Influence of the sonication temperature on the debundling kinetics of carbon nanotubes in Propan-2-ol

The effect of sonication temperature on the debundling of carbon nanotube (CNT) macro-bundles is reported and demonstrated by analysis with different particle sizing methods. The change of bundle size over time and after several comparatively gentle sonication cycles of suspensions at various temperatures is reported. A novel technique is presented that produces a more homogeneous nanotube dispersion by lowering the temperature during sonication. We produce evidence that temperature influences the suspension stability, and that low temperatures are preferable to obtain better dispersion without increasing damage to the CNT walls.

Influence of the geometry of an immersed steel workpiece on mass transfer coefficient in a chemical heat treatment fluidised bed

The mass transfer during carburising in a fluidised bed and in a steel workpiece has been studied experimentally in this work. This involved carburising experiment in an electrically heated fluidised bed at 900–970°C with natural gas and air as the atmosphere. A steel workpiece was designed to provide a range of carbon transfer surfaces of different geometries in the fluidised bed, and the carbon transfer coefficient was measured at these surfaces. The carbon transfer coefficient was determined from the carbon distribution within the diffusion layer of the sample. An empirical relationship of the carbon potential as a function of carburising atmosphere, bed temperature and fluidising velocity was determined, based on the understanding of the mass transfer mechanism and analysis of the experimental results.

The group purchasing process : an investigation into the influence of the facilitator in alpine tourism

Group travel is a common feature of all tourism markets and can vary from the familiar peer group/common purpose associations of the football and cricket followers to the non-familiar co-operative travel group of the under 35 year olds bus adventures throughout Europe. This study investigates the nature of social group travel in alpine tourism. It specifically examines the phenomena of the "group facilitator"; the person within the group who takes a major role in the travel decisions and organisation on rehalf of all the other members in the travel party. The specific activities of this "group facilitator" and the role of opinion leadership, information search, organisation process, previous experience, relationship ties between the group members are examined. The 'facilitator' also influences other individuals' decision to participate who delegate selection of destination to this person as well. The 'facilitator' has many of the characteristics of an opinion leader and was recognised by group participants as a major source of information about the destination. The findings of the study have important implications for tourism marketers as they highlight an opportunity to reach many potential travellers by directly targeting one key influencer and decision maker.

Influence of the family environment on children's physical activity

This study examined the influence of the family environment on children's physical activity via four inter-related studies of over 1500 children. Findings indicated mothers' modelling of physical activity, barriers, family rules and restrictions, self-efficacy and physical features within the home environment were significant predictors of children's physical activity.

The influence of the environment on children's physical activity

Qualitative and quantitative methodologies were used to examine the influence of physical and social environments at home and in the neighbourhood, on 10-year-old children's walking and physical activity. Findings suggest that environmental factors can attenuate declines in walking and physical activity over a 16-month period.

University entrance in Queensland : post World War II challenges to the influence of the University of Queensland

From its inception the University of Queensland determined the assessment procedures that governed its student selection; while initially this determination was absolute, after 1945 challenges to the university's influence resulted in significant gains in influence by other interested groups.

‘On the influence of the scientific societies of New Zealand on the character of the nation’ - Collecting and identity at the Hawke’s Bay Philosophical Institute museum, 1874–1899

This paper explores the collection and collecting activity of the Hawke’s Bay Ph ilosophical Institute of Napier, New Zealand. It examines the development of the Institute’s museum and considers the motivations, intentions and interests of the collectors and their activity within the broader scientific and museum context. The work of two significant collectors is examined in detail: William Colenso, FLS, FRS, missionary, explorer and enthusiastic botanist, who engaged in over fifty years of correspondence and botanical exchange with Sir Joseph Hooker at Kew Gardens; and Augustus Hamilton, the curator of the museum who later became Director of New Zealand’s national collection at the Colonial Museum in Wellington. Through consideration of the Institute’s activities during the period 1874 to 1899, it is proposed that within the collection, the emergence of a distinct local identity can be discerned, during the early colonial period of Hawke’s Bay.

Influence of the blink interval on tear meniscus height in soft contact lens and nonlens wearers

Purpose: Tear meniscus height (TMH) is an indirect measurement of tear film volume. This study investigated the temporal changes in the TMH during the blink interval in the morning (8–9 am) and at the end of the day (5–6 pm) in both soft contact lens (CL) and nonlens wearers (NLW).

