The main objective of this study is to analyze the effects cotton quality has on hedging and basis movements within the cotton market to help market participants minimize price risk. The effectiveness of using cotton futures in hedging price risk will be determined by calculating optimal hedge ratios by tenderable quality. Hedge ratios will be calculated using simple differences and error correction models (ECM) on overlapping price data, estimated under both generalized least squares (GLS) and maximum likelihood estimation (MLE). An empirical analysis shows that as cotton quality improves, the optimal hedge ratio decreases. ECMs estimated under GLS are found to be most efficient. It is also found that cotton classing data by quality has no significant effect on cotton basis. Farmers and merchandisers can take these results as a framework to better manage price and basis risk in the hedge and speculative scenarios.

Digital light Projection based Additive Manufacturing (AM) enables fabrication of complex three-dimensional (3D) geometries for applications ranging from rapid prototyping jet parts to scaffolds for cell cultures. Despite the ability in producing complex, three-dimensional architectures, the state of art DLP AM systems is limited to a single homogenous photo-polymer and it requires a large volume of resin bath to begin with. Extensible Multi-material Stereolithography (EMSL) is a novel high-resolution projection stereolithography system capable of manufacturing hybrid 3D objects. This system provides new capabilities, allowing more flexible design criteria through the incorporation of multiple feedstock materials throughout the structure. With EMSL manufacturing ability, multi-material programmable negative Poissons ratio honeycomb reentrant structures are realized. Researchers have been studying auxetic structures over decades, the mechanical property control of auxetic structure mainly relies on geometry design in previous studies. Now with the help of EMSL system, other design variables associated with auxetic structures, such as material properties of local structural members, are added into design process. The additional variables are then proved to have significant effects on the material properties of the auxetic structures. The ability to accurately manufacture multi-material digital design will not only allow for novel mechanical and material researches in laboratory, but also extend the additive manufacturing technology to numerous future applications with characteristics such as multiple electrical, electromechanical and biological properties. The design and optimization of EMSL system realizes novel structures have not been producible, therefore it will stimulate new possibilities for future additive manufacturing development. / Master of Science / Since 1970s, stereolithography, one of the most commonly known additive manufacturing techniques nowadays, has been improving the ability we make things. Through the controllable and repeatable photo-polymerization process, stereolithography can manufacture three-dimensional (3D) physical objects with fast speed, high accuracy and highly detailed surface finish. Today, stereolithography is already widely used in various rapid prototyping and manufacturing areas including dental products, jewelry prototypes, structural and tooling components. While latest researches continuously push its resolution to smaller scale or wider areas, this process is still limited to single material manufacturing. To go beyond this manufacturing limitation, this thesis reports an Extensible Multimaterial Stereolithography (EMSL) system. This system takes advantages of the sequential projections from a digital light modulator, combined with several lowcost while efficient mechatronics components to enable printing at least two types of materials with distinct colors or mechanical properties. With the multi-material printing capability from EMSL, novel multi-material 3D auxetic structures, which have only been theoretical concepts, are successfully manufactured and tested. The reliability of EMSL process and properties of the new materials are investigated with experiments and numerical calculations. The system can be further extended to print multiple feedstock materials into one complex architectural assembly. By realizing multi-material manufacturing capability, EMSL has broaden the potential applications of additive manufacturing and it will enable the development of multiple research and application areas including metamaterial, micro-electromechanical systems and bio-medical implants.

The introduction of airbags has not significantly reduced serious thoracic injury for belted occupants in frontal crashes. This thesis has investigated the effectiveness of airbags and the characteristics of residual thoracic organ injury incurred by belted occupants in vehicles equipped with airbags. This study was based on the injury outcome of over 28,000 belted front seat occupants involved in frontal collisions. Data for this analysis was extracted from National Automotive Sampling System / Crashworthiness Data System (NASS/CDS) case years 1993-2007. The use of odds ratios for comparing the effect of airbags on the occurrence of injury has shown that airbags do not significantly increase protection against head and chest injuries. Overall, the lower extremity and the upper extremity were shown to be adversely affected by airbags. The face was the only body region that was shown to benefit from the combination of seat belts and airbags as compared to seat belts alone. An investigation into the characteristics and distributions associated with thoracic organ injuries showed the heart and great vessels are the only thoracic organs that showed a significant reduction in the rate of injury with the inclusion of airbags. In vehicles with airbags, the thoracic organs are injured more frequently than the ribs. When occupants sustain thoracic organ injury, the delta-V of the crash for vehicles with and without airbags is not significantly different. The odds of serious injury to the lungs and spleen are higher for occupants in vehicles with airbags as compared to those in vehicles without airbags. Rib fracture was found to be a poor predictor of moderate to fatal thoracic organ injury. Only 31-61% of thoracic organ injuries occur with an associated rib fracture. / Master of Science

