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In this paper, pre‐oxidation treatment was carried out at 950 °C under oxygen pressure of 10−16 atm for nickel‐10 % chromium‐x % aluminium‐1 % silicon‐0.5 % yttrium(x=0 wt.–%, 1 wt.–%, 3 wt.–%, 5 wt.–%) alloys. Morphology and structure of oxide layers on the alloys after pre‐oxidation were analyzed by scanning electron microscopy and electron discharge spectroscopy. The results showed that a chromium oxide film was formed on the surface of the alloy without aluminium addition, while the oxide layer on the surface of the alloy with aluminium addition gradually transformed into M2O3 (M=aluminium and chromium) oxide film. The oxidation behavior was analyzed by means of chemical thermodynamics, and it was seen that because the interaction coefficient,εijof aluminium and chromium is a positive value, the increase of aluminium addition will strengthen the interaction and increase the diffusion coefficient,Diof aluminium and chromium. The diffusion of chromium and aluminium in each other therefore promotes their interaction, which is beneficial to the formation of the outer oxide film. Thus, with the increase of aluminium addition, the thickness of the outer oxide film gradually increased, and the aluminium content in M2O3 (M=aluminium and chromium) increased significantly, and with 5 % aluminium added, the aluminium oxide of the outer oxide film became the main body. [ABSTRACT FROM AUTHOR]

Die Vermeidung der Bildung equimolarer Mengen an Salzabfällen ist eine der größten Herausforderungen zur Nutzung von CO2 als C1 Baustein in C‐H‐Carboxylierungsreaktionen. Zur Lösung dieses Problems wurde ein zyklischer Prozess entwickelt, in welchem die industrielle Basischemikalie Dimethylsuccinat aus CO2 und Acetylen synthetisiert wird. Bei moderatem CO2‐Druck kann Acetylen mit Cäsiumcarbonat zweifach carboxyliert und das intermediäre Salz durch Hydrierung der C‐C‐Dreifachbindung stabilisiert werden. Bei 70 bar CO2 wird das Reaktionsmedium reversibel angesäuert, was die Veresterung des Carboxylatsalzes mit dem Lösemittel Methanol ermöglicht. Die Cäsiumbase und der Hydrierkatalysator können regeneriert und wiederverwendet werden. Dieses Reaktionskonzept eröffnet einen neuen Weg zur Umsetzung von Biogas (CH4/CO2) zu industriell relevanten C4 Basischemikalien. Der reversible Aziditätsswitch, die Rolle der Cäsiumbase so wie die des Lösungsmittelgemisches wurden durch thermodynamische Modellierung aufgeklärt. [ABSTRACT FROM AUTHOR]

Summary Most people underestimate the thermal energy that is required to heat up a cold garden pool. Such an underestimation is also often encountered in advertising where idealized or even unrealistic conditions are depicted. The most environmentally friendly option is the use of daily solar irradiation in combination with a thermal insulation of the pool bottom to avoid heat loss at night. All other options to heat up a pool at cold weather require a considerable amount of energy and are also associated with a considerable emission of carbon dioxide. It must also be considered that this heating process may occur even daily in a cool summer. This leads to a multiplication of the estimated costs for the family budget (in terms of Euros) and the environment (in terms of carbon dioxide). [ABSTRACT FROM AUTHOR]

During the deep-penetration welding of phosphorus deoxidized copper, a multitude of reactions occur which influence the formation of phases inside the welding region. Thereby, the microstructure evolution during laser beam welding depends on the chemical composition of the alloy as well as of the gaseous environment. As a result of reactions in a phosphorus rich copper melt, copper phosphides are formed which are located inside the grains as well as at the grain boundaries. Meanwhile, the formation of phosphorus pentoxide and an uncomplete decomposition of copper-I-oxide to elemental copper and phosphorus pentoxide were identified at the keyhole. Thereby, the decomposition of copper-I-oxide depends on the oxygen concentration. Thus, a complete decomposition of copper-I-oxide to elemental copper and phosphorus pentoxide was observed at the bottom side of the welding region due to a higher oxygen concentration. [ABSTRACT FROM AUTHOR]

