• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 110
  • Tagged with
  • 257
  • 257
  • 257
  • 257
  • 115
  • 94
  • 89
  • 63
  • 47
  • 41
  • 36
  • 36
  • 34
  • 32
  • 29
  • 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.
81

The Automated Environmental Information and Design Analysis System

Gavaras, George William 01 January 1978 (has links)
No description available.
82

Putting the spin on wind energy: risk management issues associated with wind energy project development in Australia

Finlay-Jones, Richard Unknown Date (has links)
The debate on global warming is over (Stix, 2006 p24). The global community must now find ways to reduce greenhouse emissions, particularly from energy generation. Wind energy provides one of the potential solutions to generate renewable energy without creating harmful greenhouse gases. Wind energy is the fastest growing energy generation industry globally (‘Operating wind power capacity' 2006a). This rapid growth is being driven by increasing global energy demand, commitment from governments globally to international agreements including the Kyoto Protocol (UNFCCC 1997) to reduce the emission of greenhouse gases, as well as individual country commitments to mandatory renewable energy targets. Australia, whilst being a signatory to the United Nations Framework Convention on Climate Change (UNFCCC) commitment to reduce greenhouse gas emissions, has so far failed to ratify the Kyoto Protocol. In Australia, wind energy development to date has been driven primarily by the development of the Mandatory Renewable Energy Target (MRET) under the Renewable Energy (Electricity) Act 2000. This requires a commitment to 2% of total electricity generation (9,500GW) to be derived from renewable energy sources by the year 2010 (Warwryk, undated). It is now understood, that the current federal obligation to renewable energy is now oversubscribed, and consequently the likelihood of further wind energy projects being developed is highly limited (Brazzale 2005). External to the government commitment to renewable energy, the development of wind energy projects requires a range of inputs including, but not limited to; an understanding of the wind resource, security of land, access to suitable electricity transmission grid, a market for the electricity, access to suitable technology and a level of community support. Whilst the literature related to project management and risk management is extensive, the literature related to the risks associated with wind energy development in Australia is limited. This research then seeks to fill a void that asks the question; How can project managers minimise the risk associated with wind energy developments in Australia? To investigate this research problem, comparative case study analysis was adopted as a methodology utilising a structured interview process of project managers responsible for the development of 8 Australian wind energy projects. This research shows that the greatest risk to Australian projects is the lack of security associated with the current federal legislation and the consequent loss of market value of the power from wind energy projects. A number of additional primary and secondary risks are identified by the interview participants, and the research is able to draw out three common themes of risk management strategies. These three themes were categorised as conservatism, due diligence and proactivism. This study contributes to the research associated with project management, risk management and wind energy development. This insight into the Australian wind energy industry provides policy makers, educators and stakeholders with information to assist in improving the political, economic and social environment for further wind energy development, in order to mitigate against further greenhouse gas emission and combat global warming.
83

Modelling dynamics including recruitment, growth and mortality for sustainable management in uneven-aged mixed-species rainforests

