Spelling suggestions: "subject:"environmental"" "subject:"environmental's""
561 |
Characterization and Implications of Surface Hydrophobicity in Nanoparticle Fate and TransportXiao, Yao January 2012 (has links)
<p>Surface chemistry plays an essential role in determining the reactivity, bioaccessibility, bioavailability and toxicity of nanoparticles (NPs) in the environment. Processes such as aggregation, deposition and biouptake are controlled in part by the attachment efficiency, α, between particles and the surfaces they encounter. One premise of this research is that surface hydrophobicity is a pivotal property of NP surfaces that can affect the behavior of NPs in aquatic environment and potentially decide the fate and transport of NPs. However, there are multiple challenges in the characterization of hydrophobicity for NPs. Methods developed for macroscopic surfaces or organic compounds may not be readily applied or interpreted for the case of nano-scale surfaces. This dissertation addresses theoretical basis for applying methods to determining hydrophobicity of NPs. The use of an octanol-water partitioning method analogous to that used for organic compounds was evaluated on the basis of trends anticipated by thermodynamics, and by experimental observations. This work shows that partitioning of NPs in two phases systems, such as water and octanol, is not uniquely determined by hydrophobicity, but also influenced by surface charge and particle size. The water-oil interface rather than the bulk phases becomes the thermodynamically favored location for NP accumulation once NPs are larger than 1-10 nm and/or the surface is amphiphilic. </p><p>Nonetheless, the relative hydrophobicity of selected NPs, as characterized by adsorption of molecular probes (i.e. organic dye and naphthalene), was consistent with the macroscopic contact angle measurements and octanol-water distribution coefficients. The in-situ adsorption of these molecular probes offers the most solid grounds for measurement of hydrophobicity. Other measure of hydrophobicity or hydrophilicity such as water-affinity based methods that measure water vapor adsorption to nanomaterial powders, or immersion microcalorimetry and thermogravimetric analysis, yielded similar results to the molecular probes. However, possible physical or chemical transformations to NP surfaces during characterization by these other methods limited the use of results to infer hydrophobicity based on a rigorous thermodynamic model.</p><p>Column experiments suggested that the attachment efficiency of NPs to biofilm was generally greater for more hydrophobic NPs, though polymeric coatings might stabilize NPs against the attachment. The affinity of NPs for a variety of bacterial surfaces (i.e. different species, planktonic or biofilm, with or without extracellular polymeric substances (EPS)) of different hydrophobicities, which correlated with the quantity of proteins in EPS, was also investigated. It was found that the attachment of hydrophobic NPs increased with the hydrophobicity of bacterial surfaces, but not for hydrophilic NPs. Environmental conditions such as divalent ions and pH influenced the affinity of nanoparticle for bacterial surface by changing the bacterial surface hydrophobicity and electric double layer interaction, respectively.</p> / Dissertation
|
562 |
The Value of Knowing: Public Lands Monitoring by Non-Agency GroupsOlsen, Aaron Richard 27 June 2013 (has links)
It is generally recognized that in order to make informed federal land management decisions, such decisions need to be based on information gathered from monitoring of those lands. While some monitoring is being conducted by federal land management agencies, it is happening too infrequently and is often inadequate for properly informing land management decisions. In an attempt to fill this gap non-agency groups have begun monitoring federal public lands themselves. It appears that through recent congressional authorizations, policy reforms, and agency initiatives monitoring by non-agency groups is being supported at every government level. While theoretically this transfer of responsibility from the federal agencies to non-agency groups looks good on paper in reality there are considerable barriers. This has many groups gathering data that ends up never being used in the decision making process. Despite this barrier, however, non-agency groups continue to monitor while the topic itself garners increased attention. As it stands, our understanding of how non-agency monitoring can affect land management decision making is seen as fairly black and white; data from monitoring is either used by the agency to make decisions or it is not. This study suggests that such a view of monitoring by non-agency groups is too narrow. The values associated with monitoring on federal public lands can be seen as having an internal or external benefit. Internal benefits, such as engaging youth or leveraging funding, are those that primarily only affect the monitoring group. External benefits, such as filling in gaps of agency monitoring or informing adaptive management within the agency, are those that may lead to either directly or indirectly influencing land management decision making. Ultimately, directly influencing federal land management decision making is difficult and may be out of reach for many non-agency groups. However those benefits that affect the group itself may be easier to achieve and could act as a starting point for groups wanting to start monitoring. Over time external benefits can be realized such as building relationships with agency staff, building public support, or informing NEPA reports that can lead to indirectly influencing federal land management decision making. Furthermore, there are differences between how single-interest groups and multi-interest groups value monitoring. Combined, these insights can assist groups in focusing their monitoring goals in order to increase the longevity and success of monitoring activity.
