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  • 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.
261

Management practices to minimize volatile and dislodgeable foliar residues of turfgrass pesticides.

Carrier, Scott A. 01 January 2002 (has links) (PDF)
No description available.
262

Scatterometer Contamination Mitigation

Owen, Michael Paul 28 September 2010 (has links) (PDF)
Microwave scatterometers, which use radar backscatter measurements to infer the near-surface wind vector, are unique in their ability to monitor global wind vectors at high resolutions. However, scatterometer observations which are contaminated by land proximity or rain events produce wind estimates which have increased bias and variability, making them unreliable for many applications. Fortunately, the effects of these sources of contamination can be mitigated. Land contamination of backscatter measurements occurs when land partially fills the antenna illumination area. This reduces and masks the wind-induced backscatter signal. Land contamination is mitigated by quantifying the amount of contamination in a single observation using a metric referred to as the land contribution ratio (LCR). LCR levels which give rise to inadmissible levels of error in the wind estimates are determined and used to discard land-contaminated observations. Using this method results in contamination-free wind estimates which can be made as close to the coast as 5 km, an improvement of 25 km compared to previous methods. Rain contamination of scatterometer observations results from rain-induced scattering effects which modify the wind-induced backscatter. Rain backscatter effects are modeled phenomenologically to assess the impact of rain on the observed backscatter. Given the backscatter effects of wind and rain, there are three estimators: wind-only (WO), simultaneous wind and rain (SWR) and rain-only (RO), which have optimal performance in different wind and rain conditions. Rain contamination of wind estimates is mitigated using a new Bayes estimator selection (BES) technique which optimally selects WO, SWR, or RO estimates as they are most appropriate. BES is a novel adaptation of Bayes decision theory to operate on parameter estimates which may have different dimensions. The BES concept is extended to include prior selection and noise reduction techniques which generalizes BES to a wider variety of wind fields and further increase wind estimate accuracy. Overall, BES has wind estimation performance which surpasses that of either the WO or SWR wind estimates individually, and also provides a viable rain-impact flag.
263

A Holistic Framework for Evaluating Gigatonne Scale Geological CO2 Storage in the Alberta Oil Sands: Physics, Policy, and Economics / Carbon Capture and Storage in the Alberta Oil Sands

Zhao, Yu Hao January 2023 (has links)
An increasing number of countries worldwide have made commitments in recent years to reduce emissions with the goal of limiting global temperature increases to 1.5-2 °C. Carbon capture and storage (CCS) is capable of significantly reducing anthropogenic carbon dioxide (CO2) emissions and is an important tool in the effort to mitigate climate change. The ability of CCS to sequester emissions at a large scale makes it suitable to particularly emission-intensive sectors, such as the oil and gas sector in Canada. Many factors must be considered holistically to ensure the long-term success of large-scale CCS, such as the availability of emission sources, the design of a CO2 transportation network, the availability and capacity of suitable storage sites, the long-term fate of the injected CO2, the economic viability of the system, and the overall policy environment. Previous studies have considered these factors in demonstrating the viability of CCS in Alberta but have not done so holistically. We take a holistic approach in designing a large-scale integrated CCS system which includes CO2 capture from a hub of 10 large oil sands emitters, transport via a pipeline network, and permanent sequestration in the Nisku and Wabamun saline formations. We use a logistic model to forecast long-term oil sands hydrocarbon production and annual emissions, and ensure that all of the capturable emissions can be stored safely without exceeding pressure limits by modeling the long-term pressure evolution. The injected CO2 will be fully trapped in 6100-11000 years without migrating past the minimum storage depth. We calculate the capital expenditures for the pipeline and injection well components of the system and show that the amount of funding required is reasonable under the umbrella of federal infrastructure funding. This provides a comprehensive framework to ensure the long-term success of future CCS projects. / Thesis / Master of Applied Science (MASc) / The global community has increasingly recognized the importance of greenhouse gas emission reductions in the effort to mitigate climate change. Carbon capture and storage (CCS) is a technology that, with widespread use at a large scale, has the potential to significantly reduce emissions. However, due to the high cost and lengthy time commitment required, many factors ranging from emission sources to storage capacity to financial considerations must be accounted for to ensure the success of a CCS system. Here, we show that a large-scale CCS system in Alberta is viable and the captured CO2 can be safely stored in the long term. This framework can be used to ensure the success of future CCS projects.
264

