Experimental determination and molecular dynamics simulation of specific heat for high temperature undercooled liquid

The accurate data of specific heat are of great significance in the thermodynamic analysis of phase transformation. Here, we report the experimental and calculated specific heat of liquid Ni_90.1Si_9.9 alloy by electromagnetic levitation drop calorimeter and molecular dynamics calculation, respectively. The experimental result, 39.54 J mol^?1 K^?1, is in good agreement with the calculated value of 38.03 J mol^?1 K^?1, and there exists only a little difference between them. The calculated undercooling range of 0 ～ 623 K is much wider than the experimental range of 0 ～ 218 K. The undercooled liquid structure of this alloy is analyzed according to the total and partial pair distribution functions, which show that the in-order degree of atom distribution enhances from normal liquid to undercooled liquid. The Si atoms are homogeneously dispersed among the Ni atoms, whereas the average distance among Ni atoms changes little.     

Simulation of surface effects on the intrinsic dissipation of nanooscillators

The rapid increase of surface area-volume ratio (SVR) with shrinking structure size has a great impact on surface-related intrinsic dissipation, which usually leads to low quality factors for the devices composed of nanoelectromechanical systems. In the present study, the flexural oscillations of nanocantilevers with varying thicknesses and lengths were simulated using the molecular dynamics method, in which the surface effects on the energy dissipation was evaluated when SVR was increased to extremely large values (between 0.4 and 2.0 nm^?1). And, it is also interesting to note that the prediction of the size-dependent Young's modulus by means of resonant frequency of the underdamped oscillation showed good agreement with previous findings.     

Dielectric and thermodynamic behaviour of binary mixtures of anisole with o-chlorophenol and with o-cresol

The molecular interactions in binary mixtures of anisole with o-chlorophenol and o-cresol have been studied at three different temperatures using dielectric measurements. The static permittivity and the permittivity at optical frequency have also been determined and used to obtain the Kirkwood correlation factors, the Bruggeman parameter, the excess permittivity and the excess free energy for different concentrations of two binary mixtures, namely (1) anisole + o-chlorophenol and (2) anisole + o-cresol. Using the effective Kirkwood correlation factor, parallel and anti-parallel alignments among the dipoles are identified. The corrective Kirkwood correlation factor, the excess permittivity and the Bruggeman parameter are used to explain the interaction between unlike molecules. The temperature dependences of the above parameters are also reported. The investigation shows systematic changes in the dielectric behaviour with variations in concentration and temperature.     

Site preference of refractory elements in γ′-Ni3Al alloyed with Ru

The influence of ruthenium (Ru) on the partitioning behavior of W, Re and Cr in γ′-Ni₃Al has been studied using the Dmol3 method based on the density functional theory. The calculated results show that W, Re and Cr have a preference for the Ni site in γ′-Ni₃Al alloyed with Ru. When Ru substitutes the central Ni atom, the site preference for W, Re and Cr varies. Furthermore, an electronic structure analysis of the alloy in terms of the Mulliken population and partial density of states was performed to elucidate the alloying mechanism of Ru in γ′-Ni₃Al. The results show that the strengthening effect of Ru in the alloy arises from a reduction in the binding energy of Ru as well as p-orbital hybridization between Ru and the host atoms.     

Deformation twins induced by multi-mode deformation in nanocrystalline copper

A multi-mode deformation model is used in a molecular dynamics simulation of nanocrystalline copper. Abundant deformation twin lamellae are developed by shearing the following compression to the elastic limit. Deformation twins (DTs) nucleate through two different mechanisms facilitated by Shockley partial slips. Interactions between DTs and Shockley partials are observed in this simulation.     

Molecular dynamics simulations of the size effect of titanium single-crystal nanopillars orientated for double prismatic slips

An inverse “smaller is stronger” trend is predicted on the basis of molecular dynamics simulations of α-titanium (Ti) single-crystal nanopillars orientated for double prismatic slips when the nanopillars are less than 7?nm wide. This trend is attributed to a significant increase in the surface energy due to the nucleation and propagation of edge dislocations on the surface of the pillars.     

Personality,Parental, and Media Influences on Aggressive Personality and Violent Crime in Young Adults

Debate remains regarding the interaction between predictor variables for aggression, including family environment, media violence, and personality. The current study examined the contributions of gender and personality, exposure to physical abuse and violence in the family, and exposure to media violence in both television and in video games on violent criminal activity. Data from young adults (n = 355) indicated that personality characteristics and direct physical abuse significantly predicted violent crime. Exposure to television and video game violence were not significant predictors of violent crime. These results elucidate the complex interplay between multiple factors related to the etiology of violent crime. These results also call into question the belief that media violence is involved in the etiology of violent crime.     

Much Ado About Something: An Ethic of the Common Good for Information Technology

As the culture of information technology grows and with it the exacerbation of associated problems, so does the body of literature that seeks to reflect on its impact and prospects. The advancements in information technology tend to be outpacing critical reflection and solid ethical analysis. The quality of the foundational ethical work done in information technology ethics has been inadequate, consisting of applied ethics or an appeal to law. This article considers how the richer perspective—the common good, as expressed through the lens of the Roman Catholic Church—can serve as a hermeneutic in the field of information technology ethics, offering a more substantial foundation to address pressing controversial issues associated with this burgeoning field and function as a guide for future developments in this industry. The common good can supplement the operative ways of appealing to law and business ethics to address crime and abuse associated with the World Wide Web with a specifically Roman Catholic paradigm and, in turn, offer a broader and richer appreciation of the societal-wide context that information technology impacts.     

The Influence of Mode of Test Administration on Test Performance

This study examined the influence of mode of test administration (paper based or computer-based) on anxiety levels and test performance. Participants were 44 learners (males = 22, females = 22) from three schools in Johannesburg, South Africa who completed both a computer and paper version of the Differential Aptitude Test—Form K Non-Verbal Reasoning test, the Computer Attitude Scale, the Computer Anxiety Rating Scale and Sarason's Test Anxiety Scale. Test anxiety was significantly related to both computer and paper based testing.