Thermodynamic Investigation Research Articles

Carbon nanotube/bentonite @ polyvinylidene fluoride tri-flouro ethylene nanocomposite matrix for surpior elimination of carcinogenic dye from wastewater

Abstract This study examines the sorption behavior of Congo Red (CR) dye from water-based solutions using a synergistic nanocomposite made of Bentonite (BT), multi-walled carbon nanotubes (MWCNTs), and a Poly (vinylidene fluoride tri-flouroethylene) (P(VDF-TRFE)) polymer matrix with exceptional adsorption capacity for the selective removal of Congo red dye from aqueous solutions. This is done in order to address the urgent concerns surrounding the health and environmental implications of CR dye. Utilizing modern analytical technique such as FTIR, XRD, SEM, TEM, and TGA, the adsorption physicochemical interaction and nanocomposite manufacturing were carefully investigated, offering thorough insights into the composite's general properties. Nanocomposite structures of between 31 and 37 nm in diameter were discovered by TEM examination. The adsorption process was pH dependent, reaching a peak removal effectiveness of 94.5% at pH 3.0. The correlation coefficients obtained from kinetic modeling using pseudo-first-order and pseudo-second-order equations were 0.97389 and 0.96802, respectively, suggesting that the adsorption mechanism adhered to first-order rate kinetics. Thermodynamic investigation revealed an exothermic and spontaneous reaction, with a negative ΔG value between − 7.45 and − 7.95 J/mol. The nanocomposite outperformed the capacities reported for individual components in earlier investigations, with an impressive monolayer sorption capacity (qmax) of 143.88 mg/g. As a result, there is great potential for this innovative nanocomposite to be a very successful adsorbent for treating industrial wastewater. Graphical Abstract

Multi-walled carbon nanotubes/TiO2/Chitosan nanocomposite for efficient removal of malachite green dye from aqueous system: A comprehensive experimental and theoretical investigation.

This study presents the preparation, characterization, and application of a novel Multi-walled carbon nanotubes/TiO2/chitosan (MWCNT/TiO2/CS) nanocomposite, prepared using a hydrothermal method, for the removal of malachite green (MG) dye from aqueous solutions. Adsorption studies revealed optimal dye removal within 15min of adsorption equilibrium time, with maximum removal efficiency of 98.53% at pH7.0, dose 0.4g/L and 298K. Isotherm studies showed the Langmuir model best described the adsorption equilibrium data with maximum monolayer adsorption (qm) value was found to be 269.98mg/g at 298K. Kinetic analyses favored the pseudo-second-order model with qcal value was found to be 201.6mg/g at Co=100mg/L. Thermodynamic investigations indicated an exothermic, spontaneous adsorption process. Seven successful adsorption-desorption cycles were achieved using HCl as an eluent (97.65% desorption). Theoretical reactivity parameters derived from DFT calculations corroborated experimental findings, elucidating the molecular-level mechanisms underlying the efficient adsorption of MG onto the MWCNT/TiO2/CS surface. The strong electrophilic nature and electron-accepting character of the MG molecule, along with its ability to form electronic interactions, explain its high adsorption affinity. These findings demonstrate the potential of MWCNT/TiO2/CS nanocomposite as an effective and sustainable solution for MG dye removal from aqueous environments.

Electrocatalytic performance of transition metal mono-carbides (TM: CrC, FeC, MnC, TiC, VC) decorated on palladium-encapsulated fullerenes (TM-Pd@C60) for hydrogen evolution reaction (HER): A DFT perspective

