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In this study, Lactarius deliciosus biomass was used as a biosorbent for the biosorption of three tetracycline antibiotics, chlortetracycline (CTC), doxycycline (DC), and tetracycline (TC), from aqueous solution. The biomass was characterized by Fourier Transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The effect of biosorbent amount (0.01–0.1g), pH (3.0–8.0), initial antibiotic concentration (30–300 mg/L for CTC and DC, and 5–50 mg/L for TC), contact time (2–120 min), and temperature (7 °C, 16 °C, 25 °C) were investigated. The maximum biosorption amount of CTC, DC, and TC was 216.4 ± 4.2 mg/g (pH 4.0), 121.2 ± 6.2 mg/g (pH 3.0), and 23.2 ± 2.1 mg/g (pH 7.0) at 25 °C, respectively. The biosorption amount of tetracyclines decreased with increasing temperature demonstrating that the biosorption processes were exothermic. The biosorptions of tetracyclines were favorable with negative ΔG° values for all temperatures. CTC and DC biosorption processes were well fitted to the pseudo-second-order kinetic and Freundlich isotherm models. TC biosorption data obeyed the pseudo-first-order kinetic model. Tap and drinking water samples spiked with tetracyclines were used as real samples for biosorption. The results showed that L. deliciosus biomass could be effectively used as a biosorbent for tetracycline antibiotics with high adsorption capacities. [ABSTRACT FROM AUTHOR]

The present study investigated crystal violet removal by modifying the chestnut shell with a chemical activation method. For this purpose, H2SO4 and NaOH pretreatments were applied to the chestnut shell and the pretreatment method that gave the best performance under the same conditions was determined. The best adsorption efficiency was achieved with the NaOH pretreatment (99.06%) and the crystal violet adsorption reached equilibrium within 60 min. After selecting the best chemical activation method, the modified chestnut shell was characterized before and after adsorption (FTIR and SEM). Furthermore, the effects of parameters such as pH, initial crystal violet concentration, adsorbent dosage, temperature, and contact time were observed. Moreover, isotherm, kinetics and thermodynamics of the adsorption process were researched in detail. The best results were obtained with the Langmuir isotherm model (R2=0.99) and the pseudo-second-order kinetic model (R2=0.99). Thermodynamic parameters showed that the adsorption process is spontaneous, endothermic and feasible. [ABSTRACT FROM AUTHOR]

The core–shell nanobombs integrating azo bonds (N N) and tetrasulfide bonds (S S S S) have been constructed and exhibit photothermal-thermodynamic effects, therapeutic H 2 S production, and biodegradation under the sensitive ignition by both near-infrared laser and tumor microenvironments, achieving a high efficacy against colorectal tumors. [Display omitted] • Rational design of nanobombs integrating azo and tetrasulfide bonds. • High and stable photothermal conversion due to the passivation of organosilica shell. • Photothermal-ignited nanobombs with the release of alkyl radicals. • Glutathione-ignited simultaneous H 2 S production and biodegradation due to tetrasulfide breaking. Reactive chemical bonds are associated with the generation of therapeutic radicals and gases under internal-external stimuli, which are highly attractive for cancer treatments. However, designing multifunctional nanostructures that incorporate multiple chemical bonds remains a significant challenge. Herein, novel core–shell nanobombs integrating azo (N N) and tetrasulfide bonds (S S S S) have been constructed with sensitive ignition by both near-infrared (NIR) laser and tumor microenvironments (TME) for treating colorectal tumors. The nanobombs (GNR/AIPH@MON@PVP, GAMP) were prepared by the in-situ growth of tetrasulfide-contained mesoporous organosilica nanoshell (MON) on gold nanorods (GNR) as the photothermal initiator, the load of azo compound (AIPH) as the radical producer and polymer modification. Upon NIR irradiation, the GNR core exhibits stable and high photothermal effects because of the passivation of the MON shell, leading to the thermal ablation of cancer cells. Simultaneously, the local hyperthermia ignites AIPH to release alkyl radicals to cause extensive oxidative stress without oxygen dependence. Moreover, the MON shell can be gradually decomposed in a reduced environment and release therapeutic H 2 S gas because of the cleavage of S S S S bonds by the glutathione (GSH) overexpressed in TME, causing mitochondrial injury. Owing to multifunctional functions, the GAMP significantly inhibits the growth rate of tumors upon NIR irradiation and achieves the highest efficacy among treatments. Therefore, this study presents activatable nanoagents containing multiple chemical bonds and provides insights into developing comprehensive antitumor strategies. [ABSTRACT FROM AUTHOR]

Commercial strong anion exchange resins provided by Purolite, namely MTA4801PF, and MTA4601PFSO4, were utilized for extracting uranium from sulfate leach liquor. The study focused on investigating the kinetics, isotherms, and thermodynamics of the sorption process. Both resins demonstrated similar kinetics and isotherm performance, with sorption capacities of approximately 66 and 71 mg g−1 respectively. The sorption process was proven to be endothermic, feasible, and spontaneous, and U(VI) desorption of around 95% was achieved using 0.5 M sulfuric acid. Commercial resins showed excellent sorption performance when applied to sulfate leach liquor of Egyptian ores despite the complexity of the solution. [ABSTRACT FROM AUTHOR]

In the present study, the efficacy of low-cost biosorbent obtained from walnut shells for the removal of AFB1 was examined. The characterization of the biosorbent was investigated using SEM, EDS, FTIR, XRD, and pHpzc. Maximum removal (90.5 %) was achieved using 100 mg/mL of biosorbent, pH 7.0 at 45 °C for 45 min with 100 ng/mL of AFB1. The biosorbent's adsorption capacity was found to be 178.9 mg/g as calculated using the Langmuir isotherm and assumption of monolayer AFB1 adsorption with homogenously dispersed adsorption positions on the biosorbent exterior. The kinetic data indicated the fast AFB1 uptake on biosorbent and followed the pseudo-second-order model. The thermodynamic factors revealed that the adsorption process is viable, spontaneous and endothermic. Furthermore, slight decrease in AFB1 adsorption was observed after repeating the adsorption–desorption process for 5 times. In conclusion, the obtained biosorbent is an economically, eco-friendly and promising material for the removal of AFB1. [ABSTRACT FROM AUTHOR]

