Gradient Strength Research Articles

Dielectrophoretic separation of a water-in-oil emulsion

Electric field-assisted separation is considered one of the most effective ways of dehydrating water-in-oil emulsions. In the uniform electric field usually used in electrodehydrators, electrocoalescence leads to droplet enlargement, thus accelerating their gravitational settling. Meanwhile, using a nonuniform field is expected to provide an additional tool for phase spatial separation due to dielectrophoresis while keeping the conditions favorable for electrocoalescence. This study aims to investigate experimentally the dynamics of water-in-oil emulsion in a nonuniform electric field and the efficiency of its separation due to the dielectrophoretic effect. A high-frequency field and emulsions with zero-density contrast were used allowing us to study the action of the dielectrophoretic force in the absence of electrokinetic phenomena and gravitational settling. We found that droplets always move towards the electric field strength gradient, eventually accumulating at the internal electrode. We demonstrate that the separation efficiency increases as the average droplet size, the voltage, the dispersion medium permittivity, and the initial droplet concentration increase. In the latter case the separation enhancement is due primarily to droplet coalescence, the rate of which increases appreciably with increasing concentration. We demonstrate that all the experimental results can be combined into unified dependence based on a simple physical model.

Assessment of Tumor Cell Invasion and Radiotherapy Response in Experimental Glioma by Magnetic Resonance Elastography.

Gliomas are highly invasive brain neoplasms. MRI is the most important tool to diagnose and monitor glioma but has shortcomings. In particular, the assessment of tumor cell invasion is insufficient. This is a clinical dilemma, as recurrence can arise from MRI-occult glioma cell invasion. Tumor cell invasion, tumor growth and radiotherapy alter the brain parenchymal microstructure and thus are assessable by diffusion tensor imaging (DTI) and MR elastography (MRE). Experimental, animal model. Twenty-three male NMRI nude mice orthotopically implanted with S24 patient-derived glioma cells (experimental mice) and 9 NMRI nude mice stereotactically injected with 1 μL PBS (sham-injected mice). 2D and 3D T2-weighted rapid acquisition with refocused echoes (RARE), 2D echo planar imaging (EPI) DTI, 2D multi-slice multi-echo (MSME) T2 relaxometry, 3D MSME MRE at 900 Hz acquired at 9.4 T (675 mT/m gradient strength). Longitudinal 4-weekly imaging was performed for up to 4 months. Tumor volume was assessed in experimental mice (n = 10 treatment-control, n = 13 radiotherapy). The radiotherapy subgroup and 5 sham-injected mice underwent irradiation (3 × 6 Gy) 9 weeks post-implantation/sham injection. MRI-/MRE-parameters were assessed in the corpus callosum and tumor core/injection tract. Imaging data were correlated to light sheet microscopy (LSM) and histology. Paired and unpaired t-tests, a P-value ≤0.05 was considered significant. From week 4 to 8, a significant callosal stiffening (4.44 ± 0.22 vs. 5.31 ± 0.29 kPa) was detected correlating with LSM-proven tumor cell invasion. This was occult to all other imaging metrics. Histologically proven tissue destruction in the tumor core led to an increased T2 relaxation time (41.65 ± 0.34 vs. 44.83 ± 0.66 msec) and ADC (610.2 ± 12.27 vs. 711.2 ± 13.42 × 10-6 mm2/s) and a softening (5.51 ± 0.30 vs. 4.24 ± 0.29 kPa) from week 8 to 12. Radiotherapy slowed tumor progression. MRE is promising for the assessment of key glioma characteristics. NA TECHNICAL EFFICACY: Stage 2.

Age-related alterations in human cortical microstructure across the lifespan: Insights from high-gradient diffusion MRI.

