Search Results (298)

Due to the necessity of decarbonising and transforming the Polish energy mix, topic of using nuclear power plants as one of the key low-carbon generation sources is returning to the public debate. This paper compares a large, system-wide AP1000 nuclear power plant with a new concept based on small modular reactors (SMRs), specifically NuScale 60 MW_e. Computer models of secondary loops of the generating units were used for the analysis, and basic operating parameters were determined. A consistent modelling approach was used to evaluate technical, thermodynamic, and economic indicators. As a result, a relationship between total capital expenditures and unit electricity generation cost was developed. For example, if the investment outlays, taking into account the freeze, for a large-scale nuclear power plant are USD 8 billion, then the investment outlays for an SMR power plant should be below USD 0.4 billion in order to ultimately ensure a lower or equal unit discounted cost of electric energy generation. Assuming stable power demand, the AP1000 reactor power plant remains the most cost-effective technology, offering favourable economies of scale. However, modular units are characterised by shorter lead times and greater flexibility of application in different areas of the energy industry. Therefore, in the decarbonisation process, it is essential to develop both analysed technologies in parallel. Full article

Background/Objective: In the pursuit of identifying novel therapeutic agents against breast cancer, a major priority is finding agents that effectively and safely inhibit the signaling pathways sustaining cancer cells. To better focus research efforts in validating such candidates, this in silico study assessed the pharmacokinetic profiles, thermodynamics, and binding affinity of chlorogenic acid and cinnamaldehyde with the upstream mediators of the Akt pathway implicated in breast cancer cells. Methods: Various software and online tools were used to conduct molecular docking of the small molecules with the proteins PI3K, Akt, and PDK1, and to examine their absorption, distribution, metabolism, elimination, and toxicity (ADMET) profile. Results: The results show strong binding energy (all within the range of those of FDA-approved drugs) and thermostability between the compounds and the proteins. The phytochemicals were predicted to have moderate oral bioavailability and tissue distribution, and were identified as substrates of drug metabolizing enzymes, but not deactivated. Conclusion: Although these predictive data warrant confirmation in a biological system, they suggest that the compounds have good pharmacokinetics and are strong inhibitors of the Akt pathway, with great potential to shut down breast cancer cell invasion and migration. These data also inform more efficient experimental designs for our planned in vivo studies. Full article

In this paper, we analytically investigate a diatomic molecule subject to the Morse potential under the small oscillations regime, immersed in a medium with a point defect representing impurities or vacancies in an elastic system. Initially, we apply the small oscillations method to the Morse potential to obtain an analogue to the harmonic potential, and then we solve the generalized Schrödinger equation considering the geometric effects of the defect. The solutions obtained for the bound states reveal that the energy levels and the radial stability point of the molecule are modified by the presence of the defect, depending on the parameters associated with the geometry of the medium. In a second step, we analyze the thermodynamic properties of the system in contact with a thermal reservoir at finite temperature. We derive analytical expressions for the internal energy, Helmholtz free energy, entropy, and specific heat, showing that all these quantities are influenced by the presence of the point defect. The results demonstrate how structural defects alter the quantum and thermodynamic behavior of confined molecules, contributing to the understanding of systems in non-trivial elastic media. Full article

Arginine plays a critical role in biomolecular interactions due to its guanidinium side chain, which enables multivalent electrostatic and hydrogen bonding contacts. In this study, atomistic molecular dynamics simulations were conducted across a broad concentration range (26–605 mM) to investigate the thermodynamic and structural features of arginine self-assembly in aqueous solution. Key observables—including hydrogen bond count, radius of gyration, contact number, and isobaric heat capacity—were analyzed to characterize emergent behavior. A three-regime aggregation pattern (dilute, cooperative, and saturated) was identified and quantitatively modeled using the Hill equation, revealing a non-linear transition in clustering behavior. Spatial analyses were supplemented with trajectory-based clustering and radial distribution functions. The heat capacity peak observed near 360 mM was interpreted as a thermodynamic signature of hydration rearrangement. Trajectory analyses utilized both GROMACS tools and the MDAnalysis library. While force field limitations and single-replica sampling are acknowledged, the results offer mechanistic insight into how arginine concentration modulates molecular organization—informing the understanding of biomolecular condensates, protein–nucleic acid complexes, and the design of functional supramolecular systems. The findings are in strong agreement with experimental observations from small-angle X-ray scattering and differential scanning calorimetry. Overall, this work establishes a cohesive framework for understanding amino acid condensation and reveals arginine’s concentration-dependent behavior as a model for weak, reversible molecular association. Full article

