Thermodynamic Perspective Research Articles

Boosting Photocatalytic Water Splitting of Polymeric C60 by Reduced Dimensionality from Two-Dimensional Monolayer to One-Dimensional Chain.

The recent synthesis of monolayer fullerene networks (Hou, L., et al. Nature 2022, 606, 507) provides new opportunities for photovoltaics and photocatalysis because of their versatile crystal structures for further tailoring of electronic, optical, and chemical function. To shed light on the structural aspects of the photocatalytic water splitting performance of fullerene nanomaterials, we compare the photocatalytic properties of individual polymeric fullerene chains and monolayer fullerene networks from first-principles calculations. We find that the photocatalytic efficiency can be further optimized by reducing the dimensionality from two-dimensional (2D) to one-dimensional (1D). The conduction band edge of the polymeric C60 chain provides an external potential for the hydrogen reduction reaction much higher than that of its monolayer counterparts over a wider range of pH values, and there are 2 times more surface active sites in the 1D chain than in the 2D networks from a thermodynamic perspective. These observations identify the 1D fullerene polymer as a more promising candidate as a photocatalyst for the hydrogen evolution reaction in comparison to monolayer fullerene networks.

Agglomeration inhibition mechanism of SiO2 in the Ca(OH)2/CaO thermochemical heat storage process: A reactive molecular dynamics study

As a promising thermochemical heat storage material, the Ca(OH)2/CaO can be agglomerated after repeated heat storage cycles, which will affect its performance severely. Experimental evidence indicated that the dopant of SiO2 particles alleviated the agglomeration phenomenon of Ca(OH)2/CaO. However, the mechanisms have not been clarified in theory, including the agglomeration of Ca(OH)2/CaO and the agglomeration inhibition of SiO2. Investigating these mechanisms is important for the broad application of Ca(OH)2/CaO thermochemical heat storage technology. In this paper, reactive molecular dynamics is employed to simulate and quantify the agglomeration of Ca(OH)2 and the inhibition by SiO2 during the heat storage process. Then, the agglomeration phenomena under the two processes are quantitatively described. The mechanisms are analyzed by using the parameters of kinetics and thermodynamics. From the phenomenological analysis, smaller size changes, larger mass center distances, and smaller atomic displacements indicate that SiO2 doping reduces the tendency of nanoparticles to agglomerate into a larger cluster. From the kinetic perspective, the diffusion of pure Ca(OH)2 clusters conforms to viscous flow, while the diffusion of the SiO2-doped clusters is close to surface diffusion. The dopant of SiO2 increases the activation energy of the diffusion process, which would increase the atomic mobility resistance and thus inhibit the agglomeration. From the thermodynamic perspective, cluster agglomeration is mainly caused by the work done by van der Waals forces, which leads to a decrease in potential energy, especially surface potential energy. By doping SiO2, the interatomic van der Waals forces are increased, which lowers the stable potential energy surface of the clusters, thereby obtaining a more stable structure to inhibit agglomeration.

Development of High-Entropy Alloys as Bond Coats: A Thermodynamic and Kinetic Perspective

Development of High-Entropy Alloys as Bond Coats: A Thermodynamic and Kinetic Perspective

Thermodynamic analysis of molten salt-based single-tank thermal energy storage system with heat transfer enhanced by gas injection

In this study, the feasibility of gas injection for enhancing heat transfer in a molten salt thermal storage system was experimentally investigated. The convective heat transfer coefficient induced by the gas injection was quantitatively measured. A predictive model was developed to estimate the heat transfer coefficient with respect to the gas injection rate. A comparative analysis between gas-injection and non-injection cases was also performed from a thermodynamic perspective to verify the feasibility of the method. The heat transfer coefficient was within the range of 359–1283 W/m2-K, depending on the gas injection rate. The developed model estimated the measured values within an average absolute error of 2%. From the comparative analysis, the gas injection method improved thermal efficiency from 86.3% to 95.1%. The energy loss induced by the gas injection was within the range of 0.2%–1.1% of the total stored energy. The gas injection also shortened the energy discharge time by 32%–41% owing to the heat transfer enhancement. The proposed method also improved the system performance by enhancing the exergy transfer rate from the salt to the water. These results indicate that a gas injection method is a potential candidate for improving molten salt thermal storage systems.

