This thesis reports on research that examines the early stage invasion process of Asparagus asparagoides (L.) W. Wight (bridal creeper), primarily a bird-dispersed weed, in a remnant vegetation patch. The study site is on Phillip Island, approximately 100 kilometres south east of Melbourne, Victoria. Asparagus asparagoides invasion of the remnant vegetation reserve is a relatively recent phenomenon. Landscape elements that affect bird dispersal and vegetation types that affect seedling establishment may be important factors that limit or enhance the spread of A. asparagoides. A systematic sampling strategy was adopted and data collected for a variety of landscape and vegetative variables including cover and abundance of A. asparagoides and the data were presented in a Geographic Information System (GIS). Preliminary results show that the distribution of A. asparagoides within a remnant vegetation patch is not random. It appears to have entered the reserve from two boundaries, spreading toward the centre, which to date remains sparsely colonised despite the capacity of this weed to spread rapidly over long distances by birds. A number of other outcomes are noted. Asparagus asparagoides establishment is prevented in pasture where sheep and cattle graze, and paddocks subjected to tillage practices. The exclusion of grazing in fenced off vegetation in pastures demonstrates rapid weed establishment and colonisation several hundred metres from main infestation. Field observation and visual inspection of temporal progress of invasion (using above ground weed density with tuber appearance to infer age) appear to suggest that invasion into remnant is associated with the track network. This age/density assumption is strengthened when spatial distribution is examined using a data set where low-density values for A. asparagoides are removed and compared with a data set using all A. asparagoides density values. The mapping of A. asparagoides in fenced off farm remnants suggests that velocity of spread at 191m/yr is a considerable underestimate. Subsequent analysis shows that the spatial distribution of A. asparagoides is not completely spatially random while intensity surface analysis highlights regions of low and high intensity located near track network. Mapping a density surface within GIS provided confirmatory evidence for the establishment of satellite clusters along the track network. The change in the intensity surface observed using the two data sets (lowdensity values and all density values) is also consistent with an expanding invasion occurring between two time periods. Spatial point pattern analysis using K-function statistics shows that xxii the clustering observed using GIS appears to be occurring at two scales or distances (130m- 160m and 195m-205m). The association between tracks and the invasion process observed in the initial stages of the study is examined. There is a change in density as a function of distance from a track where the density of A. asparagoides appears to reduce the further away from the track a site is and this relationship holds regardless of track width. The final stages of the study look at the development of a predictive model. Visual exploration of the data through mapping in a GIS and field observation made during data collection provide the starting point for the development of logistic models to estimate the probability of A. asparagoides presence. Finally the best overall logistic model is applied to a second independent site to determine the general applicability of the model. A number of variables that impact on the presence of A. asparagoides, particularly during the initial stages of the invasion process, are identified. While all the identified variables and the overall model are statistically significant, the model is found to correctly predict presence/absence in only 67% of cases overall. The model however could be expected to correctly predict the presence of A. asparagoides in 74% of cases and has a false positive rate of 40%. The model is applied at a second independent site and found to have an overall percent correct rate of 80% and correctly predicted A. asparagoides presence in 94% of cases. The variables identified as influential in the early stage of invasion are relatively easy to acquire by simple field survey that does not require specialist skills. When considering the model as a tool for the management of remnant vegetation communities, high false positive rates may lead to limited resources being spent on searching sites where there is no weed. However, a high false negative rate would have a larger impact on the management of the weed since the undetected infestations would form sources for new propagules. The model performs well from this point of view in that it provided low false negative rates at both sites. The value of the predictive model is its ability to provide managers with information regarding specific areas to target for weed eradication and management can use the model to assess the effectiveness of any control measures by going back to obtain new cover density data, then using the model to examine the changes over time. The model also provides a starting point for the development of a generic model of A. asparagoides invasion at sites outside of Phillip Island and could also provide the starting point for developing models that could be used for other bird-dispersed fleshy-fruited weed species.

