Effect of pressure on the mechanical and dynamical stability of NaAlSi

The effects of pressure on the mechanical and dynamical stability of NaAlSi have been fully investigated by first-principles calculations within the generalised gradient approximation (GGA). The obtained results show that the optimised lattice constants, atomic positions and elastic constants at ambient pressure are in good agreement with the available experimental and theoretical data. The lattice constants decrease monotonically with increasing pressure. The elastic constant C₁₁, C₁₂, C₁₃, C₃₃ and C₆₆ increase while C₄₄ decreases with increasing pressure. It is found that NaAlSi is mechanically unstable when the pressure is above 25.97?GPa. The phonon-dispersion curves along several high symmetry lines are obtained. The phonon frequencies at the Z point decrease with increasing pressure and completely soften to zero at 27.52?GPa, further confirming the structural instability of NaAlSi.     

Teaching the Bible in the Context of General Education

Three conceptions of general education developed under the titles ‘general,’‘generalist,’ and ‘generalizing’ are matched with appropriate strategies for teaching the Bible. These provide the basis for two points relevant to teaching the Bible in colleges and universities: first, that the prime object of attention is not the Bible, but rather a corporate agreement regarding an educational project; and second, that the ways in which the Bible might be taught will vary, appropriately, according to the ways in which that educational enterprise is understood. A corollary is stated: teachers of the Bible need to be as informed about research in teaching as they are in biblical research.     

Case illustration: Moving along…and,is change gradual or sudden?

A sequence of analytic sessions of a professional woman in her forties is used to illustrate the moving along process. The material shows a gradual change, where the patient's experience of her sense of agency is altered through a particular kind of interactive sequence. The example is intended to make it clear that the group's view of how change occurs is not strictly or primarily in terms of sudden changes, and that the problem of assessing moments of meeting as well as quantitative and qualitative shifts is one with which the group continues to struggle. © 1998 Michigan Association for Infant Mental Health     

An Empirical Examination of Same- and Other-Gender Sexual Harassment in the Workplace

This study examines sexual harassment (SH) whichinvolves members of the same gender, either male orfemale. Data are taken from the 1988 Department ofDefense Survey of Sex Roles in the Active Duty Military. Separate comparisons for male (38% White, 31%Black, and 31% ‘other’) and female (48%White, 27% Black, and 25% ‘other’) targetsare made between sameand other-gender SH related to fourmajor components of a conceptual model proposed by Fitzgerald,Drasgow, Hulin, Gelfand, & Magley (1997). Thesecomponents include sexual harassment behaviors, personalvulnerability, target response styles, and consequences of the SH for the target. The sexualorientation of targets and perpetrators is notconsidered because data were unavailable. Results reveala number of meaningful differences between sameandother-gender SH. The most striking result is that maletargets of same-gender SH experience consequences thatare significantly more pervasive and severe than thoseexperienced by male targets of other-gender SH.Organizational implications are discussed.     

Modeling of 1-3 piezoelectric composites operating in thickness-stretch vibration mode

For bulk piezoelectric ceramics plates, the fundamental thickness-stretch (TSt) waves are always coupled to the in-plane extension waves and the symmetric thickness-shear waves. The occurrence of these spurious modes in bulk piezoelectric ceramics plates is undesirable as it may interfere with the operation of transducers. 1–3 piezoelectric composites are promising candidates to suppress the spurious modes mentioned above. However, theoretical modelling of multiphase ceramic composite objects is very complex. In this study, a simple analytical TSt vibration model is constructed from three-dimensional equations of linear piezoelectricity. The mechanical damping is considered in the model by introducing a complex elastic constant. The performance of 1–3 piezoelectric composites is analysed and the electrical impedance results from theoretical and experimental analysis are compared. The results show that there is excellent agreement between the experimental electrical impedance and that obtained by the theoretical TSt vibration analysis. This indicates that 1–3 piezoelectric composites can be operated in a nearly pure TSt vibration mode near the fundamental resonance. The analytical model we present is valid for analysing 1–3 piezoelectric composites plates with large aspect ratios quickly and efficiently.     

