Scholarship & Research
Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/1
Browse
5 results
Search Results
Item Evaluating the genetic and phenotypic responses of Camelina sativa to heat stress(Montana State University - Bozeman, College of Agriculture, 2023) Smith, Brian Edward; Chairperson, Graduate Committee: Chaofu LuCamelina sativa (L.) Crantz is a low-input oilseed crop with a unique fatty acid profile in its seed oil. Camelina oil can be used in biodiesels, jet fuels, and industrial lubricants. Improving the abiotic stress tolerance of camelina is a crucial step for increasing agronomic viability. Climate change is threatening production of camelina with rising global temperatures and shorter growing seasons. Elucidating the phenotypic and genetic responses to high temperatures is essential for successful breeding of heat tolerant camelina varieties. Three experiments were conducted to understand these responses. Two genotypes, Suneson (MT5) and Pryzeth (MT102) were exposed to a transient 14-day heat stress during the reproductive stage and evaluated for agronomic and seed quality traits along the main stem. Next, a mapping population consisting of 257 recombinant inbred lines (RILs) were grown under the same temperature regimes for 14 days beginning at the onset of the reproductive stage. Finally, reproductive tissues undergoing heat stress from two genotypes with contrasting heat responses, RIL23 and RIL167, were examined with RNA sequencing, and the phenotypes along the main stem were compared. From the phenotype evaluation, both MT5 and MT102 were significantly impacted by heat. Both genotypes experienced reductions in seed and pod size, seed weight, and total oil contents. As reported in other oilseed crops, camelina is negatively affected by heat, characterized primarily by lower yield and reduced oil content. The QTL analysis identified several key gene regions with co-located traits on chromosomes 8, 10, and 12. This demonstrates the ability to identify heat-responsive gene regions via phenotyping along the main stem. The transcriptomes of RILs 23 and 167 contrasted in both sampled tissue types, with RIL23 appearing more responsive to heat. Phenotypic analysis of these genotypes confirmed the transcriptional differences, as RIL23 was more resistant for several traits associated with fertility. These studies provide resources and protocols for future studies that may assist in improving the heat-tolerance of camelina.Item Thermal energy storage with sensible heat in an air-alumina packed bed using axial flow, axial flow with layers and radial flow(Montana State University - Bozeman, College of Engineering, 2020) Al-Azawii, Mohammad Mahdie Saleh; Chairperson, Graduate Committee: Ryan Anderson; Carter Theade, Megan Danczyk, Erick Johnson and Ryan Anderson were co-authors of the article, 'Experimental study on cyclic behavior of thermal energy storage in an air-alumina packed bed' published in the journal 'Journal of energy storage' which is contained within this dissertation.; Carter Theade, Pablo Bueno and Ryan Anderson were co-authors of the article, 'Experimental study of layered thermal energy storage in an air-alumina packed bed using axial pipe injections' in the journal 'Applied energy' which is contained within this dissertation.; Duncan Jacobsen, Pablo Bueno and Ryan Anderson were co-authors of the article, 'Experimental study of thermal behavior during charging in thermal energy storage packed bed using radial pipe' in the journal 'Applied thermal engineering' which is contained within this dissertation.Thermal behavior in a packed bed thermal energy storage (TES) system is studied experimentally. TES systems are a promising solution to integrate renewable energy sources such as solar energy. The performance of such systems can be affected by different variables such as storage material size/type, pressure, temperature, heat transfer fluid (HTF), storage type (sensible/latent heat), and flow rate. Although these variables have been studied in literature, the resulting thermal dispersion and heat losses to the environment have been considered in few studies. This thesis studies the thermal behavior of an air-alumina TES packed bed focusing on dispersion and heat losses to quantify the thermal performance. Reducing their effects can improve the thermocline and thus thermal efficiency. The research efforts in this work quantify these effects and provide two new methods to reduce thermal dispersion and increase exergetic efficiency. Three configurations were considered in the present study. In the first configuration, a traditional packed bed is used focusing on performance for multiple partial cycles. This configuration quantified the thermal performance and served