Matching Items (21)
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- All Subjects: Ecology
- Creators: School of Sustainability
- Creators: Hall, Sharon
- Resource Type: Text
- Status: Published
Description
Defines the concept of the arcology as conceived by architect Paolo Soleri. Arcology combines "architecture" and "ecology" and explores a visionary notion of a self-contained urban community that has agricultural, commercial, and residential facilities under one roof. Two real-world examples of these projects are explored: Arcosanti, AZ and Masdar City, Abu Dhabi, UAE. Key aspects of the arcology that could be applied to an existing urban fabric are identified, such as urban design fostering social interaction, reduction of automobile dependency, and a development pattern that combats sprawl. Through interviews with local representatives, a holistic approach to applying arcology concepts to the Phoenix Metro Area is devised.
ContributorsSpencer, Sarah Anne (Author) / Manuel-Navarrete, David (Thesis director) / Salon, Deborah (Committee member) / Barrett, The Honors College (Contributor) / School of Geographical Sciences and Urban Planning (Contributor) / School of Sustainability (Contributor)
Created2015-05
Description
Prehistoric farmers in the semi-arid American Southwest were challenged by marked spatial and temporal variation in, and overall low levels of, precipitation with which to grow their crops. One strategy they employed was to modify their landscape with rock alignments in order to concentrate surface water flow on their fields. A second challenge that has been less focused on by archaeologists is the need to maintain soil fertility by replenishing nutrients removed from the soil by agricultural crops. Numerous studies have shown that rock alignments can result in long-lasting impacts on soil properties and fertility. However, the direction and magnitude of change is highly variable. While previous work has emphasized the importance of overland flow in replenishing soil nutrient pools, none have investigated the influence of eolian deposition as a contributor of mineral-derived nutrients. This thesis explores the effects of the construction of rock alignments, agricultural harvest, and eolian deposition on soil properties and fertility on Perry Mesa within the Agua Fria National Monument. This site experienced dramatic population increase in the late 1200s and marked depopulation in the early 1400s. Since that time, although agriculture ceased, the rock alignments have remains, continuing to influence runoff and sediment deposition. In the summer of 2009, I investigated deep soil properties and mineral-derived nutrients on fields near Pueblo La Plata, one of the largest pueblos on Perry Mesa. To examine the effects of rock alignments and agricultural harvest independent of one another, I sampled soils from replicated plots behind alignments paired with nearby plots that are not bordered by an alignment in both areas of high and low prehistoric agricultural intensity. I investigated soil provenance and the influence of deposition on mineral-derived nutrients through analysis of the chemical composition of the soil, bedrock and dust. Agricultural rock alignments were significantly associated with differences in soil texture, but neither rock alignments nor agricultural history were associated with significant differences in mineral-derived nutrients. Instead, eolian deposition may explain why nutrient pools are similar across agricultural history and rock alignment presence. Eolian deposition homogenized the surface soil, reducing the spatial heterogeneity of soils. Dust is important both as a parent material to the soils on Perry Mesa, and also a source of mineral-derived nutrients. This investigation suggests that prehistoric agriculture on Perry Mesa was not likely limited by long term soil fertility, but instead could have been sustained by eolian inputs.
ContributorsNakase, Dana Kozue (Author) / Hall, Sharon (Thesis advisor) / Spielmann, Katherine (Committee member) / Hartshorn, Anthony (Committee member) / Arizona State University (Publisher)
Created2012
Description
This paper explores the relationship between wildfire management and the consideration of ecological and environmental concerns in Arizona. To get a proper perspective on the current state of wildfire management in Arizona, information on two wildfire management programs, the Four Forests Restoration Initiative and FireScape, was researched and analyzed, as well as contemporary fire policy, a history of wildfire in Arizona, and two recent fires in Sedona, AZ. The two fires in Sedona, the Brins Fire of 2006 and the Slide Fire of 2014, act as a focal point for this ecological management transition, as even within an 8-year period, we can see the different ways the two fires were managed and the transition to a greater ecological importance in management strategies. These all came together to give a full spectrum for the factors that have led to more ecologically-prominent wildfire management strategies in Arizona.
