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The COVID-19 pandemic forced many teachers around the world to make a sudden switch from face-to-face to online teaching. This shift in practice has provided an opportunity to reconsider how technology use in mathematics education can be utilised to improve student engagement. In this study, we explore four case studies of Australian secondary mathematics classrooms conducted prior to the COVID-19 pandemic to examine how teachers are using blended learning approaches and how their students perceive these pedagogical practices. Findings across all four sites indicate that technology use expands student opportunities to engage with mathematics learning through the provision of multiple pathways and methods of access. Specifically, we find evidence supporting the use of blended classroom teaching strategies to provide differentiation and personalised learning approaches; visualisation and dynamic manipulation of mathematics concepts; and alternative methods for teacher-student feedback and communication. We argue that the student learning experience in mathematics can be enhanced through a variety of blended learning approaches by allowing for diverse points of access to learning opportunities which are more closely aligned to individual learning needs and free from the temporal constraints of the classroom. [ABSTRACT FROM AUTHOR]

This introductory article of the Special Issue themed Teachers as Designers of Instructional Tasks provides an overview of the research reported in the six articles of the issue. The articles show teachers playing a more active role in choosing and designing materials for their own instructional work thus illuminating new affordances in a number of fronts. We summarise these new utilities along the lines research, design, and professional development. [ABSTRACT FROM AUTHOR]

Aim: To determine the influence of erosive tooth wear in the primary dentition on parental perceptions of oral health. Methods: This cross-sectional study involved a standardised clinical examination of 775 preschool aged children and a parent-administered questionnaire. Erosive tooth wear was measured using the Basic Erosive Wear Examination Index. Results: 71% and 81% of 3 (n = 256) and 5 year-old children (n = 337) respectively exhibited signs of erosive tooth wear. Prevalence was influenced by region (p = 0.049) (p = 0.007) in both age cohorts (χ2, p < 0.05) respectively and by parental level of education (p = 0.012) in the 5-year-old cohort. Parental perception of oral health was significantly associated (χ2, p < 0.05) with parental level of education in the 5-year-old cohort and with the presence of dental caries, reports of pain and dental appearance of the child in both age cohorts. Parental perceptions were unaffected by the degree of erosive tooth wear their child exhibited (p = 0.0564), (p = 0.739) in both age cohorts respectively. Conclusions: Erosive dental tooth wear is increasingly observed in the primary dentition however is not perceived as an oral health issue by parents. Its diagnosis and management therefore, fall heavily within the remit of the dental practitioner. [ABSTRACT FROM AUTHOR]

Background: In Malta, off-label prescribing of medicines in children stands at 45%, mainly because of failure by prescribers to follow the dosing recommendations in the product literature. In addition, registration procedures of pharmaceuticals may inadvertently contribute to this high incidence of off-label prescribing. Methods: A literature review was conducted to identify regulatory provisions relating to the registration of medicines in Malta that could give rise to off-label use. Furthermore, the product literature of the 2 classes of medicines most commonly prescribed in children, antibiotics and respiratory medicines, were reviewed. This was done in order to gauge whether the different registration routes implemented in Malta to market these medicines could give rise to off-label use. Results: The national registration procedure relating to Article 126a of Directive 2001/83/EC and, to a lesser extent, line extensions, parallel importation, and the provision detailed in Article 11 of Directive 2001/83/EC were found to lead to discrepancies and potentially misleading inclusions in the product literature. These, in turn, may well contribute to off-label use of medicines in children. Conclusions: Off-label prescribing does not necessarily mean that efficacy and safety data are unavailable. Variances in the product literature of medicines having the same active ingredients but imported from different countries may cause divergent prescribing practices, leading to inadvertent off-label use. The various stakeholders, including member states such as Malta, should devise strategies to harmonize the most recent labeling information in order to support the safe and effective use of pediatric medicines, thereby decreasing off-label use. [ABSTRACT FROM AUTHOR]

Digital natives are now of age and comprise the new generation of early career teachers (ECTs). This is an important change in teacher demographics given that new technologies have been introduced into classrooms with expectations that teachers embed them effectively into the teaching of mathematics. This paper draws on the data of three separate studies and reanalyses it to explore how a small group of four early career primary school teachers use information and communication technologies (ICT) in their teaching of mathematics. Two of the ECTs were observed using interactive whiteboards in their mathematics teaching, and two were observed predominantly using tablets. Two important variables developed from the research presented in this paper suggest that ECT's uses of technology to teach mathematics may not be without complications. First, the teachers appeared to experience 'device conflict', in that the type of device and its particular affordances and limitations were the primary factors that influenced their mathematics. This was particularly evident in the uses of fixed and mobile devices. The interactive whiteboard (IWB) did not pose pedagogical challenges to the ECTs as their stable location facilitated the opportunity to still use these devices in traditional teaching ways. However, tablets did pose a problem because of their mobility and the need to reconfigure the organisation and to some extent the roles of teacher and student. The second finding was that the teachers' mathematical knowledge for teaching appeared to be directly related to the ways they used their technology. [ABSTRACT FROM AUTHOR]

This article is a report on a longitudinal case study that investigated the problem of lowered engagement with mathematics and students’ perspectives of the factors that influenced their engagement during the middle years of schooling. The article provides a synthesis of the entire study and a summary of its findings. In order to address the research question a group of 20 students from within the same school cohort participated in the study spanning three school years from their final year of primary school, to their second year of secondary school. Data was collected through interviews, focus group discussions, and classroom observations. A major finding of this study was that positive pedagogical relationships between teachers and their students must be developed as a foundation for sustained engagement. [ABSTRACT FROM AUTHOR]

