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Tourism is a dynamic industry due to changes in the consumer market, and its constant development impacts the host community. Although the adverse outcomes of tourism are not a new phenomenon, new dynamics make this issue of ongoing importance. Governments see the activity primarily as fostering economic development in developing countries with little concern about possible overtourism. This article aims to identify which indicators influence residents' perceptions of tourist saturation as an indication of overtourism. These perceptions are examined as a multidimensional construct, comprised of several indicators, namely environmental, cultural, behavioral, public services, benefits, and economic costs. The proposed model is assessed with a sample of 477 residents in coastal destinations of Santa Catarina, Brazil. The results show that the perception of excessive numbers of tourists is increased by environmental indicators, economic costs, and behavioral indicators. These indicators contribute to a greater perception of overtourism. In contrast, the indicators of economic benefits and public services show a negative relationship with the perception of overtourism. This research indicates that when the population realizes the economic benefits and has access to quality public services, the perception of overtourism is lower. The findings contribute to the literature on overtourism in certain destinations.

This article investigates the distributed fault-tolerant time-varying formation control problem for multiple unmanned airships (UAs) against limited communication ranges and input saturation to achieve the safe observation of a smart city. To address the strongly nonlinear functions caused by the time-varying formation flight with limited communication ranges and bias faults, intelligent adaptive learning mechanisms are proposed by incorporating fuzzy neural networks. Moreover, Nussbaum functions are introduced to handle the input saturation and loss-of-effectiveness faults. The distinct features of the proposed control scheme are that time-varying formation flight, actuator faults including bias and loss-of-effectiveness faults, limited communication ranges, and input saturation are simultaneously considered. It is proven by Lyapunov stability analysis that all UAs can achieve a safe formation flight for the smart city observation even in the presence of actuator faults. Hardware-in-the-loop experiments with open-source Pixhawk autopilots are conducted to show the effectiveness of the proposed control scheme.

This article proposes an adaptive neural-network control scheme for a rigid manipulator with input saturation, full-order state constraint, and unmodeled dynamics. An adaptive law is presented to reduce the adverse effect arising from input saturation based on a multiply operation solution, and the adaptive law is capable of converging to the specified ratio of the desired input to the saturation boundary while the closed-loop system stabilizes. The neural network is implemented to approximate the unmodeled dynamics. Moreover, the barrier Lyapunov function methodology is utilized to guarantee the assumption that the control system works to constrain the input and full-order states. It is proved that all states of the closed-loop system are uniformly ultimately bounded with the presented constraints under input saturation. Simulation results verify the stability analyses on input saturation and full-order state constraint, which are coincident with the preset boundaries.

Quantifying the amount of gas hydrate in a reservoir provides valuable insight on gas hydrates’ potential as a resource and their contribution to the global carbon cycle. We develop a new method to estimate hydrate saturation from density-sensitive X-ray computed tomography (XCT) scans of pressure cores from northern Gulf of Mexico (Green Canyon Block 955). While several studies have used XCT to quantify gas hydrate in the fractures of fine-grained sediments, our study is the one of the few to use XCT for coarse-grained (sand and silt) reservoirs. We calibrate our new method with grain density and quantitative degassing measurements from the same intervals. This paper uses the density difference between gas hydrate (0.924 g/cm3) and porewater brine (1.035 g/cm3) and assume these changes linearly affect the XCT measurements allowing for estimates of hydrate saturation. Overall, the XCT calculations agree with the hydrate saturation from quantitative degassing. For example, in core H005-3FB-3, quantitative degassing indicated a hydrate saturation of 88 ±33.5%, while the XCT calculations yielded a 90 ±4 4.8% saturation. These results are encouraging as they suggest that XCT analysis has the potential to nondestructively estimate hydrate saturation.

This article studies the fault-tolerant leader-following consensus problem for multiagent systems with input saturation. The main contribution is to present a modified low-and-high gain feedback approach to deal with multiple actuator faults, including partial loss of effectiveness, outage, and stuck simultaneously. First, without consideration of saturation, a distributed fault-tolerant control scheme is put forward by the adaptive technique, and a practical finite-time stability result is established. Second, by employing the fault-tolerant theory and introducing a novel form of parametric algebraic Riccati equation, a modified low-and-high gain feedback approach is developed for the saturated control strategy. It is proven that the practical finite-time stability can be achieved, and both the steady-state consensus error and the settling time can be well estimated. Finally, numerical simulations are provided to validate the effectiveness of the theoretical results.

