Surface Stress Research Articles

Research on reasonable coal pillar staggered distance in shallow multi-seam mining

In shallow buried closely spaced multi-seam mining in Jurassic Coalfield in western China, due to specific reasons, it is inevitable that the lower and upper coal seam working faces and coal pillars are overlapped, resulting in stress concentration, uneven subsidence of the ground surface, the deformation and damage of the roadway intensified. In order to decrease surface damage and stress concentration, combined with physical simulation, engineering practices and theoretical analyses, reasonable coal pillar staggered distance in shallow multi-seam mining is investigated. The evolution properties of three-field (stress field, displacement field and fracture field) based on coal pillar staggered distance (CPSD) were analyzed, the determination method of rational CPSD was put up. Research findings reveal that concentrated stress results from upper and lower pillar stress superposition, and the lower pillar should be arranged in the low-stress zone. Through rational pillar arrangement, the uneven subsidence of surface is reduced, and the concentrated fractures of overlying strata and surface are decreased. For No. 1–2 and No. 2–2 coal seam mining, as CPSD is increased, subsidence above the upper coal pillar increases and the uneven subsidence of surface decreases, the concentrated stress reduced by 25%, the width of surface fractures reduced 81.1%. Consequently, rational CPSD on the basis of coupling control of three-field can be determined, the reasonable CPSD is 40–55 m. It can provide a method to realize underground safe mining and ground surface green mining in shallow multi-seam mining.

A review of thermal shock behavior of ceramics: Fundamental theory, experimental methods, and outlooks

AbstractThe thermal shock resistance of ceramics is a key factor for determining the durability of ceramic components under transient thermal conditions and is also one of the key factors for evaluating the stability of ceramics under extreme thermal conditions. After rapid heating or cooling, the surface and internal thermal stress mismatches of ceramics can cause severe thermal damage. Two main types of ceramic thermal shock exist: rapid cooling and rapid heating thermal shock. This article presents a broad understanding and insight into fundamental theory and experimental methods for ceramic thermal shock testing. The experimental equipment and procedures, test result evaluation, and material characterization of ceramic thermal shock are summarized. Moreover, outlooks and perspectives are discussed for testing and characterizing ceramic thermal shock resistance. This review will be helpful to researchers performing studies in the relevant fields of ceramics.

Interannual Variation of Summer Sea Surface Salinity in the Dotson–Getz Trough, West Antarctica

In this study, we explore the interannual variability of Sea Surface Salinity (SSS) in the Dotson–Getz Trough located in West Antarctica, focusing on the month of February. Utilizing the oceanic analysis product EN4, we first validate the EN4 SSS with data from a singular ship-based survey, and then delve into potential factors that may influence SSS, with a particular emphasis on surface freshwater flux, sea ice concentration (SIC), and also the surface stress curl, which will induce upwelling via Ekman transport to affect the SSS. Our findings primarily indicate a link between SSS and sea ice concentration, showcasing a negative correlation where the peak (average) coefficient is around −0.6 (−0.4), further affirming the substantial interannual variability of SSS in this region.

Design of guided wave magnetostrictive patch transducer with vertical static bias magnetic field for pipe inspection

Compared with electromagnetic acoustic transducer (EMAT), magnetostrictive patch transducer (MPT) has higher energy conversion efficiency. MPT is often used to excite and receive long-distance ultrasonic guided waves for defect detection or structural health monitoring of large industrial equipment. In this work, a new design method of permanent magnet MPT using the vertical static bias magnetic field to excite shear horizontal (SH) guided waves is proposed. First, the mathematical model of exciting ultrasonic guided waves by a vertical static bias magnetic field MPT is established, and the equivalent surface stress in the magnetostrictive patch is calculated. It is shown that the vertical static bias magnetic field MPT can excite SH guided waves in plates. Then, the influence of static bias magnetic field intensity on the amplitude of guided wave signal is analyzed. Compared with other traditional MPTs, the amplitude of SH guided wave signal excited by the vertical static bias magnetic field MPT is increased. Finally, a periodic permanent magnet (PPM)-MPT with a central frequency of 120 kHz is designed. The proposed PPM-MPT improves the energy conversion efficiency compared to the circumferential alternating permanent magnet array type MPT. The PPM-MPT can detect defects in a steel pipe with a wall thickness of 3.5 mm and an inner diameter of 100 mm. The results show that the PPM-MPT designed in this paper successfully detects the through hole with a diameter of 2 mm, and the cross-section loss rate of the defect is about 0.6 %.