The levels of engagement in mathematics experienced by students during the middle years of schooling (Years 5 to 8 in New South Wales) has been of concern in Australia for some years. Lowered engagement in school has been attributed to factors such as inappropriate teaching strategies, curricula that is unchallenging and irrelevant, and cultural and technological conditions that continue to evolve (Sullivan et al. Australian Journal of Education 53(2):176-191, 2009). There is currently a gap in this field of research in terms of a lack of longitudinal studies conducted in an Australian context that feature students' voices and their perceptions of mathematics teaching and learning during the middle years. As part of a qualitative longitudinal case study spanning 3 school years, 20 students in their final year of primary school (aged between 11 and 12 years) were asked to provide their views on mathematics teaching and learning. The aim of the study was to explore the students' perspectives of mathematics teaching and learning to discover pedagogies that engage the students. During focus group discussions and individual interviews the students discussed qualities of a "good" mathematics teacher and aspects of "good" lessons. These were found to resonate well with current Australian quality teaching frameworks. The findings of this study indicate that students in the middle years are critically aware of pedagogies that lead to engagement in mathematics, and existing standards and frameworks should be used as a starting point for quality teaching of mathematics. [ABSTRACT FROM AUTHOR]

Amiodarone, which has been used since 1967 as an antiarrhythmic drug, gives rise to a variety of cardiac and extracardiac adverse side-effects. Among these, pulmonary toxicity is considered the most frequent and serious extracardiac side-effect, since it may occur in various atypical forms and often limits the drug's clinical use. We encountered a 67-year-old white male patient with suspected amiodarone pneumonitis characterized by multiple lung nodules associated with pleural and pericardial effusion and peripheral neuropathy. Because differential diagnosis with pulmonary infectious diseases may be extremely difficult, the attending physician should therefore bear in mind the possibility of amiodarone pneumonitis whenever the drug is given. [ABSTRACT FROM AUTHOR]

Adhesive friction considering electrostatic interaction is an important problem in practical engineering. However, the friction mechanism considering electrostatic interaction and adhesion of elastoplastic materials on the contact interfaces remains poorly understood. A sliding friction model considering the van der Waals attraction, repulsive and electrostatic interactions is established in this work. The effect of charge density on the normal force, friction force, contact area and stress distribution is thoroughly investigated. And the repeated sliding friction process is also quantitatively analyzed. It is shown that adhesion enhances with the increase of surface charge density. Moreover, the contribution of electrostatic interaction to adhesion in the contact process is always greater than that to friction in the sliding friction process under the conditions studied. In the initial stage of friction, the friction will gradually increase and the normal force will gradually decrease. It is also found that a higher charge density results in a lower normal force in the friction process. Furthermore, the increase of charge density leads to a bigger contact diameter and the increased asymmetry of stress field, resulting in the increase of friction force, equivalent plastic strain and friction coefficient. In addition, both normal force and friction force arrive at a steady state after several repeated friction circles for elastoplastic materials, which is due to the fact that the contact diameter tends to be constant because of the accumulation of plastic deformation. This work reveals the contribution of electrostatic interaction to friction during adhesive sliding process and provides some insights into the adhesive friction problem considering electrostatic interaction. [ABSTRACT FROM AUTHOR]

The flow of shale oil in nano-scale rock pores follows the slip flow regime, in which the flow velocity at the nanopore walls is not zero. The nano-scale effect of the boundary layer renders the slip flow effect in the nanopores non-negligible. In this study, the slip flow mechanism of shale oil in nanopores was reviewed. The nano-scale effect of the boundary layer renders the slip flow effect in the nanopores non-negligible. The slip length and flow enhancement factor are the primary parameters used to evaluate the slip effect. The main factors influencing the slip effect were then analyzed, including the fluid properties, nanopore properties, pressure gradient, and temperature. Additionally, three slip flow models for shale oil in circular, elliptical and slit nanopores were reviewed. Moreover, a modification method for the shape factor is introduced to evaluate the slip effect of irregular nanopores. The general conclusions regarding the mechanism and models of slip flow in shale oil are summarized as follows: (1) Slip flow of shale oil occurs predominantly in nanopores due to scale effects and stronger internal interaction forces among alkane molecules. (2) The influence of slip flow is more pronounced in organic nanopores than in inorganic nanopores. (3) Significant slip flow effects are observed with larger slip lengths and flow enhancement factors. (4) Our analytical models indicated that slip flow effects are more pronounced with smaller hydraulic diameters. (5) The effects of slip flow are more pronounced in nanopores with irregular geometric shapes. Lastly, recommendations for future research are proposed. [ABSTRACT FROM AUTHOR]

The reference interaction site model (RISM) theory has been employed in the study of hard homonuclear and heteronuclear diatomic liquids. The RISM equation coupled with the Percus–Yevick and Martynov–Sarkisov closures has been solved numerically. The excess chemical potential has been computed using analytic expression based on correlation functions. An improved prediction of an excess chemical potential has been done with an interpolation scheme, which relates an excess chemical potential for hard-sphere fluid to that of tangent hard-sphere diatomic fluid at the same density. Our findings for an excess chemical potential for hard homonuclear fluid are compared with available accurate data. Maximum deviations of the excess chemical potential from the Percus–Yevick and Martynov–Sarkisov approximations are of 9.56 % and of 5.58 % , respectively. Some values of numerically obtained excess chemical potential for hard heteronuclear diatomic fluid present good comparison with available Monte Carlo data. To our knowledge, this is the first attempt to calculate an excess chemical potential for hard diatomic fluid in the Martynov–Sarkisov approximation. Moreover, radial distribution functions for hard-sphere, tangent hard homonuclear, and heteronuclear diatomic fluids from the Martynov-Sarkisov approximation are in good agreement with those in the literature. [ABSTRACT FROM AUTHOR]

