Search Results (2,726)

This article investigates the mechanism of self-organized DNA criticality with open states, which plays a key role in the regulation of gene expression and consequently in cell fate determination. Based on a mechanobiological model developed using methods of statistical physics and thermodynamics, we demonstrate that the collective behavior of DNA open-state ensembles governs transitions between bistable, metastable, and critical genomic states. These states correspond to different gene expression scenarios involved in cell fate determination. Through simulation results, we introduce the concept of a criticality cascade, linking the dynamics of the DNA molecule structural parameter χ with global changes in cellular processes. The findings align with experimental data and offer new perspectives for studying genome regulation mechanisms, including pathological conditions such as cancer. Full article

The study aims to promote environmental restoration by shedding light on the potential use of moringa waste as an inexpensive, eco-friendly adsorbent for treating wastewater contaminated with Chromium (VI). FTIR was used to characterise the surface functional groups of moringa waste. The one-factor-at-a-time method was used to study the initial concentration in milligrams per litre, contact time in minutes, temperature in degrees Celsius, pH, and adsorbent dosage in milligrams per litre. The output was the removal percentage. Furthermore, adsorption isotherms, kinetics, and thermodynamic models were applied to understand the process behaviour. FTIR examination revealed the moringa waste structure’s stability and aromaticity, confirmed by peaks located around 1596 cm⁻¹ and the stretching of the hydroxyl group around 3321 cm⁻¹, which are important for enhancing Cr (VI) adsorption due to their capability to establish strong bonds with metal ions. Aromatic rings contribute to a large surface area and porosity and are stable; this is important for adsorption applications. At 60 min of contact time with a pH of 6 and 0.5 g of adsorbent dosage at 45 °C for a concentration of 100 mg/L, the highest removal percentage was found to be 77.03%. Adsorption data values indicated a good fit to the Langmuir isotherm model. The thermodynamic study showed that the process is endothermic and spontaneous, hence making the application of moringa waste in wastewater treatment viable. Full article

Niosomes are nanocarriers with a bilayer structure, consisting of a polar region and a non-polar region. This unique structure allows them to encapsulate compounds with varying polarities, addressing solubility challenges in the transport and delivery of bioactive molecules. The formation of niosomes involves key structural, geometric, and thermodynamic factors influenced by the choice of surfactants and preparation methods. These factors, including the critical packing factor and the hydrophilic–lipophilic balance (HLB), play a crucial role in determining the properties of the final niosomes. Additionally, the use of Tandford’s equations allows for the calculation of geometric parameters. These factors determine the structural integrity and functional properties of niosomes, making it possible to design functional niosomes with characteristics tailored for specific applications. This ability to design niosomes with desired properties is especially valuable in biomedical fields, where precise control over drug delivery and targeting is essential. This review highlights the importance of niosome formulation and presents examples of niosomes that have been functionalized for specific applications, including anticancer treatments, immunological treatments, and their action in the central nervous system. Full article

The determination of RNA secondary structure (RSS) could help understand RNA’s functional mechanisms, guiding the design of RNA-based therapeutics, and advancing synthetic biology applications. However, traditional methods such as NMR for determining RSS are typically time-consuming and labor-intensive. As a result, the accurate prediction of RSS remains a fundamental yet unmet need in RNA research. Various deep learning (DL)-based methods achieved improved accuracy over thermodynamic-based methods. However, the over-parameterization nature of DL makes these methods prone to overfitting and thus limits their generalizability. Meanwhile, the inconsistency of RSS predictions between these methods further aggravated the crisis of generalizability. Here, we propose TrioFold to achieve enhanced generalizability of RSS prediction by integrating base-pairing clues learned from both thermodynamic- and DL-based methods by ensemble learning and convolutional block attention mechanism. TrioFold achieves higher accuracy in intra-family predictions and enhanced generalizability in inter-family and cross-RNA-types predictions. Additionally, we have developed an online webserver equipped with widely used RSS prediction algorithms and analysis tools, providing an accessible platform for the RNA research community. This study demonstrated new opportunities to improve generalizability for RSS predictions by efficient ensemble learning of base-pairing clues learned from both thermodynamic- and DL-based algorithms. Full article