A novel flexible magnetoelastic biosensor with “sandwich” structure based on transferrin encapsulated gold nanoclusters for 5-hydroxytryptamine detection

5-hydroxytryptamine (5-HT), a mono-amine neurotransmitter, plays an important role in regulating the dynamics of neural circuits in the central nervous system and enteric nervous system. Accurate and sensitive monitoring of 5-HT will provide critical information for diagnosing many psychiatric and neurological disorders. However, there are no superior clinical assays for the detection of 5-HT, and existing methods of gas chromatographs and mass spectrometers are expensive, limiting portable and real-time monitoring as diagnostic approaches in the clinical setting. Therefore, a convenient, rapid, and low-cost method for the detection of 5-HT is still in demand in current clinical medicine. Herein, a novel flexible magnetoelastic (ME) biosensor with “sandwich” structure is proposed for 5-HT detection based on transferrin encapsulated gold nanoclusters (Tf-AuNCs). Combined with the magnetoelastic effect of CoFe2O4, the excellent conductivity of silver nanowires (AgNWs), and the fluorescence properties of Tf-AuNCs, the ME biosensor designed in this paper can achieve multi-signal recognition. Rapid and sensitive detection of 5-HT is achieved by a biosensing process that converts surface stress signal into magnetoelectric signals. The biosensor is capable of detecting 5-HT with different concentrations in a linear range of 10 ng/mL-100 μg/mL (R2 = 0.97119) with a lower detection limit (LOD) of 0.33 ng/mL. The accurate measurement results of 5-HT in human serum of clinical samples demonstrated the feasibility of the biosensor for 5-HT detection. This flexible ME biosensor was prepared in a simple process with great specificity and stability, providing a portable analytical device for the rapid and sensitive detection of 5-HT, which is of great significance for the clinical research of various neurological diseases.

Extensive Contact Lens Wear Modulates Expression of miRNA-320 and miRNA-423-5p in the Human Corneal Epithelium: Possible Biomarkers of Corneal Health and Environmental Impact.

The identification of new biomarkers of ocular diseases is nowadays of outmost importance both for early diagnosis and treatment. Epigenetics is a rapidly growing emerging area of research and its involvement in the pathophysiology of ocular disease and regulatory mechanisms is of undisputable importance for diagnostic purposes. Environmental changes may impact the ocular surface, and the knowledge of induced epigenetic changes might help to elucidate the mechanisms of ocular surface disorders. In this pilot study, we investigated the impact of extensive contact lens (CL) wearing on human corneal epithelium epigenetics. We performed ex vivo analysis of the expression of the miR-320 and miR-423-5p involved in the processes of cellular apoptosis and chronic inflammation. The human corneal epithelium was harvested from healthy patients before the photorefractive keratectomy (PRK). The patients were divided into two age- and sex-matched groups accordingly to CL wearing history with no CL wearers used as a control. The epithelium was stored frozen in dry ice at -80 °C and forwarded for miRNA extraction; afterwards, miRNA levels were detected using real-time PCR. Both miRNAs were highly expressed in CL wearers (p < 0.001), suggesting epigenetic modifications occurring in chronic ocular surface stress. These preliminary results show the relationships between selected miRNA expression and the chronic ocular surface stress associated with extensive CL use. MicroRNAs might be considered as biomarkers for the diagnosis of ocular surface conditions and the impact of environmental factors on ocular surface epigenetic. Furthermore, they might be considered as new therapeutic targets in ocular surface diseases.

Understanding the dynamics of in-situ micro-rolling in directed energy deposition using thermo-mechanical finite-element analyses

