Realistic constitutive ground models are critical in the evaluation of soil‐structure interaction problems and the assessment of key design parameters in the seismic analysis of infrastructure ...systems. In the present study, the modified pseudo‐dynamic lateral earth pressures acting on retaining structure with granular backfill of depth‐varying damping ratio are evaluated adopting the lower bound limit analysis in conjunction with the finite element (FE) discretization method using second‐order cone programming (SOCP). The earthquake loading is simulated by the propagation of shear and primary waves through non‐constant inertia forces in the horizontal and vertical directions, respectively. The influence of varying damping ratio alongside the retaining wall height on the seismic active and passive lateral earth pressures is effectively taken into account by adopting well‐established formulas published in the literature. It is shown that failing to consider the damping variation with depth while performing the modified pseudo‐dynamic analysis could lead to precarious, unrealistic estimates of design parameters.
•Insight on the physical processes related to the dynamic and the residual method.•The correct effective discharge is difficult to assess experimentally using the dynamic method.•Dynamic ...overestimation < 15 % if the ratio between the estimate and the pressure drop is > 0.70.•The residual capillary pressure is not a property of the material.•Using bigger vessels and imposing higher overpressures the residual estimate is more accurate.
The dynamic threshold pressure method and the residual capillary pressure method provide an estimate of the threshold capillary pressure for CO2 storage. In the dynamic method, the threshold capillary pressure is determined by comparing the discharge measured when the CO2 starts flowing into the sample with the one measured when only water is flowing. In the residual method, a high CO2 pressure is applied on the vessel at the inlet of a water-saturated sample while water cannot flow from the vessel at its end. The threshold capillary pressure is estimated as the difference between the CO2 and the water pressures at the sample boundaries at equilibrium conditions.
Sensitive analyses showed the impact of material properties and experimental conditions on results. Both methods allow estimating the threshold capillary pressure within a few days and the estimates are influenced by the applied pressures. The dynamic method estimate is not precautionary, and it tends to the exact value as the applied CO2 overpressure decreases. The residual method estimate is influenced by the drainage conditions and the volume of the vessels: it is generally precautionary and tends to increase with the volume of the vessels and the applied pressure. Suggestions for test interpretation and planning are also provided.
Abstract
Non-methane volatile organic compounds (NMVOC) are important precursors of ozone and secondary organic aerosols in PM
2.5
(particulate matter with aerodynamic diameters smaller than 2.5
μ
...m), both of which cause severe climate, ecosystem, and human health damages. As one of the major anthropogenic sources, onroad vehicles are subject to relatively large errors and uncertainties in the estimation of NMVOC emissions due to complicated methods and parameters involved and a lack of comprehensive evaluation of influencing factors. Here, based on our previous work with necessary improvement, we estimate China’s vehicular NMVOC emissions by county and by month during 1990–2016 with a consideration of meteorological influence on the spatial-temporal dynamics of emission factors. Our estimate suggests that vehicular NMVOC emissions in China have peaked around 2008 and then declined up to 2016 with an enlarged contribution of the evaporative process to vehicular NMVOC emissions. Vehicular NMVOC emissions have been dominated by the evaporative process at present. Meteorological factors alter spatial-temporal distributions of NMVOC emissions, especially evaporative emissions, which are enhanced in South China and in summer. Emissions and ozone formation potential of the major chemical groups (i.e. Alkenes, Aromatics, and Alkanes) also increase substantially due to meteorological influences. Our analysis suggests that mitigation strategies for vehicle pollutions should be designed based on a sophisticated emission inventory accounting for the meteorological impact on emission factors to correct the potential underestimation of NMVOC emissions, especially those from the evaporative process.
Display omitted
•Solubility data of2,4-TDA, 4-TMC and 2,4-TDCinDMC and DOP solvents were determined.•The experimental solubility of 2,4-TDA, 4-TMC and 2,4-TDC was correlated by different ...thermodynamic models.•Solubility increase with the increasing of temperature.•Dissolution properties of 2,4-TDA, 4-TMC and 2,4-TDC were calculated based on the modified Van't Hoff.
The solubilities of 2,4-diaminotoluene (2,4-TDA), methyl 3-amino-4-methyl-N-phenyl carbamate (4-TMC) and dimethyl toluene-2,4-dicarbamate (2,4-TDC) in dimethyl carbonate (DMC) and di(2-ethylhexyl) phthalate (DOP) were determined by dynamic method at 298.15 ∼ 398.15 K under atmospheric pressure. The solubility data were correlated by the modified Apelblat equation, polynomial equation and simplified two-parameter equation. The modified Apelblat equation was more accurate than the others. In addition, the thermodynamic properties of the solution process, including the Gibbs energy, enthalpy and entropy were calculated by the modified Van't Hoff equation. The dissolution process of 2,4-TDC in DOP solvent is a non-spontaneous entropy reduction endothermic process. The dissolution processes of 2,4-TDA, 4-TMC and 2,4-TDC in DMC solvent and 2,4-TDA and 4-TMC in DOP solvent are all non-spontaneous entropy-increasing endothermic processes.
The Young's modulus is an essential factor for improving turbine blade design. The present study aims to obtain the flexural frequencies (f1) and corresponding dynamic Young's modulus (Ed) of ...Ni‐based single‐crystal DD6 across a temperature range of 25–1200 °C using a nondestructive dynamic testing method. The relationship between the elastic constants and various crystal orientations is derived by employing the transformation of the elastic matrix. In addition, finite element (FE) simulation is conducted to calculate the flexural frequency (f1) of the 001 crystal orientation. The findings indicate that the dynamic Young's modulus (Ed) decreases as the temperature increases within the range of 25–1200 °C. Furthermore, the Ed values for different crystal orientations follow the trend: Ed1 < Ed11 < Ed111. This suggests significant anisotropy in the material. The normalized model, matrix transformation calculation method, and finite element method demonstrate high accuracy in predicting the elastic modulus of DD6, as evidenced by the good correspondence between the fitting curves obtained using the normalization method and the test results. These results have practical applications in engineering, particularly in turbine blade design and other applications, and serve as valuable references for mechanical property testing and finite element simulations.