Direct comparison of episodic encoding and retrieval of words: an event-related fMRI study

Functional magnetic resonance imaging (fMRI) was used to compare directly episodic encoding and retrieval. During encoding, subjects studied visually presented words and reported via keypress whether each word represented a pleasant or unpleasant concept (intentional, deep encoding). During the retrieval phase, subjects indicated (via keypress) whether visually presented words had previously been studied. No reliable differences were found during the recognition phase for words that had been previously studied and those that had not been studied. Areas preferentially active during encoding (relative to retrieval) included left superior frontal cortex, medial frontal cortex, left superior temporal cortex, posterior cingulate, left parahippocampal gyrus, and left inferior frontal gyrus. Regions more active in retrieval than encoding included bilateral inferior parietal cortex, bilateral precuneus, right frontal polar cortex, right dorsolateral prefrontal cortex, and right inferior frontal/insular cortex.     

Feeding-based arousal effects on visual recognition memory in early infancy.

Arousal effects on a 1-trial visual recognition paired-comparison task were studied at newborn, 1-month, and 4-month test ages. Infants were tested before and after feeding, with arousal assumed to be lower after feeding. Newborns and 1-month-olds shifted from a familiarity preference before feeding to a novelty preference after feeding. A control group tested only after feeding confirmed that this shift was not due to increased stimulus exposure from the prefeeding test. By 4 months, infants showed novelty preferences independent of feeding. This age by arousal interaction for recognition memory extends previous knowledge by including endogenous arousal with age, stimulus, and length of exposure as contributors to familiarity-novelty preferences. It also extends and provides converging evidence for arousal effects on visual attention in early infancy found previously with preferential looking. A shift from subcortical to cortical dominance is supported.     

Dispositional and situational goal orientations as discriminators among recreational and competitive league athletes.

The present study examined the relationship between individual goal orientation, motivational team climate, perceived sport competence, and league structure among 216 youth soccer players. It was predicted that competitive league teams would report higher ego-involvement and performance-oriented team climate and lower sport competence than recreational teams. Discriminant analyses indicated that only the mastery-oriented team climate variable differentiated competitive and recreational teams. Athletes who participated in recreational teams reported a greater degree of mastery-oriented climate than competitive league players. The results suggest that athletes' perceptions of situational rather than dispositional aspects of achievement goals are more highly affected by the playing structure present in youth sport teams. The possible psychological benefits derived from the development of a mastery-oriented team climate in sports are discussed.     

The Role of Schools in Outcomes for Youth: Implications for Children's Mental Health Services Research

We explore the role of schools in children's mental health services research. Recent literature has suggested that schools play an important role in delivering services to children and adolescents with emotional and behavioral problems. Research in services research, though, has taken a fairly narrow view of which dimensions of school environments are relevant for inclusion in studies. We suggest that a broader view of school environments is appropriate and potentially beneficial to the field. Using Bronfenbrenner's ecological model as a guide, we conceptualize schools as microsystems. Such an approach suggests that all aspects of school environments (treatment as well as non-treatment) are likely to influence many of the outcomes that children's mental health services research frequently targets (e.g., behavioral problems, problematic peer relationships, academic achievement, school attendance). We review literature from a variety of disciplines to suggest relevant features of schools, with particular attention to the role of peer dynamics within schools. We conclude with implications of this expanded conceptualization of schools for children's mental health services research.     

New polytypes of long-period stacking ordered structures in a near-equilibrium Mg97Zn1Y2 alloy

By atomic-scale high-angle annular dark-field scanning transmission electron microscopy, the long-period stacking ordered (LPSO) structures in a near-equilibrium Mg₉₇Zn₁Y₂ (at.%) alloy have been characterised. In addition to 18R and 14H, new polytypes of LPSO structures are analysed and determined as 60R, 78R, 26H, 96R, 38H, 40H, 108H and 246R. All of these LPSO structures feature AB′C′A building blocks with two Mg layers and three Mg layers sandwiched between them. The Bravais lattices and space groups of new polytypes of LPSO structures were easily determined via the newly introduced method. A structural relationship between the LPSOs is proposed.