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Forest Carbon Storage In The Northeastern United States: Effects Of Harvesting Frequency And Intensity Including Wood Products, Jared Nunery

Graduate College Dissertations and Theses

Temperate forests are an important carbon sink, yet there is debate regarding the net effect of forest management practices on carbon storage. Few studies have investigated the effects of different silvicultural systems, and the relative strength of in-situ forest carbon versus wood products pools remains in question. Our research (1) describes the impact of harvesting frequency and degree of post- harvest structural retention on carbon storage in northern hardwood-conifer forests, and (2) tests the significance of including harvested wood products in carbon accounting at the stand scale. We stratified Forest Inventory and Analysis (FIA) plots to control for environmental, forest …

Nutrient Allocations And Metabolism In Two Collembolans With Contrasting Reproduction And Growth Strategies, Thomas Larsen, Marc Ventura, Christian Damgaard, Erik A. Hobbie, Paul Henning Krogh

Faculty Publications

Physiological mechanisms such as allocation and release of nutrients are keys to understanding an animal's adaptation to a particular habitat. This study investigated how two detrivores with contrasting life‐history traits allocated carbon (C) and nitrogen (N) to growth, reproduction and metabolism. As model organisms we used the collembolans, Proisotoma minuta (Tullberg 1871) and Protaphorura fimata (Gisin 1952).

To estimate allocations of C and N in tissue, we changed the isotopic composition of the animal's yeast diets when they became sexually mature and followed isotope turnover in tissue, growth and reproduction for 28 days. In addition, we measured the composition of …

Continuum Theory Of Carbon Phases, Alexander Umantsev, Zinoviy Akkerman

Chemistry and Physics Faculty Working Papers

We constructed a continuum theory of carbon phases based on the Landau theory of phase transitions. Our theory ties up many seemingly unrelated data on the carbon system. Transformations between graphite, diamond, and liquid-carbon are described by the Landau– Gibbs free-energy which depends on two order parameters: crystallization and structural. The barrier-height and gradient-energy coefficients were calculated from the nucleation data obtained in the studies of diamond/graphite and diamond/liquid-carbon systems. The boundary of the absolute stability of the graphitic phase was interpreted as the spinodal point of the free-energy, which allowed us to calculate the pressure dependence of the barrier-height …

Using Keeling Plots To Trace Δ13C And Δ18O Of Co2 Through Processes Of Heterotrophic Respiration, Diffusion And Soil Water Equilibration In Artificial C3- And C4-Grassland Soils, Jennifer Chelladurai

USF Tampa Graduate Theses and Dissertations

Global carbon cycle dynamics and fluxes of CO₂ between biosphere and atmosphere have been progressed through the use of Keeling Plots. Processes that control and effect the isotopic composition of soil-respired CO₂, soil CO₂, and equilibrated soil carbonate are specifically addressed in this study through the use of Keeling Plots. Replicate grassland soil profiles containing either C3 or C4 homogenized organic matter were constructed and maintained under controlled settings to encourage the production of soil-respired CO₂ and the precipitation of pedogenic carbonate. Soil CO₂ was sampled over five months and analyzed with IRMS. …

Patterning And Characterization Of Carbon Nanotubes Grown In A Microwave Plasma Enhanced Chemical Vapor Deposition Chamber, Mauricio Kossler

Theses and Dissertations

This research studies the growth of carbon nanotubes (CNT) from a nickel catalyst to be used on a field emission device. This thesis can be divided into three sections: the construction of a vacuum chamber for field emission testing, the design and fabrication of a triode structure to enable improved electron emission, and the pretreatment and growth of CNTs. To experimentally test the field emission of CNTs, a vacuum chamber must attain a vacuum of at least 10^-5 torr. Our vacuum chamber designed and built achieved a maximum, final pressure of 10^-8 torr. A triode structure was designed …

Small Mammals In Portions Of Great Basin National Park Susceptible To Groundwater Withdrawal: Diversity And Stable Isotope Perspectives, Bryan T. Hamilton

