Trapping Area Research Articles

Topography‐Enhanced Ultra‐Cold Trapping at the LCROSS Impact Site

AbstractSmall topographic features below the resolution of existing orbital data sets may create “micro ultra‐cold traps” within the larger permanently shadowed regions that are present at the lunar poles. These ultra‐cold traps are protected from the major primary and secondary illumination sources, and thus would create surfaces that are much colder than lower‐resolution temperature maps would indicate. We examine this effect by creating a high resolution (1 m pix−1) terrain map based on upscaled data from the Lunar Orbiter Laser Altimeter. This map is illuminated by scattered sunlight and infrared emissions from sunlit terrain, which are then run through a thermal model to determine temperatures. We find that while most of the terrain experiences maximum temperatures around 50 K, there are a number of 1–30 m‐scale ultra‐cold traps with maximum temperatures as low as 20–30 K. By comparing our modeled ultra‐cold trapping area to volatile abundances measured by Lunar Crater Observation and Sensing Satellite (LCROSS), we reveal a diverse environment where the surficial abundances necessary to explain the LCROSS results are strongly dependent on precisely where the impact occurred.

Lunar North Polar Cold Traps Based on Diurnally and Seasonally Varying Temperatures

Lunar cold traps are defined by extremely low sublimation rates, such that water ice could have accumulated in them. Here time-averaged sublimation rates are calculated for the north polar region of the Moon based on over 14 years of Diviner surface temperature measurements. Data for each spatial pixel are binned according to subsolar (diurnal) and ecliptic (seasonal) longitude. The cold trap area poleward of 80°N is about 32% larger when defined by a time-average sublimation rate instead of by peak temperature. Apparently sunlit cold traps are identified, e.g., in Lenard Crater, where modeling of direct illumination reveals that the Sun briefly rises above the horizon each Draconic year. The true cold trap area is smaller than what can be determined from Diviner data. Also presented are north polar maps for the potential sublimation rate of relic buried ice and for subsurface cold trapping.

Geological conditions, genetic mechanisms and accumulation patterns of helium resources

Based on the methodology for petroleum systems and through the anatomy and geochemical study of typical helium-rich gas fields, the geological conditions, genesis mechanisms, and accumulation patterns of helium resources in natural gas are investigated. Helium differs greatly from other natural gas resources in generation, migration, and accumulation. Helium is generated due to the slow alpha decay of basement U/Th-rich elements or released from the deep crust and mantle, and then migrates along the composite transport system to natural gas reservoirs, where it accumulates with a suitable carrier gas. Helium migration and transport are controlled by the transport system consisting of lithospheric faults, basement faults, sedimentary layer faults, and effective transport layers. Based on the analysis of the helium-gas-water phase equilibrium in underground fluids and the phase-potential coupling, three occurrence states, i.e. water-soluble phase, gas-soluble phase and free phase, in the process of helium migration and accumulation, and three migration modes of helium, i.e. mass flow, seepage, and diffusion, are proposed. The formation and enrichment of helium-rich gas reservoirs are controlled by three major factors, i.e. high-quality helium source, high-efficiency transport and suitable carrier, and conform to three accumulation mechanisms, i.e. exsolution and convergence, buoyancy-driven, and differential pressure displacement. The helium-rich gas reservoirs discovered follow the distribution rule and accumulation pattern of “near helium source, adjacent to fault, low potential area, and high position”. To explore and evaluate helium-rich areas, it is necessary to conduct concurrent/parallel exploration of natural gas. The comprehensive evaluation and selection of profitable helium-rich areas with the characteristics of “source-trap connected, low fluid potential and high position, and proper natural gas volume matched with helium’s” should focus on the coupling and matching of the helium “source, migration, and accumulation elements” with the natural gas “source, reservoir and caprock conditions”, and favorable carrier gas trap areas in local low fluid potential and high positions.

Visualization of surface discharge area in SF6 based on infrared trap

A method for visualization of surface discharge area in SF6 based on infrared trap is proposed in this study. The infrared images of a heated insulator with a surface defect under different applied voltages were studied, and the infrared trap phenomenon was observed in the infrared image. When partial discharge occurs on the heated insulator surface, a spindle shaped infrared trap will be formed at the end of the defect. In the infrared trap area, the apparent temperature measured using the infrared camera decreases compared to that without discharge. The infrared trap area corresponds to surface discharge area. With the increase in the applied voltage, the discharge becomes more severe, the infrared trap area gradually expands, and the trap depth also increases. This infrared trap phenomenon found in this study can serve as a method to visualize the surface discharge area in SF6 gas.