|
563 |
Paying to Play: Supply Management in Montana's Dairy IndustryGinsburg, Laura 27 June 2013 (has links)
Montanas dairy industry is unique among US states because of its supply management program, which allocates quota to limit how much fluid milk can be produced and sold within the state. The amount of quota is set and price varies with market conditions; therefore, quota adds to a farms production costs. This paper presents findings from in-depth interviews with 17 dairy farmers to learn how quota has affected on-farm decision-making and how they perceive the impacts of quota on the statewide industry. Farmers tend to be spilt between those who think it affected their on-farm decisions and those who felt that other factors had greater impact. Farmers perceive effects such as supply stagnation, increased expenses, industry protection from other states, and possibly stabilizing the price of milk. The qualitative approach used here differs from past research in other nations, which typically focused on the financial implications of supply management.
|
564 |
Putting Scientific Information into the Service of Environmental Justice for Residents Facing Groundwater ContaminationSorovacu, Yvonne Emily 27 June 2013 (has links)
Opportunity, Montana is a small town within the 300 square mile Anaconda Smelter Superfund site in Western Montana. Waste from 100 years of ore processing has impacted the area. Arsenic exceeds Montana drinking water standards within the aquifer system feeding residential wells of Opportunity, causing resident concern about current and future safety of drinking water. The project described in this paper engages with this context from an environmental justice (EJ) perspective that views meaningful participation of affected communities as integral for sound and democratic decisions about environmental risks. Because Opportunity residents are left out of important decision making processes regarding local groundwater remediation, they experience procedural injustice, an aspect of EJ calling for meaningful participation. The project aims to reduce barriers to meaningful participation by improving residents abilities to access and use scientific information and explanations for local groundwater contamination, a need identified through previous literature and resident comments. Science education, risk communication, and science communication literature, along with Superfund site studies, provided general insights about relevant groundwater information and concepts as well as effective ways of communicating this technical information to residents. I used a three-step process to further specify and address resident needs and concerns regarding groundwater contamination. First, I conducted focus group interviews with ten Opportunity residents in the spring of 2012. Qualitative analysis of these interviews identified needs regarding site data and relevant groundwater concepts. Secondly, this analysis, along with literature, informed creation of a public presentation about groundwater contamination in the Opportunity area, offered to receive feedback from residents for development of an informational booklet. I received an unsatisfactory amount of feedback from this step. Thirdly, I adapted presentation material with the received feedback and a more rigorous application of insights from literature into a 24-page informational booklet, containing images designed for the project. With support of other nonprofits conducting outreach to Superfund communities, I intend to publish and distribute the booklet as a resource for Opportunity residents seeking better and more useful information to address concerns with drinking water.
|
565 |
We Humans: Nature, Culture, and Identity in the Anthropocene AgeSpivey, Hudson Douglas 28 June 2013 (has links)
In 2000, atmospheric chemist Paul Crutzen published a paper in the journal Nature in which he argued that human activity had become the primary force shaping the geology, hydrology, atmosphere, and climate of planet Earth. Crutzen proposed the inauguration of a new geological epoch termed the Anthropocene, which denoted the human domination of the biosphere. Since then, a number of geologists and Earth systems scientists have joined Crutzen in calling for a ratification of this new name. Popular science writers like Emma Marris and Mark Lynas have also celebrated the dawn of The Age of Humans, claiming that it legitimizes a much deeper technological intervention by humans in the life systems of the planet.
