Thermodynamic Perspective Research Articles

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.

Advanced Exergy-Based Analysis of an Organic Rankine Cycle (ORC) for Waste Heat Recovery.

In this study, advanced exergy and exergoeconomic analysis are applied to an Organic Rankine Cycle (ORC) for waste heat recovery to identify the potential for thermodynamic and economic improvement of the system (splitting the decision variables into avoidable/unavoidable parts) and the interdependencies between the components (endogenous and exogenous parts). For the first time, the advanced analysis has been applied under different conditions: constant heat rate supplied to the ORC or constant power generated by the ORC. The system simulation was performed in Matlab. The results show that the interactions among components of the ORC system are not strong; therefore, the approach of component-by-component optimization can be applied. The evaporator and condenser are important components to be improved from both thermodynamic and cost perspectives. The advanced exergoeconomic (graphical) optimization of these components indicates that the minimum temperature difference in the evaporator should be increased while the minimum temperature difference in the condenser should be decreased. The optimization results show that the exergetic efficiency of the ORC system can be improved from 27.1% to 27.7%, while the cost of generated electricity decreased from 18.14 USD/GJ to 18.09 USD/GJ.

First-principles study on interfacial property in MgB2-based reactive hydride composites

The underlying physico-chemical interactions between transition metal-based boride particles that formed during the dehydrogenation process and MgB2 in 2LiBH4+MgH2 reactive hydride composite at the atomic scale are still unknown. In this work, the properties of the TiB2/MgB2 interface were investigated by first-principles calculations utilizing density functional theory (DFT). Taking the two terminations of both MgB2 and TiB2 as well as four different stacking sequences into account, energies of the TiB2 and MgB2 (0001) surfaces as well as the work of adhesion and the electronic structure of the interfaces were studied. The results show that the interface between the B-terminated MgB2 (0001) surface and the Ti-terminated TiB2 (0001) surface is the energetically most favorable among all four stacking options and possesses the largest work of adhesion. Our results further show that the TiB2 particles possess good nucleation potency for MgB2 particles from the thermodynamic perspective.

Study of self-assembling properties of HBc-VLP derivatives aided by molecular dynamic simulations from a thermodynamic perspective

Self-assembling protein nanoparticles showed promise for vaccine design due to efficient antigen presentations and safety. However, the unpredictable formations of epitopes-fused protein assemblies remain challenging in the upstream design. This study suggests employing molecular dynamic (MD) simulations to investigate the assembly properties of Hepatitis B core protein (HBc) from thermodynamic perspectives. Eight HBc derivatives were expressed in E. coli, with their self-assembly properties characterised by high-performance liquid chromatography and transmission electron microscopy. MD simulations on the dimers, based on AlphaFold-predicted 3D structures, analysed the derivative at the atomic level. Results revealed that HBc derivatives can form dissociative polymers or large multi-subunit structures due to assembly failures. The instability of the dimer in aqueous solvents or inappropriate intradimer distances could cause major assembly failures. Polar solvation energies played a vital role too in forming assemble-incompetent dimers. Importantly, our study demonstrated that MD simulations on dimers can provide preliminary predictions on the assembly properties of HBc derivatives, thus aiding vaccine design by lowering the risk of self-assembling failures in engineered proteins. Communicated by Ramaswamy H. Sarma