Rolling in Directed Energy Deposition (DED) has shown promising improvements in build quality by providing compressive deformations. The rolling dynamics and associated boundary conditions are crucial for how these deformations impact the stress–strain profiles on the deposited part and substrate. This study investigates these impacts by developing a fully coupled dynamic-thermo-mechanical finite-element model in Abaqus for in-situ micro-rolling in DED. Single bead analyses have been done with a 2D heat flux moving ahead of the roller at a fixed offset. Two rolling boundary condition cases with varying friction at the roller-bead interface have been examined: (i) only translation defined with rotation calculated from roller-bead interaction and (ii) translation with a defined rotation corresponding to a no-slip condition. In the first case, analyses have shown that the surface stress–strain conditions and rolling load variation are susceptible to interfacial friction. With increasing friction, the surface conditions deteriorate and variations in rolling load increase. However, beyond the surface, the overall stress–strain profiles remain similar. The surface stress–strain profile and rolling load variation have been smoothened in the second case because of the defined rotation. Further, a comparison has been made between the results of dynamic-explicit analyses and static-implicit analyses to quantify the roller’s inertia effects. The stress–strain profiles predicted by both analyses have marginal differences but with 16 % over-prediction in rolling load by dynamic-explicit analyses. These results imply that the roller’s inertia marginally affects the deposited part’s stress–strain evolution but has a notable role in rolling load. Also, providing an external drive to the roller corresponding to the second case can effectively minimise the deteriorating effects of roller-bead interfacial friction.

Surface stress redistribution and thermal performance of tempered vacuum glazing with printing sintering support pillars

The support stress distribution of the printing sintering support pillars (PSSP), which became rounded due to the shrinkage that occurred in sintering formation, was different from that of the conventional cylindrical metal support pillars (CMSP). In this paper, ANSYS software was used to establish the mechanical simulation model of tempered vacuum glazing with PSSP. The influence of PSSP arrangement (spacing D, and three arrangement styles of square, regular triangle, and regular hexagon) on the mechanical properties of tempered vacuum glazing were analyzed, including the maximum stress σ1max on tempered glass (T-glass) surface, the maximum deformation ω1max of T-glass, and the maximum stress σ2max on the PSSP. The simulation results showed that when the PSSP were arranged in a square with D of 50 mm, σ1max, ω1max, and σ2max were 26.39 MPa, 7.82 μm, and 546.72 MPa, respectively, which met the requirements of the evaluation indexes of mechanical properties of tempered vacuum glazing, and had the least number of PSSP. The mechanical properties of tempered vacuum glazing with regular triangle arrangement of PSSP were better than those of square and regular hexagon arrangements, and the σ1max, ω1max and σ2max of which were 16.24 MPa, 7.25 μm and 489.66 MPa respectively, but with a too large number of PSSP. Optimization of the triangle layout angle and side length could reduce PSSP numbers. When the PSSP were arranged in an isosceles triangle with a 65° base angle and 50 mm bottom length, the mechanical properties of tempered vacuum glazing were the best. The triangular arrangement of PSSP had an optimization effect on the surface stress redistribution of tempered vacuum glazing, and the number of stress peaks was twice that of the square arrangement. Meanwhile, tempered vacuum glazing samples were made and the surface stress, thermal conductivity tests were conducted. The results showed that the measured values of peak and valley stress had an error of ±2.8 MPa compared to the simulated values. The simulation results were reliable and the surface stress redistribution of tempered vacuum glazing was present. The measured heat transfer coefficient of tempered vacuum glazing with PSSP was 0.7402 W m−2 K−1, slightly higher than that of tempered vacuum glazing with CMSP. The difference between them was not significant.

Time-Series Analysis of Mining-Induced Subsidence in the Arid Region of Mongolia Based on SBAS-InSAR

Mongolia’s substantial mineral resources have played a pivotal role in its economic progress, with mining activities significantly contributing to this development. However, these continuous mining operations, particularly at the Oyu Tolgoi copper and gold mine, have induced land subsidence that threatens both production activities and poses risks of geological and other natural disasters. This study employs the Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technique to monitor and analyze time-series surface subsidence using 120 Sentinel-1A datasets from 2018 to 2022. The findings reveal that the SBAS-InSAR method successfully captures the subsidence and its spatial distribution at Oyu Tolgoi, with the maximum cumulative subsidence reaching −742.01 mm and the highest annual average subsidence rate at −158.11 mm/year. Key drivers identified for the subsidence include variations in groundwater levels, active mining operations, and changes in surface stress. This research underscores the ongoing subsidence issue at the Oyu Tolgoi mining area, providing crucial insights that could aid in enhancing mining safety and environmental conservation in the region.