as a basis to compare the results from the other configurations. Dispersion effects were found to accumulate before a steady state was achieved during cycling. In the second and third configurations, novel pipe injection techniques were used to charge/discharge the bed. First, the normal bed is divided into layers via inserting pipes along the bed's axial length, focusing on a full charge-discharge cycle. Results show that exergy efficiency increases with flow rate and number of layers. The thermocline improved and dispersion losses decreased with number of layers. Second, a perforated pipe to facilitate radial flow was inserted at the center of the bed along the axial length to heat the bed. Radial charging shows higher charging efficiency compared to normal axial charging. Pipe injection is a novel method and a promising technique that improves the thermal performance of a lab scale storage bed, especially the layering method. Radial injection warrants more investigation to quantify its performance in thermal cycles.Item An acoustic emission and hygrothermal aging study of fiber reinforced polymer composites(Montana State University - Bozeman, College of Engineering, 2019) Newhouse, Kai Jeffrey; Chairperson, Graduate Committee: David A. MillerFiber reinforced polymer matrix composites are a premier choice for offshore wind turbines and Marine Hydro-Kinetic Devices, which operate in harsh and isolated marine environments. These factors combined with decades long target service life make imperative the understanding of damage mechanisms and the environmental effects thereof. Acoustic emission monitoring is a research technology that uses specialized sensors to detect transient elastic waves in a material which originate from damage sources. Waveform parameters have been correlated with different damage mechanisms in fibrous composites. A diverse set of fiber-matrix combinations configured into a variety of layups totaling more than 30 laminates were mechanically tested in quasi-static uniaxial tension while monitoring acoustic emission. A subset of these materials was aged prior to testing in an artificial marine environment by soaking in a water bath of simulated seawater at 50 degrees Celsius. Various acoustic emission waveform parameters were investigated with respect to expected damage between layups and possible material-based differences. Among the conditioned material set, mechanical changes from moisture absorption shows mixed levels of degradation among different material systems. Moduli were generally unaffected with a few minor decreases. Strengths were reduced by as much as 41%, and failure strains fell as much as 47%. From acoustic emission investigation, good correlation is found between Fast Fourier Transform peak spectral frequency bands and expected damage mechanisms between layups. Material based peak frequency differences are found exclusively in interphase failures (de-bond and fiber pullout). Layup-based correlations in conjunction with elastic wave theory were used to put forth new frequency band ranges associated with damage types.Item Developments in electrically conductive bio-composites for use in additive manufacturing(Montana State University - Bozeman, College of Engineering, 2019) Arroyo, Jesse Whitney; Chairperson, Graduate Committee: Cecily Ryan; Cecily Ryan was a co-author of the article, 'Incorporation of carbon nanofillers tunes mechanical and electrical percolation in PHBV:PLA blends' in the journal 'Polymers' which is contained within this thesis.With the growth of rapid production methods, such as additive manufacturing, petroleum derived plastics are becoming ever more prevalent in consumer homes and landfills. As the industry grows, research into a more circular approach to designing and using materials is critical to maintaining sustainability. Bioplastics such as poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) and poly(lactic acid) (PLA) provide material properties comparable to petroleum derived plastics and are becoming more common in the additive manufacturing field. Biobased fillers, such as bio-derived cellulose, lignin byproducts, and biochar, can be used to modify the thermal, mechanical, and electrical properties of polymer composites. Biochar (BioC), in particular, is of interest for enhancing thermal and electrical conductivities in composites, and can potentially serve as a bio-derived graphitic carbon alternative for certain composite applications. In this work, we investigate a blended biopolymer system: PLA/PHBV, and addition of carbon black (CB), a commonly used functional filler as a comparison for Kraft lignin-derived BioC. We present calculations and experimental results for phase-separation and nanofiller phase affinity in this system, indicating that the CB localizes in the PHBV phase of the immiscible PHBV:PLA blends. The addition of BioC led to a deleterious reaction with the biopolymers, as indicated by blend morphology, differential scanning calorimetry showing significant melting peak reduction for the PLA phase, and a reduction in melt viscosity. For the CB nanofilled composites, electrical conductivity and dynamic mechanical analysis supported the ability to use phase separation in these blends to tune the percolation of mechanical and electrical properties, with a minimum percolation threshold found for the 80:20 blends of 1.6 wt.