Liu Model Research Articles

Volume thermal expansivity for diatomic ionic solids at high pressures and high temperatures

Volume thermal expansivity for Lif, NaF, KF, RbF and MgO have been determined using the Chopelas–Boehler approximation for the volume dependence of the Anderson-Grüneisen parameter. Expressions have been derived analytically for the thermal expansivity, pressure-volume-temperature relationship, interatomic distances and bulk modulus by developing a modified version of the Liu model. The calculated values for various properties are discussed and compared with the available experimental data and theoretical results reported in the literature.

An improved comprehensive model for assessing the heavy metals exposure towards waterbirds: A case report from Black-necked cranes (Grus nigricollis) in Caohai Wetland, China

Heavy metal contamination poses a significant environmental threat to wildlife on global scale, making accurate assessment of exposure risk crucial for conservation efforts, particularly for vulnerable species. Existing risk assessment models have been widely used, but their construction process lacks comprehensive considerations. In this study, we constructed an optimized health risk assessment model based on the well-established "Liu's model" and "ADI model", and applied the pollution allocation factor (AF) to accurately assess the risk of heavy metal exposure to wildlife. Our model was applied to assess exposure risk of heavy metal for the black-necked crane(Grus nigricollis), a flagship species in the alpine wetland ecosystem of Caohai Wetland. Soil, plant and black-necked crane fecal samples were collected from the Caohai Wetland and surrounding areas in Guizhou, China. We revealed varying degrees of As, Cd, Cr, Ni, Pb, and Zn contamination in soil and plants from different habitats, exceeding the background or plant limit values. This indicated that the black-necked crane and other waterbirds living in Caohai Wetland are suffering with the multi-elemental heavy metal contamination, especially in the gutterway and grassland. The exposure dose of As, Cd, Cr, Ni, Cu, and Zn toward black-necked cranes differed significantly in soil and plant pathways (P < 0.05). As, Cd, Cu, and Zn were mainly derived from plants consumption, while Cr and Ni originated from soil. Considering the contribution of soil and plant pathways to heavy metal exposure in black-necked cranes, the exposure doses of each elements calculated via food intake accounted for over half of the exposure calculated via feces (AF>0.5). The risk assessment model identified Cr and Pb were the highest risk elements for black-necked cranes, with exposure risk simulated through feces exceeding those through food. These findings suggested that current Liu's model may underestimate the effects of other pathways and medium. Therefore, we proposed a more comprehensive and accurate model for evaluating the exposure risk of black-necked cranes, incorporating AF to quantify the contribution of risk sources to black-necked cranes and understand their overall health risk. This model can serve as a useful tool for the conservation and habitat quality improvement of the black-necked cranes and other waterbirds.

Saturated flow boiling heat transfer of R1233zd(E) in parallel mini-channels: Experimental study and flow-pattern-based prediction

The parallel channel is widely used in the two-phase flow boiling heat transfer due to its simple structure, but the existence of multiple flow patterns causes a complex and non-unified explanation of the heat transfer mechanisms. In this study, a saturated flow boiling experiment was designed in a parallel mini channel heat sink with R1233zd(E) as the working fluid. By controlling the vapor quality difference at the inlet and outlet to around 0.1–0.2, each single flow pattern was isolated and presented in the test section, and the corresponding variations of heat transfer coefficient (HTC) were discussed. The results showed that the flow pattern during the saturated flow boiling included bubbly flow, slug flow, wavy-annular flow and local dry-out. The transition boundaries between bubbly flow, slug flow and wavy-annular flow showed good agreement with the present criteria, while a modification was made on the transition from wavy-annular flow to local dry-out. The HTC showed a fast increase under low vapor qualities, then became stable and decreased with the increase of vapor quality. In addition, 6 correlations were selected to compare with the measured HTC classified according to the flow patterns. The comparison showed that the present correlations had different prediction accuracies on the HTC data under each flow pattern. The best prediction on the heat transfer during bubbly and slug flow was achieved by Liu and Winterton's model with the MAE of 16.4% and 12.9%, while Li and Wu's model showed the best agreement with the HTC data during wavy-annular flow with the MAE of 9.1%.