Theses and Dissertations

To support population growth in Las Vegas, Nevada, large scale increases in groundwater pumping are planned across the state. This pumping could affect riparian areas in Great Basin National Park by lowering groundwater levels, reducing stream flows, and xerifying riparian vegetation. Great Basin National Park (GBNP) is mandated to manage its resources unimpaired for future generations. Loss of biodiversity is unacceptable under this mandate. If groundwater levels are reduced beyond a threshold, aquatic and riparian diversity would be lost, but the effects on small mammal communities are less clear. To provide baseline information and to consider the effects of groundwater …

Tribological Behavior And Film Formation Mechanisms Of Carbon Nanopearls, Chad Nicholas Hunter

Graduate Theses and Dissertations

No abstract provided.

Material Selection Of Z-Fibre In Stitched Composites - Experimental And Analytical Comparison Approach, Kwek Tze Tan, N. Watanabe, M. Sano, M. Takase, Y. Iwahori, H. Hoshi

Mechanical Engineering Faculty Research

Strain energy release rates are measured and compared for laminated composites stitched with different fibre materials – Carbon, Kevlar and Vectran. DCB test and FE simulation are performed to evaluate the interlaminar toughness. It is proven that Vectran provides the toughest interlaminar reinforcement and is most suitable for Zfibre application.

A Baseline Greenhouse Gas Inventory For Oberlin: Stepping Up To The Challenge Of Climate Neutrality, Nathaniel Flaschner Meyer

Honors Papers

The City of Oberlin joined the International Council for Leadership in Environmental Initiatives (ICLEI) in 2007, committing to reduce greenhouse gas emissions through ICLEI's five-milestone process. As the first official step in this process, I conducted greenhouse gas inventories for the years 2001 and 2007 for community-wide and municipal operations emissions. I found that the community emitted 174,400 tons of carbon dioxide equivalent in 2007, more than half of which was associated with the consumption of coal-intensive electricity. This amounts to 20.9 tons CO2e per resident annually. Of the community's overall emissions, the commercial sector, including all Oberlin College properties, …

Carbon Regulation And Its Impact On The Appalachian Basin: Why The Coal-Fired Energy Industry In Appalachia Should Embrace, Prepare For, And Help Shape A Comprehensive Legislative Scheme That Limits Greenhouse Gas Emissions, Mark L. Belleville

Mark L. Belleville

The premise of this article – the coal-fired energy industry in Appalachia should embrace, prepare for, and help shape a comprehensive federal legislative scheme that limits carbon dioxide and other greenhouse gas emissions – may sound counterintuitive. Why would an industry that emits greenhouse gases (GHGs) get on board with a national plan to limit GHG emissions? The reason is threefold. First, some form of regulation limiting emissions is inevitable. Second, in many respects, a comprehensive federal scheme is preferable to the current patchwork that exists. Finally, a comprehensive federal scheme can be tailored to be advantageous (or at least …

Diffusive Growth Of Fullerenes And Carbon Nanotubes, J E. Bunder, James M. Hill

Faculty of Informatics - Papers (Archive)

The video of a growing fullerene within a carbon nanotube, initiated by a tungsten catalyst, provides a dramatic realization of a complex nanoscale process. While there may be many detailed models which can account for this growth, we propose one of the simplest possible models which is consistent with the major observed features of the growth process. In particular, we assume that the fullerene is immersed in a carbon vapor environment, and that the growth occurs as a consequence of the diffusion of the carbon vapor into the fullerene. Moreover, we assume that the classical diffusion equation applies in the …

Zigzag Carbon Nanotubes With Generic Electron-Electron Interactions, James M. Hill, J. E. Bunder

Faculty of Informatics - Papers (Archive)

A Hamiltonian is derived for a zigzag carbon nanotube with an arbitrary number of weak electron-electron charge and spin interactions, which become significant in ultraclean systems. The renormalization group and bosonization are used to determine the ground-state phase diagram. Our phase diagram contains some exotic phases which have not previously been predicted in carbon nanotubes with physically possible interaction profiles. Phases of the undoped case include Mott insulators and a variety of density wave states. In the doped case a Tomanaga-Luttinger liquid is possible.