Polymer dispersed liquid crystal (PDLC) films, consisting of micro-sized domains of a liquid crystal dispersing in a polymer matrix, serve as the basis of a variety of high-efficiency electro-optical effects. The thermo-optical properties of the PDLCs were investigated in this thesis. The thermal properties and the morphologies of four low molar mass mesogens were studied by DSC and polarized optical microscope (POM). There were significant super cooling/heating effects on the first order phase transitions but not on the mesophase transitions. The structural effects on the transition temperature were investigated. Between the two 4-alkoxybenzoic acids mesogens, the clearing temperature of 4-(octyloxy)benzoic acid was higher than 4-(decyloxy)benzoic acid because of the increasing chain length. Trans-4-methoxycinnamic acid had the highest melting temperature among the four mesogens despite the molar mass because the carboxylic acid termini of trans-4-methoxycinnamic acid gave rise to strong intermolecular attractions. The smectic phases of 4-(octyloxy)benzoic acid were classified as head-to-head bilayer orientational smectic structures, SmA2 and SmC2, respectively, by wide angle X-ray diffraction through measuring the d spacing of the liquid crystal. The total solubility parameter was used to evaluate matching a polymer-LC-solvent combination. PDLC films were prepared by the solvent induced phase separation method and suitable morphologies were achieved by thermal induced phase separation. The phase transition temperatures of PDLCs were shifted to a lower temperature due to the polymer dispersion effects. Different mesophases were observed in PDLC films when LC exhibited different mesophases. The LC fractions in the droplets were calculated from the nematic to isotropic enthalpies through the Smith equation. Two factors, thermal cooling rate and the LC concentration, which affect the size of the droplet dispersed in the polymer matrix, were investigated in the PVC dispersed 4,4'-azoxyanisole. The phase transitions of pHEMA dispersed 4-(octyloxy)benzoic acid and PVC dispersed 4,4'-azoxyanisole were investigated by TMDSC and quasi-isothermal TMDSC. The TMDSC results were analysed by the two approaches, reversing and non-reversing heat flow and complex heat capacity. The results of the phase transitions of the two PDLCs illustrated that in the PDLCs it involved both non-reversing, melting, and reversing, clearing and the transition between two mesophases. In the non-reversing transition, the transition temperature would be affected by super cooling/heating and the results obtained in the experiments were dependent on the experimental conditions, such as the heating or cooling rate, sample size and purge gas flow rate. However, in the reversing transition process, there were no super cooling/heating effects observed and it seemed that the experimental conditions were not so critical. Results could be monitored by Lissajous figures obtained from the quasi-isothermal TMDSC. The plots of modulated heat flow versus the derivative of modulated temperature can be used to alert to unfavorable experimental conditions where loss of system linearity could be seen.

This thesis presents experimental studies of gas phasemolecular relaxation after excitation with synchrotron photonsin the 15-35 eV and in the 70-350 eV regions. In the 15-35 eV region, molecular relaxation by neutraldissociation processes and non Franck-Condon effects in N2 and O2 molecules have beenstudied by means of dispersed fluorescence and photoelectronspectroscopy experimental techniques, respectively. From thedispersed fluorescence data, excitation functions for themeasured atomic fluorescence spectra have been obtained. Fromthe recorded photoelectron spectra vibrational branching ratioshave been produced. The results obtained reveal that Rydbergseries and singly and doubly excited valence states of theappropriate symmetry energetically accessible in the studiedregion and interactions between themaccount for most of theobserved effects in these two type of experiments. In the 70-350 eV range, molecular relaxation processesresulting in fragmentation of CD4 and SF6 after absorption ofsynchrotron light have been studied by energy resolved electronion coincidence technique using a multicoincidence experimentalstation developed by our group during the last five years forsuch type of experiments. The coincidence measurements yieldedmass spectra from which information about the kinematics of thedetected fragments has been deduced by means of Monte Carlosimulations of the experimental peak shapes. The obtainedresults show completely different dissociation patternsdepending on the molecular electronic states studied. Thesepatterns reflect the bonding properties of the excited orbitalsand they permit the description and in some cases theidentification of the different molecular relaxation pathwaysobserved. The achievements presented in this thesis exemplifythe potential of the multicoincidence station used in thereported experiments.