This thesis analyzes the historical narratives deployed within the scientific papers and popular books on the Anthropocene to justify this more intensified technological intervention. Each of these papers presents a capsule version of human history, which often depicts the species Homo sapiens as progressing on a linear, universal path to our current form of global dominance. The narrative proceeds from hunter-gatherers wielding fire, to sedentary agrarian city-states, to modern, urban technological societies engaged in global-scale management and ecological degradation.
This thesis offers a critique of the notion that all human beings are represented in the cumulative impacts that have been collectively termed The Anthropocene. Utilizing the insights gained from post-colonial and Indigenous studies, as well as environmental history and cultural ecology, I attempt to examine fundamental differences in worldview and lifeways between what Raymond Dasmann called biosphere peoples and small-scale, traditional societies, or ecosystem peoples. By tracing the movement of biospheric dependence and industrial growth out of the centers of European and Euro-American power, I suggest that the Anthropocene originated out of deliberate colonial attempts to restructure traditional, land-based societiesand the lands they occupiedto fit Western-style developmental models. As Earth Systems scientists, social scientists, conservationists, activists, and policy makers attempt to devise ways of adapting to or mitigating planetary-scale environmental challenges, I argue that it is important to properly define the problem in order to develop adequate, properly-scaled solutions.
|
566 |
A Chicken in Every Lot: The 2007 Chicken Ordinance in Missoula, MontanaSheridan, Kate Margaret 28 June 2013 (has links)
In 2007, the City Council of Missoula, Montana passed an ordinance allowing six chickens per urban lot. Missoula followed the lead of many other cities seeking to expand urban agriculture and food security opportunities through microlivestock. This paper gives context to the implementation of a specific ordinance, investigates the benefits and challenges experienced by twenty households in Missoula, and connects it back to the food system as a whole.
|
567 |
Responses to climate change in National Park Service Wilderness: What is happening in the field?Nelson, Katherine E 28 June 2013 (has links)
As scholars debate whether climate change warrants more or less active management in wilderness, this baseline study identifies what is happening on the ground. This study focuses attention on National Park Service units that administer designated wilderness. Representatives who had been identified by the superintendents from each of these units responded to an online survey (with a 94% response rate). Respondents reported on their concerns, monitoring, and management projects driven by climate change happening in their wilderness. Respondents also discussed whether and how these activities affected wilderness character. This is the first study to characterize the response to climate change in wilderness at a national scale. A majority of park units are conducting stewardship activities in wilderness to address and track the effects of climate change. Invasive species and fire are receiving much attention in the process. As park units respond to climate change in wilderness they cite perceived improvements to the natural quality of wilderness character. They also indicate that these activities harm the natural quality of wilderness character along with a suite of other qualities that have been left out of the academic discussion regarding appropriate management responses. The findings thus provide basic information to NPS administrators about what is happening in the field. They also give those discussing appropriate stewardship responses the fabric within which to sew their arguments. Finally, this study explores lessons learned from climate change adaptation in wilderness that may be applicable to adaptation activities happening elsewhere.