Camera-traps detect the maned wolf preying on broad-snouted caiman eggs

The maned wolf (Chrysocyon brachyurus) is a South-American canid of which conservation guidelines have been implemented due to its population vulnerability. Its trophic ecology demonstrates an omnivorous and opportunistic diet, and even flexibility in response to anthropogenic disturbances. Among the food items identified, the consumption of reptiles is scarce, and includes snakes and lizards. We monitored broad-snouted caiman (Caiman latirostris) nests during four nesting seasons through camera trapping, in savannas and grasslands areas, and recorded maned wolves feeding on caiman eggs during periods of drought. The consumption of an uncommon item, even at low frequency, suggests that camera trapping could become a complementary tool for studying the dietary habits of the maned wolf. Caimans have been a priority for conservation, while maned wolves are currently being released and reintroduced in order to reverse their vulnerable population status. This trophic interaction must be monitored in the long term, to project integral conservation strategies that include both emblematic species.

Trapping of low and high refractive index nano-spherical particles by using a highly focused Laguerre-Gaussian beam.

We have investigated the trapping force on low and high refractive index nano-particles using a highly focused Laguerre-Gaussian beam. An analytical expression for the gradient force has been derived in closed form. It was clearly found that the increase of the beam mode p causes a substantial increase in the number of trapping zones, which frequently increases the number of particles to be captured simultaneously. Also, the decrease of p values would increase the trap area, which consequently leads to simultaneous trapping of multiple particles in the same area. The change of p, l, Δ n, and z 1 values has a direct influence on the gradient forces. The smaller values of scattering and thermal forces relative to the gradient force values represent essential conditions for the stability of the trapping performance.

Estimating the effective sampling area of an alcohol-baited trap for monitoring the coffee berry borer

Estimating the effective sampling area of an alcohol-baited trap for monitoring the coffee berry borer

The effect of central flux trap on-line sampling on Tehran Research Reactor(TRR) core safety parameters

Introducing the Neutron Flux Trap Channel to research reactors is an effective method to increase the neutron flux utilization for conducting the irradiation experiment and radioisotope production. The maximum thermal neutron flux could be achieved due to increased moderation in the flux trap area surrounded by the fuel elements, while all safety parameters and criteria must be met during the operation of the reactor. Regarding the TRR operator’s report about induced positive reactivity due to the entrance of some samples during reactor operation, it is predicted that this region is over-moderated, and the moderator reactivity coefficient is positive locally. Hence, this study aims to analyze experimental observations and the reactor safety parameters during online sampling into the flux trap channel. In this analysis, TRR Core’s different operating cycles were studied, and static, kinetic, and dynamic parameters of the reactor core with or without a flux trap channel were evaluated. For this purpose, some experiments were conducted to determine the safety parameters resulting from the sample placement, and then calculation results were validated against the experimental ones. Results indicate that void and temperature reactivity coefficients in the flux trap channel are locally positive; for example, the temperature and void reactivity coefficients for operating cycles with 33 fuel assemblies are +3.60 pcm/°C and +18.39 pcm/%, respectively. If 56.7% void is created in this channel, about 1.080$ positive reactivity will be induced to the core.Finally, accident analysis was conducted during various scenarios of reactivity insertion of different samples, and the variation of reactor power, reactivity, and fuel and clad temperatures were estimated in different transients. It is indicated that the maximum fuel and cladding temperatures in the worst case will be 183 °C and 144 °C, respectively, less than the melting point of aluminum meat of fuel.

Estimating the abundance of benthic invertebrates from trap-catch data

Abstract Trap fisheries targeting invertebrates are economically important but many of the target species lack stock assessments. One reason for this is the difficulty of estimating density. One important means by which density can be estimated uses the catch rates of baited traps that are spaced at different distances. With declining spacing, the sphere of attraction will increasingly overlap, leading to reductions in catches, allowing for the estimation of the density that is catchable by traps on the seabed. Here we review the analytical methods adopted across a range of studies and find that no consensus on robust methods exists. We propose an analytical method that assumes the trapping area is circular and that the chance of catching an individual declines linearly with distance from the trap. We apply this method to estimate the density and the trapping radius of crabs and gastropods from real and simulated datasets. The method estimated a trapping radius of between 4 and 86 m, and densities that are up to 2.5 times less and 13 times greater than estimates provided in the original sources, illustrating the sensitivity to methodology. In conclusion, we provide and test a standardized method to estimate the density of benthic invertebrates.