As a contribution to the emerging field of practice-based research in the arts, this thesis aims to activate space, experience and the concept in-between. As the in-between cannot be defined ahead of the rhythmic process it carries out and of which it is a part – a rhythm inherent in the city itself and in knowledge production – it is necessary to produce rhythmic relations between bodies, sites and concepts. An art experiment, a forty-two meter high swing mounted on the bridge, Älvborgsbron, in Gothenburg harbour, Sweden, serves as the point of entry to the thesis. A dancer in the swing moved slowly between the bridge and the ground, captured in a rhythmic experience of being earthbound and then weightless. The swing project, together with other rhythmic processes such as walking, weaving and acting physics, activate spatial, temporal and theoretical dimensions of the in-between. Merging my roles as an artist, teacher and researcher by pragmatic production, perception and concepts it becomes possible to transform the rhythms between the examples:   1. A swing mounted on a bridge; one of my art projects. 2. Walking and mapping strategies; as developed in my courses taught at the School of Architecture. 3. The myth about Penelope weaving. 4. Rhythmic relations between bodies and machines at CERN, the particle physics laboratory outside Geneva, a place that is important for several of my art projects.   Creative production aims to expand the capacity of the body.  By employing a bridging structure, spaces in-between are activated thus revealing the power and danger in-between. In that production collective processes merge, creating “social and collective machines” and another reality between:   1. bridge/swing/dancer, 2. map/walking/site, 3. war/loom/weaving, 4. theory/detector/bodies.   These rhythmic processes oscillate between representation and the complex forces of daily activities. However, it is not the rhythm itself that activates spaces in-between but, rather, the changing of directions of the rhythm: from moving to be in motion; from walking forward to walking and falling; from weaving cloth to producing time; from doing physics to acting physics. Activating in-between spaces means activating differences and another way of producing knowledge, a well-known strategy in contemporary art: a production of potential realities, in a constant interaction between concepts and spatial transformations. / QC 20100909

Geographically dispersed organizations are becoming increasingly common, however, the organizational culture is often weaker in this type of organization due to geographical distances. One important aspect of the organizational culture is the organizational values, and if shared by all organizational members they can benefit the company on many levels, for example by increasing motivation and communication. If employees, on the other hand, fail to interpret the organizational values it may lead to decreased working moral and overall dissatisfaction. In family businesses it is the values of the family that constitute the organizational values, and these may be difficult to communicate to non-family employees, because family businesses often rely on informal communication.   The purpose of this thesis is to describe how non-family employees interpret the organizational values of a family business, as well as to increase the understanding of whether geographical distance affects their interpretation. In this thesis we have conducted a qualitative case study, in which ten semi-structured interviews were made in a geographically dispersed family business. We have assumed an employee perspective and have, thus, interviewed non-family employees on the different geographical locations of this family business.   The findings from the empirical data showed that the case studied organization does not have any formally written organizational values and the non-family employees have as a result interpreted the values slightly differently. The employees state the organizational values in general terms, which would make them applicable to any organization, or even society at large.   In the analysis we compare the theoretical framework and the empirical findings in order to present conclusions for the organization being studied. The analysis will be divided into themes; organizational structure, organizational culture and values as well as the relation between the non-family employees and the family business.   We were able to conclude that informal communication is not sufficient in order to efficiently communicate the organizational values in a geographically dispersed organization. Nevertheless, the geographical distance for each workplace respectively could not be identified as the only influencing factor that affects the employees’ interpretation of the organizational values. The organizational structure emerged as a contributing factor. The non-family employees’ interpretations were broad and general in terms of the organizational values. One of our recommendations is for the organization to write down the organizational values and distribute them throughout the organization, which will enable the organizational values to be correctly interpreted by all organizational members.

Dispersed spectrum cognitive radio systems represent a promising approach to exploit the utilization of spectral resources to full extent. Therefore, the performance analysis of such systems is conducted in this research. The Average symbol error probability of dispersed spectrum cognitive radio systems is derived for two cases: where each channel realization experiences independent and dependent Nakagami-m fading, respectively. In addition, the derivation is extended to include the effects of modulation type and order by considering M-PSK and M-QAM modulation schemes. We then study the impacts of topology on the effective transport capacity performance of ad hoc dispersed spectrum cognitive radio systems where the nodes assume 3- dimensional (3D) configurations. We derive the effective transport capacity considering a cubic grid distribution. In addition, numerical results are presented to demonstrate the effects of topology on the effective transport capacity of ad hoc dispersed cognitive radio systems.

