Complexity and uncertainty often animate the desire for regulatory approaches seeking to fix, limit and constrain. But what if, instead of doubling down on ‘solid’ regulation, we also make room for ‘liquid’ regulatory approaches? We interrogate this question through deep empirical analysis of the developing regulatory framework around a form of Melanesian cultural property known as water music. We argue that, although both solid and liquid regulatory forms exist in all normative orders, we have recently seen an increasing emphasis on solid forms of regulation (legislation, registers, etc.) with respect to cultural property. As an effort to consider alternative approaches, we identify a range of liquid regulatory strategies drawing from our case-study. We show how attention to temporality, relationality and situatedness can impact upon the degree of liquidity of individual regulatory approaches, and how they can cumulatively impact the solidity or liquidity of the overall regulatory system. Finally, we identify the different ways in which gendered power and forms of accountability emerge in contexts of solid or liquid regulatory strategies.

The analysis presented in Part I of this study on the binary collision of equal molten calcium–magnesium–alumino–silicate (CMAS) droplets is extended to investigate the flow and interfacial dynamics of unequal CMAS droplet collision. Numerical investigations of head-on, off-center, and grazing collisions of two CMAS droplets of size 1 and 2 mm are conducted at pressure and temperature of 20 atm and 1548 K, respectively, that are representative of a gas-turbine combustor. At these conditions, the physical properties of CMAS are density, ρCMAS = 2690 kg/m3, surface tension between CMAS/air, σCMAS = 0.40 N/m, and viscosity, μCMAS = 11.0 N-s/m2. The primary difference between the CMAS and a fictitious fluid with viscosity 1/10 of CMAS was higher deformation for the lower viscosity case, leading to stretching and subsequent breakup of the liquid structure. These mechanisms are supported by the time evolution of surface, kinetic, and viscous dissipation energies.

This study focuses on binary droplet collisions of equal calcium–magnesium–aluminosilicate (CMAS) droplets formed by the melting of dust and sand ingested by gas turbine engines. Head-on, off-center, and grazing collision of 1 mm CMAS droplets traveling toward each other at a relative velocity of 100 m/s are numerically investigated using a volume-of-fluid-based direct numerical simulation approach at operating pressure and temperature of 20 atm and 1548 K, respectively. It is found that head-on and off-center collisions lead to droplet coalescence, whereas stretching behavior is observed for the grazing configuration. To elucidate the effect of viscosity, a fictitious fluid with all properties the same as CMAS except for viscosity (1/10 of CMAS) is also studied. It is found that the lower viscosity liquid deforms significantly as compared to CMAS for the head-on and off-center cases. These differences are quantified using the budgets of kinetic, surface, and dissipation energies. This paper represents the first study of its kind on the binary collision of CMAS droplets.

A liquid-state pyroelectric energy harvester is described and a remarkable capacity to convert a thermal gradient into electrical energy is demonstrated.

Increasing the sustainability of energy generation can be pursued by harvesting extremely low enthalpy sources: low temperature differences between cold and hot reservoirs are easily achieved in every industrial process, both at large and small scales, in plants as well as in small appliances, vehicles, natural environments, and human bodies. This paper presents the assessment and efficiency estimate of a liquid-state pyroelectric energy harvester, based on a colloid containing barium titanate nanoparticles and ferrofluid as a stabilizer. The liquid is set in motion by an external pump to control velocity, in a range similar to the one achieved by Rayleigh–Bénard convection, and the colloid reservoir is heated. The colloid is injected into a Fluorinated Ethylene Propylene pipe where titanium electrodes are placed to collect electrical charges generated by pyroelectricity on the surface of the nanoparticles, reaching 22.4% of the ideal Carnot efficiency of a thermal machine working on the same temperature drop. The maximum extracted electrical power per unit of volume is above 7 mW/m3 with a ΔT between electrodes of 3.9 K.

While fast-switching rewritable nonvolatile memory units based on phase-change materials (PCMs) are already in production at major technology companies such as Intel (16–64 GB chips are currently available), an in-depth understanding of the physical factors that determine their success is still lacking. Recently, we have argued for a liquid-phase metal-to-semiconductor transition (M-SC), located not far below the melting point, Tm, as essential. The M-SC is itself a consequence of atomic rearrangements that are involved in a fragile-to-strong viscosity transition that controls both the speed of crystallization and the stabilization of the semiconducting state. Here, we review past work and introduce a new parameter, the “metallicity” (inverse of the average Pauling electronegativity of a multicomponent alloy). When Tm-scaled temperatures of known M-SCs of Group IV, V, and VI alloys are plotted against their metallicities, the curvilinear plot leads directly to the composition zone of all known PCMs and the temperature interval below Tm, where the transition should occur. The metallicity concept could provide guidance for tailoring PCMs.