An efficient 3D finite element procedure for simulating wheel–rail cyclic contact and ratcheting

Various models for simulating rail ratcheting behaviour were developed to study rolling contact fatigue (RCF) damage in rails. However, limitations remain in terms of the accuracy of wheel–rail contact modelling and computational efficiency of the cyclic loading simulation. This study developed an efficient 3D finite element (FE) procedure to simulate ratcheting in rails subjected to numerous load cycles. The procedure simulates a wheel rolling repeatedly over a rail section with updated stress–strain states, enabling automatically executed cyclic loading simulation given a predefined number of cycles. To ensure the accuracy of the contact modelling, the effect of meshing schemes on subsurface stress distribution was examined. In addition, the FE contact model with the selected meshing scheme, which balances accuracy and computational efficiency, was verified against the widely accepted CONTACT program. Subsequently, a non-linear kinematic hardening (NLKH) steel material was used in the FE model for ratcheting simulations with up to 100 wheel-loading cycles. The rail surface and subsurface stress states were replicated under partial-slip wheel–rail rolling contact conditions with traction coefficients of 0.10, 0.20 and 0.35, respectively. The ratcheting behaviour was extensively analysed in terms of plastic deformation, contact patch evolution, and ratcheting rates. The simulated plastic deformation was found to alter the contact geometry and thus contact stresses, which in turn affect further accumulation of plastic deformation and subsequent ratcheting strains. These findings highlighted the importance of considering the interplay between the rail ratcheting behaviour of the rail and evolving contact conditions for predicting ratcheting and RCF damage in rails.

Comparing the Mechanical Properties of Rice Cells and Protoplasts under PEG6000 Drought Stress Using Double Resonator Piezoelectric Cytometry.

Plant cells' ability to withstand abiotic stress is strongly linked to modifications in their mechanical characteristics. Nevertheless, the lack of a workable method for consistently tracking plant cells' mechanical properties severely restricts our comprehension of the mechanical alterations in plant cells under stress. In this study, we used the Double Resonator Piezoelectric Cytometry (DRPC) method to dynamically and non-invasively track changes in the surface stress (ΔS) generated and viscoelasticity (storage modulus G' and loss modulus G″) of protoplasts and suspension cells of rice under a drought stress of 5-25% PEG6000. The findings demonstrate that rice suspension cells and protoplasts react mechanically differently to 5-15% PEG6000 stress, implying distinct resistance mechanisms. However, neither of them can withstand 25% PEG6000 stress; they respond mechanically similarly to 25% PEG6000 stress. The results of DRPC are further corroborated by the morphological alterations of rice cells and protoplasts observed under an optical microscope. To sum up, the DRPC technique functions as a precise cellular mechanical sensor and offers novel research tools for the evaluation of plant cell adversity and differentiating between the mechanical reactions of cells and protoplasts under abiotic stress.

Thermal and surface properties of AlZnO and surfactant-stabilized AlZnO nanofluids: Influence of sonication duration for heat transfer applications

Research into doped metal oxide nanofluids (NFs) has intensified due to recent breakthroughs in heat transfer applications. This study explores the thermophysical properties of Aluminum Zinc Oxide (AlZnO) at a 0.10 vol% concentration and surfactant-enhanced Aluminum Zinc Oxide (f@AlZnO) at concentrations of 0.05, 0.10, and 0.20 vol%. Experiments were conducted across a temperature range from 20 to 80°C. The study utilized various analytical techniques such as FT-IR, UV–visible spectroscopy, Powder XRD, SEM, and EDX to examine the effects of volume concentration and sonication duration on stability, particle size, thermophysical properties, contact angle, wettability, and surface tension. It was found that the thermal conductivity of AlZnO and f@AlZnO NFs increases with both volumetric concentration and temperature. Notably, surfactant inclusion significantly enhanced the stability of AlZnO NFs, achieving a high zeta potential after 160 minutes of sonication. The 0.10 vol% f@AlZnO NF displayed optimal stability at this sonication duration, while the 0.10 vol% AlZnO NF showed the smallest particle size distribution after just 20 minutes. Thermal conductivity enhancements of 5 %, 2.5 %, 2 %, and 1.9 % were observed for 0.10 vol% AlZnO NF and 0.05, 0.10, and 0.20 vol% f@AlZnO NFs, respectively. Additionally, at 200 minutes of sonication, the 0.05 vol% f@AlZnO NF demonstrated the lowest increase in specific heat capacity. The study also revealed that both surfactant addition and increasing volumetric concentration of AlZnO NFs reduced surface stress and contact angle values. In contrast, dynamic viscosity and density increased with higher nanoparticle concentration and decreased with rising temperature. The Mouromtseff number calculations underscore the potential of AlZnO NFs in thermal applications, meriting further investigation. This comprehensive examination provides critical insights into the effective utilization of hybrid metal oxide NFs in heat transfer applications.