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<p>This thesis presents experimental studies of gas phasemolecular relaxation after excitation with synchrotron photonsin the 15-35 eV and in the 70-350 eV regions.</p><p>In the 15-35 eV region, molecular relaxation by neutraldissociation processes and non</p><p>Franck-Condon effects in N2 and O2 molecules have beenstudied by means of dispersed fluorescence and photoelectronspectroscopy experimental techniques, respectively. From thedispersed fluorescence data, excitation functions for themeasured atomic fluorescence spectra have been obtained. Fromthe recorded photoelectron spectra vibrational branching ratioshave been produced. The results obtained reveal that Rydbergseries and singly and doubly excited valence states of theappropriate symmetry energetically accessible in the studiedregion and interactions between themaccount for most of theobserved effects in these two type of experiments.</p><p>In the 70-350 eV range, molecular relaxation processesresulting in fragmentation of CD4 and SF6 after absorption ofsynchrotron light have been studied by energy resolved electronion coincidence technique using a multicoincidence experimentalstation developed by our group during the last five years forsuch type of experiments. The coincidence measurements yieldedmass spectra from which information about the kinematics of thedetected fragments has been deduced by means of Monte Carlosimulations of the experimental peak shapes. The obtainedresults show completely different dissociation patternsdepending on the molecular electronic states studied. Thesepatterns reflect the bonding properties of the excited orbitalsand they permit the description and in some cases theidentification of the different molecular relaxation pathwaysobserved. The achievements presented in this thesis exemplifythe potential of the multicoincidence station used in thereported experiments.</p>

Heavy oil derived from oil sands is becoming an important resource of energy and transportation fuels due to the depletion of conventional oil resources. However, bitumen and heavy oils have a low hydrogen/carbon ratio and contain a large percentage of sulfur and nitrogen heterocyclic compounds. At the level of deep desulfurization, aromatic poly-nuclear molecules, especially nitrogen-containing heterocyclic compounds, exhibit strong inhibitive effect on hydrodesulfurization (HDS) due to competitive adsorption on catalytically active sites with sulfur-containing molecules. Therefore, it is necessary to study the HDS of refractory sulfur-containing compounds and also the effect of nitrogen-containing species on the deep HDS for achieving the ultra low sulfur specifications for transportation fuels. Additionally, the cost of H2 increased in recent years and a bitumen emulsion upgrading technique using an alternative in-situ H2 generated via the water gas shift (WGS) reaction during the hydro-treating was developed in our group. In the present study, a kind of nano-dispersed unsupported MoSx based catalyst was developed and used for hydrodesulfurization, hydrodenitrogenation (HDN) and upgrading bitumen emulsions. Objectives of this thesis were to (1) improve the catalytic activity of the nano-dispersed Mo based catalysts towards the HDS and HDN reactions of refractory sulfur-/nitrogen-containing compounds; and (2) compare the reactivity of in-situ hydrogen generated via the WGS reaction versus externally provided molecular hydrogen in HDS and HDN reactions to improve the efficiency of the bitumen emulsion upgrading technology developed by our group. In the present study, to stimulate the reaction system of bitumen emulsion, water was added into the organic reaction system, so there are different phases in this reaction system. To investigate the activity of the catalyst, the catalyst particles dispersed in different phases were characterized separatedly via HRTEM-EDX. After HRTEM-EDX study, all phases were mixed up and dried for further characterizations, BET, SEM, and XRD. The catalyst prepared in in-situ hydrogen was found to have higher surface area and smaller particle size than the one made in molecular hydrogen. The presence of sulfur-/nitrogen-containing compounds in the preparation system caused significant changes in the morphology of dispersed Mo sulfide catalyst according to HRTEM observations. Refractory sulfur-containing compounds of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) were used as model compounds in HDS studies. The simultaneous HDS of both model compounds was performed at different reaction temperatures from 330??C to 400??C. The effect of the reaction temperature on the WGS reaction in the presence of sulfur-containing model compounds was reported. A kinetic model for HDS reactions was proposed and used in discussing experiment results. The relative HDS reactivity of 4,6-DMDBT to DBT using dispersed Mo sulfide catalyst in in-situ hydrogen was found to be higher than the reported results which were obtained over supported catalysts. Nickel and potassium were introduced into Mo sulfide catalysts as promoters and their effect on the WGS