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Landfill site trees: Potential source or sink of greenhouse gases?
Tree stems can transport greenhouse gases (GHGs) produced belowground to the atmosphere. Previous studies in natural wetland and upland ecosystems have quantified tree stem fluxes of methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O). However, tree stem GHG fluxes have not previously been measured in the context of managed environments. The work presented in this thesis aimed to quantify GHG fluxes from tree stems on closed landfill sites.
To investigate the potential for trees growing on closed landfill sites to act as conduits for GHGs produced belowground to the atmosphere, GHG fluxes were measured from tree stem and soil surfaces. In situ measurements from a closed landfill site in the UK were examined for spatial and temporal patterns and evaluated against data from a comparable non-landfill area. Measurements were also conducted from landfill sites in the UK with varying management practices and different tree species present. The resulting flux values were scaled up to estimate the magnitude of tree stem GHG fluxes from closed landfills at a national level.
The findings presented here show evidence of tree mediated GHG transport on closed landfill sites and temporal variations in fluxes from tree stems were also observed, with generally higher fluxes in the summer months. Stem CH4 fluxes varied between trees growing on landfill sites with different management practices. Additionally, stem N2O fluxes displayed spatial patterns, with decreasing emissions at increased height from the forest floor, indicating an underground source. Evidence suggested that GHG fluxes from closed landfills are influenced by factors including the quantity of GHG produced in the waste (linked to the age of the site), the susceptibility of the area to waterlogging and landfill management techniques put in place upon closure (for example, clay caps, cover soils and gas extraction). Upscaled CH4 and N2O flux values from tree stems on closed landfill sites corresponded to less than 1% of the total CH4 and N2O emissions reported from UK landfills in 2020.
Overall, results indicated that measuring soil fluxes alone from forested landfill sites would result in an underestimation of the total surface fluxes. However, the emission rates from tree stems on closed landfills observed in this thesis do not exceed those in natural ecosystems. Therefore, with careful planning and management, the recommendation is that trees can be planted on closed landfill sites in the UK without emitting atypical levels of GHGs. However, including gas fluxes from tree stems on closed landfills would increase the accuracy of GHG budgets at national and global levels
Beam scanning by liquid-crystal biasing in a modified SIW structure
A fixed-frequency beam-scanning 1D antenna based on Liquid Crystals (LCs) is designed for application in 2D scanning with lateral alignment. The 2D array environment imposes full decoupling of adjacent 1D antennas, which often conflicts with the LC requirement of DC biasing: the proposed design accommodates both. The LC medium is placed inside a Substrate Integrated Waveguide (SIW) modified to work as a Groove Gap Waveguide, with radiating slots etched on the upper broad wall, that radiates as a Leaky-Wave Antenna (LWA). This allows effective application of the DC bias voltage needed for tuning the LCs. At the same time, the RF field remains laterally confined, enabling the possibility to lay several antennas in parallel and achieve 2D beam scanning. The design is validated by simulation employing the actual properties of a commercial LC medium
YIELD TO PEDESTRIANS? EXAMINING INFRASTRUCTURE AND DEFENSIVE-MINDED METHODOLOGIES IN SECURING PEDESTRIAN-RICH ENVIRONMENTS
Urban municipalities feature pedestrian-rich environments with limited mitigation measures to prevent vehicle-caused pedestrian fatalities. Limited pedestrian protections represent an attractive target for nefarious actors to commit vehicle ramming attacks (VRA). There are defensive-minded methodologies that afford greater mitigation against deadly vehicle-versus-pedestrian collisions and VRAs in urban pedestrian-rich environments. This thesis examines the vulnerability of pedestrian-rich environments to vehicle-caused pedestrian fatalities and provide recommendations for stakeholders to better secure the environments. It also examines both the target hardening and protective security methodologies using a theoretical analysis model. By analyzing these defensive-minded methodologies, this thesis explores a homogenous framework for securing urban pedestrian-rich environments: the target hardening/protective security spectrum (THPSS). This thesis concludes with recommendations for urban municipalities to implement to better protect their respective pedestrian-rich environments from deadly vehicle-versus-pedestrian collisions and VRAs. This thesis provides recommendations to better secure outdoor dining establishments, street fairs, road races, and urban public parks from vehicle-caused fatalities.Civilian, New York City Police DepartmentApproved for public release. Distribution is unlimited
Complicated objects: artifacts from the Yuanming Yuan in Victorian Britain
The 1860 spoliation of the Summer Palace at the close of the Second Opium War by British and French troops was a watershed event within the development of Britain as an imperialist nation, which guaranteed a market for opium produced in its colony India and demonstrated the power of its armed forces. The distribution of the spoils to officers and diplomatic corps by campaign leaders in Beijing was also a sign of the British Army’s rising power as an instrument of the imperialist state. These conditions would suggest that objects looted from the site would be integrated into an imperialist aesthetic that reflected and promoted the material benefits of military engagement overseas and foregrounded the circumstances of their removal to Britain for campaign members and the British public.