Kariuki, Maina Unknown Date (has links)
Changes in species abundance and richness, stand structure, and species responses to habitat characteristics including disturbance intensity, were investigated in 28 permanent sample plots (PSP) covering a total area of about 6.2 hectares of subtropical rainforests in north-east New South Wales, Australia. The disturbance that occurred over 36 years previously varied from unlogged (controls), through single-tree selection (light), moderate selection and repeated single-tree selection to intensive (heavy) logging. Multivariate and univariate approaches were used to investigate changes in various plant groups, including all vascular plants, regenerating species (trees and understorey species > 1.3 m in height and < 10 cm diameter at 1.3 m above the ground level (dbh)), juvenile trees (regenerating species capable of attaining at least 10 cm dbh), and trees ¡Ý 10 cm dbh. In addition, dynamic parameters (recruitment, growth and mortality) were estimated using hierarchical multilevel modelling and parameter estimates used to simulate behaviour of the subtropical rainforest tree species in unlogged and logged stands, both within and beyond the range of available data.Chronological post-disturbance responses and changes in species abundance and richness as well as stand structure for trees ¡Ý 10 cm dbh were investigated using 20 PSP in a bid to better understand rainforest post-disturbance regeneration. The results portrayed minor and gradual ecological changes in the undisturbed controls analogous with natural forest dynamics where the changes were not significant. In logged sites, initial gradual changes were followed with more rapid and significant changes.In both unlogged and logged stands, the changes proceeded through three clearly identifiable stages. The first two stages lasted between 5 and 15 years each. In the initial stage, the number of individuals decreased in species with high frequency mainly in the shade tolerant species, with little or no change in species richness. In the second stage, species abundance and richness changed due to localised species turnover, replacement and losses with very little recruitment, and the numbers of both speciesand individuals declined to minima. In the third stage, due to recruitment beyond the 10 cm dbh, the net loss of species and trees ¡Ý 10 cm dbh were halted and reversed, and species diversity and abundance began to return to pre-disturbance levels.Species abundance and diversity for both shade tolerant and intolerant species in less intensively logged sites (single-tree selection logging) have recovered to levels comparable with that observed in the controls, but more intensively logged sites have not recovered to similar levels. Increased logging intensity was associated with increased and decreased densities in the shade intolerant and ¨Ctolerant species respectively. It was evident that stand structure in logged sites had yet to recover to levels comparable with that of unlogged controls. It appears the restoration of floristic diversity to levels similar to that of intact primary forest takes considerably less time than structural recovery. Changes in regeneration patterns in a subtropical rainforest in north-east New South Wales were investigated for a 13-year period during the 3rd and 4th decades following repeated single-tree selection logging. Multivariate and univariate analyses results showed that there were no significant differences in floristic assemblages within and between censuses; however, two contrasting trends of changes in plant groups were detected. In trees ¡Ý 10 cm dbh, the stem density and species richness increased in shade tolerant group, and while stem density increased in the shade intolerant group, species richness decreased during the study period. Amongst smaller sized species including trees (< 10 cm dbh), a general decrease in species richness was observed along with significant changes in stem densities (P = 0.03) with the number of individuals in the shade tolerant species increasing, while that of both shade intolerant and vine species decreased. Excluding the vines and understorey species from the broader regenerating species group, revealed a decrease in species richness in juvenile canopy tree, and a significant change in densities (P = 0.004) with the number of individuals in shade tolerant increasing, while that of shade intolerant trees decreased. A comparison between the canopy trees ¡Ý 10 cm dbh and juvenile canopy trees group showed that these groups were tending towards similar floristic assemblages. These results suggest gradual replacement of shade intolerant by shade tolerant species as stands were tending toward later stages of recovery within the regeneration. The results also show that the inclusion of regenerating species in long-term studies is both complementary to the larger plant component and more revealing of both trends and changes.Species-specific estimates of shade tolerance and size structure at maturity derived from observations on 23 plots were used to intuitively group 277 vascular plant species into 3 main groups including full floristic (all together), shade tolerant and intolerant groups. The shade tolerant and intolerant groups were further grouped into smaller plants groups depending on the development stage and maximum size at maturity. These groups included regenerating species, juvenile trees, and trees ¡Ý 10 cm dbh. Multivariate analyses of these nominated groups revealed that floristic assemblages were significantly associated with environmental gradients based on simple site characteristics.At the landscape (larger) scale, the floristic assemblages were significantly different between low (200-400), mid (400-700) and high altitude (over 700 meters above sea level). In addition, abundance of shade tolerant species including Doryphora sassafras Endl, Orites excelsa R.Br and Caldcluvia paniculosa (F.Muell) Hoogland was positively correlated with the altitudinal gradient. At the smaller (local) scale, intensively logged sites where large gaps were created had recovered their species richness, but effects of past logging were evident in trees ¡Ý 10 cm dbh, especially trees greater than 50 cm dbh where species abundance in shade tolerant decreased significantly. Less intensively logged sites at mid altitude where a few stems were removed had recovered their species richness in respect to trees ¡Ý 10 cm dbh, but the small gaps created may have healed quickly for appreciable regeneration response to occur, as juvenile trees component was significantly different to that of the (unlogged) controls.The abundance of shade intolerant and juvenile shade tolerant tree species increased in concert with levels of disturbance and abundance of shade intolerant species such as Duboisia myoporoides R.Br, Acacia melanoxylon R.Br, Rubus moorei F.Muell and R. hilli F.Muell was positively correlated with the disturbance gradient. Increase in number of individuals of certain tree species was positively correlated with both disturbance intensity and topography (mid slope through lower slope to creek/gully), but negatively correlated with aspect (NE - NW). We concluded that logged sites are yet to recover their pre-logging stand structure and rainforest tree species were found in sites where favourable recruitment and growth conditions were the encountered. These results show that logged sites had not yet regenerated to the pre-logging stand structure. They also show that habitat characteristics including history of disturbance and topography can influence the floristic assemblages in the sub-tropical rainforests at both the small (local) and large (geographic) scales. This supports the environmental control model that states ¡°species are found at sites where they encounter favourable living conditions¡±. Site characteristics as surrogate for some of these favourable living conditions were identified as useful potential variables to investigate the rainforest dynamic parameters (growth, recruitment and mortality) in both logged and unlogged stands.A quantitative model was developed using over 3 decades of data to describe and simulate the dynamics including recruitment, growth and mortality in unlogged stands and others subjected to different silvicultural regimes in uneven-aged mixed-species subtropical rainforests of north-eastern New South Wales. Hierarchical multilevel regression analyses including Poisson, Binomial and multinomial logit regression were used to estimate the rainforest dynamic parameters based on the assumption that trees perform differently in space and time, thus there are variations at both the plot and tree by measurement levels.Variations at the tree level required the botanical identity of trees to species level, and then the species-specific size at maturity and shade tolerance were used to classify species into 5 groups, each consisting of species with similar ecological characteristics. These groups were labelled as emergent and shade tolerant main canopy, shade tolerant mid canopy, shade tolerant understoreys, moderate shade tolerant and persistent, and shade intolerant pioneer tree species. Significant variables at the plot level including site characteristics such as topography (elevation, slope and aspect), and past disturbance were used as explanatory variables in species group models. The final model is as a classical matrix management-oriented model with an ecological touch and maximum size-dependent parameters of ingrowth and outgrowth. The model provides a tool to simulate stand performance after logging and to assess silvicultural prescriptions before they are applied in these types of forests.The simulations indicate that full recovery following a logging intensity where 47% of the overstorey basal area is removed with a checkerboard of logged and unlogged patches (group selection) on a 120-year cycle could enable sustainable timber production without compromising the ecological integrity in these forests. Following single-tree selection (33%), recovery takes about 150 years, and more intensive harvesting practices where 50-78% overstorey basal area is removed may take 180-220 years to recover. Pre-harvest climber cutting coupled with poisoning of non-timber species followed by intensive logging of merchantable trees would allow logging on a 300-year cycle. Shorter logging cycles may lead to changes in the forest structure and floristic composition where the overall species density is low with higher density of shade intolerant species.
84