The human brain undergoes age-related microstructural alterations across the lifespan. Soma and Neurite Density Imaging (SANDI), a novel biophysical model of diffusion MRI, provides estimates of cell body (soma) radius and density, and neurite density in gray matter. The goal of this cross-sectional study was to assess the sensitivity of high-gradient diffusion MRI toward age-related alterations in cortical microstructure across the adult lifespan using SANDI. Seventy-two cognitively unimpaired healthy subjects (ages 19-85 years; 40 females) were scanned on the 3T Connectome MRI scanner with a maximum gradient strength of 300mT/m using a multi-shell diffusion MRI protocol incorporating 8 b-values and diffusion time of 19 ms. Intra-soma signal fraction obtained from SANDI model-fitting to the data was strongly correlated with age in all major cortical lobes (r = -0.69 to -0.60, FDR-p < 0.001). Intra-soma signal fraction (r = 0.48-0.63, FDR-p < 0.001) and soma radius (r = 0.28-0.40, FDR-p < 0.04) were significantly correlated with cortical volume in the prefrontal cortex, frontal, parietal, and temporal lobes. The strength of the relationship between SANDI metrics and age was greater than or comparable to the relationship between cortical volume and age across the cortical regions, particularly in the occipital lobe and anterior cingulate gyrus. In contrast to the SANDI metrics, all associations between diffusion tensor imaging (DTI) and diffusion kurtosis imaging metrics and age were low to moderate. These results suggest that high-gradient diffusion MRI may be more sensitive to underlying substrates of neurodegeneration in the aging brain than DTI and traditional macroscopic measures of neurodegeneration such as cortical volume and thickness.

The velocity-space signature of transit-time damping

Transit-time damping (TTD) is a process in which the magnetic mirror force – induced by the parallel gradient of magnetic field strength – interacts with resonant plasma particles in a time-varying magnetic field, leading to the collisionless damping of electromagnetic waves and the resulting energization of those particles through the perpendicular component of the electric field, $E_\perp$ . In this study, we utilize the recently developed field–particle correlation technique to analyse gyrokinetic simulation data. This method enables the identification of the velocity-space structure of the TTD energy transfer rate between waves and particles during the damping of plasma turbulence. Our analysis reveals a unique bipolar pattern of energy transfer in the velocity-space characteristic of TTD. By identifying this pattern, we provide clear evidence of TTD's significant role in the damping of strong plasma turbulence. Additionally, we compare the TTD signature with that of Landau damping (LD). Although they both produce a bipolar pattern of phase-space energy density loss and gain about the parallel resonant velocity of the Alfvénic waves, they are mediated by different forces and exhibit different behaviours as the perpendicular velocity $v_\perp \to 0$ . We also explore how the dominant damping mechanism varies with ion plasma beta $\beta _i$ , showing that TTD dominates over LD for $\beta _i &gt; 1$ . This work deepens our understanding of the role of TTD in the damping of weakly collisional plasma turbulence and paves the way to seek the signature of TTD using in situ spacecraft observations of turbulence in space plasmas.

Enhanced Efficiency of Solar Wind Electron Interaction with Whistlers Caused by Switchback-related Magnetic Dips

Through test particle simulations based on solar wind observations by the Parker Solar Probe (PSP) mission, we demonstrate that a magnetic gradient can significantly enhance the efficiency of scattering and energization of the strahl electrons by quasi-parallel whistlers, through the phase trapping effect due to the gyrosurfing mechanism. We identify quasi-linear and nonlinear regimes of these interactions for different combinations of wave amplitude (B w /B 0) and the strength of the magnetic field gradient with magnetic field depletion level (B h /B 0) as a proxy. Nonlinear effects are observed for B w /B 0 ≳ 10−3 and B h /B 0 ≳ 0.1. We estimated the extending of the resonant energy range due to the wave and the magnetic field gradient interplay and demonstrated that these mechanisms result in the broadening of the strahl electron pitch-angle distribution typically observed in situ. The combination of parallel whistlers collocated with a magnetic gradient is frequently observed by PSP in magnetic dips at the edges of magnetic switchbacks. Our results indicate that these mechanisms may be highly relevant for pitch-angle scattering of the strahl electrons and regulating the heat flux near the Sun at heliocentric distances of 30–45 R S . Specifically, core and halo electrons may experience a 10% increase in their initial energy, and the majority of strahl electrons may be scattered (by an average of 30°) into the hot and trapped plasma inside magnetic dips.

Wind gradient exploitation during foraging flights by black skimmers (Rynchops niger).