NUMERICAL SIMULATION OF GAS AND WATER FILTRATION IN MICROMODEL OF POROUS MEDIUM WITH A FRACTURE AND TRAPS

To select effective displacement agents, in order to limit waterflow to gas wells, it is necessary to understand the behavior of the multiphasesystem at the scale of individual pores, where capillary forces playan important role. In turn, capillary forces depend on interfacial tensionand wettability. As part of this work, computational microfluidics methodsusing the Open FOAM platform were used to analyze the effect of rockwettability on the features of two-phase filtration of water and gas in theporous medium model with fractures and traps.A mathematical model has been chosen that allows you to describe themovement of fluid in a fracture by the Navier-Stokes equations, and in theelements of a porous matrix by Darcy's law. Multivariable analysis ofwater displacement by gas was performed for different flow modes in caseof hydrophobic and hydrophilic surfaces. It has been shown that in thecase of a hydrophilic surface, the displaced water remains in the fracture«traps» in contrast to the hydrophobic surface, where the water is displacedcompletely. It has also been shown that as permeability increases,most of the gas is filtered into the matrix. However, for the hydrophilicsurface in the trap area, no filtration into the formation occurs, which isassociated with water capture in the fracture traps. It has been found thatmore intensive water washout occurs at low filtration rates. By displacingwater with filtration into a porous medium, most of the water can be lefttrapped, as opposed to displacing without filtration into a porous matrix.The proposed approach can be used as a screening technology to select theoptimal filtration modes and use modifiers for wetting the bottomholezone in order to limit water inflow into gas wells.

Estimating plume reach and trapping radii for male and female Cydia pomonella (Lepidoptera: Tortricidae) captured in pheromone-kairomone baited traps in Washington State apple orchards under mating disruption.

Male Cydia pomonella (L.) (Lepidoptera: Tortricidae) dispersion has largely been studied in nonmating disrupted orchards due to synthetic pheromone interference with capture in monitoring traps. Little is known about female dispersion. This study aimed to characterize male and female dispersion in mating disrupted commercial apple orchards. Sterile C. pomonella recapture data from single-trap multiple-release experiments using PHEROCON CM-DA COMBO + AA Lure-baited orange Pherocon VI delta traps was interpreted to determine pheromone-kairomone lure-baited trap effective area, trap deployment density for effective monitoring, and absolute male and female C. pomonella density in mating disrupted Washington commercial apple orchards. The maximum plume reach of the pheromone-kairomone lure in mating disrupted orchards was <5 m from the baited trap for both sexes. Maximum dispersive distances for 95% of the released C. pomonella in mating disrupted orchards were 106 and 135 m for males and females, yielding trapping areas of 3.87 and 6.16 ha, respectively. Estimates were consistent across 3 growing seasons and represent the first records of male and female dispersal distance and monitoring trap efficacy from commercial C. pomonella mating disrupted apple orchards. With relevance to commercial monitoring programs and economic thresholds in mating disrupted orchards, traps should be deployed at a density of 1 per 3-6 ha. Capture of a single male or female C. pomonella corresponds to at least 82-104 C. pomonella within the 3-6 ha trapping area. This refined C. pomonella capture interpretation in pheromone-kairomone baited traps in mating disrupted commercial apple orchards yields more precise damage estimates and assists in insecticide-use decision making.

Geological Characteristics of Shale Reservoir of Pingdiquan Formation in Huoshaoshan Area, Junggar Basin