Theoretical insight into the aqueous transformation mechanism of terbutaline using O3 and •OH of advanced oxidation processes

Terbutaline (TBL, an β-agonists pharmaceuticals) is one of the pharmaceuticals and personal care products (PPCPs), which has caused many environmental concerns due to its eco-toxicological effects in aquatic environment. In this research, density functional theory (DFT) and quantitative structure–activity relationships (QSARs) toxicity methods were performed to systematically elucidate the transformation mechanisms and ecological risk of TBL degraded by •OH and O3. By analyzing the structure and electronic properties of TBL, the •OH-addition, H-abstraction, single electron transfer and 1, 3-cycloaddition ozonation degradation pathways were mainly investigated. The lowest energy barriers of •OH and O3 initiated reactions in the degradation process were 7.33 and 18.49 kcal mol−1 respectively, which indicated that the •OH degradation process was more likely to occur than O3 induced reactions from a thermodynamic perspective. The kinetic rate constants of O3 and •OH at 298 K were calculated as 7.58 M−1 s−1 and 1.02 × 109 M−1 s−1, respectively. Furthermore, the subsequent intermediates could further transform into hydroxylation substitutes, glyoxylic acid and ketoaldehyde by-products. Based on toxicity assessments, parent reactant TBL can exhibit harmful acute and chronic toxicity to daphnid (identified by LC50 33.2 mg L−1 and ChV 2.34 mg L−1). The toxicity of most of the degradation products was reduced to harmless level compared with the parent reactant TBL. This work provided a molecular level understanding for evaluating the contribution of O3 and •OH to the removal of TBL from wastewater by theoretical calculations.

Nanoconfinement boosts affinity of hydrated zirconium oxides to arsenate: Surface complexation modeling study

Nanoscale hydrated zirconium oxide (HZO) holds great potential in groundwater purification due to its ability to form inner-sphere coordination with arsenate. Despite being frequently used, especially as encapsulations in host materials for practical application in water treatment, the adsorption mechanisms of solutes on HZO are not appropriately explored, in particular for arsenate adsorption. In this study, we investigated the Zr–As coordination configuration and identified the most credible Zr–As configuration using surface complexation modeling (SCM), XPS and FT-IR analysis. The corresponding intrinsic coordination constants (Kintr) values was calculated by SCM, and the nanoconfinement effects were distinguished by comparing bare HZO with the HZO nanoparticles (NPs) encapsulated inside the strongly basic anion exchanger D201. Potentiometric titration suggests that the surface Zirconium hydroxyl groups (≡ZrOH) mainly exist in protonated form (≡ZrOH2+). Batch adsorption experiments demonstrate that the D201 hosts could adsorb As(V) through ion exchange by the quaternary ammonium groups under the low ionic strength (≤0.01 M NaNO3) and at pH > 6. The nanocomposite (HZO@D201) exhibits a higher adsorption capacity in a wide range of pH (3-10) and ionic strength (0.001–0.1 M NaNO3) than bare HZO. SCM simulations reveal that the coordination configuration of diprotonated monodentate mononuclear (MM-H2) dominates at pH 3–6, while deprotonated bidentate binuclear (BB–H0) dominates at pH > 7. For each configuration, the intrinsic coordination constants (Kintr) of HZO@D201 (10−0.66 and 10−16.10, respectively) are significantly higher than those of bare HZO (10−12.24 and 10−44.42, respectively), indicating a superior chemical bonding affinity caused by nanoconfinement. The obtained Kintr values are used to predict arsenate adsorption isotherms in pH 3 and 9, and the results align with the SCM simulation outcomes. This study may offer a feasible method for investigating the nanoconfinement effect of emerging nanocomposite adsorbents from a thermodynamic perspective, and provide reference coordination equilibrium constants of HZO for research and practical application.