This paper proposes some effective approaches to address the inherent issues of consequent-pole (CP) permanent magnet (PM) machines, such as saturation of the salient rotor core and unipolar PM leakage flux of the end region caused by asymmetric field. The effect of CP Halbach PM array with different magnetization direction and parameters that affect the saturation have been investigated for the CP PM machine with short pole pitch. By employing the CP Halbach array, the saturation issue can be solved and superior performance can be obtained without reducing the PM pole arc. In addition, unequal and multistep staggered rotors with magnetic barriers have been proposed to reduce the unipolar leakage flux in the end region. Compared with regular staggered rotors, not only better electromagnetic performance can be achieved, but also the end unipolar leakage flux can be reduced. Finally, a prototype is manufactured and the predictions have been validated by measurements.

Accurate measurement of electrical currents cannot be done when the core of current transformers (CTs) is saturated. One of the reasons that causes saturation of a CT is the activation of the auto-reclose function for the circuit breaker. When the circuit breaker is switched off, a residual flux will remain in the CT core, and when the circuit breaker is reconnected, this residual flux may cause saturation of the CT core. It is necessary to remove the residual flux in an auto-reclosing scheme. In the auto-reclosing scheme, due to the short time interval between each reclosing shot of the circuit breaker, only methods that have a high-speed operation should be used to mitigate the residual flux to prevent CT core saturation. This paper introduces a fast and complete demagnetization method based on Jiles-Atherton magnetic modeling to mitigate the residual flux in the CT core. The advantages of this method are high-speed performance, independent of the CT characteristics, high accuracy and high reliability against the secondary open circuit. To evaluate the efficacy of the proposed method, software simulations and laboratory experiments are performed on a 63kV, 300A/5A CT. The results are presented and analyzed.

Clay soils, usually in an unsaturated state, are widely used as barrier materials in solid waste landfills. When the saturation of clay soils is high, the gas phase will be in the form of entrapped...

The secure consensus problem of multiagent systems with input saturation and denial-of-service (DoS) attacks constraints is an interesting research problem. To solve this problem, the assumptions that all the agents own the same saturation level and suffer the same DoS attacks from a single adversary are usually made. This paper removes the above assumptions and investigates the secure consensus problem of multiagent systems with different saturation levels and multiple DoS attacks. The studied multiagent systems have different layers, in which different saturation levels are studied for different layers. Moreover, the DoS attacks are launched from different adversaries and will cause different effects for different agents. To achieve the desired objective, two different consensus protocols for agents in different levels are first designed using the low-gain technique. Then, the investigated dynamic system under DoS attacks is modeled by a switched system by categorizing the DoS attacks into several types. The controller is proposed by solving parametric algebraic Riccati equation (ARE). Sufficient conditions for the DoS attack duration on each channel are derived.

This paper investigates the distributed fixed-time attitude coordinated control problem for multiple spacecraft subject to actuator saturation under the directed topology. First, a distributed fixed-time observer is presented for each follower spacecraft to estimate the leader spacecraft’s states. Compared with the commonly used fixed-time observer, the settling time of the proposed fixed-time observer can be easily adjusted by some free design parameters. Next, a distributed fixed-time control scheme is derived by using the estimates of the leader spacecraft's states and the adding a power integrator technique. When considering actuator saturation, an auxiliary system is utilized to compensate the saturation. Further, a rigorous theoretical proof is provided to show that the practical fixed-time stability of the closed-loop system is ensured. Finally, simulation results illustrate the benefits and effectiveness of the developed control scheme.