The pharmaceutical contamination of water, especially by widely used drugs, presents important environmental and health concerns due to the inefficiency of conventional treatment methods. The present study proposes a sustainable solution using biochar (Bch) obtained from tomato waste, functionalized with Fe₃O₄ and MnO₂ nanoparticles, for the removal of paracetamol from aqueous solutions. The composite materials were synthesized, characterized, and evaluated under varying conditions, including pH, temperature, contact time, initial drug concentration, and adsorbent dose. The materials exhibited porous structures with wide pore size distributions. Optimal removal efficiency was achieved for 30 mg L⁻¹ paracetamol concentration, pH 2, 25 °C, 0.3 g L⁻¹ adsorbent dose, and 20 min contact time. The Freundlich isotherm provided the best fit for the adsorption data. Kinetic studies revealed that the pseudo-second-order model best described the adsorption process. Thermodynamic parameters indicated that the process was spontaneous, feasible, and exothermic. Compared with similar materials derived from agricultural waste, the tomato waste-based composites demonstrated competitive adsorption capacities. These findings suggest that Bch-HCl/MnO₂ and Bch-HCl/Fe₃O₄/MnO₂ are promising, cost-effective adsorbents for mitigating pharmaceutical pollutants in wastewater. Full article

A usual problem in chemical engineering and fuel processing is to achieve the highest possible efficiency concerning the target products. In this paper, we consider the inverse problem of chemical equilibrium and propose mathematical methods to obtain conditions under which the equilibrium state of the reacting system achieves the required characteristics. For the case of maximising the aim component yield, a new two-step algorithm is developed based on the inverse problem solution. The methods are tested using the methane reforming example. Full article

This study investigates the exergoeconomic performance of a milk pasteurization system powered by geothermal energy, operating across geothermal source temperatures (GSTs) ranging from 80 °C to 110 °C. The system uses geothermal heat as its primary energy source, while the cooling process is supported by a vapor compression refrigeration cycle driven by electricity generated through an Organic Rankine Cycle (ORC). The analysis was carried out in three stages: determining system parameters for each GST level, conducting detailed energy and exergy analyses, and performing an exergoeconomic evaluation using the specific exergy costing (SPECO) method. The results show that both energy and exergy efficiencies decline as GST increases. Energy efficiency varies between 88.30% and 78.53%, while exergy efficiency ranges from 72.86% to 58.02%. In parallel, unit-specific manufacturing costs increase with higher GST. Electricity production costs range from 610 to 900 USD·MWh⁻¹, and the cost of pasteurized milk varies between 3.76 and 6.53 USD·ton⁻¹. These findings offer practical insights into how geothermal source temperature affects the thermodynamic and economic performance of such systems, contributing to the broader understanding of sustainable dairy processing technologies. Full article

Scandium(III) (Sc(III)) is the smallest among the trivalent ions in Group 3, which includes yttrium(III) and lanthanides (III) with a hydration number of 8 and 8–9, respectively. The hydration number of Sc(III) in aqueous solutions reported so far varies from six to ten and remains an open question. In general, applying pressure and temperature to aqueous solutions perturbs the water structure and ion solvation, providing insight into the nature of ion solvation. In the present study, we perform neutron scattering measurements of a 1 m (mol/kg) ScCl₃ aqueous solution in D₂O (hereafter H is used to symbolize the hydrogen atom instead of D) under the thermodynamic conditions from 0.1 MPa/298 K to 4 GPa/523 K. Using the empirical potential structure refinement (EPSR) method, the neutron scattering data are analyzed to extract the site–site pair distribution functions, coordination number distributions, angle distributions, and spatial density functions (3D structure). A predominant Sc(III) species is [Sc(OH₂)₇]³⁺ with a distorted pentagonal bipyramidal geometry together with appreciable amounts of contact ion pair species [ScCl_n(OH₂)_(6−n)]⁽³⁻ⁿ⁾⁺ (n = 1–3) and [Sc(OH₂)₈]³⁺ with mean Sc–Cl and Sc–OH₂ distances of 2.42 and 2.11 Å, respectively. An aqua chloride ion is surrounded on average by 7.8 and 10.9 water molecules with a Cl–H₂O distance of 3.10 Å at 0.1 MPa/298 K and 4 GPa/523 K, respectively. Applying GPa pressure transforms the tetrahedral network structure of water under ambient conditions to a dense, randomly packed structure with a mean coordination number of 12.6, resulting in an increase in the first-neighbor distance from 2.77 to 2.89 Å. The hydrogen bonds between water molecules remain linear but are largely distorted at high temperatures and high pressures. The present results provide a hint for understanding the underlying mechanism of high-pressure and temperature coordination chemistry and in applied fields, such as processes in geochemistry of the Earth’s upper mantle and pressure-induced protein denaturation. Full article

