Non-steady State Research Articles

An Analytical Study on Trustability of Prescribed Slope Inclinations in Design Criteria

In order to investigate trustability of prescribed slope inclinations in design criteria, slope stability analyses were performed on the assumed two embankment sections. Factors of safety against dry condition for the section of 10m high and slope inclination of 1:2 and for the other section of 5m high and slope inclination of 1:1.5 were 1.93 and 2.24 respectively and those values were greater than the design criterion value of 1.50. Factors of safety which were computed through seepage analyses for steady state condition were 1.59 for the section of 10m high and 1.93 for the other section and those values were greater than design criterion value of 1.30. Non-steady state analyses under the same rainfall intensity for the steady state condition were also performed to compare with steady state analyses and it can be seen that factor of safety for the non-steady state condition was converged to the value for the steady state condition as time elapsed. Stability analyses of using piezometric line which were located on the top line of the sections were performed and computed values of factor of safety were 1.20 for the section of 10m high and 1.59 for the other section respectively and it could be seen that the factor of safety for the section of 10m is less than the criterion value of 1.30. According to the results of this study, it can be seen that the slope inclination of 1:1.5 for the slope heights less than 5m and the slope inclination of 1:2.0 for the slope heights between 5m to 10m were safe enough under dry condition and rainfall condition. Nevertheless it can be concluded that slope stability analysis should be performed for the slope over 10m high and with ground water table near the surface of the slope because the factor of safety for that situation was less than the design criterion value.

Elastohydrodynamic Squeeze-film Interaction in Synovial Joints with Nanofluid Lubrication

New lubrication events can be predicted using improved pathological non-Newtonian physiological fluids coupled to phospholipid-based bilayers in variable time-dependent magnetic fields under random non-steady conditions. In this study, we investigated nanofluid lubrication systems for synovial joints. The particles of PSPMA-g-HSNPs were used as nanoparticles. The hydrodynamic interaction between the knee bones separated by a nanofluid film was considered here for various nanofluid concentrations. The simulation indicated solid mechanics on the bones being pushed by 45 kg-force. The lubricant layer was squeezed by the approaching bones, which increased the pressure on the lubricant. The calculated maximum lubricant pressure and the change in film height with time were compared to analytical solutions. The results showed that the application of the nanofluid technology on non-conventional lubrication systems for synovial joints was feasible. Finally, we also found that with an increase in the nanoparticle concentration, the maximum pressure on the squeeze film decreased, which introduced a new type of bio-fluid to non-conventional lubrication systems for synovial joints.

Exploration of non-trivial relations for the non-steady state nucleation rate: usefulness of the elliptic theta functions for its experimental estimations

It is known that the non-steady state nucleation rate can be expressed as the product of the steady state nucleation rate and an elliptic theta function. However, there has been no research where rich mathematical properties of the elliptic theta functions were utilized to analyze the non-steady state nucleation processes. In this paper, we achieved two objectives by using the properties. The first one is to derive non-trivial relations for the non-steady state nucleation rate by using the rich mathematical properties of the elliptic theta functions, which could not be discovered in the conventional classical nucleation theory because of its complexities. The second one is to find solutions to two problems by solving a difference equation for the non-steady state nucleation rate: (i) it requires a large amount of effort and cost to estimate the time evolution of the non-steady state nucleation rate under some special conditions, and (ii) it is impossible to measure the non-steady state nucleation rate under some special cases. It is shown that our result help reduce the estimation cost of the non-steady state nucleation rate and makes mechanical estimation of the non-steady state nucleation rate possible from the past to the future.Article highlightsNon-trivial relations for the non-steady state nucleation rate are found from the mathematical properties of the elliptic theta functions.It is shown that our result help reduce the estimation cost of the non-steady state nucleation rate.It is shown that our result makes mechanical estimation of the non-steady state nucleation rate possible from the past to the future.