This study mines sources dating to the two decades following the war – including British newspapers, auction house records, exhibition catalogs and works of art – to test this hypothesis. Findings show that initial movements of looted objects through the military and diplomatic corps did reinforce notions of imperialist power by enabling campaign members to profit from the spoliation through sales of looted objects and trophy displays. However, material from the Summer Palace arrived at a moment when British manufacturers and cultural leaders were engaged in a national effort to improve the quality of British goods to compete in the international marketplace and looted art was quickly interpolated in this national conversation. Ironically, the same “free trade” imperatives that motivated the invasion energized a new design movement that embraced Chinese ornament.
As a consequence, political interpretations of the material outside of military collections were quickly joined by a strong response to Chinese ornament from cultural institutions and design leaders. Art from the Summer Palace held a prominent place at industrial art exhibitions of the postwar period and inspired new designs in a number of mediums. While the availability of Chinese imperial art was the consequence of a military invasion and therefore a product of imperialist expansion, evidence presented here shows that the design response to looted objects was not circumscribed by this political reality. Chinese ornament on imperial wares was ultimately celebrated for its formal qualities and acknowledged links to the Summer Palace were an indicator of good design, not a celebration of victory over a failed Chinese state. Therefore, the looting of the Summer Palace was ultimately an essential factor in the development of modern design, the essence of which is a break with Classical ornament
L’utilisation de dictionnaires de langues algonquiennes comme sources ethnographiques : étude de cas sur la culture légale et les pratiques juridiques illinoises au tournant du XVIIIe siècle
Abstract: Miami-Illinois is an Algonquian language that, in the 18th century, was to be heard to the south of the Great Lakes. In the 19th century, forced removals and the reservation system led to cultural and linguistic fragmentation amongst Miami-Illinois speakers. Against this current, language revitalization efforts began in the mid-1990s and, due to these, Miami-Illinois is again a spoken language. A wealth of documentation is now available through the Indigenous Languages Digital Archive. This thesis draws on this resource, in conjunction with other archival and published sources, to elicit an understanding of the legal culture of the people called Illinois by the French, particularly that of the Kaskaskias (kaahkaahkiaki), as it was in the early 18th century. Building on linguistic and historical sources, this work explores their jurispractice in relation to cases that have been preserved in the archives of the French overseas empire. Three points are addressed, namely: (i) how the Illinois (and Myaamia) thought about justice in the early 18th century; (ii) how the Miami-Illinois–and–French dictionaries can provide a new depth of understanding about this; and (iii) the limits to our ability to elicit abstract concepts from a fragmentary historical record.Au XVIIIe siècle, le miami-illinois (langue de la famille algonquienne) était traditionnellement parlée au sud des Grands Lacs. Le XIXe siècle a vu une fragmentation culturelle et linguistique parmi les locuteurs du miami-illinois. Des efforts de revitalisation de la langue ont commencé vers 1995. Grâce à ce travail minutieux, le miami-illinois est redevenu une langue parlée. Il y a maintenant une grande richesse de matériels linguistiques disponibles grâce à la banque de données Indigenous Languages Digital Archive. Cette thèse a pour but d’explorer la culture juridique des Illinois au début du XVIIIe siècle, avec une attention particulière pour le peuple kaskaskia (kaahkaahkiaki). En étudiant des cas réels préservés dans les archives de la Nouvelle France et en se basant sur des sources linguistiques et historiques, ce texte explore les pratiques juridiques des Illinois. Trois points sont étudiés : (i) la conception de la justice des Illinois (et Myaamia) au début du XVIIIe siècle; (ii) comment les dictionnaires jésuites en miami-illinois et français peuvent améliorer notre connaissance et compréhension de cette période; et (iii) les limites de la recherche dans l’histoire des idées dans les archives historiques incomplètes
Bowing Sand, Dust, and Dunes, Then and Now–A North American Perspective