Birds commonly exploit environmental features such as columns of rising air and vertical windspeed gradients to lower the cost of flight. These environmental subsidies may be especially important for birds that forage via continuous flight, as seen in black skimmers. These birds forage through a unique behavior, called skimming, where they fly above the water surface with their mandible lowered into the water, catching fish on contact. Thus, their foraging flight incurs costs of moving through both air and water. Prior studies of black skimmer flight behavior have focused on reductions in flight cost due to ground effect, but ignored potential beneficial interactions with the surrounding air. We hypothesized a halfpipe skimming strategy for skimmers to reduce the foraging cost by taking advantage of the wind gradient, where the skimmers perform a wind gradient energy extraction maneuver at the end of a skimming bout through a foraging patch. Using video recordings, wind speed and wind direction measurements, we recorded 70 bird tracks over 4days at two field sites on the North Carolina coast. We found that while ascending, the skimmers flew more upwind and then flew more downwind when descending, a pattern consistent with harvesting energy from the wind gradient. The strength of the wind gradient and flight behavior of the skimmers indicate that the halfpipe skimming strategy could reduce foraging cost by up to 2.5%.

Influence of Time-Varying Freestream Conditions on the Dynamics of Unsteady Boundary-Layer Separation

Unsteady flow separation of a turbulent boundary layer under dynamic pressure gradients is investigated using the Large-Eddy Simulation technique. The unsteadiness is introduced by prescribing an oscillating freestream vertical-velocity profile at the top boundary of the domain. Although previous studies, including Ambrogi et al. (Journal of Fluid Mechanics, Vol. 945, Aug. 2022, p. A10) and Ambrogi et al. (Journal of Fluid Mechanics, Vol. 972, Oct. 2023, p. A36), focused on the kinematics of the flow and the effects of the oscillation frequency on flow separation, the goal of this paper is to analyze the effects of three time-varying freestream-forcing profiles while the oscillation frequency is kept the same for all Cases. Whereas in Case A the freestream-velocity profile changes from suction–blowing to blowing–suction in a complete cycle, Cases B and C are both suction–blowing only and the strength of the adverse pressure gradient is modulated in time. Moreover, the boundary layer in Case B never approaches a zero-pressure gradient condition. A closed separation bubble is formed for all Cases; however, its dimensions change depending on the far-field forcing. The time evolution of turbulent kinetic energy (TKE) reveals an advection mechanism of turbulent structures out of the domain for all Cases. Whereas in Case A and C the high-TKE region, generated in the separated shear layer, is washed out of the domain as a rigid body, in Case B the separation bubble remains present and the advection mechanism of TKE is characterized by a breathing pattern.

Trueness and fit of complete-arch implant-supported frameworks in new-generation additively and subtractively manufactured polymers: An in-vitro study.

There is limited knowledge on the fabrication trueness and fit of additively or subtractively manufactured complete-arch implant-supported frameworks in recently introduced polymers. To evaluate the trueness and marginal fit of additively or subtractively manufactured polymer-based complete-arch implant-supported frameworks, comparing with those of strength gradient zirconia frameworks. A typodont model with 4 implants (left first molar (abutment 1), left canine (abutment 2), right canine (abutment 3), and right first molar (abutment 4)) was digitized (ATOS Core 80 5MP) and an implant-supported complete-arch framework was designed. This design file was used to fabricate frameworks from 5 different materials: strength gradient zirconia (SM-ZR), high impact polymer composite (SM-CR), nanographene-reinforced PMMA (SM-GR), PMMA (SM-PM), and additively manufactured temporary resin (AM) (n = 10). These frameworks were digitized and each scan file was virtually segmented into 4 regions (abutments, occlusal, overall without occlusal, and overall). The surface deviations at these regions, and linear and interimplant distance deviations were evaluated (Geomagic Control X). Marginal gaps were evaluated according to triple-scan protocol after seating frameworks on the model with the 1-screw test. Data were statistically analyzed (α = 0.05). Surface deviations of all regions differed among tested materials (p ≤ 0.001). AM frameworks mostly had surface deviations that were similar to or lower than those of other materials (p ≤ 0.031), except for the occlusal surface, where it mostly had higher deviations (p ≤ 0.013). Abutment 4 of SM-CR had higher linear deviations than abutment 2 (p = 0.025), and material type did not affect the linear deviations within abutments (p ≥ 0.171). Interimplant distance deviations differed within and among materials (p ≤ 0.017), except for those between abutments 1 and 2 among materials (p = 0.387). Marginal gaps of subtractively manufactured materials differed among abutments, while those of abutments 3 and 4 differed among materials (p ≤ 0.003). AM frameworks mostly had lower marginal gaps at abutments 3 and 4 (p ≤ 0.048). Although there was no clear trend among tested materials for measured deviations, marginal gaps of additively manufactured resin were mostly lower than those of subtractively manufactured materials and did not differ among abutment sites. Nevertheless, the differences in measured deviations among materials were small and marginal gaps were within the previously reported acceptability thresholds.