A Thermodynamic Perspective of Cancer Cells' Volume/Area Expansion Ratio.

The constructal law is used to improve the analysis of the resonant heat transfer in cancer cells. The result highlights the fundamental role of the volume/area ratio and its role in cancer growth and invasion. Cancer cells seek to increase their surface area to facilitate heat dissipation; as such, the tumour expansion ratio declines as malignant cells start to migrate and the cancer expands locally and systemically. Consequently, we deduce that effective anticancer therapy should be based on the control of some ion transport phenomena in an effort to increase the volume/area ratio. This emphasises restricting the local and systemic spatial expansion of the tumour system and thus gives further credence to the superior role of novel anti-migratory and anti-invasive treatment strategies over conventional anti-proliferative options only.

Effect of laser power, speed and offset on the welding performance of 304 SS/Al2O3 ceramics

In this study, 304 SS/Al2O3 ceramic structural parts were successfully prepared by laser heat source biasing using AgCuTi as filler. The method removes residual thermal stresses by retaining unfused 304 SS (stainless steels), provides protection to the Al2O3 ceramics, and connects the two sides of the substrate using the wettability of the AgCuTi filler. Based on the 304 SS/Al2O3 connectivity, the Gibbs free energy changes of Ti–Fe and Ti–Cu compounds at the weld were calculated from the thermodynamics perspective to determine the possible phases. The temperature field of the joint was also investigated using finite element simulation to analyze the temperature changes in the fusion zone, the interface I (304 SS/AgCuTi), and the interface II (AgCuTi/Al2O3) under different welding parameters, and predict the welding parameters that can achieve an effective connection without destroying the Al2O3 ceramics, which were experimentally verified. The maximum tensile strength of the joints was 94.9 MPa when the laser power was increased from 372 W to 432 W. The maximum tensile strength of the joints was 90.5 MPa when the laser speed was increased from 440 mm/min to 630 mm/min. The maximum tensile strength of the joints was 89 MPa when the laser offset was increased from 1.4 mm to 1.9 mm. By analyzing the microstructure, it was found that brittle intermetallic compounds (IMCs) such as FeTi and Cu2Ti were generated at interface I, which was the main factor affecting the strength of the joint. Many Ag(s,s) and Cu(s,s) solid solutions were found at AgCuTi and interface II. By analyzing the microstructure, the interface organization of the joint is composed of 304 SS + α-Fe/γ-Fe + FeTi/Cu2Ti + Ag(s,s)/Cu(s,s) + Ti2Cu + Al2O3. Finally, the Arrhenius function calculates the diffusion coefficients and diffusion concentrations of Ti and Fe elements.

Essential characteristics of rigid concrete airport pavements under cyclic traffic loading revealed from a thermodynamic perspective

The increasing global air traffic has placed higher demands on airport pavement design. However, the behavior of rigid concrete airport pavement (RCAP) under traffic loading is very complex, and the existing reliability theory and empirical concrete pavement analysis methods cannot detect the precise RCAP failure point. Based on this background, this paper attempts to study the failure of RCAP under traffic loading from a thermodynamic perspective. It selects the Federal Aviation Administration (FAA) test in Construction Cycle 8 (CC8) phase 3 as the research material. We apply the structural stressing state theory to equate the RCAP under traffic loading to a thermodynamic system with a phase transition, i.e., we model the whole process strain data as state variables. Then, analogous to the renormalization group method of Wilson's phase transition theory to reveal the critical point of the system, this study establishes matrixes (Modes) and Hamiltonians (Characteristic parameters) that can characterize the RCAP full-process stressing state evolution under traffic loading by accumulating the difference of state variables. We attempted to verify the effectiveness of this method under such complex working conditions, which can also be applied to many other high-speed time-variant loading conditions. By applying the clustering analysis criterion, we can reveal the phase transition points of the RCAP: elastoplastic branch (EPB), failure starting (FS), and progressive failure (PF) points, respectively. Taking the NW group as an example, the variances of EPB, FS, and PF points revealed by the mode and characteristic parameter curves conducted by the two homogeneous measured point selections, respectively, are 7.7,6.4, and 6.4, which are of exceptionally high stability. We also used thermodynamic modeling to reveal the phase transition points of the remaining three RCAPs and compared the effect of different joints on the phase transition points. Finally, this study also explores the feasibility of EPB-based concrete airport pavement design.