This article addresses the cooperative fault-tolerant control problem for networks of stochastic nonlinear systems with actuator faults and input saturation. The fuzzy neural networks (FNNs) are employed to estimate the unknown functions and stochastic disturbance terms. To analyze the nondifferential saturation nonlinearity, a smooth nonlinear function of the control input signal is constructed to estimate the saturation function. A novel adaptive fault-tolerant control protocol is proposed by using backstepping design technique. By using the stochastic Lyapunov functional strategy, it is proved that all the followers’ outputs eventually converge to a small neighborhood of the leader’s output, and all the signals in the closed-loop systems are bounded in probability. Finally, the performance of the proposed control strategy is illustrated through simulation.

Vacuum freeze-drying is a promising technology widely used in pharmaceuticals. Preparing products with prebuilt porosity has attracted considerable attention due to its potential in shortening process duration. However, the design space for the primary drying of initially unsaturated products remains unclear. A novel index, average power, was proposed in this paper to represents the collapse risk. And a multiphase model was employed in this paper to build the design space for the products with initial voids. The simulation results show that both the drying time and average power show higher sensitivity to the temperature variation than pressure. In addition, the initial saturation has significant impacts on the design space, with small initial saturation resulting in vast design space and vice versa, which implies that small initial saturation is more beneficial for the actual production. This paper would be helpful for the development of freeze-drying.

Accurate parameters are critical to permanent magnet synchronous machine (PMSM) drive. This paper investigates accurate flux linkages, inductances and PM flux linkage estimation for PMSM with core loss compensation. With conventional model, core loss will induce the flux linkage error especially in the deep saturation region. Hence, this paper firstly proposes a novel differential modeling technique to compensate core loss, in which differential measurement is defined as the incremental value calculated from the actual measurements under two different speed conditions. With multiple differential measurements, the flux linkage error due to core loss can be compensated to improve the accuracy of flux linkage estimation. Then, the polynomial based flux linkage model is employed to derive the PM flux linkage and cross-saturation inductances. Self-inductances are estimated from the flux linkage model using least squares method. The proposed approach can accurately estimate parameters without the need of core loss data and can improve the estimation accuracy especially in deep saturation region, which is validated on a laboratory interior PMSM and compared with existing methods under various operating conditions.

Stony soils that have a considerable amount of rock fragments (RFs) are widespread around the world. However, experiments to determine the effective soil hydraulic properties (SHPs) of stony soils, i.e., the water retention curve (WRC) and hydraulic conductivity curve (HCC), are challenging. Installation of measurement devices and sensors in these soils is difficult, and the data are less reliable because of their high local heterogeneity. Therefore, effective properties of stony soils especially under unsaturated hydraulic conditions are still not well understood. An alternative approach to evaluate the SHPs of these systems with internal structural heterogeneity is numerical simulation. We used the Hydrus 2D/3D software to create virtual stony soils in 3D and simulate water flow for different volumetric fractions of RFs, f. Stony soils with different values of f from 11 % to 37 % were created by placing impermeable spheres as RFs in a sandy loam soil. Time series of local pressure heads at various depths, mean water contents, and fluxes across the upper boundary were generated in a virtual evaporation experiment. Additionally, a multistep unit-gradient simulation was applied to determine effective values of hydraulic conductivity near saturation up to pF=2. The generated data were evaluated by inverse modeling, assuming a homogeneous system, and the effective hydraulic properties were identified. The effective properties were compared with predictions from available scaling models of SHPs for different values of f. Our results showed that scaling the WRC of the background soil based on only the value of f gives acceptable results in the case of impermeable RFs. However, the reduction in conductivity could not be simply scaled by the value of f. Predictions were highly improved by applying the Novák, Maxwell, and GEM models to scale the HCC. The Maxwell model matched the numerically identified HCC best.

Stator and rotor cores of interior permanent magnet (IPM) motors are usually saturated, and the saturation distribution and saturation depth vary with the stator current. Also, their rotor structures are complex; hence the saturation cannot be accurately reflected by a saturation factor. These considerations lead to existing equivalent air-gap length models of induction motors and inset permanent magnet (PM) motors no longer suitable for IPM motors. Therefore, based on the consideration of stator and rotor saturation, this paper proposes the equivalent air-gap length model of IPM motors expressed by magnetic potentials on the stator inner surface and the rotor outer surface. The proposed equivalent air-gap length model can accurately reflect the influences of complex structure and severe saturation of IPM motors. Compared with existing models, the proposed one is no longer uniquely determined by motor structure parameters; it is also a function of stator current and rotor position. Furthermore, the obtained equivalent air-gap length model is combined with the winding function and the modified winding function to solve the inductances under different stator currents and different rotor eccentricity states. Finally, the proposed method is verified by both finite element analysis (FEA) and experiments.

