Equilibrium Process Research Articles

Beat-to-Beat Blood Pressure Variability Within 24 Hours of Ischemic Stroke Onset: A Potential Predictor of Functional Prognosis.

Beat-to-beat blood pressure variability (BPV) is based on each heartbeat and represents a dynamic equilibrium process modulated by artery and cardiac involvement of pressure-receptive reflexes. To date, there remains a lack of prospective studies illustrating the clinical value of beat-to-beat BPV within 24 hours of acute ischemic stroke onset. This study prospectively monitored beat-to-beat blood pressure and heart rate in patients with acute ischemic stroke within 24 hours of onset using a noninvasive plethysmograph and calculated beat-to-beat BPV, heart rate variability, and the cross-correlation baroreflex sensitivity. A modified Rankin Scale score of ≥2 at 90 days was defined as an unfavorable prognosis. Multivariate logistic regression was performed, and the nomogram model was developed by adding the beat-to-beat BPV to the traditional model for predicting prognosis. Beat-to-beat BPV increased significantly in the unfavorable outcome group (P<0.05) compared with that in the favorable outcome group, whereas no difference was observed in beat-to-beat heart rate variability and cross-correlation baroreflex sensitivity between both groups (P>0.05). Furthermore, beat-to-beat BPV within 24 hours of acute ischemic stroke onset was independently associated with unfavorable outcome at 90 days (P<0.005). The addition of beat-to-beat BPV to the traditional model for predicting prognosis enhanced the area under the receiver operating characteristic curve from 0.816 to 0.830. Increased beat-to-beat BPV within 24 hours of acute ischemic stroke onset was independently associated with a poor prognosis at 90 days and may be a potential predictor for discriminating unfavorable prognosis.

Melt growth of crystalline α-SrSi2 by the vertical Bridgman method and its thermoelectric characteristics

As a candidate thermoelectric material operating in the low-temperature regime (room temperature to 473 K), we have examined α-SrSi2: a narrow bandgap semiconductor material, which is composed of environmentally benign elements. We are able to report the successful production of single-crystalline-like α-SrSi2 with clear semiconducting properties by melting synthesis, a thermodynamically stable and thermally equilibrium process that reduces unexpected process contamination and improves crystallinity.The crystals up to 20 × 20 × 5 mm3 have been obtained for a solid–liquid phase reaction temperature of 1308 K for 10 h with a growth rate averaging at 0.617 K/h in the temperature range from 1403 K to 1373 K. The band gap of this material was measured at 48 meV, which is higher than the values previously reported. The power factor was measured at 2.9 mW/mK2 at 300 K, which is the highest value ever reported for undoped α-SrSi2.Based on the experimental bandgap values, the hybrid functional was used to correct the first-principles calculation method, and the Seebeck coefficient obtained from the first-principles calculation was compared with experimental values. Which values showed good agreement with experimental values.

High‐Resolution In Situ Fe Isotope Measurements of Silicate Minerals and Glasses by Femtosecond Laser Ablation MC‐ICP‐MS

In this study, we present a high precision and high spatial resolution in situ Fe isotope protocol using femtosecond (fs) laser ablation multi‐collector inductively coupled plasma‐mass spectrometry (LA‐MC‐ICP‐MS). The intermediate measurement precision obtained over a period of ca. 3 years for the USGS glass BIR‐1G against the Puratronic reference material is 0.17‰ (2s) for δ56Fe. Uncertainties achieved on individual analyses of glass and olivines were &lt; 0.15‰ for δ56Fe. This high precision is associated with high spatial resolution of about 170 × 25 μm. Our results display good consistency between LA‐MC‐ICP‐MS and solution nebulisation MC‐ICP‐MS data from the literature. Obtained δ56Fe values on different USGS glasses (BIR‐1G, BHVO‐2G and BCR‐2G) show that these reference materials have homogenous Fe isotope ratio and therefore can be used as bracketing calibrators during laser ablation measurement sessions. On the other hand, the San Carlos Olivine displays high Fe isotope heterogeneity, and therefore cannot be considered as a good bracketing standard (calibrator). We also applied our fs‐LA‐MC‐ICP‐MS protocol to olivines and pyroxene from the Kerguelen Archipelago. This technique appears to be a relevant tool to resolve isotopic zoning in chemically zoned silicate phenocrysts, even of small size (&lt; 1 mm). We demonstrate that within single lavas, olivine crystals display various zoning depending on their size, related to their residence time in the magma. Both equilibrium and diffusive processes were observed in olivine crystals from Kerguelen, uncovering complex histories. Hence, iron isotope ratio measurements by fs‐LA‐MC‐ICP‐MS open new possibilities for studying highly zoned silicate minerals in magmatic rocks to better understand their formation.