Cougar Predation Behavior in North-Central Utah

Mitchell, Dustin L. 01 May 2013 (has links)
Cougar (Puma concolor) predation has been identified as being one of several factors contributing to the decline of mule deer (Odocoileus hemionus) throughout the Western United States. In order to better understand how these elusive felines utilize their surroundings and prey, I examined and analyzed cougar predation behavior in North-Central Utah, using global positioning systems (GPS) data from 2002-2010. Twenty-three cougars were fitted with GPS collars and monitored for prey caching behavior. In total 775 potential cache sites were visited and 546 prey remains found. Mule deer comprised the majority of prey at cougar cache sites, but 11 other species were also found. Collectively, adult female mule deer were killed more than any other demographic class. Proportionally there was no difference in the sex or age class of deer killed by cougars in three different population segments, but seasonal differences were found in the number of kills made between cougar groups. Female cougars with kittens had a higher predation rate than males or solitary females, and seasonally more kills were made in the winter vs. summer. Cougars spent an average of 3.3 days on deer kills, and 6.2 days on elk kills. Habitat analyses suggested that cougars preferentially used Gambel oak (Quercus gambelii) over other land cover types when caching prey, as well as selected unburned over burned areas for caching and foraging on prey. These results suggest that cougars utilize dense stands of vegetation cover when stalking and concealing their prey. Wildlife managers may want to consider the use of prescribed burns in areas of high cougar predation on mule deer. This habitat manipulation tool could simultaneously help mule deer populations by reducing the percent of stalking cover afforded to cougars when attempting to kill prey, along with increasing nutrient levels of newly burned foliage and allow for an increased diversity in forb and shrub species available to mule deer.
85

Sustaining Rural Economies with Wind Development

Van Oss, Eric J. 01 January 2010 (has links)
This paper discusses the effects of wind development in rural areas. Areas of focus include: direct job creation, indirect job creation, tax revenue and government policies. The effects of state and federal renewable energy policies are discussed and well as the impacts to rural economies.
86