Power-law patterns in the Phanerozoic sedimentary records of carbon, oxygen, sulfur, and strontium isotopes

Power-law patterns appear in a variety of natural systems on the modern Earth; nevertheless, whether such behaviors appeared in the deep-time environment has rarely been studied. Isotopic records in sedimentary rocks, which are widely used to reconstruct the geological/geochemical conditions in paleoenvironments and the evolutionary trajectories of biogeochemical cycles, offer an opportunity to investigate power laws in ancient geological systems. In this study, I focus on the Phanerozoic sedimentary records of carbon, oxygen, sulfur, and strontium isotopes, which have well documented and extraordinarily comprehensive datasets. I perform statistical analyses on these datasets and show that the variations in the sedimentary records of the four isotopes exhibit power-law behaviors. The exponents of these power laws range between 2.2 and 2.9; this narrow interval indicates that the variations in carbon, oxygen, sulfur, and strontium isotopes likely belong to the same universality class, suggesting that these systematic power-law patterns are governed by universal, scale-free mechanisms. I then derive a general form for these power laws from a minimalistic model based on basic physical principles and geosystem-specific assumptions, which provides an interpretation for the power-law patterns from the perspective of thermodynamics. The fundamental mechanisms regulating such patterns might have been ubiquitous in paleoenvironments, implying that similar power-law behaviors may exist in the sedimentary records of other isotopes.