Methods: Fifty participants (25 CL; 25 NLW) were evaluated for their subjective symptoms, TMH, noninvasive break up time, and bulbar hyperemia at the am and pm visits on the same day. The TMH was measured at set intervals between 2 and 15 sec during the blink interval, using an optical coherence tomographer.

Results: The NLW group revealed no changes in a variety of symptoms during the day, whereas the CL group reported an increase in dryness (P=0.03) and grittiness (P=0.02) over the day. For both groups, the TMH and calculated tear meniscus volume revealed lower values immediately after the blink and increased progressively afterwards, mainly due to reflex tearing. The am tear meniscus volume values tended to be higher than the pm values for both groups, but this was not significant (NLW P=0.13; CL P=0.82). Noninvasive break up time deteriorated during the day for both groups but was only significant for the CL group (P=0.002), whereas bulbar hyperemia revealed no statistically significant change for either group.

Conclusions: Reflex tearing may play a substantial role in the TMH differences observed over the blink interval. Standardization of the time when a TMH measurement is performed will be valuable in comparing tear film clinical studies.

π-Selective stationary phases: (III) Influence of the propyl phenyl ligand density on the aromatic and methylene selectivity of aromatic compounds in reversed phase liquid chromatography

The retention characteristics of phenyl type stationary phases for reversed phase high performance liquid chromatography are still largely unknown. This paper explores the retention process of these types of stationary phases by examining the retention behaviour of linear PAHs and n-alkylbenzenes on a series of propyl phenyl stationary phases that have changes in their ligand density (1.23, 1.31, 1.97, 2.50 μmol m⁻²). The aromatic and methylene selectivities increased with increasing ligand density until a point where a plateau was observed, overall the propyl phenyl phases had a higher degree of aromatic selectivity than methylene selectivity indicating that these columns are suitable for separations involving aromatic compounds. Also, retention characteristics relating to the size of the solute molecule were observed to be influenced by the ligand density. It is likely that the changing retention characteristics are caused by the different topologies of the stationary phases at different ligand densities. At high ligand densities, the partition coefficient became constant.

π-Selective stationary phases: (I) Influence of the spacer chain length of phenyl type phases on the aromatic and methylene selectivity of aromatic compounds in reversed phase high performance liquid chromatography

Phenyl type stationary phases of increasing spacer chain length (phenyl, methyl phenyl, ethyl phenyl, propyl phenyl and butyl phenyl, with 0–4 carbon atoms in the spacer chain, respectively) were synthesised and packed in house to determine the impact that the spacer chain length has on the retention process. Two trends in the aromatic selectivity, q_aromatic, were observed, depending on whether the number of carbon atoms in the spacer chain is even or odd. Linear log k′ vs ϕ plots were obtained for each stationary phase and the S coefficient was determined from the gradient of these plots. For the phenyl type phases, the S vs n_c plots of the retention factors of linear polycyclic aromatic hydrocarbons vs the number of rings exhibit a distinct discontinuity that between 3 and 4 rings, which increases with increasing spacer chain length for even phases but decreases for odd phases. Accordingly, we suggest that the retention factors depend differently on the number of carbon atoms in the spacer chain depending on whether this number is even or odd and that this effect is caused by different orientations of the aromatic ring relative to the silica surface.

Buses, cars, bicycles and walkers the influence of the type of human transport on the flight responses of waterbirds

One way to manage disturbance to waterbirds in natural areas where humans require access is to promote the occurrence of stimuli for which birds tolerate closer approaches, and so cause fewer responses. We conducted 730 experimental approaches to 39 species of waterbird, using five stimulus types (single walker, three walkers, bicycle, car and bus) selected to mimic different human management options available for a controlled access, Ramsar-listed wetland. Across species, where differences existed (56% of 25 cases), motor vehicles always evoked shorter flight-initiation distances (FID) than humans on foot. The influence of stimulus type on FID varied across four species for which enough data were available for complete cross-stimulus analysis. All four varied FID in relation to stimuli, differing in 4 to 7 of 10 possible comparisons. Where differences occurred, the effect size was generally modest, suggesting that managing stimulus type (e.g. by requiring people to use vehicles) may have species-specific, modest benefits, at least for the waterbirds we studied. However, different stimulus types have different capacities to reduce the frequency of disturbance (i.e. by carrying more people) and vary in their capacity to travel around important habitat