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This study aims to investigate the adsorption characteristics of tetracycline from polluted waters using C-4- hydroxyphenylcalix[4]resorcinarene as an adsorbent. The adsorptive efficiency of C-4-hydroxyphenylcalix[4]resorcinarene is optimized by adjusting various operational parameters such as the adsorbent dosage, the pH, the contact time, the temperature, and the initial adsorbate concentration. The most efficient remediation is 96% at 10.0 mg/L tetracycline as the initial concentration, 0.05 mg/L C-4-hydroxyphenylcalix[4]resorcinarene, a contact time of 30 min, pH 5.6, and ambient temperature. The adsorption ability of C-4-hydroxyphenylcalix[4]resorcinarene toward tetracycline is also investigated in water with different characteristics, including solutions with and without the addition of background salts. The results show that C-4-hydroxyphenylcalix[4]resorcinarene can effectively remove tetracycline from aqueous solutions with an adsorption capacity of ca. 36.9 mg/g. The study also finds that the removal process followed pseudo-second order kinetics and Freundlich isotherm models. Moreover, the adsorption is spontaneous and exothermic, suggesting a thermodynamically favorable chemisorption process. In addition, the optimized method is successfully applied to remove tetracycline from various real natural water systems. [ABSTRACT FROM AUTHOR]

• Developed a Third-order model for optimization of D-FVHP. • NSGA-II is used to optimize dynamic and thermodynamic performances. • Eight structure parameters for dynamic performance are optimized simultaneously. • Nine structure parameters for thermodynamic performance are optimized simultaneously. • free stroke is improved by 78% and electromagnetic work is reduced by 87.72%. Free-piston Vuilleumier heat pump (FVHP) is a heat pump driven by thermal energy such as the combustion of natural gas. Thus, it is a more energy-efficient way for heating than boilers. In this work, one dimensional computational fluid dynamic model is developed for FVHP with dwell motion. Structural design parameters of FVHP are optimized for higher C O P t o t a l based on the coupling of developed model and NSGA-II (Non-dominated Sorting Genetic Algorithm-II) under the condition of given heating capacity. 8 structural parameters are optimized for dynamic performance. The results show that free stroke is improved by 78% and C O P t o t a l is improved by 2.61%. Then, based on the obtained optimal 8 structural parameters, 9 structural parameters for thermodynamic performance are further optimized. The results show C O P h is increased by 3.04% while the heating output power is only reduced by 3.15% [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HAP) coupled with its two modifications HAP P123 and HAP F127 were applied for indium removal from aqueous solutions. Adsorbents' abilities to remove indium ions were assessed in relation to pH, time of contact, indium concentration, temperature, and presence of co-existing ions. Adsorption was discovered to be pH-dependent for all sorbents, with maximum indium ion removal at pH 4.0. Both the Langmuir and the Freundlich isotherm models were used to explain the experimental results. For all adsorbents, the Freundlich isotherm provided a better description of the equilibrium of the sorption. The sorption capacity computed from the Langmuir model changed from 10,799 mg/g for HAP F127 to 11071 mg/g for HAP. A number of models were used to describe the adsorption's kinetics. The adsorption of indium on HAP was better described by the pseudo-second-order model, on HAP P123 by the pseudo-first-order model, and on HAP F127 by the Elovich model. Thermodynamic parameters showed that indium ions' adsorption onto HAP adsorbents was a feasible, spontaneous, and exothermic process. The effectiveness of indium removal by the examined adsorbents was unaffected by the presence of other metal ions in the solutions. ORCA quantum chemistry software was used to theoretically examine the interactions between the surfaces of adsorbents and the indium ions. High desorption efficiency showed that the applied adsorbents can be used for manifold wastewater treatment. [ABSTRACT FROM AUTHOR]

The solubility of thiamine nitrate in {(methanol, acetone, isopropanol) + water} solvents will provide essential support for crystallization design and further theoretical studies. In this study, the solubility was experimentally measured over temperatures ranging from 278.15 to 313.15 K under atmospheric pressure using a dynamic method. The solubility increased with increasing temperature at a constant solvent composition. The dissolving capacity of thiamine nitrate in the three binary solvent mixtures at constant temperature in the low ratio of water ranked as water + methanol > water + acetone > water + isopropanol generally. Interestingly, in the high ratio of water systems, especially when the molar concentration of water was greater than 0.6, the dissolving capacity ranked as water + acetone > water + methanol > water + isopropanol. Additionally, the modified Apelblat equation, λh equation, van't Hoff equation and NRTL model were used to correlate the solubility data in binary mixtures. It turned out that all the selected thermodynamic models could give satisfactory results. Furthermore, the thermodynamic properties of the dissolution process of thiamine nitrate were also calculated based on the modified van't Hoff equation. The results indicate that the dissolution process of the thiamine nitrate in the selected solvents is all endothermic. [ABSTRACT FROM AUTHOR]