Free Energy Changes at State-Transition Critical Points As a Patient-Specific Biomarker in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is an aggressive hematopoietic malignancy with a poor overall survival rate. AML is a highly heterogeneous disease driven by combinations of genomic mutations, epigenetic alterations, and biochemical signaling. The heterogeneity underlying AML needs novel approaches for individualized clinical assessment and treatment selection. However, approaches that rely on differential expression or correlation analysis lack an underlying theoretical model of the disease to inform the interpretation of ongoing processes in each individual which is crucial for personalized diagnostics and treatment selection. We have previously shown that the state-transition (ST) theory, state-space could predict AML disease evolution using the mRNA of a conditional Cbfb-MYH11 (CM) knock-in mouse model. The ST model represents AML evolution from health to disease as a state transition of the transcriptome state described as a particle undergoing Brownian motion in a double-well quasi-potential, where critical points define states of healthy, c1, transition to AML, c2, and overt AML, c3. We integrated two approaches, the ST model and surprisal analysis (SA) from thermodynamics, to create a patient-specific characterization that can be used to identify the individualized state of the disease. The publicly available datasets of human blood including normal samples, AML samples of bone marrow (BM), and peripheral blood (PB) were utilized for the methods. A total of 858 samples from three publicly available RNA-seq datasets were used. The Therapeutically Applicable Research to Generate Effective Treatments (TARGET) dataset is a pediatric study, from which we analyzed 84 normal samples and 126 AML inv(16) samples, consisting of 105 BM and 21 PB samples with ages from 0.3 to 28 years. Two additional datasets from the BEATAML study and the Cancer Genome Atlas (TCGA), were downloaded from the Genomic Data Commons (GDC) portal using GDCRNATools. The BEATAML dataset included 21 normal and 476 AML samples consisting of 226 PB and 243 BM samples with ages from 2 to 87, and TCGA dataset contained 151 AML PB samples, with ages 21 to 88 years. We used a pseudotime approach to infer disease dynamics for ST using KIT and CD33. We found via t-test analysis that KIT expression between normal and AML samples was significantly different for both TARGET (p<0.01) and BEATAML (p<0.01). CD33 expression between normal and AML samples was significant in BEATAML (p=0.012), but not TARGET (p=0.30). We combined the ST with SA to analyze free energy changes (FEC) that occurred at ST critical points, which predicted AML progression as normal hematopoiesis, c1, transition to AML, c2, and overt AML, c3. Significant differences in FEC at the critical points c1, c2, and c3 were observed by t-test comparisons as c1 vs. c2 (p <0.001) and c1 vs. c3 (p <0.001) in TARGET dataset, and c2 vs. c3 (p < 0.01) in the BEATAML dataset. Our results showed that the transition disease state, c2, had higher FEC as compared to normal states, c1, suggesting that samples were less stable from a thermodynamic perspective. Certain samples at the more advanced state, c3, exhibited a trend toward decreasing FEC levels, suggesting a process of state stabilization at more advanced stages of the disease. SA and Gene Ontology analysis suggested that interleukin pathways such as IL1, IL2, IL8 and IL10, MAPK, NFkB, and migration-related pathways, which are known to be involved in AML progression, were found in multiple unbalanced processes in SA characterizing AML across all three datasets. The IL1 pathway was found in 3 unbalanced processes characterizing TARGET dataset and in four processes characterizing TCGA and BEATAML. IL2 related categories were found among induced transcripts in 4 unbalanced processes characterizing TARGET dataset, in 6 characterizing TCGA, and in 4 processes characterizing BEATAML. We observed that AML samples with comparable FEC levels or clinical characteristics could be defined by different sets of unbalanced processes, implying that this information might be used to determine tailored therapies in subgroups of individuals with similar clinical or thermodynamic characteristics. We showed that mapping FEC into an AML state-space given by ST critical points could provide a high resolution, patient-specific disease characterization, and these methods could be used in personalized diagnostics and individualized treatment procedures.

Understanding the Seeded Heteroepitaxial Growth of Crystallizable Polymers: The Role of Crystallization Thermodynamics.

Seeded heteroepitaxial growth is a "living" crystallization-driven self-assembly (CDSA) method that has emerged as a promising route to create uniform segmented nanoparticles with diverse core chemistries by using chemically distinct core-forming polymers. Our previous results have demonstrated that crystallization kinetics is a key factor that determines the occurrence of heteroepitaxial growth, but an in-depth understanding of controlling heteroepitaxy from the perspective of crystallization thermodynamics is yet unknown. Herein, we select crystallizable aliphatic polycarbonates (PxCs) with a different number of methylene groups (xCH2, x = 4, 6, 7, 12) in their repeating units as model polymers to explore the effect of lattice match and core compatibility on the seeded growth behavior. Seeded growth of PxCs-containing homopolymer/block copolymer blend unimers from poly(ε-caprolactone) (PCL) core-forming seed platelet micelles exhibits distinct crystal growth behavior at subambient temperatures, which is governed by the lattice match and core compatibility. A case of seeded growth with better core compatibility and a smaller lattice mismatch follows epitaxial growth, where the newly created crystal domain has the same structural orientation as the original platelet substrate. In contrast, a case of seeded growth with better core compatibility but a larger lattice mismatch shows nonepitaxial growth with less-defined crystal orientations in the platelet plane. Additionally, a case of seeded growth with poor core compatibility and larger lattice mismatch results in polydisperse platelet micelles, whereby crystal formation is not nucleated from the crystalline substrate. These findings reveal important factors that govern the specific crystal growth during a seeded growth approach by using compositionally distinct cores, which would further guide researchers in designing 2D segmented materials via polymer crystallization approaches.