reaction and the HDS reaction were discussed. The simultaneous HDS was carried out in the two different hydrogen sources. The in-situ hydrogen reaction system showed higher conversion and desulfurization results of both sulfur model compounds. This observation has been found to be mainly contributed by the higher activity of the Mo sulfide catalyst prepared in in-situ H2. Strong inhibitive effect of nitrogen-containing compounds, basic quinoline or non-basic carbazole, on the HDS of refractory sulfur model compounds was observed and discussed. Basic quinoline was a much stronger inhibitor than non-basic carbazole. The two HDS reaction pathways were affected by nitrogen-containing compounds to different extents. The HDN of quinoline over the dispersed Mo sulfide catalyst using in-situ hydrogen had been studied extensively by a previous member in our group. In this thesis, the HDN of carbazole was studied. From the identification of HDN products of carbazole, a HDN reaction network was proposed. The HDN of carbazole was processed at different reaction temperatures. The WGS reaction was not inhibited in the presence of carbazole. Comparable reactivity of the two hydrogen sources towards the HDN of carbazole was observed. The presence of 4,6-DMDBT caused significant effect on the HDN of carbazole due to the competitive adsorption on the catalyst surface.

The background in which global organisations operate in at present is very competitive. In an ever faster growing global economy the role of the entrepreneur within the large organisation becomes more and more important to ensure the company keeps the competitive edge. The Linde Group is a world class company with a world class management strategy and systems to support the strategy. Part of the The Linde Group management strategy is being a high performing organisation, wanting to give all employees the opportunity to contribute to improvement by sharing their ideas with the company. This study was done at African Oxygen Limited, South Africa, a regional business unit in Africa for The Linde Group. African Oxygen Limited embarked on various programmes to create opportunities for employees to think in an entrepreneurial way. Middle managers at African Oxygen Limited play an important role in the innovation programs implemented at African Oxygen Limited. Against this background, this study seeks to confirm whether African Oxygen Limited, South Africa has a true entrepreneurial climate and whether the middle management level involved with these initiatives share this perception. Corporate entrepreneurship is characterised by people who are innovative, creative, spend time and take risks. To support these entrepreneurial activities, the organisation needs a climate and culture that is beneficial to these activities. An entrepreneurial orientation within an organisation is marked by dimensions such as innovativeness, pro–activeness, risk–taking, competitive aggressiveness and autonomy. The entrepreneurial behaviour among middle level managers is most critical to the effective implementation of corporate entrepreneurship. The primary objective of this study was to assess the entrepreneurial climate in African Oxygen Limited and to make recommendations to foster corporate entrepreneurship within the organisation. The literature review was instrumental to gather secondary data on corporate entrepreneurship and to understand its dynamics. In order to gain primary data, quantitative research was carried out. The study population comprised lower and middle management, who were requested to complete questionnaires. This was followed by statistical analysis. The empirical results indicate no practical significance in respondents' perception based on the gender of the respondents. However, the results do indicate practical significant differences between the relationship between the groups of middle and lower management level with respect to entrepreneurial climate and the perceived organisational success. An evaluation of the corporate entrepreneurial climate in the organisation was performed and the average mean for the study calculated. Seven out of 13 constructs evaluated had a mean above the average mean of x = 3.502, the other six constructs evaluated had a mean ranked lower than the average mean. All of the constructs still had a mean above three out of five. All four of the used variables measuring the perceived organisational success, were reported by respondents to have a mean above three which is the neutral point. The average mean of the perceived success of the organisation was 3.688. It was clear that the constructs for perceived organisational success had a fairly strong presence, but there is still room for improvement. With reference to the entrepreneurial climate within Afrox the conclusion is that it is not optimally entrepreneurial and initiatives put into practice that should encourage entrepreneurial behaviour, are falling short. The study concludes with practical recommendations on assessment of the achievement of objectives and suggestions for future research. / Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2011.