PSII-B-20 Altering the Particle Size of Supplemental Zeolite (Clinoptilolite) in Finishing Cattle Diets: Manure Characteristics and Ammonia Emissions

Abstract A potential strategy to limit ammonia (NH3) emissions from feedlots is the feeding of supplemental clinoptilolite (CLN), which has a high affinity for ammonium (NH4+). The particle size of CLN could influence its efficacy in binding NH4+ in the rumen and manure. Therefore, our objective was to determine the effects of feeding CLN (2% of diet DM) of two different particle sizes (30 and 40 µm) on manure N profile and NH3 emissions. Six beef heifers were used in a replicated 3 × 3 Latin square design with 21 d periods. Dietary treatments were: 1) finishing ration with no supplement (CON), 2) CON + 30-µm CLN (CL-30), and 3) CON + 40-µm CLN (CL-40). Grab fecal and spot urine samples were collected (d 19 to 21) for analysis. To determine NH3 emissions, six rectangular vented, non-steady state, closed chambers interfaced with a Fourier Transform Infrared Spectroscopy analyzer were used. Soil was added to chambers to a depth of 10 cm before addition of manure and incubated over a 7-d period. Data were analyzed using SAS. There was no diet effect (P ≥ 0.78) on urinary total nitrogen (N) and urea-N concentrations. However, urinary NH3-N concentration, which was less (P = 0.03) for CON than CL-40 heifers did not differ between CON and CL-30 heifers. Fecal N concentration, which tended to greater (P = 0.07) for CL-30 than CL-40 heifers did not differ between CON and CL-40 heifers. However, there was no diet effect (P = 0.25) on fecal NH3-N concentration. Ammonia emissions, which were less (P = 0.02) for manure from CL-40 than CL-30 heifers, did not differ between CON and CL-30 heifers during the first 48 h of incubation. In summary, feeding CL with different particle sizes resulted in changes in the manure N profile and NH3 emissions.

Global well-posedness of fourth-order Petrovsky equation with weak and strong damping terms

In this paper, a semilinear fourth-order Petrovsky equation with nonlinear weak damping term and linear strong damping term is considered in the frame of the potential well. We prove the existence and uniqueness of the global strong solution with sub-critical initial energy. In addition, we obtain the global existence, asymptotic behaviour and finite time blowup for the weak (non-steady state) solution with a critical initial energy level.

From the multiterm urn model to the self-exciting negative binomial distribution and Hawkes processes.

This paper considers a multiterm urn process that has a correlation in the same term and temporal correlation. .The objective is to clarify the relationship between the urn model and the Hawkes process. Correlation in the same term is represented by the Pólya urn model and the temporal correlation is incorporated by introducing the conditional initial condition. In the double scaling limit of this urn process, the self-exciting negative binomial distribution process, which is a marked Hawkes process, is obtained. In the standard continuous limit, this process becomes the Hawkes process, which has no correlation in the same term. The difference is the variance of the intensity function in that the phase transition from the steady to the nonsteady state can be observed. The critical point, at which the power-law distribution is obtained, is the same for the Hawkes and the urn processes. These two processes are used to analyze empirical data of financial default to estimate the parameters of the model. For the default portfolio, the results produced by the urn process are superior to those obtained with the Hawkes process and confirm self-excitation.

Transpiration Induced Changes in Atmospheric Water Vapor δ18O via Isotopic Non-Steady-State Effects on a Subtropical Forest Plantation