The search for efficient and cost-effective electrocatalysts for the hydrogen evolution reaction (HER) is critical for advancing renewable energy technologies. This study employs density functional theory (DFT) at the MN12-SX/GenECP/Def2svp/LanL2DZ computational method to investigate the electronic, structural, and catalytic properties of modified fullerene (C60) systems encapsulated with palladium (Pd) and doped with transition metal carbides: CrC, FeC, MnC, TiC, and VC. Frontier molecular orbital (FMO) analysis reveals significant changes in the HOMO-LUMO gap upon doping, indicating enhanced electronic conductivity essential for catalytic activity. The lowest energy gaps 0.081 eV for MnC–Pd@C60 and 0.096 eV for VC-Pd@C60 were observed thus showing their readiness in terms of electron transfer. HER activity was assessed through the calculation of Gibbs free energy changes (ΔGH) for hydrogen adsorption. The results highlight TiC–Pd@C60, FeC–Pd@C60, and CrC–Pd@C60 as having optimal ΔGH values close to zero, suggesting their superior catalytic performance. Structural analysis confirms the stability of these doped systems, with minimal distortions observed in the fullerene framework upon metal encapsulation and doping. Vibrational analysis revealed that Pd@C₆₀ complexes show reduced M − C vibrations and the formation of M − H bonds, indicating efficient hydrogen adsorption, especially in MnC–Pd@C₆₀ and VC-Pd@C₆₀. Thermodynamics investigation show MnC–Pd@C₆₀ and VC-Pd@C₆₀ to exhibit highly exothermic and spontaneous hydrogen adsorption. Overall, Ti, Fe, and Cr-based catalysts show weaker interactions, which might favor the desorption step in HER. On the other hand, catalysts with V and Mn show strong hydrogen interactions via the Tafel step, which might benefit initial hydrogen adsorption but could require optimization to ensure efficient hydrogen release.

Full recovery of brines at normal temperature with process-heat-supplied coupled air-carried evaporating separation (ACES) cycle

Conventional air-carried evaporating separation (ACES) technology, to achieve complete separation and recovery of water and salt in brine, tends to necessitate heating air above a critical temperature (typically>90 °C). In this paper, a novel concept of process-heat-supplied and an ACES cycle with this technique is proposed. A comprehensive thermodynamic analytical investigation is conducted. The results indicate that at heat source supply temperature Tsupply of only 45.17 °C, this novel unit is capable of achieving complete separation of water and salt from 5 wt% concentration brine. Meanwhile, thermodynamic mechanism analysis reveals that sufficient process-heat-supplied affords the fluid self-adaptive regulation on the driving potential of heat and mass transfer, thus circumventing traditional heat and mass transfer limitation. Additionally, a solar ACES system with process-heat-supplied incorporating heat pump is further proposed. For this system, theoretical evaporation rate for unit area of solar irradiation me-solar = 2.23 kg/(m2·h), integrated solar utilization efficiency ηi = 188%; while considering overall losses me-solar = 1.41 kg/(m2·h), ηi = 95.2%.

Disruption of Molecular Interactions between the G3BP1 Stress Granule Host Protein and the Nucleocapsid (NTD-N) Protein Impedes SARS-CoV-2 Virus Replication.

The Ras GTPase-activating protein SH3-domain-binding protein 1 (G3BP1) serves as a formidable barrier to viral replication by generating stress granules (SGs) in response to viral infections. Interestingly, viruses, including SARS-CoV-2, have evolved defensive mechanisms to hijack SG proteins like G3BP1 for the dissipation of SGs that lead to the evasion of the host's immune responses. Previous research has demonstrated that the interaction between the NTF2-like domain of G3BP1 (G3BP1NTF-2) and the intrinsically disordered N-terminal domain (NTD-N1-25) of the N-protein plays a crucial role in regulating viral replication and pathogenicity. Interestingly, the current study identified an additional upstream stretch of residues (128KDGIIWVATEG138) (N128-138) within the N-terminal domain of the N-protein (NTD-N41-174) that also forms molecular contacts with the G3BP1 protein, as revealed through in silico analysis, site-directed mutagenesis, and biochemical analysis. Remarkably, WIN-62577, and fluspirilene, the small molecules targeting the conserved peptide-binding pocket in G3BP1NTF-2, not only disrupted the protein-protein interactions (PPIs) between NTD-N41-174 and G3BP1NTF-2 but also exhibited significant antiviral efficacy against SARS-CoV-2 replication with EC50 values of ∼1.8 and ∼1.3 μM, respectively. The findings of this study, validated by biophysical thermodynamics and biochemical investigations, advance the potential of developing therapeutics targeting the SG host protein against SARS-CoV-2, which may also serve as a broad-spectrum antiviral target.