A significant environmental concern globally is the pollution of water bodies as a result of heavy metals. To date, various attempts have been made to effectively remove heavy metals, such as those that use synthetic and biogenic materials to abate and control water pollution. The biological removal of pollutants from water is an efficient and environmentally friendly technique. In this study, we evaluated the biosorption characteristics of Zn2+ ions from aqueous solution by spent composed of raw Agaricus biosporium (RAB) and A. biosporium (SCAB). We added different biosorption doses, metal ions, and initial concentrations of pollutants to explore the adsorption of Zn2+ by RAB and SCAB. We applied pseudo-first- and second-order models to investigate the biosorption kinetics. According to our results, the rate of Zn2+ removal from the aqueous solution using raw biomass was significantly lower than that using sodium citrate-treated biomass of SCAB. When the Zn2+ concentration increased from 10 mg L−1 to 200 mg L−1, the rate of removal of RAB decreased from 73.9% to 38.4%, and that of Zn2+ by SCAB decreased from 99.9% to 75.9%. As we increased the biosorbent dose, the rate of Zn2+ removal by SCAB increased. Interestingly, Zn2 biosorption was inhibited by heavy co ions (Cu2+ and Pb2+) and light metals (e.g., Na+, Mg2+, K+, and Ca2+). When treating wastewater polluted with Zn2+, Pb2+, and Cu2+, SCAB showed good potential. The results of this study provide a scientific basis for an environmentally sound approach to controlling water pollution. [ABSTRACT FROM AUTHOR]

The present study used a free radical copolymerization approach to synthesize hydrogel of new poly sodium alginate (acrylic acid-co-acrylamide) grafted ZnO/CNT hydrogel nanocomposite. SA-g-P(Ac-co-AM)/ZnO-CNT hydrogel nanocomposite was characterized via X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and Field emission scanning electron microscope (FE-SEM). In the adsorption experiments, Clonazepam (CLZ) drug was used. In this study absorption process was carried out in shaker water batch for the drug and an equilibrium system to investigate the adsorption of drug onto SA-gP(Ac-co-AM)/ZnO-CNT hydrogel nanocomposite. The parameter influenced the adsorption capacities, like equilibrium time, initial of drug concentrations, pH solution temperature of solution and adsorbent dosage. The maximum adsorption capacities and removal percentage of CLZ were 95.14 mg g-1 (85.56%). The adsorption thermodynamics for drug were in accordance with isotherm Freundlich model. It is shown that adsorption of the drug is spontaneous and endothermic presses. [ABSTRACT FROM AUTHOR]

This paper presents several sufficient frameworks for multi-cluster flocking of the thermodynamic Cucker-Smale model with a unit-speed constraint (in short, TCSUS) under a singular kernel. By providing precise estimates and deriving the dissipative structure of TCSUS, it was proved that under specific well-prepared conditions for particle positions and fully separated initial velocities, multi-cluster flocking occurs in the TCSUS system under a strong singular kernel. Furthermore, the velocities and temperatures converge to the average final data for each cluster group. [ABSTRACT FROM AUTHOR]

Algerian Eucalyptus Leaves (AEL), a natural biodegradable adsorbent abundantly available, was used for the removal of methylene blue (MB) dye. The AEL properties for the removal of MB were investigated under different conditions by varying the AEL amount, MB concentration, pH of the solution and the reaction temperature. Scanning electron microscopy (SEM) and infrared spectroscopy (FTIR) techniques have been used to characterize AEL biosorbent. Experimental results showed that the adsorption of MB dye at the concentration of 50 mg L−1 reached to 91 % at pH 10 with a stirring speed of 200 rpm and after 180 min of reaction time. The experimental data were analyzed using the linear forms of different kinetic models (pseudo-first order kinetic model, pseudo-second order kinetic model, and intra-particle diffusion models). The results demonstrated that the adsorption kinetics of MB was consistent with the pseudo-second order model with R2 value of 0.9969. The isotherm models Langmuir, Freundlich, Dubinin, Elovich, Brunaut Emmet Teller and Temkin models were also investigated to describe the adsorption equilibrium. The results show that the AEL adsorption is in accordance with Temkin isotherm. The thermodynamic study revealed that the adsorption is spontaneous and exothermic. Therefore, as a cheap green adsorbent with high MB adsorption performance, AEL is expected to become one of the best candidate materials for future industrial wastewater treatment. [ABSTRACT FROM AUTHOR]

In this research, the adsorption of nickel (Ni), copper (Cu), cadmium (Cd), and zinc (Zn) from real sulfuric leaching solution with weakly acidic resins has been studied using response surface methodology (RSM). The adsorption process on two weakly acidic resins has been investigated as a function of pH, time, temperature, and resin dosage. The experimental results indicate that the amino phosphoric acid resin removed Ni, Cu, Cd, and Zn from an acidic solution very efficiently. Based on the central composite design (CCD) on the RSM, the statistical criteria of correlation coefficient (R2) values of Ni, Cu, Cd, and Zn are 0.9418, 0.9753, 0.9657, and 0.9189, respectively. The adsorption process followed the pseudo-second-order kinetic model and the thermodynamic calculations indicated the chemical interaction between the resin surface and the metal ions. Enthalpy values greater than zero indicate that the adsorption reaction of the metals is endothermic. The optimal adsorption process was carried out at time of 20 min, temperature of 30 0C, pH of 5, and resin dosage of 4 g/L. In these conditions, the adsorption capacity of nickel, copper, cadmium, and zinc were obtained 13.408, 7.087, 4.357, and 15.040 mg/g, respectively. [ABSTRACT FROM AUTHOR]

Nitrogen doped lutetium hydride has drawn global attention in the pursuit of room-temperature superconductivity near ambient pressure and temperature. However, variable synthesis techniques and uncertainty surrounding nitrogen concentration have contributed to extensive debate within the scientific community about this material and its properties. We used a solid-state approach to synthesize nitrogen doped lutetium hydride at high pressure and temperature (HPT) and analyzed the residual starting materials to determine its nitrogen content. High temperature oxide melt solution calorimetry determined the formation enthalpy of LuH1.96N0.02 (LHN) from LuH2 and LuN to be -28.4 ± 11.4 kJ/mol. Magnetic measurements indicated diamagnetism which increased with nitrogen content. Ambient pressure conductivity measurements observed metallic behavior from 5 to 350 K, and the constant and parabolic magnetoresistance changed with increasing temperature. High pressure conductivity measurements revealed that LHN does not exhibit superconductivity up to 26.6 GPa. We compressed LHN in a diamond anvil cell to 13.7 GPa and measured the Raman signal at each step, with no evidence of any phase transition. Despite the absence of superconductivity, a color change from blue to purple to red was observed with increasing pressure. Thus, our findings confirm the thermodynamic stability of LHN, do not support superconductivity, and provide insights into the origins of its diamagnetism. [ABSTRACT FROM AUTHOR]

