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Performance Of Nitrogen As A Carrier Gas In Capillary Gas Chromatography Using A Thin Film Column, Brittany A. Handzo

Seton Hall University Dissertations and Theses (ETDs)

Gas chromatography (GC) is one of the most widely used analytical techniques for the separation and analysis of volatile compounds. Solids, liquids, and gases, organic and inorganic materials, and large molecular weight compounds can all be analyzed via this technique. Gas chromatographic separations are fast, accurate, and reliable. One of the reasons why these separations are so efficient is because of the carrier gas. The purpose of the carrier gas is to carry the injected sample through the column. It is known as the mobile phase and does not interact chemically with the sample. Common carrier gases include helium, hydrogen, …

Multi-Platform Comparison Of Canopy Reflectance On Corn Whole Plant And Leaf Tissue Nitrogen Status, Zachary Thomas Sumner

Theses and Dissertations

Single-rate blanket application of fertilizer nitrogen (N) can result in an over or under application. Variable rate (VR) applications tailored to actual crop demands can improve N use efficiency in spatially variable soils. The objective of this study was to compare and improve relationships derived between corn canopy reflectance and corn N status acquired with two sensing platforms. Four fertilizer N rates were used, from deficient to excess, to create varying corn N status. Sensing and biophysical sampling was taken throughout the season for analysis and comparison to calculated vegetation indices (VIs). Results show strong relationships between VIs and corn …

Characterizing Dryland Ecosystems Using Remote Sensing And Dynamic Global Vegetation Modeling, Abdolhamid Dashtiahangar

Boise State University Theses and Dissertations

Drylands include all terrestrial regions where the production of crops, forage, wood and other ecosystem services are limited by water. These ecosystems cover approximately 40% of the earth terrestrial surface and accommodate more than 2 billion people (Millennium Ecosystem Assessment, 2005). Moreover, the interannual variability of the global carbon budget is strongly regulated by vegetation dynamics in drylands. Understanding the dynamics of such ecosystems is significant for assessing the potential for and impacts of natural or anthropogenic disturbances and mitigation planning, and a necessary step toward enhancing the economic and social well-being of dryland communities in a sustainable manner (Global …

Strategies To Improve Forage Utilization By Sheep Offered Forage Mixtures, Valens Niyigena

Graduate Theses and Dissertations

In the first experiment, alfalfa and novel endophyte-infected tall fescue (NE+) forages were harvested after a killing frost, then mixed to formulate 4 different treatments; alfalfa alone, 67% alfalfa +33% fescue, 33% alfalfa + 67% fescue, or 100% fescue. After 3 months of storage as silage, Dorper ewe lambs (n = 20; mean BW = 34.7 ± 6.65 kg) were fed silage for ad libitum consumption, using 5 animals per treatment. Increasing the proportion of NE+ tall fescue improved (P < 0.05) silage total acids and lactic acid concentrations and decreased silage ammonia concentration. Digestible dry matter and organic matter intake and nitrogen utilization parameters decreased with increasing inclusion of NE+ in diet. In the second experiment, 16 Dorper ewe lambs (41.8 ± 4.61 kg BW) were assigned to 4 different treatments; alfalfa silage alone (0 g/kg; CONT) or alfalfa silage mixed with chopped sericea lespedeza (SL) hay to provide 90 (LOW), 180 (MED), or 270 g/kg SL (HIGH) on a dry matter basis in a randomized complete block design experiment with 2 period to provide 4 observations per treatment for each experimental period. Increasing the proportion of sericea lespedeza in the diet decreased dry matter and organic matter digestibility but did not affect feed intake. Fecal nitrogen (g/kg N intake) increased linearly (P < 0.01) while urinary N (g/ day and g/ kg of N intake) tended to decreased linearly and quadratically (P ≤ 0.1) with increasing the proportion of SL in diet. In the third experiments, 16 gestating Dorper ewe lambs (49.1 ± 4.61 kg BW) were allocated to 4 treatments; alfalfa silage alone (0% g/kg; CONT) or alfalfa silage mixed with lablab purpureus(LP) hay to provide 90 (LOW), 180 (MED), or 270 g/kg LP (HIGH) on a dry matter (DM) basis, in a randomized complete block design experiment with a total 8 replication per treatment. Supplementation of LP in diet increased quadratically (P ≤ 0.04) forage dry matter, organic matter intake, digestible dry matter and digestible organic matter intake (P < 0.05). Nitrogen apparently absorbed and urinary N both decreased linearly (P < 0.01) with adding more LP hay in diet. Harvesting and mixing alfalfa and fescue after a killing frost improved silage fermentation characteristics and supplementation of tannins from SL and polyphenol from LP altered N excretion.