Binding Strength and Transport Kinetics of Organic Dyes into Different Live Diatoms Using Second Harmonic Scattering Spectroscopy.

Dye-contaminated wastewater poses serious environmental risks to ecosystems and human health. Diatoms, algae with nanoporous frustules (cell walls), offer promising potential for wastewater remediation due to their high surface area and adsorption properties. While dead diatom biomass is well-studied for biosorption, research on living diatoms' bioaccumulation and biotransformation potential is limited, with gaps in kinetic and equilibrium modeling of dye adsorption. Here, we analyzed the adsorption of crystal violet (CV) dye onto living Phaeodactylum tricornutum (P-cell) and Navicula cryptocephala var. veneta (N-cell) diatoms by characterizing the physiochemical properties of the species' outer surfaces and monitoring the adsorption of CV using surface-specific second harmonic scattering (SHS) spectroscopy. Direct monitoring of dye adsorption, rather than its removal from the solution, enables a more accurate investigation of adsorption kinetics and thermodynamics, revealing strong correlations with the cell surface structure and composition. We found that the N-cell has a greater adsorption capacity for CV than the P-cell, though with slightly less favorable adsorption free energy. Ionic strength could impact uptake capacities, likely due to competition between metal cations and the dye cation as well as surface screening. SHS experiments revealed a simple adsorption process for N-cells, while P-cells exhibited a multistep process involving CV transport through thinner, nonporous cell walls to the plasmic membrane, contributing to favorable adsorption free energy. The thicker, porous walls of N-cells provided more surface sites, increasing the capacity, while P-cells facilitated deeper uptake. Ionic strength had only a significant effect on adsorption capacity, not adsorption free energy, reflecting the intricacies that govern adsorption and uptake by living organisms. The comprehensive analysis presented herein demonstrates great potential for diatoms to be used as biosorbents in dye remediation and provides systematic relationships between the structure and function of diatom cell walls, which will inform the use of tailored species for more efficient remediation.

Highly efficient removal of Pb2+ from aqueous solution using polyaniline-cobalt composite nanorods: Kinetics, isotherm and mechanistic investigation.

Nanosized cobalt (Co) particles exhibit unique chemical, magnetic, electronic, and catalytic properties. Like nanoscale metallic iron, nanostructured Co and its composite nanostructures also show significant potential for the removal of toxic metal cations from water and wastewater. To explore this potential, composite nanorods (CNRs) of nanosized Co immobilized polyaniline (PANI) nanorods (NRs) matrix (PANI-Co CNRs) were synthesized and effectively applied for the treatment of lead ions (Pb2⁺), serving as a model for heavy metal pollutants in water bodies. Physico-chemical characterization of PANI-Co CNRs revealed that weak ferromagnetic Co nanoparticles (NPs) were effectively deposited onto the surface of the PANI NRs. The enhanced surface properties and superior reactivity of PANI-Co CNRs resulted in greater Pb2⁺ removal efficiency compared to their individual components. The adsorption kinetics were notably rapid, with the time required to reach equilibrium varying between 60 and 150 minutes for initial concentrations ranging from 50 to 150 mg/L, all at a pH of 5.0. The isotherm data revealed an impressive Pb2+ adsorption capacity of 1130 mg/g at 25 °C, as determined using the non-linear Langmuir model. Exothermic and spontaneous Pb2+ removal process was deduced from the thermodynamic investigations. Among co-contaminating metal ions, only Cu2+ ions significantly affected the Pb2+ removal performance of the PANI-Co CNRs, implying its possible applications in decontaminating industrial effluent laden with various metal ions. Mechanistic investigation revealed that the treatment process primarily involves the adsorption and precipitation of Pb2+ onto the surface of PANI-Co CNRs, followed by its subsequent reduction to form metallic Pb (Pb0).