ContributorsGeorge-Sills, Dylan (Author) / Pyne, Stephen (Thesis director) / Hirt, Paul (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Sustainability (Contributor)
Created2015-05
Description
Currently, approximately 40% of the world’s electricity is generated from coal and coal power plants are one of the major sources of greenhouse gases accounting for a third of all CO2 emissions. The Integrated Gasification Combined Cycle (IGCC) has been shown to provide an increase in plant efficiency compared to traditional coal-based power generation processes resulting in a reduction of greenhouse gas emissions. The goal of this project was to analyze the performance of a new SNDC ceramic-carbonate dual-phase membrane for CO2 separation. The chemical formula for the SNDC-carbonate membrane was Sm0.075Nd0.075Ce0.85O1.925. This project also focused on the use of this membrane for pre-combustion CO2 capture coupled with a water gas shift (WGS) reaction for a 1000 MW power plant. The addition of this membrane to the traditional IGCC process provides a purer H2 stream for combustion in the gas turbine and results in lower operating costs and increased efficiencies for the plant. At 900 °C the CO2 flux and permeance of the SNDC-carbonate membrane were 0.65 mL/cm2•min and 1.0×10-7 mol/m2•s•Pa, respectively. Detailed in this report are the following: background regarding CO2 separation membranes and IGCC power plants, SNDC tubular membrane preparation and characterization, IGCC with membrane reactor plant design, process heat and mass balance, and plant cost estimations.
ContributorsDunteman, Nicholas Powell (Author) / Lin, Jerry (Thesis director) / Dong, Xueliang (Committee member) / Barrett, The Honors College (Contributor) / Chemical Engineering Program (Contributor) / School of Sustainability (Contributor)
Created2014-05
Description
It is well known that deficiencies in key chemical elements (such as phosphorus, P) can reduce animal growth; however, recent empirical data have shown that high levels of dietary nutrients can also reduce animal growth. In ecological stoichiometry, this phenomenon is known as the "stoichiometric knife edge," but its underlying mechanisms are not well-known. Previous work has suggested that the crustacean zooplankter Daphnia reduces its feeding rates on phosphorus-rich food, causing low growth due to insufficient C (energy) intake. To test for this mechanism, feeding rates of Daphnia magna on algae (Scenedesmus acutus) differing in C:P ratio (P content) were determined. Overall, there was a significant difference among all treatments for feeding rate (p < 0.05) with generally higher feeding rates on P-rich algae. These data indicate that both high and low food C:P ratio do affect Daphnia feeding rate but are in contradiction with previous work that showed that P-rich food led to strong reductions in feeding rate. Additional experiments are needed to gain further insights.
ContributorsSchimpp, Sarah Ann (Author) / Elser, James (Thesis director) / Neuer, Susanne (Committee member) / Peace, Angela (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Sustainability (Contributor)
Created2014-05
Description
There are three known materials that readily undergo fission, allowing their use as a base for nuclear fuel: uranium-235, a naturally-occurring but uncommon isotope; plutonium, created from irradiated natural uranium; and uranium-233, produced from thorium. Of the three, uranium-235 and plutonium feature heavily in the modern nuclear industry, while uranium-233 and the thorium fuel cycle have failed to have significant presence in the field. Historically, nuclear energy development in the United States, and thorium development in particular, has been tied to the predominant societal outlook on the field, and thorium was only pursued seriously as an option during a period when nuclear energy was heavily favored, and resources seemed scarce. Recently, thorium-based energy has been experiencing a revival in interest in response to pollution concerns regarding fossil fuels. While public opinion is still wary of uranium, thorium-based designs could reduce reliance on fossil fuels while avoiding traditional drawbacks of nuclear energy. The thorium fuel cycle is more protected against proliferation, but is also much more expensive than the uranium-plutonium cycle in a typical reactor setup. Liquid-fueled molten salt reactor designs, however, bypass the prohibitive expense of U-233 refabrication by avoiding the stage entirely, keeping the chain reaction running with nothing but thorium input required. MSRs can use any fissile material as fuel, and are relatively safe to operate, due to passive features inherent to the design.