Accurate simulation of oxygen isotopic composition (δ18OT) of transpiration (T) and its contribution via isotopic non-steady-state (NSS) to atmospheric water vapor δ18O (δ18Ov) still faces great challenges. High-frequency in-situ measurements of δ18Ov and evapotranspiration (ET) δ18O were conducted for two summer days on a subtropical forest plantation. δ18O of xylem, leaf, and soil water at 3 or 4-h intervals was analyzed. Leaf water δ18O and δ18OT were estimated using the Craig and Gordon (CG), Dongmann and Farquhar–Cernusak models, and evaporation (E) δ18O using the CG model. To quantify the effects of δ18OT, δ18OE, and δ18OET on δ18Ov, T, E, and ET isoforcing was calculated as the product of T, E, and ET fluxes, and the deviation of their δ18O from δ18Ov. Results showed that isotopic steady-state assumption (SS) was satisfied between 12:00 and 15:00. NSS was significant, and δ18OT was underestimated by SS before 12:00 and after 18:00. The Péclet effect was less important to δ18OT simulation than NSS at the canopy level. Due to decreasing atmospheric vertical mixing and the appearance of the inversion layer, contribution from positive T isoforcing increased δ18Ov in the morning and at night. During the daytime, the contribution from positive T isoforcing increased first and then decreased due to strong vertical mixing and variability in T rate.

Estuarine water quality: One-dimensional model theory and its application to a riverine subtropical estuary in Florida

In this study, analytical solutions were found for nutrients and phytoplankton in an idealized one-dimensional estuary with tidally averaged conditions. Steady forcing conditions and first order kinetics were assumed for freshwater inflow, nutrients, and algal loading input. These analytical solutions consist of two parts, a steady state solution and a non-steady state solution. The steady state solution was determined for a typical advection-dispersion-reaction equation for a nonconservative constituent. For phytoplankton, the non-steady solution has exponential growth or decay depending on the difference between the net growth rate (μnet) and the flushing rate (f). When μnet is greater than f, exponential growth or algal bloom could occur; otherwise, it would be an exponential decay over the time scale of 1/(f- μnet). The steady state solution for phytoplankton predicted the chlorophyll maximum and its location, which would move downstream with increasing freshwater inflows, a phenomenon observed in field studies (Doering et al., 2006; Valdes-Weaver et al., 2006). When applied to the Caloosahatchee River Estuary, a shallow riverine estuary in southwest Florida, the steady state solution for phytoplankton was able to reasonably reproduce the general shape of observed longitudinal phytoplankton distribution. Consistent with the findings of a recent box model study (Sun et al., submitted), this one-dimensional model suggests that there may be important contributions from external loading of phytoplankton to downstream phytoplankton biomass. This finding can inform future improvement of more complex numerical models of estuarine eutrophication as well as practical water management strategies.

Estimating the long-term slip rate of active normal faults: The case of the Paganica Fault (Central Apennines, Italy)

The footwall of the surface rupturing Paganica normal fault, the source of the 2009 L’Aquila earthquake (Mw 6.1) in the Central Apennines (Italy), was investigated using integrated geological and geomorphological approaches. The aim was to constrain the active tectonics by studying the Raiale River that orthogonally crosscuts the fault trace, where it provides a useful geomorphological marker of long-term fluvial incision and footwall uplift. Using morphostratigraphy and paleomagnetic analysis, the Plio–Pleistocene morphotectonic evolution of the area was reconstructed, comprising an ancient continental basin and paleolandforms that predate the footwall incision. Starting from the Late Early Pleistocene–Middle Pleistocene, fluvial dissection was mainly due to marked river downcutting triggered by significant activity of the Paganica Fault, which caused progressive base-level lowering. The Raiale River downcutting formed five Middle–Late Pleistocene fluvial terraces, that, along with absolute Optically Stimulated Luminescence (OSL) dating, allowed the identification of paleolongitudinal profiles with a diverging downstream configuration. Terrace dating yielded a minimum incision rate of 0.25 ± 0.02 mm/a, which only partially compensates the footwall uplift and can thus be considered as a minimum value for the Paganica Fault throw rate, which could reach up to ~0.45 mm/a. In parallel, using terrestrial cosmogenic nuclides, a denudation rate of 0.02–0.04 mm/a was measured on the summit of the footwall block. This denudation is in keeping with the drainage incision, suggesting a non-steady state for the fault footwall topography and a dominance of relief growth. Last, the analysis of the modern Raiale River longitudinal profile denoted an ungraded status, with two main knickzones that we interpret as transient forms due to tectonic perturbations, likely triggered by activity of the Paganica Fault during the end Early Pleistocene and the Late Pleistocene. Considering the 2009 L’Aquila earthquake coseismic rupture, we observe that the younger transience on the Raiale River longitudinal profile, if it is of tectonic origin, could have only been produced by much larger seismic events (i.e., Mw > 6.5) than those documented in the area by paleoseismological investigations. The collective results confirmed that in the Central Apennines, conditions of dynamic equilibrium are often not met, and that the persistence of transient perturbations induced by tectonics should be accounted for.