The use of low-cost adsorbent such as bottom ash has been investigated as a replacement for the current expensive materials for removal dyes from aqueous solution. The adsorbent was obtained from incinerated hospital waste (Mascara, Algeria). The prepared adsorbent was characterized by X-fluorescence, XRD, scanning electron microscopy, specific surface area (BET method) and pH(PZC). The results indicated that the material consisted of silica, carbonates and sodium chloride. The surface area and PZC were 1.29 m2/g and 8.9, respectively. The solid was applied for the removal of synthetic dyes namely Disperse Yellow 3 and Reactive Brillant Blue at various contact time, pH values and solution temperatures. The optimum pH and equilibrium time were 8.3 and 60 min, respectively. The dyes were adsorbed in single and binary solution. The adsorption isotherms show that the reactive dye was better adsorbed (269.36 mg/g) than the dispersive dye (120.64 mg/g). The adsorbed amounts of the dyes onto bottom ash were not affected by the type of system. The adsorption data were fitted with the linear forms of the Langmuir, Freundlich and Dubinin–Radushkevich models. Overall, the Langmuir isotherm showed a better fitting for all adsorptions under investigation in terms of correlation coefficient. Among the kinetic models tested, the adsorption reaction follows the pseudo-second-order kinetic controlled by intra-particle diffusion. In the both systems, the free energy and enthalpy changes obtained revealed that the process was spontaneous and endothermic. The positive entropy change confirms the enhancement of disorder near interface liquid/solid. [ABSTRACT FROM AUTHOR]

This research presents the results of the immobilization of Candida Antarctica Lipase B (CALB) on MOF-199 and ZIF-8 and its use in the production of biodiesel through the transesterification reaction using African Palm Oil (APO). The results show that the highest adsorption capacity, the 26.9 mg·g−1 Lipase, was achieved using ZIF-8 at 45 °C and an initial protein concentration of 1.20 mg·mL−1. The results obtained for the adsorption equilibrium studies allow us to infer that CALB was physically adsorbed on ZIF-8 while chemically adsorbed with MOF-199. It was determined that the adsorption between Lipase and the MOFs under study better fit the Sips isotherm model. The results of the kinetic studies show that adsorption kinetics follow the Elovich model for the two synthesized biocatalysts. This research shows that under the experimental conditions in which the studies were carried out, the adsorption processes are a function of the intraparticle and film diffusion models. According to the results, the prepared biocatalysts showed a high efficiency in the transesterification reaction to produce biodiesel, with methanol as a co-solvent medium. In this work, the catalytic studies for the imidazolate, ZIF-8, presented more catalytic activity when used with CALB. This system presented 95% biodiesel conversion, while the biocatalyst formed by MOF-199 and CALB generated a catalytic conversion percentage of 90%. Although both percentages are high, it should be noted that CALB-MOF-199 presented better reusability, which is due to chemical interactions. [ABSTRACT FROM AUTHOR]

Chemical flooding is a beneficial approach to enhance oil recovery from hydrocarbon reservoirs. Surfactant flooding due to the capability of oil/water interfacial tension (IFT) reduction is a very well-known approach. However, the adsorption of surfactants on the rocks' surface makes this approach less feasible and too complex to model. This study attempts to analyze the adsorption behavior of saponin on sandstone rocks. Saponin is a natural surfactant found in more than 500 plant species. The adsorption behavior of this surfactant follows the Langmuir isotherm model with a negligible error of 0.98%. Experimental studies revealed that saponin adsorption capacity decreases when the temperature rises, but the behavior still follows the Langmuir isotherm model in elevated temperatures. Furthermore, the effect of particle size on adsorption behavior was also investigated experimentally, whereas smaller particles were found to provide higher adsorption capacities for saponin molecules. In the current research, a model based on thermodynamic equations has been constructed capable of predicting the adsorption behavior of saponin on sandstone rocks in extended conditions. Experimental data were also employed to verify the model performance. Moreover, the core plug and batch adsorption capacities were compared to each other, which showed that the core adsorption capacity is much lower than the batch condition. Comparing results achieved in this study with other natural surfactants, it is explicit that saponin induces a ten times lower critical micelles concentration (CMC) and adsorption tendency on sandstone rocks, which can make saponin a superior natural surfactant with invaluable applications in chemical EOR jobs. [ABSTRACT FROM AUTHOR]

