An Assessment of North Carolina's Future Electricity System Under Uncertainty

Li, Binghui North Carolina State University ProQuest Dissertat 2018 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Electricity generation represents the largest share of carbon dioxide emissions across all energy sectors in North Carolina. Despite the rapid expansion of renewable energy over the past decade, the share from all renewable energy sources in Nor. As one of the only two locations with near-shore access to the Gulf Stream, North Carolina can potentially employ Gulf Stream energy as a low-carbon electricity source. However, rigorous techno-economic assessment is required to determine whethe. This thesis provides a comprehensive techno-economic assessment of ocean turbines operating in the Gulf Stream off the North Carolina coast and a state-level analysis of the North Carolina electric power sector through 2050. This thesis fulfills. In addition, a diverse set of methods are utilized to address future uncertainties faced in this study. A portfolio optimization model is developed to reduce variations associated with Gulf Stream electricity output. In the state-level electrici. The thesis work suggests the following high-level insights. The techno-economic analysis in Chapter 2 indicates that the lowest levelized cost for a single 16 MW site can reach 400 $/MWh. The portfolio optimization demonstrates that geogr.

"The Millennium of Their Glory": Public Memory and War Monuments in North Carolina, 1865-1929

Laws, William Christopher North Carolina State University ProQuest Dissertat 2022 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

“The Millennium of Their Glory” investigates how North Carolinians cultivated memories of the Civil War in order to promote specific public interpretations and ideals. Between 1865 and 1929, state governments, politicians, memorial associations, fraternal organizations, and individual community members created public memories and found purpose for them. This study considers memory-making as a process, rather than a product, and explores the emerging culture war fought over North Carolina’s Civil War memory, which saw wartime anti-Confederate sentiments and vernacular memories obliterated in favor of a consensus, White reconciliation official memory. In addition to a thorough examination of Confederate monumentalism during this era, “The Millennium of Their Glory,” analyzes North Carolina’s history with non-Confederate Civil War commemoration and memory-making. Union monuments placed in the state exemplified a meshing of Confederate and American values into a new White American identity. This process took place completely within the framework of the Lost Cause— a seamless blend of Lost Cause and Cause Victorious doctrines, which shaped the war memory in ways that minimized the causes of the war and eliminated Black Americans’ contributions, voices, and memories. At the turn of the twentieth century, North Carolina Confederate memorialists even managed to assimilate new American heroes, like Worth Bagley, who died for the Stars and Stripes thirty years after the fall of the Stars and Bars, into Confederate lore. In this respect, southerners were not simply defending and protecting old Confederate ideals, but were actively asserting new expectations into American culture, giving birth to new forms of White nationalism that the North endorsed and shared.

Agricultural Commodity Prices

Thompson, Robert Stanley North Carolina State University ProQuest Dissertat 2021 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

The two essays of this dissertation investigate the determinants of agricultural commodity prices, more specifically those for field crops. Risk is a common theme in agriculture, largely due to the nature of agriculture itself. Farmers make large investments throughout the growing season without knowing with certainty the prices for which they will sell their crop, the size of which is also subject to uncertainty. Those with obligations to purchase these agricultural commodities also face these risks. It is important to develop forecasts of the range of prices and quantities buyers and sellers can expect to receive in the future and the probability those prices and quantities are realized. An investigation into the underlying structure of these markets facilitates the development of these forecasts in a manner consistent with basic economics. Chapter one and two are different applications of the same general approach to developing forecasts. Development of forecasting methods begin with simple theoretical models of the market of interest. Simple theoretical frameworks give the forecaster general direction that can be refined further to add certain market nuances conditional on the amount of information available for model estimation.The goal of chapter one is to accurately characterize planting time forecasts of the joint distribution of price and yield at harvest. It is common practice to derive this joint distribution with a disjoint set of methods that are almost entirely data driven. I use a system of supply and demand to show potential problems that arise with these status quo methods and propose solutions to those problems. The result is the derivation of the joint distribution of price and yield that is consistent with a given market structure. I repeat this exercise with several small changes to the system of supply and demand – each of which comes with its own set of limiting assumptions.Chapter two is an investigation into the primary determinants of corn prices in North Carolina. North Carolina is a corn deficit state. The large amount of feed required to feed the hogs, broilers, and turkeys in North Carolina exceeds the amount produced here, so a large amount must be imported from outside sources. Reliable forecasts of corn prices are useful for informing marketing decisions for buyers and sellers of corn in North Carolina. There is a large literature about forecasting local corn prices. However, much of that research focuses on regions that are not similar to the market in North Carolina and it is uncertain whether results found elsewhere are applicable to the grain deficit state of North Carolina. I first investigate the underlying structure of the market in North Carolina. Then, I test some conventional methods for forecasting accuracy and compare the results to novel methods developed based on the specific market structure in North Carolina.