Aquculture and Deforestation in the Peruvian Amazon

Halpern, Gator 01 May 2012 (has links)
This study examines whether aquaculture has the potential to reduce deforestation in the Peruvian Amazon. The natural resources of the Peruvian Amazon are subject to extreme pressures due to increases in subsistence farming, cattle ranching, and logging in the region. The resulting loss of biodiversity has affected the delicate soil balance that is characteristic of the Amazon, and has contributed to water pollution as well as erosion (Guerra et al. 2001). One of the highest rates of deforestation in the Amazon basin can be found at the foothills of the eastern Andes (Lepers et al. 2005), which includes the area in this study, located in the Peruvian state of Amazonas. In this part of the Amazon, deforestation is mainly caused by small-scale subsistence agriculture (Achard et al. 1998) such as that found in the communities of Condorcanqui. Fishing is an essential part of the socio-economic system that functions in the Peruvian Amazon. Fish meat is the most important source of animal protein in the Amazon, and the main generator of cash for indigenous people (McDaniel, 1997). However, freshwater Amazonian fisheries have been subject to extreme overexploitation in the past few decades (Rainforest Conservation Fund, 1999). Boats with technological equipment and large-scale capacities have threatened stocks in local rivers and oxbow lakes, which has affected the ability of small-scale, native fisherman to support themselves (Rainforest Conservation Fund, 1999). The Instituto de Investigaciones de la Amazonia Peruana (IIAP) has assisted the development of fish farming in the Condorcanqui region as a way to augment diets and decrease the ecological impact of subsistence farming. Fish farming can also be seen as a way to substitute for the loss of traditional river fishing. IIAP has become the leading governmental organization in fisheries research and aquaculture in the Peruvian Amazon, and works to provide native-species fingerlings, and educational courses to native aquaculturists. This study surveys the subsistence villages along road and river communities to determine the impact of fish farming on deforestation in the Condorcanqui region. This region is populated by small communities of indigenous Awajún and Wampí tribesmen, who practice subsistence agriculture. Data was collected from a sample of 184 families in ten different communities. Five of the villages were situated along the banks of the Nieva or Santiago river systems, while the other five were accessible by road, travelling southwest from the town of Santa Maria de Nieva. Data was collected with the assistance of the Research Institute of the Peruvian Amazon (IIAP), which provided a guide who had relations with all of the communities. All of the families in the sample practice subsistence agriculture, while 104 of the respondents supplement their agricultural crops with fish from aquaculture ponds integrated into their farmland. The participants answered a range of questions about the size of their farms, and the productivity of their land. We use a variety of regression-based approaches to determine how incorporating aquaculture into subsistence farmlands affects deforestation rates after controlling for socioeconomic and farm characteristics. Our study suggests that an extra square meter of aquaculture reduces the area deforested for crops on approximately a one for one basis. However, aquaculture should maintain its productivity for much longer than cropping, as it does not depend on soils whose fertility can be exhausted in a few years. Our simulations, based on our survey results, indicate that over time aquaculture should reduce deforestation significantly, especially in areas where soils provide only a few years of subsistence crops. These should be regarded as interesting but preliminary results. Because we used a convenience-based sampling approach, our results could be affected by selection bias. In addition, we do not have enough information to test whether selection bias in the implementation of fish farming affect our results. Therefore, these results suggest that aquaculture could be useful in limiting deforestation, but additional work should use experimental methods or more in-depth surveys to measure the effect of aquaculture on deforestation.
87

Sustainability Reporting At Higher Education Institutions

Heilmayr, Robert 01 January 2006 (has links)
Multiple declarations, governmental and non-profit organizations and universities have issued a call for proper reporting of social and environmental impacts and initiatives within academia. Such reporting can increase awareness of environmental and social impacts, encourage development of sustainable policy and build a campus culture more committed to sustainability. Sustainability reporting at Higher Education Institutions (HEIs) has the added benefit of being a powerful teaching aid. This paper follows multiple lines of inquiry in order to determine whether HEIs are taking advantage of the opportunities afforded by sustainability reporting. The analysis evaluates the history of sustainability reporting at HEIs and compares the practices of HEIs to those in other sectors. We use the Pacific Sustainability Index to methodically evaluate and rank the social and environmental reporting of 20 HEIs. We find that sustainability reporting is generally less rigorous in academia than other industries. The analysis emphasizes the need for greater institutional support for sustainability reporting at HEIs.
88

Ensuring Our Future or Sowing the Seeds of Our Own Destruction? Crop Insurance and Water Use in Texas

Shapiro, Michael 01 January 2015 (has links)
Agriculture is the largest consumer of water in the United States. Policies that affect agriculture therefore have the potential to have a large effect on the overall use of water. Crop insurance is one such policy, which was found to significantly increase water use in the state of Texas. Much, but not all of this effect can be explained by an increase in planting density, and results vary widely by crop and by region.
89

Putting the spin on wind energy: risk management issues associated with wind energy project development in Australia