Polydopamine-functionalized nanosilica was synthesized using an inexpensive and easily obtainable raw material, mild reaction conditions, and simple operation. Subsequently, a flexible spacer arm was introduced by using dialdehyde starch as a cross-linking agent to bind with laccase. A high loading amount (77.8 mg·g−1) and activity retention (75.5%) could be achieved under the optimum immobilization conditions. Thermodynamic parameters showed that the immobilized laccase had a lower thermal deactivation rate constant and longer half-life. The enhancement of thermodynamic parameters indicated that the immobilized laccase had better thermal stability than free laccase. The residual activity of immobilized laccase remained at about 50.0% after 30 days, which was 4.0 times that of free laccase. Immobilized laccase demonstrated excellent removal of phenolic pollutants (2,4-dichlorophenol, bisphenol A, phenol, and 4-chlorophenol) and perfect reusability with 70% removal efficiency retention for 2,4-dichlorophenol after seven cycles. These results suggested that immobilized laccase possessed great reusability, improved thermal stability, and excellent storage stability. Organic-inorganic nanomaterials have a good application prospect for laccase immobilization, and the immobilized laccase of this work may provide a practical application for the removal of phenolic pollutants. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate the potential of a new lignocellulosic biosorbent material derived from mature leaves of sour cherry (Prunus cerasus L.) for removing methylene blue and crystal violet dyes from aqueous solutions. The material was first characterized using several specific techniques (SEM, FTIR, color analysis). Then, the adsorption process mechanism was investigated through studies related to adsorption equilibrium, kinetics, and thermodynamics. A desorption study was also performed. Results showed that the Sips isotherm provided the best fit for the adsorption process of both dyes, with a maximum adsorption capacity of 168.6 (mg g−1) for methylene blue and 524.1 (mg g−1) for crystal violet, outperforming the capacity of other similar adsorbents. The contact time needed to reach equilibrium was 40 min for both studied dyes. The Elovich equation is the most suitable model for describing the adsorption of methylene blue, while the general order model is better suited for the adsorption of crystal violet dye. Thermodynamic analyses revealed the adsorption process to be spontaneous, favorable, and exothermic, with physical adsorption involved as the primary mechanism. The obtained results suggest that sour cherry leaves powder can be a highly efficient, eco-friendly, and cost-effective adsorbent for removing methylene blue and crystal violet dyes from aqueous solutions. [ABSTRACT FROM AUTHOR]

This paper investigates an alternative cooling method for photovoltaic (PV) solar panels by using water spray. For the assessment of the cooling process, the experimental setup of water spray cooling of the PV panel was established at Sultanpur (India). This setup was tested in a geographical location with different climate conditions. It was found that the temperature of the panel decreased from 53 to 23 °C and the total power was increased by 15.3% by the water spray cooling. The effectiveness of the system is also increased by its cleaning effects. The efficiency of this solar PV is reduced with the increase of panel temperature. The experiments showed that the PV cell efficiency was dropped by 0.5% with an increase of 1 °C in panel temperature. However, the electrical efficiency of the panel was increased by 0.28%/0.2 °C of temperature drop by the single nozzle spray cooling. [ABSTRACT FROM AUTHOR]

As the drying zone deepens, outer surface layer of the product does not have time to be moistened, due to a small amount of moisture coming from the inside. It becomes dry, its temperature rises. The intensity of moisture transfer from the inner layers of the product depends on many parameters, including a moisture diffusion coefficient. The study aim is to create a methodology for determining the moisture diffusion coefficient within vacuum drying of fruits, by taking into account cracks, channels and capillaries formed in the dry layer of the product through the resistance coefficient to evaporation. The work essence consists in the determining of the moisture diffusion coefficient as a driving force, a difference between water activity and air humidity, by considering the resistance coefficient to evaporation, characterizing the effect of hydrodynamic resistance of the dried dry layer of the product. This approach was used to determine the moisture diffusion coefficient during vacuum drying of the Baiterek apple sort and the Zhazdyk pear sort of Kazakhstani selection. It was established that in the first period of drying the moisture diffusion coefficient decreases on average from 24,4∙10-7 m²/s to 13,2∙10-7 m²/s. The critical humidity for pear is 37.4 %, and for apple 35.1 %. As result of the formation of dry layer on the surface and subsequent layers, the moisture diffusion coefficient gradually decreases. In the second drying period, the moisture diffusion coefficient decreases from 5,42∙10-8 m²/s to 2,12∙10-8 m²/s. The work practical significance is related with the application of the obtained results in the determination of the optimal drying regime with maximum preservation of the product original quality. The proposed methodology can be used in the practice to study the moisture diffusion coefficient within vacuum drying of fruits, by considering the product properties and the hygroscopic parameters of the drying matter [ABSTRACT FROM AUTHOR]

The aim of this work is to study coal steam gasification with various methods of coal in-core treatment in FB using a newly developed thermodynamic calculation method. A calculational study of subbituminous coal steam non-catalytic gasification was carried out using four different methods of coal in-core treatment in single-vessel multisectional fluidized-bed gasifiers. A semi-empirical model based on the entropy maximization thermodynamic method and "restricted equilibria" based on previously obtained experimental data has been developed. Based on thermodynamic calculations, the effect of the leading thermochemical processes and operating parameters of the fluidized bed (temperature, fluidization number, steam/coal ratio feed rate) was revealed. New information was obtained regarding the composition of char and syngas at the gasifier outlet, the syngas heating value, and the cold gas efficiency of the steam gasification of Borodinskiy subbituminous coal char. The results indicate the possibility of significantly accelerating and improving non-catalytic steam gasification in fluidized bed gasifiers through the appropriate organization of in-core coal treatment. Based on the results obtained, the following recommendation is made—when designing multi-section and multi-vessel steam-blown gasifiers, the ratio of residence times should be set in favor of increasing the coal residence time in the steam-blown carbonization zone. Structurally, this can be achieved by increasing the volume and/or area of the steam-blown carbonization section (vessel). [ABSTRACT FROM AUTHOR]