Due to the high cost of hydrogen utilization and the uncertainties in renewable energy generation and load demand, significant challenges are posed for the operation optimization of hydrogen-containing integrated energy systems (IESs). In this study, a robust operational model for an electric–heat–gas IES (EHG-IES) is proposed, considering the hydrogen energy system heat recovery (HESHR) and multiple uncertainties. Firstly, a heat recovery model for the hydrogen system is established based on thermodynamic equations and reaction principles; secondly, through the constructed adjustable robust optimization (ARO) model, the optimal solution of the system under the worst-case scenario is obtained; lastly, the original problem is decomposed based on the column and constraint generation method and strong duality theory, resulting in the formulation of a master problem and subproblem with mixed-integer linear characteristics. These problems are solved through alternating iterations, ultimately obtaining the corresponding optimal scheduling scheme. The simulation results demonstrate that our model and method can effectively reduce the operation and maintenance costs of HESHR-EHG-IES while being resilient to uncertainties on both the supply and demand sides. In summary, this study provides a novel approach for the diversified utilization and flexible operation of energy in HESHR-EHG-IES, contributing to the safe, controllable, and economically efficient development of the energy market. It holds significant value for engineering practice. Full article

Global warming, anthropogenic pressure, and urban expansion at the expense of green spaces are leading to an increase in the incidence of urban heat islands, creating discomfort and health issue for citizens. This present research aimed at quantifying the impact of nature-based solutions to support decision-making processes in sustainable energy action plans. A simple method is provided, linking applied thermodynamics to physics-informed modeling of urban built-up and green areas, high-resolution climate models at urban scale, greenery modeling, spatial georeferencing techniques for energy, and entropy exchanges evaluation in urban built-up areas, with and without vegetation. This allows the outdoor climate conditions and thermo-hygrometric well-being to improve, reducing the workload of cooling plant-systems in buildings and entropy flux to the environment. The finalization and post-processing of obtained results allows the definition of entropy footprints. The main findings show a decrease in greenery’s contribution for different scenarios, referring to a different climatological dataset, but an increase in entropy that becomes higher for the scenario with higher emissions. The comparison between the entropy footprint values for different urban zones can be a useful support to public administrations, stakeholders, and local governments for planning proactive resilient cities and anthropogenic impact reduction and climate change mitigation. Full article

γ-TiAl alloy is a lightweight high-temperature structural material, featuring low density, excellent high-temperature strength, creep resistance, etc. It is a key material in the aerospace field. However, the essential defects of γ-TiAl alloys, such as poor room-temperature plasticity and low fracture toughness, have become the biggest obstacles to their practical application. Therefore, in this paper, the physical mechanism of modification of the mechanical properties and electronic structure of γ-TiAl alloys by doping with Sc, V, and Si was investigated by using the first-principles pseudopotential plane wave method. This paper specifically calculates the geometric structure, phonon spectrum, mechanical properties, electron density of states, Mulliken population analysis, and differential charge density of γ-TiAl alloys before and after doping. The results show that after doping, the structural parameters of γ-TiAl have changed significantly, and the doping models all have thermodynamic stability. The B, G, and E values of the doped system are, respectively, within the range of 94–112, 57–69, and 143–170 GPa, indicating that the material’s ability to resist compressive deformation is weakened. Moreover, the B/G values change from 1.5287 to 1.6350, 1.7279, and 1.6327, respectively, and a transformation from brittleness to plasticity occurs. However, it is still lower than the critical value of 1.75, indicating that the doped γ-TiAl alloy material retains its high-strength characteristics while also exhibiting a certain degree of toughness. The total elastic anisotropy index of the doped system increases, and the degree of anisotropy of mechanical behavior significantly increases. The total electron density of states diagram indicates that γ-TiAl alloys possess conductive properties. The covalent interactions between doped atoms and adjacent atoms have been weakened to varying degrees, which is manifested as a significant change in the charge distribution around each atom. The above results indicate that the doping of Sc, V, and Si can effectively tune the mechanical properties and electronic structure of γ-TiAl alloys. Full article

The Fermi condensation flows in the sine-Gordon–Thirring model with two impurities coupling are investigated in this paper; these matter flows can be induced by the Ricci flow perturbation in the two-dimensional string $\sigma$ model. The Ricci flow perturbation equations are derived according to the Gauss–Codazzi equations, and the two-loop asymptotic perturbation solution of the cigar soliton is reduced by using a small parameter expansion method. Moreover, the thermodynamic quantities on the cigar soliton background are obtained by using the variational functional integrals method. Subsequently, the Fermi condensation flows varying with the momentum scale $\lambda$ are analyzed and discussed. We find that the energy density, the correlation function, and the condensation fluctuations will decrease, but the entropy will increase monotonically. The Fermi condensed matter can maintain thermodynamic stability under the Ricci flow perturbation. Full article