To delve into the mechanisms of lubricating additives in electrically charged environments, this study utilizes a non-covalent modification method combining N-butylpyridinium tetrafluoroborate ([BPy]BF4) with multilayer graphene (MG) to create graphene/ionic liquid (G/IL) composites. These composites were tested as lubricating additives in polyalphaolefin 40 (PAO40) using the UMT-2 experimental platform to assess their performance and electrical regulation mechanisms. Results demonstrated that G/IL composites significantly enhance lubrication and electrical stability. The study discovered that varying the current's intensity and polarity substantially influences ion concentration and Zeta potential at the interface, reducing the electroviscous effect and facilitating the formation of an interfacial adsorption film. The interplay of these mechanisms greatly optimizes the interface condition. Additionally, real-time contact resistance data indicated a correlation between friction coefficient and contact resistance, validating the synergistic effect's impact. This research not only clarifies the complex action mechanisms of lubricating additives in charged conditions but also offers critical insights for designing highly efficient lubricating materials. [ABSTRACT FROM AUTHOR]

We suggest a new interpretation for pH-dependent temporal evolution in the microstructure and rheology of silica suspensions based on interparticle interactions, which differs from the conventional explanation including the catalytic effect of hydroxyl ions and charges. The temporal evolution of silica suspensions under various pH conditions was investigated through rheometry and diffusing wave spectroscopy (DWS) analysis. The transition from liquid to solid was observed to be the most rapid at pH 5 compared to other pH conditions (pH 3, 7, 9). This phenomenon could not be adequately explained by the conventional Derjaguin-Landau-Verwey-Overbeek (DLVO) theory that predicts the liquid-to-solid transition occurs more rapidly at the lower pH condition due to the lower surface charge. As an alternative, we employed an elaborated DLVO theory that additionally considers the hydration force, arising from the hydrophilic nature of the silica surface. The pH dependency was interpreted using the elaborated DLVO theory, which showed that the strong short-range nature of the hydration force significantly reduced the attraction range at pH 3, leading to the retardation and decline in structural and rheological development. The impact of pH and resulting alterations in interparticle interaction on the microstructure were further investigated using rheological scaling theory. [ABSTRACT FROM AUTHOR]

Dissipative structures often appear as an unstable counterpart of ordered structures owing to fluctuations that do not form a homogeneous phase. Even a multiphase mixture may simultaneously undergo one chemical reaction near equilibrium and another one that is far from equilibrium. Here, we observed in real time crystal seed formation and simultaneous nanocrystal aggregation proceeding from CeIV complexes to CeO2 nanoparticles in an acidic aqueous solution, and investigated the resultant hierarchical nanoarchitecture. The formed particles exhibited two very different size ranges, resulting in further pattern formation with opalescence. The hierarchically assembled structures in solutions were CeO2 colloids, viz. primary core clusters (1–3 nm) of crystalline ceria and secondary clusters (20–30 nm) assembled through surface ions. Such self-assembly is widespread in multi-component complex fluids, paradoxically moderating hierarchical reactions. Stability and instability are not only critical but also complementary for co-optimisation around the nearby free energy landscape prior to bifurcation. For atomically precise nanoparticle synthesis, it is crucial to understand hierarchical interactions during nanostructure formation. Here, the authors observe the crystal seed formation and simultaneous nanocrystal aggregation of ceria from aqueous solution in real time to understand hierarchically different intra- and interparticle interactions governing the particle shapes. [ABSTRACT FROM AUTHOR]

Nanofiltration (NF) and reverse osmosis (RO) processes are physical separation technologies used to remove contaminants from liquid streams by employing dense polymer-based membranes with nanometric voids that confine fluids at the nanoscale. At this level, physical properties such as solvent and solute permeabilities are intricately linked to molecular interactions. Initially, numerous studies focused on developing macroscopic transport models to gain insights into separation properties at the nanometer scale. However, continuum-based models have limitations in nanoconfined situations that can be overcome by force field molecular simulations. Continuum-based models heavily rely on bulk properties, often neglecting critical factors like liquid structuring, pore geometry, and molecular/chemical specifics. Molecular/mesoscale simulations, while encompassing these details, often face limitations in time and spatial scales. Therefore, achieving a comprehensive understanding of transport requires a synergistic integration of both approaches through a multiscale approach that effectively combines and merges both scales. This review aims to provide a comprehensive overview of the state-of-the-art in multiscale modeling of transport through NF/RO membranes, spanning from the nanoscale to continuum media. [ABSTRACT FROM AUTHOR]

Nanobubbles are an important means to enhance the flotation of fine refractory minerals. Generally, nanobubbles are preferentially adsorbed on mineral surfaces, which increases the hydrophobicity of the surfaces. For flake graphite ore, nanobubbles coated on graphite surfaces reduce the thickness of the hydrated film on the mineral surface and increase its hydrophobicity. In comparative experiments performed here, short flotation circuits of small flake graphite coated with nanobubbles achieved a 92.81% average fixed carbon grade of graphite concentrate, whereas conventional flotation circuits achieved an average of 88.15%. In addition, the concentrate recovery of short flotation circuits with nanobubbles was higher than that of conventional flotation circuits. This result shows that nanobubbles enhanced graphite particle flotation. Further, in this process, reducing the grinding duration is beneficial to avoid the overgrinding of concentrate, maintain the flake scale size of graphite, and improve the grade of the graphite concentrate. [ABSTRACT FROM AUTHOR]

The quantum corrections related to the ideal gas model often considered are those associated to the bosonic or fermionic nature of particles. However, in this work, other kinds of corrections related to the quantum nature of phase space are highlighted. These corrections are introduced as improvements in the expression of the partition function of an ideal gas. Then corrected thermodynamics properties of the ideal gas are deduced. Both the non-relativistic quantum and relativistic quantum cases are considered. It is shown that the corrections in the non-relativistic quantum case may be particularly useful to describe the deviation from the Maxwell–Boltzmann model at low temperature and/or in confined space. These corrections can be considered as including the description of quantum size and shape effects. For the relativistic quantum case, the corrections could be relevant for confined space and when the thermal energy of each particle is comparable to their rest energy. The corrections appear mainly as modifications in the thermodynamic equation of state and in the expressions of the partition function and thermodynamic functions like entropy, internal energy and free energy. Expressions corresponding to the Maxwell–Boltzmann model are shown to be asymptotic limits of the corrected expressions. [ABSTRACT FROM AUTHOR]