Heat capacity is one of the most important thermodynamic quantities in protein biochemistry. Upon the binding of small molecules, a change in the heat capacity of proteins is generally observed, and this is often used in drug discovery. However, few computational works dedicated to the study of these phenomena are available in the literature. Here, a simple computational method for determining the change in heat capacity upon the binding of small ligands has been evaluated. The method is based on the accurate calibration of the solvent’s thermal properties in the simulation conditions used in order to simply subtract its contribution to calculate the variations in the heat capacity of the system of interest. Using HIV protease as a model system, for which numerous experimental thermodynamic data are available, estimates of the change in heat capacity upon binding were obtained, which were similar to those observed experimentally. Furthermore, the predicted variations in heat capacity appear to be able to discriminate between molecules that behave as effective inhibitors of the enzyme and molecules that are able to bind the enzyme but not inhibit it. The results obtained suggest that this computational approach could be a useful aid in the in silico screening of new ligands for targets of interest. Full article

Sometimes, limits can be singular, implying that they take on different values depending on the order of arithmetic operations. In other words, the limit map lacks commutativity. While all such limits are mathematically valid, only one can be the physical limit. The change of measure for Brownian processes illustrates this phenomenon. A substantial body of elegant mathematics centered around continuous-time Brownian processes has been embraced by the physics community to investigate the nonequilibrium and equilibrium thermodynamics of systems composed of atoms and molecules. In this paper, we derive the continuous-time limit of discrete-time Brownian dynamics, specifically focusing on the change of measure. We demonstrate that this result yields the physical limit that differs from the commonly used expression. Consequently, the concepts of “the most probable path”, “minimum thermodynamic action”, and “the small-noise limit” are unphysical mathematical artifacts. Full article

Recent observations suggest that General Relativity (GR) faces challenges in fully explaining phenomena in regimes of strong gravitational fields. A promising alternative is the $f\left(R\right)$ theory of gravity, where R denotes the Ricci scalar. This modified theory aims to address the limitations observed in standard GR. In this study, we derive a black hole (BH) solution without introducing nonlinear electromagnetic fields or imposing specific constraints on R or the functional form of $f\left(R\right)$ gravity. The BH solution obtained here is different from the classical Schwarzschild solution in GR and, under certain conditions, reduces to the Schwarzschild (A)dS solution. This BH is characterized by the gravitational mass of the system and an additional parameter, which distinguishes it from GR BHs, particularly in the asymptotic regime. We show that the curvature invariants of this solution remain well defined at both small and large values of r. Furthermore, we analyze their thermodynamic properties, demonstrating consistency with established principles such as Hawking radiation, entropy, and quasi-local energy. This analysis supports their viability as alternative models to classical GR BHs. Full article

Thermal energy storage technologies are essential for balancing energy demand and supply. There are three main types: sensible heat, latent heat, and thermochemical energy storage. Among them, thermochemical energy storage offers the highest energy density (1–3 GJ/m³) and long-term storage capability. Salt hydrates have attracted attention as energy storage materials due to their low cost, wide availability, and operating temperatures being well-suited for residential and low-temperature applications. This review focuses on the use of salt hydrates in sorption-based thermochemical energy storage systems. It summarizes the current state of knowledge, including screening studies of various salt hydrates, their thermodynamic and operational limitations, advantages, and performance in composite materials. This review also covers recent projects and common reactor designs used in TCES applications. Based on the literature analysis, the most promising salt hydrates for sorption-based TCES systems include SrCl₂, SrBr₂, K₂CO₃, MgSO₄, MgCl₂, and CaCl₂. Despite the high theoretical energy density of many salt hydrates, future work should focus on experimental studies in large-scale reactor systems to better evaluate the practical discharge behavior of the energy storage system beyond theoretical hydration enthalpies or small-scale thermal analyses. Full article