Micrometeoroid Fluence Variation in Critical Orbits Due to Asteroid Disruption

Aretskin-Hariton, Eliot Dan 01 June 2013 (has links) (PDF)
Micrometeoroids and orbital debris (MMOD) is a growing issue with international importance. Micrometeoroids are naturally occurring fragments of rock and dusk that exist throughout the solar system. Orbital debris is human made material like rocket bodies, paint flakes, and the effluent of spacecraft collisions. Even small MMOD particles on the order of 1 cm in diameter have the potential to destroy critical spacecraft systems. Because of this, MMOD is a threat to all spacecraft in orbit. Even governments that most sternly oppose US international policy have a stake when it comes to minimizing MMOD flux. Space-based assets are essential to support the growing demand for high-capacity communications networks around the world. These networks support services that civilian and military users have grown accustomed to using on a daily basis: Global Positioning System (GPS), Satellite Radio, Internet Backhaul, Unmanned Areal Vehicles (UAVs), and Reconnaissance Satellites [Figure \ref{figure:skynet}]. A sudden loss of these services could degrade the warfighter's capabilities and cripple commercial enterprises that rely on these technologies. Manned space efforts like the International Space Station (ISS) could also suffer as a result of increased MMOD flux.
265

Investigation of Microalgae Growth Kinetics Using Coal-Fired Flue Gas as a Carbon Source

Brooker, Bryan Daniel 01 June 2011 (has links) (PDF)
ABSTRACT Investigation of Microalgae Growth Kinetics using Coal-Fired Flue Gas as a Carbon Source Bryan Daniel Brooker Energy related carbon dioxide (CO2) emissions make up the majority of the United States’ greenhouse gas emissions. Emissions must be alleviated to reduce the effects of global climate change. Microalgae cultivation sequesters CO2 while producing biomass. Algal biomass can provide a renewable feedstock for biofuel and electricity production, and ingredients for pharmaceuticals, nutraceuticals, pigments and cosmetics. Utilizing microalgae to mitigate CO2 emissions encourages energy independence by providing a feedstock for biofuels and offers other potentially profitable avenues for the uses of biomass. This study focused on investigating the algal growth kinetics of microalgae cultivated with artificial coal-fired flue gas. Two algal strains, Chlorella vulgaris and Tetraselmis sp. were cultivated in lab scale photobioreactors to assess the feasibility of using flue gas as a carbon source for microalgae growth. The microalgae growth kinetics were compared between flue gas and pure CO2 treatments for each algal strain. Both microalgae species were able to grow under flue gas dosing. The differences in growth characteristics for Chlorella were statistically insignificant between the two gas dosing treatments. Tetraselmis yielded identical maximum specific growth rates among the two gas treatments, while the biomass production was greater using CO2. At a 95% confidence interval, the difference in biomass production between the gas treatments ranged from 45 to 225 mg/L. The decrease in biomass production for Tetraselmis was the only sign of growth inhibition from flue gas. Overall, Chlorella vulgaris and Tetraselmis sp. are capable of fixating CO2 from coal-fired flue gas.
266