Adhesion is the attraction between dissimilar atoms of surfaces or particles, wherein a normal force is required to separate them. Various reasons for adhesion include electrostatic force, capillary force and hydrophobic force. Adhesion due to van der Waals force caused by the attraction between permanent or induced atomic/molecular dipoles has a special significance as it is always present. Adhesion plays a prominent role in the contact interactions at small scales, and understanding them is important in studies on the origin of friction and wear. The finite element method is employed to analyse adhesive contact, wherein the adhesive force is modelled as a body force derived from Lennard–Jones potential. Adhesive contact between an elastic cube (asperity) and the surface of a semi-infinite rigid body has been analysed using this approach. The numerical results obtained are compared with the analytical expressions for interaction free energy based on the idealized power-law forms proposed by Parsegian. [ABSTRACT FROM AUTHOR]

In this work, hardwood kraft lignin was oxidized with nitric acid to produce oxidized lignin (OL) with three different molecular weights of OL1 = 2600 g/mol, OL2 = 35,000 g/mol, and OL3 = 64,000 g/mol but with similar charge densities of − 1.8 to − 2.1 meq/g. Then, the coagulation efficiency of the lignin derivatives in aluminum oxide suspensions was studied fundamentally. The adsorption studies depicted that all three OLs had similar adsorption at a low dosage (< 2 mg/g). At higher dosage, because of its smaller size, OL1 adsorbed relatively more on the surface of the particles. Regardless of the molecular weight of OL, the highest reduction in relative turbidity did not occur at neutral zeta potential suggesting a patching mechanism of coagulation for particles. Generally, the coagulation happened at a low dosage of 0.4 mg/g, while the charge reversal and re-stabilization of particles dominated at a higher OL dosage. The coagulation studies revealed a similar coagulation affinity of lignin derivatives for the particles, which is ascribed to their similar charge densities. Also, the coagulation studies in a saline system depicted that the presence of salt improved the adsorption of OL on aluminum oxide particles due to the improvement in the hydrophobic-hydrophobic interactions between OL and particles. [ABSTRACT FROM AUTHOR]

Bubble technology has proven to be an efficient technique of reducing environmental pollution, strengthening water treatment procedures, and increasing production in industrial and agricultural applications. Compared to large bubbles such as macro- or micro-bubbles, nanobubbles (NBs) in liquids have several intriguing properties, including low buoyancy, high mass transfer efficiency, and high reactivity. In particular, NBs smaller than 200 nm are unexpectedly stable. However, determining the underlying mechanism of the stability of NBs in a solution is difficult. Most studies only focus on the temporal changes in the size and surface charge of NBs; the changes in the concentration of NBs are typically ignored. In this study, we investigate the number and stability of high-concentration NBs under various conditions. The results show that the number and concentration of NBs can be maintained at approximately 80–90% under various conditions, such as aging, temperature, centrifugation, shaking, and stirring. In other words, NBs possess significant potential for use in mass production and distribution in bubble technologies. [ABSTRACT FROM AUTHOR]

The interaction forces between silica surfaces with various degrees of hydrophobicity were measured using colloidal probe atomic force microscopy to clarify the relationship between the hydrophobicity of the surfaces and hydrophobic attraction in detail. The interaction forces between silica surfaces pre-hydrophobised with octadecyltrichlorosilane were measured in aqueous solutions with three different (cationic, anionic, and nonionic) surfactants. Hydrophobic attraction was observed between surfaces from 10 to 15 nm without surfactant, and the range of this attraction decreased when the surface hydrophobicity decreased with increasing surfactant concentration. The hydrophobic attraction disappeared when the surface contact angle was below 80°–90° in the presence of all surfactants used in this study. The range of the hydrophobic attraction was found to depend strongly on the contact angle and not on the surfactant type and concentration. The adhesion force was also highly dependent on the contact angle and comparable to the theoretical capillary force. The possible origin of this force is discussed with reference to the obtained results. [ABSTRACT FROM AUTHOR]

It is essential to secure the optical performance (sensitivity, FOM, plasmonic absorption strength, etc.), large-area fabrication, and physical durability to improve the usability of nanostructured SPR sensors. In this study, to ensure the physical durability of an Au-covered silica sphere monolayer (Au film over nanosphere (AuFON)) manufactured for use as an SPR sensor platform, the sensing performance and physical durability after TMOS treatment to bind spherical silica particles were investigated. The peel-off test showed that Au and silica constituting the AuFON did not fall off, and there was no significant difference in the sensing sensitivity and plasmonic absorption intensity before and after TMOS treatment. In addition, when colloidal Au nanoparticles (diameter of 5 nm) were applied to as-prepared AuFON and heat-treated, it was confirmed that the Au shells of the plasmonic particles were interconnected, and the Fano intensity increased from 3–5% to 22%. [ABSTRACT FROM AUTHOR]

Gibbs Ensemble Monte Carlo (GEMC) is a molecular simulation method commonly used for simulating phase equilibrium. This method has been proposed since 1987 and applied in many fields, such as geology, planetary science, chemical engineering, material science, etc. GEMC method combines canonical (NVT), isobaric-isothermal (NPT), and grand canonical (μVT) Monte Carlo techniques in a single simulation. The GEMC method was developed on the fundamental law of phase equilibrium that chemical potentials of each phase all equal. Two key factors affect the rationality and reliability of GEMC simulations: 1. particles can be efficiently moved in/out from certain phase during simulation; 2. samplings can represent the whole system well, in other words, samplings hold good ergodicity. In addition, various parallel methods have been developed to improve the simulation efficiency. In this review, an introduction to the theoretical fundamentals, improvements on particle movement and sampling protocols, acceleration techniques and some applications of the GEMC method will be presented. This is the first integrated review introducing the fundamentals, improvements and applications of the GEMC simulation method. [ABSTRACT FROM AUTHOR]