Effects of aging on the microstructure and mechanical properties of metastable β-type Ti-23.6Nb-5.1Mo-6.7Zr alloy with low elastic modulus

In this study, the influence of thermomechanical treatments on the microstructure and mechanical properties of a new metastable β-titanium Ti-23.6Nb-5.1Mo-6.7Zr alloy was assessed. The objective was to determine if the alloy is a potential candidate for a future fabrication of orthopedic implants, in particular prosthetic hip stems with a functional gradient of mechanical properties. Two thermomechanical processing routes were investigated: (a) 90% cold-rolled, (b) 90% cold-rolled, followed by annealing at 950 °C for 1 h. After these initial processing steps, samples were aged between 300 °C and 500 °C from 0.5 h to 4 h. Microstructural characterization was conducted by optical microscopy, transmission electron microscopy and x-ray diffraction. Young's modulus and microhardness were measured. Young's modulus of the sample annealed after cold rolling is lower than that after the cold rolled one. Aging was effective at increasing hardness but also increasing Young's modulus. The hardening during aging resulted from fine ωiso and α precipitation. The transmission electron microscopy investigations indicated that an aging treatment at 500 °C leads to a fine (α + β) microstructure, avoiding brittle ωiso precipitation. For these reasons, this alloy is a potential candidate for the manufacture of a hybrid hip prosthetic stem by employing localized aging treatment at 500 °C in the neck region, creating a functional strength gradient and maintaining a low Young's modulus in the distal part, which is needed to mitigate the stress shielding of the bone.

Bi-planar magnetic stabilisation coils for an inertial sensor based on atom interferometry

Inertial sensors that measure the acceleration of ultracold atoms promise unrivalled accuracy compared to classical equivalents. However, atomic systems are sensitive to various perturbations, including magnetic fields, which can introduce measurement inaccuracies. To address this challenge, we have designed, manufactured, and validated a magnetic field stabilisation system for a quantum sensor based on atom interferometry. We solve for the magnetic field generated by surface currents in-between a pair of bi-rectangular coils and approximate the surface current using discrete wires. The wires are wound by-hand onto machined panels which are retrofitted onto the existing mounting structure of the sensor without interfering with any experimental components. Along the central 60mm of the y-axis, which aligns with the trajectory of the atoms during interferometry, the coils are measured to generate an independent uniform axial magnetic field with a strength of Bz=22.81±0.01μT/A [mean±2σstd. error] and an independent linear axial field gradient of strength dBz/dy=10.6±0.1μT/Am. The uniform Bz field is measured to deviate by a maximum value of 1.3% in the same region, which is a factor of three times more uniform than the previously-used on-sensor rectangular Bz compensation set.

Factors influencing diffusion tensor imaging of knee cartilage in children ages 6-12years: a prospective study.

Magnetic resonance diffusion tensor imaging (DTI) has recently been used to evaluate the developing cartilage of children, but the influencing factors have not been well studied. The objective of this study was to investigate the influence of the diffusion gradient strength (b value), diffusion gradient direction, age and sex on knee cartilage DTI in healthy children aged 6-12years. A total of 30 healthy child volunteers, with an average age of 8.9 ± 1.6 (mean ± standard deviation) years, were enrolled in this study. They were categorized into three groups according to their age range: 6-8years, 8-10years and 10-12years, ensuring equal sex distribution in each group (5 boys and 5 girls). These volunteers underwent routine left knee joint magnetic resonance imaging (MRI) and serial DTI scans. DTI parameters were altered as follows: when b value = 600s/mm2, diffusion gradient direction was set to 6, 15, 25, 35 and 45; and when diffusion gradient direction = 25, b value was set to 300, 600, 900 and 1200s/mm2. The values of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were separately acquired using image post-processing techniques. The correlation between various b values, diffusion gradient directions, age and sex on the one hand and FA and ADC values on the other, was investigated. (1) When diffusion gradient direction was fixed and the b value was varied, both FA and ADC exhibited a decreasing trend as the b value increased (P < 0.001). (2) When the b value was fixed and diffusion gradient direction was varied, the FA of knee cartilage showed a decreasing trend with increasing diffusion gradient direction (P < 0.001). (3) The FA value increased with age (P < 0.05). The b value, diffusion gradient direction value and age exert a significant impact on both FA and ADC values in MR DTI of knee cartilage in children aged 6-12years. In order to obtain a stable DTI, it is recommended to select a b value ≥ 600s/mm2 and a diffusion gradient direction ≥ 25 during scanning.

