The application of synchrotron radiation and in particular X-ray absorption spectroscopy to matrix isolated species

This review provides comprehensive coverage of the application of X-ray absorption spectroscopy (XAS, XAFS, EXAFS, and XANES) to matrix isolated species. As X-ray absorption spectroscopy provides structural data without the need for long range order it has been applied to a large number of systems to yield unique structural data about both the matrix isolated species, and their interactions with the matrix host. To put the work into perspective there is a tutorial introduction to the theoretical background of X-ray absorption spectroscopy, data content, processing and analysis. In addition there is brief coverage of the use of other synchrotron radiation techniques for the study of matrix isolated species, and a consideration of future perspectives

Long Distance Walking Tracks: impacts and experiences: biophysical impacts and psychosocial experiences associated with use of long distance walking tracks in the Wet Tropics region of North Queensland

This multidisciplinary doctoral research project investigated visitor impacts and visitor experiences associated with two long-distance walking tracks within the Wet Tropics region of North Queensland, Australia. A literature review demonstrated there has been minimal research conducted to date in relation to the biophysical impacts and psychosocial experiences of long-distance walkers in all locations, but particularly within the Wet Tropics region. Since encounters between visitors and a recreational site have the potential to generate either positive or negative biophysical and social impacts at the setting, in addition to positive or negative psychological impacts for the individual user (Bentrupperbaumer and Reser, 2000), this project represented a timely attempt to examine both research avenues from theoretical and applied perspectives. Both long-distance walking tracks investigated in this research were located within World Heritage listed protected areas. World Heritage listing is an acknowledgement that locations possess international significance and places particular responsibilities upon management agencies to conserve, present, rehabilitate, and transmit their attributes to future generations (Wet Tropics Management Authority, 2000). The Mt Bartle Frere Track is situated within Wooroonooran National Park in the Wet Tropics of Queensland World Heritage Area, while the Thorsborne Trail is located on Hinchinbrook Island National Park within the Great Barrier Reef World Heritage Area. This research utilised a range of methodologies derived from both the natural and social sciences, and a human-environment transactional model specifically developed for outdoor recreation settings (Bentrupperbaumer and Reser, 2000, 2002) was adopted as the overarching theoretical and analytical framework for the study. Biophysical impacts were assessed using rapid assessment methodology following the selection of a range of suitable environmental indicators. Impacts were recorded within one metre square quadrants and along 20 metre linear transects at 100 sampling points on each track. Spatial comparisons were made among sampling zones (tread, buffer, and control), and vegetation types on each track. Temporal comparisons were made between wet and dry season results. Psychosocial experiences were assessed using a self-report questionnaire administered to hikers via a range of distribution methods over a one year period using a convenience sampling strategy. Spatial comparisons indicated that biophysical impacts were predominantly confined to the tread and buffer zones, and were more prevalent in proximity to locations where hikers congregated such as camping grounds, lookouts, and swimming holes. The biophysical impacts that were of most concern on the Mt Bartle Frere Track included track widening, exposed mineral soil, erosion, and the inadequate disposal of human body waste. Trampling impacts of most concern on the Thorsborne Trail included exposed mineral soil, human littering, human vegetation damage, and social trails. Temporal comparisons of biophysical impacts between wet and dry season sampling suggested that some track widening occurred during the wet season on both tracks, presumably as a consequence of hikers attempting to avoid muddy or waterlogged track sections. Exposed mineral soil was most prevalent during the dry season on both tracks when visitation levels were highest. Mean organic litter depth was deepest during the wet season on both tracks, with 'significant seasonal reductions in litter being recorded on the Mt Bartle Frere Track. Incidences of human vegetation damage were also more widespread during the wet season on both tracks. Seasonal comparisons of biophysical impacts were discussed from a recreation ecology perspective using the concepts of resistance and resilience. Psychosocial experience surveys (N = 623) provided a number of insights in relation to the profile of long-distance walkers using these two tracks. Respondents were typically young, well educated, highly experienced in the use of long-distance tracks, and primarily had experiential-based motivations for undertaking their walk. A substantial proportion of respondents were either repeat visitors or had learnt about the existence of their respective tracks via word of mouth, while only a minority of hikers had used formal information sources such as visitor information centres and the internet. While a majority of respondents positively appraised the natural, built, and social environments they encountered, many also identified a number of specific factors that had detracted from their experiences. Respondents from the Mt Bartle Frere Track were most concerned about the prevalence of soil erosion, feral animals, and the lack of track marking to assist wayfinding. Thorsborne Trail respondents were most concerned about the number of other people they encountered in camp grounds, encounters with large groups, human litter, and feral animals. Although a majority of respondents from both locations approved of current track management, many indicated their support for a range of possible management interventions. Most respondents from each track were generally satisfied with their overall experience and the vast majority would be willing to undertake their respective hikes again, although satisfaction levels were higher among Thorsborne Trail respondents. This research has enhanced theoretical understandings of human-environment transactions within a long-distance walking track context. These were explored in some detail using a conceptual mapping progression that compared the relative contributions that different domains within the human-environment transactional model make to experiences within different outdoor recreation settings. The research also made a number of scientific contributions to the human-environment transactional model through reaffirming and extending the model's core aspects of multidisciplinarity, simultaneous assessment, multidimensionality, reciprocity and interconnectedness. Use of the human environment transactional model has also provided a number of applied insights that may assist managers to better understand the linkages that exist between impact upon environment and impact uppon people and the interconnectedness of human behaviour/ experience/ biophysical impact. The research has enabled the formulation of a number of general principles that will hopefully assist management of other long-distance walking tracks within the Wet Tropics region and also generated a number of specific site and visitor management recommendations for each track, some of which have already been implemented. The results obtained from these tracks can be cautiously extrapolated to other long-distance walking tracks within tropical rainforest environments provided that site-specific factors are taken into consideration