Precise prediction of photothermally induced irreversible bending deformation based on non-uniform thermal expansion of layer-structure films

Although photothermally induced self-bending films based on nonuniform thermal expansion are created, heat transfer and shape-deformation procedures are not investigated very well, limiting the understanding of such complicated behavior and the achievement of precise shape control. Here, thermally expanded microspheres (TEMs) were added into polydimethylsiloxane (PDMS) to create active layers as PDMS-TEM single-layer films that were attached onto pure PDMS passive layer to create PDMS/PDMS-TEM bi-layer films subsequently. After heating, TEMs in the film undergo phase transition and present irreversible thermal expansion, driving deformation of films. Combined with steady-state (uniform heating) deformation simulations and experiments, a deformation model was established before a non-steady state (light irradiation) heat transfer model was set up to simulate the heat transfer process of films under light irradiation. Then the temperature distribution was coupled with the deformation model to simulate the photothermally induced deformation of the samples. The PDMS-TEM single-layer films also presented bending deformation under illumination due to the non-uniform thermal expansion caused by temperature gradient. For bi-layer films, different degrees of thermal expansion between two layers lead to bending deformation. The films with TEM concentration of 30 wt% can achieve great deformation, and the bending curvature was 0.07 mm−1. The geometric parameters including thickness, layer thickness ratio and aspect ratio had little effect on deformation degrees of the films. Deformation mode was varied with aspect ratio. A long side bending and diagonal bending were achieved in bi-layer films at aspect ratios of 7:1 and 1:1. In combination with experimental results, the heat transfer model and deformation model were constructed to demonstrate the complex deformation process, which provides guidance for the structural design of the photothermally induced shape-changing films in practical applications.

Non-steady state heat transport: a practical case of a microscopic energy balance in a vegetable

In this paper, the analytical and numerical solutions of a non-steady state mathematical model are developed and analyzed. The mathematical model development of a non-steady state heat transport for a one-dimensional system is shown, and the analytical solution of the model is presented. The numerical solution of the model, using the finite element method (FEM), is compared to its analytical solution, proving its consistency. One of the advantages of using numerical tools is that more complex solutions can be obtained, even if the corresponding analytical solution does not exist or is not known, which is useful for engineering students. To demonstrate the applications and possibilities of this work, it is shown that changing the boundary conditions, geometry, or dimension in the system and the mathematical model, it can be solved through a numerical solution method. This is easier and more comprehensive for students rather than facing the complexity of the analytical solutions. The paper shows that it is possible to use the FEM in a university teaching context to complementarily explain the underlying physical phenomena of an engineering problem, here applied to a heat transfer problem in a vegetable.

Mesoscale modeling of chloride transport in unsaturated concrete based on Voronoi tessellation

This paper presents a three-dimensional mesoscale model of concrete with random packing of spherical aggregates, in which the mortar and interfacial transition zone (ITZ) are discretized based on the Voronoi tessellation. A non-steady state model is developed to simulate the chloride diffusion-sorption behavior, with different water diffusion coefficients for wetting and drying processes, respectively. The results confirm general suitability of Voronoi diagram in element mesh generation. Large deviations in the chloride profile predictions may be generated if a single value or unified equation is used for the water diffusion coefficient of both wetting and drying processes. The peak chloride concentration increases with the exposure time. The overall chloride concentration increases as the porosity increases and the tortuosity decreases. Sensitivity analyses suggest that, compared with porosity and constrictivity, tortuosity has a more significant effect on the overall chloride concentration.

