Digital Commons Network^™

Gopher Intrusion In Cropping Systems, Kenneth Romero, Paul Cardinalli

Agricultural Education and Communication

The purpose of this project was to determine if no till vs. till on gopher populations was more beneficial. Which is more efficient at controlling gophers and explain the damage they can cause and the diseases they can potentially vector. What are the different options of pest managements that have to be used when dealing with a gopher infestation in a tilled field vs. a no-tilled field.

Weeds, Nitrogen, And Yield: Measuring The Effectiveness Of An Organic No-Till System, David Robb

All Theses

Previous research in the mid-Atlantic and midwestern USA has identified advantages and drawbacks of "organic no-till" vegetable production, but few studies have been conducted in the warmer southeastern region. The purpose of this study was to examine the effects of tillage [no-till (NT) vs. conventional tillage (CT) of a cereal rye/crimson clover cover crop] and three nitrogen fertilization rates on organic tomato (Solanum lycopersicum L.) and summer squash (Cucurbita pepo L.) yield, weed suppression, and soil N dynamics in two years in a soil series in Clemson, SC. Squash yields were similar between tillage treatments in both years. NT tomato …

Synthesis And Characterization Of Neo-Confused Porphyrins And Related Systems, Arwa Salem Almejbel

Theses and Dissertations

Carbaporphyrins have been the focus of many studies, and a wide variety of related carbaporphyrinoid systems have been reported. N-confused porphyrins are a class of carbaporphyrins where one pyrrole unit has been inverted. In this work, a newly discovered family of porphyrin isomers where one of the pyrrolic subunits is connected to the meso-bridges in a 1,3-fashion, called neo-confused porphyrins, has been investigated.

Reaction of pyrrole-3-carbaldehydes with acetoxymethylpyrroles and NaH in DMF gave neo-confused dipyrrylmethane dialdehydes. The resulting dialdehydes underwent an acid catalyzed condensation with a dipyrrylmethane to give neo-confused phlorins, and following oxidation with FeCl3 afforded new neo-confused porphyrins. …

Minimizing Sheet Resistance Of Organic Photovoltaic Cell Top Contact Electrode Layer: Silver Nanowire Concentration Vs. Conductive Polymer Doping Concentration, Caitlyn Cook

Materials Engineering

The top contact electrode layers of nine organic photovoltaic cells were prepared with two varying factors: three Silver nanowire (AgNW) densities deposited on a conductive polymer doped with three concentrations. Silver’s low sheet resistance of 20-Ω/sq is hypothesized to lower the sheet resistance of the anode layer and thus enhance the overall efficiency of the cell. Four-point probe measurements indicated that increasing AgNW density in the top contact electrode layer of an organic photovoltaic cell significantly reduces sheet resistance from 52.2k-Ω/sq to 18.0 Ω/sq. Although an increase in doping concentration of the conductive polymer reduced sheet resistance in low AgNW …

Economic Assessment Of Organic, Eco-Friendly, And Conventional Peach Production Methods In Northern Utah, Trevor D. Knudsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Fruit producers in Northern Utah face several challenges to their production, urbanization, decreased availability of agricultural land, and competition from domestic producers and imports. As consumers are willing to pay premiums for foods differentiated by production method, such as eco-friendly and organic, conversion to these methods may increase the profitability of fruit growing operations.

This study found that consumers in Northern Utah are willing to pay a premium for peaches grown using organic and eco-friendly production practices over conventionally grown peaches. The study also found that of the three methods of peach production examined (conventional, eco-friendly, and organic), organic had …

Thermal Fluctuations Tunneling In Doped Conjugated Polymers, Troy C. Stedman

USF Tampa Graduate Theses and Dissertations

The possibility of using conducting polymers as organic alternatives to widely used inorganic materials for thermoelectric (TE) applications has received much attention in the past few decades. Since conducting polymers are generally inefficient compared to inorganic TE materials, research into their underlying transport mechanisms is required to improve their efficiency. We use a model based on the effects of local thermal fluctuations to characterize the transport in conducting polymer composites. With this model, full linear responses for the current and electronic heat current are obtained. From these responses, the local temperature dependent conductivity, electronic contribution to the thermal conductivity, and …

Exchange Mechanisms In Macroscopic Ordered Organic Magnetic Semiconductors, Naveen Rawat