The thermo-hydrological (TH) coupling model constitutes the foundational framework for investigating the temperature distribution of surrounding rock in cold region tunnels. In this study, a fully coupled TH model is proposed that takes into account multiple physical phenomena during the freezing process of surrounding rock. Firstly, the model was established based on thermodynamics, seepage theory, and ice–water phase change theory, which accounted for unfrozen water, latent heat of phase change, ice impedance, and convective heat transfer. The model was successfully verified by comparing its results to field data. Next, the sensitivity of surrounding rock temperature to environmental, thermodynamic, seepage, and coupling parameters in the fully coupled TH model was systematically studied using a numerical analysis method. The results show that the annual temperature amplitude and thermal conductivity represent the main factors affecting the surrounding rock temperature at a radial depth of 0 m, while the initial temperature and porosity are the key factors at a radial depth of 5 m. Permeability has the least influence on the surrounding rock temperature, but the temperature field will experience sudden changes if its value exceeds its value exceeds 1 × 10⁻¹² m². Finally, using the proposed numerical model, the thickness of insulation layer was simulated, and the degree of influence of the parameters on the thickness of insulation layer was analyzed. This study reveals that the annual temperature amplitude has the greatest influence on the calculation of insulation layer thickness, with its normalized sensitivity factor being approximately 50%. These findings not only expand the methodology for exploring the laws of TH coupling but also provide a theoretical foundation for improving the parameter calibration efficiency and calculation accuracy of the fully coupled TH model, and they have significant reference value. Full article

Metal hydrides are emerging hydrogen-storage materials that have attracted much attention for their stability and practicality. The novel magnesium-based metal hydride Mg₂CsH₉ was investigated using the CALYPSO software (version 7.0). First-principles predictive methods were then employed to investigate the structural, mechanical, electronic, optical, and hydrogen-storage properties of Mg₂CsH₉ and its alkali metal substitution structure Mg₂RbH₉. The negative formation energy, compliance with the Born stability criterion, and absence of imaginary modes in the phonon spectrum collectively confirm the thermodynamic, mechanical, and dynamic stability of Mg₂XH₉ (X = Cs, Rb), fulfilling the basic criteria for practical hydrogen-storage applications. Mg₂RbH₉ is particularly outstanding in terms of its hydrogen-storage capacity, with a gravimetric capacity of 6.34 wt% and a volumetric capacity as high as 92.70 g H₂/L, surpassing many conventional materials. The pronounced anisotropic characteristics of both compounds further enhance their practicality and adaptability to complex working conditions. An analysis of Poisson’s ratio revealed that the chemical bonding in both compounds is predominantly ionic. The details of the band structures and density of states indicate that Mg₂CsH₉ and Mg₂RbH₉ are semiconductors. Their optical properties confirm them as being high-refractive-index materials. Full article

The thermal insulation performance of liquid hydrogen (LH₂) storage tanks is critical for long-distance transportation. The active cooled shield (ACS) technologies, such as the liquid nitrogen cooled shield (LNCS) and the vapor hydrogen cooled shield (VHVCS) are important thermal insulation methods. Many researchers installed the VHVCS inside the multilayer insulation (MLI) and obtained the optimal position. However, the MLI layer is often thinner than the vacuum interlayer between the inner and outer tanks, and there is a large vacuum interlayer between the outermost side of MLI and the inner wall of the outer tank. It is unknown whether the insulation performance can be improved if we install ACS in the mentioned vacuum interlayer and separate a portion of the MLI to be installed on the outer surface of ACS. In this configuration, the number of inner MLI (IMLI) layers and the ACS position are interdependent, a coupling that has not been thoroughly investigated. Therefore, thermodynamic models for MLI, MLI-LNCS, and MLI-VHVCS schemes were developed based on the Layer-by-Layer method. By applying Robin boundary conditions, the temperature distribution and heat leakage of the MLI scheme were predicted. Considering the coupled effects of IMLI layer count and ACS position, a co-optimization strategy was adopted, based on an alternating iterative search algorithm. The results indicate that for the MLI-LNCS scheme, the optimal number of IMLI layers and LNCS position are 36 layers and 49%, respectively. For the MLI-VHVCS scheme, the optimal values are 21 layers and 39%, respectively. Compared to conventional MLI, the MLI-LNCS scheme achieves an 88.09% reduction in heat leakage. However, this improvement involves increased system complexity and higher operational costs from LN₂ circulation. In contrast, the MLI-VHVCS scheme achieves a 62.74% reduction in heat leakage, demonstrating that using sensible heat from cryogenic vapor can significantly improve the thermal insulation performance of LH₂ storage tanks. The work of this paper provides a reference for the design and optimization of the insulation scheme of LH₂ storage tanks. Full article