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Articles 1 - 21 of 21
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Properties Of 25cr7ni Stainless Steel Fabricated Through Laser-Powder Bed Fusion., Arulselvan Arumugham Akilan
Properties Of 25cr7ni Stainless Steel Fabricated Through Laser-Powder Bed Fusion., Arulselvan Arumugham Akilan
Electronic Theses and Dissertations
Stainless steel is a low carbon high alloyed system with higher concentrations of Cr& Ni, which impart high corrosion resistance to them. Alloys with approximately 25% Cr & 7% Ni in their chemical composition are commercially referred to as ‘Super Duplex Stainless Steel’. They have a unique phase composition of approximately 50% ferrite & 50% austenite, yielding a robust combination of high mechanical strength & corrosion resistance. They find extensive interest & application in the fields which demand a longer service life under intense mechanical / corrosive environment such as offshore oil rigs & pipelines in nuclear power plants. Traditional …
In-Season Crop Management Effect On Soybean Yield And Grain Quality In Eastern South Dakota, Kelsey Bergman
In-Season Crop Management Effect On Soybean Yield And Grain Quality In Eastern South Dakota, Kelsey Bergman
Electronic Theses and Dissertations
Soybean [Glycine max (L.) Merr.] yield has increased over time by introduction of newer varieties and improved agronomic practices. However, grain protein concentration has been decreasing at the same time. New field studies in 2018 and 2019 investigated inseason crop management practices effect such as use of foliar protection application, fertilizer application, different maturity length or different planting dates on grain yield and grain quality. The studies were established near Brookings, SD and Beresford, SD. In-season treatments were targeting nutrient availability or protecting soybean canopy during the grain filling period. Such treatments included the use of fungicide, insecticide, or supplying …
A Numerical And Experimental Study On Effect Of Composition Of Ar-N2 Shielding Gas On The Weld Bead Profile And Its Prediction For Hot Wire Arc Additive Manufacturing, Niraj Pudasaini
Electronic Theses and Dissertations
Wire arc additive manufacturing is a process of making three-dimensional metal parts in a layer-by-layer approach using a feed wire and electric arc as a heat source. Wire arc additive manufacturing (WAAM) is becoming more popular due to its ability to create complex 3D parts, less build time, high deposition rate, and significant cost savings. Out of the many parameters used in WAAM, one of the important parameters is shielding gas which plays a significant role in material quality, properties, and defects. In this study, a controlled amount of Argon (Ar) and Nitrogen (N2) shielding gases are used …
Improved Estimates Of Tributary Nitrogen Load To Casco Bay, Maine, Whitley J. Gray
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 …
Agronomic And Quality Response Of Hard Red Spring Wheat Genotypes To Management Systems In South Dakota, Jonathan Kleinjan
Agronomic And Quality Response Of Hard Red Spring Wheat Genotypes To Management Systems In South Dakota, Jonathan Kleinjan
Electronic Theses and Dissertations
Intensive cereals management techniques such as multiple fungicide applications and in-season split N applications have been used to successfully improve wheat yields in Europe and in some winter wheat production areas of the USA. However, research on the effects of these management practices and their interaction with genotypes is limited in the hard red spring wheat (HRSW) production areas of the USA. The objectives of this study were to: (i) compare management treatments and (ii) quantify any interaction effects between management and genotype on the agronomic characteristics and relevant flour and dough properties of locally-adapted HRSW genotypes. A randomized complete …
Air-Propelled Organic Fertilizer Grits Can Be Used To Control Weeds And Provide Nitrogen, Michael Carlson
Air-Propelled Organic Fertilizer Grits Can Be Used To Control Weeds And Provide Nitrogen, Michael Carlson
Electronic Theses and Dissertations
Weeds are one of the biggest challenges for organic growers because of the alternative weed control methods. Air-propelled abrasive grit management has been reported to control weed seedlings in corn and soybeans while maintaining yield. This research examined the weed control, corn and soybean yields, nitrogen mineralization, and nitrogen yield responses from grits. The grits used in this research included: Phytaboost Plant Food 7-1-2 (soybean meal), Sustane 8-2-4 and 4-6-4 (turkey litters), and two non-fertilizer grits: Agra Grit (walnut shells) and corn cob meal. Field studies were conducted from 2015 to 2017 in Aurora, SD, Beresford, SD and Morris, MN. …