Colloid and colloid-facilitated solute transport have been identified as major environmental issues in the past few decades. Several field and laboratory-scale experiments have confirmed the rapid migration of radionuclides, heavy metals, pharmaceuticals, and pesticides adsorbed by colloids present in the subsurface aquifer system. This study deals with fundamental mechanisms of colloid mobilization and the principle mathematical relationship describing the various modifications of colloid transport like attachment–detachment, size exclusion, and air–water interfacial area. The effect of the size exclusion mechanism on the movement of colloids in the subsurface system is represented pictorially through a numerical model. In addition, the effect of surface potential and Hemakar constant on the interactions of colloidal particles are also elaborated. This article investigates the studies in this area through the bibliometric analysis of the articles extracted from the Scopus database from 1984 to 2021. The network and density distribution plots provide the recent development and trend of research in this field. The effect of water saturation and initial concentration of colloids attached to solid–water interface on release and mass recovery of colloidal particles under cycles of imbibition and drainage need to be interpreted experimentally. Numerical models considering attachment of mobile colloids at air–water interface and air–water–solid contact line under transient flow fields should be incorporated to study the complex migration characteristics of the colloidal particles present in the subsurface ecosystem during infiltration and water table fluctuations. Underestimating the rapid migration of contaminants attached to mobile colloids imparts potential risk of vadose zone and groundwater contamination. [ABSTRACT FROM AUTHOR]

Macroscopic thermodynamics, via the weak coupling approximation, assumes that the equilibrium properties of a system are not affected by interactions with its environment. However, this assumption may not hold for quantum systems, where the strength of interaction between the system and the environment may become non-negligible in a strong coupling regime. In such a regime, the equilibrium properties of the system depend on the interaction energy and the system state is no longer of the Gibbs form. Regarding such interactions, using tools from the quantum estimation theory, we derive the thermodynamic uncertainty relation between intensive and extensive variables valid at all coupling regimes through the generalized Gibbs ensemble. Where we demonstrate the lower bound on the uncertainty of intensive variables increases in presence of quantum fluctuations. Also, we calculate the general uncertainty relations for several ensembles to corroborate the literature results, thus showing the versatility of our method. [ABSTRACT FROM AUTHOR]

Proliferation of nanoparticles (NPs) as aqueous pollutants is a matter of growing concern today. The aggregation kinetics of colloidal bare silver (Ag, 20.5 nm) and silver iodide (AgI, 15.3 nm) NPs were investigated during ozone/ultraviolet (O3/UV) oxidation. Dynamic light scattering was applied to monitor the aggregation of NPs, and the z-average of treated samples was considered aggregate diameter. The effect of temperature, pH, and initial concentration of NPs was investigated on the aggregation rate constant and stability ratio. At a short oxidation period of approximately 1 min, the lower stability ratio was achieved for Ag NPs (< 50) than AgI NPs (> 100). Under acidic conditions, the negative surface charge of both NPs was neutralized that resulted in faster aggregation. In contrast, the impact of temperature and initial concentration of NPs on the aggregation rate was different for both NPs, which was due to the type of O3/UV interaction with the surface of NPs and the thickness of the electrical double layer surrounding the NPs. The aggregation behavior of Ag NPs obeyed diffusion-limited regime, while an intermediate regime between diffusion- and reaction-limited was observed for AgI NP aggregation. The resulting aggregate morphologies showed that the clusters were ramified for Ag and compressed for AgI NPs. Applying the O3/UV oxidation process for water treatment purposes leads to a significant reduction in aggregation time for inherently unstable Ag and stable AgI toxic NPs from several hours or days to several minutes. [ABSTRACT FROM AUTHOR]

In this study, the flow structure and efficacy of electrokinetic micromixer with rough walls is investigated using a numerical method. The main purpose is to use both active and passive methods of electrokinetic and wall roughness to further improve the performance of the micromixer. Surface roughness can be used to disrupt the flow and create perturbation and ultimately improve the performance of the micromixer. COMSOL Multiphysics 5.6 software is employed to simulate the problem. The effects of type of roughness geometry, direction of wall roughness, and electric field intensity on the mixing effectiveness of the proposed micromixer are analyzed. The results show that for the case of micromixer with the smooth walls, the mixing effectiveness parameter is only 53.4%, while by using the roughness on the walls, the mixing effectiveness parameter is improved considerably. The micromixer with the oblique-angled triangle roughness with the mixing effectiveness parameter of 73.7% has the best mixing effect among the other cases. For the case of roughness with non-equilateral triangle shape, the mixing effectiveness parameter increases significantly and is about 70.5%, and for the case of roughness with right-angled triangle shape, it is about 72.5%. The direction of wall roughness has negligible effect on the mixing effectiveness parameter. By using the roughness on the micromixer walls, the average velocity at the output of the micromixer is decreased. The mixing effectiveness parameter increases with decreasing the exerted electric field from 200 Volt/cm to 50 Volt/cm. For the case of micromixer with oblique-angled triangle roughness, there is no necessity to consider a lengthy channel and the effective length of the mixture is not long (almost 1500 μm). [ABSTRACT FROM AUTHOR]