Comprehensive adsorption and spectroscopic studies on the interaction of magnetic biochar from black wattle sawdust with beta-blocker metoprolol

The rise of contaminants of emerging concern in water-resources due to human activities has driven research toward wastewater treatment, specifically adsorption. The utilization of woody biomass for biochar production in adsorption has shown promise due to its high availability. This study shows the preparation of magnetic biochars (MB) from waste black wattle sawdust, utilizing ZnCl2 and NiCl2 (proportions: 1:0.5:0.5 = MB-0.5 and 1:1:1 = MB-1) as activating and magnetic agents. Synthesized via microwave-assisted-pyrolysis, MB boasts a high surface area (up to 765 m2.g−1) and functional groups, enhancing metoprolol medicine adsorption. Nonlinear kinetic and isothermal models were tested; the Avrami fractional-order kinetic model and Liu's isothermal model provided the best fits for experimental data. Thermodynamics and spectroscopic studies revealed spontaneous and exothermic adsorption processes, with physisorption magnitude and dominance of hydrogen-bond and π-π-interactions. MB can be easily extracted from an aqueous medium using magnetic fields, while adsorption capacity could be regenerated through green solvent elution.

Isotropic and Anisotropic Complex Refractive Index of PEDOT:PSS.

In this work, the complex refractive indexes of seven PEDOT:PSS samples, three with isotropic behavior and four with optical anisotropy, were determined. For the anisotropic samples, the ordinary and extraordinary components of the refractive index were described. The effect of the film thickness, measurement technique and preparation method on the extinction coefficient (k) and refractive index (n) of each sample was also discussed. Important differences (up to 20% in the average n) were found among the samples investigated. In most anisotropic films, the mean value of the extraordinary component was between 7 and 10% higher than that of the ordinary. In the three isotropic films, the average k rose when the film thickness increased. Moreover, the different sets of refractive index data were fitted to three different models: the original Forouhi-Bloomer model, the Liu (2007) model and the revised version of the Forouhi-Bloomer model (2019). In general, Liu's model gave better results, with small errors in n and k (<7.81 and 4.68%, respectively, in all the cases). However, this model had seven fitting parameters, which led to significantly longer computation time than the other two models. The influence of the differences in the measurement of the complex refractive index on the simulation of the optical properties of PEDOT:PSS multilayers was discussed. The results showed that n must be known precisely to accurately calculate the light absorption in a multilayer, without ignoring the isotropic or anisotropic behavior of the material or the influence of the layer thickness on its optical properties. This study aids in the development of simulation and optimization tools that allow understanding the optical properties of PEDOT:PSS films for their potential applications in organic optoelectronic devices, such as organic solar cells.

Optimal solar panel tilt angle calculation and simulation in Indonesia: A Liu and Jordan sky isotropic model-based approach

The efficient utilization of solar energy is crucial for meeting the growing energy demands while reducing greenhouse gas emissions and dependence on fossil fuels. Solar panel tilt angle optimization plays a vital role in maximizing the energy output of photovoltaic (PV) systems. Determining the optimal tilt angle is essential as it directly affects the amount of sunlight captured by the solar panels. In the context of Indonesia, a country rich in solar resources and a rapidly expanding renewable energy sector, understanding the optimal tilt angle for solar panels is of paramount importance. This paper studies the optimal solar panel tilt angle calculation using Liu and Jordan Sky isotropic model-based approach. The numerical simulations were carried out for several main city locations of Indonesia. The objectives of the work are to address the suitable and optimal tilt angle of solar panels by proposing an approach based on the Liu and Jordan Sky Isotropic Model. The calculation result shows that the boundary for the tilted angle empirically satisfies all the mathematical domain of the inverse trigonometric functions. While, the optimal tilted angles will be differed for any location.