Features of the strength abilities of the world's leading armwrestlers weighing 80-100 kg

Purpose: determination of the main components of power capabilities that ensure the success of the competitive exercise of armwrestlers weighing 80-100 kg. Material and Methods. The study involved 4 best armwrestlers in the world weighing from 80 to 100 kg (m = 87.50 ± 2.47 kg) in 2017–2020: athlete 1 is a multiple world champion weighing 90 kg (Ukraine), athlete 2 is a multiple champion world champion weighing 82 kg (Ukraine), athlete 3 - multiple world champion weighing 93 kg (Ukraine), athlete 4 - multiple winner of international competitions weighing 85 kg (USA). During the study, strength indicators were determined in 4 competitive exercises. Strength indices in all test exercises were measured in a static mode by an FB5k series electrical tenzodynamometer (Poland) with an accuracy class of up to 100 g, which was mounted on a special armwrestling table using a specially made block device. The created design was called the “ARM1 Device” (patent 43082). During the statistical analysis, the following parameters were calculated: maximum and relative strength, total strength index in four strength exercises (F), time to reach maximum strength (t), speed-strength index (F/t), average strength index of four exercises (F/4), gradient of the total strength of four exercises (t0,5F), strength index in the first 100 ms and 500 ms, speed-strength index in the first 500 ms (F500/t500), hour of reaching a force of 1 kg (t0,5F/(0,5×F); Pearson correlation analysis. Results. As a result of the study, the main data on the speed-strength indicators of armwrestlers were obtained and analyzed. In the process of testing, according to the indicators of time periods and given efforts of dynamic strength, the features of the manifestation of the explosive, fast and slow strength of arm wrestlers 80-100 kg were established. Conclusions. The study made it possible to establish indicators of the speed-strength index, strength gradient, the ability to manifest dynamic strength in the first 500 ms, clearly characterizing the speed-strength capabilities of armwrestlers and allowing to determine the features and nature of the manifestation of their dynamic strength. This makes it possible to determine the natural ability to manifest dynamic strength, as well as to select and predict the performance of promising athletes, to specify the direction and content of the training process, and to clarify the program of participation in competitions.

Numerical analysis of downward progressive landslides in long natural slopes with sensitive clay

Landslides occurring in sensitive clay often result in widespread destruction, posing a significant risk to human lives and property due to the substantial decrease in undrained shear strength during deformation. Assessing the consequences of these landslides is challenging and necessitates robust numerical methods to comprehensively investigate their failure mechanisms. While studies have extensively explored upward progressive landslides in sensitive clays, understanding downward progressive cases remains limited. In this study, we utilised the nodal integration-based particle finite element method (N-PFEM) with a nonlinear strain-softening model to analyse downward progressive landslides in sensitive clay on elongated slopes, induced by surcharge loads near the crest. We focused on elucidating the underlying failure mechanisms and evaluating the effects of different soil parameters and strain-softening characteristics. The simulation results revealed the typical pattern for downward landslides, which typically start with a localised failure in proximity to the surcharge loads, followed by a combination of different types of failure mechanisms, including single flow slides, translational progressive landslides, progressive flow slides, and spread failures. Additionally, inclined shear bands occur within spread failures, often adopting distinctive ploughing patterns characterised by triangular shapes. The sensitive clay thickness at the base, the clay strength gradient, the sensitivity, and the softening rate significantly influence the failure mechanisms and the extent of diffused displacement. Remarkably, some of these effects mirror those observed in upward progressive landslides, underscoring the interconnectedness of these phenomena. This study contributes valuable insights into the complex dynamics of sensitive clay landslides, shedding light on the intricate interplay of factors governing their behaviour and progression.