Feasibility and Performance Analysis of a Dual‐Regulation System in the Process of Methanol and Electricity Coproduction by Coal Gasification

The traditional coal‐gasification process has many problems, such as low yield, large loss of syngas, and large carbon emission. Herein, a novel dual‐regulation system is established. Natural gas is used as the supplemental feed to add hydrogen‐ to coal‐gasification syngas, which is the primary regulation process. Water–gas shift process with calcium looping is treated as the secondary regulation process to regulate the ratio of H2 to CO and CO2 subtly. The potential feasibility of the system is verified through thermodynamic perspective by Aspen Plus. Under the simulation condition, the final methanol product amount is 3485.12 kmol h−1 with 97.2% concentration and 33.47 MWe net electricity is generated. As a result, the methanol efficiency and net electricity efficiency are 60.55% and 3.22%, respectively. For investigating the effectiveness of regulation, the effects of mass ratio of natural to coal feedstock on materials and performances are discussed.

Cleaner and cost-efficient hydrometallurgical process for extraction of vanadium from Bayer vanadium sludge based on BaSO4, NaOH, ammonium, and water circulation

Bayer vanadium sludge(BVS) is a hazardous waste due to its high contents of V, P, As, and F. Full or partial utilization of this sludge could not only minimize the potential environmental risk but also promote resource recycling. In this work, a cleaner and cost-efficient process was proposed to selectively extract vanadium from BVS by employing BaSO4 as precipitant. Under the optimal conditions, a maximum vanadium precipitation efficiency of 97.86% is achieved, whereas only 1.15% arsenate and 0.12% fluoride are co-precipitated. Afterwards, the generation of 2Na3AsO4·NaF·19 H2O and NaSO4·NaF has enhanced the simultaneous removal of As and F during evaporation crystallization, and achieving the recycling of NaOH. A new strategy was adopted to in-situ convert Ba3(VO4)2 into Ba(VO3)2·H2O which can be directly leached in (NH4)2SO4 solution. Furthermore, 99.78% vanadium is precipitated as (NH4)2V6O16 from the leachate and the V2O5 product with a purity of 99.85% is prepared after calcination. The leaching residues and the spent liquor containing large amounts of NH4+ after (NH4)2V6O16 precipitation can be circulated to the next batch of vanadium precipitation and leaching, respectively. Herein, the process realizes the internal circulation of BaSO4, NaOH, ammonium, and water, saving production costs and avoiding environmental pollution.

Construction of walnut protein/tea polyphenol/alginate complex for enhancing heat and gastrointestinal tolerance of lactic acid bacteria

The presence of live cells in the intestinal tract is crucial for the beneficial effects of probiotic products containing lactic acid bacteria. However, many bacterial cells lose viability during production, storage, and gastric passage. Protein-based hydrogels and polysaccharide-based capsules effectively enhance the viability of live probiotic cells in products, but the underlying mechanisms and in vivo effectiveness are unclear. In this study, a complex was developed by self-aggregating walnut protein, tea polyphenol, and Lactobacillus rhamnosus cells under acidic conditions, followed by alginate coating. Complex formation was facilitated by hydrogen bonding and hydrophobic interactions. The complex had a low thermal diffusion coefficient of 4.9 × 10−7 m2/s, making the bacterial cells resistant to temperature fluctuation. Cell survival rate was 75.5% after 12 h at 55 °C and 92.8% after freeze-drying. Shelf-life predictions were 14 years at 4 °C. and 2.3 months at 25 °C, with a live cell count exceeding 106 CFU/g. The product demonstrated a 60% increase in live bacterial cells compared to free cells in simulated gastric fluid, and achieved complete release in simulated intestinal fluid within 120 min. This method was successfully applied to L. rhamnosus, L. casei and L. plantarum. Oral administration of the L. rhamnosus product significantly increased the abundance of Lactobacillus and L. rhamnosus in the colon and cecum of mice. These findings present a new method for producing highly active probiotic products using plant materials and provide insights into the underlying mechanisms from a thermodynamic perspective, contributing to the industrialization and advancement of probiotics.

