Mode Of Formation Research Articles

Influence of non-uniform flow on hysteresis effect of pitching hydrofoil

The hysteresis effect of pitching hydrofoil in uniform and non-uniform incoming flow are investigated theoretically and numerically. The numerical method is validated through the experimental results under steady uniform conditions. It has been shown that the simulation can capture the hysteresis effect of pitching hydrofoil. The added force caused by the pitching motion is an important factor of hysteresis phenomenon. When the sinusoidal periodical perturbations of incoming flow are carried, the hysteresis loop of lift coefficient curve are enlarged. According to the variation of the incoming flow, the lift coefficient curve are divided into four stages: S1(α+=5.0°∼α+=10.0°), S2(α+=10.0°∼α+=15.0°), S3(α-=15.0°∼α-=10.0°) and S4(α-=10.0°∼α-=5.0°). The flow structure and corresponding hydrodynamics of four stages under uniform and non-uniform conditions are compared and analyzed. Due to the non-uniform incoming velocity, the positive added lift increases in S1 stage and declines in S4 stage, thus leading to the increase of hysteresis loop. For the S2 stage, the “+” TEV is advanced because of the variational incoming flow. In S3 stage, the formation and development mode of “-” TEV are changed.

Modeling tourists’ preference between hotels and peer-to-peer (P2P) sharing accommodation: a pre- and post-COVID-19 comparison

PurposeWith the rapid development of sharing economy, travelers are facing choices between conventional hotels and the peer-to-peer sharing accommodation in urban tourism. The purpose of this study is to examine how travelers form their preferences in such choice situations and whether/how their preference formation mode would change with the COVID-19 pandemic.Design/methodology/approachA relative preference model was constructed and estimated for both domestic and outbound tourists, based on two waves of survey data collected before and after the COVID-19. The results of this study were compared to derive the evolution of preference formation patterns.FindingsA set of 15 key value attributes and personal traits was identified, together with their differential effects with the pandemic. Their divergent effects between domestic and outbound trips were also delineated. Based on these findings, the competitive edges and advantageous market profiles were depicted for both hotel and sharing accommodation sectors.Originality/valueThis study contributes to the knowledge of tourists’ preference between accommodation types and adds empirical evidences to the impact of the pandemic on tourist behavior patterns. Both hotel and sharing accommodation practitioners can benefit from the findings to enhance their competitiveness.

Spectral proper orthogonal decomposition analysis of trailing edge cutback film cooling flow

Spectral proper orthogonal decomposition (SPOD) is performed to identify the spatiotemporal coherent structures of trailing edge cutback film cooling flows. The analyzed data obtained from delayed-detached eddy simulation are validated against the experimental data first, followed by the extraction of SPOD modes and the reconstruction of flow fields using the SPOD modes. Results show that the flow topology of trailing edge cutback film cooling flows is mainly determined by the blowing ratio. At low blowing ratios, the vortex shedding phenomenon is captured by the first leading SPOD mode. Its mode shape corresponds to the bluff-body wake formation of the lip featured by spanwise coherent structures, which enhance the coolant–hot gas mixing process. At high blowing ratios, the vortex shedding phenomenon is represented by both the first and the second leading SPOD modes. In addition to the lip wake mode, the mode of the bluff-body wake formation of the coolant channel rib arises, whose mode shape is featured by transverse coherent structures. These structures enhance the mixing process between the coolant flows. As the blowing ratio increases, the dominating mode gradually transits from the lip wake mode to the rib wake mode. From the SPOD reconstruction study, the deterministic unsteadiness of vortex shedding is found to contribute to a substantial proportion of unsteady kinetic energy, especially at low blowing ratios. These findings help advance the understanding of trailing edge cutback film cooling flow.