Phenotypic and Genotypic Characterization of Foodborne Commensals and Pathogens from Sheep and Their Abattoir Environment in North Carolina: A Serial Cross-Sectional Study

Atlaw, Nigatu Aklilu North Carolina State University ProQuest Dissertat 2021 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Reports of widespread dissemination of extended-spectrum beta-lactamase (ESBL) E. coli and Salmonella in food animals, retail meats, and humans are available. However, information on ESBLs in small ruminants is limited, particularly in the United States (U.S.). The objectives of these studies were: 1) to investigate the prevalence and antimicrobial resistance (AMR) of extended-spectrum beta-lactamase (ESBL) E. coli and Salmonella in sheep and their abattoir environment in North Carolina, 2) to genotypically characterize ESBL E. coli from healthy sheep and their abattoir environment, and 3) to genotypically characterize AMR determinants in Salmonella recovered from sheep and their abattoir environment. Hence, we conducted a year-round serial cross-sectional study and collected a total of 1128 samples from sheep (n=780) and their abattoir environment (n=348). Sheep samples consisted of feces, cecal contents, carcass swabs, and abattoir resting area feces. Environmental samples consisted of soil samples, lairage swab, animal feed, and drinking water for animals. ESBL E. coli and Salmonella were isolated and confirmed using standard culture methods. We selected one confirmed isolate per positive sample for these studies. Collectively, we analyzed a total of 318 ESBL E. coli (318/1128; 28.2%) and 368 Salmonella (368/1128; 32.6%) isolates. The prevalence of ESBL E. coli and Salmonella was significantly higher in environmental samples (166/348; 47.7% and 228/348; 65.5%) compared to the sheep samples (152/780; 19.5% and 140/780; 17.9%), respectively (P<0.0001). All confirmed isolates were tested against a panel of 14 antimicrobials to elucidate susceptibility profiles. More than 97% of ESBL E. coli were multidrug-resistant (MDR; resistant to ≥ 3 classes of antimicrobials). Most Salmonella isolates (77.2%) were pansusceptible, and 10.1% were MDR. We identified a total of 24 different Salmonella serotypes; the top five serotypes in decreasing order of frequency are S. Agona (19.8%), S. Typhimurium (16.2%), S. Cannstatt (13.2%), S. Reading (13.2%), and S. Anatum (9.6%). Prevalence and percent resistance of ESBL E. coli and Salmonella isolates varied significantly by season and sample type (P<0.0001). Whole-genome sequencing (WGS) (MiSeq Illumina platform) was conducted on 113 ESBL E. coli (64 from sheep and 48 from abattoir environment) and 164 Salmonella isolates (63 from sheep and 101 from abattoir environment). Bioinformatics tools were used to analyze sequence data from both pathogens. In both E. coli and Salmonella of pathogens, AMR determinants demonstrated resistance to aminoglycosides, beta-lactams, phenicols, folate pathway antagonists, tetracyclines, and quinolones. ESBL E. coli isolates distinctively carried genes that confer resistance to macrolides and lincosamides while 37% of Salmonella isolates carried fosA7, a gene known to confer Fosfomycin resistance. This report is the first observation of fosA7 in multiple serotypes of Salmonella in the U.S. Many CTX-M-type beta-lactamase genes detected in ESBL E. coli isolates included blaCTX-M-1, blaCTX-M-14, blaCTX-M-15, blaCTX-M-27, blaCTX-M-32, blaCTX-M-55, and blaCTX-M-65. Other beta-lactamase genes detected included blaCMY-2, blaTEM-1A/B/C, and blaCARB-2. Interestingly, blaTEM-1A and blaTEM-1B were the only beta-lactamase gene types detected in the Salmonella isolates. Twenty-eight and 17 different profiles of plasmid types were detected in ESBL E. coli and Salmonella, respectively. Of these, we observed that most occurred in both sheep and environmental sources of isolates. In addition, we identified 29 and 24 different sequence types (STs) of ESBL E. coli and Salmonella, respectively. The core genome phylogenetic analyses of both pathogens revealed that STs were clustered around seasonal sampling but dispersed across sample types.In conclusion, this is the first comprehensive AMR and WGS report on ESBL E. coli and Salmonella from sheep and their abattoir environment in North Carolina. Our study confirmed that sheep are important reservoirs of AMR ESBL E. coli and MDR Salmonella in the U.S. However, further studies are required to determine associated public health risks.