Key words: lablab, sericea lespedeza, alfalfa silage, nitrogen, sheep.

The Role Of Sediment Resuspension In Estuarine Inorganic Nutrient Cycling, Kirsten Jo Ayres

Theses and Dissertations

Time-scaling of estuarine inorganic nitrogen cycling contains many assumptions due to biogeochemical interactions. Nitrogen, often a limiting factor for primary production, is transformed and utilized by many estuarine organisms. Inorganic nitrogen is especially high in porewater. High nutrient pore water, contained within the interstitial spaces of sediment, has been assumed to influx high concentrations of inorganic nutrients into surface waters during resuspension events. These short-term resuspension events rapidly introducing high concentration of nutrients into the water column. In order to determine the internal time scale of inorganic nitrogen cycling, a box-model nutrient budget, horizontal in situ transects, and vertical nutrient …

Viability Of Wetland Crops For Use In Treatment Wetlands: Nitrogen Removal From Water And Production Of Food, Andrew Denson Corder

Theses and Dissertations

Treatment wetlands are used to treat wastewater from a variety of sources, but their functionality depends on the macrophytes present therein. To better understand the viability of wetland macrophytes both as sources of food and as agents of nitrogen removal from wastewater, this study quantified plant growth, food production, and nitrogen removal capacity of three common wetland crops as well as three locally dominant graminoid species in a variety of relevant ecological contexts. All six plant species and a control were grown over a ten-week period in three related experiments: (1) under three moisture regimes, (2) with or without competition …

Identifying The N Sources For Black Mangrove (Avicennia Germinans) In A South Texas Mangrove Forest, Ashley Elizabeth Murphy

Theses and Dissertations

Black mangrove (Avicennia germinans) in south Texas provide ecosystem services and benefits to humans including: habitat for wildlife, prevention of coastline erosion, and mitigation of natural disasters. One step to preserve their ecological functions is to identify and protect the source of their nitrogen (N). Nitrogen stable isotopes were sampled for one year beginning August 2018 and used as tracers to identify how mangroves obtain N. Total N in (A. germinans) and associated (Batis maritima) (plants) (2.1%) was more abundant than in cyanobacteria (0.6%) and sediment (0.1%). Plant d15N signatures (5.52‰) were more similar to sediment (5.21‰) than cyanobacteria (1.98‰), …

Reconstructing Geographic And Trophic Histories Of Fish Using Bulk And Compound-Specific Stable Isotopes From Eye Lenses, Amy A. Wallace

USF Tampa Graduate Theses and Dissertations

The present research examined the viability and utility of eye lenses as a source of lifetime stable-isotope records in fish. It is presented in three sections. The first section compared bulk isotopic variation (bulk analysis) within fish eye-lenses at two temporal resolutions and compared patterns obtained from left and right eyes. The first temporal resolution was lower in an attempt to expose broad-scale isotopic changes during life while reducing effort and cost. This approach did reveal lifetime patterns, but tended to miss certain life events, particularly during early life. The second resolution was higher and provided detail that was missed …

Life History Through The Eyes Of A Hogfish: Evidence Of Trophic Growth And Differential Juvenile Habitat Use, Meaghan E. Faletti