Integrating Solar Energy and Local Government Resilience Planning

Schmidt, Stephan Wayne 01 June 2014 (has links) (PDF)
Resilience and solar energy are separately growing in popularity for urban planners and similar professionals. This project links the two discrete terms together and examines the extent to which solar energy can improve local government resilience efforts. It includes a detailed literature review of both topics, as well as the methodology and findings related to a survey and interviews of local government officials and key stakeholders across the country related to hazard mitigation and energy assurance planning. This research finds that integrating the use of solar energy can improve local government resilience efforts related to mitigation, preparedness, response and recovery activities in the following ways: by being incorporated into hazard mitigation strategies as a means to maintain critical operations, thereby reducing loss of life and property; by being utilized in comprehensive planning efforts to increase capacity and decrease reliance and stress upon the grid, thereby reducing the likelihood of blackout events; by being used in tandem with backup storage systems as an integral part of energy assurance planning, which can help ensure critical functions continue in times of grid outage; by being used to provide power for response activities such as water purification, medicine storage and device charging; and by being used as an integral part of rebuilding communities in a more environmentally-conscious manner. The result of the research is a document entitled Solar Energy & Resilience Planning: a practical guide for local governments, a guidebook for local government officials wishing to have more information about incorporating solar energy into current resilience initiatives; it is included at the end of the report as Appendix C.
267

Using the Papathoma Tsunami Vulnerability Assessment Model to Forcast Probable Impacts, and Planning Implications, of a 500-Year Tsunami in Cayucos, California

Marshall, Andrew Robert 01 June 2015 (has links) (PDF)
This report focuses on using the Papathoma Tsunami Vulnerability Assessment Model (PTVA) to demonstrate the vulnerability of Cayucos to a 500-year tsunami, and using the results to inform specific planning recommendations. By modeling inundation with GIS and analyzing building attributes via the PTVA model, this study has gone beyond any previous vulnerability assessments of Cayucos. Findings include: delineation of the most vulnerable areas, estimates of numbers of lost civic buildings, commercial buildings and houses, as well as estimates of people displaced from tsunami damaged homes. The report goes on to discuss what mitigation measures are in place and what further specific steps could be taken to ensure the long term sustainability of the town and help reduce future tsunami losses. Cayucos is a small coastal town in San Luis Obispo County, California; popular with tourists and locals for its beach, pier, and downtown. Intense coastal development and low lying topography makes Cayucos among the most tsunami vulnerable communities in the county. Many civic and economically important buildings, as well as homes, are within the 500-year tsunami inundation area. In the absence of fully developed, and accessible assessment tools like FEMA’s HAZUS tsunami program; local planners have had only basic information to assess the community’s tsunami vulnerability. The Papathoma Tsunami Vulnerability Assessment Model (PTVA) is a method that uses available tsunami runup estimations and field data collection to produce a detailed assessment of individual building survivability and overall community vulnerability.
268

Performance of Resin Injection Ground Improvement in Silty Sand Based on Blast-Induced Liquefaction Testing in Christchurch, New Zealand

Blake, David Harold 26 April 2022 (has links)
Polyurethane resin injection is a treatment being considered as a replacement for traditional methods of ground improvement. It has been used to re-level foundations and concrete slabs that have settled over time. Additional claimed benefits of the treatment have been noted recently, including improved factors of safety against soil liquefaction and reduced earthquake-induced settlements. To investigate the capability of the polyurethane resin injection treatment to mitigate liquefaction, two full-scale blast liquefaction tests were performed; one test was conducted in an improved panel (IP), an 8 m circular area treated with the polyurethane resin in a 1.2 m triangular grid from a depth of 1 to 6 m, and another test in an untreated 8 m circular area, the natural panel (NP). Each blast test was severe enough to produce liquefaction (ru ≈1.0) in the respective panel, with blast-induced settlements in the range of 70 to 80 mm. Despite similar levels of ground-surface settlement in the IP and NP, settlement within the top 6 m of the IP was about half that of the NP. A CPT-based predicted settlement for each panel was employed using the Zhang et al. (2002) methodology. Good correlation was found between the observed settlements and predicted settlements in both panels. Differential settlements across the panels were calculated based on ground-based lidar surveys, with a reduction of 42 to 49% between the IP and NP. The measured total and differential settlements following resin injection were at the bottom of the range observed in blast tests on a variety of shallow ground improvement methods conducted by the New Zealand Earthquake Commission in 2013. The persistence of the polyurethane resin injection ground improvement three years following its installation was indicated by the lasting increase of fundamental in situ test parameters. The results of the study indicate that resin injection is a viable method of ground improvement to reduce liquefaction-induced settlements by creating a stiffer surficial crust.
269