Topography of the Young Galactic Disk: Spatial and Kinematic Patterns of Clustered Star Formation in the Solar Neighborhood

The accuracy in determining the spatial-kinematical parameters of open clusters makes them ideal tracers of the Galactic structure. Young open clusters (YOCs) are the main representatives of the clustered star formation mode, which identifies how most of the stars in the Galaxy form. We apply the Kriging technique to a sample of Gaia YOCs within a 3.5 kpc radius around the Sun and log(age) ≤ 7.5, as the age in years, to obtain Z(X, Y) and V Z (X, Y) maps. Previous work by Alfaro et al. has shown that Kriging can provide reliable results even with small data samples (N ∼ 100). We approach the 3D spatial and vertical velocity field structure of the Galactic disk defined by YOCs and analyze the hierarchy of the stellar cluster formation, which shows a rich hierarchical structure, displaying complexes embedded within each other. We discuss the fundamental characteristics of the methodology used to perform the mapping and point out the main results obtained in phenomenological terms. Both the 3D spatial distribution and the vertical velocity field reveal a complex disk structure with a high degree of substructures. Their analysis provides clues about the main physical mechanisms that shape the phase space of the clustered star formation in this Galactic area. Warp, corrugations, and high local deviations in Z and V Z appear to be intimately connected, in a single but intricate scenario.

Breakup dynamics of emulsion droplet and effects of inner interface

The size and the dispersibility of droplets are the significant factors that determine the performance in applications of the emulsion droplets, which are controlled by the breakup characteristics of interfaces. In this paper, a four-phase glass capillary device is used to generate three-layer wrapped (O 1 /O 2 /W/O 3 ) emulsion droplets stably, recording the evolution of interfaces to investigate the breakup characteristics of interfaces under different flow rates. Based on the breakup form of interfaces, the phase diagram which is recorded by the flow rate ratios ( α , β ) shows the distribution of different generation modes, including Jetting Tubing (JT), Dripping Tubing (DT), Dripping (D), Narrow Jetting (NJ) and Widen Jetting (WJ). The interfaces are recorded with time in different generation modes in this study, focusing on the generation details of DJ, D, and NJ mode, where the droplet generates with the stable periodic motion. The inner droplets do not influence the generation modes but provide the interactions of the interfaces in some cases, especially on the neck diameter of the outer interface. In DT mode, a larger flow rate ratio intensifies the fluctuation of the interface, while it pulls the neck of the inner interface and the outer one to the similar position along the flow direction. In NJ mode, the relation between prediction length and the experimental one follows a similar scaling law to single droplets with various coefficients. • Generation modes of four-phase emulsion droplets can be separated in the phase diagram by the flow rate ratios ( α , β ). • The inner phases have no effect on the distribution of formation modes, while the critical boundaries varies in each mode. • Inner droplets have influences on the characteristic parameters of each mode, including the neck diameter.

Influences of floating ice on the vertical water entry process of a trans-media projectile at high speeds

It is of great significance to study the hydrodynamic process of trans-media projectiles passing through ice-water mixture at high speeds for the application of weapons in low-temperature environments of high-latitude water areas during the winter. Based on the volume of fluid (VOF) method and the Schnerr-Sauer cavitation model, the processes of a projectile vertically entering water (without floating ice) and passing through ice-water mixture without collision with ice at different initial high speeds were studied. The influences caused by the ice on the cavity evolution, flow field characteristics, hydrodynamic and ballistic characteristics were analyzed. The results showed that the floating ice alters the volume of air that is sucked into the cavity by hindering the diffusion and contraction movement of the liquid at the gas-liquid interface, changing the degree of cavitation and the formation and development modes of the cavity. It causes a different evolution of the cavity shape, delays the cavity closure, and affects the hydrodynamic force and ballistic characteristics of the projectile ultimately. With increasing velocity, the influence of ice on cavity shape reduces, however, on projectile ballistics, it enhances. The results can provide some theoretical references for further application research on trans-media weapons in floating ice environments.

Programmed cell death associated with the formation of schizo-lysigenous aerenchyma in Nelumbo nucifera root.

