• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2737
  • 1318
  • 529
  • 466
  • 262
  • 245
  • 123
  • 80
  • 38
  • 35
  • 32
  • 30
  • 27
  • 27
  • 20
  • Tagged with
  • 7385
  • 2107
  • 1239
  • 1064
  • 1018
  • 735
  • 678
  • 650
  • 609
  • 587
  • 477
  • 387
  • 373
  • 325
  • 313
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
541

The impact of environmental conditions on young entrepreneurs' start-up activities / Dopad environmentálních podmínek na vznik start-upů mladých lidí

Blšáková, Daniela January 2017 (has links)
The diploma thesis deals with the influences that affect young people aged 18 to 24 in the establishment of start-ups. The main aim was to find out which environmental factors influence emergence of youth start-ups and how they differ in Europe, China and the US over time. The thesis describes three models that explain the entrepreneurial intentions and that serve better understanding of human behavior in setting up businesses. Further the thesis includes a description of the individual and environmental factors that are based on current studies. Due to the title of thesis only the impact of environmental factors was tested. The analysis was conducted on a public data of the Global Entrepreneurship Monitor.
542

A social work study on the impact of legislation on the practice of Employee Assistance Programmes in the South African mining industry

Mbana, Phiwe Thando Vuyo 06 May 2009 (has links)
This research project was concerned with the description of the Employee Assistance Programme (EAP) mainly in the South African mining industry. The focus was on the impact of legislation on the practice of EAP in the South African mining industry. The researcher used a qualitative approach in this applied research study. The researcher employed a phenomenological strategy within the exploratory study. This was done through the utilization of semi-structured interviews. The researcher first looked at the evolvement of EAP as a field of practice, following by a discussion of the current state of the EAP in the South African mining industry. The researcher continued by discussing relevant pieces of legislation that have a direct influence on the practice of EAP in the mining industry. The second part of the project was the empirical study. Ten respondents were drawn through the process of purposive sampling. The researcher mainly dealt with the views of four Human Resource practitioners and six EAP practitioners in the mining industry. Through this exercise, the researcher looked at what the practitioners’ views were on the role of legislation as specifically to two issues. The first was the general provision of EAP services. The second was the stipulation of the legislation according to them, pertaining the practicalities of the provision of the service. The researcher’s conclusions regarding impact of legislation on the practice of EAP in the South African mining industry can be presented in the following manner: • Legal provisions have played a significant role towards the development of the field of EAP in general; • Other implications have been difficult to implement for mostly two main reasons. The first is that they are too general and therefore are seen to mean different things to different people. The second is that the people who matter most do not know them. These are either human resources practitioners, occupational social workers and/or EAP professionals or union and/or employee representatives. / Dissertation (MSW)--University of Pretoria, 2009. / Social Work and Criminology / unrestricted
543

Elephants in the Waterberg : impacts on woody vegetation by breeding groups compared with bachelors

Frost, Jennifer Sarah 21 November 2005 (has links)
In May 1994 IFAW funded the relocation of 50 elephants from the Kruger National Park to Welgevonden Private Game Reserve in the Northern Province, South Africa. Impact by the elephants on the vegetation of this reserve has since become a concern. The aim of this study was to quantify impact by the elephants on the woody vegetation by investigating vegetation and habitat use by elephant bachelor and breeding groups. This was determined by comparing resource use between sexes within seasons, and within sexes between seasons. Data were collected at two ecological scales: feeding patch scale and habitat scale. Feeding data were collected from 202 food plots, defined from 161 elephant sightings. In the dry season, when resources are often limited, no difference in feeding patch use was found between bachelor groups and breeding groups. This may suggest a lack of inter-sexual competition and could therefore suggest that the elephant population is currently below carrying capacity. Three habitat types are available to the elephants: plateau, hillslope and valley bottom. Both bachelor groups and breeding groups preferred valley bottom in comparison with habitat availability, in both seasons. When sexes were compared within seasons, in the dry season, bachelor groups used valley bottom more and breeding groups used hillslope more. / Dissertation (MSc (Zoology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted
544