USF Tampa Graduate Theses and Dissertations

Understanding ontogenetic linkages among fish habitats is critical for conservation of fish populations and the ecosystems on which they rely. Natural tags such as stable isotopes are an effective tool commonly used to investigate ecological questions regarding fish movement and habitat use. Here, I analyzed stable isotopes from the sequentially deposited laminae of Hogfish (Lachnolaimus maximus) eye lenses from the eastern Gulf of Mexico (eGOM) to investigate trophic and geographic changes across individual life histories. I documented evidence of entire-life scale trophic growth through increases in δ15N. I also observed depth separation at the juvenile stage, evidenced by variation in …

Rice (Oryza Sativa) Response And Management Following Exposure To Sub-Lethal Rates Of Non-Target Herbicides, Benjamin Lawrence

Theses and Dissertations

Research was conducted at the Mississippi State University Delta Research and Extension Center from 2015 to 2018 to (1) determine the effects of sub-lethal concentrations of paraquat, metribuzin, fomesafen, and cloransulam-methyl applied at different rice growth stages, determine the effects on rice growth of simulated off-target paraquat applications at varying concentration based on a proportionally decreased carrier volume characterize rice response to a sub-lethal concentration of paraquat in combination with common POST and residual herbicides, assess whether starter N fertilizer or different N fertilizer management strategies can aide in rice recover after exposure to a sub-lethal concentration of paraquat, and …

(Meso-Tetra(N-Methyl-4-Pyridyl)Porphyrin)Manganese(Iii) Iodide: A Water Stable Catalyst For The Aziridination Of Olefins, Daniel Karl Wolgemuth

Theses and Dissertations

Aziridines are important building blocks for the synthesis of a wide range of organic compounds, including biologically active compounds and pharmaceuticals. The development of more cost-effective catalysts for atom transfer reactions is a continuing area of research in chemistry. Transition metal complexes have been shown to catalyze the aziridination of olefins, however, most require expensive metal ions or complex ligands. Meso-tetra(N-methyl-4-pyridyl)porphyrin (TMPyP4) is a highly charged, planar ligand that has been used to support manganese(III) in complexes like Mn[TMPyP4]I5. Herein we report the optimization of the reaction conditions for the aziridination of olefins in water and buffered solutions catalyzed by …

Assessing The Agronomic And Ecological Relevance Of Mineral-Associated Organic Matter, Andrea Jilling

Doctoral Dissertations

As the largest terrestrial sink for carbon (C) and a critical source of nitrogen (N) for plants, soil organic matter (SOM) is a major driver of ecosystem function. It is critical to understand the mechanistic controls on SOM in order to improve models of global C cycling and to develop accurate measures of soil fertility. SOM consists of a wide spectrum of compounds, varying in chemical characteristics and function. The chemical and physical fractionation of SOM is a valuable tool for distilling this complexity into meaningful and distinct pools: detrital or particulate organic matter (POM), which contains mostly recent litter …

Spatial And Temporal Variation In The Diet Composition Of Zooplankton In Mission Bay, Bryanna Paulson

Theses

Analyses of quantitative data on zooplankton diets are vital for understanding the drivers of zooplankton abundance within an ecosystem. Such analyses also provide insight into trophic pathways within the lower planktonic food web, which support populations of higher trophic level species. This study used carbon and nitrogen stable isotope ratios of size-fractionated plankton in Mission Bay, San Diego, CA to examine the spatial and temporal variation in zooplankton trophic ecology and determine potential environmental drivers of zooplankton community structure. Carbon stable isotopes reflect primary production sources in an organism’s diet, and nitrogen stable isotope ratios can be used to estimate …

Significance Of The Rates Of Atmospheric Deposition Around Utah Lake And Phosphorus-Fractionation Of Local Soils, Joshua Glen Reidhead