Dune fields of the present day, the Dust Bowl disaster of the 1930s U.S. Great Plains, and contemporary efforts to forecast, simulate, and understand dust storms have a striking, uniform commonality. What these apparently diverse phenomena have in common is that they all result from blowing sand and dust. This review paper unifies these three disparate but related phenomena. Its over-arching goal is to clearly explain these manifestations of windblown sand and dust. First, for contemporary dune fields, we offer reviews of two technical papers that explain the eolian formation and the continuing development of two major dune fields in southeastern California and northwestern Sonora, Mexico: the Algodones Dunes and the Gran Desierto de Altar. Second, historical, geological, meteorological, and socioeconomic aspects of the 1930s Great Plains Dust Bowl are discussed. Third, and last, we return to the present day to summarize two lengthy reports on dust storms and to review two technical papers that concern their forecasting and simulation. The intent of this review is to acquaint the interested reader with how eolian transport of sand and dust affects the formation of present-day dune fields, human agricultural enterprises, and efforts to better forecast and simulate dust storms. Implications: Blowing sand and dust have drastically affected the geological landscape and continue to shape the formation of dune fields today. Nearly a century ago the U.S. Great Plains suffered through the Dust Bowl, yet another consequence of blowing sand and dust brought on by drought and mismanagement of agricultural lands. Today, this phenomenon adversely affects landscapes, transportation, and human respiratory health. A more complete understanding of this phenomenon could (and has) led to more effective mitigation of dust sources, as well as to a more accurate predictive system by which the public can be forewarned
Cultivating Agrobiodiversity in the U.S.: Barriers and Bridges at Multiple Scales
The diversity of crops grown in the United States (U.S.) is declining, causing agricultural landscapes to become more and more simplified. This trend is concerning for the loss of important plant, insect, and animal species, as well as the pollution and degradation of our environment. Through three separate but related studies, this dissertation addresses the need to increase the diversity of these agricultural landscapes in the U.S., particularly through diversifying the type and number of crops grown. The first study uses multiple, openly accessible datasets related to agricultural land use and policies to document and visualize change over recent decades. Through this, I show that U.S. agriculture has gradually become more specialized in the crops grown, crop production is heavily concentrated in certain areas, and crop diversity is continuing to decline. Meanwhile, federal agricultural policy, while having become more influential over how U.S. agriculture operates, incentivizes this specialization. The second study uses nonlinear statistical modeling to identify and compare social, political, and ecological factors that best predict crop diversity across nine regions in the U.S. Factors of climate, prior land use, and farm inputs best predict diversity across regions, but regions show key differences in how factors are important, indicating that patterns at the regional scale constrain and enable further diversification. Finally, the third study relied on interviews with farmers and key informants in southern Idaho’s Magic Valley – a cluster of eight counties that is known to be agriculturally diverse. Interviews gauge what farmers are currently doing to manage crop diversity (the present) and how they imagine alternative landscapes (the imaginary). We found that farmers in the Magic Valley manage current diversity mainly through cover cropping and diverse crop rotations, but daily struggles and political barriers make experimenting with and imagining alternative landscapes difficult and unlikely to occur. Together, these three studies provide an integrated view of how and why U.S. agriculture landscapes simplify or diversify, as well as the barriers and bridges such pathways of diversification
Conservation, Restoration, and Monitoring Plan for the Lower White River, Utah
In this report we present a conservation, restoration and monitoring plan for the lower White River, a major tributary of the Green River. The plan is intended to help guide conservation, restoration and management of the lower White River over the next several decades and is also developed as an adaptive management plan to facilitate learning. The recommended conservation and restoration actions are intended to maintain and enhance native riparian vegetation and instream habitat for native desert fishes including federally endangered Colorado Pikeminnow (Ptychocheilus lucius), federally endangered Razorback Sucker (Xyrauchen texanus), Speckled Dace (Rhinichthys osculus), Bluehead Sucker (Catostomus discobolus), Flannelmouth Sucker (C. latipinnis), and Roundtail Chub (Gila robusta). ~~Many mammals, amphibians, migratory birds, and raptors that use the riparian zone or migrate through the riverscape are also anticipated to benefit from the plan. The recommended conservation and restoration actions are based on the best available information regarding the current ecological and geomorphic conditions and restoration recovery potential. We prioritized reaches for conservation and restoration actions using expert opinion and field validation, riparian vegetation density and instream and riparian habitat condition and complexity data. We recommend an experimental design for implementation of conservation and restoration actions. Combined with monitoring, the experimental design is aimed at identifying the most successful conservation and restoration actions for maintaining complex instream habitat and a healthy native riparian community
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