Formation of ω -Al7Cu2Fe phase during laser processing of quasicrystal-forming Al–Cu–Fe alloy

The formation of an ω-Al₇Cu₂Fe phase during laser cladding of quasicrystal-forming Al₆₅Cu_23.3Fe_11.7 alloy on a pure aluminium substrate is reported. This phase is found to nucleate at the periphery of primary icosahedral-phase particles. A large number of ω-phase particles form an envelope around the icosahedral phase. On the outer side, they form an interface with an α-Al solid solution. Detailed transmission electron microscopic observations show that the ω phase exhibits an orientation relationship with the icosahedral phase. Analysis of experimental results suggests that the ω phase forms by precipitation on an icosahedral phase by heterogeneous nucleation and grows into the aluminium-rich melt until supersaturation is exhausted. The microstructural observations are explained in terms of available models of phase transformations.     

Effect of mechanical stress on the absorption band tail of cubic boron nitride thin films synthesized by inductively coupled radio-frequency plasma chemical vapour deposition

Thin films of cubic boron nitride were deposited on silica and Si substrates by inductively coupled radio-frequency plasma chemical vapour deposition (IPCVD) technique using a B₂H₆?+?N₂?+?Ar gas mixture. Cubic phase formation was confirmed by glancing-angle X-ray diffraction studies, which showed reflections up to (311). Fourier-transform infrared (FTIR) spectra also indicated the predominantly cubic nature of the deposited films. The optical properties of the films were studied in the wavelength range 200–1000?nm. Both direct and indirect transitions were found to be present. Mechanical stress in the grain-boundary region of the films seems to contribute significantly to the optical absorption below the band gap. The intercrystalline barrier height (E _b) and the trap state density (Q _t ) were obtained from an analysis of the effects of grain boundaries on the optical properties of the samples.     

Estimation of the Coefficient of Variation with Minimum Risk: A Sequential Method for Minimizing Sampling Error and Study Cost

The coefficient of variation is an effect size measure with many potential uses in psychology and related disciplines. We propose a general theory for a sequential estimation of the population coefficient of variation that considers both the sampling error and the study cost, importantly without specific distributional assumptions. Fixed sample size planning methods, commonly used in psychology and related fields, cannot simultaneously minimize both the sampling error and the study cost. The sequential procedure we develop is the first sequential sampling procedure developed for estimating the coefficient of variation. We first present a method of planning a pilot sample size after the research goals are specified by the researcher. Then, after collecting a sample size as large as the estimated pilot sample size, a check is performed to assess whether the conditions necessary to stop the data collection have been satisfied. If not an additional observation is collected and the check is performed again. This process continues, sequentially, until a stopping rule involving a risk function is satisfied. Our method ensures that the sampling error and the study costs are considered simultaneously so that the cost is not higher than necessary for the tolerable sampling error. We also demonstrate a variety of properties of the distribution of the final sample size for five different distributions under a variety of conditions with a Monte Carlo simulation study. In addition, we provide freely available functions via the MBESS package in R to implement the methods discussed.     

On the short-range order in Al-Mn quasicrystals during low-temperature ageing

Abstract

We report the evolution of diffuse intensity during the low-temperature ageing of Al-Mn quasicrystals. This is taken as evidence of short-range order in the icosahedral phase prior to its decomposition. The implication of these diffuse intensities is discussed     

Orthorhombic approximant phases and their relation to quasicrystals in mechanically alloyed Al–Cu–Fe–Si alloys

The possibility of synthesis of quasicrystalline and associated approximant phases during mechanical alloying and subsequent heat treatment of Al₆₅Cu₂₀Fe₁₀Si₅ alloy powders has been investigated. It is shown that, in addition to the stable ordered quasicrystal and 1/1 cubic approximant, two more phases having orthorhombic symmetry coexist. The a and c parameters of both these phases are similar to the lattice parameters of the cubic approximant, whereas their b parameters are, respectively, three and four times larger than the c parameters. It is suggested that these phases evolve on account of local symmetry breaking of the cubic approximant phase, possibly due to ordering.     

Hearing Voices: The Impact of Announcer Speech Characteristics on Consumer Response to Broadcast Advertising

Virtually every broadcast advertisement uses the voice of an announcer, but due to lack of guidance from the marketing literature, managers must rely on gut feel when choosing a voice. Drawing on research from psycholinguistics, we identify 3 important voice characteristics —syllable speed, interphrase pausation, and pitch — and link these characteristics to key advertising response variables. By considering these 3 variables simultaneously, we test competing explanations previously offered to explain the process by which speech rate affects consumer response to advertising. Specifically, we assess whether an increase in speech rate enhances or reduces processing of the advertisement and whether this effect is driven primarily by syllable speed or interphrase pausation. Consideration of these 2 aspects of speech rate independently helps identify whether the changes in processing stem from changes in the opportunity to process and/or the motivation to process. Our results show that a voice with faster‐than‐normal syllable speed and low pitch produces less negative advertisement‐directed cognitive responses and more favorable ad attitudes, as well as more favorable brand attitudes, lending support to a motivational process explanation. No significant effects were found for interphrase pausation, suggesting that the results cannot be accounted for by the reduced opportunity to process in the compressed conditions.     

Shared dialect group identity,leader–member exchange and self‐disclosure in vertical dyads: Do members react similarly?

Drawing upon social identity and status characteristic theories, we examine the reactions of vertical dyad members to shared dialect group identity in Taiwan. Supervisors and subordinates in 179 vertical dyads independently reported their dialect group identity and their perceptions of leader–member exchange (LMX) and self‐disclosure. Results indicate that subordinates reported a more positive LMX with, and greater self‐disclosure to, supervisors who shared their dialect group identity. Supervisors reported greater self‐disclosure to subordinates with the same dialect group identity, but not a more positive LMX. We also discuss implications for organizational demography theory and research.     

Evolution of superlattice order in Al–Mn quasicrystals and its relation to face-centred icosahedral quasicrystals

Abstract

We have established a simple icosahedral to face-centred icosahedral ordering transformation in Al–Mn quasicrystals. This result strongly supports the view that the recently discovered face-centred icosahedral quasicrystal in ternary Al–Cu–Fe and related alloys represents a long-range superstructure of simple icosahedral quasicrystals     

Unconscious creativity: When can unconscious thought outperform conscious thought?

Recent research suggests that unconscious thought is superior to conscious thought in many cognitive domains. In this article, we show that the duration of unconscious thought has an inverted-U shaped relationship with creativity performance. Unconscious thought is, thus, unlikely to provide creative advantage over conscious thought when deliberation duration is either short or long. However, when deliberation duration is of a moderate length, the creative output of unconscious thought surpasses that of conscious thought. Furthermore, the superiority of unconscious thought pertains only to the novelty dimension of creativity, but not the appropriateness dimension. These findings not only shed light on the powers and limits of unconscious thought but also illuminate the importance of calibration in utilizing unconscious thought to boost creativity.     

Valuing time: Moderate download times can improve online goal pursuit

This research examines how the length of time for which a goal is interrupted affects goal pursuit, in an online context. Goal interruption duration in the form of long download time duration has been identified as a significant impediment to electronic commerce. It is believed that a faster download time is always better to motivate web users to keep surfing. We challenge this belief. In three studies, we find that, under certain circumstances, longer rather than shorter download times motivate web users to keep surfing longer. The counterintuitive pattern of effects can be explained by web users' fit experiences (Higgins, 2000) while surfing. In particular, our findings suggest that when online surfing “feels right”, web users think that online information is right.