Synthesis of novel mesoporous selenium-doped biochar with high-performance sodium diclofenac and reactive orange 16 dye removals

In this study, for the first time, a selenium-doped mesoporous biochar was prepared and efficiently employed for sodium diclofenac and reactive orange 16 dye adsorption. The characterization results indicated that selenium doping had a remarkable impact on Biochar-Se morphological and physicochemical structures. The efficacy of developed biochar samples on reactive orange 16 (RO-16) and diclofenac (DCF) removals was fully investigated. For both molecules (DCF and RO-16), Liu's equilibrium model offered the best fitness with maximum adsorption capacity values of 355 mg g−1 for DCF and 538 mg g−1 for RO-16 for Biochar-Se. Multiple mechanisms including pore filling, π-π interaction, and hydrogen bonding between the Biochar-Se and DCF/RO-16 molecules were involved in the adsorption process. Se-nanoparticles formed metal–oxygen bonds, which boosted the adsorption of DCF and RO-16 molecules. The current work offered a feasible approach for the development of Se-doped biochar adsorbent that is incredibly effective in treating wastewater.

Comprehensive analysis of thermodynamic models for CO2 absorption into a blended N,N‐diethylethanolamine‐1,6‐hexamethyl diamine (DEEA‐HMDA) amine

AbstractIn this work, CO2 equilibrium solubility of 1M N,N‐diethylethanolamine (DEEA):2M 1,6‐hexamethyl diamine (HMDA), 1.5M DEEA:1.5M HMDA and 2M DEEA:1M HMDA was studied with a temperature range of 298–333 K and CO2 partial pressure range of 8–100 kPa. Seven thermodynamic models including Empirical model, Kent and Eisenberg (KE) model, Hu–Chakma model, Austgen model, Helei Liu model, Liu et al. model, and Li–Shen model were developed by correlating reaction equilibrium constants with observed equilibrium solubility of CO2 in mixed amine solvents. The evaluation of those models was conducted in terms of the average absolute relative deviation (AARD). The results indicated that Liu et al. model considering T, [Amine], Ptotal and [CO2(aq)] can better represent this complex system with an AARD of 8.06%. Meanwhile, comprehensive comparison and analysis were also performed to identify the contribution of parameters to develop models, which could provide a guideline for the development of accurate thermodynamic models for representation of thermodynamic behaviors.

Adsorptive behavior of the rare earth elements Ce and La on a soybean pod derived activated carbon: Application in synthetic solutions, real leachate and mechanistic insights by statistical physics modeling

In this study, we aimed to produce a sustainable and efficient powdered activated carbon (SP-AC) and evaluate its adsorptive abilities to uptake and recover rare earth elements (REEs) from synthetic solutions containing lanthanum (La(III)) and cerium (Ce(III)), and real leachate, from phosphogypsum, containing several REEs. The adsorbent material was subjected to several characterization techniques to understand its physicochemical and adsorptive properties. The characterization results indicated that the activated carbon prepared in this work possesses a specific surface area, pore volume, and average pore diameter of 614 m2g−1, 0.121 cm3g−1, and 3.65 nm, respectively. Interestingly, the adsorbent material exhibited a highly negatively charged surface which was extremely beneficial for La(III) and Ce(III), which are positively charged and therefore were easily attracted to each other. The kinetic data were well fitted by pseudo-second-order, while the Liu model agreeably fitted equilibrium data. The maximum adsorption capacities for Ce(III) and La(III) were 107.7 and 127.2 mg g−1 at 298 K, respectively. The thermodynamic data indicated that the adsorption systems between SP-AC and both REEs were favorable, spontaneous, and exothermic. The adsorption mechanisms between SP-AC and the two REEs were proposed based on the experimental results, adsorbent characteristics, and statistical physics approach. Pore filling and ion exchange were the main mechanisms, although surface complexation was also involved. Finally, the SP-AC was employed to recover many REEs from real phosphogypsum leachate, demonstrating that SP-AC can selectively recover REEs in the real process.