Molecular Insights into Soaking in Hybrid N2-CO2 Huff-n-Puff: A Case Study of a Single Quartz Nanopore-Hydrocarbon System.

Hybrid N2-CO2 huff-n-puff (HnP) has been experimentally demonstrated to be a promising approach for improving oil recovery from tight/ultratight shale oil reservoirs. Despite this, the detailed soaking process and interaction mechanisms remain unclear. Adopting molecular dynamic simulations, the soaking behavior of hybrid N2-CO2 HnP was investigated at the molecular and atomic levels. Initially, the soaking process of fluid pressure equilibrium after injection pressure decays in a single matrix nanopore connected to a shale oil reservoir is studied. The study revealed that counter-current and cocurrent displacement processes exist during the CO2 and hybrid N2-CO2 soaking, but cocurrent displacement occurs much later than counter-current displacement. Although the total displacement efficiency of the hybrid N2-CO2 soaking system is lower than that of the CO2 soaking system, the cocurrent displacement initiates earlier in the hybrid N2-CO2 soaking system than in the CO2 soaking system. Moreover, the N2 soaking process is characterized by only counter-current displacement. Next, the soaking process of fluid pressure nonequilibrium before the injection pressure decays is investigated. It was discovered that counter-current and cocurrent displacement processes initiate simultaneously during the CO2, N2, and hybrid N2-CO2 soaking process, but cocurrent displacement exerts a dominant influence. During the CO2 soaking process, many hydrocarbon molecules in the nanopore are dissolved in CO2 while simultaneously exhibiting a substantial retention effect in the nanopore. After pure N2 injection, there is a tendency to form a favorable path of N2 through the oil phase. The injection of hybrid CO2-N2 facilitates the most significant cocurrent displacement effect and the reduction in residual oil retained in the nanopore during the soaking process, thus resulting in the best oil recovery. However, the increase rate in total displacement efficiencies of the different soaking systems over time (especially the hybrid N2-CO2 soaking system) was significantly larger before than after injection pressure decays. Additionally, the displacement effect induced by oil volume swelling is significantly restricted before the injection pressure decays compared to the soaking process after the injection pressure decays. This study explains the role of CO2-induced oil swelling and N2-induced elastic energy played by hybrid N2 and CO2 at different stages of the hybrid N2-CO2 soaking process before and after pressure decays and provides theoretical insights for hybrid gas HnP-enhanced recovery. These pore-scale results highlight the importance of injection pressure and medium composition during the soaking process in unconventional oil reservoirs.

Effects of gestational hypothyroidism on mouse brain development: Gabaergic systems and oxidative stress

Hormonal imbalance during pregnancy is a risk factor for neuropsychiatric impairment in the offspring. It has been suggested that hypothyroidism leads to dysfunction of cortical GABAergic interneurons and inhibitory system development that in turn underlies impairment of the central nervous system. Here we investigated how gestational hypothyroidism affected offspring GABAergic system development as well as redox regulation parameters, because of previous links identified between the two. Experimental Gestational Hypothyroidism (EGH) was induced in CD-1 mice with 0.02% methimazole (MMI) in drinking water from embryonic day 9 (E9) until tissue collection at embryonic day 14 (E14) or E18. We examined GABAergic cell distribution and inhibitory system development gene expression as well as redox relevant gene expression and direct measures across all embryos regardless of sex. Intrauterine restriction of maternal thyroid hormones significantly impacted both of these outcomes in brain, as well as altering redox regulation in the placenta. GAD67+ neuronal migration was reduced, accompanied by a disruption in gene expression influencing GABAergic cell migration and cortical inhibitory neural system development. EGH also altered embryonic brain gene expression of Gpx1, Nfe2l2, Cat levels in the dorsal E14 brains. Additionally, EGH resulted in elevated TBARS, Gpx1 and Nfe2l2 in the ventral E18 brains. Furthermore, EGH downregulated placental Gpx1 gene expression at E14 and increased protein oxidation at E18. These findings support the hypothesis that sufficient maternal thyroid hormone supply to the fetus influences central nervous system development, including processes of GABAergic system development and redox equilibrium.