A proposal to identify the maximal metabolic steady state by muscle oxygenation and VO2max levels in trained cyclists

PurposeNear-infrared spectroscopy (NIRS) sensors measure muscle oxygen saturation (SmO2) as a performance factor in endurance athletes. The objective of this study is to delimit metabolic thresholds relative to maximal metabolic steady state (MMSS) using SmO2 in cyclists.MethodsForty-eight cyclists performed a graded incremental test (GTX) (100 W-warm-up followed by 30 W min) until exhaustion. SmO2 was measured with a portable NIRS placed on the vastus lateralis. Subjects were classified by VO2max levels with a scale from 2 to 5: L2 = 45–54.9, L3 = 55–64.9, L4 = 65–71, L5 = > 71, which represent recreationally trained, trained, well-trained, and professional, respectively. Then, metabolic thresholds were determined: Fatmax zone, functional threshold power (FTP), respiratory compensation point (RCP), and maximal aerobic power (MAP). In addition, power output%, heart rate%, VO2%, carbohydrate and fat consumption to cutoff SmO2 point relative to MMSS were obtained.ResultsA greater SmO2 decrease was found in cyclists with > 55 VO2max (L3, L4 and L5) vs. cyclists (L2) in the MMSS. Likewise, after passing FTP and RCP, performance is dependent on better muscle oxygen extraction. Furthermore, the MMSS was defined at 27% SmO2, where a non-steady state begins during exercise in trained cyclists.ConclusionA new indicator has been provided for trained cyclists, < 27% SmO2 as a cut-off to define the MMSS Zone. This is the intensity for which the athlete can sustain 1 h of exercise under quasi-steady state conditions without fatiguing.

Stress Heterogeneity as a Driver of Aseismic Slip During the 2011 Prague, Oklahoma Aftershock Sequence

AbstractThe interaction of aseismic and seismic slip before and after an earthquake is fundamental for both earthquake nucleation and postseismic stress relaxation. However, it can be difficult to determine where and when aseismic slip occurs within the seismogenic zone because geodetic techniques are limited to detecting moderate to large slip amplitudes or long duration small slip amplitudes. Here, we use repeating earthquakes (earthquakes that re‐rupture the same fault patch) as a proxy for aseismic slip during the 2011 Prague, Oklahoma earthquake sequence. We find that aseismic slip in the Prague earthquake sequence occurs both within the granitic basement and the overlying sedimentary rocks. The repeating earthquakes show that patches of aseismic slip are mostly located at fault intersections. These fault intersections hosted possible mainshock slip, abundant aftershocks, and afterslip. We estimate that ∼40% of the aftershocks are driven by afterslip. We interpret that aseismic slip occurs at fault intersections where stress heterogeneity creates patches of lower stress that are stable within a nonsteady state, rate‐state framework.

Generalization on Entropy-Ruled Charge and Energy Transport for Organic Solids and Biomolecular Aggregates.

Herein, a generalized version of the entropy-ruled charge and energy transport mechanism for organic solids and biomolecular aggregates is presented. The effects of thermal disorder and electric field on electronic transport in molecular solids have been quantified by entropy, which eventually varies with respect to the typical disorder (static or dynamic). Based on our previous differential entropy (hs)-driven charge transport method, we explore the nonsteady carrier energy flux principle for soft matter systems from small organic solids to macrobiomolecular aggregates. Through this principle, the synergic nature of charge and energy transport in different organic systems is addressed. In this work, entropy is the key parameter to classify whether the carrier dynamics is in a nonsteady or steady state. Besides that, we also propose the formulation for unifying the hopping and band transport, which provides the relaxation time–hopping rate relation and the relaxation time–effective mass ratio. The calculated disorder drift time (or entropy-weighted carrier drift time) for hole transport in an alkyl-substituted triphenylamine (TPA) molecular device is 9.3 × 10–7 s, which illustrates nuclear dynamics-coupled charge transfer kinetics. The existence of nonequilibrium transport is anticipated while the carrier dynamics is in the nonsteady state, which is further examined from the rate of traversing potential in octupolar molecules. Our entropy-ruled Einstein model connects the adiabatic band and nonadiabatic hopping transport mechanisms. The logarithmic current density at different electric field-assisted site energy differences provides information about the typical transport (whether trap-free diffusion or trap-assisted recombination) in molecular devices, which reflects in the Navamani–Shockley diode equation.