Nelumbo nucifera (N. nucifera) is an important aquatic economic crop with high edible, medicinal, ornamental, and ecological restoration values. Aerenchyma formation in N. nucifera root is an adaptive trait to the aquatic environment in long-term evolution. In this study, light microscopy, electron microscopy, and molecular biology techniques were used to study the process of the aerenchyma development and cytological events in N. nucifera root and the dynamic changes of aerenchyma formation under the treatment of exogenous 21% oxygen, ethylene (ET), and ET synthesis i + nhibitor 1-methylcyclopropene (1-MCP). The results showed that programmed cell death (PCD) occurred during the aerenchyma formation in N. nucifera root. Plasmalemma invagination and vacuole membrane rupture appeared in the formation stage, followed by nuclear deformation, chromatin condensation and marginalization, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) detection was positive at this time. In the expansion stage of the aerenchyma development, cytoplasmic degradation and many vesicles appeared in the cytoplasm, and organelles began to degrade. Then the plasma membrane began to degrade, and the degradation of the cell wall was the last PCD step. After 21% oxygen was continuously filled in the rhizosphere environment of N. nucifera roots, the area of aerenchyma in N. nucifera roots was smaller than that in the control group. Moreover, ET induced the earlier occurrence of aerenchyma in N. nucifera root, but also, the area of aerenchyma became larger than that of the control. On the contrary, 1-MCP inhibited the occurrence of aerenchyma to some extent. Therefore, the formation of aerenchyma in N. nucifera root resulted from PCD, and its formation mode was schizo-lysigenous. A hypoxic environment could induce aerenchyma formation in plants. ET signal was involved in aerenchyma formation in N. nucifera root and had a positive regulatory effect. This study provides relevant data on the formation mechanism of plant aerenchyma and the cytological basis for exploring the regulation mechanism of plant aerenchyma formation.

Use of multifractal parameters to determine soil particle size distribution and erodibility of a physical soil crust in the Loess Plateau, China

Understanding the knowledge of multifractal analysis on particle size distribution (PSD) of soil physical crusts is indispensable for progressing soil surface erosion mode. In this study, hoeing tillage (20 cm long × 15 cm wide × 5 cm deep) were conducted to simulate classic tillage mode in Yangling, China to obtain physical crusts under artificial rainfall (60 mm h−1 intensity with three durations (5, 15, and 30 min)). We defined crusts formed in ridges as structural crust (Cst), formed by infiltration of runoff in hoes as sediment-containing depositional crust (Cscd), and formed by the extraction of runoff as sediment-free depositional crust (Csfd). Soil stratification methods were used to explore physical crust particle sorting. Results represented that the sand content of Cst, Cscd, and Csfd decreased, whereas clay and silt contents increased after rainfall compared to undisturbed soil. There was no significant difference between Cscd and Csfd under short rainfall duration. Three crust types became gradually concentrated in areas with higher density with increasing rainfall duration according to six common parameters in the generalised dimension spectrum (D0, D1, D2, D1/D0, Dv(D-10–D0), and Ds(D0–D10)). Multifractal singularity spectrum (α0, Av, Fv) showed that PSD was most symmetrical in Csfd, followed by Cscd and Cst. Erodibility index KEPIC was largest for Cst, followed by Csfd then Cscd. The relationship between KEPIC and multifractal parameters were significant. Spatial difference caused by tillage activities and rainfall events determine the heterogeneous formation mode, particle size distribution and erodibility of physical crust.

The characteristic length scales in direct mode of drop formation from the edges of spinning discs with different surface wetting characteristics

The characteristic length-scales responsible for primary and secondary drop size in direct droplet mode are probed using discs of different surface wettability through exposure controlled high resolution static imaging. The primary drop formation from the edge of a hydrophobic disc is found to be mechanistically different from its hydrophilic counterparts. The disc wetting factor (w) influences primary drop size only at low Weber number (We). A single mean primary/secondary drop size-We relationship represents discs of different surface characteristics. It points to insignificance of surface wettability. For hydrophilic discs the mean primary drop size and the mean incipient bulge size vary as We-0.47 and We-0.5 respectively, which hints at incipient bulge size dependence of primary drop size. The two capillary wave-based length scales tested as characteristic length scales for secondary drops show high size variability, which is a distinctive feature of secondary drops..

Main Controlling Factors and Formation Mode of Geothermal Anomaly in Eastern Chenghe Mining Area of Weibei Coalfield

Geothermal anomaly has gradually become a prominent issue affecting the efficient mining of coal with the depth of coal mining increasing in eastern Chenghe mining area of Weibei coalfield. Here, we comprehensively investigated the distribution characteristics of the present geothermal field, analyzed the main controlling factors, and constructed forming mode of geothermal anomaly by the temperature measurement in surface borehole and underground water, combined with coal-rock thermal conductivity test. The results show that the geothermal gradient ranged from 25.7°C/km to 54.3°C/km. The areas with geothermal gradient greater than 30°C/km accounted for 88.31%, and there was the highest gradient value in the southeast F1 fault zone. The heat flow was between 66.81 mW/m2 to 128.49 mW/m2, which belonged to the obvious high heat flow area. Under the action of the main controlling factors such as fault, fold, coal-rock thermal conductivity, and groundwater activity in the region, the geothermal gradient and geothermal heat flow values showed an increasing trend from northwest to southeast. According to the distribution characteristics of heat flow and the action mechanism of main controlling factors, the geothermal anomaly in the study area was finally divided into two forming modes, i.e., fault-deep circulating hot water uplifting type and coal seam heat resistance-fold type. The research provides guidance for the geothermal hazard prevention of coal mine and the rational development and utilization of geothermal resources.