[Display omitted] • A new biosorbent was prepared by immobilizing Auxenochlorella protothecoides microalgae within a sugarcane bagasse lignocellulosic matrix. • Response surface optimization for the synthesis process of immobilized microalgae. • The immobilization technique enhanced the biosorption of nickel by 32.25% at equilibrium compared with that of free Auxenochlorella protothecoides. • The immobilized microalgae has excellent removal of Ni(II). An efficient carcinogenic metal biosorbent was prepared by immobilizing the microalgae Auxenochlorella protothecoides (AP) within a sugarcane bagasse (SB) lignocellulosic matrix. The characterization of AP-SB as a proposed biosorbent was performed by various spectroscopic methods, including Fourier Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), and Thermo-gravimetric analysis (TGA/DTA). The immobilization technique enhanced the biosorption of nickel by 32.25% at equilibrium compared with that of free Auxenochlorella protothecoides. The maximum metal biosorption capacities of free and immobilized A. protothecoides were calculated to be 42.08 and 62.1 mg/g, respectively. The removal efficiency of nickel ions was evaluated with a Box‒Behnken factorial design using three parameters: pH solution, contact time, and biosorbent concentration. A maximum metal removal rate of 97.96% was obtained using the RSM-DF platform with the following optimal conditions: pH 5.06, biosorbent concentration of 1.6 g/L, and contact time of 53.33 min. The experimental equilibrium adsorption isotherms for the nickel bioprocess were analysed using sixteen models with two, three, and four parameters. An evaluation of the goodness of fit of various nonlinear regression isotherms indicated that the Fritz–Schlünder (IV) model was the most suitable model to describe the equilibrium curves; this model was selected based on the values of four error functions: the coefficient of determination (R²), the hybrid fractional error function (HYBRID), Marquardt's percent standard deviation (MPSD), and the average relative error (ARE). The thermodynamic factors and kinetics analysis demonstrated that the bioprocess was exothermic, favourable, and spontaneous at 298–318 K. Finally, the biosorption of nickel ions on SB-AP was explained by four proposed mechanisms based on the network structure of cellulose, lignin, N-acetyl-β-D-glucosamine, and β- d -glucosamine units. [ABSTRACT FROM AUTHOR]

Natural and artificial sorption of arsenic on iron hydroxides is one of the most important reactions controlling arsenic mobility in mine water and other water resource systems. Thermodynamic equilibrium modeling can be used to design and optimize water treatment systems as arsenic sorption is a function of speciation, dose, pH, Eh, and water composition. However, the effects of temperature on arsenic treatment systems have not been extensively considered in mine water quality investigations and treatment designs. Laboratory and field studies have shown that adsorption of arsenic oxyanions onto iron hydroxide particles is endothermic and the equilibrium concentration of arsenic in water is lower at higher temperatures and higher at lower temperatures. Data from two field sites are presented to investigate the effect temperature has on arsenic treatment. At a site in Canada, ferric sulfate coagulation is used to treat arsenic in tailings contact water when not frozen. The dosage of ferric sulfate is held constant but is much less efficient during spring thaw than in the summer. Thermodynamic modeling shows that the dosage must be increased in the spring to meet discharge water quality standards because the sorption equilibrium constant is temperature dependent. At another site in the Rocky Mountains of the USA, the USGS studied and modeled passive treatment of arsenic and other contaminants in AMD-affected stream flows without including temperature dependent sorption. Thermodynamic modeling was used to reexamine the effect of temperature on arsenic sorption onto iron hydroxide precipitates. [ABSTRACT FROM AUTHOR]

Over the years, RuIV(bpy)2(py)(O)2+([RuIVO]2+) has garnered considerable interest owing to its extensive use as a polypyridine mono-oxygen complex. However, as the active-site Ru=O bond changes during the oxidation process, [RuIVO]2+ can be used to simulate the reactions of various high-priced metallic oxides. In order to elucidate the hydrogen element transfer process between the Ruthenium-oxo-polypyridyl complex and organic hydride donor, the current study reports on the synthesis of [RuIVO]2+, a polypyridine mono-oxygen complex, in addition to 1H and 3H (organic hydride compounds) and 1H derivative: 2. Through 1H-NMR analysis and thermodynamics- and kinetics-based assessments, we collected data on [RuIVO]2+ and two organic hydride donors and their corresponding intermediates and established a thermodynamic platform. It was confirmed that a one-step hydride transfer reaction between [RuIVO]2+ and these organic hydride donors occurs, and here, the advantages and nature of the new mechanism approach are revealed. Accordingly, these findings can considerably contribute to the better application of the compound in theoretical research and organic synthesis. [ABSTRACT FROM AUTHOR]