In order to reduce the content of harmful impurity sulfur elements in steel to meet the quality requirements of high value-added steel, efficient desulfurization of RH vacuum degassing is essential. Based on the simplex lattice composition design method, the effects of typical compositions on liquidus temperature, sulfur capacity, melting temperature, the effects of typical compositions on liquidus temperature, sulfur capacity, melting temperature, viscosity, and desulfurization rate of CaO-CaF₂- and CaO-Al₂O₃-SiO₂-based desulfurizers were studied by thermodynamic calculation, the melting temperature test, and the slag–steel contact experiment. The results show that in CaO-CaF₂- and CaO-Al₂O₃-SiO₂-based desulfurizers, the changes in CaF₂, MgO, and Al₂O₃ contents has little effect on the equilibrium S content of molten steel at lower SiO₂ contents, whereas, at higher SiO₂ contents, the equilibrium S content of the molten steel is greatly increased when the CaF₂, MgO, and Al₂O₃ content is greater than a certain value. Meanwhile, the increase in CaF₂ and MgO content reduces the high-temperature viscosity and breaking temperature (corresponding to the turning point on the viscosity–temperature curve) to varying degrees, which results in a better slag fluidity and is favorable to the prevention of crusting. With the increase in Al₂O₃ and SiO₂ content, the breaking temperature of the CaO-CaF₂-based desulfurizer is significantly reduced, which is beneficial to preventing crust. However, when the breaking temperature of CaO-Al₂O₃-SiO₂-based desulfurizer increases, part of the slag system has solidified at 1400 °C, which is easy to lead to slag crust when the temperature drops. Comprehensively, for the CaO-CaF₂-based desulfurizer, CaO = 60 wt%, CaF₂ = 30 wt%, SiO₂ = 0–5 wt%, and add a small amount of Al₂O₃ and MgO, its desulfurization effect is significant. For the CaO-Al₂O₃-SiO₂-based desulfurizer, CaO = 39–57 wt%, Al₂O₃ = 20–35 wt%, SiO₂ = 10–15 wt%, MgO = 4 wt%, CaF₂ = 4–8 wt%, its desulfurization effect meets the demand, and it can reduce equipment erosion and environmental pollution. Full article

A thorough understanding of the chemistry involved in reinjecting heat-depleted geothermal water into poorly consolidated sandstone is vital for the effective design of treatments targeting subsurface rock formations. The intricate chemical interactions occurring within sandstone systems can result in the dissolution of certain minerals and the subsequent precipitation of others, which may significantly contribute to damage within the formation. This process can alter the physical properties of the rock, potentially leading to reduced permeability and other challenges in resource extraction. Thus, it is imperative to monitor not only the concentration of various chemical species present in the geothermal water and sandstone, but also the spatial distribution of these geochemical reactions. By doing so, we can better predict and mitigate their potential adverse effects on rock formations, ensuring the long-term success and efficiency of geothermal energy extraction and other subsurface activities. In this study, we conducted laboratory experiments using both model and natural formation waters, as well as rock samples, to investigate water–rock interactions in a sandstone reservoir in the Szentes area of Hungary. Geochemical models were run with two different thermodynamic databases to simulate laboratory experiments, predict the effects of heat-depleted geothermal water reinjection into the reservoir, and assess predictions of different geochemical databases. Our study shows that calcite dissolves while quartz, kaolinite, and dolomite form. Other mineral reactions, however, remain less certain. The PHREEQC database indicates chlorite dissolution along with the formation of small amounts of feldspars and hematite, whereas the Thermoddem database predicts montmorillonite dissolution and chlorite precipitation. The reservoir porosity and permeability are expected to change over time as a result of mineral reactions. Modeling results, however, indicate negligible porosity changes as the reservoir reaches equilibrium state. The general concept proposed here, which focuses on the geochemical properties of the reinjected water and reservoir, provides a framework for detailed analysis of the geothermal system—a critical step for ensuring sustainable geothermal operations. Full article

