly scale (cross-correlation coefficient: 0.62), significantly outperforming global hydrological products like ERA5 (0.18) and GLDAS (0.55). Groundwater-induced gravity fluctuations reach an amplitude of 10.62 μGal (1 μGal = 1⋅10−8 m s− 2), sufficient to mask contemporaneous tectonic signatures. Crucially, long-term regression identifies a persistent gravity decline of approximately –0.27 ± 0.002 μGal·a⁻¹ driven by continuous groundwater depletion. This trend accounts for nearly 14 %–40 % of the observed absolute gravity variation rate. Neglecting station-scale hydrological corrections can thus lead to substantial misjudgments of crustal thickening rates and Moho subsidence magnitudes on the Tibetan Plateau.

Abstract Quantum entanglement, as one of the fundamental concepts in quantum mechanics, has garnered significant attention over the past few decades for its extraordinary nonlocality. With the advancement of quantum technology, quantum entanglement holds promising applications for exploring fundamental physical theories. The experimental scheme of Quantum Gravity Induced Entanglement of Masses (QGEM) was proposed to investigate the quantum effects of gravity based on the Local Operations and Classical Communication (LOCC) theory. In this study, we analyze the quantum properties of the entangled final states generated in the QGEM scheme. Our findings reveal that the photon emission rates (transition rates) are closely related to the degree of entanglement. Specifically, the transition rate decreases as the degree of entanglement increases when the particle separation is small, then it gradually approaches an asymptotic value that is independent of entanglement as the distance increases. We then discuss the possibility of using photon emission rates to detect quantum entanglement leveraging these results.

Spaceflight-induced cardiac atrophy and rhythm disorders are linked to dysregulation of the adrenergic-cAMP-PKA pathway. Gravity-dependent alterations in adrenergic signaling, particularly cAMP dynamics, remain poorly understood. Using fluorescence biosensors, we studied intact cells under simulated microgravity and hypergravity. We observed shifts in the EC50 of cAMP production: leftward under hypergravity and rightward in microgravity, with faster cAMP accumulation kinetics in hypergravity. Cytoskeletal remodeling, hypothesized to be a determinant of such changes, was negligible, suggesting alternative mechanisms. These findings highlight significant gravity-induced offsets in the pharmacology of a prototypical G protein-coupled receptor, with implications not only for adrenergic signaling but also for other pathways of pharmacological interest, potentially informing countermeasures for astronaut health and pharmacology in altered gravity settings.