A nondestructive dynamic testing method is developed to obtain flexural frequencies (f1) and dynamic Young's modulus (Ed) of Ni‐based single crystal from 25 to 1200 °C. The normalized model, matrix transformation calculation method, and finite‐element method demonstrate high accuracy in predicting Ed. These results have practical applications in engineering, particularly in turbine blade design and application.
•The solubility data of DCTNB was measured in sixteen mono-solvents.•The solubility experimental data are correlated through five solubility models.•The enthalpy, entropy and Gibbs free energy of the ...DCTNB dissolution process were calculated.
The solubility of 1,3-dichloro-2,4,6-trinitrobenzene (DCTNB) in sixteen mono-solvents (methanol, ethanol, isopropanol, n-butanol, toluene, xylenes, dichloromethane, chloroform, carbon tetrachloride, 1,2-dichloroethane, acetone, ethyl acetate, acetonitrile, N-methylpyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide) was measured by a laser dynamic method over the temperature range from 298.15 K to 333.15 K under 0.1 MPa. The results show that the solubility of DCTNB increase with increasing temperature in sixteen mono-solvents. Within the experimental temperature range, the average solubility of DCTNB was recorded as the maximum data in N-methylpyrrolidone (29.55 × 10−2) and the minimum data in isopropanol (0.26 × 10−2). The modified Apelblat equation, Yaws model, van't Hoff equation, λh equation, and new correlative combined model were used to correlate the solubility of DCTNB in sixteen mono-solvents, and the modified Apelblat equation and Yaws model showed satisfactory accordance with the experimental data. Furthermore, the thermodynamic properties of DCTNB dissolution process in the investigated mono-solvents, including standard dissolution enthalpy (9.08 ∼ 47.66 kJ·mol−1), standard dissolution entropy (18.61 ∼ 101.59 J·K−1·mol−1) and standard Gibbs free energy (3.22 ∼ 16.12 kJ·mol−1) were calculated by the van't Hoff and the Gibbs equations. The results demonstrate that the dissolution behavior of DCTNB in sixteen mono-solvents is a non-spontaneous and endothermic process. The solubility data, correlation models, and thermodynamics properties presented in this study would provide essential support for the research of purification and crystallization of DCTNB.
Slope entropy (SloEn) is an effective nonlinear dynamic method to represent the complexity of time series, which has been extensively applied to various mechanical signal processing. However, it is ...only applicable to the analysis of single-channel time series at a single scale. Additionally, thresholds γandδ of SloEn can affect the division of symbols. To address these limitations, this paper firstly develops multivariate SloEn (mvSloEn) and extends it to multiscale mvSloEn (mvMSloEn), which not only accounts for the correlation of time series complexity within and across channels, but also mirrors the complexity of multi-channel time series over multiple scales. Furthermore, the sea-horse optimization-mvMSloEn (SHO-mvMSloEn) is proposed through utilizing the sea-horse optimizer (SHO) to fine-tune the thresholds for improved performance. Finally, the proposed SHO-mvMSloEn is applied to three real-world datasets and the highest classification accuracies are all over 98 %, superior to the existing multivariate multiscale dispersion entropy (mvMDE), multivariate multiscale fuzzy entropy (mvMFE), and multivariate multiscale sample entropy (mvMSE), which demonstrates that the proposed SHO-mvMSloEn always exhibits the best feature extraction capability.
•Multivariate slope entropy (mvSloEn) is first devolved.•The mvSloEn is extends it to multiscale mvSloEn (mvMSloEn).•The sea-horse optimization-mvMSloEn (SHO-mvMSloEn) is proposed.•Our method always exhibits the best feature extraction capability.
The conventional pseudo-dynamic (CPD) and modified pseudo-dynamic (MPD) methods are invoked to obtain the seismic bearing capacity of strip foundations using the limit equilibrium method, with a ...two-wedge failure mechanism. A spectral version of the conventional pseudo-dynamic method (SPD) is also invoked by considering the ground motion amplification factor, to be a function of the non-dimensional frequency
λ/B
and soil damping. Numeric analyses show that bearing capacity results obtained by the MPD and SPD methods are generally consistent. Both experience the same general reduction in bearing capacity with the increase of
λ/B
, with successive ups and downs corresponding to soil’s natural frequencies. For 5<
λ/B
<10, SPD and MPD results fluctuated between falling above and below CPD results. For
λ/B
<2.5, SPD and MPD results were consistent with attenuation of the shear wave, while for 10<
λ/B
, amplification was exhibited. Results obtained by the CPD method monotonically decrease, due to the fact that CPD fails to inherently consider site effects and damping, and instead and relies on a single factor to consider the ground motion amplification.
Farm management is related to the decisions that affect the profitability of this business. Limited resources are allocated, and after taking a certain risk, a return is expected. In order to manage ...risk effectively, it needs to be clearly identified and valued.
Determining the production structure of an agricultural holding in the current study is considered in the short term, in the case of choosing between two annual crops. Solving this problem in the future involves establishing the amount of investment funds, areas in which to invest, and the use of tangible fixed assets as efficiently as possible.
In carrying out the investment process, financial and investment decisions are made, developing this dynamic method for every possible alternative to investing capital.
The purpose of this study is to propose a method for making management decisions in agriculture, when choosing to invest financial resources in terms of choosing between two crops - wheat and sunflower.
PDF