Exploring Channel Evolution with History

This paper discusses the evolution of the distribution channel of the Australian Information Communication Technology (ICT) industry over a 21 year period, introducing an effectiveness of the methods used to investigate this. The paper opens with a discussion of the value of historical analysis, arguing that ‘applying history helps us by identifying the reasons for important transitions’. A historical focus both allows us to interpret the past via the identification of key events that triggered change; and by considering the patterns that these form; we are able to surmise the impact of present and future events. The practical problems associated with extended longitudinal research have been well documented and include substantial resources required, drop out, poor choice of focus (as one cannot foresee if research subjects will evolve in ways of interest to the researchers), etc. This paper illustrates an effective way of overcoming at least some of these problems by using archival material in combination with narrative event analysis and any necessary clarification and augmentation provided via depth interviews with industry experts. Narrative event analysis enables consideration of the important explanations that can emerge from considering timing, order and interaction of events over simple correlation between variables. The analysis enables consideration of ‘moving pictures’ of networks as they evolve rather than only static pictures. The analysis of archival data avoids problems of imperfect recall and because the material used (articles in trade journals published during the review period) is from the perspective of many different observers, we also avoid dependence on the perspectives and interpretations of only a few observers. The paper focuses on a description of the classification and coding of the archival data for events using structural conditions topography. One of the key findings is that the following mechanisms/conditions are appropriate for classification and interrelating of the processes and the events of the channel’s evolution. Market conditions which relate to preferred structure of the optimum channel network, size of market, industry growth, competition relating to number of vendors and distribution partners in the channel, long term strategic trends and the frequency of mergers and acquisitions were important drivers. Product conditions are connected to market conditions and these play a particularly important role in the information technology market where there is a constant emergence of new products and technology with products superseding other products and with short product life-cycles. Influence conditions (i.e. social mechanisms) are concerned responses to product and market conditions, in particular with how vendor distributor relationships are managed by vendor distributor management. This involves fit in terms of organisation culture and expectations between vendor and distributor, fit of personality of account manager on vendor distributor side, inter personal skills of account manager, communication frequency, interpersonal skills and how conflicts are managed. Commercial agreement conditions (risk/return profile of distribution) are the final key mechanism. This relates to the vendor commercial distributor agreement, basic functions, channel strategy, nature of commercial relationship, performance targets and formal reporting. The paper presents a portion of the analysis of the archival data using this frame to show the interrelationships of these four categories. Structural conditions have a significant impact on the structural evolution of the channel and on the relationships within the channel of distribution. Structural evolution is driven in part by market conditions. Mergers and acquisitions have resulted in increased channel consolidation and the emergence of fewer channel partners and this has moved the relationship processes from high conflict and adversarial to highly collaborative forms – though these do often include considerable conflict. Product conditions relating to convergence of new product technology over time have also impacted on channel structure expanding the channel further into retail and online alternatives. However this greater complexity of tasks (in conjunction with adversarial history) has resulted in the need for increasing levels of channel coordination to manage and resolve the considerable conflicts that continue to emerge. Evolution of commercial conditions has resulted in more professionalism and a formalised partner planning process which in turn is impacting on the influence conditions. The paper concludes with a discussion of further development of this methodology and the further analysis that will be undertaken.The symposium is organised on behalf of AAHANZBS by the Business and Labour History Group, The University of Sydney, with the financial support of the University’s Faculty of Economics and Business

Structure and electronic properties of the quasi-one-dimensional Ba₂Co₁₋ₓZnₓS₃ series