This work presents effects of heat treatments at 300 °C, 400 °C and 500 °C for 1 h on structural/microstructural properties, transformation temperatures and some thermodynamic parameters of a Cu-12.4Al-2.5Fe-1Zr (wt%) HTSMA via XRD, SEM/EDX and DSC. Microstructure of the alloy contains 18R and 2H martensite phases, Cu9Al4 precipitates and voids. The results reveal that orientations of the 18R martensite, degree of long-range order, fractions of the Cu9Al4 precipitates, transformation temperatures and energies required for martensite nucleation and stored during martensitic transformation of the alloy change depending on the heat treatment temperature. As the heat treatment temperature raises up to 500 °C, both there have been shifts in the transformation temperatures of the alloy and energies required for transformations altered. Therefore, it is observed that the transformation hysteresis of the alloy increased to 111.95 °C and whereas the elastic energy stored during cooling decreases, the driving force required for the nucleation of the martensite phase at Ms increases. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the preparation of a low-cost biosorbent from tea wastes were for use as a natural carrier for the removal of acetic acid from aqueous solutions. In order to clarify the adsorption process, batch experiments were carried out to study operating parameters effect on the adsorption process such as: contact time (5-60 min); initial concentration of acetic acid (0.01-0.1 mol L-1) and temperature (15-35 °C). The experimental data were analyzed by Langmuir and Freundlich isotherm. The equilibrium is perfectly described by the Langmuir model (R²>0.99) with a maximum monolayer adsorption capacity of 20.16 mg g-1 and the calculated specific surface area is equal to 42.489 m² g-1. Kinetic study shows that the pseudo-second order well fitted the kinetic data. Thermodynamic parameters indicate that the adsorption process is feasible, spontaneous and exothermic. The results of the present study show that tea waste can be advantageously used as a low cost biosorbent for the removal of an acid from aqueous solutions. [ABSTRACT FROM AUTHOR]

Fig leaf, an environmentally friendly byproduct of fruit plants, has been used for the first time to treat of methylene blue dye. The fig leaf-activated carbon (FLAC-3) was prepared successfully and used for the adsorption of methylene blue dye (MB). The adsorbent was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and the Brunauer–Emmett–Teller (BET). In the present study, initial concentrations, contact time, temperatures, pH solution, FLAC-3 dose, volume solution, and activation agent were investigated. However, the initial concentration of MB was investigated at different concentrations of 20, 40, 80, 120, and 200 mg/L. pH solution was examined at these values: pH3, pH7, pH8, and pH11. Moreover, adsorption temperatures of 20, 30, 40, and 50 °C were considered to investigate how the FLAC-3 works on MB dye removal. The adsorption capacity of FLAC-3 was determined to be 24.75 mg/g for 0.08 g and 41 mg/g for 0.02 g. The adsorption process has followed the Langmuir isotherm model (R2 = 0.9841), where the adsorption created a monolayer covering the surface of the adsorbent. Additionally, it was discovered that the maximum adsorption capacity (Qm) was 41.7 mg/g and the Langmuir affinity constant (KL) was 0.37 L/mg. The FLAC-3, as low-cost adsorbents for methylene blue dye, has shown good cationic dye adsorption performance. [ABSTRACT FROM AUTHOR]

In this study, activated carbon (AC) obtained with apple peel was used for removal of Neutral Red (NR) from aqueous solutions. The characterization of AC was evaluated with the Brunauer-Emmett-Teller (BET), Fourier transform infrared spectra (FTIR), X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) analyses. Isotherm, kinetic, and thermodynamic parameters were determined for NR removal with AC. Eighteen isotherm models and eight kinetic models were analyzed for three temperatures and six initial dye concentrations. The experimental data best agree with the Langmuir model among the isotherm models, and the maximum adsorption capacity (qm) was calculated 142.857 mg/g at 318 K. It was determined that the pseudo-second-order (PSO) model was the best choice among the kinetic models with the highest correlation coefficients. The removal percentage of NR dye with AC obtained 82.13%, 84.79%, and 87.20% for 120 mg/L initial dye concentration at 298 K, 308 K, and 318 K, respectively. The negative free energy, enthalpy, and entropy values of adsorption obtained − 6386 J/mol, 46280 J/mol, and 165.48 J/mol.K for 20 mg/L NR concentration at 318 K, respectively. The results of this separation process shown spontaneous essence, and workability coinciding with the negative free energy and activation energy was found 13.651 kJ/mol. The assessment of the isotherm, kinetic, and thermodynamic results were evaluated with error functions. The highest correlation coefficient (R2) values and the lowest sum of squares (SS), sum of the square of error (SE), and mean square of error (MSE) values were determined with Langmuir isotherm and PSO kinetic models. This research showed that AC prepared from biomass can be used effectively for wastewater treatment using adsorption technique. [ABSTRACT FROM AUTHOR]

This paper presents a novel, quasi dimensional-model for the simulation of the combustion process in compression-ignition engines. The model discretizes with a multiple number of zones the in-cylinder air-fuel mass on fixed values of local equivalence ratio, with the charge stratification determined from a 2D reconstruction via a one-dimensional control-volume-based spray approach. Reacting multi-zones are further split into three conceptual sub-zones: liquid, unburnt vapor and burnt vapor, in which chemical reactions proceed according to a tabulated kinetics of ignition (TKI) model. This approach provides a simple methodological framework for the combustion of direct injection of virtually every kind of liquid fuel and relies on a detailed phenomenological chemical/physical link of jet's reacting phenomena. To account for engine geometry, a spray-wall interaction sub-model has been added to the axial spray. The model has been validated against experimental data and detailed CFD simulation results. First, the direct injection model (as a free jet) has been assessed with respect to ECN sprays A, C, and D experiments. For both the long injection and split injection cases, all the combustion phases are well predicted: premixed peak, mixing-controlled combustion, burn-out are seamlessly described and in good agreement with experimental and detailed CFD data. The wall interaction sub-model was validated with a suitable experiment where a reacting jet impinges on a mock-up wall inside a combustion vessel. Finally, the model has been validated against real heavy-duty engine experimental observations of 151 points of a complete engine map. The tuning of the model consists in two parameters, that are engine-specific, hence constant for the whole map. With these assumptions, the AHRR traces are well described in all simulated conditions. Mean predicted BSFC is only slightly underestimated (−2.3%), as it is the NOx production (−1.6%). [ABSTRACT FROM AUTHOR]