Theses and Dissertations

Eutrophic Utah Lake receives a large nutrient load from a variety of sources, includingtreated wastewater discharges, runoff and tributaries, recycling from bottom sediments andAtmospheric Deposition (AD). AD was the focus of this study and was comprised of twocomplementary parts. First was a study of nitrogen and phosphorus depositions from theatmosphere, and second was a study of phosphorous as contained in soils near Utah Lake viafractionation methods.The soil samples were found to contain approximately 1,000 mg-P/kg soil for totalphosphorus (TP). A separate phosphorus (P) fractionation gave slightly higher values, excludingthe residual P, we are 95% confident that one gram of sample …

Improved Estimates Of Tributary Nitrogen Load To Casco Bay, Maine, Whitley J. Gray

Electronic Theses and Dissertations

Over the past two decades, total nitrogen (TN) concentrations have increased in Casco Bay (CBEP 2015). The sources of the increased nitrogen are poorly understood but occur with simultaneous population growth and land use changes. The total riverine nitrogen load to Casco Bay was previously estimated by Liebman and Milstead (2012) using the United States Geologic Survey’s (USGS) SPAtially Referenced Regression On Watershed attributes (SPARROW) model. The SPARROW model uses watershed characteristics, regional monitoring data and nitrogen source data to estimate nitrogen loading but was not validated using measurements of nitrogen in the Casco Bay watershed. This study attempts to …

Influence Of Varying Inorganic Nutrients Supply On Ergosterol And Glucosamine Concentrations And Biomass Nutrient Stoichiometry In Ectomycorrhizal Fungi, Stephanie S. Koury

Master's Theses

Ectomycorrhizal (ECM) fungi are critical for the health of forest ecosystems where they can sequester large amounts of carbon in the form of soil organic matter, a matter of growing interest due to anthropogenic climate change. A clear understanding of their growth dynamics and responses to environmental changes is imperative for future work in forest management and the possible mitigation of increased atmospheric CO₂. Six ECM fungal species were grown in liquid culture under varying nitrogen and phosphorus concentrations and ratios to assess how exogenous nutrient supplies affect fungal biomass stoichiometry and the degree of elemental homeostasis. Additional …

Fertilizer And Paclobutrazol Effects On Petunia Production And Post-Production Performance, Jiwoo Park

All Theses

Reducing the amount of fertilizer applied to the plants in ornamental plant production industry is a growing trend due to rising environmental concerns; however, reduced fertilization can result in the failure to supply the retail customer with a plant that contains enough nutrients to sustain further growth in the consumer environment where fertilizer application is frequently lacking. Therefore, the objective of the first study was to examine alternative fertilizer delivery strategies that can maintain petunia quality during greenhouse production and continue to sustain plant growth and flowering in the post-production consumer environment. The fertilizer treatments applied to the plants were …

Effect Of Unique Cover Cropping Strategies On Soil Nitrogen Dynamics And Their Rates Of Nitrogen Release, Manuel Sabbagh

Masters Theses

There is limited knowledge concerning the effects of multi-species cover crops (CC) on soil nitrogen (N) dynamics in the row-crop systems of the southeastern US. This study was conducted with two objectives: (i) to determine the rates of in-situ CC residue decomposition and N release in response to CC species and degree of soil contact, and (ii) to understand the seasonal changes in soil N pools across different CC treatments compared to a CC-free control at different soil depths. Based on a 21-week in situ litterbag experiment, CC residue decomposition rates and N release were determined. Litterbags were either placed …

Development Of The Electrohydromodulation Process For Simultaneous Recovery Of Nitrogen And Phosphorus From Municipal Wastewater, Mahamalage Kusumitha Perera

Open Access Dissertations

The demand for phosphorous (P) fertilizer is projected to increase by 100% by the end of the century, and the use of nitrogen (N) fertilizer is increasing exponentially as well. Current single-use nutrient management practices have led to environmental impacts of mining, extensive greenhouse gas emissions and surface water eutrophication. Recovery and reuse of nutrients would reduce solubilizing plant available N and P in the environment. Thus, the embedded energy in fertilizer production can be retained while minimizing the conversion of stable forms of N and P. Wastewater was identified as a potential source to recover nutrients, as wastewater contains …