A novel amidoxime-functionalized covalent organic framework adsorbent for efficient lead ion removal: synthesis and adsorption mechanism

Lead ions are highly toxic heavy metal ions and Pb(Ⅱ) in wastewater threatened seriously human health and environment. Therefore, an effective adsorbent must be developed to remove lead ions from wastewater. In this study, a polycrystalline amidoxime covalent organic framework (DBCC-NHOH) is synthesized by a post-modification method for the elimination of lead (II) from wastewater. The successful preparation of adsorbent (DBCC-NHOH) is demonstrated by the oxygen appearance in SEM-EDS pattern and conversion of -CN to C=N-O and C-N in the FT-IR pattern. DBCC-NHOH is a crystalline porous material and its pore size, specific surface area and pore volume are 3.419nm, 28.154 m2/g and 4.2ⅹ10-8 m3/g respectively. The optimum conditions for the adsorption of Pb(II) by DBCC-NHOH are temperature 298K, time 180min, and pH 5. The maximum adsorption of DBCC-NHOH was 221.37mg/g. Kinetic and thermodynamic investigations indicate that adsorption of Pb(II) by DBCC-NHOH is a monolayer chemisorption and exothermic process. Selectivity experiments indicate that DBCC-NHOH can adsorb Pb(II) efficiently and selectively in complex multi-ion systems. In addition, the adsorption percentage of DBCC-NHOH remained up to 83.20% after five adsorption-desorption experiments. The XPS and FT-IR analyses and DFT results indicated that DBCC-NHOH utilized amidoxime function group to realize the high efficiency of Pb(II) adsorption by electrostatic attraction and chelation.

Bioassay-guided separation of antioxidants in Blaps rynchopetera Fairmaire and their theoretical mechanism

Blaps rynchopetera Fairmaire is a medicinal insect with a wide range of biological activities. Some of its activities, including anti-cancer and anti-inflammatory activities, are closely related to antioxidant capacity. In this study, a method was established to investigate components and theoretical mechanism of antioxidant from B. rynchopetera. As a result, two antioxidants were obtained by bioassay-guided separation and identified as 4-(2-hydroxyethyl)-1,2-benzenediol and 4-ethylbenzol-1,3-diol. Their EC50 were 20.20 ± 0.30 μM and 22.90 ± 1.30 μM for ABTS·+ scavenging, and 153.00 ± 2.00 μM and 301.00 ± 3.00 μM for DPPH· scavenging, respectively. The thermodynamic investigation indicated that the 2-OH of 4-(2-hydroxyethyl)-1,2-benzenediol and the 1-OH of 4-ethylbenzol-1,3-diol were more susceptible to be attacked by free radicals. They tended to exert antioxidant effects via the sequential proton loss electron transfer mechanism in polar media, whereas the hydrogen atom transfer mechanism was more likely to occur in non-polar media. In addition, frontier molecular orbital theory and energy barrier analysis suggested that 4-(2-hydroxyethyl)-1,2-benzenediol was more likely to react with DPPH·. These results confirmed that 4-(2-hydroxyethyl)-1,2-benzenediol had better antioxidant potential.

Thermodynamic and kinetic investigation on crystallization of photosensitive glass-ceramics via molecular dynamics

Photosensitive glass-ceramics serves as a crucial support for advancement of integrated circuits in post Moore era. Nevertheless, current research lacks an in-depth discussion of crystallization and nucleation mechanisms induced by nucleating agents. Here, we select new AgSbO3 nucleating agents and conduct a detailed thermodynamic and kinetic investigation of its promoting effects in Li2SiO3 using first-principles molecular dynamics. Statistical results from pair distribution functions indicate that in the presence of AgSbO3 nucleating agents in Li2SiO3, the structure tends to exhibit a more crystalline distribution. The diffusion coefficient of Li ions in AgSbO3–Li2SiO3 is 0.47 × 10–6 cm2/s, which is one-tenth of the value of Li ions in amorphous Li2SiO3. Additionally, a molecular dynamics approach was employed to screen and analyze motion trajectories of 16 lithium ions. All of these data suggest that AgSbO3 nucleating agents can accelerate crystallization of Li2SiO3. This work provides an atomic-scale discussion of nucleating agents' effects in photosensitive glass-ceramics.

