Volumetric Distribution Research Articles

Structure of a shell made from uranium alloyed with iron and germanium after explosive loading

This paper presents results of metallographic examination of a thick-wall spherical shell from uranium alloyed with iron and germanium. This shell is recovered after low-level explosive loading. Light microscopy, hardness measurement, scanning electron microscopy and X-Ray diffraction study were used to investigate the meridional section of the test shell as this section most completely exhibits the whole variety of structural features associated with explosive loading of the material. Processing, presentation, and analysis of experimental data on volumetric distribution of studied physical quantities were performed with the help of digital panning and color mapping.

Mathematical modeling the process of wire surfacing by the smoothed particle hydrodynamics method

We discuss issues the process of layer-by-layer synthesis of metal products by wire surfacing. A mathematical model of the process has been developed and implemented. The model allows one to calculate the volumetric distributions of temperatures, melt flow rates, pressures, components of heat fluxes density, the shape and dimensions of the molten bath, the shape of the free surface of the molten metal, the shape and dimensions of the weld bead. For this purpose, the main physical processes that affect the formation of the metal product were considered, namely: melting and crystallization of the metal, surface tension, the Marangoni effect and the heat source features. The smoothed particle method was used to implement this model. A number of numerical experiments were carried out using the developed model. Firstly, the model parameters for steel and titanium were identified and verified. After that, calculations were carried out to verify the model itself using the obtained roller geometry. The numerical solution for the deposition of one layer was compared with the full-scale experiment. The error was no more than 5% in any direction. Thus, the efficiency and correctness of the constructed model is shown.

Modeling of 2D Functionally Graded Circular Plates with Artificial Neural Network

The thermo-mechanical properties of the functionally graded material (FGM) depend on the volumetric distribution that determines the material character, which is very important in order to overcome different operating conditions and stress levels. Three different training algorithms are used in an Artificial Neural Network (ANN) to determine the equivalent stress levels of a hollow disc that is functionally graded in two directions. The data set was created by choosing the most important four different equivalent stress values (σ_(eqv max max) ,σ_(eqv max min) ,σ_(eqv min max) ,σ_(eqv min min)) that determine the material structure in thermo-mechanical analysis. Performance estimation was performed in three different training algorithms (Gradient Descent Backpropagation, Gradient Descent with Momentum Backpropagation, BFGS Quasi-Newton Backpropagation Algorithm). In this study, termomechanical behaviour was numerically determined by using finite difference method at different compositional gradient upper values to train ANN.

Effect of Disc Position Angle and Spraying Speed on Volumetric Distribution Uniformity of Spinning Disc Nozzle

Bu araştırmanın amacı, düşük hacimli pestisit uygulamalarında kullanılan döner diskli memede disk konum açısı (0º ve 30º), ilerleme hızı (0.4 ve 1.2 m s-1) ve memeler arası mesafe (0.6, 0.7, 0.8, 0.9, 1.0, 1.1 ve 1.2 m) faktörlerinin hacimsel dağılım düzgünlüğüne olan etkisini incelemek ve optimum işletme parametrelerini belirlemektir. Laboratuvar koşullarında yürütülen püskürtme uygulamalarında doğrusal hareketli bir püskürtme simülatörü kullanılmıştır. Döner diskin devir sayısı 7000 min-1 ve püskürtme yüksekliği 40 cm olarak ayarlanmıştır. Püskürtme sıvısına 1 g l-1 konsantrasyonda Tartrazine karıştırılmıştır. Uygulamalar 30 l ha-1 norm değerinde yapılmıştır. Örnekleme için 35 mm çaplı petri kutusu kullanılmıştır. Araştırma sonuçlarına göre tüm uygulamalarda püskürtme paterni asimetrik görünümde oluşmuştur. 0° ve 30°’lik disk konum açıları için en düşük varyasyon katsayısı (CV) 0.4 m s-1 ilerleme hızında ve 0.7-0.9 m meme aralığında elde edilmiştir. 1.2 m s-1 ilerleme hızında belirlenen CV ortalamaları 0.4 m s-1 hıza göre daha yüksektir. Ancak disk konum açısı 30º olduğunda 1.2 m s-1 ilerleme hızında elde edilen CV ortalamaları 0º’lik konum açısına göre kısmen iyileşmiştir.

Quantitative filter forensics: Size distribution and particulate matter concentrations in residential buildings.