#5147 PREDICTING NON-DIABETIC KIDNEY DISEASE IN PATIENTS WITH TYPE 2 DIABETES MELLITUS: EXTERNAL VALIDATION OF FOUR PREDICTIVE MODELS

Abstract Background and Aims Several prediction models have been published for estimating the probability of non-diabetic kidney disease in kidney biopsies performed in patients with diabetes mellitus. External validation and comparison of these models is essential prior to their clinical application. The aim of this study was to validate and compare the predictive capacity of four previously described clinical models as a tool to predict non-diabetic kidney disease (NDKD) in diabetic patients. Method We retrospectively reviewed kidney biopsies performed in patients with type 2 diabetes mellitus between January 1999 and December 2022 in our centre. The probability of presence of NDKD was calculated by using the clinical and laboratory parameters at the time of the decision to perform a biopsy, according to 4 models; Surinrat's model, Liu's model, Li's model and Garcia-Martin's model (see Table 1). Overall model fit was assessed, calibration curves were plotted and discrimination for each model was assessed by using the receiver operating characteristic (ROC) curve in line with the transparent reporting of a multivariable prediction model for individual prognosis or diagnosis (TRIPOD) guidelines. Results The study included 280 patients, 68.9% were males and the mean age was 65.4 ± 11.9 years. 172 patients (61.4%) had a diagnosis of non-diabetic kidney disease. On calculating the risk of NDKD, Surinrat's, Li's and Garcia-Martin's models predicted 33.6%, 64.8% and 53.4% of NDKD when using the “probable NDKD” threshold, and 60.7%, 81% and 90.7% respectively when including the “grey zones”. Fleiss’ Kappa test showed a fair agreement between the four models when using the “probable NDKD” threshold (k = 0.23, 95% CI 0.13-0.33, p&amp;lt;0.001) and when including the “grey zones” (k = 0.39, 95% CI 0.29-0.49, p&amp;lt;0.001). On using the “probable NDKD” threshold, the overall accuracy for Surinrat's, Liu's, Li's and Garcia-Martin's models was 50.7%, 62.7%, 63.6% and 65.3% respectively, while on including the “grey zones” the accuracy slightly increased in the first to models to 54.3% and 66.4% respectively while decreasing in Garcia-Martin's model to 64.2%. Area under the ROC curve (AUC) was higher in Garcia-Martin's model (AUC 0.66, 95% CI 0.58-0.74, p&amp;lt;0.001) compared to Lin's model (AUC 0.59, 95% CI 0.50-0.67, p = 0.044), while Surinrat's and Liu's models did not discriminate (AUC 0.55, 95% CI 0.47-0.64, p = 0.214 and AUC 0.58, 95% CI 0.49-0.63, p = 0.084). Conclusion There is a fair agreement between the four models for predicting non-diabetic kidney disease in type 2 diabetic patients. Of the models studied, Garcia-Martin's model most accurately predicted non-diabetic kidney disease in type 2 diabetes patients, although discrimination remained poor. These models may not be suitable for guiding clinicians on indicating a kidney biopsy in diabetic patients in our population.

Optical soliton solutions, bifurcation, and stability analysis of the Chen-Lee-Liu model

The Chen-Lee -Liu model has many applications in assorted fields, particularly in the study of nonlinear dynamics, chaos theory, circuit design, signal processing, secure communications, encryption and decryption of chaotic signals, as well as cryptography. The modified extended auxiliary equation mapping method has been applied to the Chen-Lee-Liu model in this article and explores new wave profiles, such as singular periodic solutions, periodic solutions, and kink-type soliton solutions. The complex wave conversion is considered to make a simple differential equation. Three- and two-dimensional images are plotted using Mathematica and MATLAB, and their dispersion and nonlinearity effects are discussed. We also discuss the bifurcation analysis of the studied model. The stability of the equilibrium points is studied, and the phase portrait of the system is presented graphically. The obtained wave profiles might play an important role in telecommunication systems, fiber optics, and nonlinear optics.