Blood supply interventions during disasters: Efficiency measures and strategies to mitigate volatility

In this study, we examine three types of blood supply interventions during disasters; namely, interventions related to recruitment, propensity to donate and retention, and reduction of regeneration time. Through a stylized model, we characterize the equivalence of each of the interventions in meeting blood bank targets while assuming a steady state. We then introduce an effort parameter which determines the difficulty of implementing an intervention and consequently when each should be used. We find that propensity to donate and retention interventions are more effective when donation rate is low, while reduction of regeneration time is an efficient intervention when donation rate is high. However, physiological and ethical limitations mean that the latter can only be used up to a certain degree for intermediate donation rate values depending on the effort parameters. Therefore, recruitment interventions become the preferred intervention by default when donation rate is high. We extend this analysis to a disaster’s non-steady state case by using an iterative calculation procedure and show that the equivalence among interventions continue to hold. Further, we devise three strategies that blood banks can use to manage blood donation during disasters: (1) the fixed (2) dynamic, and (3) threshold donation rate strategies. These work on the premise that blood banks have control over the expected number of donations through its use of interventions. By defining what it means to deviate from the steady state, we show that the standard fixed donation rate strategy found in literature leads to increased volatility both during and after disasters. The dynamic donation rate strategy mitigates this volatility but requires daily usage of interventions. This is solved by the threshold donation rate strategy which only uses interventions when the day’s donations are expected to deviate from the target. Lastly, we conduct a simulation study using data for two countries and find that the strategies work better for more mature blood banks with higher pre-disaster fill-rates.

Gas transfer model for a multistage vortex aerator: A novel oxygen transfer system for dissolved oxygen improvement

A novel aerator for enhancing the oxygen transfer rate and efficiency, named multistage vortex aerator (MVA), was developed. It uses vortex flow in repeated stages to increase the gas-liquid interfacial area and to decrease the thickness of the stagnant layer at the interface between the two phases. The basic characteristics of oxygen transfer using this aerator were investigated using the American Society of Civil Engineers standard procedure. The MVA could rapidly transfer oxygen to water to a concentration higher than 40 mg/L in 60 min owing to the effect of high purity oxygen, additional pressure induced by water and gas, and vortex flow dynamics. A gas transfer model was developed for describing the non-steady state operation of the aerator. This model is based on the mass and molar balances of oxygen in gas and water. It could successfully simulate the DO change inside the aerator. This study can help better understand the oxygen transfer mechanism and evaluate the performance of the new aerator at the various temperatures, pressures, and gas compositions found in diverse environmental systems.

Impact of High Methane Flux on the Properties of Pore Fluid and Methane-Derived Authigenic Carbonate in the ARAON Mounds, Chukchi Sea

