Sensitivity of peak positions to flight-path parameters in a deep-inelastic scattering neutron TOF spectrometer

The effects of small changes in flight-path parameters (primary and secondary flight paths, detector angles), and of displacement of the sample along the beam axis away from its ideal position, are examined for an inelastic time-of-flight (TOF) neutron spectrometer, emphasising the deep-inelastic regime. The aim was to develop a rational basis for deciding what measured shifts in the positions of spectral peaks could be regarded as reliable in the light of the uncertainties in the calibrated flight-path parameters. Uncertainty in the length of the primary or secondary flight path has the least effect on the positions of the peaks of H, D and He, which are dominated by the accuracy of the calibration of the detector angles. This aspect of the calibration of a TOF spectrometer therefore demands close attention to achieve reliable outcomes where the position of the peaks is of significant scientific interest and is discussed in detail. The corresponding sensitivities of the position of peak of the Compton profile, J(y), to flight-path parameters and sample position are also examined, focusing on the comparability across experiments of results for H, D and He. We show that positioning the sample to within a few mm of the ideal position is required to ensure good comparability between experiments if data from detectors at high forward angles are to be reliably interpreted.

Formation of single-walled carbon nanotube via the interaction of graphene nanoribbons : ab initio density functional calculations

The interaction of bare graphene nanoribbons (GNRs) was investigated by ab initio density functional theory calculations with both the local density approximation (LDA) and the generalized gradient approximation (GGA). Remarkably, two bare 8-GNRs with zigzag-shaped edges are predicted to form an (8, 8) armchair single-wall carbon nanotube (SWCNT) without any obvious activation barrier. The formation of a (10, 0) zigzag SWCNT from two bare 10-GNRs with armchair-shaped edges has activation barriers of 0.23 and 0.61 eV for using the LDA and the revised PBE exchange correlation functional, respectively, Our results suggest a possible route to control the growth of specific types SWCNT via the interaction of GNRs.

Alcoholism and family interaction

In i6 families, half of which had an alcoholic parent, both parents and an adolescent were videotaped interacting with each other. Mothers, fathers and the adolescent in each family viewed the videotaped interaction and completed ratings of themselves and the other two family members on levels of anxiety, involvement, dominance and friendliness. In families with an alcoholic parent, adolescents and their mothers rated family members as less anxious than did adolescents and mothers in families without a drinking problem. Also mothers in the alcoholic families rated family members as being more involved, and their ratings were higher than mothers in other families. Alcoholic families rated parent-adolescent interactions as more dominant and friendlier. At least in these videotaped interactions where alcohol was not being consumed, mothers in alcoholic families adopted a more positive view of family members than mothers in other families. In addition, possibly due to the efforts of fathers not to drink and memories of interactions when he was drunk, alcoholic families perceived their family interactions as more dominant and friendlier than families without an alcohol-related problem. [Schweitzer R, Wilks j, Callan vJ. Alcoholism and family interaction.

Making Arrangements : Remote proposal sequences and attendant structural phenomena in social interaction

In this thesis, I contribute to the study of how arrangements are made in social interaction. Using conversation analysis, I examine a corpus of 375 telephone calls between employees and clients of three Community Home Care (CHC) service agencies in metropolitan Adelaide, South Australia. My analysis of the CHC data corpus draws upon existing empirical findings within conversation analysis in order to generate novel findings about how people make arrangements with one another, and some of the attendant considerations that parties to such an activity can engage in: Prospective informings as remote proposals for a future arrangement – Focusing on how employees make arrangements with clients, I show how the employees in the CHC data corpus use ‘prospective informings’ to detail a future course of action that will involve the recipient of that informing. These informings routinely occasion a double-paired sequence, where informers pursue a response to their informing. This pursuit often occurs even after recipients have provided an initial response. This practice for making arrangements has been previously described by Houtkoop (1987) as ‘remote proposing.’ I develop Houtkoop’s analysis to show how an informing of a future arrangement can be recompleted, with response solicitation, as a proposal that is contingent upon a recipient’s acceptance. Participants’ understanding of references to non-present third parties – In the process of making arrangements, references are routinely made to non-present third parties. In the CHC data corpus, these third parties are usually care workers. Prior research (e.g., Sacks & Schegloff, 1979; Schegloff, 1996b) explains how the use of ‘recognitional references’ (such as the bare name ‘Kerry’), conveys to recipients that they should be able to locate the referent from amongst their acquaintances. Conversely, the use of ‘non-recognitional references’ (such as the description ‘a lady called Kerry’), conveys that recipients are unacquainted with the referent. I examine instances where the selection of a recognitional or non-recognitional reference form is followed by a recipient initiating repair on that reference. My analysis provides further evidence thatthe existing analytic account of these references corresponds to the way in which participants themselves make sense of them. My analysis also advances an understanding of how repair can be used, by recipients, to indicate the inappositeness of a prior turn. Post-possible-completion accounts – In a case study of a problematic interaction, I examine a misunderstanding that is not resolved within the repair space, the usual defence of intersubjectivity in interaction (cf. Schegloff, 1992b). Rather, I explore how the source of trouble is addressed, outside of the sequence of its production, with a ‘post-possible-completion account.’ This account specifies the basis of a misunderstanding and yet, unlike repair, does so without occasioning a revised response to a trouble-source turn. By considering various aspects of making arrangements in social interaction, I highlight some of the rich order that underpins the maintenance of human relationships across time. In the concluding section of this thesis I review this order, while also discussing practical implications of this analysis for CHC practice.