Zusammenfassung Seit langer Zeit ist gut dokumentiert, dass die Photosynthese mit einem sehr geringen Wirkungsgrad von weniger als 3 % aus Sonnenlicht chemische Energie gewinnt. Aber warum ist der Prozess so ineffizient? Schließlich hatte die Photosynthese mehr als drei Milliarden Jahre in der Erdgeschichte Zeit, sich zu optimieren. Diese Frage wird hier mit dem geringen, aber thermodynamisch limitierten Gasaustausch zwischen Pflanzen und Atmosphäre erklärt. Während des Tages müssen Pflanzen der Atmosphäre Kohlendioxid entziehen, den Rohstoff für die Photosynthese. Dabei verlieren sie unvermeidbar große Mengen an Wasserdampf, verbunden mit ihrer Transpiration. Folglich sind Kohlendioxidaufnahme und Wasserdampfabgabe eng miteinander verbunden. Eine einfache Abschätzung zeigt, dass dieser Massenaustausch zwischen Erdoberfläche und Atmosphäre thermodynamisch limitiert ist. Sie kann die geringe Effizienz der Photosynthese schlüssig erklären. [ABSTRACT FROM AUTHOR]

In order to improve the properties of activated carbons in the separation of carbon dioxide/methane mixture, organic acid, namely acetic acid, is used to modify the commercial coconut shell activated carbons. The modified sample 15H‐AC shows greater adsorption capacity than the raw material. To further explore the adsorption mechanism of carbon dioxide and methane on 15H‐AC, adsorption kinetics and thermodynamics are studied and compared with that on R‐AC. According to the results of adsorption kinetic study, it can be observed that the diffusion of both carbon dioxide and methane on 15H‐AC is faster than that on the raw material. The findings obtained in the adsorption thermodynamics indicate that the interaction of both carbon dioxide and methane with the modified sample is stronger and the spontaneity degree is higher. The physical adsorption of carbon dioxide on 15H‐AC indicates that the regeneration of the adsorbents is easy. The modified activated carbon, which possesses higher adsorption capacity, faster adsorption rate and good reproducing property, is promising in the separation of carbon dioxide / methane gas mixtures industrially. [ABSTRACT FROM AUTHOR]

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Electroplating has been studied for centuries, not only in the laboratory but also in industry for machinery, electronics, automobile, aviation, and other fields. The lithium‐metal anode is the Holy Grail electrode because of its high energy density. But the recyclability of lithium‐metal batteries remains quite challenging. The essence of both conventional electroplating and lithium plating is the same, reduction of metal cations. Thus, industrial electroplating knowledge can be applied to revisit the electroplating process for lithium‐metal anodes. In conventional electroplating, some strategies like using additives, modifying substrates, applying pulse current, and agitating electrolyte have been explored to suppress dendrite growth. These methods are also effective in lithium‐metal anodes. Inspired by that, we revisit the fundamental electroplating theory for lithium‐metal anodes in this Minireview, mainly drawing attention to the theory of electroplating thermodynamics and kinetics. Analysis of essential differences between traditional electroplating and plating/stripping of lithium‐metal anodes is also presented. Thus, industrial electroplating knowledge can be applied to the electroplating process of lithium‐metal anodes to improve commercial lithium‐metal batteries and the study of lithium plating/stripping can further enrich the classical electroplating technique. [ABSTRACT FROM AUTHOR]

In the current study, nanostructured Cu−Zn−Al ternary alloy was synthesized via mechanical alloying. The structural evolutions were also measured using x‐ray diffraction and scanning electron microscope. The results showed an increase in lattice strain while the crystallite size decreased. Afterwards, thermodynamic analysis was carried out on Cu−Zn, Cu−Al and Zn−Al binary systems through Miedema's semi‐empirical model. It was found that in all binary systems, there is a driving force for solid solution formation over all compositions due to its negative Gibbs free energy changes in those compositions, whilst, this value is positive for the formation of amorphous phase over some compositions which can be attributed to the absence of driving force. Finally, the extended version of Miedema's semi‐empirical model was used and discussed in detail to determine the thermodynamic desirability of solid solution and amorphous phase formation for Cu−Zn−Al ternary system. It was concluded that in this ternary system, the minimum thermodynamic driving force for solid solution formation occurred for those compositions which were located in the corners of ternary diagram. [ABSTRACT FROM AUTHOR]