This paper addresses the noncooperative attitude tracking control problem for rigid bodies whose dynamics evolves on the rotation matrix (Formula presented.). First, based on the relative attitude measurement, a saturated angular velocity input is designed by a proposed saturated nonlinear function. Thereafter, the attitude tracking control torque for rigid body's dynamics with input saturation constraint and active disturbance rejection is developed by a modified dynamic surface control approach which can avoid large torque in practice. Furthermore, by using only relative attitude measurements, two types of velocity-free attitude control laws are considered, respectively. In contrast to those control schemes that require that the desired angular velocity is available to the rigid body, the proposed scheme is able to solve the attitude control in noncooperative scenarios, where the desired angular velocity and acceleration are not accessible. Since the attitude described by rotation matrix (Formula presented.) enables the controller to use local measurements in the body-fixed frame rather than global measurements in an inertial frame, the proposed robust noncooperative control schemes with input saturation constraint are easier to implement in practice. Finally, numerical simulations and SimMechanics experiments are provided to illustrate the effectiveness of the proposed theoretical results.

This article investigates a fault-tolerant control problem for heterogeneous vehicular platoons with actuator faults and saturation. The occurrence of actuator faults may yield large control signals to avoid performance loss, which can potentially lead to saturation of the actuator that may cause further performance deterioration or even instability. To compensate for the effects of actuator faults and saturation, an adaptive fault-tolerant control method is proposed based on nonlinear vehicle dynamics and a new quadratic spacing policy. The improved quadratic spacing policy is introduced to remove the assumption of zero initial spacing errors. The nonlinear vehicle dynamics is approximated by a radial basis function neural network (RBFNN). The adaptive fault-tolerant platoon control method is developed in the context of PID-type sliding mode control technique, and proved to be capable of guaranteeing individual vehicle stability, string stability and traffic flow stability. The effectiveness of the method is verified through comparison simulation studies.

Interfacial reactions between the electric arc furnace (EAF) slag, i.e., CaO–SiO2–FeO–MgO–Al2O3–MnO system, and the magnesia refractory as a function of direct reduced iron (DRI) addition (0, 10, 20, 30 wt%) were investigated at 1550 °C under an Ar atmosphere. MgO solubility increases with increasing DRI content by decreasing basicity (i.e., CaO/SiO2 ratio), which is due to an increase in SiO2 supplied from DRI. The measured MgO content was always lower than the theoretical MgO saturation level irrespective of DRI content because the magnesiowustite (MW) intermediate layer, which formed at the slag/refractory interface, retarded the direct dissolution of the refractory by acting as a self-protective layer. The thickness of the MW intermediate layer and dissolution depth were proportional to DRI content. However, the penetrativity decreased with increasing DRI content by decreasing the fluidity of the slag. Several kinetic parameters were estimated, including the dissolution rate constant of the MW intermediate layer, the dissolution rate of the MgO refractory, and the rate constant of MW growth. Dissolution of MgO refractory is controlled by the dissolution of the MW intermediate layer. Increasing the growth rate is very important for protecting refractory after the formation of a MW intermediate layer. In addition, we provided a schematic diagram of the slag/refractory interfacial reaction phenomena that compares situations of low and high DRI content. The results of the present study show that it is necessary to control DRI content to minimize refractory degradation during the EAF process. If a large amount of DRI must be used in the EAF process, then MgO content in the slag should be at the saturation limit at first, which accelerates growth of the MW intermediate layer.