Ibuprofen photodegradation promoted by ZnO and TiO2-P25 nanoparticles: A comprehensive kinetic, reaction mechanisms, and thermodynamic investigation

Photocatalytic activity, reaction kinetics, modeling, and thermodynamics of commercial TiO2-P25 and ZnO nanoparticles (NPs) for ibuprofen (IBU) photodegradation were investigated. Photodegradation experiments were performed in a batch reactor under UV irradiation. The photodegradation performances of TiO2-P25 and ZnO NPs were further studied and modeled under different operation conditions, by varying the reaction temperature, catalyst bulk density, and the initial concentration of the IBU solution. The descriptive kinetic models for the experimental data were tested, through the estimated kinetic parameters, together with the statistical information, revealing that the reaction rate in the case of TiO2-P25 is of first order while the ZnO NPs follow second-order kinetics with respect to IBU. The photodegradation mechanisms for both TiO2-P25 and ZnO NPs were determined to be Langmuir-Hinshelwood and Eley-Rideal, respectively. Thermodynamic parameters were assessed, particularly, changes in Gibbs free energy, enthalpy, and entropy indicating the efficient photodegradation performance of these NPs.

Silica nanoparticles@folic acid (SNPs@FA) nanocomposite for the effective removal of Hg(II) from aqueous solution: insight into physicochemical properties, adsorption modelling, isotherm, kinetic, and thermodynamic investigations

ABSTRACT This study involved the preparation and utilisation of silica nanoparticles functionalised with folic acid (SNPs@FA) nanocomposite in the adsorptive removal of Hg(II) from aqueous solutions before its spectrometric analysis. Different characterisation techniques were employed to comprehensively assess the different physicochemical properties of the prepared adsorbent, such as elemental analysis, FTIR, SEM, TEM, XRD, TGA, BET, and pHpzc. Investigations were conducted into the variables influencing the adsorption process, such as pH, contact duration, adsorbent dosage, and Hg(II) concentration. It was found that a pH of 7 was ideal, while adsorption equilibration took 80 min. The Langmuir model suited the experimental data well, and 129.03 mg/g of Hg(II) was the maximum adsorption capacity. The kinetic data obtained from the experiments exhibited a remarkable alignment with the pseudo-second-order model. Furthermore, the computed thermodynamic characteristics provided compelling evidence that the adsorption process was endothermic and spontaneous. The recommended process was effectively used to recover Hg(II) that had been added to some real water samples. The regeneration investigation using potassium iodide demonstrated the remarkable regenerative power of the manufactured adsorbent. Finally, the obtained results in this work showed that silica nanoparticles@folic acid nanocomposite is a very efficient and environmentally safe adsorbent and can be used for cleaning mercury-contaminated water.

Thermodynamics of black holes featuring primary scalar hair

In this work, we embark on the thermodynamic investigation concerning a family of primary charged black holes within the context of shift and parity symmetric Beyond Horndeski gravity. Employing the Euclidean approach, we derive the functional expression for the free energy and derive the first thermodynamic law, offering a methodology to address the challenge of extracting the thermal quantities in shift-symmetric scalar tensor theories characterized by linear time dependence in the scalar field. Following the formal analysis, we provide some illustrative examples focusing on the thermal evaporation of these objects. Published by the American Physical Society 2024

A dielectric, thermodynamic and volumetric investigation for heteromolecular hydrogen bonding in 2-ethoxyethanol and ethanol binary mixture

ABSTRACT The dielectric, thermodynamic and volumetric measurements of neat 2-ethoxyethanol, neat ethanol and their binary mixtures have been carried out using time domain technique at 10°C–25°C with a variation of 5°C. Various dielectric parameters are calculated from complex dielectric spectra and are used to compute Kirkwood correlation factor, Bruggeman factor and activation thermodynamic parameters. These parameters are used to predict heteromolecular hydrogen bonding between associating molecules. The classical and non-classical type H-bonding interactions among the molecules are predicted using FT-IR spectroscopy.