Key Features and Factors behind Social Trust Formation in Ukraine

While social trust is seen as an essential factor in political, economic, and social progress in the world, its country-specific mode of formation remains underresearched. Considering Ukraine as a primary subject of analysis, this study attempts to define significant predictors that contribute to or undermine trust levels in the country. Special attention is paid to the impact of Ukraine’s conflict with Russia on the patterns of building social trust among Ukrainians. The analysis applies a multilevel model to World Values Survey (WVS) data from the pre-war and in-war periods (2011 and 2020). The findings of the study argue that the emergence of social trust is primarily influenced by political conditions in Ukraine and closely linked by Ukrainians to the issue of liberal democracy.

Formation Mechanism of a Coastal Zone Environment Collaborative Governance Relationship: A Qualitative Comparative Analysis Based on fsQCA.

The coastal zone is an area where terrestrial and marine ecosystems intersect. This region may be subject to outstanding environmental issues, as influenced by many stakeholders. Based on the framework of collaborative governance, the starting conditions for forming a coastal zone environment collaborative governance relationship are proposed as follows: coastal zone environment, balanced level of power and resources, superior-level government participation, and previous cooperation experience. The coastal environmental governance practices of 14 cities along the continental coastal zone of the East China Sea are selected as cases, in order to test the interactions between and influence mechanisms of the starting conditions. As qualitative comparative analysis (QCA), based on set theory and Boolean algebra, is a popular tool to explain complex collaboration situations in small-N cases; and as fuzzy-set qualitative comparative analysis (fsQCA) allows for fine classification of the membership degree (where the condition can be allocated any number between 0 and 1), we use fsQCA to analyze the collaborative governance relationships. The results of the analysis demonstrate that three combination configurations promote the formation of medium–high intensity collaborative governance relationships: high balance level of power and resources × high previous cooperation experience, high pollution of coastal zone environment × high balance level of power and resources × low superior-level government participation, and high pollution of coastal zone environment × high superior-level government participation × high previous cooperation experience. Based on this conclusion, we determine three types of relationship formation modes: wheel-, echo state network-, and umbrella-shaped modes. Notably, under certain conditions, superior-level government participation is not necessary for the formation of a medium–high intensity collaborative governance relationship.

Biomechanical Evaluation of a Novel Double-Strand (Looped) Polyamide Monofilament Suture for Canine Flexor Tendon Repair

Objective: Determine the influence of a novel looped polyamide suture on the biomechanical properties and gap formation of repaired canine flexor tendons. Study Design: Tendons were assigned to 3 groups (n=12/group). Following transection, tendons were repaired with a Kessler pattern using monofilament polypropylene, Kessler pattern using looped polyamide suture and a Kessler pattern using looped polyamide augmented with a continuous Epitendinous Suture (ES) representing groups 1, 2, and 3 respectively. Constructs were tested to simulate clinical failure. Yield, peak and failure loads, loads at -1 and 3mm gap formation and failure modes were analyzed. Results: Looped polyamide suture is equivalent to monofilament polypropylene using a Kessler core pattern. Looped polyamide suture augmented with a running ES significantly increased yield, peak and failure loads by 3.2x, 3.0x and 2.6x respectively, compared to core suture use alone. Use of an ES required significantly greater force to cause 3mm gap formation while reducing occurrence of gapping in tested constructs. Mode of failure differed among experimental constructs. Conclusion: Looped polyamide suture is equivalent to monofilament polypropylene in the same pattern. Our results support the addition of ES augmentation, a simple technique modification that demonstrates substantially improved repair strength while reducing the occurrence of gapping between tendon ends. Future in-vivo studies investigating effect of suture placement on tendinous healing, blood supply, and glide function are warranted.