Recently, gel polymer electrolytes (GPEs) have been drawn noteworthy attention for different applications, specifically, for supercapacitors. GPEs could become an excellent substitute to liquid electrolytes (LEs) for making flexible and more durable devices. The performance of two different electrolytes (GPEs and LEs) in multi-wall carbon nanotube based supercapacitors were investigated. In spite of significantly lower conductivity of GPEs than LEs, devices with the gel electrolyte presented a superior performance. More focused has been given in this work on demonstrating the performance of supercapacitors based on GPEs and LEs at different concentrations of the acids ranging from 1M to 3M. Both electrolytes have been characterized at room temperature by making supercapacitors and using cyclic voltammetry, charging-discharging, electrochemical impedance spectroscopy, and leakage tests. The experimental results showed that GPE devices had much better capacitances and resistances compare to the LE based devices. Moreover, the capacitances of all devices were increased proportionally with the increase in the concentration from 1M to 3M, and the resistances were increased inversely with the decreased of concentration. The promising results from the gel electrolytes is encouraging for further development of flexible and high capacitance energy storage devices.

The erosion behavior of a directionally solidified Fe–B alloy containing 3.5 wt% B in the different velocities of flowing liquid zinc is investigated by X-ray diffraction and scanning electron microscopy to clarify the effect of interaction between Fe2B and the erosion products on erosion performance using a rotating-disk technique. The results indicate that the Fe–B alloy erodes at a low and steady rate in flowing liquid zinc. The microstructure of erosion layers of the directionally solidified Fe–B alloy depends on the orientation relation between the growth direction of Fe2B phase and the erosion surface. When the growth direction of Fe2B is perpendicular to the erosion surface, the Fe2B and the erosion compounds form a compact and stable combining layer that effectively inhibits the erosion of flowing liquid zinc and further improves the erosion resistance of Fe–B alloy.

This issue of MRS Bulletin focuses on materials that enable nanofluidic systems with unusually high mass fluxes, termed “enhancement factor” or “slip flow.” There is now ample evidence of such flow enhancement in nanochannels, with sizes ranging from subnanometer to a few nanometers. Most of the studies to date, both experimental and modeling, have focused on carbon nanotubes and, more recently, on graphene. Different fabrication methods result in different structures, surface chemistries, and defects, with a significant effect on flow enhancement. As new one-dimensional and two-dimensional nanomaterials are synthesized, a deeper understanding of the nanoscale transport physics is needed, particularly in the relationship between material properties and flow behavior. Herein, authors at the forefront of experimental, modeling, and theoretical developments in nanofluidic flow describe the state of the art in materials development and characterization.

Cold atmospheric pressure plasma has been intensively studied due to growing interest in biomedical applications. For example, it has been revealed that the plasma-irradiated cell culture medium (PAM: Plasma Activated Medium) shows antitumor effect as well as the direct plasma treatment. Long-lived reactive oxygen and nitrogen species (RONS), such as hydrogen peroxide (H2O2), nitrite (NO2-), and nitrate (NO3-), are considered as a main product in PAM. Therefore, investigation of the production characteristics of RONS in PAM with different experimental parameters is important. Here, we focused on humidification of feed gas (argon or helium) and effect of gap between the nozzle of the plasma jet and liquid surface. As a result, H2O2 concentration was increased by humidification of both feed gases. However, the concentration of NO2- and NO3- was decreased by the humidification of helium. In addition, the remarkable effect of the humidification on H2O2 production was observed when the plasma jet was in contact with the liquid surface.