Unconventional oil and gas, represented by shale gas and shale oil, have occupied an important position in global energy. The rapid growth of shale gas and shale oil production shows great potential for the exploration and development of shale resources. Junggar basin, the main oil-bearing basin in China, is rich in oil and gas resources, so it is of great practical significance to carry out systematic research on the geological characteristics of shale reservoirs in this region. To this end, this paper designates the shale reservoir of Pingdiquan Formation in Huoshaoshan area of the Jungar Basin as the research object, carries out a geological survey in that area, analyzes reservoir forming conditions using the geological interpretation method, analyzes different local trap reservoir types and their main control factors by dissecting the explored reservoir, optimizes and evaluates favorable traps using the source, fault, facies and circle coupling analysis method, establishes single good identification standard of sedimentary microfacies, and carries out well-connected sedimentary microfacies analysis. Using geochemical methods, such as rock pyrolysis, maceral analysis, vitrinite reflectance, kerogen carbon isotope, saturated hydrocarbon chromatography, etc., the abundance and types of organic matter of shale in different intervals are analyzed and the geological characteristics of shale reservoirs are evaluated. This paper aims to analyze the oil and gas content of the shale reservoir in Pingdiquan Formation in the Junggar Basin to provide reliable reservoir evaluation and guide better development of shale oil and gas resources in the future. The innovative expenditure of this paper lies in conducting the research from two aspects: the analysis of the main controlling factors of reservoir formation from the structural point of view and the analysis of the pore structure and geochemical characteristics of shale from the core experiment point of view, and also the classification of organic matter, so as to provide a basis for finding favorable traps. The results show that the shale sedimentary system in the study area is a small fluvial delta, which belongs to a compression structure, with developed NNE-oriented structural belts and faults; the structural form is a short-axis anticline as a whole, forming a structural coil closure at −900 m, with a trap area of 50 km2 and a closure height of 180 m. According to the geological interpretation method, 19 faults of all levels were found in the area and the vertical migration conditions of oil and gas were good. Pingdiquan Formation was oil-bearing, with many vertical oil-bearing strata and strong horizontal independence of the reservoir. The sedimentary thickness of the Permian Pingdiquan Formation in the study area is 300~1200 m and the oil-bearing strata are divided into 3 oil-bearing formations, 9 sublayers, and 22 monolayers from top to bottom. The abundance of organic matter in different strata is generally high, with an average total organic carbon content of 3.53%, an average hydrocarbon generation potential of 18.1 mg/g, an average chloroform asphalt content of 0.57%, and an average total hydrocarbon content of 3011 μg/g, all of which belong to the shale standard, especially Ping-2. The organic matter in different layers belongs to types I-II1, and the organic matter types are I-II1, I-II2, and II1-II2, respectively. The average carbon isotope of shale kerogen is −2.4%, which belongs to type II2 kerogen.

OrganoidChip facilitates hydrogel-free immobilization for fast and blur-free imaging of organoids

Organoids are three-dimensional structures of self-assembled cell aggregates that mimic anatomical features of in vivo organs and can serve as in vitro miniaturized organ models for drug testing. The most efficient way of studying drug toxicity and efficacy requires high-resolution imaging of a large number of organoids acquired in the least amount of time. Currently missing are suitable platforms capable of fast-paced high-content imaging of organoids. To address this knowledge gap, we present the OrganoidChip, a microfluidic imaging platform that incorporates a unique design to immobilize organoids for endpoint, fast imaging. The chip contains six parallel trapping areas, each having a staging and immobilization chamber, that receives organoids transferred from their native culture plates and anchors them, respectively. We first demonstrate that the OrganoidChip can efficiently immobilize intestinal and cardiac organoids without compromising their viability and functionality. Next, we show the capability of our device in assessing the dose-dependent responses of organoids’ viability and spontaneous contraction properties to Doxorubicin treatment and obtaining results that are similar to off-chip experiments. Importantly, the chip enables organoid imaging at speeds that are an order of magnitude faster than conventional imaging platforms and prevents the acquisition of blurry images caused by organoid drifting, swimming, and fast stage movements. Taken together, the OrganoidChip is a promising microfluidic platform that can serve as a building block for a multiwell plate format that can provide high-throughput and high-resolution imaging of organoids in the future.

Examining the bias of pitfall traps with enclosure experiments and removal sampling

Abstract Pitfall trapping is among the most widely used sampling methods for ground‐dwelling beetles. However, the sampled ground‐dwelling beetle abundance in pitfall traps may be biased, which can lead to difficulties when comparing the sampled abundance between different habitats. To better understand the comparability of the sampled abundance, we focused on two sampling processes: a temporary migration process (referring to the individual movements into and out of the effective trap area) and a removal process (determining the number of individuals collected given the number of individuals within the trap area). To examine the effects of the temporary migration process, we compared the sampled abundance of 10 ground‐dwelling beetle species inside and outside enclosures in 2 habitats (clear‐cut and forested sites) and found that installing the enclosure decreased the sampled abundance in both habitats, but the effects did not differ among habitats. To examine the effects of the removal process, we examined the effects of daily soil temperature on the daily sampled abundance (removal probability) of Pterostichus thunbergi using removal sampling within enclosures. We found that soil temperature increased the removal probability, but this effect was limited and not consistent across survey periods. The results suggest that the effects of the temporary migration process may not be habitat dependent and that the effects of the removal process may be small. Therefore, the traditional use of pitfall traps is, to some extent, a robust and comparable measure of the sampled abundance of ground‐dwelling beetles among different habitats.