With the synthesis of nanocar structures the idea of transporting energy and payloads on the surface became closer to reality. To eliminate the concern of diffusive surface motion of nanocars, in this study, we evaluate the motion of C60 and C60-based nanovehicles on graphene and hexagonal boron-nitride (BN) surfaces using molecular dynamics simulations and potential energy analysis. Utilizing the graphene-hBN hybrid substrate, it has been indicated that C60 is more stable on boron-nitride impurity regions in the hybrid substrate and an energy barrier restricts the motion to the boron-nitride impurity. Increasing the temperature causes the molecule to overcome the energy barrier frequently. A nanoroad of boron-nitride with graphene sideways is designed to confine the surface motion of C60 and nanovehicles at 300 K. As expected, the motion of all surface molecules is limited to the boron-nitride nanoroads. Although the motion is restricted to the boron-nitride nanoroad, the diffusive motion is still noticeable in lateral directions. To obtain the unidirectional motion for C60 and nanocars on the surface, a temperature gradient is applied to the surface. The unidirectional transport to the nanoroad regions with a lower temperature occurs in a short period of time due to the lower energies of molecules on the colder parts. [ABSTRACT FROM AUTHOR]

The energy crisis is one of the most emergency problems that humanity is facing now. To alleviate energy crisis, some new energy sources different from traditional fossil energy are developed in the past decades, for example, nuclear energy, wind energy, solar energy, et al. Among these new energy sources, an important energy existing in the ocean and river named as salinity gradient energy benefits from the features of green, safe, low cost and huge amount, and comes into the researcher's sight. In this article, we review the recent progress in harvesting salinity gradient energy with reverse electrodialysis (RED) membrane. First, the mechanism of RED was introduced, including the basic structure and working principle of RED, the ion selectivity, and the ion rectification effect. The materials which are suitable for RED were discussed in detail, such as 1D nanofluidic nanochannels, 2D materials, and composite materials. Among these materials, 2D materials are thought to be one kind of powerful material for RED because of the feasibility of producing ion-selective membranes. Besides, we dwell on the influences of solution conditions on the RED performance, like the salt gradient and species, pH value, and so on. Finally, we discussed what the RED membranes need in theory and experiment to satisfy the practical application. And the large-scale production and the anti-fouling for the long-term running of RED membranes are two key issues needed to be solved through the analysis of this paper. [ABSTRACT FROM AUTHOR]

Effects of residues produced by agricultural wastes fermentation (AWF) on low grade copper sulfide ores bioleaching, copper recovery, and microbial community were investigated. The results indicated that adding appropriate bulk of AWF made contributions to low grade copper sulfide ores bioleaching, which may be mainly realized through reducing the passivation layer formed by Fe3+ hydrolysis. Improved copper recovery (78.35%) and bacteria concentration (9.56 × 107 cells·mL−1) were yielded in the presence of 5 g·L−1 AWF. The result of 16S rDNA analysis demonstrated that microbial community was differentiated by adding AWF. Bacteria proportion, such as Acidithiobacillus ferrooxidans, Moraxella osloensis, and Lactobacillus acetotolerans changed distinctly. Great difference between samples was showed according to beta diversity index, and the maximum value reached 0.375. Acidithiobacillus ferrooxidans accounted for the highest proportion throughout the bioleaching process, and that of sample in the presence of 5 g·L−1 AWF reached 28.63%. The results should show reference to application of agricultural wastes and low grade copper sulfide ores. [ABSTRACT FROM AUTHOR]

In investigation of the aggregative stability of disperse systems by sediment volumetry, a violation of the structure of water in the contact area causes formation of nanobubbles, whose coalescence leads to appearance of hydrophobic attraction forces. A change in the aggregative stability of aqueous dispersions of particles can be interpreted in such a way that ingress of water molecules having a high potential of interaction with molecules of the medium in the interfacial gap between particle surfaces and outflow of water molecules exhibiting high intensity of interaction with a solid surface from the interfacial gap between particle surfaces is difficult. Excess osmotic pressure between hydrophilic surfaces leads to their hydrophilic repulsion, and excess osmotic pressure of the surrounding water (reduced osmotic pressure between surfaces) leads to hydrophobic attraction of the surfaces. To change the result of flotation, it is sufficient to bring a heat flow to a nanoscale-thick liquid layer, within which action of forces of structural origin is localized, determining the stability of wetting films. To increase the temperature in the interfacial gap between the particle and the bubble using the heat of water vapor condensation, as a gas for flotation, a mixture of air and hot water vapor is proposed. The developed flotation method has been tested in flotation of gold ores. The efficient steam flow rate determined from the results of a factorial experiment is 10.7 × 10–3 kg/(s m2), with the xanthate flow rate being 1.74 g/t. In the rough flotation operation, the jet method of constructing a flowsheet is used, which provides for combination of the initial feed and rough concentrate. In comparison with flotation of ores according to a factory scheme, the yield of a concentrate sent to hydrometallurgical processing is smaller by 23.4 rel. %, with the achieved level of gold recovery remaining the same. [ABSTRACT FROM AUTHOR]

Citrus black spot (CBS), caused by the fungus Phyllosticta citricarpa, is associated with serious yield and quality losses. The climate suitability of the Mediterranean Basin for CBS development has been long debated. However, CBS has been described in Tunisia. In this study, a generic model was used to simulate potential infections by ascospores and pycnidiospores together with a degree-day model to predict the onset of ascospore release. High-resolution climatic data were retrieved from the ERA5-Land dataset for the citrus-growing regions in the Mediterranean Basin and other locations where CBS is present. In general, the onset of ascospore release was predicted to occur late in spring, but there is no agreement on the adequacy of this empirical model for extrapolation to the Mediterranean Basin. The generic model indicated that infections by ascospores and pycnidiospores would be concentrated mainly in autumn, as well as in spring for pycnidiospores. In contrast to previous studies, the percentage of hours suitable for infection was higher for pycnidiospores than for ascospores. The values obtained with the generic infection model for Tunisia and several CBS-affected locations worldwide were similar to those for other citrus-growing regions in Europe and Northern Africa. These results support previous work indicating that the climate of the Mediterranean Basin is suitable for CBS development. [ABSTRACT FROM AUTHOR]