Binding Thermodynamics of Ferrocenyl Ammoniums by Sulfonated Calix[4]arenes

AbstractThe binding constants (Ka), standard molar enthalpy changes (ΔH°), and entropy changes (TΔS°) between two sulfonated calix[4]arene hosts including rigid p‐sulfonatocalix[4]arene (SC4A) and flexible p‐sulfonatothiacalix[4]arene (STC4A), and three ferrocenyl ammonium guests modified by different aliphatic chains were determined in aqueous solution (pH 7.0 and pH 2.0) by isothermal titration microcalorimetry (ITC). The gained data indicated that for the flexible host STC4A, the host‐guest binding affinities increased with the increase of length of the aliphatic chain of guests whereas the rigid host SC4A behaved almost oppositely. Compared with those at pH 2.0, the binding affinities between the hosts and the guests were much stronger at pH 7.0. This should be attributed to the higher π‐electron density and the extra negative charge of calixarene cavities owing to one of the phenolic hydroxyl groups is deprotonated at pH 7.0, thus affording stronger π⋯π, C−H⋯π and electrostatic interactions. Job plot and ITC confirmed that the molecular binding were stoichiometric 1 : 1 between hosts and guests. NMR experiments showed that the signals of the guest protons with addition of hosts underwent pronounced upfield shifts suggesting the effective binding between hosts and guests. In addition, the molecular selective binding behavior was discussed from the perspective of thermodynamics.

Liquid–Liquid Equilibrium in Xylene Solubles (XS) Analysis of Polypropylene

AbstractA multicomponent Flory‐Huggins model is implemented and utilized to describe the liquid–liquid equilibrium phenomenon in mixtures of polypropylene and xylene, in the context of the well‐known xylene solubles (XS) test. The XS experiment is a common procedure in many polymer laboratories, used to determine the percentage of xylene solubles in samples of polypropylene, which provides an approximate measure of the atactic and oligomeric chains. Despite the importance of the test, the literature lacks a thermodynamic perspective regarding the description of this extraction phenomenon. In the present study, the Flory‐Huggins interaction parameter is adjusted in a multicomponent framework to ensure that equilibrium chain length distributions calculated with the proposed model best match experimental distributions. It is shown that the experimental data obtained from XS analyses can be accurately fitted by the proposed model and that the estimated Flory‐Huggins interaction parameter is more sensitive to the polymer average molar mass than to the degree of tacticity, when a particular catalyst is considered.

Quantum entropy evolution in the photovoltaic process of a quantum dot photocell

For efficient photovoltaic conversion, it is important to understand how quantum entropy-related quantities evolve during the photovoltaic process. In this study, using a double quantum dot (DQD) photocell model, we explored the dynamic quantum entropy-related parameters during the photovoltaic output. The findings demonstrate that the dynamic photovoltaic performance is compatible with quantum entropy-related parameters with varying tunneling coupling strengths, but at varied ambient temperatures, an opposing relationship is discovered between them. Hence, some thermodynamic criteria may be used to evaluate the photovoltaic process in this proposed photocell model. This work's merits include expanding our understanding of photoelectric conversion from a thermodynamic perspective as well as perhaps suggesting a new thermodynamic approach to efficient photoelectric conversion for DQD photocells.

The crucial role of different NaOH activation pathways on the algae-derived biochar toward carbamazepine adsorption

In this study, algae present in wastewater were utilized as precursors for synthesizing a range of biochar (BC) samples to serve as efficient adsorbents for the removal of carbamazepine (CBZ). The impact of modification on BC, activated through the NaOH impregnation method (IBC), and the NaOH dry mixing-pyrolysis (DBC) method, was systematically explored. It was observed that only the surface of IBC became rough due to NaOH impregnation activation, while the DBC structure exhibited additional fine pores within its interior. Furthermore, after NaOH activation, a significant number of oxygen-containing functional groups were introduced onto the surface of the prepared BC samples, with the proportion of O species differing between the two NaOH activation methods. Based on the results from adsorption experiments and kinetic model simulation, CBZ adsorption by BC samples followed a monolayer homogeneous adsorption reaction with excellent pH tolerance, where H-bond (CO⋯H–N) was identified as the primary driving force. From an adsorption thermodynamics perspective, it is hypothesized that the high proportion of CO causes the ΔG value to shift from positive to negative, indicating that CBZ adsorption by DBC is a spontaneous reaction. Under optimal conditions, the DBC samples demonstrated an exceptional adsorption capacity, reaching 118.4 mg/g, with the removal rate of CBZ exceeding 99 %. This study offers theoretical insights into the preparation, modification, and adsorption mechanisms of BC-based adsorbents.