|
568 |
EFFECT OF COVER ON SMALL MAMMAL ABUNDANCE AND MOVEMENT THROUGH WILDLIFE UNDERPASSESConnolly-Newman, Hayley R 28 June 2013 (has links)
Crossing structures enable wildlife to safely cross highways by physically separating wildlife and vehicles. Most wildlife underpasses and overpasses are designed to accommodate a wide variety of species. Their suitability for individual species, however, varies by location (surrounding habitat), structure type (e.g. underpass or overpass), and dimensions (height, width, length). For some taxa, the habitat immediately adjacent to and inside an underpass or on top of an overpass is critical. For instance, small mammals, reptiles, amphibians and many invertebrates may avoid open areas because they require cover (e.g., live vegetation, tree stumps, branches, or rocks) to reduce predation risk and because of the microhabitat it provides (e.g., temperature, moisture). I investigated the effect of cover on the abundance and movements of small mammals in ten large mammal underpasses (approximately 7 m wide, 4 m high) along U.S. Hwy 93 North on the Flathead Indian Reservation, Montana. Track tubes recorded abundance of small mammals in and around 10 structures (5 control/ 5 treatment) in 2011 and 2012. I placed cover (dead tree limbs) inside half (five) of the underpasses in winter 2012 (treatment), while the remaining five underpasses served as control with no cover added. Capture-mark-recapture using live traps was conducted in the fall of 2012 to record abundance and movement of small mammals in and around the underpasses. There was no statistically significant effect of cover on small mammal abundance detected by track tubes or live traps. . There was a statistically significant effect of cover on movement between the right of way and crossing structure for small mammals detected by live traps. By placing cover inside wildlife underpasses, wildlife managers can increase crossing structure use by small mammals at minimal cost.
|
569 |
PLACE-BASED EDUCATION, FUNDS OF KNOWLEDGE AND STUDENTS UNDERSTANDING OF WATER SYSTEMSRorick, Meghan 28 June 2013 (has links)
In light of the impacts of climate and land use change on water quality and distribution worldwide, it is important that citizens make informed decisions regarding human land and water use. Many, however, lack the scientific knowledge necessary to understand these issues, indicating that todays school system is not adequately preparing many students to become active, environmentally literate citizens.
Place-based education (PBE) and sensitivity to students funds of knowledge (FOK) are two recent approaches that may help teachers and school officials develop science curricula and instructional practices that better support students in developing scientific understanding. This thesis examines the relationship between western Montana and Tucson, Arizona 6th grade students PBE experiences, their water-related FOK, and their understanding of water systems.
As part of the larger Water Reasoning Tools project, students took a water knowledge pre-test before lessons in class. They also took a survey that asked about their past PBE and water-related FOK experiences. For this study, the students pretests were analyzed using the water learning progression assessment framework. Their surveys were also analyzed, and students were given scores that reflect their PBE and FOK experiences. The pretest and survey scores were then statistically compared to see if there were correlations between the variables (water knowledge, PBE, and FOK).
Results showed that the 6th grade students in these states demonstrated informal reasoning about water systems, and that they have had relatively few PBE and FOK experiences. Results also showed a correlation between students scores on some sections of the pretest and their FOK experiences. There was no correlation, however, between test scores and PBE. This could be due to students few past experiences with PBE and FOK learning. In addition, the small amount of variance among all three variables made it difficult to find significant correlations.
At a time when scientists are speaking directly to the public, it is important that our schools support students in becoming citizens capable of using model-based, scientific reasoning to make decisions about environmental issues. With further development, PBE and sensitivity to students FOK may be two approaches with promise for designing science curricula to help students learn science with understanding.
|
570 |
Prioritizing The Upper Clark Fork River Tributaries for Instream Flow RestorationBerg, Catherine B. 28 June 2013 (has links)
Off stream uses of water in the west have left many rivers and streams depleted, including the Upper Clark Fork River and its tributaries. As drought conditions persist or worsen, this issue will become more critical. Public-private partnerships, like the Upper Clark Fork Steering Committee, have formed to monitor the flow of our rivers. In order to assist the Steering Committee and river advocacy groups working within the Upper Clark Fork River Basin, this paper provides a comprehensive review of the studies on existing flows and target flows in the upper river, synthesizes past priorities for stream restoration, and provides a case study on how to find flows to rewater a key tributary. With this information, government agencies, nonprofit organizations, and others will have a more complete understanding of how to prioritize tributaries for rewatering and restoration with their limited budgets and personnel. This will also aid in the development of the report due to the legislature every five years by the Upper Clark Fork River Basin Steering Committee that is intended to review the basin closure and make recommendations to the legislature regarding necessary changes.
|
Page generated in 0.0781 seconds