This research investigates the effects of pack cementation parameters on the thermodynamics, growth kinetics, and microstructure of the simple and silicon‐modified aluminide coatings on the IN718 superalloy. The growth kinetic modelling of the aluminide coating, activated by NH4Cl, is established as h=174252.02T12WAl12WNH4Cl12t12exp-8306.5T ${h={{174252.02}\over{{T}^{{{1}\over{2}}}}}{W}_{Al}^{{{1}\over{2}}}{W}_{NH4Cl}^{{{1}\over{2}}}{t}^{{{1}\over{2}}}exp\left({{-8306.5}\over{T}}\right)}$. further optimizing the kinetics modelling that includes both CaCl2 activator or the mixture of CaCl2 and NH4Cl. The results showed that NH4Cl as an activator generated a higher equilibrium partial pressure of halides, which enhanced the deposition efficiency of active Al atoms and facilitated the significant precipitation of Cr‐rich carbides. Additionally, part of the CaCl2 substitute NH4Cl could maintain a high coating growth rate and reduce the hazards. Adding Si element preferentially combines with Cr formed the Cr9.1Si0.9 phase along grain boundaries, which blocked the inner‐diffusion channels of Al atoms and reduced the thickness of the silicon‐modified aluminide coating compared to simple aluminide coating. These researches revealed the relationship among the thermodynamics, growth kinetics, and microstructure of simple and silicon‐modified aluminide coatings. The thickness and microstructure of coatings can be effectively regulated by adjusting the powder composition, content, and process parameters to achieve precise control. [ABSTRACT FROM AUTHOR]

Burning fossil fuels releases toxic gases into the environment and has negative effects on it. In this study, Persian gum@Graphene oxide (Pg@GO) was synthesized and used as a novel adsorbent for CO2 capture. The characterization of materials was determined through XRD, FTIR, FE-SEM, and TGA analysis. The operating parameters including temperature, Pressure, and adsorbent weight were studied and optimized by response surface methodology via Box–Behnken design (RSM-BBD). The highest amount of CO2 adsorption capacity was 4.80 mmol/g, achieved at 300 K and 7.8 bar and 0.4 g of adsorbent weight. To identify the behavior and performance of the Pg@GO, various isotherm and kinetic models were used to fit with the highest correlation coefficient (R2) amounts of 0.955 and 0.986, respectively. The results proved that the adsorption of CO2 molecules on the adsorbent surface is heterogeneous. Based on thermodynamic results, as the value of ΔG° is − 8.169 at 300 K, the CO2 adsorption process is exothermic, and spontaneous. [ABSTRACT FROM AUTHOR]

In the search for new and novel materials for various thermo‐physical applications, we have reported the magnetic, electronic, mechanical, thermal, and thermoelectric transport properties of two full Heusler alloys (HAs), Ru2MnV and Ru2MnNb. In order to obtain a stable structure, volume optimization was carried out in the Fm‐3m (225) and F43‐m (216) space groups. The Fm‐3m space group was found to be a stable phase for both alloys. Electronic results show the metallic nature of these alloys. Ferromagnetic moments of 4.06 and 4.18 μB were obtained for Ru2MnV and Ru2MnNb, respectively. Mechanical results show a brittle nature for Ru2MnV and a ductile nature for Ru2MnNb with a high melting temperature for Ru2MnV. Thermoelectric properties such as figure of merit along with Seebeck coefficient, electrical conductivity, power factor, and thermal conductivity have also been calculated. Furthermore, the thermodynamic results of the studied materials have also been evaluated to understand the nature of various thermodynamic parameters with respect to temperature and pressure. [ABSTRACT FROM AUTHOR]

Geopolymer is one of the materials used as an environmentally friendly adsorbent and is produced from wastes such as fly ash at temperatures below 100 °C. Therefore, this study aims to investigate the adsorption process of Cu2+ and Zn2+ on the geopolymer structure by determining the isotherms, kinetics, and adsorption thermodynamics. The synthesis of geopolymer was conducted by varied Na2O/SiO2 ratios and aging time. The adsorption of Cu2+ and Zn2+ on geopolymer followed the Langmuir isotherm with the highest adsorption capacity achieved using R0.3T5 with qm 94.33 mg/g and 87.72 mg/g, respectively. Furthermore, the kinetic studies of the adsorption showed the adsorption process followed pseudo-second-order. The estimated thermodynamic parameters presented a positive value of enthalpy (ΔH°) and a negative value of Gibbs energy change (ΔG°), approving that the adsorption process on Cu2+ and Zn2+ occurs endothermically and spontaneously. More importantly, we found that the adsorption of Cu2+ and Zn2+ was influenced by the Na2O/SiO2 ratio and the pore volume of the geopolymer, which could be the basis for the further design of a more effective adsorbent. [ABSTRACT FROM AUTHOR]

A reversed-phase high-performance liquid chromatographic (HPLC) method was developed for the simultaneous determination of the potential impurities of dexketoprofen, including the distomer R-ketoprofen. After screening the separation capability of four polysaccharide columns (Lux Amylose-1, Lux Amylose-2, Lux Cellulose-1 and Lux Cellulose-2) in polar organic and in reversed-phase modes, appropriate enantioseparation was observed only on the Lux Amylose-2 column in an acidified acetonitrile/water mixture. A detailed investigation of the mobile phase composition and temperature for enantio- and chemoselectivity showed many unexpected observations. It was observed that both the resolution and the enantiomer elution order can be fine-tuned by varying the temperature and mobile phase composition. Moreover, hysteresis of the retention times and enantioselectivity was also observed in reversed-phase mode using methanol/water mixtures on amylose-type columns. This could indicate that the three-dimensional structure of the amylose column can change by transitioning from a polar organic to a reversed-phase mode, which affects the enantioseparation process. Temperature-dependent enantiomer elution order and rare enthalpic/entropic controlled enantioseparation in the operative temperature range were also observed in reversed-phase mode. To find the best methodological conditions for the determination of dexketoprofen impurities, a full factorial optimization design was performed. Using the optimized parameters (Lux Amylose-2 column with water/acetonitrile/acetic acid 50/50/0.1 (v/v/v) at a 1 mL/min flow rate at 20 °C), baseline separations were achieved between all compounds within 15 min. Our newly developed HPLC method was validated according to the current guidelines, and its application was tested on commercially available pharmaceutical formulations. According to the authors' knowledge, this is the first study to report hysteretic behavior on polysaccharide columns in reversed-phase mode. [ABSTRACT FROM AUTHOR]