We investigated the pore fluid and methane-derived authigenic carbonate (MDAC) chemistry from the ARAON Mounds in the Chukchi Sea to reveal how methane (CH4) seepage impacts their compositional and isotopic properties. During the ARA07C and ARA09C Expeditions, many in situ gas hydrates (GHs) and MDACs were found near the seafloor. The fluid chemistry has been considerably modified in association with the high CH4 flux and its related byproducts (GHs and MDACs). Compared to Site ARA09C-St 08 (reference site), which displays a linear SO42- downcore profile, the other sites (e.g., ARA07C-St 13, ARA07C-St 14, ARA09C-St 04, ARA09C-St 07, and ARA09C-St 12) that are found byproducts exhibit concave-up and/or kink type SO42- profiles. The physical properties and fluid pathways in sediment columns have been altered by these byproducts, which prevents the steady state condition of the dissolved species through them. Consequently, chemical zones are separated between bearing and non-bearing byproducts intervals under non-steady state condition from the seafloor to the sulfate-methane transition (SMT). GH dissociation also significantly impacts pore fluid properties (e.g., low Cl-, enriched δD and δ18O). The upward CH4 with depleted δ13C from the thermogenic origin affects the chemical signatures of MDACs. The enriched δ18O fluid from GH dissociation also influences the properties of MDACs. Thus, in the ARAON Mounds, the chemistry of the fluid and MDAC has significantly changed, most likely responding to the CH4 flux and GH dissociation through geological time. Overall, our findings will improve the understanding and prediction of the pore fluid and MDAC chemistry in the Arctic Ocean related to CH4 seepage by global climate change.

Validation of Accelerometer-Based Estimations of Energy Expenditure During High-Intensity Interval Training

Accelerometers are used to assess free-living physical activity (PA) and energy expenditure (EE). Energy expenditure estimation algorithms have been calibrated using steady-state exercise. However, most free-living PA is not steady-state. Objective: The purpose of this study was to discern the differences between criterion-measured and accelerometer-estimated EE (kCals) during a non-steady-state High-Intensity Interval Training (HIIT) session. Methods: Recreationally active adults (N=29, 18-30 years) completed one of two HIIT protocols. Each participant wore ActiGraph GT3X+ accelerometers on the right hip and non-dominant wrist while EE was measured using portable indirect calorimetry. Data analysis was conducted using custom R scripts and bias [95% CIs] to determine significant differences between indirect calorimetry and EE estimates using previously developed algorithms. Results: All accelerometer algorithms underestimated EE during recovery intervals (range; -4.31 to -6.55 kCals) and overestimated EE during work intervals (0.57 to 5.70 kcals). Over the whole HIIT session, only the Hildebrand wrist method was not significantly different from the criterion measured EE. Conclusion: Current ActiGraph EE estimations based on steady-state activities underestimate EE during recovery periods of treadmill HIIT sessions. Future studies should investigate accelerometer signals immediately after high-intensity bouts to more accurately predict EE of the subsequent recovery period. KEYWORDS: ActiGraph; Accelerometer; HIIT; Indirect calorimetry; EPOC; Energy expenditure; Non-steady state; Calories

The ecohydrological effects of climate and landscape interactions within the Budyko framework under non-steady state conditions

Catchment water yield is controlled by the partitioning of precipitation into evapotranspiration, runoff, and water storage changes. As one form of the Budyko framework, Fu's equation has been widely employed to estimate the influences of climatic factors and landscape characteristics on the precipitation partitioning, with a single parameter ω reflecting the integrated ecohydrological effects of these influencing factors. However, the ecohydrological effects under non-steady state conditions are not fully understood owing to the complex hydrological and ecological processes at finer spatial and temporal scales. In addition, the finer spatial and temporal scales limit the application of the Budyko framework, since the original framework assumes that water storage changes are negligible. In this study, combining two hydrological models (the abcd model and GR2M model) and Fu's equation based on an extended Budyko framework, we estimated the ecohydrological effects of climatic factors and landscape characteristics under non-steady state conditions for 59 small catchments (≤9805 km2) in Qinba Mountains. The outputs of the two hydrological models exist good consistency with satellite-based data, with NSE exceeding 0.5 in 93% and 97% of catchments, respectively. Factors influencing the precipitation partitioning vary with timescale and exhibit greater variability at intra-annual scales. Moreover, the hydrological effects of these time-varying factors are influenced by catchment characteristics (R2 ranging from 0.01 to 0.68), implying the precipitation partitioning is controlled by the ecohydrological interactions of climate and landscape at different timescales.