An Efficient Analytical Method for Determining Transition Temperatures in Core‐Shell Spin Crossover Nanoparticles Described by an Extended Ising‐Like Model

AbstractThis contribution is dedicated to the analysis of the size and interaction parameters effects on the thermal properties of square‐shaped cross‐spin transition core‐shell nanoparticles. The present study is carried out by varying the shell size at fixed core size and vice versa. In this problem, the core and shell are active from the spin transition point of view, while having different properties in terms of ligand field (transition temperatures) and interactions. The resulting nanoparticle is described by an Ising‐type model including the three interaction parameters JCC, JSS and JCS coupling core‐core, shell‐shell and core‐shell sites, respectively. The thermodynamic investigations have been carried out in 3 different ways: (i) by Monte Carlo Entropic Sampling (MCES) for small size nanoparticles ( ) (ii) by usual Monte Carlo Metropolis for higher dimensions (iii) by an analytical method deducing the equilibrium temperature of the system from the various local environments. We demonstrate that, as long as a clear plateau region occurs in the thermal‐dependence of the high‐spin fraction, an excellent agreement is obtained, allowing to predict analytically the evolution of the transition temperatures. The limitations of the method are discussed in the case of strong interference between the thermal dependences of the core and shell.

Investigation of structural, IR spectral, thermodynamics and excitation property alterations in (AlN)12 cluster under external electric fields

Investigation of structural, IR spectral, thermodynamics and excitation property alterations in (AlN)12 cluster under external electric fields

Synthesis, characterization and study of Sb(Ⅲ) adsorption from aqueous solution by iron-aluminum pillared attapulgite

In this study, a simple, environmentally friendly and inexpensive adsorbent for Sb(III) in aqueous solution was prepared by the copolymerization method using attapulgite as the matrix, FeCl3 and AlCl3 as the metal sources. The morphology and structure of iron-aluminum pillared attapulgite were analyzed through various characterization methods. The conditions and influencing factors of iron-aluminum pillared attapulgite preparation and Sb(III) adsorption were studied. The saturated adsorption capacity of Sb(III) could reach 60.44 mg·g−1 for 180 min at pH 7 and 298 K. The adsorption process is conformed to Langmuir isothermal model and pseudo-second-order kinetic model, and the thermodynamic investigation suggested a spontaneous and endothermic adsorption process. It was revealed by X-ray photoelectron spectroscopy analysis and Zeta potential analysis that Sb(III) was first electrostatically adsorbed by the adsorbent, part of Sb(III) was oxidized to Sb(V) by Fe(III) and then antimony was complexed with iron and aluminum hydroxides to form surface complexes. In addition, a small amount of antimony migrated through intra-particle diffusion into the internal micropores and reacted with hydroxyl groups. Most coexisting components under the chosen conditions had no influence on Sb(III) adsorption, and PO43−, AsO33−, C6H8O7 and H2C2O4 had a negligible effect. However, the adsorption capacity of over 90 % without interference showed that the material has a strong selectivity for Sb(III) adsorption. The findings of the desorption experiment showed that the adsorption product has a considerable degree of desorption at increased hydrochloric acid concentrations. It may be concluded that the adsorption product is more stable in the overall polluted water environment since the actual acidity of the polluted water environment is significantly lower than the desorption experiment acidity. Overall, iron-aluminum pillared attapulgite has great potential for application in removing Sb(III).