The current study focuses on non-equilibrium molecular dynamics (NEMD) simulations to investigate the slip properties of water flowing over different nanostructured surfaces. A simulation protocol is developed that applies constant shear stress throughout the fluid before measuring the slip length. Using pseudo-data, the reliability of this protocol in terms of both accuracy and noise of the results for high-slip and multiphase systems is demonstrated. In contrast to the NEMD techniques available in the literature, the protocol also enables a convenient way to compare the slip lengths of different surface coatings. The fluid slip lengths of surface coatings comprising carbon nanotubes on platinum are predicted using the proposed protocol with nitrogen gas trapped in the interstitial gaps. The role of these gas pockets in determining surface slip properties is investigated. The NEMD results from the proposed model compare well with a macroscopic theoretical model for nano-patterned surfaces. Finally, it is concluded that entrapped gas within nanostructures may offer significant drag reduction only if the gas surface coverage is above 95%. [ABSTRACT FROM AUTHOR]

Definitions of the equilibrium surface tension (ST) existing in thermodynamics are analyzed along with reasons for their ambiguity. A molecular statistical analysis of the concept of equilibrium ST at the vapor–liquid interface is given and a procedure for calculating it within the simplest microscopic model of statistical physics (the lattice gas model) is formulated. Equilibrium ST is shown to be a mechanical characteristic calculated under the condition of a rigorous phase equilibrium over three partial equilibria (mechanical, energy, and chemical). Violation of the chemical equilibrium results in non-equilibrium ST. The emergence of metastable STs is due to the artificial introduction of a foreign film boundary into the model through the Laplace equation, which distorts the real properties of the system. Means of statistical physics for obtaining existing definitions of equilibrium ST in the theory of integral equations for fluids and molecular dynamics are discussed along with a criterion for distinguishing between equilibrium and non-equilibrium STs, metastable and otherwise. Analysis shows that none of the current means of statistical physics ensures correct calculations of equilibrium STs with regard to all molecular features of the considered systems. [ABSTRACT FROM AUTHOR]

Whether grain boundaries (GBs) premelt is a longstanding question, because of the difficulty of direct experimental tests. Here, we focused an optical beam to locally heat single GBs within bulk hard-sphere colloidal crystals, observing the melting dynamics at single-particle resolution by video microscopy. The melting point is determined by analysing both the Lindemann parameter and the critical nucleus size for homogeneous nucleation. We found that all the GBs, including the high-energy GBs, can be superheated and melt via a heterogeneous nucleation mechanism. Based on the classical nucleation theory of GBs, we measured the incubation time and contact angle of the critical nucleus to compute all relevant kinetic factors, as well as the energy barrier, nucleation rate and the diffusion coefficient at the solid–liquid interface under weak superheating. The superheat limits of GBs with various misorientations have also been measured to further explore the instability mechanism. Under traditional uniform heating, premelting occurs only at triple junctions, whereas GBs retain their original structures up to the melting point. The premelted regions at triple junctions further interrupt high-energy GBs from superheating, through intrusion by uniform liquid layers. Overall, our experiments confirm the existence of superheating of GBs. Understanding the dynamics of grain boundaries and their melting behaviour is important for controlling the mechanical properties of materials. Now, experiments show that grain boundaries can be superheated, and that they melt via a nucleation mechanism. [ABSTRACT FROM AUTHOR]

Lubricant-infused surfaces hold promise to reduce the huge frictional drag that slows down the flow of fluids at microscales. We show that infused Teflon wrinkled surfaces induce an effective slip length 50 times larger than expected based on the presence of the lubricant alone. This effect is particularly striking as it occurs even when the infused lubricant's viscosity is several times higher than that of the flowing liquid. Crucially, the slip length increases with increasing air content in the water but is much higher than expected even in degassed and plain Milli-Q water. Imaging directly the immersed interface using a mapping technique based on atomic force microscopy meniscus force measurements reveals that the mechanism responsible for this huge slip is the nucleation of surface nanobubbles. Using a numerical model and the height and distribution of these surface nanobubbles, we can quantitatively explain the large fluid slip observed in these surfaces. Why are lubricant-infused surfaces so effective at reducing drag in microfluidic flow? Here, authors reveal that infused nanostructured Teflon wrinkles induce large interfacial slip due to the spontaneous nucleation of surface nanobubbles, a mechanism likely to occur on most rough infused surfaces. [ABSTRACT FROM AUTHOR]

The friction peak that occurs in tire-road sliding when the contact changes from wet to dry was previously attributed to capillary cohesion, van der Waals attraction, and surface roughness, but the detailed mechanisms have yet to be revealed. In this study, friction and static contact experiments were conducted using a custom-built in situ optical microtribometer, which allowed us to investigate the evolution of the friction, normal load, and contact area between a polydimethylsiloxane (PDMS) film and a silicon nitride ball during water volatilization. The friction coefficient increased by 100%, and the normal force dropped by 30% relative to those in the dry condition during the wet-to-dry transition. In static contact experiments, the probe indentation depth increased, and the normal load decreased by ∼60% as the water evaporated. Combining the friction and static contact results, we propose that the large friction peak that appeared in this study can be attributed to the combined effects of increased adhesive capillary force and increased plowing during the wet-to-dry transition. [ABSTRACT FROM AUTHOR]