The socio-economic impact of the Pax Romana and Augustus' policy reforms on the Roman provinces

Coombes, Michael James 24 November 2008 (has links)
No abstract available / Dissertation (MA)--University of Pretoria, 2008. / Ancient Languages / unrestricted
545

The environmental impact of seepage from gold mine tailings dams near Johannesburg, South Africa

Rosner, Thorsten 20 December 2007 (has links)
Gold mining in South Africa resulted in vast volumes of waste material, mainly in the form of tailings material. Poor management of most of the tailings dams resulted in the release of acid mine drainage that in some cases caused soil degradation and water contamination underneath and around these sites. Although many tailings dams have been partially or completely reclaimed, their contaminated footprints pose a serious threat to the water quality of the underlying aquifers (e.g. dolomitic aquifers). This study investigated the geotechnical, mineralogical and geochemical parameters of eleven selected partially or completely reclaimed sites situated near Johannesburg. The main objective of the field and laboratory experiments was to assess the pathway of contaminant migration resulting from acid mine drainage from tailings materials through the unsaturated zone into the groundwater system. Comparing extractable contaminant concentrations with a soil standard from literature represents the environmental short-term impact. In contrast, total element concentrations in the soil compared with background values were used to describe the long-term impact or worst-case scenario. Extraction tests have shown that only a minor portion of contaminants (i.e. Co, Ni and Zn) is mobile in acidic soils. This implies that plant growth could be limited because of phytotoxic elements occurring in the topsoils, complicating rehabilitation measures. In addition, the soils often contain anomalous trace element concentrations, providing a pool for future contamination. Buffer minerals will eventually be depleted and the subsequent acidification of the subsoil, could result in the remobilization of contaminants from the subsoil into the groundwater system in the long term. It is important to understand the parameters, which control the balance between retention and mobility of contaminants in soils. Therefore a risk assessment approach would be required for all tailings dams and reclaimed sites to identify those sites, which need rehabilitation and to define the type and extent of remedial measures. Minimum rehabilitation requirements at reclaimed sites could consist of soil management measures such as liming and the addition of organic material and fertilisers to minimise the contaminant migration from the topsoil into the subsoil and groundwater as well as to provide suitable conditions for vegetation growth and future land use. Removal of remaining tailings and excavation of those portions of the soil, which are excessively contaminated, are necessary. Tailings dams which pose a high risk to the environment would require a well-engineered soil and vegetation cover to limit rainfall infiltration into the impoundment, and thus to reduce the oxidation of sulphide-bearing minerals such as pyrite. Long-term monitoring is an absolute prerequisite to ensure the success of rehabilitation, and therefore the safe use of land and water. / Thesis (PhD)--University of Pretoria, 2007. / Geology / Unrestricted
546

Economic analysis of the Florida Everglades restoration

Czajkowski, Jeffrey Robert 21 November 2003 (has links)
An economic valuation methodology was developed in order to monetarily quantify the benefits resulting from the Indian River Lagoon - South (IRLS) $995 million Everglades restoration project. Service flows of the IRLS were identified and their associated economic baseline values were estimated utilizing existing research. A water quality baseline for the IRLS was also established and compared with the best available standards. Benefits accruing beyond the baseline values given the completion of the IRLS restoration were estimated via benefit transfer to be approximately $159 million annually, importantly factoring in the established IRLS water quality baseline. Given these benefit results of a lower bound estimate, the project was determined not to be economically feasible, i.e., NPV < $0, via a cost-benefit analysis. However, Monte Carlo analyses provided further insights into the probability of an economically feasible restoration (36%) given the uncertainty surrounding the benefit estimation, as well as specific variables to focus on to improve this probability. This research highlights the potential significant economic value of the IRLS and the importance of properly estimating this value given the magnitude of costs.
547