We applied filter forensics, the analysis of dust from the heating, ventilation, and air-conditioning (HVAC) filters, to measure particle size distribution in 21 residences in Toronto, Canada over a year. Four filters with different nominal efficiencies (Minimum Efficiency Reporting Value (MERV) 8-14 from ASHRAE Standard 52.2) were deployed in each residence each for three months, while the effective filtration volumes (the product of flow rate, runtime, and in-situ filter efficiency) were characterized over each filter lifetime. Using extraction and laser diffraction, we found that approximately 90% of the volumetric distributions were >10µm and the volume median diameter (VMD) ranged from 23.4 to 75.1µm. Using quantitative filter forensics (QFF), total suspended particle (TSP) concentrations ranged from 2.9 to 823.7µg/m3 (median=89.8µg/m3 ) with a moderate correlation with the content of TSP on the filters (in terms of g) and with the TSP effective filtration volume (m3 ) indicating the importance of both filter forensics and HVAC metadata parameters to QFF concentration estimates. There was no strong correlation between PM10 or PM2.5 concentrations and hourly airborne particle number concentrations measured by low-cost sensors suggesting an evaluation of QFF is warranted, particularly for the exploration of smaller particles.

Experimental and numerical investigation of hybrid laser arc welding process and the influence of welding sequence on the manufacture of stiffened flat panels

Hybrid laser arc welding (HLAW) has gained growing attention from both industry and academic laboratories for its high efficiency and weld quality. The objective of the present paper is to develop a nonlinear finite element method for predicting the weld-induced deflection and residual stress of semi-industrial scale stiffened panel, using a novel heat source model. The novel hybrid heat source consists of a Goldak's double-ellipsoid mathematical model representing the arc source, combined with a truncated cone Gaussian mathematical model to simulate the laser source. For this purpose, three-dimensional coupled thermo-elastic-plastic finite element model has been developed with ABAQUS using an additional numerical subroutine of DFLUX written in the Fortran programming language to simulate the volumetric heat flux distributions of the HLAW process. The finite element method (FEM) is verified by comparison with experimental measurements of T-joint small-scale naval EH36 steel specimens, welded in horizontal position with full penetration using hybrid laser-arc welding process (HLAW). A good agreement is observed between the numerical results and the experimental measurements, confirming that the model developed in the present paper can be used effectively to predict the deformation behaviour of the stiffened plate structures during shipbuilding. The effect of changing welding sequence on the semi-industrial scale stiffened panel has been also studied. It is concluded that the welding sequence plays an important role in the deformation of the structures. A change of direction in the middle section, in combination with alternation of the welding paths between two consecutive reinforcements welding, leads to a significant decrease of distortion.

Lighting Simulation in 3D Printing

3D printing for rapid prototyping and production of unique objects is being actively developed. Consumer-grade printers are now commonly available for a range of purposes, while increasingly advanced techniques allow us to fabricate novel shapes, mechanical properties, and appearances. The printers’ capabilities have improved dramatically from printing single-material objects to producing detailed structures with pervoxel material variation. Since the 2010s, it is possible to fabricate full-colour 3D objects with resolutions of hundreds of DPI (voxels’ dimensions are in the order of 10 μm). Such capabilities are most prominent in printers based on the photo-polymer jetting process. Ideally, it should be possible now to produce photorealistic appearances or visually indistinguishable objects copies for, e.g., cultural-heritage applications.However, the resins used as print materials in commercial devices are inherently translucent, i.e., exhibit significant sub-surface scattering. This serves effective colour mixing in full-colour print processes, thus commercial printer drivers offer high-quality colour reproduction. At the same time, the resulting light diffusion leads to over-blurring and potential colour bleeding when printingspatially-varying colour textures. This translucent ‘crosstalk’ between surface points also strongly depends on the internal structure of the volume surrounding each surface point.Previously existing scattering-aware methods used simplified models for light diffusion and accepted the visual blur as an immutable property of the print medium.In this talk, we present the series of works conducted by a consortium of several institutes (Max-Planck Institute for Informatics, Germany; Charles University in Prague, Czech Republic; Institute of Science and Technology, Austria; University Col-lege London, United Kingdom; Universita della Svizzera Italiana, Switzerland; The Keldysh Institute of Applied Mathematics RAS, Russia). Our work counteracts heterogeneous scattering to obtain the impression of a crisp albedo texture on top of the 3D print, by optimizing for a fully volumetric material distribution that preserves the target appearance.We build our iterative method on top of a general Monte-Carlo simulation of heterogeneous scattering. We find out that a certain arrangement of materials expands the gamut of achievable appearances and makes it possible to produce sharp textures. This knowledge built-in into the volume-update step enables convergence justafter 10–15 iterations. We verify these findings using an established stochastic gradient-descent optimization for small canonical objects where it is feasible computationally.Expansion of our method to fabrication of arbitrary 3D objects with the translucent resins opens a set of problems of achievable colour combinations on the two sides of thin shapes, in the extreme convex and concave shapes. Physically correct lighting simulation enables exploration of these extreme cases where no ideal solution is possible. It turns out that a re-formulation of established gamut-mapping methods is needed for the medium with the inherent cross-talk properties such as the scattering resins of the modern full-colour 3D printers.Elaborating further ideas from we also propose a fast forward predictor of the object's surface appearance based on a neural network to replace the Monte-Carlo simulation in order to speed up the preparation of the model by 300 times. The achieved acceleration allows to reduce simulation time to minutes for a single, GPU-equipped workstation.Thismakesthe print preparation timings practical.