Propagation And Container Production Of The Amelanchier Spicata Complex, Gregory J. Melcher
Propagation And Container Production Of The Amelanchier Spicata Complex, Gregory J. Melcher
Electronic Theses and Dissertations
Amelanchier is a genus in the Rosaceae containing shrubs and trees indigenous to North America that possess traits valued by the horticulture industry. Amelanchier spicata (dwarf serviceberry), a heterogeneous complex of hybrids indigenous to eastern North America, has agricultural and ornamental merit with notable characteristics. White blossoms emerge in early spring, edible pomes ripen in the summer, and vibrant, orange foliage occurs in the fall. I investigated phenological and physiological factors influencing adventitious rooting of stem cuttings, the effects of nitrogen source on the development of seedlings grown in container culture, and phenotypic variation among seedlings of A. spicata from …
Effects Of Small Intestinal Starch Digestion And Dietary Lipid On Efficiency Of Nitrogen Use In Cattle, Ethan J. Blom
Effects Of Small Intestinal Starch Digestion And Dietary Lipid On Efficiency Of Nitrogen Use In Cattle, Ethan J. Blom
Electronic Theses and Dissertations
The objective of this research was to determine the effects of increases in energy available for gain from increased small intestinal starch digestion (SISD) and dietary lipid source and amount on the efficiency of N use in cattle. Five ruminally, duodenally, and ileally cannulated steers were placed in a 5 × 5 Latin square. Each received duodenal infusion of 1.5 ± 0.08 kg/d raw cornstarch and either 0, 30.9 ± 0.59, 62.4 ± 1.16, or 120.4 ± 3.39 g/d Glu, or 387.9 ± 17.47 g/d casein. Casein increased (P = 0.05) SISD. Similarly, greater duodenal Glu linearly (P = 0.02) …
Cooperation And Punishment In The Arbuscular Mycorrhizal Symbiosis: Implications For Resource Exchange & Biological Market Dynamics, Jerry A. Mensah
Cooperation And Punishment In The Arbuscular Mycorrhizal Symbiosis: Implications For Resource Exchange & Biological Market Dynamics, Jerry A. Mensah
Electronic Theses and Dissertations
The arbuscular mycorrhizal (AM) symbiosis is arguably the world’s most abundant and important mutualism, and brings together the roots of the majority of land plants and AM fungi to great mutual advantage. The AM symbiosis can increase the uptake of nutrients, such as phosphorus (P) and nitrogen (N), and improves the abiotic and biotic stress resistance of the host plant. AM fungi have the potential to act as biofertilizers and bioprotectors in sustainable agriculture. However, despite its significance, the mechanisms that control the resource exchange between both partners in the arbuscular mycorrhizal symbiosis are largely unknown. The main aim of …
Evaluation Of Tillage, Crop Rotation, And Cover Crop Impacts On Corn Nitrogen Requirements In Southeastern South Dakota, Sara Louise Berg
Evaluation Of Tillage, Crop Rotation, And Cover Crop Impacts On Corn Nitrogen Requirements In Southeastern South Dakota, Sara Louise Berg
Electronic Theses and Dissertations
Nitrogen (N) is a vital factor of corn (Zea mays) production. Previous work in South Dakota has shown that there is uncertainty as to whether nitrogen requirements are the same for corn raised under no-till (NT) versus conventional till (CT) production systems. The objective of this study was to evaluate whether N requirements continue to be greater under long-term NT versus CT production systems in southeastern South Dakota, while also considering effects from cover crops and crop rotation. This was a two year study conducted at the SDSU Southeast Research Farm near Beresford, SD; it was superimposed on a long-term …
Childhood Diet And Mobility At Medieval (1240s Ad) Solt-Tetelhegy, Hungary As Reconstructed From Stable Carbon, Nitrogen, And Oxygen Isotope Analysis, Ariana Gugora
Electronic Theses and Dissertations
Between 2005 and 2009, archaeologists excavated more than 100 skeletons from the medieval (1240s AD) Hungarian site of Solt-Tételhegy. Stable carbon and nitrogen isotope analyses were conducted on dental enamel and dentin from 24 individuals to examine their childhood diet. Although previous stable isotopic research has described the diet of medieval European peoples, this is the first such study on a medieval Hungarian population. The enamel ?13C values range from -14.4‰ to -8.6‰, with a mean of -11.1‰, while the dentin ?13C values range from -19.4‰ to -14.9‰, with an average of -17.4‰. These data indicate that C3 plants were …