The Fröschnitz 1 and Fröschnitz 2 supply shafts of the Semmering Base Tunnel are used for the ventilation of the tunnel drives, transport of personnel, materials and machinery and as escape and rescue routes. Until the final completion of the concrete inner lining in the shafts, water still emerges repeatedly at the surface at a few locations of the shotcrete support layer. This led above all for the Fröschnitz 2 shaft to ice formation during longer periods with outside air temperatures below the freezing point of water with simultaneous operation of the fresh air supply. The effectiveness of warm air supply was investigated with thermodynamic and aerodynamic investigations and then the cost‐effectiveness of two selected systems to provide warm air were considered. The aerodynamic simulations showed that in particular the entry angle of the warm fresh air flow is decisive for the magnitude of the warm air losses. [ABSTRACT FROM AUTHOR]

It has been well-known that the addition of electrolytes causes the ionic surfactant solution to have a lower surface tension by stimulating the surface adsorption. When the surface concentration of an ionic surfactant remains constant, the solution with supporting electrolyte in the bulk displays a lower surface tension than a solution without electrolyte. From the surface perspective we investigate the dependence of the surface tension of a solution upon the surface concentration of ionic surfactant and the influences of the supporting electrolyte therein, by means of thermodynamics and molecular dynamics simulation. The derived thermodynamic formula and simulation results predict, that at a given surface concentration the supporting electrolyte can change the orientation of the ionic surfactant, which results in a lower surface tension. The conclusions can be useful for the investigation to the surface structure of ionic surfactant solutions and the effects of supporting electrolyte. [ABSTRACT FROM AUTHOR]

Efficient adsorptive separation of propylene/propane (C3H6/C3H8) is highly desired and challenging. Known strategies focus on either the thermodynamic or the kinetic mechanism. Here, we report an interesting reactivity of a metal–organic framework that improves thermodynamic and kinetic adsorption selectivity simultaneously. When the metal–organic framework is heated under oxygen flow, half of the soft methylene bridges of the organic ligands are selectively oxidized to form the more polar and rigid carbonyl bridges. Mixture breakthrough experiments showed drastic increase of C3H6/C3H8 selectivity from 1.5 to 15. For comparison, the C3H6/C3H8 selectivities of the best‐performing metal–organic frameworks Co‐MOF‐74 and KAUST‐7 were experimentally determined to be 6.5 and 12, respectively. Gas adsorption isotherms/kinetics, single‐crystal X‐ray diffraction, and computational simulations revealed that the oxidation gives additional guest recognition sites, which improve thermodynamic selectivity, and reduces the framework flexibility, which generate kinetic selectivity. [ABSTRACT FROM AUTHOR]

Insertionselektrochemische Elektroden zeichnen sich durch einen simultanen Übergang von Elektronen und Ionen aus, wobei beide Übergänge durch getrennte Grenzflächen erfolgen. Hier wird die Thermodynamik der Gesamtreaktion mit Rücksicht auf die Thermodynamik beider Übertragungsgleichgewichte diskutiert. Die Übersicht umfasst Systeme, bei denen die Redoxzentren in einer festen Phase sind und Ionen zwischen dieser Phase und der Lösung ausgetauscht werden, und auch Systeme, bei denen die Redoxzentren in einer flüssigen Phase gelöst sind und die Ionen zwischen dieser und einer zweiten, mit der ersten nicht mischbaren flüssigen Phase ausgetauscht werden. Dieser Kurzaufsatz verfolgt auch das Ziel, analoge Untersuchungen an Batteriematerialien zu initiieren, um deren Eigenschaften zu verbessern. Dreiphasenelektroden ermöglichen die Bestimmung der Freien Enthalpien des Elektronen‐ und Ionentransfers von Insertionselektroden. [ABSTRACT FROM AUTHOR]