Graduate College Dissertations and Theses

Small molecule organic semiconductors such as phthalocyanines and their derivatives represent a very interesting alternative to inorganic semiconductor materials for the development of flexible electronic devices such as organic thin field effect transistors, organic Light Emitting Diodes and photo-voltaic cells. Phthalocyanine molecules can easily accommodate a variety of metal atoms as well in the central core of the molecule, resulting in wide range of magnetic properties. Exploration of optical properties of organic crystalline semiconductors thin films is challenging due to sub-micron grain sizes and the presence of numerous structural defects, disorder and grain boundaries. However, this can be overcome by …

Effects Of Organic And Inorganic Selenium Supplementation During Late Gestation And Early Lactation On Beef Cow-Calf Performance, Christopher Robert Muegge

Open Access Theses

Angus x Simmental cows (n = 48, BW = 594 kg, BCS = 5.26, Age = 2.7), pregnant with male fetuses, were used to determine the effect selenium (Se) source during the last 80 d of gestation and first 108 d of lactation on progeny feedlot performance. At 203 d in gestation, cows were blocked by body weight, age, breed composition, and calf sire, and allotted to 1 of 3 treatments: no Se, inorganic Se, or organic Se. Maternal diets were formulated to contain 10.4% CP and 0.90 Mcal/kg NEg during gestation and 12.1% CP and 1.01 Mcal/kg NEg during …

Photogenerated O-Azaxylylenes: Mechanistic Studies And Synthetic Applications, William Cole Cronk

Electronic Theses and Dissertations

This research sets out to build upon excited state o-azaxylylene cycloaddition. The mechanism behind the excitation and cycloaddition process of photogenerated o-azaxylylenes was determined experimentally. Time-correlated single-photon counting, steady-state spectroscopy, triplet quenching experiments, and quantum yield studies provided evidence suggesting that excited state intramolecular proton transfer is followed by intersystem crossing and stepwise addition to the tethered unsaturated pendant.

In keeping with the principles of diversity oriented synthesis, a modular approach was taken to gain access to a diverse array of N,O,S-Polyheterocycles which were modified postphotochemically via Suzuki coupling to yield fused biaryls. Cycloaddition products, outfitted with halogens …

Retail Distribution Within The New York City Organic Cacao Market, Omari Nekoro Williams

Walden Dissertations and Doctoral Studies

The purpose of this multiple case study was to explore strategies small physical commodities firm owners need to establish a distribution channel within the commodities market to enhance profits. The general business problem was that importing physical commodities from emerging markets was not profitable. The specific business problem was some small physical wholesale commodities firm managers lacked strategies to establish distribution channels for imported commodities. The information presented in this study is important to suppliers, manufacturers, distributors, and retailers of organic cacao products to identify strategies to enhance their distribution channels. Disruptive innovation and the theory of constraints grounded the …

Synthesis And Biological Evaluation Of Nitrile-Based Inhibitors Of Cysteine Proteases Caged With Ruthenium Complexes, Rajgopal Sharma

Wayne State University Dissertations

Light activated compounds can be used as tools for understanding and solving numerous biological problems. This dissertation focuses on developing ruthenium-based photocages for caging nitrile-based cysteine protease inhibitors. Four research areas pertaining to this dissertation, i) metals in medicine, ii) photocages in biological applications, iii) photodynamic therapy and iv) cysteine cathepsin proteases were briefly surveyed in the introductory chapter. Next, RuII(bpy)2 group was utilized for synthesizing nitrile-based caged CTSK and CTSB inhibitors. Light activated release of inhibitors, followed by toxicity and stability data were studied. Cathepsin enzyme activity inhibition in 2D and 3D assays were established. This work showcased the …

Student Perceptions Of Organic Food In Relation To Health, Environment And Pricing, Stacey Paterson

Theses and Dissertations--Nutrition and Food Systems

The organic industry is full of opinions and perceptions, which influence consumer purchasing decisions. A convenience sample of 69 college students between the ages of 19-23 registered in a basic food preparation class participated in this study. A sensory analysis of organic and conventional fruits, vegetables, meat and poultry, eggs and dairy measuring categorical taste differences between the two types of food. Student perceptions of organic foods in relation to health, environment and pricing and the likelihood of purchase were also studied. The influence of Diet and Well-being on organic purchases predominantly mattered somewhat to students, while price mattered completely. …

Mechanical Exclusion And Biological Control Strategies For The Invasive Brown Marmorated Stink Bug, Halyomorpha Halys (Hemiptera: Pentatomidae), Rachelyn Dobson

Theses and Dissertations--Entomology

The brown marmorated stink bug (Halyomorpha halys) is an invasive, agriculturally destructive pest present in most of the United States. Because organic farmers have few effective control options to combat this pest, three potential control options were investigated. Screens of different mesh sizes (0.42cm, 0.32cm, and 0.10cm) that covered vegetable crops were evaluated for their ability to exclude H. halys, allow the entry of beneficial insects, and protect the crop from various types of damage. H. halys and native stink bug egg masses were placed in an organic field and evidence of predation and parasitism from native …