This study represents an initial effort to produce NiTiFe shape memory alloys via the self-propagating high-temperature synthesis (SHS) process. The synthesis successfully yielded Ni45Ti50Fe5 and Ni40Ti50Fe10 alloys from elemental Ni, Ti, and Fe powders at three distinct preheating temperatures (240, 330, 420 °C). To support empirical findings, thermodynamic analysis using Factsage Thermodynamic Software was employed to correlate reaction propagation behavior with chemical composition. The calculation showed that the addition of 5 at.% Fe to the B2 phase did not hinder reaction self-propagation. This conclusion was supported with the ∆Hf/Cp ratio and transient liquid ratio, computed using the sub-lattice model, which closely resembled that of NiTi. Whereas 10 at.% Fe that synthesized at preheating temperature of 240 °C exhibits struggle, thus an increase in triggering time causes an effect on crystallite size and a decrease in porosity. Empirical results confirmed these findings, albeit influenced by ignition times. An increase in the liquid ratio due to the adiabatic temperature rise can also result in a reduction of NiTi content when the Fe ratio is increased, consequently diminishing the driving force for the reaction. In the sample containing – 5% Fe, the main phase is B2, and the R martensitic phase is also present. Ms is determined to be – 38.7 °C. SEM analyses revealed the presence of Ti2Ni and Ti2Ni3 phases in the upper and lower regions, while the distribution in the middle section is more homogeneous. No martensitic transformation was observed in 10% Fe. Additionally, nanocrystalline regions were detected within the samples by transmission electron microscopy, contributing to a nuanced understanding of their structural properties. [ABSTRACT FROM AUTHOR]

The ventilation design of mines is based on fluid dynamics. Air is the main fluid in mining ventilation. This fluid is analyzed by two models: incompressibility and compressibility. The air-fluid in the compressibility model is examined in two models of dry and wet air along with thermal analysis. This paper argues that a number of presented parameters in the common thermodynamic analysis of mine ventilation should be modified. Accordingly, issues of the Earth's true gravity acceleration, potential energy difference, the specific heat capacity of air at constant pressure and volume, enthalpy difference of air, the average volumetric mass of dry air, and the amount of output moisture are rechecked. Therefore, a new method is presented in this paper for correcting thermodynamic equations in mine ventilation design. The name of this method is the Complete Model of Wet Air Analysis (CMWAA method). The results of this paper show that the CMWAA method can accurately perform thermodynamic analysis of air-fluid in mine ventilation without requiring a specified evaporation rate in mine networks, with minimal iteration of calculations. [ABSTRACT FROM AUTHOR]

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Wakes produced by underwater vehicles, particularly submarines, in density-stratified fluids play a pivotal role across military, academic, and engineering domains. In comparison to homogeneous fluid environments, wakes in stratified flows exhibit distinctive phenomena, including upstream blocking, pancake eddies, internal waves, and variations in hydrodynamic performance. These phenomena are crucial for optimizing the operation of underwater vehicles. This review critically assesses the hydrodynamic and thermodynamic aspects of these wakes through an integration of theoretical, experimental, and numerical approaches. The hydrodynamic wake evolution, comprising near-wake, non-equilibrium, and quasi-two-dimensional regimes, is scrutinized. The underlying physics, encompassing energy transformation, vertical motion suppression, and momentum dissipation, are analyzed in detail. Special emphasis is placed on numerical methods, encompassing diverse approaches and turbulence models and highlighting their differences in fidelity and computational cost. Numerical simulations not only provide insights into the intricate interplay among various factors but also emerge as a crucial focal point for future research directions. In the realm of thermodynamic wakes, we delve into the thermal wake induced by the discharge of high-temperature cooling water and the cold wake resulting from the stirring of seawater. The generation, evolution, and ascent to the free surface of these wakes are explored. Additionally, this review identifies and analyzes current research shortcomings in each aspect. By systematically addressing existing knowledge gaps, our study contributes novel insights that propel academic progress and bear significant implications for submarine engineering. This work not only enhances our understanding of the intricate dynamics involved but also provides a foundation for future research endeavors in this critical field. [ABSTRACT FROM AUTHOR]

In this study, the use of natural waste containing the outer shell and seed shells of pumpkin (WSSP) in synthetic Reactive Blue 3R (RB) and Reactive Red P4BN (RR) dye removal processes was investigated. The chemical characterization of WSSP was presented by Fourier transform infrared spectroscopy (FTIR) analysis. Scanning electron microscopy (SEM) images showed the morphologies of the samples. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) curves were obtained to investigate the thermal behavior of the WSSP. Batch adsorption studies were carried out between pH 1–8, and the highest removals were obtained for RB and RR dyes as 66% at pH 3 and 92% at pH 1, respectively. The equilibrium was reached in 180 min for RB and 300 min for RR dye removal processes. The decreased particle size of the WSSP encouraged the adsorption rate. Adsorption kinetics of both processes fit pseudo-second-order kinetics. The equilibrium studies of the dye removal processes were best clarified by the Langmuir isotherm model. Enthalpy (ΔH0) and entropy (ΔS0) values of the RB dye adsorption process were 41.49 kJ mol−1 and 139.65 J mol−1K−1, respectively. For the RR dye removal process, ΔH0 value was obtained as −38.94 kJ mol−1 and ΔS0 value as −118.49 J mol−1K−1. Negative Gibb's free energy (ΔG0) values were determined for both dyes. In desorption studies, the highest desorption percentage was determined for both dyes with pH 12 distilled water. It has been determined that WSSP provides effective dye removal as an alternative and a low-cost adsorbent. [ABSTRACT FROM AUTHOR]

In this study, a MgCuAl-layered double hydroxide (MCA-LDH)-based montmorillonite cationic clay (MMT) composite was synthesized via a co-precipitation method and then characterized using various analytical techniques, including BET surface area, TEM, XRD, FT-IR, and SEM/EDS analysis, to confirm the successful loading of LDH onto MMT. The material was subsequently used as a novel adsorbent for Pb2+ ion removal from aqueous solution in batch mode experiments. The effects of important variables on Pb2+ adsorption were investigated, and the values of these variables were optimized using the central composite design (CCD) of the response surface methodology (RSM). The results showed that the favorable conditions for the adsorption of Pb2+ onto the MCA-LDH@MMt composite were pH 5, an initial Pb2+ concentration of 85 mg/l, and an adsorbent dose of 0.225 g/100 ml. Under these conditions, the maximum adsorption efficiency was 89.1%. Using the RSM methodology, a quadratic polynomial equation was obtained that expresses the relationship between the adsorption efficiency and the effective parameters. The results show that pH and temperature had a greater effect on the adsorption efficiency. The pseudo-second-order model kinetically well fitted the adsorption process, while external mass transfer and intra-particle diffusion controlled the adsorption mechanics. The Langmuir isotherm model fitted the isotherm to the adsorption process, yielding a capacity of 132.83 mg/g. The thermodynamic study showed that the spontaneous adsorption of Pb2+ onto MCA-LDH@MMt composites is exothermic in nature. Moreover, there was a mere 30% reduction in the removal efficiency after five consecutive regeneration cycles. In conclusion, this work demonstrated that the MCA-LDH@MMt composite could be a promising adsorbent for the treatment of aqueous solutions contaminated with heavy metals.