Irreversible and reversible chemical reaction impacts on convective Maxwell fluid flow over a porous media with activation energy

The Maxwell model of fluid flow in a rotating frame over a porous media is investigated in this paper. Binary chemical reactions and fluid movement under activation energy are both covered in this study. The impact of mass and heat transmission along the boundary layer is investigated in an equilibrium process. Using the method of similarity transformation, the controlling partial differential equations are changed into ordinary differential equations. The results are confirmed using the bvp4c Matlab built-in programme, and the altered equations are resolved utilizing a 4th order Runge Kutta based shooting method. Reversible and irreversible processes, activation energy, chemical reactions, Deborah numbers, and rotation parameters are some of the parameters for which the results are offered in tables and graphs. The prior objective of this study is to examine the impact of activation energy and chemical reactions on Maxwell fluid flow in an equilibrium setting. The concentration boundary layer for reversible flows is significantly finer than that of irreversible flows with the influence of activation energy, chemical reaction, and rotation factors. A reduced boundary layer thickness can improve the rates of heat and mass transmission in tremendous applications, such as exchangers of heat and chemical reactors. In this chemical process, sulphuric acid is utilized as a catalyst along with Maxwell fluid which affects the boundary layer reaction rate and selectivity. This is crucial for efficient catalytic process design. Controlling reaction rates using fluid elasticity and reaction kinetics is useful in operations that need accurate product production.

The Leadership Triad: A Relational Model

Eric Berne introduced some specific ideas about leadership of groups and organizations into the field of transactional analysis. The author outlines Eric Berne’s three kinds or types of leadership as part of the group authority. This concept is subsequently linked to anthropological research, resulting in an archetype interpretation of the three kinds of leadership. On that basis, the author introduces the leadership triad as a relational model of leadership, consisting of representative, executive, and transformative leadership. The foundation of this model is a systemic interpretation with all three functions as a dynamic equilibrium or homeostatic process of cocreating cohesion. The model suggests that leadership is a cocreated, resonant group process with the whole team sharing – and not only a leader having – responsibility for the successful development of the team or the organization. Finally, implications of leadership imbalance are conceptualized and illustrated by case examples.

Seasonal oxidative dynamics and isotopic fractionation of NOx and SO2 in Ostrava, Czech Republic: Insights from stable isotope analysis