Adhesion of cold sprayed soft coatings: Effect of substrate roughness and hardness

When depositing a soft material (e.g. pure Cu) onto a harder substrate (e.g. stainless steel) by cold spraying, the attainable coating adhesion depends on both the hardness and the roughness of the substrate. To decouple their respective influences, the present work focuses on a model system of cold sprayed copper onto AISI 304 steel surfaces with differently adjusted hardness and roughness values. AISI 304 stainless steel plates were either polished or grit-blasted to different roughness, and then employed as substrates either as-is, i.e. in the “hardened” condition, or in the “softened” vacuum-annealed state. SEM analyses and nano-indentation tests showed that grit-blasting causes severe plastic deformation of the surface, where any visible austenite grain structure is lost up to a depth of some tens of microns. The corresponding microstructures are work-hardened, reaching a hardness of about 350–400 HV0.001. Vacuum annealing induced recrystallization and restored the original, lower hardness (≈200 HV0.001) of AISI 304, without changing the surface roughness, as obtained by the grit-blasting. Through cavitation tests on single-particle deposition experiments, it was found that cold sprayed Cu particles' adhesion was lower on roughened and hardened substrates than on polished surfaces. In contrast, the situation was reversed for roughened and annealed (“softened”) substrates, showing an increase in adhesion of cold-sprayed Cu particles with increasing roughness up to a maximum at Rz of about 34 μm. The latter trend was confirmed by bond strength testing of complete Cu coatings onto “softened” substrates, while the maximum adhesion on hardened substrates was attained with Rz = 18 μm. The underlying mechanisms are discussed with respect to particle deformation and the substrate surface topographies needed to trap areas of mutual shear instabilities of the particles and the substrate. Identifying the conditions that ensure metallurgical bonding then should help to provide a more general understanding of deposit adhesion in cold spraying.

Influences of lubrication on asymmetric peristaltic movement and its bifurcation

Peristaltic motions are used in a variety of industrial and real-world problems such as pumping mixture with such a high solid content from the mining sector, biogases, sewers facilities, food flow through the gastrointestinal system, urinary tract, and fallopian tube of human females where extremely abrasive, gritty, and viscous fluids are present. The goal of this theoretical study is to examine the impact of the lubricated walls on the peristaltic transport of a viscous fluid in an asymmetric medium. The interfacial condition is derived under the assumptions of thin film lubrication and long wavelength approximation. The theory of a dynamical system is utilized to examine the lubrication effects on the position and bifurcation of stagnation points in the flow. For this, three flow distributions, backward flow, trapping, and augmented flow, are discussed. The obtained system of equations is solved numerically by the shooting method based on Newton–Raphson root-finding algorithm in Mathematica. The prime findings for the velocity profile, pressure increase, trapping, and reflux criteria are illustrated through graphs. Bifurcation occurs earlier by increasing the influence of lubrication. The trapping area diminishes and the augmented flow section expands with the lubrication parameter. This will be useful for medical engineering, industrial and physiological systems. The comparison for the particular case of no-slip condition is presented and found to be in excellent agreement.

Transport of Sediment Mixtures in Steady Flow with an Extra Contribution of Their Finest Fractions: Laboratory Tests and Modeling

This paper presents the results of experimental studies on the transport of water-sandy mixtures with the content of very fine non-cohesive fractions in steady flow. The flow and shear velocity measurements as well as the measurements of sediment amount in the trap and control area were conducted. A theoretical model of the vertical structure of both velocity and concentration of sediment non-cohesive fractions as well as vertical mixing and sorting is presented here for transport calculations. The interaction effects between fractions are included, especially the influence of fine fractions in the mixture on transport of coarser fractions. The model provides an agreement between measurements and calculations of transport rate and grain size distributions of poorly sorted mixtures within plus/minus a coefficient of two. Further, the present model is used for calculating the limited contribution of very fine fractions in sediment due to deficit of those fractions in the bed. Again, the compliance of the calculations of sediment transport according to measurements is achieved. The satisfactory agreement between the calculations of grain size distributions and measurements is also found.