In somatic cells, checkpoint pathways trigger cell cycle arrest in response to unreplicated or damaged DNA by inhibiting the activity of cyclin-dependent kinases (Cdks). In the Xenopus laevis embryo, checkpoints are not operational until the midblastula transition (MBT). Studies in cell-free egg extracts indicate that a threshold concentration of nuclei, which approximates the MBT concentration, is required to elicit a checkpoint. The checkpoint response to unreplicated DNA in the extract prevents transition into mitosis by inhibiting Cdk1/cyclin B, causing an increase in the minimum amount of cyclin B necessary to enter mitosis, termed the cyclin threshold. Once the threshold of cyclin is maintained or exceeded, the system will proceed into mitosis after a lag time. We have investigated the relationship between nuclear concentration and cell cycle regulation in the extract. By precisely regulating the concentration of cyclin B and nuclear content in extract samples, we have found 1) the concentration of nuclei affects cyclin B thresholds and lag time of entry into mitosis, 2) elevated cyclin thresholds caused by DNA replication blocks are further increased by increasing the concentration of nuclei, and 3) double-stranded DNA breaks in the extract system do not affect cyclin thresholds or lag time of entry into mitosis within the range of nuclear concentrations that can be efficiently replicated. This data provides evidence of the importance of the nucleocytoplasmic ratio in normal cell cycle progression and its importance for checkpoint acquisition during early Xenopus laevis development. / Master of Science

The objective of this study was to determine how the key features of bioreactor landfills; increased temperature, moisture and microbial activity, affect the biological stability of the landfill material. In the first part of the study the solubilization and degradation of lignin in paper exposed to these bioreactor landfill conditions are explored. The solubility of the lignin in paper was observed at different temperatures and over 27 weeks at 55°C and the anaerobic bioconversion of office paper, cardboard and Kraft lignin was observed in bench-scale reactors over 8 weeks. As the temperature rose, lignin solubility increased exponentially. With extended thermal treatment, the dissolution of lignin continues at a constant rate. This rate increases 15 times for paper and 1.5 times for cardboard in the presence of rumen inoculum compared to un-inoculated systems. At around 6 weeks the inter-monomeric linkages between the solubilized lignin molecules began breaking down, releasing monomers. In cardboard and Kraft lignin, a significant amount of the monomers mineralize to CO₂ and CH₄ during this time period. The results indicate that small, but significant rates of lignin solubilization and anaerobic lignin degradation are likely to occur in bioreactor landfills due to both higher temperature and microbial activity. In the second part of the study, field data from the Outer Loop Recycling and Disposal Facility in Louisville, Kentucky was evaluated to determine the effectiveness of an anaerobic-aerobic landfill bioreactor (AALB) vs. the control landfill that is managed as a traditional landfill. Moisture, temperature, elevation and the amount of time the MSW has spent in the landfills (age) were measured and compared to determine the factors that affect the biological stability of the landfill. The results showed that the MSW in the AALB is more biologically stable than the MSW in the control landfill, indicating that they are more degraded. Additionally, elevation or location of the MSW was the key factor in determining the extent of MSW stability within the AALB and temperature is the key factor in determining the biological stability of the MSW in the control landfill. Higher temperatures correlated with a more biologically stable waste. The cellulose to lignin ratio (C/L ratio) and biochemical methane potential (BMP) were the main biological stability parameters used. / Master of Science

Passenger car equivalents (PCEs) are used in highway capacity analysis to convert a mixed vehicle flow into an equivalent passenger car flow. This calculation is relevant to capacity and level of service determination, lane requirements, and determining the effect of traffic on highway operations. The most recent Highway Capacity Manual 2000 reports PCEs for basic freeway segments according to percent and length of grade and proportion of heavy vehicles. Heavy vehicles are considered to be either of two categories: trucks and buses or RVs. For trucks and buses, PCEs are reported for a typical truck with a weight to power ratio between 76.1 and 90.4 kg/kW (125 and 150 lb/hp). The weight to power ratio is an indicator of vehicle performance. Recent development of vehicle dynamics models make it possible to define PCEs for trucks with a wider variety of weight to power ratios. PCEs were calculated from the relative impact of trucks on traffic density using the simulation model INTEGRATION. The scope of this research was to evaluate PCEs for basic freeway segments for trucks with a broader range of weight to power ratios. Such results should make freeway capacity analysis more accurate for mixed vehicle flow with a non-typical truck population. In addition, the effect of high proportion of trucks, pavement type and condition, truck aerodynamic treatment, number of freeway lanes, truck speed limit, and level of congestion was considered. The calculation of PCEs for multiple truck weight to power ratio populations was not found to be different from single truck weight to power ratio populations. The PCE values were tabulated in a compatible format to that used in the Highway Capacity Manual 2000. / Master of Science