Interactions Among Climate, Disturbance, and Forests Will Shape Future Landscapes

Robbins, Zachary James North Carolina State University ProQuest Dissertat 2022 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Forests store approximately half of all terrestrial carbon and are crucial to global biogeochemical cycles such as water, nitrogen, and carbon. A key component of mitigating carbon emissions and climate change is the preservation of forested landscapes and reforestation. Forests additionally provide other valuable ecosystem services, such as water purification and retention, air purification, as well as timber, food, and medicine. Forests, and their ecosystem services, are often fundamentally structured by disturbance events such as fire, drought, and insect outbreaks. Disturbances are discrete events that alter the structure and function of an ecological system, on a scale relevant to its organization. These disturbances are an endogenous part of forest succession and have resulted in the evolution of unique assemblages of species that rely on disturbances to persist. Climate change alters the intensity and severity of disturbance regimes away from historical conditions. This alteration occurs either directly through changes to underlying processes that lead to disturbance or indirectly through changes in the composition and response of forests experiencing the disturbance. Disentangling these interactions requires separating out the underlying processes that drive disturbance (to the extent possible) as phenomena are likely to be novel and non-linear under future conditions.Humans are interlocked to and interspersed within the disturbances regimes of forests and therefore need to understand how they will behave in the future and what role humans will play in shaping them. Disturbances can have a wide range of negative economic and societal impacts on forest resources and the communities adjacent to them. As urban areas expand further, we will need to continually assess both 1) how we alter disturbance regimes and 2) our safety from their impacts. However, our ability to manipulate disturbance regimes can also restore historical ecosystem function, and increase the resilience of forests to change. For these reasons, forest managers, policy makers, and society at large need quantifications and forecasts of our interaction with forest disturbance. In this dissertation, I am to improve our ability to quantify and forecast forest disturbances and their ecological impact. This centers around interactions among climate, disturbance, society, and forests. I analyze this two forested landscapes; the first is the Mediterranean mixed conifer forests of the Sierra Nevada in California, United States. In the Sierra Nevada, I focus on understanding the role warming, drought, and forest densification have in amplifying outbreaks of the bark beetle, Dendroctonus brevicomis, and how these interactions will play out under future climates. The second study area is the Southern Appalachian Mountains in the states of Georgia, Tennessee, North Carolina, and South Carolina, United States. This area consists of humid mixed hardwood forest, historically maintained by frequent low-intensity fire. We investigate how the fire regime interacts with the novel ecosystem created by modern fire exclusion, how future climate will impact this fire regime, and how human management may shape the fire regime in the future.