ContributorsGalbiati, Joseph Nicco (Author) / Martin, Thomas (Thesis director) / Foy, Joseph (Committee member) / Barrett, The Honors College (Contributor) / School of Sustainability (Contributor)
Created2014-05
Description
Water is the main driver of net primary productivity (NPP) in arid ecosystems, followed by nitrogen and phosphorous. Precipitation is the primary factor in determining water availability to plants, but other factors such as surface rocks could also have an impact. Surface rocks may positively affect water availability by preventing evaporation from soil, but at higher densities, surface rocks may also have a negative impact on water availability by limiting water infiltration or light availability. However, the direct relationship between rock cover and aboveground net primary productivity (ANPP), a proxy for NPP, is not well understood. In this research we explore the relationship between rock cover, ANPP, and soil nutrient availability. We conducted a rock cover survey on long-term fertilized plots at fifteen sites in the Sonoran Desert and used 4 years of data from annual plant biomass surveys to determine the relationship between peak plant biomass and surface rock cover. We performed factorial ANCOVA to assess the relationship among annual plant biomass, surface rocks, precipitation, and fertilization treatment. Overall we found that precipitation, nutrients, and rock cover influence growth of Sonoran Desert annual plants. Rock cover had an overall negative relationship with annual plant biomass, but did not show a consistent pattern of significance over four years of study and with varying average winter precipitation.
ContributorsShaw, Julea Anne (Author) / Hall, Sharon (Thesis director) / Sala, Osvaldo (Committee member) / Cook, Elizabeth (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Membrane-based technology for gas separations is currently at an emerging stage of advancement and adoption for environmental and industrial applications due to its substantial advantages like lower energy and operating costs over the conventional gas separation technologies. Unfortunately, the available polymeric (or organic) membranes suffer a trade-off between permeance and selectivity. Mixed matrix membranes (MMMs) containing two-dimensional (2D) metal-organic frameworks (MOFs) as fillers are a highly sought approach to redress this trade-off given their enhanced gas permeabilities and selectivities compared to the pure polymeric membrane. These MMMs are increasingly gaining attention by researchers due to their unique properties and wide small- and large-scale gas separation applications. However, straightforward and scalable methods for the synthesis of MOFs nanosheets have thus far been persistently elusive. This study reports the single-phase preparation, and characterization of MMMs with 2D MOFs nanosheets as fillers. The prepared MOF and the polymer matrix form the ‘dense’ MMMs which exhibit increased gas diffusion resistance, and thus improved separation abilities. The single-phase approach was more successful than the bi-phase at synthesizing the MOFs. The influence of sonication power and time on the characteristics and performance of the membranes are examined and discussed. Increasing the sonication power from 50% to 100% reduces the pore size. Additionally, the ultimate effect on the selectivity and permeance of the MMMs with different single gases is reported. Analysis of results with various gas mixers indicates further performance improvements in these MMMs could be achieved by increasing sonication time and tuning suitable membrane thicknesses. Reported results reveal that MMMs are excellent candidates for next-generation gas mixture separations, with potential applications in CO2 capture and storage, hydrogen recovery, alkene recovery from alkanes, and natural gas purification.
ContributorsNkuutu, John (Author) / Mu, Bin (Thesis director) / Shan, Bohan (Committee member) / Chemical Engineering Program (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Drilling in Section 1002 has been an ongoing debate since the region was designated as a potential area for drilling projects, pending congressional approval in 1980. In 2017, the area was officially opened up for oil and gas development through its passage in the GOP Tax Cuts and Jobs Act of 2017. This act requires 2 lease sales of 400,000 acres, with an allowed 2,000 acre physical footprint (not including pipelines, ice roads, or gravel mines). Using Social-Life Cycle Assessment methodology to assess the process of oil extraction in Section 1002, significant benefits and drawbacks of drilling in this region, with economic, cultural, and social impacts ranging from the local level to the state level to the national level were identified.