Development Of Treatment Train Techniques For The Evaluation Of Low Impact Development In Urban Regions, Mike Hardin
Development Of Treatment Train Techniques For The Evaluation Of Low Impact Development In Urban Regions, Mike Hardin
Electronic Theses and Dissertations
Stormwater runoff from urban areas is a major source of pollution to surface water bodies. The discharge of nutrients such as nitrogen and phosphorus is particularly damaging as it results in harmful algal blooms which can limit the beneficial use of a water body. Stormwater best management practices (BMPs) have been developed over the years to help address this issue. While BMPs have been investigated for years, their use has been somewhat limited due to the fact that much of the data collected is for specific applications, in specific regions, and it is unknown how these systems will perform in …
Microstructure And Chemistry Evaluation Of Direct Metal Laser Sintered 15-5 Ph Stainless Steel, Kevin Coffy
Microstructure And Chemistry Evaluation Of Direct Metal Laser Sintered 15-5 Ph Stainless Steel, Kevin Coffy
Electronic Theses and Dissertations
15-5PH stainless steel is an important alloy in the aerospace, chemical, and nuclear industries for its high strength and corrosion resistance at high temperature. Thus, this material is a good candidate for processing development in the direct metal laser sintering (DMLS) branch of additive manufacturing. The chemistry and microstructure of this alloy processed via DMLS was compared to its conventionally cast counterpart through various heat treatments as part of a characterization effort. The investigation utilized optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-Ray diffractometry (XRD), energy dispersive X-Ray spectroscopy (EDS) and glow discharge atomic emission spectrometry (GDS) …
Migratory Connectivity And Carry-Over Effects In Northwest Atlantic Loggerhead Turtles (Caretta Caretta, L.), Simona Ceriani
Migratory Connectivity And Carry-Over Effects In Northwest Atlantic Loggerhead Turtles (Caretta Caretta, L.), Simona Ceriani
Electronic Theses and Dissertations
Migration is a widespread and complex phenomenon in nature that has fascinated humans for centuries. Connectivity among populations influences their demographics, genetic structure and response to environmental change. Here, I used the loggerhead turtle (Caretta caretta, L.) as a study organism to address questions related to migratory connectivity and carry-over effects using satellite telemetry, stable isotope analysis and GIS interpolation methods. Telemetry identified foraging areas previously overlooked for loggerheads nesting in Florida. Next, I validated and evaluated the efficacy of intrinsic markers as a complementary and low cost tool to assign loggerhead foraging regions in the Northwest Atlantic Ocean (NWA), …
Landscaping Perceptions And Behaviors: Socio-Ecological Drivers Of Nitrogen In The Residential Landscape, Leesa Souto
Landscaping Perceptions And Behaviors: Socio-Ecological Drivers Of Nitrogen In The Residential Landscape, Leesa Souto
Electronic Theses and Dissertations
Driven by individual influences such as beliefs, attitudes, personal norms, and abilities, as well as by social influences like community norms, mandates, and the market, suburban homeowners are motivated to select and maintain a turf grass landscape. In many areas of Florida, effective suburban lawn maintenance requires regular inputs of nitrogenous fertilizer, some of which is lost to the environment, contributing to water quality degradation and ecosystem dysfunction. Reducing nitrogen inputs to aquatic systems requires a better understanding of the links between residential landscape management and the potential for fertilizer loss. This dissertation examines the linkages between the human behaviors …
A Proposed Methodology For Predicting The Carbon And Nitrogen Stable Isotope Measures Of K'Inich Yax K'Uk Mo', Copan Dynastic Founder, Keith Edwards
A Proposed Methodology For Predicting The Carbon And Nitrogen Stable Isotope Measures Of K'Inich Yax K'Uk Mo', Copan Dynastic Founder, Keith Edwards
Electronic Theses and Dissertations
The purpose of this thesis is to show that stable isotope analysis can be used to predict K’inich Yax K’uk Mo’s stable isotope measures based on Stuart’s (2007) hypothesis that K’inich Yax K’uk Mo’, the dynastic founder of the Copan royal lineage, was a Caracol lord. There is significant and convincing evidence that K’inich Yak K’uk Mo’ had a non-Copanec origin. Stable isotope analysis is a tested and reliable method for detailing diets and migratory paths of ancient humans and this theory is applied as a predictor of the stable isotope measures of K’inich Yax K’uk Mo’, if he did …