Maladaptive Pain in the Cat

Adrian, Derek Evan North Carolina State University ProQuest Dissertat 2019 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Chronic pain affects over 40% of adult humans in the United States. Few new and effective treatment options are available for these chronic pain sufferers because of a high failure rate (90%) of new therapeutics, perhaps partly stemming from the use of inappropriate, induced animal models. Degenerative joint disease (DJD), a chronic inflammatory and painful condition of the joints, may affect 90% of the 94+ million pet cats in the United States. An estimated 40% of those cats with radiographic evidence of DJD experience pain and disability secondary to the condition. This high prevalence of a naturally occurring painful disease, combined with the cat’s shared environment with humans, makes the cat an attractive model for analgesic research. Developing the cat as a model requires filling gaps in our knowledge of effective analgesics and their pharmacokinetics relevant to clinical use, and developing and refining tools for measuring chronic pain in cats.First, we identified these gaps in our knowledge by reviewing the current status of tools to measure chronic (or maladaptive) pain, and pharmacological data surrounding potential analgesics. These gaps include our ability to detect or monitor pain and disability, in our knowledge regarding analgesic medications, and an inconsistent application of the currently available tools in clinical research.Next, we assessed out ability to detect and measure treatment-associated improvements in pain and disability via a randomized, double-masked, clinical trial evaluating the efficacy of a COX-2 selective non-steroidal anti-inflammatory drug (NSAID), robenacoxib, for the treatment of DJD-associated pain in cats. Our aim was to identify gaps in the translational cat model, and improve treatment options available to veterinarians. We detected modest improvements in both activity and owner assessments of pain and disability. Given that NSAIDs are the mainstay of treatment for DJD across species, we expected more significant results. Although several explanations for our results exist, this study reinforced our observations that the current approaches to measuring chronic pain in cats require refinement and improvement, which includes the need for development of a novel, objective measure.Our next goal was to determine the current prescribing practices of veterinarians for the treatment of chronic musculoskeletal pain in cats, to guide future research into potential analgesics of both veterinary and translational interest. A veterinarian-distributed survey collected data on respondent demographics, medications prescribed, and typical dosing regimens. Gabapentin, a medication without either evidence of analgesic efficacy in veterinary species or pharmacokinetic data relevant to the typical dosing regimen, was prescribed by 71.0% of respondents. Because gabapentin is used for maladaptive pain conditions in people, understanding its efficacy in the naturally occurring chronic pain cat model would benefit veterinary medicine, and would increase our understanding of the translational utility of the cat model.We then investigated the pharmacokinetics of gabapentin in cats because data for longterm dosing was needed. We determined the effects of twice daily oral dosing for two weeks on the drug’s pharmacokinetics, and evaluated the systemic absorption of a transdermal preparation. Repeated oral dosing did not significantly affect drug kinetics; therefore, adjustments are not necessary for chronic administration. We also determined that the transdermal preparation used was poorly absorbed and therefore not a viable dosing strategy.Our final study aimed to develop and evaluate the feasibility, repeatability, and sensitivity of a novel, objective measure of nociception in cats. The nociceptive withdrawal reflex (NWR) test is used in human analgesic research to investigate both central mechanisms of nociception, as well as medications affecting these central processes. We found testing was feasible, and occasionally repeatable; however, we were unable to detect differences between healthy and DJD-affected cats. Future exploration of the NWR requires higher-powered studies.