Natural gas hydrate (NGH) reservoirs consist of the types of sediments with weak cementation, low strength, high plasticity, and high creep. Based on the kinetics and thermodynamic characteristics of NGH decomposition, herein a heat-fluid-solid coupling model was established for studying the wellbore stability in an NGH-bearing formation to analyze the effects of the creep characteristics of NGH-bearing sediments during long-term drilling. The results demonstrated that the creep characteristics of sediments resulted in larger plastic yield range, thus aggravating the plastic strain accumulation around the wellbore. Furthermore, the creep characteristics of NGH-bearing sediments could enhance the effects induced by the difference in horizontal in situ stress, as a result, the plastic strain in the formation around the wellbore increased nonlinearly with increasing difference in in situ stress. The lower the pore pressure, the greater the stress concentration effects and the higher the plastic strain at the wellbore. Moreover, the lower the initial NGH saturation, the greater the initial plastic strain and yield range and the higher the equivalent creep stress. The plastic strain at the wellbore increased nonlinearly with decreasing initial saturation.

This article addresses the saturated stabilization control problem for nonholonomic vehicles with a novel c-nonholonomic trajectory approach on $\text{SE}(2)$ , with applications to automatic parking. First, by defining the c-nonholonomic configuration, a c-nonholonomic trajectory is obtained, which provides a novel approach to design stabilization controller to reach an arbitrary configuration. Second, a global discontinuous time-invariant feedback controller with input saturation is proposed, which does not involve time signal information, and its convergence is illustrated by a Lyapunov function approach. Thereafter, the motion trajectory of the proposed controller is analyzed, and the application scenario in automatic parking with the approximate desired trajectory is demonstrated. Finally, the performance of the proposed controller is validated by both numerical simulations and experiments.

The traditional Hassler-Brunner (HB) interpretation method of centrifuge capillary pressure is widely used in materials, soil, biotechnology, and especially in the petroleum industry. However, the assumptions of the traditional method cannot be simultaneously satisfied, the traditional method has been known to lead significant errors in some cases. In this paper, a new double integral method is proposed to evaluate the centrifuge capillary pressure of long tight sandstone samples. Both the changes of capillary length and interface of wetting phase and non-wetting phase fluids are considered by the new integral method, thus the average pressure and saturation derived from the proposed double integral method is more sufficient in theoretic foundation and clearer on physical meaning. By comparing with the measured capillary pressure of long tight sandstone core samples from porous plate, the capillary pressure calculated from traditional HB method is obviously smaller than the measured value, and the discrepancy increases with the decreasing core porosity. However, the average capillary pressure obtained by the proposed double integral method is remarkably consistent with the measured value. The findings of this study can help for better understanding of distribution of wetting phase fluid and average centrifuge capillary pressure in the core during centrifugal process.

The formation of uranyl phosphate precipitates is a remediation strategy to limit the mobility of uranium in contaminated soils. However, exposure to organic ligands, like the plant exudate citrate, can remobilize the uranium. The purpose of this study is to provide a more thorough comprehension of citrate-promoted dissolution of a uranyl phosphate mineral, chernikovite [(H3O)(UO2)(PO4)•3H2O], by determining the extent of uranium release from chernikovite at a wide range of citrate concentrations. We have quantified the kinetics of dissolution and proposed potential mechanisms of chernikovite dissolution to gain a better understanding of the fate of uranyl phosphate precipitates in the environment. Batch dissolution and continuously stirred tank reactor (CSTR) experiments indicate that increasing citrate concentrations from 0.1 mM to 50 mM increases the concentration of dissolved uranium. However, at citrate concentrations of 10 mM and greater, the effectiveness of the ligand to enhance the dissolution decreases. Density functional theory modeling and Raman spectroscopy indicate a strong interaction between citrate and the uranyl ions at the surface of the uranyl phosphate. The interaction between citrate and uranyl suggests the formation of an alteration layer of uranyl-citrate surface complexes, which could impede uranium release at citrate concentrations of 10 mM or higher. Together, these results indicate that the citrate-promoted dissolution of chernikovite is a fast reaction that is hindered by a combination of surface saturation and a secondary-phase precipitation reaction at higher concentrations of citrate and reaction times greater than or equal to 72 minutes based on the hydraulic residence time of CSTR experiments. These findings improve our understanding of the stability of uranyl phosphate for use in sequestration of uranium groundwater plumes at contaminated sites.