Removal of aflatoxin B1 from contaminated milk and water by nitrogen/carbon-enriched cobalt ferrite -chitosan nanosphere: RSM optimization, kinetic, and thermodynamic perspectives

In view of the feed/foods inevitably contaminated by toxic and carcinogenic aflatoxin B1 (AFB1), efficient mesoporous metformin-chitosan/silica‑cobalt ferrite nanospheres (Mt-CS/CFS NSs) was prepared to remove AFB1 from aqueous/non-aqueous media. The morphological, functional, and structural characteristics and adsorption properties of C/N-enriched CS/CFS were investigated systematically. The interactive operating variables (temperature (5.0–35 °C); time (10–100 min); AFB1 dose (50–100 μg/mL); and Mt-CS/CFS dosage (0.5–3.5 mg) were optimized via the Box-Behnken design (BBD), which demonstrated good agreement between the experimental data and proposed model. The adsorption efficiency in artificially contaminated cow's milk as well as aqueous environment reached over 91.0 % in a wide pH range (3.0–9.0), without significant change in the nutritional value of milk. Freundlich isotherm and second-order adsorption kinetics were regarded as the most suitable models to fit the adsorption results, and the adsorption rate is dominated by the intra-particle diffusion and boundary layer diffusion. Thermodynamic analyses proved that the process was spontaneous and exothermic. The adsorption mechanism could be explained as physisorption via hydrogen bonding, n-π interaction, and hydrophobic/hydrophilic interactions. The porous Mt-CS/CFS NS derived from chitosan nanoparticles is therefore outstanding adsorbent, offering great adsorptive performance and recycabilities, which impedes economic losses in the food industry.

Process design, integration, and optimization of a novel compressed air energy storage for the coproduction of electricity, cooling, and water

The use of fluctuating renewable energy over a certain threshold may lead to an unmanageable mismatch between the electricity generation and demand profiles threatening the grid's stability. In this study, an innovative complex energy storage/conversion system is proposed for the cogeneration of electricity, cooling, and water by integrating the liquefied natural gas (LNG) regasification process, an organic Rankine cycle, a compressed air energy storage (CAES) system, and a multi-effect distillation unit. The study attempts to minimize the CO2 emission from the CAES technology while addressing interruptions and reductions in the grid upon the extensive use of intermittent renewables. In addition, the proposed system uses excess power and waste heat during the charging and discharging of the CAES to regasify LNG and produce fresh water. The reference system performance is analyzed considering thermodynamic, economic, and environmental perspectives. The multi-objective grasshopper optimization algorithm is used to make a trade-off between the technical, economic, and environmental performance factors of the system. The results show an exergy efficiency of 50.6 % and a total cost rate of 322.8 $/h for the proposed system at the TOPSIS optimal point. The Grassmann diagram indicates the combustion chamber is the main source of irreversibility, and the Chord diagram revealed the discharge unit was responsible for more than 55 % of the total cost.

Biofuel, solar-biofuel or geothermal energy; which resource can better contribute to an integrated energy system for residential energy demands