Abstract In this work, eight Mn‐RE (RE = Ce, Pr, Sm, Tb, Er, Tm, Lu, and Y) binary systems were reassessed thermodynamically by the CALPHAD method based on the reported optimizations and experimental information. Self‐consistent thermodynamic parameters to describe Gibbs energies of various phases in eight Mn‐RE binary systems were obtained. The calculated phase equilibria and thermodynamic properties of eight Mn‐RE binary systems are in good accordance with the experimental results. Furthermore, phase equilibria and thermodynamic properties of 13 Mn‐RE (RE = La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Lu, and Y) binary systems were discussed systematically in combination with the present calculations and the reported optimizations. A trend was found for the variation of phase equilibria and thermodynamic properties of the Mn‐RE binary systems. In general, as the RE atomic number increases, the enthalpies of mixing of liquid alloys as well as the enthalpies of formation of the intermetallic compounds become increasingly negative, and the formation temperatures of the intermetallic compounds become higher. The results provide a complete set of self‐consistent thermodynamic parameters for the Mn‐RE binary systems, and a thermodynamic database of 13 Mn‐RE binary systems was finally achieved.

Objective: To optimize the enzyme-assisted extraction process of polysaccharides from artificially-cultivated Cordyceps cicadae was conducted in this study. Four different parameters were considered to evaluate the yield of polysaccharides including liquid to solid ratio, enzyme dosage, enzymatic temperature and extraction time. Methods: A four-factor-three-level experimental design was employed to establish a mathematical model by Box-Behnken method, and the scavenging capacity of polysaccharides against three radicals was examined. Afterward, Fick's second law was used to build the kinetic model for the extraction of polysaccharide from artificially-cultivated Cordyceps cicadae. The parameters including rate constants, relative extraction rate, and activation energy were employed to analyze the kinetic and thermodynamic features. Results: Based on the response surface analysis, the optimal extraction process was presented to be as following: Liquid to solid ratio 1:30 g/mL, enzyme dosage 1.6%, enzymatic digestion temperature 67 ℃ and extraction time 90 min. The polysaccharide yield under the above condition was 7.91%, which was close to the predicted value. Moreover, the results of antioxidant capacities indicated that the obtained crude polysaccharides under optimal conditions showed strong DPPH radical scavenging and hydroxyl radical scavenging with IC50 values for 0.60 and 0.54 mg/mL, respectively, and its ORAC value was 45.62 Trolox μmol/g, suggesting potent antioxidant activity in vitro. Conclusion：The study of enzyme-assisted extraction of artificially-cultivated Cordyceps cicadae flower polysaccharides provide theoretical support for the production of polysaccharide fractions from this kind of commercialized Cordyceps cicadae resources.

A synthetic superabsorbent polymer hydrogel nanocomposite was prepared by the free radical graft co-polymerization method. This study included the preparation of two surfaces: first sodium alginate-g-(acrylic acid-co-sodium; 4-ethenylbenzenesulfonate), SA-g-poly (Ac-co-EBS) hydrogel, and second surface hydrogel after zinc oxide loading SA-g-poly (Ac-co-EBS). Hydrogel nanocomposite was prepared from different monomers for the removal of pollutants. The physical characterizations of nanocomposite have been studied using several techniques like UV-vis, FTIR, FE-SEM, TEM, EDX, and XRD. The data from the adsorption study show that E% increases with increasing contact time, with the best agitation time of 1 h, after which the adsorption becomes constant. The increase in adsorbent amount 0.01–0.1 g, the percentage removal of tetracycline (TC) and phenol (PH) increased from 60.639–97.085 and 487.71–94.05%, respectively, and Qe decreased 606.39–97.08 to 487.1831–94.456 mg/g on hydrogel. The ∆H value is endothermic. All processes of adsorption are considered spontaneous, from a negative value of ∆G to a positive value of ∆S. The release of the TC drug was studied in conditions similar to those in the human body in terms of acidity and temperature. The cumulative release of TC drug in 3 h was 50.65%, 42.33%, pH = 7.5 and pH 1.2, respectively.

High Co–Ni secondary hardening steels are valuable in the field of aviation materials. With the increasing demand of lightweight, further enhancing its strength has received widespread attention. In this study, instead of using only M2C carbides as the reinforcements in the traditional high Co–Ni secondary hardening steels, nano-size NiAl phases were introduced to provide additional strength. To obtain the collaborative precipitation of these two reinforcements, systematically thermodynamic calculation, including the driving force, coarsening rate, etc., was made to quantitatively tailor the composition and the two-step aging parameters. The calculation results showed that adding 1 % Al into the standard composition of M54 is a plan with high potential and a second aging process at 450 °C should be added to promote NiAl precipitation. Based on the experimental validation, the target microstructure formed as the design. With the dual-phase strengthening of NiAl particles and M2C carbides, the yield and tensile strength are greater than 2.3 and 2.7 GPa, respectively, which increases the strength of M54 steel by >30 %, retaining sufficient elongation and relatively low cost. This new designed alloy increased the strength–ductility balance of high Co–Ni secondary hardening steels and aviation maraging steels from ∼12.5 to 13.5 GPa%.

The growing demand for energy, coupled with volatile oil prices and the environmental damage caused by the harmful gases produced when it is used, has prompted countries to explore alternative energy sources. The transportation sector, an important end-user of petroleum, must adapt to the changing energy landscape and opt for new technologies to remain competitive. The study conducted a thorough thermodynamic analysis to assess the economic and environmental impact of using biodiesel (BD) made from cold-pressed linseed crude oil, commercial diesel fuel (DF), and ethanol in a compression-ignition (CI) engine. The study conducted a detailed thermodynamic analysis of performance and emission data recorded from a single-cylinder diesel engine. The analysis included energy, exergy, sustainability, exergoeconomic, exergoenvironmental, and exergoenviroeconomic parameters. The results pointed out that the fuel energy increases with the load, with B20E5 fuel reaching 6.887 kW at 25% load and 18.908 kW at 75% load. BD and blended fuels were found to have a higher fuel energy compared to DF. At 50% load, DF and B20 fuels have fuel energies of 10.765 kW and 10.888 kW, respectively. The analysis clearly demonstrates that commercial DF outperforms both DF-BD binary fuel blends and DF-BD-ethanol blends in terms of thermal and exergy efficiency values. Furthermore, DF exhibits lower entropy generation and exergy destruction than other binary and ternary blends. At maximum load, the exergy efficiencies of DF, B20, and B20E10 fuels were 28.5%, 25.8%, and 24.7%, respectively. The exergy losses were determined to be 10.495 kW, 12.317 kW, and 13.134 kW, respectively, under the same conditions. Binary and ternary fuel blends have a higher cost of power from the engine shaft due to the expensive market prices of ethanol and linseed oil-based BD compared to DF. However, B20 and B20E10 fuels have a lower environmental cost than DF, with B20 and B20E10 fuels estimated to be 2.8% and 5.3% lower than DF, respectively, at full load. These findings demonstrate the clear advantages of using B20 and B20E10 fuels over DF, both in terms of cost and environmental impact. Additionally, the infusion of ethanol into ternary blends reduces the environmental damage. This study provides a unique perspective on sustainable energy research and serves as a valuable reference for future studies.