Refereed/Peer-reviewed In this article, the analysis of induction machines using five separated subdomains including the rotor slot, rotor slot opening, airgap, stator slot opening, and stator slot regions is considered. The Maxwell equations of each region are solved considering the boundary conditions. Uniform distributions of the current density in the rectangular slots of both the rotor and stator are considered to find the energy of the winding and to calculate the machine inductances using the energy equation. The calculated flux density of each subdomain is used to find the flux distribution. The calculated magnetic flux intensities are required to estimate the saturation level of the motor cores and correct the saturation-related values such as the leakage and magnetizing inductances. The machine core losses are calculated based on the Steinmetz equation at the no-load condition. The calculated inductances and resistances are used in the equivalent circuit of the squirrel-cage induction machine (SCIM) for the performance prediction. The results demonstrate the reliability of the saturation model in the prediction of the saturation influence in a wide range of magnetization levels. The accuracy of the proposed model in the prediction of the performance of the SCIM is validated using two-dimensional (2-D) and 3-D finite-element analysis results. A sensitivity analysis with 75 different geometries was conducted to show the capability of the model for the performance prediction of a wide range of induction machines.

Soil salinization is one of the major forms of land degradation processes from all over the world. The dielectric constant plays an important role in the process of soil salinity retrieval by using microwave remote sensing. The Dobson model has been widely used to simulate the dielectric constant of nonsaline soil, but the estimated result of the Dobson model did not perform well for saline soil. Moreover, the ions' concentration is related to soil salinity, and the electrical conductance is a critical factor that influences the imaginary part of the dielectric constant. Therefore, the relationship between them needs to further explore. In addition, saturation is neglected in the current dielectric model of saline soil. In this letter, the relationship between the electrical conductance and ions' concentration was analyzed based on the experimental data. The saturation as a new parameter was introduced into the Dobson model to improve the estimated accuracy of the dielectric constant of saline soil in the C-band. The comparison between the revised model, the Dobson model, the Hu Qingrong (HQR) model, and the Wu Yueru (WYR) model was presented. The results indicate that there is a significant linear relationship between the electrical conductance and ions' concentration, with R² of 0.996, a slope of 0.1456, and an intercept of 0.0252. Once the new parameter is implemented, the improved dielectric model based on the C-band reproduces the dielectric constant of saline soil satisfactorily in each soil sample. The simulated results of the improved model are consistent with the laboratory measurement results, with an RMSE of 0.97 and R² of 0.953. Compared with other commonly used three dielectric models of the saline soil, the improved dielectric model performs well in simulating the imaginary part of the dielectric constant. The improved agreements between the simulations and the measurements indicate that the revised dielectric model is appropriate for simulating the dielectric constant of saline soil. The revised dielectric model of saline soil will provide a scientific foundation for the soil salinity retrieval from the microwave remote sensing technology.

A method for the synthesis of reduced-order dynamic output-feedback controllers for periodic discrete-time LPV systems, subject to input saturations and external noises, is proposed in this paper. The controllers are designed to guarantee the robustness of the closed-loop system to exogenous noises, achieved through the minimization of a bound for the L 2 gain. The proposed method is based on a two-stage procedure, where a state-feedback gain is computed in the first stage and then applied on the second step to generate the desired controller. A third stage is then developed to synthesize an anti-windup compensation to deal with the input saturation, but since the controller is not fixed in this step, the control system dynamics can be redesigned to better aggregate the desired robustness to the external noises and input saturation, decreasing the conservativeness of the technique. The validity of the proposed method is validate through a numerical example.

The three-axis attitude tracking control of an underactuated spacecraft in the large-angle maneuver was investigated in this study. As a major contribution of this paper, a robust controller was developed to achieve the perfect attitude tracking of the underactuated spacecraft with consideration of saturation and uncertainties. Interestingly, due to non-singularity of this design, it could relax the burden of limiting the initial condition of the quaternions. The stability analysis of the developed controller could be guaranteed by Lyapunov method as shown here. Overall, the simulation results indicate that the proposed controller has robustness against saturation, external perturbations, inertia uncertainties, and internal disturbances of actuators. As result, the controller was asymptotically stable under the combination of the soft saturation and the perturbations so that attitude parameters converged to the desired path within the 230 s. In this case, the saturation level was consumed 0.08 N.m. Also, it was still asymptotic stable under the hard saturation whose level is equal to 0.01 Nm, 12.5% of the soft saturation level.