The city of Ostrava, NE Czech Republic, is known for its industrial pollution. It has well-characterized emission sources and stable air movement patterns. These features are conveniently used to generalize on atmospheric NOx and SO2 oxidation processes. In 2021, we conducted a series of sampling campaigns to assess the isotopic fractionation conducive to NO3− and SO42− aerosols in PM10. These sampling campaigns were timed to capture varying atmospheric conditions, including climatic inversion periods, providing also insights into urban emission dynamics over the course of the year. Gaseous NOx and SO2 were collected on passive filters, while their oxidized forms, NO3− and SO42, were captured on PM10 particle filters, enabling us to analyze the transformation dynamics of these pollutants. Isotopic analyses distinguished the sources of NOx emissions—coal combustion (δ15N = −3‰) and vehicular emissions (δ15N = −7 ‰)—and allowed quantifying isotope fractionation during their conversion to NO3− (εNOx-NO3- = 11.5 ± 1.15 ‰). This fractionation, however, was influenced by seasonal variations, and appears to be notably affected by NH4NO3 decomposition during warmer months. The correlation of the NO3− to NOx ratio with PM10 and atmospheric moisture highlighted the interplay between particulate matter and humidity in relevant atmospheric transformations. Similarly, for SO2, primarily emitted from coal combustion (δ34S = −2‰), we identified distinct fractionation patterns during oxidation to SO42− encompassing both kinetic (εSO2-H2O = −1.3 ± 0.5‰) and equilibrium (εSO2- SO42- = 2.24 ± 0.67‰) effects. The SO42−/SO2 ratio was correlated with PM10 but showed no dependence on humidity. Significantly, atmospheric inversion conditions accelerated oxidation, modifying the fractionation patterns for both NOx (εNOx-NO3- = 7‰) and SO2 (εSO2- SO42-= −0.9 ± 0.3‰). Our methodology elucidates pivotal mechanisms in atmospheric pollution transformation, underlined by the tracing of NOx and SO2 to aerosol conversions via δ15N and δ34S isotopic analyses. The isotope fractionation underscores equilibrium processes in oxidation reactions, while the effect of PM10 and humidity reveals the complexity of these atmospheric oxidative transformations. The role of wet deposition in removing SO2 highlights an essential pathway in the atmospheric sulfur cycle.

Removal of Herbicide from Aqueous Solution Using Granular Activated Carbon: Equilibrium Data and Process Design

2,4-Dichlorophenoxyacetic acid (2,4-D) herbicide is a widely utilized herbicide known to be moderately toxic, have extensive use, poor biodegradability, and h led to contamination of surface and ground waters. The Granular Activated Carbon (GAC) was characterized by its porosity, surface morphology, and availability of functional groups. Type I isotherm was observed in the GAC, indicating microporosity with specific a surface area of 832.35 m2/g and pore diameter of 0.899 nm. GAC was evaluated for its ability to adsorb herbicide 2,4-D as the model adsorbate and evaluated the effects of initial concentration, contact time, pH, and activated carbon dosage on the adsorption process. According to the results, 94.01 %, 97.17%, 97.76 %, 98.15%, and 98.2 % of the adsorptive removal were achieved at initial concentrations of 10, 20, 30, 40, and 50 mg/l, respectively. Langmuir and Freundlich isotherm models were used to analyze the adsorption isotherm. It was determined that 2,4-D had a maximum monolayer adsorption capacity of 20.28 mg/g for GAC. Freundlich isotherm model predicted uniform binding energy distribution over heterogeneous surface binding sites for the best fit. The Freundlich model was used to design a batch adsorber capable of removing 2,4-D from effluent solutions of different volumes using the required mass of GAC. Resulting of the achieved results, GAC is a highly effective adsorbent for the removal of 2,4-D from aqueous environments.

The evolution of the ambidextrous innovation synergy strategy of new entrants from the perspective of key core technology monopoly

Ambidextrous innovation synergy is an effective way for new entrants and R&D entities to break the blockade of key core technologies. This paper constructs a tripartite evolutionary game model of new entrants, the R&D entity, and monopoly enterprises under the monopoly situation of key core technologies, discusses the dynamic equilibrium process of how new entrants cooperate with the R&D entity to carry out the ambidextrous innovation synergy strategy, and extends the model to the policy subsidy situations of different development stages of key core technology. The results show that the monopoly of key core technologies enhances the original innovation search ability of new entrants and promotes the evolution of enterprise imitation innovation to the exploratory innovation strategy. In the basic research stage of key core technology, the exploratory innovation strategy of new entrants is more sensitive to the cost of network embedding and the original innovation knowledge search. New entrants prefer the imitation innovation strategy, and policy subsidies have no significant effect on exploratory innovation. In the promotion stage of the key core technology market, fiscal and tax subsidies can more easily promote the evolution of new entrants from the imitative innovation strategy to the exploratory innovation strategy than R&D subsidies, and network embeddedness can induce enterprises to carry out exploratory innovation only when a certain threshold is reached. In addition, this paper discusses the influence mechanism of monopoly enterprises' suppression intensities and key core technology breakthrough probabilities on the evolution equilibrium of new entrants' ambidextrous innovation synergy strategies.