Evaluation of the impact of the Northern Medical Program : perceptions of community leaders

Toomey, Patricia C. 11 1900 (has links)
Background. Access to health care in northern and rural communities has been an ongoing challenge. Training undergraduate medical students in regional sites is one strategy to enhance physician recruitment and retention in rural regions. With this goal in mind, in 2004, the Northern Medical Program was created to bring undergraduate medical education to Prince George. The NMP is also hypothesized to have wider impacts on the community. This study aimed to describe perceptions of the broader impacts of the NMP. Methods. In this qualitative study, semi-structured interviews were conducted with community leaders in various sectors of Prince George. The interviewer probed about perceived current and anticipated future impacts of the program, both positive and negative. A descriptive content analysis was performed. A conceptual framework of hypothesized impacts was created based on the literature and a model of neighbourhood social capital by Carpiano (2006). Findings. Comments were overwhelmingly positive. Impacts were described on education, health services, economy, politics, and media. Some reported negative impacts included tension between the NMP and other departments at UNBC, and a strain on health system resource capacity. Participants also reported that the NMP has impacted social capital in the region. Social capital, defined as the resources belonging to a network of individuals, was a pervasive theme. Impacts on social cohesion, various forms of social capital, access to social capital and outcomes of social capital are described. Conclusions. The full impact of the NMP will likely not be felt for at least a decade, as the program is still relatively new to Prince George. Findings suggest that an undergraduate medical education program can have pervasive impacts in an underserved community. Evaluation of the impact of such programs should be broad in scope. Findings also suggest that impacts of the program on other community sectors and on social capital may in fact lead to greater human capital gains than originally anticipated. A comprehensive communication strategy should be developed and maintained to ensure continued stakeholder support for the program. Next steps include identifying key quantifiable indicators of community impact to track changes in the community over time. / Medicine, Faculty of / Population and Public Health (SPPH), School of / Graduate
548

Relative influence of temperature and disturbance on vegetation dynamics in the Low Arctic : an investigation at multiple scales.

Lantz, Trevor Charles 11 1900 (has links)
Climate change will affect Arctic plant communities directly, by altering growth and recruitment, and indirectly, by increasing the frequency of natural disturbance. Since the structure of northern vegetation influences global climate, understanding both temperature and disturbance effects on vegetation is critical. Here, I investigate the influence of temperature and disturbance on Low Arctic vegetation at several spatio-temporal scales in the Mackenzie Delta Region, N.W.T. To disentangle the relative impact of temperature and disturbance on forest-tundra and tundra ecosystems, I sampled microenvironmental variability, plant community composition, and green alder abundance, growth, and reproduction on disturbed (burns and thaw slumps) and undisturbed sites across a regional temperature gradient. Disturbed areas showed increases in alder productivity, catkin production, and seed viability, as well as differences in plant community composition and microenvironment. The magnitude of plot-level responses to disturbance compared to variation across the temperature gradient suggests that in the short-term, increasing the frequency of disturbance may exert a stronger influence on tundra ecosystems than changes in temperature. At the plot level, increases in alder seed viability and recruitment at warmer sites point to the fine-scale mechanisms by which shrub abundance will change. To examine the relative influence of temperature and biophysical variables on landscape-level patterns of shrub dominance, I mapped Low Arctic vegetation using aerial photos. At this broader scale, correlations between temperature and the areal extent of shrub tundra suggest that warming will increase the dominance of shrub tundra. To assess the magnitude of changes in temperature and thaw slump activity, I analyzed climate records and mapped retrogressive thaw slumps using aerial photographs. An increase in thaw slump activity in recent decades, coincident with higher temperatures, suggests that continued warming will change the area affected by thermokarst disturbances like slumps. Taken together, my research indicates that the effects climate change will be magnified by shifts in the frequency of disturbance, initiating changes to Arctic vegetation with significant implications for global climate. My work also shows that to fully understand the influence of patch-landscape feedbacks on Arctic vegetation dynamics, the effects of disturbance must be examined across longer temporal and broader spatial scales. / Forestry, Faculty of / Graduate
549