Electrocatalytic Reduction Of Carbon Dioxide By Cobalt-Phthalocyanine-Incorporated Polypyrrole, Jun Chen, Gordon G. Wallace, Jiaxing Lu, Aijian Zhang, Weimin Zhang

Faculty of Science - Papers (Archive)

In the quest for catalysts for the electrocatalytic reduction of , a cobalt phthalocyanine/polypyrrole (CoPc/PPy) composite electrode has been developed. The electrode is prepared by drop casting CoPc onto the PPy film from the CoPc/tetrahydrofuran solution (1 mg/mL). The onset potential for reduction occurred at potentials 160 mV more positive than observed with a simple PPy electrode. Furthermore, in the potentiostatic electrolysis, the catalytic current for reduction at CoPc/PPy was very stable, with a higher current density and current efficiency when compared to the PPy electrode.

Influence Of Shielding Gas On Fume Formation Rate For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel, Kristin R. Carpenter, Brian J. Monaghan, John Norrish

Faculty of Engineering - Papers (Archive)

Shielding gas composition is an important parameter for successful gas metal arc welding (GMAW) and has been shown to affect the fume formation rate (FFR). The present paper compares thirteen shielding gases and their impact on FFR in spray transfer. In Ar-based mixtures, increasing CO2 had a greater impact than raising O2 on FFR. When O2 was increased in ternary mixtures, the FFR increased for Ar-5%CO2 but no discernable increase was observed for the Ar-12%CO2 mixtures. Ar-He-CO2 mixtures had the most stable FFR's. The FFR for 100% CO2 was significantly higher due to the change in weld transfer mode to …

Analysis Of Fume Formation Rate And Fume Particle Composition For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel Using Different Shielding Gas Compositions, Kristin R. Carpenter, Brian J. Monaghan, John Norrish

Faculty of Engineering - Papers (Archive)

The present paper compares thirteen shielding gases and their impact on FFR and fume particle while welding in the spray transfer regime. There was no obvious influence from the shielding gas on particle composition and fume particles were identified as (Fe,Mn)3O4. There was a slight peak shift that indicated that small levels of Mn, as detected by TEM-EDS, substituted for Fe in the Fe3O4 phase. Shielding gas composition is an important parameter for successful gas metal arc welding (GMAW) and has been shown to affect the fume formation rate (FFR). In Ar-based mixtures, increasing CO2 had a greater impact than …

The Live Monitoring Of Carbon Emissions For Sustainable International Trade And Exchange, Lee Styger

Sydney Business School - Papers

There is growing hypothesis that, following the current economic crisis, carbon trading will kick start the stock markets once again and that carbon is a new “commodity” albeit now being traded in a traditional way. This carries several disadvantages; the most pressing being that “if you can’t measure it then you cannot improve it”, rendering any audit meaningless as a real improvement measure and resulting in the view that carbon trading is merely another form of taxation. This paper will discuss the options of live monitoring and recording of trade waste resources and offer a framework for viable trading of …

Towards Novel Entangled Carbon Nanotube Composite Electrodes, Gordon G. Wallace, P. Sherrell, J. Chen, A. Minett

Faculty of Science - Papers (Archive)

The commercialization of carbon nanotube electrodes is impeded by the lack of bulk processing techniques. One approach to overcome this impediment is the growth of macroscopic CNT composite architectures which do not require any extra processing. Unfortunately the fundamental growth mechanisms of these carbon composites is not currently understood. To probe this mechanism a systematic examination of the effect of certain growth parameters was undertaken. Within this paper we present the promising preliminary findings of this study revealing extremely complex relationships between variables during growth. We also present the performance of the produced architectures as capacitor electrodes and the further …

Development And Application Of A System For The Analysis Of Atmospheric, Water And Sediment Nitrogen And Carbon, Ann Stavert, Stephen R. Wilson, Dianne F. Jolley