Finlay-Jones, Richard Unknown Date (has links)
The debate on global warming is over (Stix, 2006 p24). The global community must now find ways to reduce greenhouse emissions, particularly from energy generation. Wind energy provides one of the potential solutions to generate renewable energy without creating harmful greenhouse gases. Wind energy is the fastest growing energy generation industry globally (‘Operating wind power capacity' 2006a). This rapid growth is being driven by increasing global energy demand, commitment from governments globally to international agreements including the Kyoto Protocol (UNFCCC 1997) to reduce the emission of greenhouse gases, as well as individual country commitments to mandatory renewable energy targets. Australia, whilst being a signatory to the United Nations Framework Convention on Climate Change (UNFCCC) commitment to reduce greenhouse gas emissions, has so far failed to ratify the Kyoto Protocol. In Australia, wind energy development to date has been driven primarily by the development of the Mandatory Renewable Energy Target (MRET) under the Renewable Energy (Electricity) Act 2000. This requires a commitment to 2% of total electricity generation (9,500GW) to be derived from renewable energy sources by the year 2010 (Warwryk, undated). It is now understood, that the current federal obligation to renewable energy is now oversubscribed, and consequently the likelihood of further wind energy projects being developed is highly limited (Brazzale 2005). External to the government commitment to renewable energy, the development of wind energy projects requires a range of inputs including, but not limited to; an understanding of the wind resource, security of land, access to suitable electricity transmission grid, a market for the electricity, access to suitable technology and a level of community support. Whilst the literature related to project management and risk management is extensive, the literature related to the risks associated with wind energy development in Australia is limited. This research then seeks to fill a void that asks the question; How can project managers minimise the risk associated with wind energy developments in Australia? To investigate this research problem, comparative case study analysis was adopted as a methodology utilising a structured interview process of project managers responsible for the development of 8 Australian wind energy projects. This research shows that the greatest risk to Australian projects is the lack of security associated with the current federal legislation and the consequent loss of market value of the power from wind energy projects. A number of additional primary and secondary risks are identified by the interview participants, and the research is able to draw out three common themes of risk management strategies. These three themes were categorised as conservatism, due diligence and proactivism. This study contributes to the research associated with project management, risk management and wind energy development. This insight into the Australian wind energy industry provides policy makers, educators and stakeholders with information to assist in improving the political, economic and social environment for further wind energy development, in order to mitigate against further greenhouse gas emission and combat global warming.
90

Putting the spin on wind energy: risk management issues associated with wind energy project development in Australia

Finlay-Jones, Richard Unknown Date (has links)
The debate on global warming is over (Stix, 2006 p24). The global community must now find ways to reduce greenhouse emissions, particularly from energy generation. Wind energy provides one of the potential solutions to generate renewable energy without creating harmful greenhouse gases. Wind energy is the fastest growing energy generation industry globally (‘Operating wind power capacity' 2006a). This rapid growth is being driven by increasing global energy demand, commitment from governments globally to international agreements including the Kyoto Protocol (UNFCCC 1997) to reduce the emission of greenhouse gases, as well as individual country commitments to mandatory renewable energy targets. Australia, whilst being a signatory to the United Nations Framework Convention on Climate Change (UNFCCC) commitment to reduce greenhouse gas emissions, has so far failed to ratify the Kyoto Protocol. In Australia, wind energy development to date has been driven primarily by the development of the Mandatory Renewable Energy Target (MRET) under the Renewable Energy (Electricity) Act 2000. This requires a commitment to 2% of total electricity generation (9,500GW) to be derived from renewable energy sources by the year 2010 (Warwryk, undated). It is now understood, that the current federal obligation to renewable energy is now oversubscribed, and consequently the likelihood of further wind energy projects being developed is highly limited (Brazzale 2005). External to the government commitment to renewable energy, the development of wind energy projects requires a range of inputs including, but not limited to; an understanding of the wind resource, security of land, access to suitable electricity transmission grid, a market for the electricity, access to suitable technology and a level of community support. Whilst the literature related to project management and risk management is extensive, the literature related to the risks associated with wind energy development in Australia is limited. This research then seeks to fill a void that asks the question; How can project managers minimise the risk associated with wind energy developments in Australia? To investigate this research problem, comparative case study analysis was adopted as a methodology utilising a structured interview process of project managers responsible for the development of 8 Australian wind energy projects. This research shows that the greatest risk to Australian projects is the lack of security associated with the current federal legislation and the consequent loss of market value of the power from wind energy projects. A number of additional primary and secondary risks are identified by the interview participants, and the research is able to draw out three common themes of risk management strategies. These three themes were categorised as conservatism, due diligence and proactivism. This study contributes to the research associated with project management, risk management and wind energy development. This insight into the Australian wind energy industry provides policy makers, educators and stakeholders with information to assist in improving the political, economic and social environment for further wind energy development, in order to mitigate against further greenhouse gas emission and combat global warming.

Page generated in 0.1165 seconds