Limitations To Photosynthesis In Silver Bow And Blacktail Creeks, Isaiah Robertson

Graduate Theses & Non-Theses

Throughout Silver Bow Creek’s history, consideration of the photosynthetic communities that make heterotrophic life possible have often been overlooked since macroinvertebrates made up a majority of ecosystem health assessments. Silver Bow Creek has had minimal biological research outside of macroinvertebrate surveys, especially as it pertains to photosynthetic organisms. This study assessed the photosynthetic communities of Silver Bow Creek and their limitations by limiting available light and comparing uptake of nutrients during a 23-day incubation experiment conducted at four sites along the flow of Silver Bow Creek and Blacktail Creek. At each site, nine one-liter microcosms, filled with creek water and …

Measuring Nitrogen Transformation In Wastewater Impacted Streams Using In-Situ Benthic Chambers, Makenzi Beltran

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Acrylic chambers and metal frames were installed at the sediment-water interface of streams impacted by the effluent from wastewater reclamation facilities in order to determine nitrogen rates for nitrification, denitrification, assimilation, ANAMMOX, and DNRA. Each chamber was dosed with an isotopic form of nitrate (¹⁵NO₃^-), and both isotopic (¹⁵N) and non-isotopic (¹⁴N) samples were collected. The project locations included East Canyon Creek near the East Canyon Wastewater Reclamation Facility in Park City, Utah and Box Elder Creek near the Brigham City Wastewater Treatment Plant in Brigham City, Utah. Separate chamber measurements …

Imprints Of The Land: Spatial And Temporal Connections Between Land Use And Water Quality, Janet Barclay

Doctoral Dissertations

Human activity and land use patterns are altering solute concentrations in waterbodies worldwide, frequently with effects that are delayed and/or displaced from their cause. Understanding the resulting water quality trends allows managers to tailor interventions and preemptively respond to likely future conditions. My research addressed two broad questions:

1) How and why does surface water quality vary spatially?

Many U.S. states classify waterbodies according to groups of designated uses, suggesting that water quality and classifications are correlated. The relationship between classification and water quality, however, is untested. I analyzed existing data for the State of Connecticut to identify differences in …

Ecophysiology Of Ponderosa Pine Seedlings After Severe Fire: The Effect Of Tree Canopy, Lauren M. Bansbach

Biology ETDs

Ponderosa pine forests evolved with low-severity surface fires to maintain forest structure and process. However, increasingly common high-severity fires often result in complete overstory canopy loss and a shift from forest to shrub- and grass-dominated vegetation that may persist as an alternate stable state due to limited rates of ponderosa seedling regeneration in severely burned areas. Though overstory tree canopy is an important driver of understory plant response, little is known about how the absence of tree canopy following severe fires interacts with changes in year-to-year climate to affect the physiological function of ponderosa pine seedlings. This field study tested …

Nutrient Limitation Of Phytoplankton In Lake Wateree, South Carolina: Implications For Future Water Quality Management, Kara M. Clyburn

Theses and Dissertations

Cultural eutrophication is a primary contributor to phytoplankton production in freshwater lakes from excess anthropogenic nutrient inputs, and resulting impacts on water quality, aquatic ecosystems, human and animal health are increasing worldwide. Understanding the factors that limit phytoplankton growth is an important strategy for identifying and managing nutrient sources and successfully controlling the over- enrichment of nitrogen (N) and/or phosphorus (P) in freshwater lakes. The Redfield molecular ratio of carbon (C), N and P maintains that the C:N:P molar ratio is 106:16:1 when nutrients are not limiting, and the ecosystem is balanced. A N:P molar ratio > 20:1 tends to be …

Dissolved Inorganic Nitrogen Dynamics In Swash Zone Sands Of Long Bay, Sc, Alexis F. Echols