Design criteria for conformal integration of flexible electronics on advanced aircraft surfaces

This paper introduces a set of design criteria that aim to integrate flexible electronics onto three-dimensional surfaces in a mechanically adaptive manner. Previous studies have been limited to conformal integration on specific shapes (Such as spherical surfaces and corrugated surfaces) of rigid surfaces or soft substrates, there is a lack of a universal design strategy that takes into account the complexity of substrate shapes and varying hardness. To address this gap, the paper outlines a mechanical model that utilizes Hertzian contact theory to describe the interaction between the thin film and the substrate, and the conformal surface morphology and stress state were derived from minimizing the total energy of the island-substrate structure. The proposed formulations are verified through finite element methods and experiments, analyzing the effects of Young's modulus, in-plane size, and thickness of the “island” on its conformability. Therefore, this paper proposes a generic on-demand conformal design strategy that takes into account the complexity and hardness of the substrate. This study's findings will contribute to the development of conformal electronics that can be used in various fields, such as epidermal electronics, flexible robots, robot electronic skin, and aircraft smart skin.

Relation between edge stress, bending strength, surface stress and fracture pattern of thermally toughened glass

Thermally toughened safety glass must meet safety requirements in the building industry. Here, destructive tests are defined in the product standards, which must be carried out on small, standardized format (360 mm × 1100 mm) glass elements to determine the fracture pattern and bending strength. This is costly and not in the interests of sustainability. As part of the quality control of optical anisotropy effects in thermally toughened glass, isochromatic scans that can provide information on the edge stress are acquired. The evaluation of the isochromatics and retardations at the edge with deduction of the edge stress and transfer to bending strength and fracture pattern could provide essential findings for assuring the safety requirements of thermally toughened glass. In this experimental investigation, the surface and edge stress were measured on standardized format thermally toughened safety glass, with different edge processing and glass thicknesses from three different suppliers. Afterwards, the fracture pattern is controlled, or the bending strength is analyzed in a destructive four-point bending test. Conclusively, the results from the photoelastic and destructive tests are compared to determine whether the photoelastic measurement methods used to measure surface and edge stress can be employed as quality control.

Homogenized moduli and local multiphysics fields of unidirectional piezoelectric nanocomposites with energetic surfaces

The study extends the locally-exact homogenization theory (LEHT) to determine the effective parameters and localized multiphysics fields of unidirectional piezoelectric nanocomposites with energetic surfaces. The interface is simulated using the generalized Gurtin-Murdoch model for piezoelectric nanocomposites, taking into account the discontinuities between surface stresses and electrical displacement. By characterizing hexagonal and square repeating unit cells (RUC), the interactions across a fiber's or pore's interface in piezoelectric nanocomposites with energetic surfaces have been analyzed. The extended LEHT possesses the advantages of fast convergence, excellent stability, and computational efficiency due to its avoidance of mesh discretization and pointwise satisfaction of interfacial conditions. To verify the validity of the present theory, this paper also derives the Eshelby solution for piezoelectric nanocomposite with energetic surfaces. The reliability and accuracy of the present theory are demonstrated by comparing the present results from the Eshelby solution and the finite element method (FEM) with generally good agreement. On this basis, the influence of microstructural effects, such as phase volume fractions and geometrical arrangement, on the effective and local responses of piezoelectric nanocomposites with energetic surfaces are investigated. The results show that effective piezoelectric/dielectric moduli and electric displacement field for piezoelectric nanocomposites are significantly affected by the size effect, along with several other parameters such as unit cell arrays and fiber/pore volume fractions. Those results highlight the significance of neighboring pore or fiber interactions for piezoelectric nanocomposites, which are often overlooked in traditional micromechanics models and are challenging to be captured using numerical methods.

Phase-field simulation of crack propagation in particulate nanocomposite materials considering surface stresses

Phase-field simulation of crack propagation in particulate nanocomposite materials considering surface stresses

Research on the Wear Evolution Behavior of 20CrMnTi Alloy Steel under Different Loading Conditions

Abstract 20CrMnTi alloy steel has excellent surface hardness and good wear resistance, making it widely used in the preparation of key components of various high-speed and high-load gearboxes, such as gear, rack, and bearing. However, the existence of friction and wear behavior in service leads to various damage behaviors, which seriously affects its service stability and effective life. Based on experimental research and numerical simulation technology, this study reveals the damage evolution law of 20CrMnTi low carbon alloy steel under different wear load conditions. It is shown that the increase of wear load and time duration will obviously lead to the increase of contact stress and deformation of the material surface, and eventually lead to an increase in wear degree. The research findings provide experimental support and theoretical guidance for effectively predicting the damage law in actual service.

