Reversible state transition in nanoconfined aqueous solutions

Using molecular dynamics simulations, we find a reversible transition between the dispersion and aggregation states of solute molecules in aqueous solutions confined in nanoscale geometry, which is not observed in macroscopic systems. The nanoscale confinement also leads to a significant increase of the critical aggregation concentration (CAC). A theoretical model based on Gibbs free energy calculation is developed to describe the simulation results. It indicates that the reversible state transition is attributed to the low free energy barrier (of order kBT) in between two energy minima corresponding to the dispersion and aggregation states, and the enhancement of the CAC results from the fact that at lower concentrations the number of solute molecules is not large enough to allow the formation of a stable cluster in the confined systems.

The power of anticipated feedback: Effects on students' achievement goals and achievement emotions.

In an experimental study (N = 153 high school students), we tested a theoretical model positing that anticipated achievement feedback influences achievement goals and achievement emotions, and that achievement goals mediate the link between anticipated feedback and emotions. Participants were informed that they would receive self-referential feedback, normative feedback, or no feedback for their performance on a test. Subsequently, achievement goals and discrete achievement emotions regarding the test were assessed. Self-referential feedback had a positive influence on mastery goal adoption, whereas normative feedback had a positive influence on performance-approach and performance-avoidance goal adoption. Furthermore, feedback condition and achievement goals predicted test-related emotions (i.e., enjoyment, hope, pride, relief, anger, anxiety, hopelessness, and shame). Achievement goals were documented as significant mediators of the influence of feedback instruction on emotions, and mediation was observed for seven of the eight focal emotions. Implications for educational research and practice are discussed.

Power transfer in velocity-vortex acceleration

A theoretical model is presented of an electron acceleration-as-oscillator method derived from the work of Joseph Larmor unified with J. Clerk Maxwell’s theory of vorticity for the displacement of radiation into free-space at an antenna interface.

Risk aversion, overconfidence and private information as determinants of majority thresholds

We present and experimentally test a theoretical model of majority threshold determination as a function of voters’ risk preferences. The experimental results confirm the theoretical prediction of a positive correlation between the voter's risk aversion and the corresponding preferred majority threshold. Furthermore, the experimental results show that a voter's preferred majority threshold negatively relates to the voter's confidence about how others will vote. Moreover, in a treatment in which individuals receive a private signal about others’ voting behaviour, the confidence-related motivation of behaviour loses ground to the signal's strength.

Persuasive technology and users acceptance of e-commerce: users perceptions of website persuasiveness

Persuasive technologies have been extensively applied in the context of e-commerce for the purpose of marketing, enhancing system credibility, and motivating users to adopt the systems. Recognising that persuasion impacts on consumer behaviour to purchase online have not been investigated previously. This study reviews theories of technology acceptance, and identifies their limitation in not considering the effect of persuasive technologies when determining user online technology acceptance. The study proposes a theoretical model that considers the effect of persuasive technologies on consumer acceptance of e-commerce websites; with consideration of other related variables, i.e. trust and technological attributes. Moreover the paper proposes a model based on the UTAUT2, which contains relevant contributing factors; including the concept of perceived persuasiveness.

Insiders, outsiders, and the role of local enforcement in forest management: an example from Tanzania

In low-income countries, both nearby local villagers, “insiders”, and non-locals, “outsiders”, extract products from protected forests even though their actions are illegal. Forest managers typically combine enforcement and livelihood projects offered to nearby communities to reduce this illegal activity, but with limited budgets cannot deter all extraction. We develop a game theoretic model of a forest manager's decision interacting with the extraction decisions of insiders and outsiders. Our analysis suggests that, depending on the relative ecological damage caused by each group, budget-constrained forest managers may reduce total forest degradation by legalizing “insider” extraction in return for local villagers' involvement in enforcement activities against outsiders.

The effect of electric field direction on the-shear stress of ER fluids

The effect of the direction of external electric field on the shear stress of an ER fluid has been studied by molecular-dynamics simulation. Due to the formation of inclined chains, the shear stress strongly depends on the direction of the field, and it may be very large under some special field direction. And theoretical model of ideal microstructure of ER fluids has proved this result. Thus the ER effect may be greatly enhanced just by choosing an optimum direction for the field without any additional requirement, suggesting a promising way to the practical application of ER fluids.

The determinants of a cross market arbitrage opportunity: theory and evidence for the European bond market

This paper examines the determinants of cross-platform arbitrage profits. We develop a structural model that enables us to decompose the likelihood of an arbitrage opportunity into three distinct factors: the fixed cost to trade the opportunity, the level at which one of the platforms delays a price update and the impact of the order flow on the quoted prices (inventory and asymmetric information effects). We then investigate the predictions from the theoretical model for the European Bond market with the estimation of a probit model. Our main finding is that the results found in the empirical part corroborate strongly the predictions from the structural model. The event of a cross market arbitrage opportunity has a certain degree of predictability where an optimal ex ante scenario is represented by a low level of spreads on both platforms, a time of the day close to the end of trading hours and a high volume of trade.

Anisotropy of magnetoviscous effect in structure-forming ferrofluids

The magnetoviscous effect, change in viscosity with change in magnetic field strength, and the anisotropy of magnetoviscous effect, change in viscosity with orientation of magnetic field, have been a focus of interest since four decades. A satisfactory understanding of the microscopic origin of anisotropy of magnetoviscous effect in magnetic fluids is still a matter of debate and a field of intense research. Here, we present an extensive simulation study to understand the relation between the anisotropy of magnetoviscous effect and the underlying change in micro-structures of ferrofluids. Our results indicate that field-induced chain-like structures respond very differently depending on their orientation relative to the direction of an externally applied shear flow, which leads to a pronounced anisotropy of viscosity. In this work, we focus on three exemplary values of dipolar interaction strengths which correspond to weak, intermediate and strong interactions between dipolar colloidal particles. We compare our simulation results with an experimental study on cobalt-based ferrofluids as well as with an existing theoretical model called the chain model. A non-monotonic behaviour in the anisotropy of magnetoviscous effect is observed with increasing dipolar interaction strength and is explained in terms of micro-structure formation.

e-Leadership through strategic alignment: an empirical study of small and medium sized enterprises in the digital age

Small and medium sized enterprises (SMEs) play an important role in the European economy. A critical challenge faced by SME leaders, as a consequence of the continuing digital technology revolution, is how to optimally align business strategy with digital technology to fully leverage the potential offered by these technologies in pursuit of longevity and growth. There is a paucity of empirical research examining how e-leadership in SMEs drives successful alignment between business strategy and digital technology fostering longevity and growth. To address this gap, in this paper we develop an empirically derived e-leadership model. Initially we develop a theoretical model of e-leadership drawing on strategic alignment theory. This provides a theoretical foundation on how SMEs can harness digital technology in support of their business strategy enabling sustainable growth. An in-depth empirical study was undertaken interviewing 42 successful European SME leaders to validate, advance and substantiate our theoretically driven model. The outcome of the two stage process – inductive development of a theoretically driven e-leadership model and deductive advancement to develop a complete model through in-depth interviews with successful European SME leaders – is an e-leadership model with specific constructs fostering effective strategic alignment. The resulting diagnostic model enables SME decision makers to exercise effective e-leadership by creating productive alignment between business strategy and digital technology improving longevity and growth prospects.