Specific changes in contractive functions and skeletal muscle architecture in humans in response to the use of two protocols of unmodulated neuro-muscular electrostimulation

The purpose of this study was to study the effect of unmodulated low-frequency superficial of neuromuscular electrical stimulation (NMES) of 30 and 60 min/day for 7 weeks on the force, velocity-strength properties of the triceps surae muscle (TS) and architecture (lengths and angles of fascicles) of human the medial gastrocnemius muscle (MG). Many studies have examined the effect of training intensity (percentage of maximal voluntary isometric contraction — MVC) during NMES on muscle force response. However, no study has examined the effect of the number of NMES sessions per day over 7 weeks on changes in the TS strength. Ten healthy volunteers (23.2 ± 3.2 years; age range 18–28 years) volunteered for the study and were randomly assigned to group 1 (30 min NMES) and group 2 (60 min NMES) 5 times a day. NMES for a 7-week period, a total of 35 NMES workouts Isometric triceps calf strength was recorded with a Biodex isokinetic dynamometer. The longitudinal ultrasonic images of the MG was measured in vivo using the B-mode Edge ultrasound system. After a 7-week training period, MVC and voluntary maximal “explosive” strength differed significantly between groups. Based on electrical stimulation parameters and healthy subjects in this study, electrical training caused an increase in foot extensor muscle strength and a gradient in voluntary explosive strength when used for 5 training per week for 30 min for 7 weeks.

Permeability and strength of gradient printed permeable steel manufactured by selective laser melting

Based on the forming principle of laser rapid melting and layered manufacturing, the selective laser melting (SLM) process is suitable for the preparation of permeable metal materials with a certain porosity. One of the important applications of this special structure is the development of permeable steel. In this study, the permeable steel with micron-sized controllable pores was prepared by gradient printing using SLM process. The formation and connectivity mechanism of pore structure were analyzed by adjusting the interlayer arrangement of scanning melt channels, and the influence of process parameters on the pore characteristics, permeability and mechanical properties was systematically investigated. The results revealed that the porosity and pore size of permeable steel were effectively improved by controlling the hatch distance and scanning strategy, with the results ranging from 7.81 % to 17.32 % and 57 μm to 121 μm, respectively. Based on the gas permeation test, it was verified that the permeability of permeable steel showed a clear upward trend with increasing porosity, and the results ranged from 2.17 × 10−12 m2 to 4.26 × 10−12 m2, indicating that the pore structure provides a strong basis for gas flow. Moreover, the mechanical properties of permeable steel decreased significantly with the increase of porosity and pore size, and the compressive strength and tensile strength ranged from 1061 MPa to 528 MPa and 1018 MPa to 609 MPa, respectively. The mechanical behavior and deformation mechanism were closely related to the gradient evolution of the pore structure. Overall, the gradient printed permeable steel using SLM process has good permeability and mechanical properties.

A Rapid Localization Method Based on Super Resolution Magnetic Array Information for Unknown Number Magnetic Sources.

A rapid method that uses super-resolution magnetic array data is proposed to localize an unknown number of magnets in a magnetic array. A magnetic data super-resolution (SR) neural network was developed to improve the resolution of a magnetic sensor array. The approximate 3D positions of multiple targets were then obtained based on the normalized source strength (NSS) and magnetic gradient tensor (MGT) inversion. Finally, refined inversion of the position and magnetic moment was performed using a trust region reflective algorithm (TRR). The effectiveness of the proposed method was examined using experimental field data collected from a magnetic sensor array. The experimental results showed that all the targets were successfully captured in multiple trials with three to five targets with an average positioning error of less than 3 mm and an average time of less than 300 ms.