Hydrogen charging can relax compressive residual stresses caused by shot peening

Surface engineering to generate compressive stresses via processes such as shot peening is commonly employed to mitigate fracture or fatigue failures in metallic systems. Localized plastic deformation is used to generate the generally biaxial compressive elastic stresses. This study examined the residual stress conditions and local mechanical performance of medium carbon steel in a quenched and tempered state. Electrolytic hydrogen charging of peened samples led to a permanent reduction in the compressive surface stress while concurrently hardening the surface. Slight changes in elastic modulus when solute hydrogen was present could not explain the resulting change in the measured residual stress; a reduction in X-ray peak breadth suggests that the combined effects of elastic stresses and solute hydrogen caused local dislocation annihilation and re-organization of the dislocation structure in the severe plastically deformed layer, leading to a lower magnitude and shallower depth of compressive residual stress on the peened surface after hydrogen charging.

Surface effect on the partial-slip contact of a nano-sized flat indenter

The partial-slip contact at nano-scale is always influenced by a surface effect. A new model based on the Gurtin-Murdoch (G-M) surface elasticity theory is proposed in this paper to study the partial-slip contact behavior of a rigid flat nano-indenter on an elastic half-space. The surface effect in the partial-slip contact is characterized via a non-classical boundary condition involving a surface-induced normal traction related to the residual surface stress and a surface-induced tangential traction related to the surface elasticity, the influences of which on stress and displacement fields and the stick-slip state at the contact surface are investigated. It is found that, with the increase of residual surface stress, both the normal pressure and vertical and horizontal displacements in the contact zone decrease, the relative slip between indenter and substrate reduces and the stick region is enlarged. Such effects are basically attributed to the action of the surface-induced normal traction opposite to the externally applied compression. However, the increase of surface elastic constants is conductive to the relative slip and results in a shrinkage of the stick region, which is attributed to the action of the surface-induced tangential traction opposite to the frictional stress. An interesting phenomenon is further unveiled that, when the frictional coefficient increases, the dominant role in affecting the stick-slip state changes from the surface-induced tangential traction to the normal one, thus inspiring a feasible route to manipulate the surface effect by tuning the frictional coefficient of substrate. The present research enables one to better understand the partial-slip contact behavior of nano-indenters, which is of guiding value for anti-wear designs in nano-mechanical devices.

Thermal Structure Determines Kinematics: Vertical Shear Instability in Stellar Irradiated Protoplanetary Disks

Turbulence is crucial for protoplanetary disk dynamics, and vertical shear instability (VSI) is a promising mechanism in outer disk regions to generate turbulence. We use the Athena++ radiation module to study VSI in full and transition disks, accounting for radiation transport and stellar irradiation. We find that the thermal structure and cooling timescale significantly influence VSI behavior. The inner rim location and radial optical depth affect disk kinematics. Compared with previous vertically isothermal simulations, our full disk and transition disks with small cavities have a superheated atmosphere and cool midplane with long cooling timescales, which suppresses the corrugation mode and the associated meridional circulation. This temperature structure also produces a strong vertical shear at τ * = 1, producing an outgoing flow layer at τ * < 1 on top of an ingoing flow layer at τ * ∼ 1. The midplane becomes less turbulent, while the surface becomes more turbulent with effective α reaching ∼10−2 at τ * ≲ 1. This large surface stress drives significant surface accretion, producing substructures. Using temperature and cooling time measured/estimated from radiation-hydro simulations, we demonstrate that less computationally intensive simulations incorporating simple orbital cooling can almost reproduce radiation-hydro results. By generating synthetic images, we find that substructures are more pronounced in disks with larger cavities. The higher velocity dispersion at the gap edge could also slow particle settling. Both properties are consistent with recent near-IR and Atacama Large Millimeter/submillimeter Array (ALMA) observations. Our simulations predict that regions with significant temperature changes are accompanied by significant velocity changes, which can be tested by ALMA kinematics/chemistry observations.