A new material model for concrete subjected to high rate of loading

This study presents a modified HJC model for simulating the constitutive behaviour of concrete under large strains, high strain rate and high pressure. The original HJC model has been modified by introducing the shear cracking, pore crushing, tensile cracking, and hydrostatic expansion damage models to the yield surface for reproducing the crushing, spalling (crater formed at the front surface), scabbing (crater formed at the rear surface), and radial cracking in the concrete target. The Lode-Angle model has been introduced to describe the yield surface to account for the substantial difference in the shear strength between the tensile and compressive meridians. The strain rate effect has been considered to suitably model the dynamic compressive and tensile strengths. Single element simulations have been performed to substantiate the effect of modifications introduced in the constitutive model. The results of the single element simulation obtained by using the proposed model (MHJC_K&I) have been compared with the results of the two latest modified (MHJC_Kong [1] and MHJC_Liu [2]) models available in the literature. The MHJC_K&I model has described more realistic strength softening under uniaxial compression when compared with the experiment results. Further, the MHJC_K&I model has described accurately the magnitude of tensile strength under uniaxial tension in comparison to the other two models. Under hydrostatic tension, the MHJC_K&I model described the exponential strength softening and the MHJC_Kong model described the linear softening while the MHJC_Liu model had limitation in describing the softening behaviour. The ballistic experiments have also been performed on 100 and 60 mm thick plain concrete targets against 0.4 kg steel projectile at incidence velocities in the range 103–220 m/s. The damage induced in the concrete targets as well as the residual projectile velocities have been obtained. The MHJC_K&I model has been found to effectively reproduce the damage with respect to the size and depth of the crater as well as the radial cracking at the front and rear surfaces of the plain concrete target. The MHJC_Kong and MHJC_Liu models underestimated the size and depth of the crater and described limitations in reproducing the radial cracking. The residual velocities obtained by using the proposed model (MHJC_K&I) have been found to have a good agreement with the actual results.

Integration of carbon microcapsules with beef omasum like shells by interconnected Macropores for removal of phenol from aqueous solution

A bulk carbon adsorbent with a bionic structure was synthesized based on wrinkled silica microspheres colloidal crystal templates (WSMs-CCTs). As a result, the carbon microcapsules with the internal structure of beef omasum are closely integrated by interconnected macropores to form the bulk carbon adsorbent (ICM-BO). ICM-BO was further applied as a phenol adsorbent to achieve efficient phenol removal. Compared with the reported adsorbents, ICM-BO with excellent adsorption capacity and reusability are attributed to the hierarchical nanoscale needle-like structure of the inner walls, interconnected macropores, and the robust monolith nature. The isothermal adsorption process can be well described through the Liu model with a maximum proposed absorption value of 504. 8 mg g−1 at 318 K. In addition, the morphology of ICM-BO is maintained and the regeneration efficiency (RE) is relatively stable after 10 cycles, indicating that ICM-BO has excellent reusability. Notably, in the simulated industrial effluent experiment, the removal rate of phenolic compounds by ICM-BO reach 93.5%, indicating that the ICM-BO is hardly affected by other components and has excellent adsorption capacity, which is expected to be an ideal choice for the adsorption of phenols.

Chemically activated carbon preparation from natural rubber biosludge for the study of characterization, kinetics and isotherms, thermodynamics, reusability during Cr(VI) and methylene blue adsorption.