Isotherm, kinetic, and thermodynamic studies of adsorption of copper (II) and nickel (II) ions using low‐cost treated orange peel from aqueous solutions

AbstractThe aim of this study was to utilize processed orange peel waste (TOP) as an adsorbent to remove Cu(II) and Ni(II) ions from aqueous solutions. As a result of systematic experiments to determine the optimal conditions, it was determined that the most suitable conditions for the effective removal of Cu(II) ions were 400 mg/L initial concentration, 100 min contact time, 0.2 g adsorbent dosage, and a solution pH of 5.92. Similarly, the optimal conditions for the removal of Ni(II) ions were determined by systematic experiments to be 300 mg/L initial concentration, 0.2 g adsorbent dosage, 100 min contact time, and a solution pH of 6.19. The systematic experiments also included further investigation of the surface properties of TOP, and promising results were obtained by tests at three different temperatures (298, 308, and 318 K). The adsorption capacities for Cu(II), Ni(II), and Ni(II) were determined as 72.99, 75.18, and 76.33 mg/g, 42.55, 44.44, and 46.29 mg/g, respectively. Further analysis of the adsorption kinetics revealed that the pseudo‐second‐order model accurately represented the experimental data for both ions. Thermodynamic investigations provided strong evidence that the adsorption process of these noble metal ions on TOP is endothermic and spontaneous. The results of this study emphasize that TOP, with its low cost, easy‐to‐use nature, and high adsorption capacity, can be considered a long‐term solution for environmental remediation and water treatment in sustainable engineering applications.

A theoretical thermodynamic investigation on solar-operated combined electric power, heating, and ejector cooling cycle driven by an ORC turbine waste heat, tri-generation cycle system

The current study investigated a solar thermal power plant to simultaneously produce multiple energy outputs, including electric power, process heating, and cooling. This integrated approach aligns with the concept of a tri-generation system, where three different forms of energy are produced from a single source. The study involves a parametric analysis, where the impact of each influencing parameter including, turbine inlet temperature, and turbine inlet pressure is systematically varied with DNI ranging from 600 W/m2 to 1000 W/m2 to understand its effects on both first-law and second-law efficiencies. Further, the exergy analysis shows the irreversibility's occur within the system. Notably, the central receiver and heliostat are identified as major sources of exergy loss. The comparison to a combined power and heating (CPH) cycle without an ORC-ejector indicates that the additional technologies significantly contribute to improving the system's performance, approximately 3.97 % and 2.3 % for both efficiencies, respectively.

Hydration behavior of D-calcium pantothenate (vitamin B5) in the presence of sugar-based deep eutectic solvents at different temperatures: experimental and theoretical study

Considerable efforts have been devoted in recent years to enhancing the efficacy medicinal substance, leading to the discovery of innovative drug formulations and delivery techniques. The successful design of these processes necessitates a profound understanding at the molecular level of how these substances interact with biological membranes. Thorough thermodynamic investigations provide invaluable insights into these interactions and aid in selecting suitable compounds for pharmaceutical production. This study aims to determine the density and speed of sound for D-calcium pantothenate in mixtures of water and deep eutectic solvents (DESs), specifically choline chloride/sucrose, choline chloride/ glucose, and choline chloride/ fructose (with 2:1 molar ratio) over a temperature range of 288.15 K to 318.15 K under atmospheric pressure. In order to predict the behavior of molecules, COSMO model (the Conductor-Like Screening Model) offer complementary strengths in quantum chemistry. This approach allows for calculating solvation free energies, making it ideal for predicting properties like solubility, where understanding solvent-solute interactions is crucial. By correlating the measured parameters using standard relationships, important partial molar parameters such as apparent molar volumes and apparent molar isentropic compressibility are calculated. Additionally, apparent molar isobaric expansion, and Hepler’s constant are derived from the density and speed of sound data. The experimental apparent molar volumes, and apparent molar isentropic compressibility data is fitted to the Redlich-Meyer equation to obtain significant quantities such as standard partial molar volume, and partial molar isentropic compression. The comprehensive thermodynamic analysis of this studied system holds immense significance for advancements in the pharmaceutical industry.