The rise in population growth and subsequently,the spread of various diseases have led to increased production of medicines, including antibiotics. Discharging wastewater and dispersing pollutants such as drug waste in the water cycle is a very important issue that has received considerable attention in recent years. In this study, the thermodynamics of Amoxicillin and Cefixime adsorption by chitosan-polyacrylamide coated by ZIF-8 has been investigated. SEM analysis indicated that ZIF-8 is well placed in the structure of the adsorbent and no separation phases were seen. The results obtained from the temperature data in the conditions of 15 mg of adsorbent, pH 4 and adsorbent concentration of 50 ppm showed that the removal percentage decreases with increasing temperature, so it can be found that the adsorption process was exothermic. Thermodynamic parameters such as Gibbs free energy, enthalpy and entropy were also calculated. As the temperature rose, Gibbs free energy also increased, indicating that at higher temperatures, the rate of spontaneous progress of adsorption has decreased. The negative values of enthalpy and entropy in both adsorbates confirms that the reaction is exothermic and spontaneous, respectively.

AbstractIn this investigation, we employed chemical oxidative copolymerization techniques to produce cross-linked polyaniline/chitosan-graphene oxide-oxidized single-wall carbon nanotubes (Cross PANI/Chito-GO-OXS NCs) as a network to increase the surface area, as well as the active centers to enhance the efficiency of the adsorption of anionic and cationic dyes. This novel material was utilized as an adsorbent for decontaminating water by eliminating acid red dye (AR1) and brilliant green dye (BG). Several analytical techniques were employed to assess the composition and structure of the synthesized adsorbent, including scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), X-ray powder diffraction (XRD), infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and Raman spectroscopy. To assess the efficacy of Cross PANI/Chito-GO-OXS NCs in dye removal, batch experiments were carried out under diverse conditions, such as varying pH, adsorbent quantity, agitation duration, ionic strength, and temperature. The results indicated that the optimum conditions for AR1 removal were achieved at pH 2, using 5 mg of Cross PANI/Chito-GO-OXS NCs at a concentration of 20 mg/L for 120 min. Conversely, for BG removal, the most favorable outcomes were observed at pH 6, with the use of 5 mg of Cross PANI/Chito-GO-OXS NCs at a concentration of 5 mg/L for 120 min. Under these operating conditions, the maximum removal efficiency for actual wastewater was determined to be 96.73% for AR1 dye and 95.55% for BG dye. Additionally, we analyzed the adsorption isotherm data utilizing various models. The adsorption kinetics were elucidated through a pseudo-second-order model, supported by regression data, which yielded R2 values of 0.9839 for AR1 and 0.9928 for BG, respectively, describing the adsorption of both dyes onto Cross PANI/Chito-GO-OXS NCs. Furthermore, the thermodynamic analysis revealed that the removal of AR1 dye is an endothermic process, while BG dye removal is exothermic, and both removal of AR1 and BG dyes are spontaneous and chemisorption processes.

The esterification of 1-methoxy-2-propanol (PM) and acetic acid (AA) is an important reaction for the production of 1-methoxy-2-propyl acetate (PMA). Herein, we used the macroporous ion-exchange resin Amberlyst-35 as a catalyst to explore the effects of reaction conditions on the reaction rate and equilibrium yield of PMA. Under the optimized conditions of a reaction temperature of 353 K, using the initial reactant PM/AA with a molar ratio of 1:3, and a catalyst loading of 10 wt%, the PMA equilibrium yield reached 78%, which is the highest equilibrium yield so far. The reaction equilibrium constants and activity coefficients were estimated to obtain reaction thermodynamic properties, indicating the exothermicity of the reaction. Furthermore, pseudo-homogeneous (PH), Eley–Rideal (ER), and Langmuir–Hinshelwood–Hougen–Watson (LHHW) kinetic models were fitted based on experimental reaction kinetic data. The results demonstrate that the LHHW model is the most consistent with experimental data, indicating a surface reaction-controlled process and exhibiting an apparent activation energy of 62.0 ± 0.2 kJ/mol. This work represents a valuable example of calculating reaction thermodynamics and kinetics, which are particularly essential for promising industrial reactor designs.

In order to meet the hydrogen refueling demand of fuel cell vehicles and reduce the cost of HRS operation process, it is necessary to study the hydrogen refueling process of cascade hydrogen storage system of hydrogen refueling station. In this paper, a thermodynamic model of the hydrogen refueling process for fuel cell vehicles is established, and the effect of the variation of these thermodynamic parameters on the specific energy consumption and utilization rate of the hydrogen refueling process is investigated in terms of the pressure ratio and capacity of the hydrogen storage tank, which is the core of the hydrogen refueling station, consisting of multiple hydrogen storage tanks. The results show that the specific energy consumption and hydrogen utilization of the hydrogen refueling station decreases as the ratio of the nominal pressure of the medium-pressure stage to the nominal pressure of the high-pressure stage increases over the course of the pressure ratio change. In addition, the capacity variation is only slightly changed as a result of the pressure ratio variation. Therefore, the lowest ratio of specific energy consumption can be found by fixing the utilization rate and by changing the pressure ratio. For example, in this paper, if the total mass of hydrogen in the station is 600 kg and the hydrogen utilization rate is required to be not less than 12 %, the optimal pressures for each level are 50.2 MPa, 65 MPa and 86.7 MPa. • A thermodynamic model of the hydrogen filling process for fuel cell vehicles is established. • The pressure ratio and capacity of cascade hydrogen storage systems were analyzed. • Specific energy consumption and hydrogen utilization are used as evaluation indicators. • The optimal pressures for each level are 50.2 MPa, 65 MPa and 86.7 MPa. [ABSTRACT FROM AUTHOR]