Computer Simulations of Binary Mixtures of Colloidal Particles

Maloney, Ryan Colin North Carolina State University ProQuest Dissertat 2020 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Mixtures of colloidal particles can assemble into complex structures that could be useful for making multifunctional or reconfigurable materials for biotechnology and electronics applications. The goal of this work is to understand how colloidal particle attributes, such as particle shape and activity, affect the self-assembly behavior of the mixture. We are also interested in understanding how the assembled structures differ from those found in single component systems. Our focus is on mixtures that contain at least one dipolar component. To examine these systems, we use discontinuous molecular dynamics (DMD) and Brownian dynamics (BD) simulation techniques.In our first study, we simulate mixtures of two dimensional (2-D) colloidal rods and discs. Our simulations show that the mixture composition has a large effect on the phase behavior of the systems. We compare the phases formed by the mixtures to those formed by the associated single component systems. Phase diagrams in the area fraction-reduced temperature plane are constructed that delineate the boundaries between isotropic fluid, string-fluid, and percolated network phases. We show that the two species of particles often exist in different states. For instance, the dipolar rods can form a percolated network while the dipolar discs remain in a fluid phase. This suggests that such mixtures could be useful for creating bifunctional materials.In our second study, we simulate mixtures of passive dipolar particles and active soft spheres. Our results show that the mixture composition and active particle velocity strongly affect the types of structures formed. These results offer insight into how colloidal mixtures can be harnessed to provide control during the self-assembly process. We construct phase diagrams in the active particle fraction-Peclet number plane that delineate the boundaries between isotropic fluid, dipolar string-fluid, percolated dipolar network, and phase separated states. Results from this work could aid in the fabrication of out-of-equilibrium structures.Finally, we present work that investigates the behavior of mixtures of passive dipolar particles and active soft spheres in an external magnetic field. We construct phase diagrams in the active particle fraction-Peclet number plane that delineate the boundaries between isotropic fluid, dipolar string-fluid, percolated dipolar network, and phase separated states. We also compare the phases formed by the mixture in an external field to the phases formed when no field is applied and examine the key differences between the two. Interestingly, we find that the mixture exhibits phase separation behavior at lower Peclet number when in an external field than when not in a field. Results from this work aid in our understanding of directed assembly of colloidal particles.

Investigating Crop Yield and Water Quality Benefits of Drainage Water Recycling

Moursi, Hossam Abdelghani Abdelhalim North Carolina State University ProQuest Dissertat 2022 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Drainage water recycling (DWR) has been proposed to improve crop production by providing supplemental irrigation during the dry periods of growing season, and improve water quality by reducing downstream nutrient and sediment losses. Limited number of studies were conducted to investigate the performance of DWR. The objectives of this study were to: 1) experimentally evaluate the effect of DWR on reducing the export of nitrogen (N), phosphorous (P), and sediment loadings from agricultural fields to downstream surface water bodies; 2) experimentally quantify the effect of DWR on corn and soybean yields during 4 growing seasons with varying weather conditions; 3) enhance DRAINMOD model to simulate the hydrology and crop yield of DWR systems. Water quality and hydrology data were collected for two years (May 2019-April 2021) at a research site in eastern North Carolina. On average, the DWR reservoir retained 14% of received inflow. The reservoir significantly reduced nitrate-N(NO3-N), ammonium-N (NH4-N), and total N (TN) concentrations by 53%, 51%, and 40%, respectively. The mass loadings of NO3-N, NH4-N, and TN were also reduced by 59%, 56%, and 47%, respectively. Orthophosphate (OP) concentration was significantly reduced by 46%, while Total P (TP) concentration reduction was not statistically significant. The mass loadings of OP and TP were reduced by 52% and 30%, respectively, while particulate P load was not significantly different. Sediment concentration was significantly reduced by 86% and the sediment loading was also reduced by 87%. Two treatments were monitored at the same study site for 4 growing seasons (2018- 2021): DWR and control treatment (CT). The CT treatment was a non-irrigated field that was primarily drained by a surface drainage system. The DWR treatment had a subsurface drainage system that was used to drain the field during the wet periods of the growing season and subirrigated it during dry periods. DWR increased corn yields by 0.39 and 0.90 Mg ha-1 and soybean yields by 0.40 and 0.66 Mg ha-1 . DWR mainly increased crop yield by reducing drought stress during the critical crop growth stages through providing irrigation (5 to 73 mm). In addition, the smart drainage water management system implemented at the DWR treatment helped to store more water in the soil profile and reduce water outflow from the field. The amount of N and P recycled back to the DWR treatment through irrigation was not large enough to recommend reducing fertilizer application rates. DRAINMOD was enhanced to simulate the hydrology and crop yield of DWR systems as affected by weather conditions, soil type, crop rotation, reservoir size, and irrigation and drainage management. The expanded model; named DRAINMOD-DWR, has a new module that conducts a water balance of the storage reservoir and simulates the interaction between the reservoir and the field, irrigated from and/or draining into the reservoir. Three performance metrics were defined based on model predictions to quantify irrigation, crop yield, and water capture benefits of DWR. To demonstrate the new features of the model, DRAINMOD-DWR was applied to a hypothetical DWR system with continuous corn using a 50-year weather record in Eastern North Carolina, U.S.