Educational Intervention to Mitigate the Effects of Bullying in the Student Nurse Population

Rutherford, Dawna E. 22 October 2020 (has links)
No description available.
270

BLAST DAMAGE MITIGATION IN SUBMERGED SYSTEMS. PHASE I: INTERNAL EXPLOSION

Khalifa, Yasser 11 1900 (has links)
This thesis is focused on quantifying the dynamic performance of lightweight metal sandwich systems under confined explosions, where this effort represents the first of a multi-phase comprehensive research program that is focused on developing blast damage mitigation techniques in submerged structures. A confined explosion occurrence inside such facilities may lead to paralyzing all operations depending on the functions of the affected sections. Subsequently, using sacrificial cladding placed as a physical barrier over critical components that might be vulnerable to a potential explosion is considered to be an effective blast damage mitigation technique. Furthermore, sandwich panels can be an ideal system to be used as sacrificial cladding, as it can be manufactured to possess high stiffness-to-weight ratio and superior energy absorption capabilities. Consequently, an experimental program was performed to investigate the performance of lightweight cold-formed steel sandwich panels under both quasi-static loads and confined explosions, where a total of fifty-seven sandwich panels were tested, considering various core configurations, different core sheet thickness, and different blast load intensity levels. The American ASCE/SEI 59-11 and The Canadian CSA/ S850-12 blast design standards predict the dynamic response of a structure component based on the static resistance function by applying dynamic increase factors. Subsequently, the static resistance functions for the proposed panel configurations were investigated experimentally and compared with the introduced analytical model, in order to quantify accurately the inelastic panel response. The quasi-static test program was performed in two stages, where the first included eighteen single layer core sandwich panels, which represented longitudinal and transverse corrugated core configurations. The results of the first stage configurations demonstrated an efficient strength and stiffness, but showed a lack in energy absorption capabilities and ductility capacity. Therefore, in the second stage, different core configurations were developed, including twenty-one panels representing Bi-directional and X-core double layered core configurations and its counterpart Uni-directional single layer core configuration. The results of the second stage demonstrated an enhancement in the ductility and energy absorption capabilities compared to the configurations tested in the first stage. The residual deformations and failure modes demonstrated were assessed and discussed in details, where web crippling, local buckling and global buckling induced by shear or flexurewere determined. In general the static resistance functions for each tested panel were used to quantify the panels’ yield loads, ultimate capacities, and corresponding displacement levels. Moreover, the influences of both the core configuration and the core sheet thickness on the panels’ stiffness, ductility levels and energy absorption were quantified. Based on the conclusions of the static testing and considering the ductility, capability of energy absorption, and the behavior beyond the elastic zone, two different core configurations were chosen to be tested under confined explosions. Eighteen panels were tested in a cylindrical shape blast chamber representing a typical submerged structure under different scaled distances ranged from 2.82 to 1.09 m/kg1/3, in order to demonstrate different damage state levels in accordance with the blast design standards (ASCE/SEI 59-11, CSA/ S850-12). In the blast testing results, the incident and reflected pressure time histories of the blast wave were measured, while the modified Friedlander equation was used to fit the first positive phase of the reflected pressure histories. In addition, the displacement response histories of the back face of the tested panels were recorded. The measured values of peak incident pressure, peak reflected pressure, incident impulse and the reflected impulse were compared to the predicted values using ConWep (Hyde 1990) considering the spherical explosion, and have shown a good agreement. Furthermore, the failure modes and the post blast damage were determined and compared to the static observations. In order to complement the experimental program, a nonlinear inelastic single degree of freedom model was developed in order to predict the dynamic response of the sandwich panels. The model used the recorded blast load and the static resistance while applying the dynamic increase factors recommended by the standards (ASCE/SEI 59-11, CSA/ S850-12). The model results were in a good agreement with the experimental data. Furthermore, the different ductility and support rotation values obtained experimentally and predicted analytically were related to the different damage levels specified by blast standards. Finally, the influence of sandwich panel core configuration on the dynamic blast response of the tested sandwich panels was discussed. / Thesis / Doctor of Philosophy (PhD)

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