% CB. At 2% BioC (approximately the percolation threshold for CB), the 80:20 BioC nanocomposites had a resistance of 3.43x10 8 Omega as compared to 2.99x10 8 Omega for the CB, indicating that BioC could potentially perform comparably to CB as a conductive nanofiller if the processing challenges can be overcome. Investigations into alkaline and dealkaline lignin sources have shown that alkaline lignin experiences a significant effect on the thermal stability of PHBV eluding that alternate sources of lignin may provide a solution to the processing challenges mentioned. This work has helped to develop a understanding of the factors that aid in creating sustainable materials sourced from PLA,PHBV, and BioC.Item Extending cool season production of vegetables in the high tunnel: balancing heat and light(Montana State University - Bozeman, College of Agriculture, 2019) Baumbauer, David Alan; Chairperson, Graduate Committee: Mac Burgess; Macdonald H. Burgess was a co-author of the article, 'The Montana high tunnel growers survey - identifying grower practices and concerns' submitted to the journal 'HortTechnology' which is contained within this thesis.; Macdonald H. Burgess was a co-author of the article, 'Row cover influences light transmisson, air and soil temperatures in the high tunnel during Spring and Fall' submitted to the journal 'Journal of agricultural and forest meteorology' which is contained within this thesis.; Macdonald H. Burgess was a co-author of the article, 'Season, sowing date, and row cover influence the production of cool season vegetables in the moveable high tunnel' submitted to the journal 'Canadian journal of plant science' which is contained within this thesis.; Colleen B. Schmidt and Macdonald H. Burgess were co-authors of the article, 'The influence of low daily light integral on the growth of baby kale, lettuce and spinach' submitted to the journal 'HortScience' which is contained within this thesis.Montana high tunnel growers face challenges associated with being at a northern latitude and high elevation. The wide seasonal fluctuation in photosynthetically active radiation coupled with wide diurnal temperature swings produces a dynamic growing environment within the high tunnel. This dissertation is comprised of four studies investigating the management of light and temperature and their influences on high tunnel grown crops. Chapter one is an introduction to high tunnels and production strategies. Chapter two discusses the results of the Montana High Tunnel Growers Survey, in which respondents reported that managing the high tunnel environment was their number one challenge. Two thirds of respondents produced crops during the shoulder seasons of spring and fall, a period of time when the climatic conditions are especially dynamic. Chapter three presents the findings on the influences various types of season extension have on light and temperature levels and the impacts they have on the accumulation of growing degree hours, soil degree hours, and daily light integral. While each layer retains heat, moderating the effect of low night air temperatures, it comes at the cost of lower light energy at the crop level. Heat retention performance of high tunnel plus row cover improves as outside air temperature decreases, maintaining crop level air temperature at -3°C despite an outside air temperature of -22°C. Chapter four presents the results of seeding date and row cover effects on the yield and days to harvest of six cool season crops. Row cover within the high tunnel only improved crop yields when outside air temperatures were well below the historical average. The early seeding date in the fall resulted in higher yields and fewer days to harvest, indicating that the two weeks difference between August 15th and August 30th has a large impact on production. Chapter five reports on the influence of low daily light integral has on the production of kale, lettuce, and spinach. While all three responded to increasing light, lettuce had the largest response with a 200% increase in dry weight when the daily light integral increased from 8 to 14 mol m -2 d -1.