A process variability analysis is carried out to find the most influencing input parameter and corresponding output parameter variation using the L9 approach. The common factors, levels, parameters, and responses are mentioned in the following section. The mean response curve for the output parameters is also presented. Empirical relations are obtained for finding the responses in terms of the common factors. EBX936 (Non-Crimp bidirectional, Glass Reinforcement Manufactured by-Tech. Textile, USA) with 3, 6, 12 number of layer (NOL) is the material system used in the analysis. The infusion pressure is kept in the workable range of 60 to 70 kPa as normally used in the VARTM process. Very high vacuum at inlet increases the resin velocity through the preform and hence the time of infusion will reduce drastically, giving very little time for proper saturation of fibers in the preform. Therefore, to keep the velocity in the middle range of velocities during the infusion low injection pressures are selected. The viscosity of the resin is selected in the range 0.2 to 0.3 Pa.s.

Recently, remote sensing (RS) technology are becoming an increasingly important technology in estimating forest growing stem volume (GSV), and the saturation issue of spectral variables from various optical sensors severely hinders the improvement of mapping forest GSV, especially in the planted forest with high GSV. Forest canopy height is widely considered as one of the major factors to increase the saturation levels in mapping GSV. However, it is rather difficult to invert the forest canopy height without precisely external DEM for large regions. In this study, the canopy height model (CHM) was derived from ZY-3 stereo images with subtracting open-sourced external DEM and the response of saturation levels was analyzed by adding forest height in the planted coniferous forest (Larch and Chinese pine). To further describe the relationships between the forest height and saturation levels, five datasets with five estimation models (Linear, MLR, SVR, KNN, and RF) and three methods of variable selection (Stepwise, LASSO, and Pearson) were applied to estimate the forest GSV using corrected CHM and 49 alternative variables extracted from ZY-3 multispectral images. Meanwhile, a spherical model was employed to quantitatively describe the saturation levels of combined variables. The results showed that values of relative root means square error were decreased from 29.3% to 25% for Larch and from 26.5% to 22.2% for Chinese pine after adding the corrected CHM, respectively. Meanwhile, the saturation level of each combined variable set was successfully determined by the spherical model. The results illustrated that the saturation levels of GSV were significantly increased by adding corrected CHM from open-sourced external DEM. Specially, the averaged saturation levels were increased from 220 m3/ha to nearly 300 m3/ha for Chinese pine and from 150 m3/ha to 220 m3/ha for Larch, respectively. It is proved that ZY-3 stereo and multispectral images have great potential for accurate estimation of forest GSV by delaying the saturation levels using extracted CHM with open-sourced external DEM.

Hypothesis: While the lack of efficient tools yielding controllable uniform saturation ratios (S) has delayed basic experimental heterogeneous nucleation studies, common diffusive condensation particle counters (DCPCs) could fill this gap if their S-variation were minimized by increasing the proportion of sheath gas (σ) surrounding a central core of purified clusters. Analysis: We measure the activation probability P of Tetraheptylammonium Bromide cluster cations (THA-Br)n-1THA+ in Kanomax’s fast CPC while controlling S through the saturator and condenser temperatures (Ts, Tc), varying σ, and changing the size (n) of purified salt clusters via high resolution mobility selection. Findings: Experimental curves P(Ts,n) obtained in 1-butanol/air at fixed Tc (13 °C) and variable n and Ts (3 ≤ n ≤ 16; 30 ≤ Ts ≤ 40 °C) rise sharply versus both n and Ts. Their steepness increases five-fold with increasing σ to about σ = 75%, with little effect thereafter. Measurements changing S would yield size distributions of unknown aerosols at fairly high resolution. Comparing P(Ts,n) data with predictions from capillary theory suggests that basic heterogeneous nucleation measurements can be carried out, but instrument improvements are still needed.