Alkaline leachate, dust generation, and foul smell during the stacking process of natural rubber biosludge (NRBS) can pollute surrounding water, soil, and air. In this study, natural rubber chemically activated carbon (NRCAC) has been synthesized for the first time from NRBS by pyrolysis using ZnCl2 at 700 °C for adsorptive removal of Cr(VI) and methylene blue (MB) from aqueous solutions. Both NRBS and NRCAC were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS), Brunauer-Emmett-Teller (BET), and thermogravimetric analyzer (TGA). FTIR and SEM-EDS suggested significant functional and morphological transformations in NRCAC. Experimental investigations of different process parameters, such as pH, concentration, contact time, salt concentration, etc., were conducted to study their influences on adsorption. Adsorption and desorption kinetics followed a pseudo-second-order model, while adsorption equilibrium followed Liu isotherm. Maximum uptake calculated from the Liu model was 81.28 and 211.90 mg/g for Cr(VI) and MB, respectively. Thermodynamic analysis established spontaneous and endothermic adsorption. Up to five adsorption/desorption cycles were conducted using eluents such as 1 M NaOH and water for Cr(VI) and MB, respectively. Electrostatic attraction and ion-exchange favored Cr(VI)/MB adsorption, while hydrogen bonding and π-π stacking were significant in MB uptake. Overall findings suggest that NRBS (a renewable agro-industrial, abundant, and freely available) could be employed to synthesize biochar for adsorptive removal of wastewater containing Cr(VI)/MB.

Pricing formulas of binary options in uncertain financial markets

&lt;abstract&gt;&lt;p&gt;Binary options have a payoff that is either a fixed value or nothing at all. In this paper, the generalized pricing formulas of binary options, including European binary call options, European binary put options, American binary call options and American binary put options, are investigated in uncertain financial markets. By applying the Liu's stock model to describe the stock price, the explicit pricing formulas of binary options are derived successfully. Besides, the corresponding numerical examples for the above four kinds of binary options are discussed in this paper.&lt;/p&gt;&lt;/abstract&gt;

The Impact of China's AIIB on the World Bank

AbstractThe World Bank, under the stewardship of the United States, stands out as the global leader among international development organizations. Does China's establishment of the Asian Infrastructure Investment Bank (AIIB) undermine this status? Examining this question, we focus on the borrowing practices of a special set of countries: the founding members of the AIIB. These founders openly defied the public preference of the United States, arguably to create a potential rival to the World Bank. Using a new causal inference method, Pang, Liu, and Xu's Dynamic Multilevel Latent Factor Model—as well as several well-known estimation models as robustness checks—we document at least a temporary decrease in the number of World Bank infrastructure projects that the developing AIIB founders have entered into. This study presents the first systematic evidence that China's AIIB could unsettle the political influence the United States has enjoyed over developing countries through its leadership of the World Bank. An important set of countries may be parting ways with the World Bank and looking to a Chinese institution for leadership in the world of development.

BIFURCATION, PHASE PORTRAIT, CHAOTIC PATTERN AND TRAVELING WAVE SOLUTION OF THE FRACTIONAL PERTURBED CHEN–LEE–LIU MODEL WITH BETA TIME-SPACE DERIVATIVE IN FIBER OPTICS

In this paper, the fractional perturbed Chen–Lee–Liu model with beta time-space derivative is under consideration. First, the traveling wave transformation is applied to transform the fractional perturbed Chen–Lee–Liu model into two-dimensional planar dynamic systems. Second, the bifurcation of the dynamics system of the fractional perturbed Chen–Lee–Liu model with beta time-space derivative is discussed by using the theory of the plane dynamics systems. Finally, the traveling wave solutions of the fractional perturbed Chen–Lee–Liu model are obtained via the analysis method of planar dynamical system.