VINTERGATAN IV: Cosmic phases of star formation in Milky Way-like galaxies

ABSTRACT The star formation history of a galaxy is modulated by a plethora of internal processes and environmental conditions. The details of how these evolve and couple together are not fully understood yet. In this work, we study the effects that galaxy mergers and morphological transformations have on setting different modes of star formation at galactic scales and across cosmic time. We monitor the global properties of vintergatan, a 20 pc resolution cosmological zoom-in simulation of a Milky Way-type galaxy. Between redshifts 1 and 5, we find that major mergers trigger multiple starburst episodes, corresponding to a tenfold drop of the gas depletion time down to 100 Myr. Bursty star formation is enabled by the emergence of a galactic disc, when the rotational velocity of gas starts to dominate over its velocity dispersion. Coherent motions of gas then outweigh disordered ones, such that the galaxy responds to merger-induced forcings by redistributing large amounts of gas towards high densities. As a result, the overall star formation rate (SFR) is enhanced with an associated decrease in the depletion time. Before redshift 5, mergers were expected to be even more frequent. However, a more turbulent interstellar medium is incapable of reacting in such a collective manner so as to spark rapid star formation. Thus, a constant long depletion time of 1 Gyr is kept, along with a low, but gradually increasing SFR. After the last major merger at redshift 1, vintergatan spends the next 8 Gyr evolving secularly. It has a settled and adiabatically growing disc, and a constant SFR with gas depletion times of 1–2 Gyr. Our results are compatible with the observed rapid transition between different modes of star formation when galaxies leave the main sequence.

Phenolic lipid derived coordination polymer nanocomposites: Synthesis, characterization and surface protective coating applications

Fabrication of renewable-resource (Cardanol, Col) based nanocomposite films/coatings has opened up a new path in the development of a sustainable and environment-friendly polymeric material with prodigious attention. In the present work, Co(II) and Ni(II) coordinated Col nanocomposites (Col-CPU/CoO and Col-CPU/NiO) have been fabricated via following an easy, cost-effective, in-situ approach. These materials have been used to develop mechanically robust, anti-corrosive, antibacterial thin films and coatings against gram-positive (S.aureus and B.subtilis) and gram-negative (E.coli and P.aeruginosa) bacteria. Spectral techniques were used to deduce the mode of formation and geometry of synthesized nanocomposites. The prepared nanocomposites of Co(II) and Ni(II) demonstrate improved thermal stability and flame retardant behavior with the aid of metal nodes compared to the pristine polymer. The developed films displayed amorphous behavior with a layered pattern and nano-porous morphology over the surface of the nanocomposites which was confirmed by the Brunauer-Emmett-Teller (BET) studies. Surface wettability studies revealed hydrophobic and superhydrophobic surfaces with a contact angle of 143° of Col-CPU/CoO and 158° of Col-CPU/NiO, respectively. Superior physicomechanical properties of metal nanocomposites such as scratch hardness, crosshatch, gloss, bend test, and impact resistance, compared with the pristine polymer point to a uniform distribution of metal-coordinated networks. Therefore, this cost-effective and sustainable approach can be utilized for the development of polyurethane (PU) nanocomposites that could be employed as thermally stable, fire-retardant, anti-corrosive, antibacterial films and coatings in different fields of applications.

Advanced Hydrogel systems for mandibular reconstruction

Mandibular defect becomes a prevalent maxillofacial disease resulting in mandibular dysfunctions and huge psychological burdens to the patients. Considering the routine presence of oral contaminations and aesthetic restoration of facial structures, the current clinical treatments are however limited, incapable to reconstruct the structural integrity and regeneration, spurring the need for cost-effective mandibular tissue engineering. Hydrogel systems possess great merit for mandibular reconstruction with precise involvement of cells and bioactive factors. In this review, current clinical treatments and distinct mode(s) of mandible formation and pathological resorption are summarized, followed by a review of hydrogel-related mandibular tissue engineering, and an update on the advanced fabrication of hydrogels with improved mechanical property, antibacterial ability, injectable form, and 3D bioprinted hydrogel constructs. The exploration of advanced hydrogel systems will lay down a solid foundation for a bright future with more biocompatible, effective, and personalized treatment in mandibular reconstruction.