We measured barium attachment and detachment fluxes from and to barite crystal surfaces in solutions with [Ba]/[SO4] ratios from 0.06 to 52. The doping of 137Ba in the initial experimental solutions enabled us to measure unidirectional fluxes near solubility equilibrium (Q/K ≈1.0) in batch reactors. Both attachment and detachment fluxes increase with [Ba]/[SO4] ratios. As expected, since the solutions were near solubility equilibrium ( S I ≈ 0.0 n ), the attachment and detachment fluxes were nearly equal. The experimental data can be fit accurately using the Zhang and Nancollas (1998) (ZN98) process-based AB crystal growth model, which describes crystal growth and dissolution through nucleation and propagation of kink sites. Simultaneous fitting step velocity data of Kowacz et al. (2007) significantly reduced the number of non-uniqueness solutions. The remarkable fit implies that barite recrystallization at room temperature near equilibrium and moderate supersaturation occurs via ion-by-ion addition and removal, rather than the formation of amorphous precursors or aggregation of particles. The model is best fit using different detachment frequencies for Ba and SO4, suggesting the ZN98 assumption that detachment frequencies should be the same for the constituent ions does not apply to barite. Based on experimental data and model fitting, Ba attachment and detachment fluxes at a fixed saturation state increase with [Ba]/[SO4] ratios monotonically. This has potentially significant implications for interpreting isotope and trace element cycling in natural environments.

As one of hydrofluoroolefins, trans-1,1,1,4,4,4-hexafluoro-2-butene (R1336mzz(E)) is treated as a novel working substance for organic Rankine cycles as well as heat pumps for its low GWP, non-flammability, and lower toxicity. The objectives of this study are the viscosity measurement for R1336mzz(E) in liquid, vapor, and supercritical regions by the method of tandem capillary tubes and the development of correlations for the saturated liquid and vapor viscosities. The viscosity measurements for R1336mzz(E) were conducted over the range of temperature from 314 to 394 K for the liquid, 391 to 453 K for the vapor, and 413 to 453 K for the supercritical region, respectively, at pressures from 1.0 to 4.0 MPa. The expanded uncertainties in the viscosity measurement are calculated as 2.26 % for liquid, 2.30 % for vapor, and 2.32 % for supercritical phase using k=2 and 95 % confidence level. The experimental data are correlated with the ECS model; the AAD is 5.04 % for the liquid, 22.19 % for the vapor, and 11.88 % for the supercritical phase, respectively. The saturated viscosities are also estimated by the extrapolation from the measurements to the liquid-vapor saturation conditions. For industrial design and simulation, simple correlations are developed in terms of the saturation temperature to predict the viscosities of the saturated liquid and vapor phases, respectively.

Objectives This study aimed to evaluate the optical properties of highly translucent 5 mol% yttria, partially stabilised monolithic zirconia, and 3 mol% yttria-stabilised tetragonal zirconia after their subjection to different milling methods and artificial ageing. Methods Two types of pre-shaded zirconia materials were used: inCoris TZI C and Katana STML. A total of 120 specimens were categorised according to the milling method (dry or wet-milling) and the solution used for milling (fresh distilled water or impregnated water with residues of CAD/CAM ceramic materials). The translucency and contrast ratios of all specimens were calculated after they were subjected to sintering and accelerated ageing. The material phase composition was tested before and after ageing, using X-ray diffraction analysis to evaluate T-M phase transformation. Data were statistically analysed via a three-way analysis of variance between the subject factors, the material and milling method, and the within-subject factor, ageing. The analysis of covariance model was used to analyse the changes in translucency and contrast ratio between baseline and ageing, with statistical significance set at p Results Katana STML and inCoris TZI C showed the highest translucency when dry-milled (21.9 ± 1.4, and 11.8 ± 0.7, respectively), and the lowest when milled with used impregnated water (5.4 ± 1.2 and 10.7 ± 1.3, respectively). Wet-milling using impregnated water, should be avoided owing to the saturation of alumina particles. Accelerated ageing resulted in the same pattern for both materials. Significance Dry milling of highly translucent zirconia can result in higher translucency and lower contrast ratio values.