Confirmation and Control of Glyphosate-, ALS-, and PPO-Resistant Common Ragweed (Ambrosia artemisiifolia) in North Carolina

Schrage, Brandon William North Carolina State University ProQuest Dissertat 2018 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Soybean (Glycine max L.) is the second largest grain and oil-seed crop grown in the United States after corn (Zea mays L.). Its impact in North Carolina has been paramount in the effort to sustain the state's large swine and poultry industry. A. Glyphosate, ALS, and PPO inhibitors are commonly applied POST to control a broad spectrum of broadleaf and grass weeds in soybean. Their importance in tobacco (Nicotiana tabacum L.), sweet potato [Ipomoea batatus (L.) Lam.], cotton (Gossypium hi.

Source Characterization and Vulnerability Assessment of Nitrate Contamination in Groundwater

Ayub, Riyana North Carolina State University ProQuest Dissertat 2022 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

AYUB, RIYANA. Source Characterization and Vulnerability Assessment of Nitrate Contamination in Groundwater. (Under the supervision of Dr. G. Mahinthakumar)Nitrate contamination in groundwater and surface water from agricultural areas has been a major concern in the United States and around the world for several decades. This study investigates various aspects of nitrate contamination in groundwater and surface water from agricultural practices. This dissertation consists of three major parts. First, non-point source characterization of nitrate contamination into groundwater resources under geological uncertainty was carried out. A Bayesian framework using the Markov Chain Monte Carlo approach (MCMC) was developed to estimate the posterior distribution of non-point sources where uncertainties are due to geological formation (i.e., heterogeneous hydraulic conductivity field). This modeling approach was demonstrated for a hypothetical test case based on the surficial aquifer system in Duplin County, North Carolina. Second, model-based regression approaches for source apportionment were developed using the concept of influence zones to account for transport pathways. The methods are demonstrated using pseudo observations of point-level groundwater nitrate concentrations extracted from a previously published Bayesian Maximum Entropy (BME) model for Sampson and Duplin Counties, North Carolina (NC). Vulnerability assessment of groundwater resources due to nitrate leaching from potential sources of contamination is examined through sensitivity-based scenario analysis which is meaningful for planning and implementation of appropriate mitigation measures. Finally, to account for transport pathways in the integrated groundwater- surface water system, a fully integrated model using SWAT and MODFLOW is developed to simulate the nitrate transport in aquifer using MODFLOW’s reactive transport model, RT3D. This integrated model was used to predict nitrate contamination in groundwater and surface water systems under different climatic and anthropogenic stresses. Climate related analyses were conducted for future periods till the end of this century. A Global Climate Model (GCM), CCSM4, with RCP4.5 emission scenario and downscaled by Multivariate Adaptive Constructed Analogs (MACA) was used for this purpose. From the climate model, an increase of 2.5 to 3 ̊C in annual average temperature is projected; whereas a minimal increase in total precipitation is anticipated over the time. For the anthropogenic stresses, point and non-point source loading from animal farming operations are considered. Model simulations indicate that due to the combined climatic and anthropogenic effects, the basin will experience a decrease of 27% in annual average groundwater nitrate concentration and an increase of 4.5% in-stream nitrate loading for the future period. These projections may aid in planning future agricultural activities under changing climate and increased food demands.