Stakeholders impacted by oil development in the Section 1002 region include the Kaktovik community who lives within the Program Area, the Gwich’in people who live south of ANWR, the corporations who will be leasing the land, as well as the employees who will be working on the projects. These stakeholders share similar values and interests, however, when it comes down to the attainment of these values, there are significant differences in opinion. This debate comes down specifically to the desire to ensure stability for one’s family and community, as this means 2 different things to the majority stakeholders on this issue: The Inupiaq and the Gwich’in. The Inupiaq ,who live in Kaktovik specifically ,are particularly keen on the idea of drilling in the Section 1002 region, because the revenues and opportunities that come with the oil and gas development provide access to better standards of living and a more westernized way of life. The Gwich’in, however, value their relationship to the land and the caribou that are at risk of significant change. These 2 groups are critical to the debate, but the state and federal governments have the final say, and a financial incentive to move forward with the lease sales.
Utilizing the S-LCA framework, life cycle impacts of drilling on society are found using indicators that are identified and assessed using both qualitative and quantitative means. Although some conclusions are uncertain due to the forward-looking nature of this S-LCA, the Increasing/Decreasing trends can be identified and confidently attributed to the specific indicators.
Significant Results:
Significant issues this study has highlighted include the resulting impacts, both positive and negative, on the communities affected by oil and gas development in Section 1002. Significant stakeholders include the Kaktovik community, the Gwich’in people, the oil and gas workers in the state of Alaska, and the oil and gas companies themselves. The local residents are the most affected by the impacts of development, with significant issues pertaining to potential for significant lifestyle change, the increased risk of impact on subsistence species, the risks associated with pollution, and the effect on the economy through revenues and job availability.
Stakeholders impacted by oil development in the Section 1002 region include the Kaktovik community who lives within the Program Area, the Gwich’in people who live south of ANWR, the corporations who will be leasing the land, as well as the employees who will be working on the projects. These stakeholders share similar values and interests, however, when it comes down to the attainment of these values, there are significant differences in opinion. This debate comes down specifically to the desire to ensure stability for one’s family and community, as this means 2 different things to the majority stakeholders on this issue: The Inupiaq and the Gwich’in. The Inupiaq ,who live in Kaktovik specifically ,are particularly keen on the idea of drilling in the Section 1002 region, because the revenues and opportunities that come with the oil and gas development provide access to better standards of living and a more westernized way of life. The Gwich’in, however, value their relationship to the land and the caribou that are at risk of significant change. These 2 groups are critical to the debate, but the state and federal governments have the final say, and a financial incentive to move forward with the lease sales.
Utilizing the S-LCA framework, life cycle impacts of drilling on society are found using indicators that are identified and assessed using both qualitative and quantitative means. Although some conclusions are uncertain due to the forward-looking nature of this S-LCA, the Increasing/Decreasing trends can be identified and confidently attributed to the specific indicators.
Significant Results:
Significant issues this study has highlighted include the resulting impacts, both positive and negative, on the communities affected by oil and gas development in Section 1002. Significant stakeholders include the Kaktovik community, the Gwich’in people, the oil and gas workers in the state of Alaska, and the oil and gas companies themselves. The local residents are the most affected by the impacts of development, with significant issues pertaining to potential for significant lifestyle change, the increased risk of impact on subsistence species, the risks associated with pollution, and the effect on the economy through revenues and job availability.
ContributorsJunglas, Hillary L (Author) / Pasqualetti, Martin (Thesis director) / Breetz, Hanna (Committee member) / Department of Supply Chain Management (Contributor) / School of Sustainability (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Human activity produces ambient noise that potentially alters species’ abilities to communicate with each other—among other impacts. Given that birds are known to be sensitive to structural changes in habitat and highly communicative through sound, it is beneficial to understand how changing acoustic ecologies and ambient noise impact birds’ ability to communicate in their respective environments. In this study, mockingbird calls from an urban, desert, and intermediate study site were recorded and analyzed for differences in acoustic properties. Acoustic properties such as frequency and amplitude differed significantly across sites as it was determined that mockingbirds in urban areas increase both the peak frequency and amplitude of their calls in order to communicate. This study identifies what these changes in acoustic properties mean in relation to the survival and conservation of birds and concludes with recommendations for novel research.
ContributorsReynolds, Bailey Susana (Author) / Pearson, David (Thesis director) / Walters, Molina (Committee member) / School of Sustainability (Contributor) / School of Life Sciences (Contributor) / Dean, W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05