Oxygen-enhanced dissolution corrosion of austenitic stainless steel 316 L in static lead-bismuth eutectic at 500 °C

The corrosion process of 316 L austenitic stainless steel in liquid lead-bismuth eutectic at 500°C with dissolved oxygen concentrations ranging from below 10−11 to 10−5 wt% was investigated. The maximum dissolution corrosion damage and the highest oxygen consumption during the experiments occurred at intermediate dissolved oxygen concentrations (10−7 and 10−6 wt%). An assumption of a governing role of Fe3O4 equilibrium and diffusion-limited processes on the steel surface explains quantitatively this observation. The proposed mechanism suggests that oxygen-enhanced dissolution is a result of the combination of solid steel dissolution and the oxidation of dissolved steel constituents in the liquid metal bulk.

Strengthening, strain hardening and fracture of heat-treated interstitial-free steel with massive ferrite conceptualizing the interface controlled reaction phenomena

Interstitial-free steel is extremely soft and ductile with allotriomorphic ferrite in the microstructure as a diffusional transformation product of austenite. In order to alter the mechanical property, the present work performed austenitization of the steel at 925 °C for 5 min and thereafter a rapid water quenching, resulting in massive ferrite. The yield strength (86 MPa) and ultimate tensile strength (181 MPa) increased to 362 MPa and 531 MPa, respectively, along with 18 % ductility. The statistically stored dislocation density and substructures (sub-boundaries, cells) at the grain body contributed 68 % of the yield strength. The strain hardening was observed to be lower than that with allotriomorphic ferrite, due to heterogeneous deformation of the substructures, causing an inhomogeneous distribution of geometrically necessary dislocation density at the bulk. The preferential localization of strain at cell walls initiates cracks by the de-cohesion of massive grains. The cell-substructure conceived by massive ferrite therefore has a strong role both in strain hardening and fracture. The larger the grain size is, the more the cell-substructure is, dictated by an interface-controlled growth of austenite to massive ferrite. The atomic jump at the transformation interface is usually considered to be an equilibrium process; meaning slow, not standing with the so-called faster growth kinetics of an interface-controlled reaction. In order to bridge the gap, the present work demonstrates a slip deformation at the transformation interfaces for fast-tracking the lattice reconstruction of massive ferrite from austenite, a novel.

Detection of metastable solid solution in doped LiFePO4 by synchrotron nuclear resonance techniques

In this work we study one of the popular cathode materials based on doped lithium iron phosphate LiFexMn1-xPO4. Synchrotron operando Mössbauer measurements reveal the existence of metastable states at different stages of the charge and discharge processes, with a lifetime in a wide range from 5 to 140 min. The existence of such states is associated with the formation of a metastable solid solution with the composition LiyFexMn1-xPO4 during cycling. Afterwards, this solution dissolves due to the slow diffusion of manganese and iron ions together with lithium. The presence of metastable states and their rapid decay indicate that cycling is not an equilibrium process. The influence of the manganese migration on the mechanism of the cycling process is discussed in this study.

The thermal equation of state of xenon: Implications for noble gas incorporation in serpentine minerals and their transport to depth

Isotopic signatures of heavy noble gases in the Earth's mantle contain a major component recycled by subduction. The experimental and field studies reported in the literature show increasing evidence that serpentine minerals can hold large quantities of noble gases, potentially serving as their primary vectors to depth. However, at present, their retention mechanism in these minerals is not fully understood. Additionally, noble gas solubilities from field and experimental studies show large differences in terms of elemental concentrations. Here, we performed crystal chemical modeling to evaluate the incorporation mechanism of noble gases and their solubilities in serpentine minerals along subduction zone geotherms. To this end, we determined the thermal equation of state of xenon using in situ X-ray diffraction and absorption up to 60 GPa and 728 K. In this range, the xenon equation of state is well-adjusted using the Mie-Grüneisen-Debye formalism with relevant fitting parameters. We show that the experimentally observed solubility trend, which follows the order Ne < He < Ar < Kr < Xe, can be explained by the incorporation of noble gases at two distinct crystallographic sites. The light noble gases He and Ne are most likely retained at the van der Waals hydrogen-oxygen bond position between the layers, while the heavy and larger noble gases enter the voids between the six-membered SiO4 rings. It should be noted that octahedral sites can potentially host xenon, but cannot accommodate argon and krypton. Indeed, this would require unrealistic flexibility of the crystal lattice. Our models extended to mantle wedge conditions predict decreasing solubilities, particularly for light noble gases, in agreement with observations from natural samples. Compared to the noble gas concentrations determined experimentally in serpentine, natural concentrations are much higher and very variable. Our solubility model confirms that equilibrium processes cannot explain these observations. We therefore suggest that the high and variable noble gas concentrations found in natural samples must be due to hybrid hydration processes in ultramafic rocks that involve different degrees of water activities.