Background/Objectives: Raynaud’s phenomenon (RP) is characterized by an exaggerated vasoconstrictive response of small blood vessels in the fingers and toes to cold or stress. Oral therapy with tadalafil (TDL), a phosphodiesterase-5 inhibitor, is limited by systemic side effects and reduced patient compliance. This study aimed to develop and evaluate a TDL-loaded nanoemulgel for transdermal delivery as a non-invasive treatment alternative for cold-induced vasoconstriction. Methods: TDL-loaded nanoemulsions were prepared using the aqueous titration method with cinnamon oil as the oil phase and Cremophor RH40 and Transcutol as the surfactant–cosurfactant system. The optimized nanoemulsion was incorporated into a carbopol-based gel to form a nanoemulgel. The formulation was characterized for droplet size, morphology, thermodynamic stability, rheological properties, in vitro drug release, skin permeation, and pharmacokinetic behavior. Infrared thermography was employed to assess in vivo efficacy in cold-induced vasoconstriction models. Results: The optimized TDL nanoemulsion exhibited a spherical morphology, a nanoscale droplet size, and an enhanced transdermal flux. The resulting nanoemulgel displayed suitable physicochemical and rheological properties for topical application, a short lag time (0.7 h), and a high permeability coefficient (Kp = 3.59 × 10⁻² cm/h). Thermal imaging showed significant vasodilation comparable to standard 0.2% nitroglycerin ointment. Pharmacokinetic studies indicated improved transdermal absorption with a higher C_max (2.13 µg/mL), a prolonged half-life (t_1/2 = 16.12 h), and an increased AUC_0–24 compared to an oral nanosuspension (p < 0.001). Conclusions: The developed TDL nanoemulgel demonstrated effective transdermal delivery and significant potential as a patient-friendly therapeutic approach for Raynaud’s phenomenon, offering an alternative to conventional oral therapy. Full article

This research aims to understand the experimental results on the high selectivity of Pb²⁺ removal over Cd²⁺ in natural and dealuminated rich-clinoptilolite. For this purpose, we have considered the results of experimental and Density Functional Theory (DFT)-based simulated annealing (SA) on sorption of Pb²⁺ and Cd²⁺ from aqueous solution. The dealumination process of natural clinoptilolite (Nat-CLI) was done by H₂SO₄ solutions at different concentrations (0.1–1.0 M). The results show that the maximum sorption capacity (q_,max) of Pb²⁺ and Cd²⁺ varied from 224.554 × 10⁻³ to 53.827 × 10⁻³ meq/g, and between 39.044 × 10⁻³ to 20.529 × 10⁻³ meq/g, respectively, when the values of Si/Al ratio change from 4.36 to 9.50. From a theoretical point of view, the global minimum energies of natural and dealuminated clinoptilolites before and after sorption of Pb²⁺ and Cd²⁺ were calculated by an SA method, where heating-cooling cycles were modeled by ab initio Molecular Dynamics followed by energy minimization. The theoretical results confirmed that for all Si/Al ratios, the sorption of Pb²⁺ and Cd²⁺ takes place, and for dealuminated systems, the exchange energy outcomes are more favorable for the Pb²⁺ cations. Since such energy differences are very small, it is not explained from a thermodynamic point of view. On the other hand, it could be understood from a kinetic perspective. In this way, we set that the atomic structural properties of the zeolite modify the first hydration coordination sphere of metal cations. Full article