In this review, the authors conducted benchmarks for three thermodynamic models to analyze PSA-based medical oxygen concentrator (MOC) systems to allow for optimization and operational flexibility. PSA oxygen generator plants are good medical-grade oxygen sources, a crucial tool in healthcare from the primary to the tertiary level. However, they must be designed accordingly and properly operated, considering key design goals such as improving adsorbent productivity, improving oxygen recovery, and innovating to reduce unit size and weight. The importance of mapping the performance of various design and operating requirements or designs themselves on outlet product specifications and production effectiveness is outlined. Emphasizing optimal PSA design and operation, the authors suggest considering simulation-based optimization frameworks or high-fidelity modeling for the optimal layout and operation conditions of adsorption-based MOC systems. Notwithstanding, a simplified first-principles-based model with additional assumptions and simplifications generates a large volume of scenarios faster. Therefore, it represents a good approach for a feasibility study dealing with many options and designs or even the real-time monitoring of PSA operating conditions. All this paved the way for efficient translation into machine learning models and even deep learning networks that might be better suited to simulate the complex PSA process. The conclusion outlines that PSA-based plants can be flexible and effective units using any of the three models when properly optimized. [ABSTRACT FROM AUTHOR]

The use of new energy sources, such as geothermal energy, is rapidly expanding worldwide, and it is a viable alternative to fossil fuels. This paper proposes a geothermal power generation system (combined single flash geothermal cycle with transcritical carbon dioxide recovery cycle). To improve system performance, a recuperator is used to recover some of the heat loss. The proposed system simulation is performed in EES software and then validated by previous research. The proposed system is analyzed from the perspective of energy and exergy. The effects of the proposed system separator pressure, carbon dioxide turbine inlet pressure and carbon dioxide condenser outlet temperature on energy efficiency, exergy efficiency and system net power output have been investigated. Findings show that the proposed system in recovery mode has a net power output of 401.40 kW, energy efficiency of 53.6 percent, and exergy efficiency of 46.32 percent, which are significantly higher than the basic mode’s values of 149.9 kW, 2.39 percent, and 12.12 percent, respectively.

The growing global demand for fish has led to an increase in fish waste (FW) production, necessitating efficient waste management strategies. Pyrolysis is a promising way to convert fish waste into high-value products. To achieve optimal waste mass reduction and gain insights into the pyrolysis process, estimating kinetic parameters is essential. This study investigated the pyrolysis of FW, Sardinella fimbriata, a previously unexplored waste source, using a thermogravimetric analyser. The study determined an average activation energy value of 84–124 kJ/mol using model-free isoconversional methods including Flynn-Wall–Ozawa, Kissinger–Akahira–Sunose, and Starink, whereas pre-exponential factor values were predicted to be between 102 and 1011 s−1. Further analysis using Criado's reduced master-plot approach showed that the experimental curves for pyrolysis coincided with many different theoretical plots for reaction mechanisms, with a concentration on reaction-order models. The analysis of thermodynamic parameters showed positive values of enthalpy change and Gibbs energy change for S. fimbriata FW pyrolysis, suggesting that the process is endothermic and non-spontaneous, while negative values of entropy change were observed across all conversion degrees as a result of the breakdown of complex organic molecules into simpler compounds. This study provides insights into the feasibility of thermal processes and offers new guidance for FW waste management and resource recovery, expanding the understanding of pyrolysis kinetics and thermodynamics for fish waste treatment.

The use of synthetic compounds as corrosion inhibitor is diminishing due to strict environmental regulations and toxic effects of the compounds on human beings and the environment. Consequently, there exists the need to develop a new class of corrosion inhibitors with low toxicity, eco-friendliness and good efficiency. Therefore, this study investigates the inhibitory potential of Acalypha wilkesiana (AWAE) extract on mild steel in 1M HCl using weight loss method. Experiments were performed by varying immersion period, concentration of the inhibitor and temperature. The results obtained showed a decrease in the corrosion rate of mild steel as the extract concentration increases while the inhibition efficiency increases with extract concentration. Effect of temperature on the inhibition efficiency showed an increase in inhibition efficiency with rise in temperature. The adsorption of the inhibitor on the mild steel surface in acid solution was found to obey the Langmuir adsorption isotherm. Calculated thermodynamic parameters revealed that the mechanism of the corrosion inhibition may be due to the chemical adsorption of the phyto-constituents on the surface of mild steel. Kinetic treatment of the data followed a first order reaction and the half-life values of the metal increase with increase in the extract concentration. Preliminary investigation of the phytochemical constituents showed that Acalypha wilkesiana contains tannin, flavonoid, saponin, alkaloid, steroid , terpenoid and some other compounds in trace quantity. FTIR results indicate that AWAE contains O and N atoms in functional groups and aromatic ring which meet the general consideration of a typical corrosion inhibitor.