On the thermodynamic equilibrium of thermal casting processes

Based on thermodynamic calculations, it is shown that heating and cooling of metals and alloys are reversible, equilibrium processes. Based on thermodynamic calculations, it is shown that melting and crystallization of metals and alloys are also reversible, equilibrium processes. With an increase in the cooling rate of the metal, the temperature of its equilibrium crystallization decreases. At a high rate of metal cooling, a short‑term initial process of nonequilibrium crystallization is observed, which quickly passes into the main stage of equilibrium crystallization.

Understanding the Differences of Danusertib's Residence Time in Aurora Kinases A/B: Dissociation Paths and Key Residues Identified using Conventional and Enhanced Molecular Dynamics Simulations.

The accurate experimental estimation of protein-ligand systems' residence time (τ) has become very relevant in drug design projects due to its importance in the last stages of refinement of the drug's pharmacodynamics and pharmacokinetics. It is now well-known that it is not sufficient to estimate the affinity of a protein-drug complex in the thermodynamic equilibrium process in in vitro experiments (closed systems), where the concentrations of the drug and protein remain constant. On the contrary, it is mandatory to consider the conformational dynamics of the system in terms of the binding and unbinding processes between protein and drugs in in vivo experiments (open systems), where their concentrations are in constant flux. This last model has been proven to dictate much of several drugs' pharmacological activities in vivo. At the atomistic level, molecular dynamics simulations can explain why some drugs are more effective than others or unveil the molecular aspects that make some drugs work better in one molecular target. Here, the protein kinases Aurora A/B, complexed with its inhibitor Danusertib, were studied using conventional and enhanced molecular dynamics (MD) simulations to estimate the dissociation paths and, therefore, the computational τ values and their comparison with experimental ones. Using classical molecular dynamics (cMD), three differential residues within the Aurora A/B active site, which seems to play an essential role in the observed experimental Danusertib's residence time against these kinases, were characterized. Then, using WT-MetaD, the relative Danusertib's residence times against Aurora A/B kinases were measured in a nanosecond time scale and were compared to those τ values observed experimentally. In addition, the potential dissociation paths of Danusertib in Aurora A and B were characterized, and differences that might be explained by the differential residues in the enzyme's active sites were found. In perspective, it is expected that this computational protocol can be applied to other protein-ligand complexes to understand, at the molecular level, the differences in residence times and amino acids that may contribute to it.

A versatile study of single and binary removals of Pb(II) and Cd(II) ions from aqueous solutions using pine cone as biosorbent

A naturally occurring biosorbent (pine cone) was utilized to remove single and binary Pb(II) and Cd(II) ions from aqueous solutions. The biosorbent has been examined using ATR-IR, SEM, XRD, and pHpzc. The impacts of process factors such as contact time, pH value, biosorbent dosage, initial concentration, and medium temperature on the biosorption of Pb(II) and Cd(II) ions were researched. Langmuir and Freundlich's isotherms were implemented to describe the equilibrium process. At the most favorable condition for each metal, the Langmuir isotherm yielded a maximum loading capacity (qmax) of 43.47 mg/g for Pb(II) and 32.89 mg/g for Cd(II). The highest biosorption was reached with a single system and then reduced in the presence of coexisting ions in the mixtures under optimal conditions. Desorption studies show that 0.5 M HNO3 is the most effective way to remove heavy metals from a biosorbent loaded with metal ions. Thermodynamic parameters (ΔH°, ΔS°, and ΔG°) calculated from temperature data indicate that the biosorption mechanism is exothermic for Pb(II) and endothermic for Cd(II), spontaneous and favorable.