An Investigation Of The Role Of Aquatic Plants In The Cycling Of Phosphorus And Nitrogen In Murphy's Bottom Lake, Armstrong County, Pa, Melanie Ann Mathews
An Investigation Of The Role Of Aquatic Plants In The Cycling Of Phosphorus And Nitrogen In Murphy's Bottom Lake, Armstrong County, Pa, Melanie Ann Mathews
Electronic Theses and Dissertations
The objectives established for the Murphy's Bottom Ecological Project are to obtain baseline biological inventories and establish a Master Plan for reclamation of the 100 acre site located in Armstrong County, Pennsylvania. Reclamation plans include connecting the 20+ acre Lake, formed by sand and gravel removal, to the Allegheny River to form a backwater wetlands. This study produced a macrophyte species list, mapped the macrophyte community and determined water and plant phosphorus concentrations and water nitrogen concentrations. Replicable laboratory methods for the analysis of these nutrient concentrations were adapted from established molybdenum blue, Nitrate Electrode and HACH Cadmium Reduction Methods. …
Pilot Study Of Nutrient Loading In A Wet Detention Lake, Eric C. Gurr
Pilot Study Of Nutrient Loading In A Wet Detention Lake, Eric C. Gurr
Electronic Theses and Dissertations
Florida is surrounded by water, and its many internal lakes and rivers have long been recognized for their excellent fishing and boating. This notoriety draws land developers to the lake shores to establish residential and commercial infrastructure. This land development brings with it flood plain alteration, water level stabilization, and increased nutrients which cause adverse impacts to our lakes. In response, the United States Environmental Protection Agency (EPA) passed the Federal Clean Water Act (CWA) in 1972 which set the framework for the water quality standards for the entire United States. As a result of the CWA many point sources …
In-Situ Ammonia Removal Of Leachate From Bioreactor Landfills, Nicole Berge
In-Situ Ammonia Removal Of Leachate From Bioreactor Landfills, Nicole Berge
Electronic Theses and Dissertations
A new and promising trend in solid waste management is to operate the landfill as a bioreactor. Bioreactor landfills are controlled systems in which moisture addition and/or air injection are used as enhancements to create a solid waste environment capable of actively degrading the biodegradable organic fraction of the waste. Although there are many advantages associated with bioreactor landfills, some challenges remain. One such challenge is the ammonia-nitrogen concentration found in the leachate. The concentrations of ammonia-nitrogen tend to increase beyond concentrations found in leachate from conventional landfills because recirculating leachate increases the rate of ammonification and results in accumulation …
Stormwater Irrigation Of Saint Augustine Grass: Nitrogen Balance And Evapotranspiration, Ewoud Hulstein
Stormwater Irrigation Of Saint Augustine Grass: Nitrogen Balance And Evapotranspiration, Ewoud Hulstein
Electronic Theses and Dissertations
A change in surface condition of a watershed, which is usually caused by development, can have measured effects on the naturally occurring hydrologic cycle and nitrogen cycle. This could result in environmental problems, such as reduced springflow and eutrophication. In an effort to address these issues, a combination of best management practices (BMPs) can be adhered to. The practice of using excess stormwater as a source for irrigation is proposed as a BMP for the minimization of impacts by development to the hydrologic and nitrogen cycles. To study the proposed BMP, a field experiment was installed in an outdoor location …
Simulation Of Structure, Dynamics And Electron Diffraction Patterns Of Heterogeneous Clusters Armn2N, W. H. Jinasena
Simulation Of Structure, Dynamics And Electron Diffraction Patterns Of Heterogeneous Clusters Armn2N, W. H. Jinasena
Electronic Theses and Dissertations
The nitrogen-argon system provides a useful paradigm for studying segregation and mixing behavior in heterogeneous clusters. Using three realistic pair potentials corresponding to argon-argon, nitrogen-nitrogen and argon-nitrogen interactions, the structures and thermodynamics of Arm(N2)n, clusters are investigated. Comparison of these results to previous simulation results on neat argon and nitrogen clusters is made. The initial focus of the study is the series of thirteen particle clusters of Arm(N2)13-m (0 ≤ m ≤ 13); molecular dynamics in the microcanonical ensemble is the principle simulation tool. The icosahedral nitrogen-argon clusters …