Abstract Methylene blue (MB) is a heterocyclic aromatic dye that is difficult to biodegrade due to its complex chemical structure. In this study, chemically prepared nano zero-valent aluminum (nZVAl) was investigated for the first time for one-step removal of MB from aqueous solutions under different experimental factors (pH, dosage, time, MB concentration, stirring rate, temperature, detergents, and ionic strength). The prepared nZVAl material was characterized using XRD, TEM, SEM, EDS, and FTIR. Results indicated that at an initial MB concentration of 10 mg/L, pH 10, nZVAl dosage 1.0 g/L, stirring rate 200 rpm, and temperature 30 °C, the removal efficiency of approximately 99.0% was achieved within an equilibrium time of 90 min. An improvement in MB removal efficiency was observed in the presence of inorganic salts, while the presence of detergents resulted in a reduction in MB removal efficiency. The isotherm adsorption data were best fitted by the Freundlich isotherm model (R 2: 0.9569), while the kinetic data were well described by the pseudo-second-order (PSO) model (R 2: 0.9999). Based on the thermodynamic study, the MB adsorption process is physically diffusion-controlled. The adsorption of MB onto nZVAl was accurately described using an artificial neural network (ANN) with a structure of 11–10–1 and R 2 of 0.97. The overall cost of scaling up the adsorption unit to be used for MB removal from aqueous solutions under the optimum conditions is about US$1.31/m3. Consequently, this study opens the door for other researchers to test nZVAl in treating real textile wastewater.

Hot dry rock has attracted broad attention due to its relatively high temperature and abundant resources. To match the power generation system suitable for low dryness hot dry rock geothermal fluid, this paper constructed four power generation systems: single stage flash system, double stage flash system, single stage flash combined organic Rankine cycle system and double stage flash combined organic Rankine cycle system. In the range of dryness 0∼0.3 and temperature 150∼200 °C, the matching characteristics between four power generation systems and geothermal fluids in hot dry rock with low dryness were studied. Taking the optimal net power output and exergy efficiency as objective functions, the performance of the four systems was optimized. In addition, the economic performance and environmental benefits of the system are compared. The results show that the temperature of hot dry rock geothermal fluid is positively correlated with the power generation performance, economic performance and environmental benefits of the four systems. In terms of power generation performance, the double stage flash combined organic Rankine cycle system has the best matching characteristics with geothermal fluids. For economic performance, double stage flash combined organic Rankine cycle system and double stage flash system have the highest matching degree when dryness is less than 0.1 and greater than 0.1, respectively. The environmental benefit of double stage flash combined organic Rankine cycle system is superior to the other three systems.

With the rapid development of the new energy automotive industry, consumers' requirements for the range of electric vehicles have been increasing. The Ni-rich ternary lithium-ion battery has become the most promising power battery in electric vehicles due to its high specific energy, but the battery system still faces the problem of poor performance at low temperature.The research progress on low temperature performance of Ni-rich ternary power battery in recent years was summarized in this review. The influence factors on the low temperature performance of Ni-rich ternary power battery were summarized emphatically. On the one hand, the effects of low temperature performance from thermodynamics were analyzed, including the structural change of the Ni-rich ternary cathode materials and graphite anode materials, electrolytic phase transformation and solvation structure changes, and glass transition of binder. On the other hand, rate controlling step in the low temperature discharge process in the Ni-rich ternary lithium-ion battery was summed up. According to this, main modification measures of low-temperature performance in Ni-rich ternary power battery were summarized. Low temperature electrolyte was designed by optimizing solvents, improving lithium salts and applying new additives. In order to improve the low temperature performance of electrode materials, three methods were mainly employed: substitution, surface modification and smaller material particle size. The remaining shortcomings of the research on low-temperature performance of the battery were summarized, and the research on the low temperature thermodynamic characteristics of batteries is not clear enough. In addition, the research methods for the low temperature kinetic process of batteries are single, and the influence of the reaction sequence in batteries is insufficiently understood.