Industrial hemp (Cannabis sativa L.) was investigated as a sustainable biosorbent for removing Congo Red (CR) and Remazol Brilliant Blue R (RBBR) from wastewater. The unmodified hemp biosorbent exhibited moderate but practically relevant sorption capacities (4.47 mg/g for CR; 2.44 mg/g for RBBR), outperforming several agricultural waste materials. Kinetic studies revealed rapid uptake, with CR following pseudo-first-order kinetics (t₁/₂ < 15 min) and RBBR fitting the Elovich model, indicating heterogeneous surface interactions. Equilibrium data showed CR adsorption was best described by the Temkin isotherm (R² = 0.983), while RBBR followed the Langmuir model (R² = 0.998), reflecting their distinct binding mechanisms. Thermodynamic analysis confirmed spontaneous (ΔG° < 0), exothermic (ΔH° ≈ −2 kJ/mol), and entropy-driven processes for both dyes. Molecular docking elucidated the structural basis for performance differences: CR’s stronger binding (−7.5 kcal/mol) involved weak noncovalent interaction arising from partial overlap between the π-electron cloud of an aromatic ring and σ-bonds C-C or C-H (π-σ stacking) and hydrogen bonds with cellulose, whereas RBBR’s weaker affinity (−5.4 kcal/mol) relied on weak intermolecular interaction between a hydrogen atom (from a C-H bond) and the π-electron system of an aromatic ring (C-H∙∙∙π interactions). This work establishes industrial hemp as an eco-friendly alternative for dye removal, combining renewable sourcing with multi-mechanism adsorption capabilities suitable for small-scale water treatment applications. Full article

The LNG maritime industry started to anticipate offshore LNG production in tandem with increasing demand for FLNG platforms as offshore gas resources were developed further. The rapid expansion of FLNG deployment demands equipment and procedures that handle challenges associated with weight and space constraints. The chemical composition of LNG will result in slightly fewer CO₂ emissions. While not significant, another crucial aspect is that LNG predominantly comprises methane, which is acknowledged as a greenhouse gas and is more harmful than CO₂. This requires investigation into clean energy fuel supply for power generation systems, carbon emissions from the process, and thermodynamic analysis and optimisation. Focus on supplying fuel for FLNG power generation to reduce the essential management of boil-off fuel gas, which can be researched on the direct reforming method of hydrogen as a marine fuel gas to support the power generation system. The principal reason for choosing hydrogen over other energy sources is its exceptional energy-to-mass ratio (H/C ratio). The most effective method for hydrogen production is the methane reforming process, recognised for generating significant quantities of hydrogen. To optimise the small-scale plant with a carbon capture system (CCS) as integrated into the reforming process to produce blue hydrogen fuel with zero carbon emissions, this research selection focuses on two alternative processes: steam methane reforming (SMR) and autothermal reforming (ATR). Furthermore, the research article will contribute to other floating production platforms, such as FPSOs and FSRUs, and will be committed to clean energy policies that mandate the support of green alternatives in substitution of hydrocarbon fuel utilisation. Full article

The thermodynamic equilibrium of the gas-phase system in lead smelting flue gas was studied using FactSage 8.2 software, and the effects of temperature, the main components of the gas phase, and other factors on the SO₃ content in the equilibrated flue gas were investigated. In addition, experimental research was conducted on a solid-phase catalysis experimental platform to investigate the effect of lead smelting ash on SO₂ catalytic oxidation. The results show that temperature and initial O₂ content in flue gas have a significant impact on the equilibrium concentration of SO₃, while the initial SO₂ content in flue gas has a relatively small impact on the equilibrium concentration of SO₃; the fly ash from the lead smelting flue promotes the conversion of SO₂ to SO₃ in the flue gas. SO₃-suppression experiments show that PbS can adequately inhibit SO₃ formation in a simulated flue gas environment, and the content of SO₃ after adding PbS under different oxygen contents and SO₂ atmospheres does not exceed 0.6%. Through the method of thermodynamic simulation and experimental verification, this study reveals the catalytic oxidation mechanism of SO₂ in lead dust and proposes the use of PbS as an in situ SO₃ inhibitor. Full article