140816 research outputs found
Sort by
Evaluating Metamitron Efficacy for Glyphosate-resistant Palmer Amaranth (\u3cem\u3eAmaranthus palmeri\u3c/em\u3e) Management in Sugarbeet Across the Central High Plains
No full textHerbicide-resistant (HR) Palmer amaranth (Amaranthus palmeri S. Watson) is regarded as one of the most prominent weeds within sugarbeet fields across the Central High Plains, with limited chemical control options. Although a few herbicides are available, their use is restrictive due to crop injury concerns and can only be applied at or after the 2–4 true leaf (TL) growth stage, which will provide no control for already emerged weeds. However, Palmer amaranth often emerges between sugarbeet planting and the 2 TL sugarbeet growth stage. Consequently, as of 2023, there were no herbicide options to control Palmer amaranth in sugarbeet prior to the 2–4 TL stage, or after Palmer amaranth emerges. Research presented in this thesis focuses on the use of metamitron as a pre-crop emergence (PRE) herbicide in sugarbeet, in relation to Palmer amaranth control and crop safety. Chapter 1 reviews sugarbeet production in the United States, the most common weed species in sugarbeet production systems, the biology and management of Palmer amaranth in sugarbeet, and the available effective herbicide options in the western sugarbeet production region to manage HR-Palmer amaranth. Chapter 2 evaluated high rates of metamitron applied PRE compared to existing herbicide options, and how metamitron may be implemented with other herbicide programs. Season-long weed control of various species and sugarbeet yield were assessed. Chapter 3 is an assessment of the optimal field rate of metamitron applied PRE, alone or in combination with ethofumesate, for control of Palmer amaranth during the first six to ten weeks of the sugarbeet crop. Chapter 4 assesses crop safety of metamitron-based treatment programs at application timings that are not allowed on the herbicide label, simulating situations where a farmer is unable to make a timely application due to weather or field conditions.
Advisor: Nevin C. Lawrenc
The Product of Property Tax: How Property Tax Affects Agricultural Production in Nebraska
No full textThe question of what level of property tax is acceptable has become an increasingly prominent question within agriculture, which is shown by the rise of interest groups and bill introduction in Nebraska. As such, this paper examines how property taxes affect Nebraska\u27s agricultural output. The study employs a quantitative analysis of all Nebraska counties over 21 years from 2000 to 2020. This study hypothesizes that as property tax rates increase, farm outputs will decrease. The study offers a new analysis in an understudied subsection of the agriculture policy literature and points towards a new direction in which the field can improve. The findings support the hypothesis in two of the four crops, corn, and soybeans, which are two of the primary crops produced in Nebraska. With the property tax debate taking center stage in Nebraska’s political climate, these results highlight the concrete impacts that current and future policy decisions have on agriculture within the state.
Advisor: Ross Mille
Experimental Evaluation of Corrosion of Strands and Wires to Estimate Corrosion Rate in Grout and Concrete
No full textPremature failure of prestressed and post-tensioned concrete structures is frequently caused by undetected corrosion of prestressing steel. Although extensive research has addressed corrosion rates in conventionally reinforced concrete, the interpretation of non-destructive parameters, such as half-cell potential (HCP) and concrete/grout resistivity, for estimating corrosion rates in prestressing steel are not adequately investigated.
This research experimentally evaluates chloride-induced corrosion of prestressing steels to establish material-specific relationships between in-situ measurable parameters and corrosion rate. Thirty-six macrocell specimens incorporating plain wires, indented wires, and seven-wire strands in structural concrete and commercial post-tensioning grout- half with pre-formed surface cracks, were subjected to accelerated cyclic wetting with 3 % NaCl solution and drying. Macrocell current, HCP, and matrix resistivity were monitored continuously, while post-exposure forensic examination quantified localized damage and validated the non-destructive measurements.
Key findings reveal that strand geometry and grout microstructure accelerate corrosion. Microcell corrosion accounts for the majority of material loss, indicating that macrocell current measurement alone is unconservative. Corrosion propagation initiated abruptly at around 10 μm/year, followed by exponential acceleration under cyclic moisture exposure contradicting traditional models that assume decelerating rates due to drying of concrete. Robust empirical relationships between corrosion rate and matrix resistivity have been developed that physically capture the transition from ohmic/anodic to diffusion/cathodic control mechanism enabling quantitative corrosion rate estimation from routine field resistivity measurements. In contrast, HCP exhibited only qualitative correlation with corrosion rate, but material-specific thresholds were established: high corrosion (\u3e10 μm/year) corresponds to HCP \u3c −450 mV/CSE and resistivity \u3c 600 k·cm in grout versus \u3c −250 mV/CSE and \u3c 450 kΩ·cm in concrete. A linear correlation between HCP and material resistivity has been developed to further aid engineers in in situ measurements and interpretation.
The study provides experimentally validated, prestressing steel-specific corrosion rate models and interpretation protocols. Practical field guidelines and risk classification tables for resistivity and HCP tailored to strands in grout and concrete are proposed, which are expected to significantly improve the reliability of condition assessment in prestressed and post-tensioned structures, enabling proactive maintenance before catastrophic failure.
Advisor: Jiong H
The Partsongs of Samuel Coleridge-Taylor
No full textThis document examines the complete set of thirteen partsongs by Samuel Coleridge-Taylor (1875-1912) a body of choral works underrepresented in both scholarship and performance. Before the twentieth century, English partsongs had already developed a rich lineage through composers such as Charles Hubert Hastings Parry, Charles Villiers Stanford, Edward Elgar, and Charles Wood. Around 1900, the genre flourished further in the works of Gustav Holst, Ralph Vaughan Williams, Gerald Finzi, and Herbert Howells, whose partsongs were published by Novello & Co. and featured in The Musical Times. Within this broader context, Coleridge-Taylor’s contributions stand apart: his partsongs reveal a distinctive harmonic language and expressive depth that have received comparatively little scholarly attention.