The Production Of Marketable Vegetable Transplants Using Sustainable Locally Sourced Soilless Media Amendments, Amber Dawn Parker

LSU Master's Theses

Public demand for sustainable local and organic food products has led these systems to become one of the fastest growing sectors in the agricultural food market. Consumers are willing to pay a premium for food produced using organic or sustainable practices. Local and small-scale farmers are striving to develop sustainable and in some cases USDA certified organic systems in production of vegetables and fruit. Warm season crops are commonly produced using transplants. Evaluation of nutrient availability is needed for the use of readily available local waste-streams byproducts, such as manures and composts, for amendments or fertilizers in order to manage …

(Re)Localizing Finland’S Foodshed: Grassroots Movements In Food Distribution And Urban Agriculture, Sophia E. Albov

Graduate Student Theses, Dissertations, & Professional Papers

Finland’s agricultural landscape and food production systems have deep societal roots and intimate connections to the Finnish cultural identity. The thesis explores this cultural heritage through an examination of grassroots food distribution networks rapidly diffusing across Finland and an examination of urban agricultural practices in the capital city of Helsinki. This thesis aims to address the following questions: (1) What is the role of grassroots food distribution networks in Finland, and to what extent are they creating alternative farmer-consumer linkages that support eating local? (2) How is urban agriculture structured and organized in Helsinki and within the broader context of …

Aggro Duality, Michael B. Lesh

Electronic Theses and Dissertations

Aggro Duality features sculptures inspired by skateboarding and custom–automobile cultures. This body of work is inspired by the manufacturing process, physicality of materials, individual aesthetic, and attention to craft. Each sculpture in Aggro Duality is created through intensive construction techniques that aim to modify materials into a unified form; which indicate a combination, a duality of mechanical and organic coexistence. Within the skateboarding and custom/automobile cultures there is an aggressive attitude that pushes individuals above and beyond boundaries of traditional standards, meaning, and styles. These cultures intend to create products that are dramatic, personalized, and stand-out from the norm. This …

Investigating The Synthesis Of Heterocycles Via Gold Catalyzed Cyclizations And Cyclo-Dehydrating Reactions, Katherine L. Childers

Undergraduate Honors Thesis Projects

The goal of this project was to study novel synthetic procedures for heterocycles. This was achieved through a two-part investigation. In the first part, a variety of conditions for the gold catalyzed cyclization of allenes were studied. This work was focused on the lesser studied intermolecular reactions of allenes. A variety of allenes were synthesized, and then reacted with 1,3-dipoles and a gold catalyst. These reactions were determined to be unsuccessful through the analysis of nuclear magnetic resonance spectroscopy data. In the second part of this study, the synthesis of 1,3,4-oxadiazoles was investigated. Several cited procedures were examined to determine …

The Efficacy And Non-Target Impacts Of An Organic Disease Management System Containing Biostimulants Compared With Two Sulfur-Based Systems On Four Apple Cultivars In Vermont, Ann L. Hazelrigg

Graduate College Dissertations and Theses

Disease management in organic apple orchards in Vermont is focused on controlling diseases with sulfur fungicides. The objective of this two year study was to evaluate the target and non-target effects of an organic disease management system containing agricultural biostimulants compared to two sulfur-based systems on foliar and fruit diseases, pest and beneficial arthropods, tree growth, yield and fruit quality on four cultivars, `Ginger Gold', `Honeycrisp' and `Liberty' and `Zestar!'. Trees were arranged in a complete randomized design of five three-tree replications in a certified organic orchard. The two sulfur-based systems differed in the number of applications; in the third …

An Evaluation Of Vermicompost As A Fast-Acting Nitrogen Amendment To Mitigate Nitrogen Deficiencies In Organic Vegetable Production, Peter Dalton Austin

Graduate College Dissertations and Theses

For sustained production, organic agriculture depends on plant needs being synchronized with the release of nutrients from organic amendments during decomposition within the soil. Because decomposition is strongly dependent on soil moisture and temperature, nutrient needs may not always be met as planned or synchronous with plant need. Unlike conventional agriculture, fast acting amendments are not readily available. Much of the evidence that vermicompost benefits crop production comes from studies on seed germination and production of starts in greenhouses. Yet, there is a dearth of information derived from field studies. Soil, soil and water nitrogen, plant development, and marketable yield …