Volumetric distribution of perivascular space in relation to mild cognitive impairment

Vascular contributions to early cognitive decline are increasingly recognized, prompting further investigation into the nature of related changes in perivascular spaces (PVS). Using magnetic resonance imaging, we show that, compared to a cognitively normal sample, individuals with early cognitive dysfunction have altered PVS presence and distribution, irrespective of Amyloid-β. Surprisingly, we noted lower PVS presence in the anterosuperior medial temporal lobe (asMTL) (1.29 times lower PVS volume fraction in cognitively impaired individuals, p < 0.0001), which was associated with entorhinal neurofibrillary tau tangle deposition (beta (standard error) = -0.98 (0.4); p = 0.014), one of the hallmarks of early Alzheimer’s disease pathology. We also observed higher PVS volume fraction in centrum semi-ovale of the white matter, but only in female participants (1.47 times higher PVS volume fraction in cognitively impaired individuals, p = 0.0011). We also observed PVS changes in participants with history of hypertension (higher in the white matter and lower in the asMTL). Our results suggest that anatomically specific alteration of the PVS is an early neuroimaging feature of cognitive impairment in aging adults, which is differentially manifested in female.

An experimental/numerical hydrothermal-Second law analysis of a finned/tubular heat exchanger using Bhatnagar–Gross–Krook Lattice Boltzmann (BGKLBM) and rheological-thermal behavior of Fe2O3-water

Purpose The purpose of this study is analysis of the natural convection and entropy production in a two-dimensional section of the considered heat exchanger. For this purpose, the lattice Boltzmann method which is equipped with Bhatnagar–Gross–Krook model is used. This model proposes a significant accurate prediction for thermal and hydro-dynamical behaviors over free convection phenomenon. The heat exchanger is filled with Fe2O3-water nanofluid. To improve the accuracy of prediction, it is neglected to use the theoretical models for properties of nanofluid. At this end, some experimental observations are conducted, and the required rheological and thermal properties of nanofluid are measured based on laboratory work.. Design/methodology/approach The present work focuses on the influence of different factors on the thermal behaviors and entropy production of a heat exchanger. The heat exchanger is consisted by an inner tube, an outer tube and some fins which are implanted at the surface of inner tube. Findings The effects of various factors like structure of inner fins, nanoparticle concentration and Rayleigh number over the heat transfer rate, local and volumetric entropy production, Bejan number, flow configuration and temperature distributions are provided. Originality/value The originality of this work is using a new-developed numerical method for treating natural convection and experimental measurements for thermal and rheological properties of nanofluid.

A New Design of Tubular Ceramic Membrane Module for Oily Water Treatment: Multiphase Flow Behavior and Performance Evaluation.