This study investigates the role of the land surface on the precipitation produced by an elevated mesoscale convective system (MCS) in Iowa between 24–25 June 2015 during the Plains Elevated Convection at Night (PECAN) field campaign. Previous studies have shown a strong effect of low‐level atmospheric moisture on the location of this MCS. A series of semi‐idealized and realistic simulations with irrigation are conducted to understand the effect of moisture perturbations on the MCS precipitation displacement. In general, numerical simulations place the MCS east of the observed location. Adding moisture directly in the low‐level atmosphere in the semi‐idealized experiments reduces this displacement error. However, experiments with perturbed soil moisture result in drying over Iowa induced by moisture flux divergence from cooler low‐level temperatures and higher surface pressure, causing the MCS to move further to the east. The irrigation impact on low‐level moisture is highly dependent on the length of simulation period. Shorter simulations on the order of days generate similar drying over Iowa but the opposite is found for month‐long simulations. Despite the lack of low‐level moistening in the perturbed soil moisture and short‐term irrigation experiments, the sensitivity to low‐level moisture is similar in all runs. More low‐level moisture generates a more convectively unstable environment with less inhibition and a lower level of free convection that leads to more rapid MCS development and a change in MCS location. Plain Language Summary: This study looks at how the land surface affects the precipitation produced by a cluster of thunderstorms (called an elevated mesoscale convective system, or MCS) that happened in Iowa between June 24–25, 2015. We use semi‐idealized simulations to study the effect of moisture on the location and amount of precipitation from the storm. We find that adding moisture directly to the air close to the ground makes the storm form closer to its observed location, while changes to the moisture in the soil can make the storm move further away. The impact of irrigation on the moisture near the ground depends on how long the simulation is run for. Overall, the study finds that more moisture in the air close to the ground leads to a more unstable atmosphere that causes the storm to form more quickly that matches better with observations. Key Points: The mesoscale convective system (MCS) timing and location are sensitive to low‐level atmospheric moistureAdding soil moisture is not equivalent to adding atmospheric moisture because it cools temperature and induces low‐level divergenceShort‐term irrigation simulations dry atmospheric moisture and move the MCS to the east, but long‐term irrigation does the opposite [ABSTRACT FROM AUTHOR]

Cosolvency is a widely used method employed to enhance drug solubility. There are limited data on the solubility of atorvastatin calcium (ATC). The aim of this work is to determine ATC solubility in glycerol + water and 2-propanol + water mixtures at several temperatures (293.15, 298.15, 303.15, 308.15 and 313.15 K). The apparent thermodynamic properties of the ATC dissolution process including Gibbs free energy (ΔG°sol), enthalpy (ΔH°sol) and entropy (ΔS°sol) were calculated. The ATC solubility in various concentrations of the anionic, cationic and non-ionic surfactant was explored. The drug is most efficiently dissolved in sodium lauryl sulphate (SLS). Tween 20 did not cause any increment in drug solubility. Benzalkonium chloride may form an insoluble salt with ATC anion resulting in a decrease in drug solubility. Cosolvency data were correlated by Jouyban–Acree and Jouyban–Acree–van't Hoff equation. [ABSTRACT FROM AUTHOR]

As the most widely used vanadium intermediate alloy, ferrovanadium is mainly prepared by the self-propagating high-temperature synthesis (SHS) process with the advantages of short process and large heat release. However, there is a trade-off between the amount of reduction agent of Al and the product quality of ferrovanadium, which is caused by the thermodynamic equilibrium limitation of the reduction between Al and vanadium oxides. The reasonable adjustment of the trade-off has become an urgent problem to be solved for the preparation of high-quality ferrovanadium. In the present work, the thermodynamic equilibrium for the reduction limitation using Al as reducing agent has been thoroughly analyzed with the reference to the equilibrium phase diagram. It was found that the theoretical reduction limitation of total vanadium (T.V) in slag was decreased from 4.08 wt.% to wt. 0.86 wt.% when the Al content in alloy reached 2.0 wt.% at 1800 °C. The vanadium in slag was mainly presented in the form of MgV 3 O 8 and coexisting with other phases of MgAl 2 O 4 , CaAl 2 O 4 , CaAl 4 O 7 , CaAl 12 O 19. With the purpose of further decrease the high Al concentration in alloy and vanadium loss in slag, an improved SHS-EAH process was implemented by multi-stage gradient aluminum addition coefficient pattern, the average vanadium content in slag was reduced from 1.82 wt.% to 0.83 wt.%, while the aluminum content in FeV50 alloy was decreased from 1.5 wt.% to 0.4 wt.%. The SHS-EAH process was proved to be a better process with improved yield and quality for the preparation of ferrovanadium. [ABSTRACT FROM AUTHOR]

Garlic peel, an agriculture by-product, was modified using nitric acid as a simple method. Therefore, this study aims to remove and/or minimize of Cr(VI) ions from aqueous media using HNO3 modified garlic peel (HNO3-GP). Scanning electron microscopy, energy-dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy analysis of the HNO3-GP, as a solid phase extractor, were performed. The operational parameters of the adsorption such as solution pH, initial concentration of analyte, adsorbent dose, temperature and shaking time were performed. The equilibrium data of Cr(VI) showed a better fit with Langmuir isotherm model with R² = 0.9956 and adsorption capacity equals to 31.7 mg/g. Moreover, the kinetic data of analyte retained revealed that the present system fitted well with pseudo-second-order kinetic model (R² = 0.9918). Thermodynamic studies indicated that the retention step was endothermic and spontaneous in nature depending on the value of ΔH° (118.292 J/mol) and ΔG° (–117.41 kJ/mol). The positive value of ΔS° (394.39 J/mol·K) confirmed that the biosorption process was carried out with high randomness on the surface of HNO3-GP. The results showed that the proposed adsorbent (HNO3-GP) provides an effective and economical approach in highly minimization or almost removal of Cr(VI) ions from the aqueous solution. [ABSTRACT FROM AUTHOR]