In recent years, an increasing number of studies utilizing in situ liquid and/or gaseous cell scanning/transmission electron microscopy (S/TEM) have been reported. Because of the difficulty in the preparation of suitable specimens, these environmental S/TEM studies have been generally limited to studies of nanoscale structured materials such as nanoparticles, nanowires, or sputtered thin films. In this paper, we present two methodologies which have been developed to facilitate the preparation of electron-transparent samples from conventional bulk metals and alloys for in situ liquid/gaseous cell S/TEM experiments. These methods take advantage of combining sequential electrochemical jet polishing followed by focused ion beam extraction techniques to create large electron-transparent areas for site-specific observation. As an example, we illustrate the application of this methodology for the preparation of in situ specimens from a cold-rolled Type 304 austenitic stainless steel sample, which was subsequently examined in both 1 atm of air as well as fully immersed in a H2O environment in the S/TEM followed by hyperspectral imaging. These preparation techniques can be successfully applied as a general procedure for a wide range of metals and alloys, and are suitable for a variety of in situ analytical S/TEM studies in both aqueous and gaseous environments.

Transmission electron microscopy is a powerful technique for the analysis of solid samples, but it can also be used to image in liquid environments, gaining a unique view of processes and structures in liquids. Here, we describe recent developments in electron microscopy of liquids and discuss applications in several areas. We first describe closed-liquid-cell microscopy with its opportunities for visualizing electrochemical processes. We then discuss imaging of low-vapor-pressure liquids relevant to the operation of rechargeable batteries. Finally, we describe imaging of thick biological materials to obtain information on membrane proteins in intact mammalian cells that cannot be observed classically under dry or frozen conditions. Electron microscopy in liquid environments is developing rapidly and has the potential to solve key problems in materials science, physics, chemistry, and biology.

The tin–bismuth eutectic alloy possesses anomalous physicochemical properties that are dependent on temperature. This paper reports the interfacial reaction and growth behavior of the intermetallic compound (IMC) layer during the dissolution of solid copper in liquid eutectic tin–bismuth at 673–823 K under the influence of the structural transition of liquid eutectic tin–bismuth. The structural transition markedly affected the dissolution rate constant of solid copper and the growth rate of the IMCs. Correspondingly, the application of the liquid structural transition significantly decreased the activation energy of dissolution and increased the apparent activation energy for IMC growth. Moreover, two major roles of elemental Bi on the formation and growth of the IMCs were suggested.

We discuss recent literature data on the relaxation times (the primary tα), viscosity, and self-diffusion in water-glycerol and water-methanol mixtures across a wide temperature range from the stable water phase to the deep supercooled regime (373–147K). In particular, to clarify the role of hydrophilicity interactions (the hydrogen bonds) and hydrophobic interactions we study the mixture in terms of the water molar fraction (XW) with fixed temperatures at 5K steps across the entire composition range, and we find a marked deviation from the ideal thermodynamic behavior of the transport functions. This deviation is strongly T and XW dependent and spans values that range from two orders of magnitude at the highest temperature to more than five in the deeply supercooled regime (more precisely, at ≃200K). We analyze these deviations in terms of how the measured values differ from ideal values and find that the hydrogen-bonding water network dominates system properties up to XW = 0.3. We also examine an Arrhenius plot of the maximum excess value (Δtα(T) vs. 1/T) and find two significant changes due to water: one at the dynamical crossover temperature (TL ≃ 225K, i.e., the locus of the Widom line), and one at T ≃ 315K (the water isothermal compressibility χT minimum).

Recently, commercial home electric appliances with bactericidal/viral inactivation function of room air have been widely available. Most of these home appliances equip discharge devices which possibly generate reactive oxygen and nitrogen oxides. However, these effects are still controversial problem. To elucidate the inactivation effect of these devices at molecular level, we have been considering large DNA molecules as a biomarker to be used. By exposing DNA solution to the gas containing the chemical species, oxidative damage to DNA such as strand breaks can be induced. We have conducted the single-molecule-based evaluation method of DNA strand break using large linear DNA molecules. The obtained breakage rate could possibly be used for evaluation of reactivity of radicals generated by the discharge devices.

We performed dynamical cluster analysis in a Cu-Zr-Al based glass-forming metallic liquid using an unsupervised machine learning algorithm. The size of the dynamical clusters is used to quantify the onset of cooperative dynamics as the underlying mechanism leading to the Arrhenius dynamic crossover in transport coefficients of the metallic liquid. This technique is useful to directly visualize dynamical clusters and quantify their sizes upon cooling. We demonstrate the robustness of this algorithm by performing sensitivity analysis against two key parameters: number of mobility groups and inconsistency coefficient of the hierarchical cluster tree. The results elucidate the optimized range of values for both of these parameters that capture the underlying physical picture of increasing cooperative dynamics appropriately.