Petroleum has been extracted from oil reservoirs using different techniques. This activity is accompanied for a large amount of water and sometimes mixed with gas. This produced water has a high oil concentration and other toxic chemical compounds, thus, it must be treated to be reused or released to environment according to environmental protection regulations. Currently, ceramic membrane technology has been employed in the wastewater treatment, due to its high benefit–cost ratio. In this sense, this work aims to study the oil–water mixture separation process using a new configuration of tubular ceramic membrane module by computational fluid dynamic (ANSYS Fluent software). The proposed model is composed of mass and linear momentum conservation equations coupled to Darcy’s law and SST k-ω turbulence model. Results of the volumetric fraction, pressure, and velocity distribution of the oil and water phases are presented and discussed. The results indicated that the proposed model and new device both have great potential to be used on the water/oil separation process and that the transmembrane pressure remains constant in the axial direction and decreases radially through the membranes, indicating an efficient system that favors the transport of clean water and oil retention.

Planar capacitive imaging for composite delamination damage characterization

The objective of this study is to develop and validate a noncontact, nondestructive inspection and imaging method for rapidly assessing the subsurface condition of carbon fiber-reinforced polymer (CFRP) composite structures. The method works on the principle of planar electrical capacitance tomography (ECT). Unlike conventional ECT systems, electrodes are arranged on a rectangular planar surface in the form of a grid. The volume on one side of the electrode plane is interrogated with an electric field, and the mutual capacitances between the electrodes are measured. The volumetric electrical permittivity distribution of the interrogated region is then reconstructed from the measured capacitance responses. In this work, an ECT image reconstruction algorithm was implemented, and a customized planar capacitive imaging system was prototyped. First, different objects were placed near the electrode array, and the corresponding volumetric change in electrical permittivity was successfully captured. Second, the planar ECT system was employed for detecting artificially introduced subsurface defects in 3D-printed objects. Third, CFRP specimens with different sizes of single-layer delamination were fabricated and subjected to ECT interrogation. The results confirmed that the planar ECT system could detect the location and size of delamination in CFRP panels. The accuracy and resolution of the planar ECT prototype were also characterized.

A Design for Additive Manufacturing approach based on process energy efficiency: Electron beam melted components

Abstract In the present paper a Design for Additive Manufacturing approach is proposed, with the aim to outline a generalized method and define an energy consumption model that allow, during the development of component design, to evaluate the effects of the different solutions on the energy efficiency of the additive process that will build the component. For this purpose the concept of building energy is introduced, that is the real energy of the heat source during the phases of the building process, and can be directly correlated to key properties of the component (material, geometry and shape, volumetric distribution). For the detailed formulation of the energy consumption model, the Electron Beam Melting technology has been considered. Two parameters are identified to effectively characterize each design solution, combining the geometric and volumetric properties of components in the most significant way, and taking into account also the efficiency in build volume packing. The application of the model to the fabrication of components characterized by different shape classes is detailed, highlighting how a different spatial distribution of the same volume affects the building energy. The outcomes in terms of energy consumption, due to alternative design choices, can be assessed and simulated. The analysis of critical points in the design solutions presents an heuristic potential, as it can guide the designer in effective improvement interventions. The accuracy in the evaluation of the process energy consumption due to the proposed approach, also suggest limiting the use of simplifications, that may not be fully suitable to correlate energy efficiency and component properties in a Design for Additive Manufacturing perspective.

Thermo-Fluid Dynamics Analysis of Fire Smoke Dispersion and Control Strategy in Buildings

Smoke is the main threat of death in fires. For this reason, it becomes extremely important to understand the dispersion of this pollutant and to verify the influence of different control systems on its spread through buildings, in order to avoid or minimize its effects on living beings. Thus, this work aims to perform thermo-fluid dynamic study of smoke dispersion in a closed environment. All numerical analysis was performed using the Fire Dynamics Simulator (FDS) software. Different simulations were carried out to evaluate the influence of the exhaust system (natural or mechanical), the heat release rate (HRR), ventilation and the smoke curtain in the pollutant dispersion. Results of the smoke layer interface height, temperature profile, average exhaust volumetric flow rate, pressure and velocity distribution are presented and discussed. The results indicate that an increase in the natural exhaust area increases the smoke layer interface height, only for the well-ventilated compartment (open windows); an increase in the HRR accelerates the downward vertical displacement of the smoke layer and that the 3 m smoke curtain is efficient in exhausting smoke, only in the case of poorly ventilated compartments (i.e., with closed windows).