Self-assembled Natural Product-based Carrier-free Nanoplatforms for Efficient Bioactivity

Natural products featured by an abundant molecule skeleton and structural complexity exhibit extensive pharmacological or biological activities. Thus, natural active ingredients are an important source of drug research and development. However, the inherent defects, including low solubility, low bioavailability, and unacceptable off-target toxicity, affect their development into clinical drugs. Recently, carrier-free supermolecule nanodrugs have attracted considerable attention. These nanodrugs are self-assembled by pure drugs mainly through hydrophobicity, hydrogen bond, π-π stacking, and electrostatic interaction, which possess a high drug loading capability, enhanced water solubility of the drugs, and synergistic therapeutic efficacy. In this review, natural product-based carrier-free nanoplatforms with self-assembly for efficient bioactivity were examined. These self-assembled natural products included triterpenoids, alkaloids, flavonoids, and anthraquinones. Moreover, the morphology of the formed nanoplatforms could be a nanosphere, nanofiber, nanorod, or fibrillar network, and they could exhibit several bioactivities, such as antitumor, anti-inflammatory, immunoregulation, and liver protection. Briefly, we analyzed the types and sources, formation mechanism, biological activity, and mode of action of the nanomedicine, and discussed the future of this field. We believe this review would provide a landscape of natural product-based carrier-free nanoplatforms.

Interfacial strength between ice and sediment: A solution towards fracture-filling hydrate system

Fracture-filling natural gas hydrates (NGH) are widely distributed in marine shallow clayey-silt sediment, and usually develop in forms of nodular, veins, layers, and massive pure hydrate. Interactions between these hydrate individuals and their surrounding sediment are crucial to evaluate potential submarine geohazards related to fracture-filling NGH systems. In this paper, we develop a novel apparatus to detect interfacial strength between hydrate individual and its host sediment. Shear strengths of three typical substances (i.e., massive pure hydrate, hydrate-saturated sediment, and hydrate-to-sediment interfaces) in fracture-filling NGH systems are examined and compared comprehensively by taking ice as substitute. Possible failure patterns of the fracture-filling NGH systems are discussed, and a tree-like model is proposed to describe formation mode and failure patterns of the fracture-filling NGH reservoirs. The results indicate that the load–displacement curves and shear surface characteristics of the ice-sediment interface differs significantly from those of the pure ice and ice-bearing sediment. The load–displacement curves of the ice-sediment interfacial specimens show double-peak loading characteristics, with multiple interlaced cracks on the shear surface. Additionally, the strength of the ice-sediment interfacial specimens is sensitive to shear rate, and decreases with increasing shear rate. These double-peak failure behaviors and rambling cracks in the shear surface are attributed to the nonlinear contact interfaces and two transitional sub-systems (i.e., silt-bearing ice and ice-bearing silt) in the specimens.

Interaction between Al<sup>3+</sup> and Poly(acrylic acid) (PAA) in Aqueous Solution—Formation Modes for the Al–PAA Complexes

Interaction between Al<sup>3+</sup> and Poly(acrylic acid) (PAA) in Aqueous Solution—Formation Modes for the Al–PAA Complexes

Unraveling the physiologic paradoxes that underlie exercise prescription for stress fracture prevention.

The effects of exercise on stress fracture risk are paradoxical. Exercise can promote both bone formation and resorption, which in turn, can reduce and increase risk of stress fractures, respectively. We review classic and current literature that suggests that the processes that underlie these responses to exercise are distinct. Bone remodeling involves osteoclastic resorption of fatigue-damaged bone, coupled with subsequent bone deposition to replace the damaged tissue. Bone modeling involves the independent action of osteoblasts and osteoclasts forming or resorbing bone, respectively, on a surface. In the formation mode, modeling results in increased bone stiffness, strength, and resistance to fatigue. Both the remodeling and modeling responses to exercise require significant time for newly deposited bone to fully mineralize. We propose that recognizing these two distinct physiologic pathways and their related time courses reveals the theoretical basis to guide exercise prescription to promote bone health during periods of heightened stress fracture risk. Such guidance may include minimizing rapid increases in the duration of repetitive exercises that may cause fatigue damage accrual, such as long-distance running and marching. Rather, limiting initial exercise characteristics to those known to stimulate bone formation, such as short-duration, moderate-to-high impact, dynamic, and multidirectional activities with rest insertion, may increase the fatigue resistance of bone and consequently minimize stress fracture risk.