Faculty of Science - Papers (Archive)

Eutrophication and climate change, key environmental concerns, are both linked to the carbon and nitrogen cycles hence the improved understanding of these cycles is essential. Currently, there is no system that simultaneously measures the fluxes of the three key gas phase products of nitrogen and carbon cycling (CO2, CH4 and N2O) in submerged ecosystems with hourly time resolution. A “Lake-in-a-box” (mesocosm) was developed in the laboratory which allowed the monitoring of key components of the carbon and nitrogen cycles within the air, water and sediments. The approach is automated, simple and time efficient and novel in its ability to examine …

Holocene Carbon Burial By Lakes In Sw Greenland, N. J. Anderson, W. D'Andrea, Sherilyn C. Fritz

Department of Earth and Atmospheric Sciences: Faculty Publications

The role of the Arctic in future global change processes is predicted to be important because of the large carbon (C) stocks contained in frozen soils and peatlands. Lakes are an important component of arctic landscapes although their role in storing C is not well prescribed. The area around Kangerlussuaq, SW Greenland (66–68°N, 49–54°W) has ex¬tremely high lake density, with ~20 000 lakes that cover about 14% of the land area. C accumulation rates and standing stock (kg C m⁻²), representing late- to mid-Holocene C burial, were calculated from AMS ¹⁴C-dated sediment cores from 11 lakes. Lake …

Spatial-Temporal Responses Of Louisiana Forests To Climate Change And Hurricane Disturbance, Fugui Wang

LSU Doctoral Dissertations

This dissertation research focused on three questions: (1) what is the current carbon stock in Louisiana’s forest ecosystems? (2) how will the biomass carbon stock respond to future climate change? and (3) how vulnerable are the coastal forest resources to natural disturbances, such as hurricanes? The research utilized a geographic information system, remote sensing techniques, ecosystem modeling, and statistical approaches with existing data and in-situ measurements. Future climate changes were adapted from predictions by the Community Climate System Model on the basis of low (B1), moderate (A1B), and high (A2) greenhouse gas emission scenarios. The study on forest carbon assessment …

Successional Change In Phosphorus Stoichiometry Explains The Inverse Relationship Between Herbivory And Lupin Density On Mount St. Helens, Jennifer L. Apple, Michael Wink, Shannon E. Wills, John G. Bishop

Biology

Background: The average nitrogen-to-phosphorus ratio (N:P) of insect herbivores is less than that of leaves, suggesting that P may mediate plant-insect interactions more often than appreciated. We investigated whether succession-related heterogeneity in N and P stoichiometry influences herbivore performance on N-fixing lupin (Lupinus lepidus) colonizing primary successional volcanic surfaces, where the abundances of several specialist lepidopteran herbivores are inversely related to lupin density and are known to alter lupin colonization dynamics. We examined larval performance in response to leaf nutritional characteristics using gelechiid and pyralid leaf-tiers, and a noctuid leaf-cutter. Methodology/Principal Findings: We conducted four studies. First, growth of larvae …

Evaporation And Carbon Dioxide Exchange By Sugar Cane Crops, G Bryant, Travis A. Naylor, Stephen R. Wilson, O T Denmead, David W. Griffith, B.C.T. Macdonald, I. White

Faculty of Science - Papers (Archive)

RECENT developments in water and carbon trading and biofuel production highlight the need to document the water and carbon balances of Australia’s cropping systems including sugarcane. This paper presents the results of studies of evaporation and CO2 exchange throughout the growing seasons of two sugarcane crops, a 1st ratoon crop at Murwillumbah where burnt-cane was practised and a 5th ratoon crop at Mackay where trash blanketing was employed. At both locations, a micrometeorological eddy covariance technique was employed to measure water vapour and CO2 exchange between crop and atmosphere and manual and automatic chambers to measure CO2 emission from the …

Carbon-Nanotube Biofiber Microelectrodes, Carol M. Lynam, Gordon G. Wallace, Willo Grosse