The net present replacement value of all publicly and privately owned potable water pipes in the U.S. is on the order of $2.4 trillion dollars, and costs associated with deteriorating iron pipes is billions of dollars per year. Problems arising from iron corrosion include reduced lifetime of the material, scale buildup and energy loss, nonuniform corrosion and leaks, catastrophic failure, "red water," disinfectant loss and bacterial re-growth. Iron corrosion is a very complicated process and is affected by many factors. This research focused on the effect of disinfectant type, sulfate/chloride ratios, nitrate concentration, and magnesium hardness on iron corrosion. For the waters tested, chlorine better controlled red water and microbial activity in the bulk solution than chloramine. Changes in the sulfate/chloride ratio did not have a large effect on iron corrosion. High levels of nitrate increased the rate of chlorine decay as a result of free ammonia formation, and also increased the release of iron. Increased magnesium and zinc decreased the red water caused by high silicate. Microbiological activity is important in iron corrosion, and control of re-growth in water distribution systems is a major challenge for water utilities. A separate study examined the inter-relationship between iron corrosion and bacterial re-growth, with a special focus on the potential of iron pipe to serve as a source of phosphorus. Under some circumstances corroding iron and steel may serve as a source for all macronutrients necessary for bacterial re-growth including fixed carbon, fixed nitrogen and phosphorus. Conceptual models and experimental data illustrate that levels of phosphorus released from corroding iron are significant relative to that necessary to sustain high levels of biofilm bacteria. Consequently, it may be more difficult to limit re-growth on iron surfaces by limiting phosphorus in the bulk water. / Master of Science

Yes / In this paper, single-element and MIMO microstrip antenna with two pairs of unequal slits is proposed as a circularly polarized antenna with negligible back radiation for 5G mid-band handsets. The unequal pairs of slits are engraved on the antenna patch to guarantee the presence of the circular polarization (CP). The proximity-coupled feeding technique is used to excite the proposed microstrip antenna in order to provide larger antenna -10 dB bandwidth which approaches 10.8% (3.48-3.87 GHz). A novel analysis technique is proposed in this paper that demonstrates the 3D axial ratio pattern in order to generate CP in the broadside direction without affecting the structure of the ground plane which ensures weak back radiation. The 3 dB axial ratio bandwidth (ARBW) is found to be equal to 4.1% extended along the range (3.58-3.73 GHz). To make the design more compatible with the 5G mid-band handsets, the 2 × 2 MIMO structure of the proposed antenna with reduced mutual coupling (less than -20 dB) is also presented in this work. The simulation and measured results are in good agreement, and both verify the CP characteristics and the weak back radiation of the proposed antenna. / This paper is partially funded by British Council “2019 UK-China-BRI Countries Partnership Initiative Programme” with project titled “Adapting to Industry 4.0 Oriented International Education and Research Collaboration”.

Yes / The content validity ratio originally proposed by Lawshe is widely used to quantify content validity and yet methods used to calculate the original critical values were never reported. Methods for original calculation of critical values are suggested along with tables of exact binomial probabilities.

The poultry industry is efficient in its production and advancements due to many factors, especially its embrace of innovation. This thesis explores two areas within poultry nutrition that are vital to continue poultry production’s correct trajectory in providing the world with a sustainable, cost effective, nutritionally rich nutrient source. First, the efficacy of a new generation exogenous carbohydrase enzyme within reduced nutrient corn, soybean meal, and corn distillers dried grains with solubles (cDDGS)-based diets is explored using male broilers in a 42 d grow out including processing (Chapter II). Next, feed conversion ratio (FCR), a valuable metric used across production and research settings to assess the bird’s efficiency of converting feed nutrients into muscle gained, will be assessed using variations of the calculation in different research scenarios (Chapter III). Data produced from these studies have practical applications to help optimize poultry nutrition and improve production efficiency in a rapidly evolving landscape.