We explore the impact of monovalent counter-ions on the molecular conformation of highly charged flexible polyelectrolytes for a range of molecular topologies (linear chains, stars, and unknotted and trefoil rings) by molecular dynamics simulations that include an explicit solvent having short range interaction with the polyelectrolyte. In particular, we investigate how the counter-ions near the polyelectrolytes with variable mass influence the average molecular shape. We also characterize the interfacially “bound” counter-ions by calculating the time-averaged number of interfacial counter-ions, as well as the degree to which the polyelectrolytes wrap around the counter-ions by calculating the number of contacts between the counter-ions and the polyelectrolyte.

We demonstrate quantitative core-loss electron energy-loss spectroscopy of iron oxide nanoparticles and imaging resolution of Ag nanoparticles in liquid down to 0.24 nm, in both transmission and scanning transmission modes, in a novel, monolithic liquid cell developed for the transmission electron microscope (TEM). At typical SiN membrane thicknesses of 50 nm the liquid-layer thickness has a maximum change of only 30 nm for the entire TEM viewing area of 200×200 µm.

Data on a viscous flow model based on network defects – broken bonds termed configurons – were analysed. An universal equation has been derived for the variable activation energy of viscous flow Q(T) of the generic Frenkel equation of viscosity η(T)=A∙exp(Q/RT) which is known to have two constant asymptotes – high QH at low temperatures and low QL at high temperatures. The defect model of flow used by e.g. Doremus, Mott, Nemilov, Sanditov states that higher the concentration of defects (e.g. configurons) the lower the viscosity. We have used the configuron percolation theory (CPT) which treats glass–liquid transition as a percolation-type phase transition. Additionally the CPT results in a continuous temperature relationship for viscosity valid for both glassy and liquid amorphous materials. We show that a particular result of CPT is the universal temperature relationship for the activation energy of viscous flow: Q(T)=QL+RT∙ln[1+exp(-Sd/R) exp((QH-QL)/RT)] which depends on asymptotic energies QL (for the liquid phase) and QH (for the glassy phase), and on entropy of configurons Sd. This equation has two asymptotes, namely Q(T<<Tg) = QH, and Q(T>>Tg) = QL. Moreover we demonstrate that the equation for Q(T) practically coincides in the transition range of temperatures with known Sanditov equation.

Three methacrylic polymers bearing (phenylene)azobenzene moieties in the side-chain were synthesized via free-radical polymerization of monomer (E)-6-(4-((3’-cyano-4’-(hexyloxy) -[1,1’- biphenyl]-4-yl) diazenyl) phenoxy) hexyl methacrylate using 1, 5 and 10 mol% of 1,1’-azobis(cyclohexanecarbonitrile) (ABCN) as initiator. The chemical structures of monomer and polymers were confirmed by 1H NMR and FT-IR spectroscopies. Analysis by gel permeation chromatography (GPC) showed average molecular weights (Mw) of 1.0x105, 7.3x104, and 4.5x104 g/mol for polymers P1%, P5%, and P10%, respectively. These results indicate a clear dependence of the Mw on the amount of initiator used; the higher the amount of ABCN, the lowest the molecular mass. Thermotropic liquid-crystalline properties were analyzed by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). All polymers showed a liquid-crystalline behavior over a wide range of temperatures (>100°C) displaying smectic type mesophases. A small shift (around 8°C) upwards in the clearing temperature was observed on increasing the molecular masses from P10% to P1%. The trans-cis photo-isomerization of polymers was studied in solution and in thin films by UV-Vis spectroscopy. High cis-isomer contents in solution (>90%) were reached in relative short irradiation times.

We present a theoretical approach for modeling electrolyte solutions at interfaces that reaches into the mesoscale while retaining molecular detail. The total Hamiltonian of the system includes interactions arising from density and charge density (ion correlation) fluctuations, direct Coulomb interactions between ions, and at interfaces the image interactions, ion-solid and ion-water dispersion interactions. The model was validated against its ability to reproduce ion activity in 1:1 and 2:1 electrolyte solutions in the 0-2 M concentration range, its ability to capture the ion-specific effect in 1:1 electrolytes at the air-water interface, and solvent structure in a confined environment between hydrophobic surfaces, revealing the central role of ion hydration interactions in specific ion thermodynamic properties in the bulk solutions and at interfaces. The model is readily extensible to treat electrolyte interactions and forces across charged solid-water interfaces.