The performance of sago bark for Cd(II) ions removal in the aqueous solution has been investigated using the batch method. The sago bark was facile-treated using HNO3 0.01 M and its ability on Cd(II) removal was evaluated under specific parameters such as pH, contact time, agitation speed, temperature, initial concentration, and adsorbent mass. The adsorption capacity of sago bark was found to be 2.473 mg/g. The Langmuir isotherm model corresponding to the monolayer adsorption process described the adsorption data well. The kinetic and thermodynamic evaluation confirmed that the Cd(II) ion sorption followed a pseudo-second-order model and endothermic. The adsorption capacity decreased after three times adsorption-desorption cycles. This result showed that the treated sago bark could be a good candidate as an adsorbent for Cd(II) removal. [ABSTRACT FROM AUTHOR]

Current models for inorganic ion transport in porous media describe the adsorption–desorption processes mostly based on empirical adsorption isotherms or simple thermodynamic mechanisms, often overlooking the adsorption kinetics. This study introduces a novel unified reactive solute transport model framework that incorporates well-established surface complexation models to describe the adsorption–desorption of ions in the transport process and takes into full consideration the non-equilibrium adsorption, enabling the use of the same set of thermodynamic-kinetic parameters to accurately describe ion transport under different chemical conditions. To evaluate the constructed model, Cr(VI), P(V), and As(V) column transport experiments were carried out using goethite-coated sand as the porous medium. Kinetic constants derived from single-ion transport experiments accurately predicted the cotransport behaviors of Cr(VI), P(V), and As(V) under various flow chemistry conditions, especially the overshooting phenomena of Cr(VI) under P(V) and As(V) competition. The model framework can be easily incorporated into solute transport models with various surface complexation reactions to predict the fate and transport of ions under complexed chemical conditions without extensive parameterization, and thus is a useful complement to the current reactive transport model. [ABSTRACT FROM AUTHOR]

Ametoctradin fungicide's ecotoxicological and lithospheric sorption properties have been thoroughly assessed through a variety of experimental techniques that mimic natural environmental circumstances. To achieve this, the current study examined the sorption and degradation of Ametoctradin in 10 different soil samples under carefully monitored laboratory conditions. The negative values of Gibbs-free energy (ΔG), which range from − 15.78 to − 23.56 kj/mol in thermodynamic analysis with a C-type curve are extensively assessed using both linear and Freundlich models. SS5 (soil with highest organic matter) depicted the maximum adsorption (Kd = 41.15 µg/ml), while SS8 (depicting low organic matter content) showed the lowest adsorption extent (Kd = 10.38 µg/ml). GC–MS analysis and UV–visible spectrophotometry were used to evaluate the hydrolytic and photolytic processes involved in Ametoctradin degradation. According to the findings, the hydrolytic and photolytic assays had lowest half-life values of 28.7 and 55.2 days, respectively. Furthermore, the Ametoctradin degradation followed first order reaction kinetics. Soil sample SS6 showed the maximum hydrolytic degradation (57%) due to higher sand content (42%), while SS3 showed the lowest hydrolytic degradation (21%) due to higher silt and clay content. The findings indicated that Ametoctradin exhibited above average binding to the chosen soils, resulting in medium to low persistence as shown by degradation values. Overall, this study offers insightful knowledge about the behavior and fate of Ametoctradin in various soil types, which can help with the creation of practical management plans and environmental risk assessments. [ABSTRACT FROM AUTHOR]

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Classical thermodynamic methods often encounter challenges when applied to model the intricate behavior of liquid-liquid equilibria within biofuel production systems. To overcome these limitations, Artificial Neural Networks (ANNs) have emerged as a promising avenue for effectively describing such complex systems. This study developed and evaluated ANNs to predict the behavior of two key systems, glycerol+ethanol+CO 2 and glycerol+methanol+CO 2 , employing diverse configurations and parameters. A total of 516 distinct ANNs were methodically crafted and evaluated. Notably, the Cascade Feed-Forward architecture exhibited optimal performance in predicting the CO 2 +glycerol+ethanol system, while the Elman networks excelled in predicting the CO 2 +glycerol+methanol system. The optimized ANNs were subsequently benchmarked against analogous systems in the literature by applying established thermodynamic equations. Remarkably, the results of this research work underscore the superior predictive accuracy of the ANN approach, yielding significantly diminished error values. Specifically, the mean squared error (MSE) values of 0.1283 and 0.0892 were achieved for the methanol and ethanol systems, respectively. This study contributes substantively by showcasing the ability of ANNs to surpass classical methods for accurate prediction within the intricate domain of biofuel production systems. [Display omitted] • Optimal ANNs predict CO 2 + glycerol systems accurately (MSE: 0.13; 0.09). • Predict results with a relatively small number of iterations. • ANNs offer efficiency and versatility in complex system predictions. [ABSTRACT FROM AUTHOR]

The aim of this paper is to present methods for corrosion mitigation in molten salt environments. The corrosion of structural materials depends directly on the redox potential of the salt. When the redox potential of the salt is higher than the standard potentials of the elements constituting the structural materials, corrosion occurs. If the reverse is true, no corrosion is observed. Herein, a methodology for calculating the theoretical potential of a molten salt is provided and compared with experimental measurements. Three ways to mitigate corrosion by modifying the salt redox potential are proposed: (i) using a soluble/soluble redox system; (ii) using a potentiostatic method; and (iii) using an amphoteric compound such as UCl3, TiCl2, or TiCl3. Immersion tests were conducted under the above conditions to validate the methodology. [ABSTRACT FROM AUTHOR]

This study aims to environmentally synthesize and fully characterize CdO nanoparticles by utilizing an eco‐friendly process that involves Crocus sativus in its reaction with cadmium ions. The CdO nanoparticles underwent characterization, and their purity was confirmed through XRD and UV‐Vis spectroscopy. Additionally, scanning electron microscope and transmission electron microscopy revealed that the prepared cadmium oxide nanoparticles exhibited polymorphism, with diameters ranging between 42 and 67 nm. Furthermore, the Fourier transformation infrared spectroscopy showed the main bands of cadmium oxide at 1047, 542, and 1310 cm−1. Furthermore, the cadmium oxide nanoparticles were employed in a study focusing on gas storage, particularly hydrogen (H2) storage. The results of the hydrogen storage study demonstrate that the maximum H2 uptake reached 2.85 Wt.%H2 at a pressure of 69 bar at 77 K, with ∆H = 0.62607 KJ/mol H2 and ∆S = 3.35697 J/mol H2·K. Moreover, thermodynamic investigations at four different temperatures confirm that the maximum H2 uptake can be achieved within a pressure range of 69–86.2 bar. [ABSTRACT FROM AUTHOR]