A high-performance battery-like supercapacitor electrode with a continuous NiTe network skeleton running throughout Co(OH)2/Co9S8 nanohybrid

There has been an ongoing effort in pursuing high-energy-density supercapacitor to facilitate its practical applications in energy storage devices. Currently, constructing a composite electrode using multiple battery-type materials or battery-like capacitive materials has been perceived as a promising solution. On one hand, the rational composition/microstructure design is highly desirable to improve the volumetric stress distribution and enhance the overall electrical conductivity. Accordingly, we develop a battery-like (Co(OH)2/Co9S8)@NiTe/Ni composite electrode, in which the continuous NiTe network skeleton running throughout Co(OH)2/Co9S8 nanohybrid acts as the fast electron transfer channel and the buffer against volumetric strain. The electrode delivers a high areal capacitance of 5.28 F cm−2 at a current density of 10 mA cm−2 and demonstrates a super-long cycle life of 50,000 cycles due to the good electrical conductivity, buffer effect of NiTe skeleton and the capacitance contributions from multiple constituents. Thereafter, the assembled aqueous or quasi-solid-state (Co(OH)2/Co9S8)@NiTe/Ni//AC asymmetric supercapacitor demonstrates high areal energy density exceeding 0.88 mWh cm−2 as well as long cycle life exceeding 35,000 cycles. The fabricated battery-like supercapacitor electrode can be engineered to satisfy the long-term, high-power and high-energy-density application requirements.

Effect of Power Law Fluids Rheology on The Structure of Cuttings and Drilling Fluid Flow in Wellbore Eccentric Annulus (Dept.M)

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Highly Tunable Thiol-Ene Photoresins for Volumetric Additive Manufacturing.

Volumetric additive manufacturing (VAM) forms complete 3D objects in a single photocuring operation without layering defects, enabling 3D printed polymer parts with mechanical properties similar to their bulk material counterparts. This study presents the first report of VAM-printed thiol-ene resins. With well-ordered molecular networks, thiol-ene chemistry accesses polymer materials with a wide range of mechanical properties, moving VAM beyond the limitations of commonly used acrylate formulations. Since free-radical thiol-ene polymerization is not inhibited by oxygen, the nonlinear threshold response required in VAM is introduced by incorporating 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) as a radical scavenger. Tuning of the reaction kinetics is accomplished by balancing inhibitor and initiator content. Coupling this with quantitative measurements of the absorbed volumetric optical dose allows control of polymer conversion and gelation during printing. Importantly, this work thereby establishes the first comprehensive framework for spatial-temporal control over volumetric energy distribution, demonstrating structures 3D printed in thiol-ene resin by means of tomographic volumetric VAM. Mechanical characterization of this thiol-ene system, with varied ratios of isocyanurate and triethylene glycol monomers, reveals highly tunable mechanical response far more versatile than identical acrylate-based resins. This broadens the range of materials and properties available for VAM, taking another step toward high-performance printed polymers.

Multiscale Computational Fluid Dynamics Modeling for Personalized Liver Cancer Radioembolization Dosimetry.

Yttrium-90 (90Y) radioembolization is a minimally invasive procedure increasingly used for advanced liver cancer treatment. In this method, radioactive microspheres are injected into the hepatic arterial bloodstream to target, irradiate, and kill cancer cells. Accurate and precise treatment planning can lead to more efficient and safer treatment by delivering a higher radiation dose to the tumor while minimizing the exposure of the surrounding liver parenchyma. Treatment planning primarily relies on the estimated radiation dose delivered to tissue. However, current methods used to estimate the dose are based on simplified assumptions that make the dosimetry results unreliable. In this work, we present a computational model to predict the radiation dose from the 90Y activity in different liver segments to provide a more realistic and personalized dosimetry. Computational fluid dynamics (CFD) simulations were performed in a 3D hepatic arterial tree model segmented from cone-beam CT angiographic data obtained from a patient with hepatocellular carcinoma (HCC). The microsphere trajectories were predicted from the velocity field. 90Y dose distribution was then calculated from the volumetric distribution of the microspheres. Two injection locations were considered for the microsphere administration, a lobar and a selective injection. Results showed that 22% and 82% of the microspheres were delivered to the tumor, after each injection, respectively, and the combination of both injections ultimately delivered 49% of the total administered 90Y microspheres to the tumor. Results also illustrated the nonhomogeneous distribution of microspheres between liver segments, indicating the importance of developing patient-specific dosimetry methods for effective radioembolization treatment.