In this study, an integrated energy system is deployed to generate electricity, heating, cooling, and domestic hot water for a community considering three fully renewable energy source scenarios: biofuel (Case I), solar-biofuel (Case II), and geothermal energy (Case III). The proposed systems are modeled, assessed, optimized, and compared thermodynamically, economically, and environmentally; in addition, a proton exchange membrane electrolyzer (PEME) is utilized to convert the surplus electricity to stored hydrogen to raise the exergy efficiency and package value-added. Mathematical models are fully developed from thermodynamic and economic perspectives, taking a cumulative inflation rate into account via the Consumer Price Index (CPI). The novelty of the study is to focus on the comparison of the proposed renewable resources as energy inputs for the same condition (community loads), as there is a gap in this regard in the literature. Presented systems are optimized using Non-dominated Sorting Genetic Algorithm-II (NSGA-II) for minimum net costs as well as maximum exergy efficiency to reach the optimum operating conditions for each case during the peak cooling and heating loads. Moreover, for a more precise comparison of the proposed cases from an exergetic, economic, and environmental point of view, dynamic (hourly) behaviors of systems are analyzed over a year. A comprehensive parametric study is carried out to reckon the influence of borehole drilling depth, geofluid mass flow rate, and soil temperature gradient on case III to appraise its competitiveness in different locations, as well as the effects of the number of collectors on total cost rate and exergy efficiency for case II. Results indicate the annual net costs of $107.1k, $99.5k, and -$505.1k (where the negative sign stands for "income" instead of "cost") and average exergy efficiencies of 19.1 %, 26.3 %, and 41.3 % for cases I, II and III respectively.

The Elements Selection of High Entropy Alloy Guided by Thermodynamics and the Enhanced Electrocatalytic Mechanism for Oxygen Reduction Reaction

AbstractOwing to their exceptional properties, high‐entropy alloys (HEAs) have received considerable attention in the field of electrocatalysis. However, few studies focus on the origin of their outstanding performance. Here, carbon‐supported PtFeCoNiMn (with an atomic ratio of 21:20:20:20:19) HEA nanoparticles via shock‐heating and shock‐cooling strategy are rationally designed and successfully prepared. The above five metal elements are rationally selected from the perspective of thermodynamics and geometric effects. Subsequently, the alloying process of the PtFeCoNiMn HEA is investigated via operando X‐ray diffraction characterizations. The electronic structures of each metal atom on the PtFeCoNiMn HEA and monometallic nanoparticles surface are revealed by density function theory calculations for illustrating the performance enhancement mechanism. It is found that Pt atoms on the PtFeCoNiMn HEA surface exhibit a wider range of d‐band center distribution range than the corresponding monometallic nanoparticles, which contributes to the enhanced selective adsorption of O2 reactants/intermediates. Importantly, some Fe, Co, Ni, and Mn atoms on the HEA surface manifest less positive d‐band center values than the corresponding monometallic nanoparticles, with similar d‐band center positions to some Pt atoms. This indicates that the inactive atoms in monometallic nanoparticles can be transformed into ORR active sites in the HEA matrix owing to the electronic interaction between adjacent atoms.

Evolution of loess-paleosol sequence from the perspectives of thermodynamics and microstructure

The process of entropy increase can promote the formation and transformation of natural structures, and also provide information on the evolution process of some inherently complex structures in nature. However, this process has rarely been discussed in the evolution of loess-paleosol sequences. In this study, taking the Xiushidu section of Jingyang as an example, we deciphered the evolution process of a loess-paleosol sequence from the perspective of thermodynamics and microstructure. The configuration entropy of microstructure was found to be sensitive to subtle differences and can be regarded as a new climate indicator. In other words, entropy values changed periodically in the loess strata, with paleosol layers showing lower values than the adjacent loess layers. In addition, the relationship between configuration entropy and external entropy flow induced by climatic change played an important role in the evolution of loess-paleosol sequence. During the paleosol development period, the soil structure underwent continuous change driven by strong weathering and pedogenic processes. The significant structural changes might have entered a new orderly state of the system. In contrast, during the loess accumulation period, the external conditions did not satisfy the threshold of qualitative change, and the soil structure continued to develop toward a disordered state. In the context of thermodynamic entropy, the evolution of the loess-paleosol sequence is a result of alternation between the “near disordered state” and “dissipative structure”. Macroscopically, the change process of the geological system was a dynamic cycle: an open system that constantly experienced a cycle of “external entropy input”-“self-adjustment”-“external entropy input”. We define the above entropy change process as a thermodynamic conceptual model of the loess-paleosol sequence evolution. These findings provide a new thermodynamics approach for deciphering loess-paleosol sequences.