The study aimed to prepare a biocomposite containing Yarrowia lipolytica yeast cells with magnetic properties. The work proposes the use of this biocomposite as a sorbent for the removal of organic pollutants like methylene blue from liquids. The sorption process was conducted in a periodic process through which different parameters were analyzed such as initial concentration (50–250 mg/dm3), time of the process (0.167–24 h), and temperature (25–40 °C). To fit the experimental data to theoretical models, the Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models were used. In addition, pseudo-first-rate, pseudo-second-rate order, Weber–Morris and Elovich kinetic models were evaluated. The highest fit was the Freundlich isotherm model (R2 = 0.9959 and ARE = 3.41%) and the pseudo-second-rate order model (R2 = 0.9989 and ARE = 1.14%). It has been shown that the process of removing methylene blue using a biocomposite is exothermic and its usefulness decreases with an increase in temperature (from 32.10 mg/g to 23.64 mg/g). To acquire information about the material characteristics, different instrumental methods were applied: FTIR, SEM-EDX, TGA, and VSM. This study provides new information on the possibility of using composites made of biochar, yeast, and magnetic particles in the process of removing dyes from an aqueous environment. The obtained biocomposite is effective in removing contaminants and is easily separated after the performed process. [ABSTRACT FROM AUTHOR]

The biomass of a yeast stain of Wickerhamomyces anomalus was evaluated as a natural biosorbent for the removal of Acid Red14 dye (AR14) in batch experiments. The outcome revealed a maximum biosorption capacity of 71.37 mg g−1. Biosorption kinetic followed both the pseudo-second-order and intra-particle-diffusion model, while thermodynamic parameters showed a spontaneous and endothermic nature of the biosorption process. The Freundlich model was the best-fitting isotherms, suggesting a monolayer biosorption via chemisorption at homogeneous sites on the yeast surface. Next, the physicochemical characterization of W. anomalus biomass before and after biosorption using scanning electron microscopy coupled with X-ray spectroscopy, and the Fourier-transforms infrared spectroscopy indicated the involvement of various functional groups (amino, carboxyl, hydroxyl, and carbonyl groups) in AR14-biosorption. Also, the zeta potential of cells at a negative charge, and the acidic value of the zero-charge point confirmed the predominance of anionic groups in the cell wall. Hence, H-binding, π-π, and n-π interactions are likely to participate in the biosorption mechanism. Additionally, the influence of batch conditions on the decolorization capacity was statically screened and optimized using Plackett–Burman and Box–Behnken design, respectively. Results show that biomass dosage is the significant factor having a positive influence on the discoloration rate, while a negative correlation was found for dye concentration and high pH values. Maximum decolorization (77%) was achieved at pH level (3–4), with dye concentrations (50–75 mg L−1) and yeast biomass 1.25 g L−1. These results suggest that W. anomalus might be exploited as an effective, inexpensive, and environmentally friendly biosorbent. [ABSTRACT FROM AUTHOR]

AbstractIn recent years, the world has suffered from the pandemic of the century, known as COVID-19. A significant effort has been exerted to develop new and more efficient treatments in order to find an effective cure. As a result, various pharmaceutical products have been tested and utilized. However, the presence of emerging contaminants such as these pharmaceuticals in aquatic environments poses a serious threat, as their actual effects on both the environment and human health remain largely unknown.Therefore, the present study aims to investigate the potential use of activated carbon derived from cocoa shells for the effective removal of hydroxychloroquine (HCQ) from aqueous solutions. Batch experiments were conducted to evaluate the capability of this type of activated carbon to eliminate this persistent pharmaceutical from aqueous systems.The cocoa shell activated carbon demonstrated a high adsorption capacity (98%) under mild operating conditions, including an adsorption time of 180 min, a pH of 7, an activated carbon dosage of 1.5 g L−1, an initial HCQ concentration of 10 mg L−1, and a stirring speed of 400 rpm at 297 K. The adsorption kinetics were best described by the pseudo-second-order model, while intraparticle diffusion was found to be a suitable description for higher concentrations.Further insight was gained by applying isotherm and thermodynamic studies. The results indicated that the adsorption isotherm followed Langmuir, Freundlich, and Temkin models. Moreover, the thermodynamic analysis revealed that the adsorption of HCQ onto the cocoa shell-activated carbon is exothermic and spontaneous. [ABSTRACT FROM AUTHOR]

Al-Cu-Mg high-strength alloys are widely used in industrial production because of their excellent mechanical performance and good machining properties. In this study, first-principles calculations based on density functional theory were carried out to investigate the influence of Mg doping on the structural stability and mechanical properties of the Al2Cu (θ) precipitated phase in Al-Cu-Mg alloys. The results show that the structural stability, electronic structure, bulk modulus, mechanical anisotropy, and thermodynamic properties of the precipitated Al2CuMgX phase change with the concentration of Mg doping (X = 2, 4, 6, and 8). The cohesive energy calculation and electronic structure analysis show that Al2CuMg6 has a high structural stability. The criterion based on elastic constants indicates that Al2CuMg2, Al2CuMg4, and Al2CuMg8 have a brittle tendency and show strong anisotropy of mechanical properties, while Al2CuMg6 shows better comprehensive mechanical properties. The thermodynamic analysis results based on the quasi-harmonic Debye model show that the Al2CuMg6 precipitated phase has good stability at high temperatures and pressure. [ABSTRACT FROM AUTHOR]

In this study, the performance of cross-linked microbeads prepared through suspension polymerization was investigated for removal of 4-hydroxybenzoic acid (4-HBA) from aqueous solution. Adsorption studies were conducted at different pHs (2.0-8.0), temperatures (282-308 K) and initial 4-HBA concentrations (1-500mg/L). The maximum 4-HBA adsorption was 49.05 ± 2.89mg/g at pH 2.0 (282 K). The adsorption data obeyed to the Langmuir isotherm model. The modified Ritchie second-order and the pseudo second-order kinetic model fitted the adsorption data. The 4-HBA adsorption capacity did not significantly change after 10 consecutive usages. Gibbs free energy changes of the adsorption were calculated as -24.372, -28.431 and -29.093 kJ/mol for 282, 298 and 308 K, respectively. The microbeads were also used for the removal of 4-HBA from spiked river water samples. The removal efficiencies of 43.2% to 68.8% and RSDs of 0.49% to 4.78% demonstrated the usability of the microbeads in application. [ABSTRACT FROM AUTHOR]