Dissolution mass transfer of trapped gases in porous media: A correlation of Sherwood, Reynolds, and Schmidt numbers

The dissolution mass transfer of trapped phases in porous media is important in various fields, such as groundwater contamination, geological carbon sequestration, and geological energy storage. One of the difficulties in this study is the observation of the porous media interior during the dissolution mass transfer. Without the ability to monitor the process inside porous media, earlier studies were unable to measure the interfacial area of the trapped phase and thus were unable to calculate the mass transfer coefficient. In addition, complicating phenomena, such as two-stage dissolution and dissolution fingering, also affect the mass transfer process, in which it cannot be elucidated without observing to the porous media interior. In this present study, we investigated the dissolution mass transfer of various trapped phase in porous media at various fluid velocity by using micro-tomography. Therefore, the trapped phase interfacial area and mass transfer coefficient were successfully derived. In addition, the experimental setup was also designed to avoid the two-stage dissolution and dissolution fingering that could affect the mass transfer process significantly. As a result, we limit the observed phenomena to dissolution mass transfer processes alone. At the end, a mass transfer model based on Sherwood, Reynolds, and Schmidt numbers was developed. Because a mass transfer model that can be used for different trapped phases has never been developed, this developed model serves as an important reference for dissolution mass transfer model of trapped phases in porous media.

Are trapping data suited for home‐range estimation?

Modern home‐range estimation typically relies on data derived from expensive radio‐ or GPS‐tracking. Although trapping represents a low‐cost alternative to telemetry, evaluation of the performance of home‐range estimators on trap‐derived data is lacking. Using simulated data, we evaluated three variables reflecting the key trade‐offs ecologists face when designing a trapping study: 1) the number of observations obtained per individual, 2) the trap density and 3) the proportion of the home range falling inside the trapping area. We compared the performance of five home‐range estimators (MCP: Minimum Convex Polygon, LoCoH: Local Convex Hull, KDE: Kernel Density Estimation, AKDE: Autocorrelated Kernel Density Estimation, BicubIt: Bicubic Interpolation). We further explored the potential benefits of combining these estimators with asymptotic models, which leverage the saturating behavior of changes in the estimated home‐range area as the number of observations increases to improve accuracy, as well as different data‐ordering procedures. We then quantified the bias in home‐range size under the different scenarios investigated. The number of observations and the proportion of the home range within the trapping grid were the most important predictors of the accuracy and the precision of home‐range estimates. The use of asymptotic models helped to obtain accurate estimates at smaller sample sizes, while distance ordering improved the precision and asymptotic consistency of estimates. While AKDE was the best performing estimator under most conditions evaluated, bicubic interpolation was a viable alternative under common real‐world conditions of low trap density and area covered. A case study using empirical data from white‐tailed deer in Florida and another from jaguars in Belize demonstrated support for the findings of our simulation results. Although researchers with trap data often overlook home‐range estimation, our results indicate that these data have the capacity to yield accurate estimates of home‐range size. Trapping data can, therefore, lower the economic costs of home‐range analysis, potentially enlarging the span of species, researchers and questions studied in ecology and conservation.

Magnetization mechanism of a hybrid high temperature superconducting trapped field magnet

This paper studies the magnetization mechanism of a hybrid high temperature superconducting (HTS) trapped field magnet. To address the size limitation of traditional HTS bulk materials, hybridization between HTS-stacked ring magnets and HTS bulks is proposed here. A jointless HTS-stacked ring magnet is used to increase the trapped field area for HTS bulks. A hybrid HTS magnet with 90 mm in length and 60 mm in width was tested to provide a trapped field of 7.35 T in a field cooling magnetization. The paper focuses mainly on understanding the novel magnetization mechanism of this hybrid HTS trapped field magnet. A numerical model based on homogenized H formulation was used to compare with experimental results, and a good match was found. Our experimental and numerical study of the electromagnetic interaction between the HTS-stacked ring magnet and the HTS bulks reveals that there are two magnetization stages, and the magnetization speed differs in these two stages by a sing criterion: whether the HTS-stacked ring magnet is fully penetrated or not. This study confirms that hybridization helps to build large HTS trapped field magnets.