The < 900-m-thick Paleogene carbonates of the Maltese Islands and offshore wells comprise 16 facies grouped into 7 carbonate facies associations (TA, TB, TC, TD1, TD2, TE1 and TE2). Previous works misclassified facies as belonging to a carbonate ramp, which derailed hydrocarbon exploration. This study confirms that the 200-km-wide, flat-topped, Malta isolated carbonate platform consists of coarse-grained, platform margin sediments surrounding the muddy, shallow marine interior that was tectonically segmented by half graben during foreland extension. Dating by correlation to benthic foraminiferal zones reveals two > 15 Ma-long depositional hiatuses that bound the Eocene carbonates. Cyclic sediments are capped by Eocene gypsum beds and Oligocene palaeosols and were controlled by third-order sea level cycles. About 700 m of inner platform sediments accumulated from the Eocene (TA and TB) to the early Chattian (TC) until an abrupt and ubiquitous change to platform margin facies dominated by coralline red algae and subordinate corals (TD1). The succeeding transgressive rhodalgal biostrome (TD2) aggraded > 40 m and prograded into underfilled half graben, later capped by mobile dunes of large benthic foraminifera (TE1). Deeper water oligophotic to aphotic biota (TE2) draped over the platform by the late Chattian. Increased foreland subsidence and the spread of coarse-grained platform margin sediments signals the beginning of the drowning succession reflecting environmental stress, the decline of coral reef builders, reduced sedimentation rate and increased dispersal rates, culminating in hardgrounds along the drowning surface that terminated carbonate platform sedimentation by the end of the Chattian. [ABSTRACT FROM AUTHOR]

As predicted by classical macroscopic theory, the lifetime for nanoscale gas bubbles is extremely short. However, stable gas nanobubbles have been experimentally observed in recent years. In this report, we theoretically show that, if the inner density of gas bubbles is sufficiently high, the lifetime of nanobubbles can increase by at least 4 orders of magnitude, and even approaches the timescale for experimental observations. [ABSTRACT FROM AUTHOR]

The interaction of Nafion polymer membrane with different amino acids has been experimentally investigated using photoluminescence spectroscopy. Experiments were performed with NaCl physiological solutions based on natural water (with a deuterium content of 157 ± 1 ppm) or on deuterium-depleted water (DDW) (deuterium content ≤1 ppm). This study was motivated by the fact that Nafion swelling in natural water is accompanied by "unwinding" of polymer fibers into the liquid bulk, whereas no unwinding occurs in DDW. In addition, the set of polymer fibers unwound into the liquid bulk is similar to the extracellular matrix (glycocalix) on a cellular membrane surface. It is of interest to analyze the role of unwound fibers in the interaction of amino acids with the polymer membrane surface. The interaction of amino acids with the membrane surface was found to induce luminescence quenching. We observed for the first time different dynamic modes arising during Nafion membrane swelling in a suspension of amino acids with different isotopic compositions, including trigger effects similar to the processes occurring in logic gates of computers. [ABSTRACT FROM AUTHOR]

Sticking of some elements of microelectromechanical systems is a serious problem, which may arise at the stages of producing or exploiting such devices. The equilibrium distances and adhesion energies between surfaces with a normal distribution of roughness have been studied with the purpose of controlling this process. Characteristics of the studied materials, such as dielectric functions, roughness, and plasticity, which are necessary for the calculations, have been discussed. The basic force balance equation has been briefly described. Detailed calculations have been performed for a Si–Au system in air. It has been shown that the plastic properties of gold very weakly affect the adhesion energy as a function of the interfacial distance; however, they markedly influence the establishment of the equilibrium distance. The long-range dispersion forces dominate in the adhesion energy at a roughness with a root-mean-square deviation of larger than 1 nm; therefore, the energy can be calculated within the framework of the Lifshits theory. [ABSTRACT FROM AUTHOR]

In electrochemical devices, such as batteries, traditional electric double layer (EDL) theory holds that cations in the cathode/electrolyte interface will be repelled during charging, leaving a large amount of free solvents. This promotes the continuous anodic decomposition of the electrolyte, leading to a limited operation voltage and cycle life of the devices. In this work, we design a new EDL structure with adaptive and passivating properties. It is enabled by adding functional anionic additives in the electrolyte, which can selectively bind with cations and free solvents, forming unique cation-rich and branch-chain like supramolecular polymer structures with high electrochemical stability in the EDL inner layer. Due to this design, the anodic decomposition of ether-based electrolytes is significantly suppressed in the high voltage cathodes and the battery shows outstanding performances such as super-fast charging/discharging and ultra-low temperature applications, which is extremely hard in conventional electrolyte design principle. This unconventional EDL structure breaks the inherent perception of the classical EDL rearrangement mechanism and greatly improve electrochemical performances of the device. Developing an electrolyte that is compatible with both high-voltage cathodes and Li metal anodes has always been challenging. Here, the authors created a new strategy by engineering a passivating electric double layer to achieve a fast-charging and lowtemperature high voltage lithium metal batteries. [ABSTRACT FROM AUTHOR]

Microfabricated chip-edge microcantilevers are commonly used as surface probes, e.g. in near-field microscopy. Such probes normally function in the low-deflection regime, where their behaviour is very well understood and documented. In contrast, when microcantilevers are used for applications such as electrical testing probes, their deflection can be somewhat higher, taking them into the less well understood high-deflection regime of microelectromechanical systems (MEMS). Here, a scalable model for the relationship between the skate, overtravel, and resulting tip contact force in tilted triangular cantilevers—which are bending with high deflection and in contact with a flat surface—is presented. The model is tested experimentally using macroscopic triangular cantilevers—the experimental results agree well with the proposed model. The findings enable a practical solution for zero-skate in tapered MEMS probes to be suggested. It is hoped that the findings may be of use for probe engineers involved with on-wafer testing and designers of emerging MEMS micro cantilever-based probes. [ABSTRACT FROM AUTHOR]

By means of an original technique, two dynamic effects at the interface, viscoelasticity and spreading, were considered. The first effect was studied with the help of a new interfacial rheometer via measuring the time and frequency dependences of the complex dynamic modulus for polymer solutions. The second effect was analyzed by examining the features of spreading of a multicomponent drop (solution or emulsion) onto interface. The obtained results were discussed with using the majority of relevant scientific publications. [ABSTRACT FROM AUTHOR]