Faculty of Science - Papers (Archive)

All-biocompatible carbon-nanotube fibers were formed using wet spinning. In this process the spinning solutions used are carbon nanotubes dispersed using biomolecules such as hyaluronic acid and chitosan. We compare the effect of a coagulation bath containing either a polymer binder, e.g., polyethyleneimine, or simply a precipitating solvent system, e.g., acetone. The electrical, mechanical, and morphological properties of the resulting fibers were studied. Biocompatible electrode structures were generated suitable for a variety of biomedical applications, e.g.,in biosensors or in systems where the application of an electrical field is advantageous e.g., stimulation of electrically excitable cells such as nerve and muscle cells.

Carbon Nanotube Network Modified Carbon Fibre Paper For Li Ion Batteries, Jun Chen, Jiazhao Wang, Andrew I. Minett, Yong Liu, Carol M. Lynam, Hua-Kun Liu, G G. Wallace

Faculty of Engineering - Papers (Archive)

Here we report on the direct deposition of large quantities of highly porous carbon nanotube networks onto a carbon fibre paper support; subsequently utilised as the anode in a Li-ion battery application showing improved long-term performance and chemical stability with a significant fully reversible capacity of 546mAh/g.

Modelling The Stability Of A Very Large Cave Chamber; Case Study: Brezno Pri Medvedovi Konti, Jože Koritnik, France Šušteršič

KIP Articles

The big chamber in Brezno pri Medvedovi konti (Julian Alps, Slovenia), about 150 m wide, over 50 m high and with a volume of about 62 x 104 m3, is the second largest cave chamber yet discovered in Slovenia. Application of FLAC computer software enabled modelling of the stability of the chamber’s arched roof during hypothetical denudational lowering of the overlying surface. Modelling was based on two sets of rock property parameters generally attributed to the local parent rock. In both cases the modelled deformation within the arch was at a minimum at a residual ceiling thickness of 20 to …

The Solitary Attempt: International Trade Law And The Insulation Of Domestic Greenhouse Gas Trading Schemes From Foreign Emissions Credit Markets, Elias Leake Quinn

University of Colorado Law Review

This Comment examines the influence of international trade agreements on the implementation of a hypothetical, domestically- scaled cap-and-trade scheme to facilitate greenhouse gas emissions reductions in the United States. Several areas of intersection are examined, including the contemplation of the credits as commodities for trade and the construction of measures designed to offset any competitive disadvantage such a system might put on domestic companies. The Comment concludes that a domestically-scaled cap-and-trade scheme, while an important step in mitigating global climate change, is vulnerable to challenges under existing international trade agreements. Such challenges, if successful, may in turn drive the convergence …

Lessons Learned From The European Union’S Climate Policy, David Hunter

Articles in Law Reviews & Other Academic Journals

INTRODUCTION The United States, after ignoring climate policy for the last decade, now finds itself debating the merits of a national cap-and-trade policy. Currently, U.S. environmentalists are divided over whether to support the watered-down American Climate and Energy Security bill (ACES), also known as the Waxman-Markey bill. ACES passed the U.S. House of Representatives only after significant changes were made to address concerns from the coal industry and other powerful forces; and the bill likely faces even more compromises if it is to be passed in the U.S. Senate.' Supporters of the Waxman-Markey bill believe it is best to establish …

Soil Carbon And Nitrogen Accumulation In A Forested Debris Flow Chronosequence, California, Judith K. Turk, Robert C. Graham

Conservation and Survey Division

The role of forest soils in the biogeochemical cycling of C and N is most dynamic during the early stages of soil development. To define C and N trends that occur with soil development in a mixed coniferous forest, a chronosequence formed by debris flows was studied. The accumulation rates of total organic C (TOC) and total N (TN) were evaluated in soils on 10 debris flow deposits, ranging from depth, since this was the depth of the shallowest debris flows. Carbon was found to accumulate in the organic horizons at a rate of 26.5 g m⁻² yr^{−1 …}