Prioritizing Environmental Attributes to Enhance Residents’ Satisfaction in Post-Industrial Neighborhoods: An Application of Machine Learning-Augmented Asymmetric Impact-Performance Analysis

Post-industrial neighborhoods are valued for their historical and cultural significance but often contend with challenges such as physical deterioration, social instability, and cultural decay, which diminish residents’ satisfaction. Leveraging urban renewal as a catalyst, it is essential to boost residents’ satisfaction by enhancing the environmental quality of these areas. This study, drawing on data from Shenyang, China, utilizes the combined strengths of gradient boosting decision trees (GBDTs) and asymmetric impact-performance analysis (AIPA) to systematically identify and prioritize the built-environment attributes that significantly enhance residents’ satisfaction. Our analysis identifies twelve key attributes, strategically prioritized based on their asymmetric impacts on satisfaction and current performance levels. Heritage maintenance, property management, activities, and heritage publicity are marked as requiring immediate improvement, with heritage maintenance identified as the most urgent. Other attributes are categorized based on their potential to enhance satisfaction or their lack of immediate improvement needs, enabling targeted and effective urban revitalization strategies. This research equips urban planners and policymakers with critical insights, supporting informed decisions that markedly improve the quality of life in these distinctive urban settings.

Optical phase and amplitude measurements of underwater turbulence via self-heterodyne detection

The creation of underwater optical turbulence is driven by density variations that lead to small changes in the water’s refractive index, which induce optical path length differences that affect light propagation. Measuring a laser beam’s optical phase after traversing these turbulent variations can provide insight into how the water’s turbulence behaves. The sensing technique to measure turbulent fluctuations is a self-heterodyne beatnote enhanced by light’s orbital angular momentum (OAM) to obtain simultaneous optical phase and amplitude information. Experimental results of this method are obtained in a water tank that creates a thermally driven flow called Rayleigh–Bénard (RB) convection. The results show time-varying statistics of the beatnote that depend on the incident OAM mode order and the strength of the temperature gradient. Beatnote amplitude and phase power spectral densities are compared to analytic theory to obtain estimates of the turbulent length scales using the Taylor hypothesis that include mean flow speed, turbulent strength, and length scales, and flow dynamics due to intermittency in the RB process.

Silicon regulation of the interface microstructure and shear strength of rheological cast-rolling aluminum/steel composite plates

This study reports the preparation of medium-thickness aluminum/steel composite plates with different diffusion layers using rheological cast-rolling technology. The thermodynamic software and first-principles were employed to determine the effects of different silicon contents on the solidification process and mechanical properties of the 6061 aluminum/steel composite plates. The research revealed that the Fe2Al5 phase on the steel side possessed a tongue-like preferential growth at a silicon content of less than 1.2 wt%. A granular Al–Fe–Si phase was formed on the aluminum side of the diffusion layer when the silicon content exceeded the saturation solubility (1.8 wt%), which completely suppressed the tongue-like preferential growth of the Fe2Al5 phase. First-principles calculations revealed that the matrixes showed superior toughness in comparison to binary intermetallic compounds (IMCs), while the toughness of binary IMCs surpassed that of ternary IMCs. The mechanical properties showed that the shear strength of the sample prepared by rheological cast-rolling was higher than that of composite casting and close to that of composite rolling, reaching a maximum value of 73.4 MPa. The shear strength initially increased and then decreased with an increase in isothermal diffusion time, and the fracture location was transferred from the loose FeAl3 to the Fe2Al5 phase. An increase in silicon content resulted in a slight increase in the microhardness of the diffusion layer, a delay of the peak value of the shear strength, and a reduction in the gradient of the shear strength. A substantial decrease in peak shear strength was observed when the silicon content reached 1.8 wt%.

Numerical modelling of downward progressive landslides in sensitive clay

Landslides in sensitive clays are catastrophic events that threaten life and property. When plastic strain occurs in sensitive clays, there is a significant reduction in the undrained shear strength. Consequently, even minor triggers can lead to multiple progressive landslides, causing extensive devastation. Investigating landslides in sensitive clay presents challenges, necessitating robust numerical methods to comprehend failure modes and collapse behaviors, particularly in the post-failure phase. Although several numerical methods have been utilized for simulations, most have primarily focused on upward progressive landslides. In this study, we adopted the nodal integration-based particle finite element method to simulate downward progressive landslides triggered by surcharge loads from an embankment near the crest in sensitive clay on a long slope. We also considered nonlinear strain softening in sensitive clays. The effects of the strain softening rate and strength gradient of the sensitive clay layer on the failure mechanisms and destruction extent were investigated. The simulation results reveal that a downward progressive landslide initiates with a localized flow slide surrounding the embankment and usually involves a combination of various failure modes.