Honors Theses

A key component affecting the biogeochemistry of the sedimentary environment is pore water between grains of sediments. Sedimentary microorganisms are constantly modifying chemical compounds as part of their life functions which are then exchanged between the sediment column and the overlying water column. Dissolved inorganic nitrogen, a major element for life, takes on several forms including nitrate, nitrite, and ammonium which vary in concentration throughout the sediment and with respect to each other. The relative concentrations of these nitrogen species have been previously briefly explored in sandy columns, where redox gradients that control their relative concentrations can be fairly deep …

Nitrogen And Phosphorus Uptake In An Urban Stream Ecosystem, Nicolette A. Sheffield

Theses and Dissertations

Urban stream ecosystems are faced with high input levels of nitrogen (N) and phosphorus (P) from anthropogenic activities. N and P are important to plant growth and stream health; however, high levels can lead to algal blooms and eutrophication, a harmful effect to both aquatic life and water quality. Common urban sources of N and P include fertilizer, atmospheric deposition, stormwater outfall, and leaf-litter decomposition. Common urban stream features such as a flashier hydrograph, altered channel stability and morphology, increase in nutrient output (such as N and P), and heat retention, have been shown to result in an overall decrease …

Final Design Review: Wear Test Machine, Justin Ju-Han Hou, Abraham Jack Mitchell, Alexandra Denae Pavano, Jahyun Kaylla Son

Mechanical Engineering

A California Polytechnic State University Senior Project team has been tasked by Marvin Engineering Co. to design and build a friction wear test fixture; the fixture is to characterize the coefficient of friction and potential friction wear of various industry adopted metal pairings in an oxygen-free environment. This final design review serves to document project research, full design process, method of operation of final product, and a comprehensive testing procedure.

The R&D department at Marvin Engineering Co. proposed this investigation in order to explore the phenomenon of friction and adhesive wear, specifically the occurrence of galling between stainless steel surfaces. …

The Role Of Small Reservoirs In Reducing Reactive N Export Via Denitrification, Margaret Phillips, Wil Wollheim

Honors Theses and Capstones

Reactive nitrogen (N), which harms ecosystem health, has been increasing in the biosphere, leading to higher N export to coastal ecosystems. Although man-made reservoirs can be significant sources of greenhouse gases, they can also retain N, thus reducing N export. Because many dams are relics from industrial hydropower, their removal is becoming increasingly common. It is therefore crucial to understand the ecological tradeoffs of man-made reservoirs. While previous studies have examined nutrient budgets and denitrification at inputs and outputs of large reservoirs, small reservoir dynamics remain understudied. In this study, we measured inputs and outputs of NO₃ and N …

Impact Of A Winter Rye Cover Crop On Edge-Of-Field Nutrient Losses And Corn Silage Production, Keegan Griffith

Graduate College Dissertations and Theses

Cover crops have the potential to reduce environmental impacts of corn production. The objective of this study was to quantify differences in nitrogen (N) and phosphorus (P) loading between corn plots with or without a winter rye cover crop (Secale cerale). Four field plots (30 x 46 m) in Chazy, NY with edge-of-field monitoring were used for the study. Two plots were randomly assigned a rye cover crop treatment and planted with a grain drill at a rate of 112 kg ha-1 after corn silage harvest in 2015 and 2016. Continuous water flows were monitored from surface runoff and tile …

Nutrient Removal Performance Of A Wood Chip Bioreactor Treatment System Receiving Silage Bunker Runoff, Deborah Joy Kraft

Graduate College Dissertations and Theses

Silage bunker runoff is a form of agricultural pollution that contributes to aquatic ecosystem degradation. Current handling and treatment methods for this process wastewater are often ineffective or expensive. A woodchip bioreactor is an emerging treatment technology designed to facilitate denitrification through the provision of an anaerobic, carbon rich environment. A wood chip bioreactor treatment system, consisting of three pre-treatment tanks, two wood chip bioreactors, and one infiltration basin, was constructed at the Miller Research Complex in South Burlington, Vermont in 2016. Runoff and leachate from an adjacent silage storage bunker is directed into the system. The pre-treatment tanks include …