Water absorption in artificial composites: Curse or blessing?

ObjectivesThis study evaluated the impact of mutable water uptake on the durability of mechanical properties and the long-term reliability of artificial composites. MethodsThree resin-based CAD/CAM restorative materials (CRMs) were investigated in three-point bending tests to calculate flexural strength (FS), modulus of elasticity (ME), modulus of resilience (MR), modulus of toughness (MT), and elastic recovery (ER). All specimens (n = 180) were stored under the same conditions and tested in four subsets (n = 15 per material) that were respectively withdrawn after repeated thermocycling (5000 cycles; 5–55 °C, H2O) and repetitive drying (7 d; 37 °C, air). For every specimen, weight differences were determined per storage condition. Likewise, loss tangent data were separately recorded via dynamic mechanical analysis to reliably assess damping characteristics. ResultsRepeated thermocycling always induced weight increase and a concurrent significant loss in all mechanical properties except for MT and ER of a polymethylmethacrylate-based CRM. Drying consistently provoked weight loss and raised mechanical properties to initial values. Weight increase, however, enhanced loss tangent values and accordingly distinct damping characteristics, whereas weight decrease markedly lowered damping properties. SignificanceWater uptake repeatedly induced a decrease in common mechanical properties but concurrently increased damping behavior. Invertible equilibrium processes were found with no evidence for permanent material degradation.

The pseudospectra of black holes in AdS

We study the stability of quasinormal modes (QNMs) in electrically charged black brane spacetimes that asymptote to AdS by means of the pseudospectrum. Methodologically, we adopt ingoing Eddington-Finkelstein coordinates to cast QNMs in terms of a generalised eigenvalue problem involving a non-selfadjoint operator; this simplifies the computation significantly in comparison with previous results in the literature. Our analysis reveals spectral instability for (neutral) scalar as well as gravitoelectric perturbations. This indicates that the equilibration process of perturbed black branes is sensitive to external perturbations. Particular attention is given on the hydrodynamic modes, which are found to be the least unstable. In contrast with computations in hyperboloidal coordinates, we find that the pseudospectral contour lines cross to the upper half plane. This indicates the existence of pseudo-resonances as well as the possibility of transient instabilities. We also investigate the asymptotic structure of pseudospectral contour levels and we find remarkable universality across all sectors, persistent in the extremal limit.

Phase equilibrium data prediction and process optimizationin butadiene extraction process

In response to the lack of reliable physical parameters in the process simulation of the butadiene extraction, a large amount of phase equilibrium data was collected in the context of the actual process of butadiene production by acetonitrile. The accuracy of five prediction methods, UNIFAC, UNIFAC-LL, UNIFAC-LBY, UNIFAC-DMD, and COSMO-RS, applied to the butadiene extraction process was verified using partial phase equilibrium data. The results showed that the UNIFAC-DMD method had the highest accuracy in predicting phase equilibrium data for the missing system. COSMO-RS predicted multiple systems showed good accuracy. And a large number of missing phase equilibrium data were estimated using the UNIFAC-DMD method and COSMO-RS method. The predicted phase equilibrium data were checked for consistency. The NRTL-RK and UNIQUAC thermodynamic models were used to correlate the phase equilibrium data. Industrial device simulations were used to verify the accuracy of the thermodynamic model applied to the butadiene extraction process. The simulation results showed that the average deviations of the simulated results using the correlated thermodynamic model from the actual values were less than 2% compared to that using the commercial simulation software Aspen Plus and its database. The average deviation was much smaller than that of the simulations using the Aspen Plus database (>10%), indicating that the obtained phase equilibrium data are highly accurate and reliable. The best phase equilibrium data and thermodynamic model parameters for butadiene extraction are provided. This improves the accuracy and reliability of the design, optimization and control of the process, and provides a basis and guarantee for developing a more environmentally friendly and economical butadiene extraction process.