This work focuses on the structure and physical properties of the solid solution Ba₂Co₁₋ₓZnₓS₃ (0 ≤ x ≤ 1), a family of quasi-one-dimensional sulfides with end members Ba₂CoS₃ and Ba₂ZnS₃. The structure of selected compounds with increasing Zn²⁺ content has been analysed using, neutron diffraction, TEM and EXAFS and the physical properties via magnetic susceptibility and resistivity measurements. The progressive substitution of the non-magnetic Zn²⁺ cation for Co²⁺ rapidly destroys the antiferromagnetic transition present at 46 K in the quasi one-dimensional Ba₂CoS₃, leading to paramagnetic behaviour down to the lowest investigated temperature (5K) for compounds with x > 0.25. For compounds with x ≥ 0.4, a pure CW regime is recovered around 300 K, yielding effective moments consistent with the g factor of the tetrahedrally coordinated Co²⁺ previously determined for Ba₂CoS₃. The Zn²⁺/Co²⁺ substitution also removes the metallic-like behaviour of Ba₂CoS₃ causing an increase in the value of the resistivity with all the Ba₂Co₁₋ₓZnₓS₃ compounds showing semiconducting behaviour. The negative magnetoresistance of Ba₂CoS₃ is improved by the Zn²⁺/Co²⁺ substitution, with values of – 6% for Ba₂Co₀.₇₅Zn₀.₂₅S₃, – 9% for Ba₂Co₀.₅Zn₀.₅S₃ and – 8% for Ba₂Co₀.₂₅Zn₀.₇₅S₃. However, there does not seem to be a correlation between the values of the resistivity and the magnetoresistance and the content of Zn²⁺, leading to the hypothesis that transport properties may be linked more closely to extrinsic properties

The Wars We Remember: An Essay in Comparative Memory Work

The Ohio State University Mershon Center for International Security StudiesNigel Young is visiting distinguished scholar of peace studies at Earlham College. He has been active in transnational peace activity for more than 50 years, and has held several academic positions in sociology, politics, and peace studies at over a dozen universities and colleges worldwide, including as professor and director of peace studies at Colgate University (1984-2004), and as senior research fellow at the International Peace Research Institute in Oslo (1981-84).Mershon Center for International Security StudiesEvent Web Page, Streaming Video, Event Photo

A matrix isolation and computational study of molecular palladium fluorides : does PdF₆ exist?

Palladium atoms generated by thermal evaporation and laser ablation were reacted with and trapped in F₂ /Ar, F₂ /Ne, and neat F₂ matrices. The products were characterized by electronic absorption and infrared spectroscopy, together with relativistic density functional theory calculations as well as coupled cluster calculations. Vibrational modes at 540 and 617 cm⁻¹ in argon matrices were assigned to molecular PdF and PdF₂ , and a band at 692 cm⁻¹ was assigned to molecular PdF₄ . A band at 624 cm⁻¹ can be assigned to either PdF₃ or PdF₆, with the former preferred from experimental considerations. Although calculations might support the latter assignment, our conclusion is that in these detailed experiments there is no convincing evidence for PdF₆

Experimental evidence for the molecular molybdenum fluorides MoF to MoF6: a matrix isolation and DFT investigation

All of the molecular molybdenum fluorides, MoF to MoF6, have been synthesised from the reaction of thermally evaporated molybdenum atoms with fluorine molecules and atoms, trapped in argon matrices, and characterised by matrix isolation IR spectroscopy in conjunction with DFT calculations. This includes the first spectroscopic characterisation of MoF and MoF2, the latter of which is very bent with a bond angle of ca. 133°, the reassignment of the IR spectral data for trigonal planar MoF3, the observation of tetrahedral MoF4, the assignment of new features to MoF5 which displays a Jahn-Teller distorted trigonal bipyramidal structure, and octahedral MoF6. When the reaction of fluorine molecules and heated molybdenum is allowed to take place, MoF6, MoF4 and (MoF5)3 are observed

A photodiode for detection within molecular diagnostics

A photodiode (200), for instance a PN or a PIN photodiode, is disclosed. The photodiode receives incident radiation having first and second spectral distributions, where the first spectral distribution is spectrally shifted from the second spectral distribution. The photodiode has a first semiconductor layer (211) capable of absorbing incident radiation (231) having a first spectral distribution without generating a photocurrent, while simultaneously transmitting incident radiation having a second spectral distribution to the intrinsic layer (212) for generating a photocurrent (213). The photodiode may be used in connection with detecting the presence of target molecules that has been labeled with labeling agents, such as fluorophores or quantum dots. The labeling agents are characterized by the Stokes shift and, therefore, they emit fluorescent radiation having the second spectral distribution that is spectrally shifted from the illumination radiation having the first spectral distribution