Species entropy and thermodynamics

We analyse particle species and the species scale in quantum gravity from a thermodynamic perspective. In close analogy to black hole thermodynamics, we propose that particle species have an entropy and a temperature, which is determined by the species scale. This is identical to the Bekenstein-Hawking entropy of a corresponding minimal black hole and agrees with the number of species in a given tower of states. Through the species entropy, we find that certain entropy bounds are connected to recent swampland constraints. Moreover, the concept of species entropy and temperature allow us to formulate the laws of species thermodynamics, which are argued to govern the variations of moduli in string theory. They can be viewed as general rules that imply certain swampland conjectures, and vice versa.

Experimental and computational analysis of stacking fault energy in B-doped Fe50−XMn30Co10Cr10BX multi-principal elements alloys

The effect of boron doping in Fe50−XMn30Co10Cr10BX multi-component alloys on the resulting stacking fault energy has been experimentally and computationally assessed to understand the alloys' deformation mechanisms from structural and thermodynamic perspectives. Firstly, the fcc and hcp phases were identified together with stacking faults along their (110) planes using high-resolution transmission electron microscopy. At the same time, they were theoretically predicted through thermodynamic CALPHAD and ab initio calculations. The average stacking fault energy for the boron-free alloy was 23.9 ± 2.4 mJ/m2, suggesting that the deformation mechanisms relate to dislocation slip and deformation twinning. The average stacking fault energy for the highest boron content (5.4 at%) was 50.1 ± 14.1 mJ/m2, indicating dislocation glide as the possible deformation mechanism. The boron content in the solid solution was modelled. The modelling suggested that the presence of Cr-B, Mn-B and Fe-B bonds points towards forming (Cr,Fe)2B borides, which was experimentally confirmed. The borides, fcc phase stability, and the boron in solid solution contribute to increased stacking fault energy, preventing the motion of Shockley partial dislocations and influencing the ɛ-hcp martensitic transformation.

Atmospheric Latent Energy Transport Pathways into the Arctic and Their Connections to Sea Ice Loss during Winter over the Observational Period

Abstract To investigate patterns of horizontal atmospheric latent energy (LE) transport toward the Arctic, we applied the self-organizing maps (SOM) method to the daily vertically integrated horizontal LE flux from ERA5 in winter (January–March) during 1979–2021. A clear picture depicting the LE transport to the Arctic at a synoptic scale then emerged, with four primary transport pathways identified: the northern Europe, the Davis Strait, the Greenland Sea, and the Bering Strait pathways. The four primary pathways occurred at a comparable frequency, and noticeable interannual variability was observed in their time series of frequency during 1979–2021. Further analysis suggested that the northward LE transport through all these pathways is significantly modulated by cyclones, with the northern Europe and the Greenland Sea pathways being mostly affected. Generally, more frequent and stronger cyclones were observed near the entry regions of LE transport compared to other regions. Moreover, this study provides a comprehensive picture of how atmospheric LE transport is related to air temperature, moisture, surface heat flux, and sea ice anomalies over the Arctic Ocean in winter. Through a thermodynamic perspective, we argue that the deleterious impacts of poleward LE transport on Arctic sea ice are to a large extent attributable to the enhanced local atmosphere–ice interactions, which increase downward longwave radiation (DLR) plus turbulent fluxes, consequently warming the surface and promoting the loss of sea ice. According to the quantitative results, among the four primary pathways, LE transport through the Davis Strait and the Greenland Sea could cause the loss of Arctic sea ice most efficiently.

Interpretasi Atom dalam Kajian Surat Aż-Żāriyāt

This research was conducted as an effort to obtain a reading material related to thermodynamics so that it can be more easily understood by students or other readers. In conducting research, a researcher needs to follow the rules and regulations that apply so that the results obtained can be said to be valid. This research was conducted using the literature review method, namely by looking for sources that lead to a literature review of the basic concepts of thermodynamics which in this search are very important and much needed. The results of this study are that there are implications or connectedness between the concept of a single particle system and thermodynamics. Single particle systems trapped in a potential well can be explained or understood from a thermodynamic perspective.