Although Coleridge-Taylor’s large-scale choral and orchestral compositions have gained increasing recognition, his partsongs—setting texts by Christina Rossetti, Thomas Hood, Matthew Arnold, and others—demonstrate a refined approach to text setting, harmonic design, and expressive pacing that merits renewed study. Through detailed analysis of melody, harmony, rhythm, texture, and dynamic structure—through the lens of form—this study identifies recurring traits that define Coleridge-Taylor’s choral voice: chromatic yet functionally grounded progressions, expressive use of suspensions and altered chords, frequent descending melodic lines that evoke reflection, and rhythmic flexibility created through duple groupings in compound meter. His sensitivity to poetic imagery is reflected in subtle text painting, dynamic shaping, and cadential pacing that mirror natural cycles of life, death, and renewal.
This document also considers performance impactions, emphasizing balance, tuning, and phrasing strategies that enhance the harmonic and textual clarity. The findings affirm that Coleridge-Taylor’s partsongs are accessible and artistically rewarding for advanced high school, collegiate, community, and professional ensembles. By situating these works within the broader context of late-Romantic and early-twentieth-century British choral traditions, this study contributes to ongoing efforts to restore Coleridge-Taylor’s rightful place in the canon and to encourage their continued study and performance.
Two editorial notes for this document are: 1) the publishing company Novello & Co will be referred to in this manner, per the Grove Music Online article, instead of using the other variations of its name; 2) the formatting of citations in this document follow the Chicago Manual of Style, 17th edition.
Advisor: Peter A. Eklun
USDA Reports on Land Values and County-Level Cash Rent Estimates in Nebraska for 2024
Get PDFSurvey findings from the USDA-National Agricultural Statistics Service (USDA-NASS) estimated that the value of Nebraska farm real estate, which includes all agricultural land and buildings, increased by 6.8% in 2024, to an average of 260 for this annual period (USDA-NASS 2024a). Florida and Tennessee lead the nation with the highest growth rates in farmland market value at 13.4% and 10.7%, with average market values of 5,710 per acre, respectively. Nebraska ranks 13th for the percentage increase in farm real estate compared to other states in 2024
Proximal Remote Sensing: An essential tool for bridging the gap between high resolution ecosystem monitoring and global ecology
No full textGMOs and Public Perception: College Students’ Opinions and Knowledge of Genetic Engineering
No full textGenetically modified organisms (GMOs) can be developed and implemented to address significant global challenges, including nutrient deficiencies, climate change, and crop disease. However, widespread opposition has prevented the success of GMOs. We believe this opposition is strongly connected to a lack of understanding about genetics in general, which has been reflected by previous studies.
In this study, we considered the relationship between GMO support and genetics knowledge by comparing results from a brief quiz and responses to prompts relating to GMOs. Using a survey of college students, we found that support for GMOs and general knowledge of genetics are positively correlated, indicating that misconceptions about GMOs impact public opinion about them. This stresses the need for proper education, enabling individuals to draw reasonable conclusions about the risks and rewards of GMOs. By addressing misinformation and teaching stronger scientific foundations, we can foster constructive conversations about GMOs, empowering the implementation of agricultural biotechnology to offer global solutions
Melittological Notes from Guatemala (Hymenoptera: Anthophila), 2. New Country Records for Apidae (Anthophorini and Centridini) and Halictidae (Augochlorini)
No full textWe report three new country records of bee species (Hymenoptera: Anthophila) from Guatemala: Centris flavifrons Fabricius and Deltoptila costaricensis Friese, both in the family Apidae, and Caenaugochlora costaricensis Friese, in the family Halictidae. We illustrate the species and discuss their present-day distribution. These new data contribute to the growing knowledge on native bee diversity from Central America, especially from Guatemala.
Resumen
Reportamos tres nuevos registros de abejas (Hymenoptera: Anthophila) en Guatemala, Centris flavifrons Fabricius y Deltoptila costaricensis Friese, ambas de la familia Apidae, y Caenaugochlora costaricensis Friese, de la familia Halictidae. Presentamos las especies y discutimos su distribución actual. Estos nuevos datos contribuyen al conocimiento creciente de diversidad de abejas nativas de Centroamérica, especialmente de Guatemala
Annotated Checklist and Distribution of the Jewel Beetles (Coleoptera: Buprestidae) of Idaho
No full textAn annotated checklist of the 102 species of Buprestidae (Coleoptera) known to be present in the state of Idaho is provided, with photographs and detailed distribution maps for each species. The checklist is based on label data from 7,506 museum specimens, 21 observations obtained from iNaturalist.org and Bug-Guide.net, and 63 distribution records from published literature. Buprestis consularis Gory is a new record for Idaho, formerly reported as Buprestis nutalli Kirby, which is not known to occur in the state. Obscure past records of Anthaxia retifera LeConte and Melanophila occidentalis Obenberger published in the literature are regarded as dubious and are not confirmed by actual specimens. These species are therefore excluded from the checklist. Knowltonia calida (Knull) and Chrysobothris caurina Horn are also absent from Idaho, their previously published records based on misidentifications of K. biramosa Fisher and C. leechi Barr, respectively
Navigating Farm Succession Without a Family Heir: Right of First Offer and Right of First Refusal
No full textAs discussed in the previous article, using an option to buy agreement can unintentionally force your heirs to sell property, which may not be your intent. Instead, you might prefer to offer someone the chance to buy only if your heirs choose to sell. These types of arrangements are known as preemptive rights, and they come in two main forms: Right of First Offer and Right of First Refusal. This article explores both in more detail