Despite the importance of protein–surface interactions in both biology and biotechnology, our understanding of their origins is limited due to a paucity of experimental studies of the thermodynamics behind such interactions. In response, we have characterized the extent to which interaction with a chemically well‐defined macroscopic surface alters the stability of protein L. To do so, we site‐specifically attached a redox‐reporter‐modified protein variant to a hydroxy‐terminated monolayer on a gold surface and then used electrochemistry to monitor its guanidine denaturation and determine its folding free energy. Comparison with the free energy seen in solution indicates that interaction with this surface stabilizes the protein by 6 kJ mol−1, a value that is in good agreement with theoretical estimates of the entropic consequences of surface‐induced excluded volume effects, thus suggesting that chemically specific interactions with this surface (e.g., electrostatic interactions) are limited in magnitude. [ABSTRACT FROM AUTHOR]

In this paper, the adsorption process and kinetics of methylene blue onto the Yellow River bottom sediment was investigated. It was found that the equilibrium data fitted well to the Langmuir, Freundlich, Toth and Redlich‐Peterson model, with the Langmuir model showing the best fitting result compared to others. The adsorption process attained equilibrium within 60 min, and the adsorption capacity of Yellow River sediment increased with the increase in adsorbent concentration, temperature, and NaNO3 concentration. The adsorption capacity of the Yellow River sediment increases as the adsorbent pH decreases to a certain value and further decreasing the pH value can lead to decreasing adsorption capacity. Moreover, the presence of humic acid in natural concentration range had a minor influence on the adsorption quantity of the Yellow River sediment. Therefore, the Yellow River sediment, an easily available material, can be used for methylene blue removal in wastewater treatment processes. [ABSTRACT FROM AUTHOR]

Abstract: We present a method for the synthesis and precise size control of magnetic nanoparticles in a reversible magnetic agglomeration mechanism. In this approach, nanoparticles nucleate and grow until a critical susceptibility is reached, in which magnetic attraction overcomes dispersive forces, leading to agglomeration and precipitation. This phase change in the system arrests nanoparticle growth and gives true thermodynamic control over the size of nanoparticles. We then show that increasing the alkyl chain length of the surfactant, and hence increasing steric stabilization, allows nanoparticles to grow to larger sizes before agglomeration occurs. Therefore, simply by choosing the correct surfactant, the size and magnetic properties of iron nanoparticles can be tailored for a particular application. With the continuous addition of the precursor solution, we can repeat the steps of nucleation, growth, and magnetic agglomeration indefinitely, making the approach suitable for large scale syntheses. [ABSTRACT FROM AUTHOR]

Abstract: An important intermediate goal to evaluate our concept for the assumption‐free determination of single‐ion Gibbs transfer energies ΔtrG°(i, S1→S2) is presented. We executed the crucial steps a) and b) of the methodology, described in Part I of this treatise, exemplarily for Ag+ and Cl‐ with S1 being water and S2 being acetonitrile. The experiments showed that virtually all parts of the liquid junction potentials (LJPs) at both ends of a salt bridge cancel, if the bridge electrolyte is an “ideal” ionic liquid, that is, one with nearly identical diffusion of anion and cation. This ideality holds for [N2225]+[NTf2]‐ in the pure IL, but also in water and acetonitrile solution. Electromotive force measurements of solvation cells between S1 and S2 demonstrated Nernstian behavior for Ag+ concentration cells and constant like cell potentials for solutions with five tested Ag+ counterions. [ABSTRACT FROM AUTHOR]

Abstract: Described is a procedure for the thermodynamically rigorous, experimental determination of the Gibbs energy of transfer of single ions between solvents. The method is based on potential difference measurements between two electrochemical half cells with different solvents connected by an ideal ionic liquid salt bridge (ILSB). Discussed are the specific requirements for the IL with regard to the procedure, thus ensuring that the liquid junction potentials (LJP) at both ends of the ILSB are mostly canceled. The remaining parts of the LJPs can be determined by separate electromotive force measurements. No extra‐thermodynamic assumptions are necessary for this procedure. The accuracy of the measurements depends, amongst others, on the ideality of the IL used, as shown in our companion paper Part II. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, copper‐5 wt.%‐tin (Cu‐5wt%Sn) powder mixture was mechanically alloyed in order to study the solid solubility extension during the alloying process. Nanocrystalline supersaturated solid solution has been prepared in this system by high energy ball milling. Based on the thermodynamic model, the Gibbs free energy change in this alloy system during the formation of solid solution is calculated to be positive, which means that there is no driving force to form solid solution in copper‐tin (Cu−Sn) immiscible system. It has been found that a large fraction of grain boundaries and a high density of dislocations play a significant role in the solid solubility extension of immiscible copper and tin. [ABSTRACT FROM AUTHOR]