Towards a methodology for identifying potential sites for cemeteries

Judge, Richard David Eadie January 2012 (has links)
Due to death being an extremely sensitive issue, the topic of cemeteries and associated environmental impacts is often left outside the mainstream environmental critique. However, this is a topic becoming more prevalent as the population numbers and the death rate increases, while the amount of available land decreases. Recent research has indicated that poorly sited cemeteries may pose a significant threat to groundwater resources with the consequential potential for severe health hazards. This has resulted in the need for a method of determining the acceptability of a given area for the establishment of a cemetery in a South African context. Cemeteries should be sited in such a way as to mitigate potential public health and safety concerns, minimise associated environmental impacts and provide a method of body disposal that is economically viable. This study therefore provides an integrated methodology to identify and assess a given area and rank a number of potential sites, ultimately determining a single cemetery site which proves to be acceptable for the establishment of a cemetery. Cemetery site selection should be based on the factors affecting the pollution potential of a proposed cemetery. These factors were identified and quantified based on research into the mechanisms of cemetery site pollution resulting in a number of fatal flaws and criteria deemed decisive when selecting a potential cemetery site. The assessment of a site with regards to these criteria and fatal flaws is undertaken through the use of GIS analysis software utilising data layers containing information on the site selection criteria, by investigating existing studies, literature or reports relating to the relevant area, or through field investigations. Although these criteria are vital when determining the specific characteristics of a site in terms of its pollution potential, a method of assessing a number of potential sites with regards to these criteria is vital. To this end, a multi-criteria ranking matrix has been developed, allowing for an objective method of assessing individual sites and thus indicating which sites are more suited for the establishment of a cemetery. The ranking matrix identifies a range of values for each criterion, therefore identifying a minimum and maximum allowable value. A site is then assessed with regards to these criteria in relation to the values identified in the ranking matrix. Each criteria is assigned a score according to the site conditions. Once the criteria for each site has been assessed and scored, the results can be tallied allowing the sites to be ranked according to which site proved to be the most acceptable for a cemetery based on the findings of the application of the site selection criteria. The methodology developed in this study is unique to previous studies in that it provides an integrated and staged approach to identifying, assessing and applying the criteria affecting the pollution potential of a cemetery. The methodology also provides a means of ranking a number of potential sites so to determine the most suitable. Furthermore, the criteria deemed as decisive in previous investigations were in most cases not quantified by the relevant authors, therefore leaving many of the criteria values up for interpretation. For this methodology to be affective, all criteria must be quantified therefore identifying maximum and minimum allowable limits for each. This study applies minimum and maximum allowable limits to these criteria, therefore aiding in the ranking process. The integrated methodology developed was then applied to a case study where by the effectiveness in identifying a number of potential cemetery sites could be tested. Subsequent to the application of this methodology to a case study, it was concluded that an additional two criteria, not identified in previous investigations, needed to be assessed to more adequately determine the suitability or otherwise of a site for a cemetery. Ultimately, twelve major criteria have been proposed for use as the basis of the methodology. The methodology and pertinent criteria proposed in this study should be compiled as a standard for planning authorities and consultants to use as a method of determining a number of potential environmentally sound cemetery sites.
550

The forced vibration of a partially delaminated beam

Menday, Roger January 1999 (has links)
The forced vibration of a partially delaminated structure such as an aircraft wing can result in catastrophic crack growth. In order to look at the underlying mechanism of the dynamics and failure of the material, a simplified model of a cantilever beam with a single delamination at its free end is considered. We investigate a number of aspects of this system, using mathematical models to gain insight into its behaviour.

Page generated in 0.1113 seconds