Inhibitory Effect of Copper on the Growth Rate of Serratia marcescens strain DRY6 on SDS

The anionic surfactant known as sodium dodecyl sulfate (SDS) or sodium lauryl sulfate (SLS) is found in a wide variety of products designed for cleaning and personal hygiene. Because of the combination of its hydrocarbon tail and its polar "headgroup," the molecule possesses the amphiphilic qualities that make it suitable for use as a detergent. Due to this it is a major pollutant in aquatic bodies. One of the most researched types of cleanup is biodegradation by microorganisms, particularly bacteria. Copper has a profound effect in inhibiting the degradation of SDS by the bacteria Serratia marcescens strain DRY6. Under different copper concentrations, the SDS-degrading bacteria grew in a sigmoidal manner with lag times of 7 to 10 hours. Overall growth was decreased when the concentration of copper was raised, with 1.0 g/L virtually completely stopping bacterial growth. Rates of expansion at various copper concentrations were calculated using a modified Gompertz model. Following the modification of the Gompertz model, the growth rates were modeled using the modified Han-Levenspiel, Wang, Liu, modified Andrews, and the Amor models. Only three of the five models (Wang, modified Han-Levenspiel, and the Liu models) were able to match the curve; the modified Andrews and Amor models did not. As for model fit, the Wang and modified Han-Levenspiel models perform admirably, but the Liu model performs poorly. The Wang model performed best statistically, with the lowest RMSE and AICc values, the greatest adjusted correlation coefficient (adR2), and AF and BF values closest to unity. The Wang model yielded estimates of 0.216 (95% confidence interval: 0.193 to 0.239), 1.05 (95% confidence interval: 0.938 to 1.167), and 0.389 (95% confidence interval: 0.148 to 0.636) for the critical heavy metal ion concentration (g/l), maximum growth rate (g/l h), and empirical constant.

Spatially varying earthquake ground motion: artificial generation and effects on earth-fill dam behavior

ABSTRACT The observed amplitude and phase differences of seismic ground motions recorded at different locations over extended areas are termed as spatially varying earthquake ground motion (SVEGM). Earthquake-resistant design and seismic risk assessment of extended structures require three-dimensional dynamic analyses for which the excitation is needed in the form of three-directional SVEGM components, where each component needs to be consistent with the coherency model. In this paper, the principal features of the performed analyses are as follows: (1) discretisation of the spatial domain at the foundation base, (2) the selection of coherency model and (3) propagation angle of the seismic waves. In the first part of the paper, three cases for the generation of three-directional SVEGM are presented. First, the two-dimensional spatial domain, representing the foundation base of the extended structure, is discretised. Second, for case 1, the three-directional SVEGM is generated using the Liu and Hong coherency model at the cells of the grid. In this case, the loss of coherency is considered independent of the direction of the wave propagation (case general). Then, for the case 2, the two different propagation angles of 30 and 60 degrees of seismic waves and the Liu and Hong coherency model are considered. Finally, using the anisotropic coherency model of Hao et al. and the propagation angle 45 degree, the three-directional SVEGM is generated, in case 3. Results show that each component of the generated SVEGM records is affected by propagation angle and directional dependency of the coherency model. The second part of the paper is devoted to two-dimensional analyses of Marun earthfill dam and three-dimensional analyses of earthfill dams with different length-to-height ratios subjected to uniform input motion and artificially generated SVEGM.

Efficient adsorption of Congo red by MIL-53(Fe)/chitosan composite hydrogel spheres

MIL-53(Fe)/chitosan composite hydrogel spheres were formed by chitosan (CS) coating MIL-53(Fe). The structural and physicochemical properties of the material were characterized by SEM, FTIR, XRD, TGA, BET, and Zeta potential. The adsorption properties of the adsorbents were systematically analyzed for different conditions, such as pH, contact time, adsorbent dosage, initial concentration, and temperature. The experimental data were fitted using adsorption isotherms, adsorption kinetics, and adsorption thermodynamics models. The results show that the pseudo-first-order model and Liu model are fitted to the adsorption kinetics and adsorption isotherm respectively. The adsorption capacity of CR reached the maximum value of 590.8 mg g−1 at 298 K. The adsorption efficiency of the composite material for CR was high, and when 100 mg L−1 CR solution was used, 99.97% of CR could be removed by reaching adsorption equilibrium. After three times of adsorption, the recovery was still close to 85%. The adsorption mechanism is mainly the synergistic effect of pore filling, ionic interactions, and hydrogen bonding.