Three-Dimensional Morphogeometric and Volumetric Characterization of Cornea in Pediatric Patients With Early Keratoconus

To present morphogeometric and volumetric characteristics of the cornea and its diagnostic value in pediatric patients with keratoconus (KC) using 3-dimensional (3-D) corneal modeling. Cross-sectional study. This single-center (VISSUM Innovation, Alicante, Spain) study comprised 49 eyes of 49 pediatric patients (age ≤16 years) with KC and 31 eyes of 31 healthy pediatric controls. Eyes were graded as early (n= 21) and mild KC (n= 28) based on the RETICS (Thematic Network for Co-Operative Research in Health) classification system. The 3-D corneal model was generated using raw topographic data. Deviation of anterior (Dapexant) and posterior (Dapexpost) apex and minimum thickness points (Dmctant, Dmctpost), Dapexant-Dapexpost difference, total corneal volume (Vtotal), volumetric distribution (VOLAAP, VOLPAP, and VOLMCT), and percentage of relative volume increase (VOLAAPrel, VOLPAPrel, and VOLMCTrel) between 2 consecutive radii centered to anterior/posterior apex and thinnest point were evaluated. Dapexpost and Dapexant-Dapexpost difference were higher in the early and mild KC groups compared to the control group (P < .05). Eyes with early and mild KC had decreased Vtotal compared with the control group (P < .05). Dapexpost, Dapexant-Dapexpost difference, and VOLMCTrel between 1.0 and 1.4mm diameters had area under receiver operating characteristics curve (AUROC) values over 0.93 in discrimination of early KC from normal. This is the first study presenting morphogeometric and volumetric characterization of cornea in pediatric patients with early and mild KC using a 3-D corneal model. Integration of the morphogeometric and volumetric parameters to topography software can add value in early detection of KC in pediatric patients.

VRIF Guidelines on Live VR Services

Founded at the Consumer Electronics Show in 2017, the Virtual Reality Industry Forum (VRIF) ( www.vr-if.org ) is chartered with the mission to further the widespread availability of high-quality audiovisual virtual reality (VR) experiences. Its charter includes delivering guidelines and advocating industry consensus around common technical standards for end-to-end VR interoperability from content production through distribution to consumption. VRIF delivered the first release of its Guidelines 1 in early 2018 detailing an initial set of best practices and recommendations for realizing high-quality, interoperable 360° video experiences. Its latest Guidelines version 2.2 (2020) includes new features such as live VR services, high dynamic range (HDR) support, use of text and fonts, and watermarking for theatrical VR. Currently, VRIF is working on new features around volumetric content production and distribution, cloud VR and edge computing, enhanced 360° video support, and enabling social VR experiences.

Effects of freeze-thaw cycles on soil macropores and its implications on formation of hummocks in alpine meadows in the Qinghai Lake watershed, northeastern Qinghai-Tibet Plateau

The alpine regions are characterized by frequent freeze-thaw cycles, which influence the soil structure remarkably. However, the effects of freeze-thaw cycles on the soil macropore structure and its implications on the formation of hummocks are not well understood. This study aims to quantify the soil macropores of hummocks and the effects of freeze-thaw cycles on soil macropores to reveal its implications on the formation of hummocks in alpine meadows. A total of nine intact soil columns (0–50 cm deep) were excavated from the alpine meadows. Three replicates were collected from the hummocks and three were collected from the interhummocks, and they were scanned by X-ray computed tomography (CT). Another three replicates were excavated from the adjacent non-hummock alpine meadows, which were subjected to successive freeze-thaw cycles (0, 1, 3, and 6) and then scanned using X-ray CT. Soil macropore network of hummocks was more extensive and continuous than that of the interhummocks. The volumetric distribution of soil macropores in hummocks was multiple, while soil macropores of the interhummocks intensively fell in the volume range of 0–400 mm3. The soil macroporosity, macropore number density, surface area density, length density, node density, branch density, and mean macropore size of the hummocks were several times higher than those of the interhummocks. These soil macropore parameters showed a decrease after the first and third freeze-thaw cycle and later increased through the next three cycles. Soil macropores with volume > 1000 mm3 transformed into smaller ones (600–1000 mm3) during the freeze-thaw process. The soil macropore patterns of hummocks and interhummocks differed distinctly. Soil macropores responded significantly to freeze-thaw cycles. The effects of freeze-thaw cycles on the macropore number and size were more significant than on the morphology in alpine meadows. Hummock formation is closely related to the soil macropores during the freeze-thaw cycles, and the soil moisture played a crucial role in the hummock formation process.