Many intrinsically disordered proteins (IDP) that fold upon binding retain conformational heterogeneity in IDP-target complexes. The thermodynamics of such fuzzy interactions is poorly understood. Herein we introduce a thermodynamic framework, based on analysis of ITC and CD spectroscopy data, that provides experimental descriptions of IDP association in terms of folding and binding contributions which can be predicted using sequence folding propensities and molecular modeling. We show how IDP can modulate the entropy and enthalpy by adapting their bound-state structural ensemble to achieve optimal binding. This is explained in terms of a free-energy landscape that provides the relationship between free-energy, sequence folding propensity, and disorder. The observed 'fuzzy' behavior is possible because of IDP flexibility and also because backbone and side-chain interactions are, to some extent, energetically decoupled allowing IDP to minimize energetically unfavorable folding. [ABSTRACT FROM AUTHOR]

A space-charge theory applicable to concentrated solid solutions (Poisson-Cahn theory) was applied to describe quantitatively as a function of temperature and oxygen partial pressure published data obtained by in situ X-ray photoelectron spectroscopy (XPS) for the concentration of Ce3+ (the reactive species) at the surface of the oxide catalyst Ce0.8Sm0.2O1.9. In contrast to previous theoretical treatments, these calculations clearly indicate that the surface is positively charged and compensated by an attendant negative space-charge zone. The high space-charge potential that develops at the surface (>0.8 V) is demonstrated to be hardly detectable by XPS measurements because of the short extent of the space-charge layer. This approach emphasizes the need to take into account defect interactions and to allow deviations from local charge neutrality when considering the surfaces of oxide catalysts. [ABSTRACT FROM AUTHOR]

Knowing the thermodynamic state of complex mixtures-liquid, gas, supercritical or two-phase-is essential to industrial chemical processes. Traditionally, phase diagrams are compiled piecemeal from individual measurements in a pressure-volume-temperature cell performed in series, where each point is subject to a long fluid equilibrium time. Herein, 1000 microfluidic chambers, each isolated by a liquid piston and set to a different pressure and temperature combination, provide the complete pressure-temperature phase diagram of a hydrocarbon mixture at once, including the thermodynamic phase envelope. Measurements closely match modeled values, with a standard deviation of 0.13 MPa between measurement and model for the dew and bubble point lines, and a difference of 0.04 MPa and 0.25 °C between measurement and model for the critical point. [ABSTRACT FROM AUTHOR]

The interaction of cresol red (CR) with cetylpyridinium bromide (CPB), sodium dodecyl sulphate (SDS), and Triton X-100 (TX-100) was studied in aqueous solutions employing conductometric, tensiometric, and spectroscopic methods. Various micellar and interfacial parameters were calculated in absence and in presence of CR. The interactions suggest the formation of a CR-CPB adduct, an association of CR with the micelle of TX-100 while no adduct is formed between CR and SDS. Appreciably low critical micelle concentration, CMC value of TX-100 compared with those of CPB and SDS in pure water and drastic reduction of CMC of CPB (about one-twelfth of its value in pure water) than SDS and TX-100 in the presence of CR were observed. Higher negative values of Gibbs free energy of micellization, ΔGm0, for all the three surfactants indicate that micellization process is spontaneous. The values of maximum surface excess concentration, Γmax, and minimum area per molecule, Amin, suggest that in the presence of CR, the air-solution interface is closely packed and the orientation of surfactant molecules is almost perpendicular to the surface. UV-visible spectra suggest the formation of ion-pair complex between the dye CR and the monomers of CPB in the pre-micellar region, while above the CMC a breaking up of the ion-pair complex takes place and the dye is solubilized in the micelles of CPB. In the case of SDS the absorption spectra indicate weak interaction between CR and SDS molecules formation of H-bonding, short range dispersive forces, and hydrophobic interactions between CR and TX-100 molecules in the solution. [ABSTRACT FROM AUTHOR]