Measurement of SnO Activity Coefficient in CaO–SiO2–FetO–Al2O3 Slag Saturated with Fe

It is important to clarify the behavior of elements in the reaction between molten CaO–SiO2–FetO–Al2O3 slag and liquid metal during the remelting of Cu scrap. To estimate the desirable slag composition for retaining Sn in metal, the effects of the slag basicity and the concentrations of FetO and Al2O3 on the SnO activity coefficient were investigated. Molten CaO–SiO2–FetO slag (with optional Al2O3 addition) was reacted with liquid Pb–Sn alloy in a pure Fe crucible at 1573 K for 5 h while blowing the CO–CO2 mixture. From the activity coefficients of Sn, Pb, and Fe oxides in the slag, which were calculated using the PCO/PCO2 ratio during heating and the chemically analyzed compositions of slag and metal, their behaviors in slag/metal reaction were discussed. The order of reducibility was PbO > SnO >> FetO. Finally, it was suggested from the thermodynamic and industrial smelting perspectives that the slag condition favorable to SnO reduction is high basicity, around 50 mass% FetO, and low Al2O3 content.Graphical

Use of different food wastes as green biosorbent: isotherm, kinetic, and thermodynamic studies of Pb2.

Lead (Pb2+) can contaminate waters from many sources, especially industrial activities. This heavy metal is an amphoteric, toxic, endocrine-disrupting, bioaccumulative, and carcinogenic pollutant. One of the effective and economical processes used to remove lead from water is adsorption. The fact that the adsorbents used in this method are easily available and will contribute to waste minimization is the primary reason for preference. In this study, the adsorption abilities and surface properties of tea waste (TW), banana peels (BP), almond shells (AS), and eggshells (ES) which are easily available do not need modification and have very high (> 90%) removal efficiencies presented with isotherm, kinetic, and thermodynamic perspectives as detail. The surface structures and elemental distribution of raw adsorbents were revealed with SEM/EDX. Using FTIR analysis, carboxylic (-COOH) and hydroxyl groups (-OH) in the structure of TW, AS, BP, and ES were determined. It was determined that the Pb2+ adsorption kinetics conformed to the pseudo-quadratic model and its isotherm conformed to the Langmuir. The optimum adsorption of Pb2+ was ranked as BP > ES > AS > TW with 100, 68.6, 51.7, and 47.8mg/g qm, respectively. The fact that the process has negative ΔG° and positive ΔH° values from a thermodynamic point of view indicates that it occurs spontaneously and endothermically. According to the experimental data, the possible adsorption mechanism for Pb2+ has occurred in the form of physisorption (van der Waals, electrostatic attraction) and cooperative adsorption including chemisorption (complexation, ion exchange) processes.

Simulation and multi-objective assessment of an environmentally friendly trigeneration system powered by biogas from landfilling using a novel cascade heat integration model

This study introduces a novel integrated trigeneration system fed by biogas fuel from landfilling, promoting environmentally sustainable practices. In the system proposed within this study, fuel combustion occurs through the implementation of a gas turbine cycle, while the subsequent waste heat is efficiently recuperated within a cascade framework. The combustion process is combined with a supercritical carbon dioxide cycle, an organic Rankine cycle, an ammonia Rankine cycle, a seawater desalination unit, and a Kalina cycle. The process is simulated using the Aspen HYSYS software while conducting a comprehensive analysis encompassing the energy, exergy, economic, and environmental aspects. In view of the thermodynamic perspective, the analysis yields values of 70.28%, 24.89%, and 57.51% for the energy utilization factor, and thermal and exergy efficiencies, respectively. The subsequent environmental results illustrate that the proposed scheme exhibits a carbon dioxide emission level of 0.272 kgCO2/kWh, yielding a noteworthy reduction of 51.02% in carbon dioxide emissions compared to a traditional power and heat generation system. Besides, the economic analysis demonstrates a positive net present value of 779, 571, 045 $ for the proposed process. Furthermore, the total unit cost of products and cost of energy are found at 12.25 $/GJ and 0.022 $/kWh, respectively.