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Biomass Gasification TEA v1.0
No full textThis spreadsheet is a techno-economic analysis model that estimates the minimum selling price of hydrogen (MSPH) for a biomass gasification facility, using ratio factors to estimate operating and maintenance costs (OSBL)and user-selected, location-specific assumptions. Users configure scenarios using drop-down menus and editable input cells. The model then generates MSPH results on the Output tab. Additionally, it calculates the carbon intensity of the hydrogen pathway and allows users to optionally account for incentives and carbon capture and storage configurations within each scenario
NOVEL EUTECTIC ELECTROLYTES AND ELECTROCATALYSTS SEPARATORS FOR LITHIUM SULFUR AND LITHIUM SELENIUM DISULFIDE BATTERIES
Full text linkLithium-Sulfur (LSBs) batteries and Lithium Selenium disulfide (Li-SeS2) have been intensively studied as one of the most cost effective, environmentally benign, and high energy density energy storage systems for various applications, such as electric vehicles. However, like many emerging energy storage systems, both LSBs and Li-SeS2 batteries suffer from similar challenges such as poor rate capacity retention, short cycle life, and thermal/chemical degradation. These challenges are mainly caused by parasitic reactions relating to (i) dissolution/diffusion of active lithium polysulfide or polyselenide species known as the “shuttle effect” or (ii) decomposition of flammable ether-based solvents species forming a unstable irreversible passivation layer on the lithium metal anode reducing LSBs and Li-SeS2 electrochemical cycling performance. To address these two main issues, many efforts have been devoted towards the development of chemically/thermal stable nonflammable liquid electrolytes or designing functional layered separators to reduce parasitic reactions within both LSBs and Li-SeS2 batteries.This dissertation describes improved rate and prolonged electrochemical cycling performance pertaining to novel nonflammable sulfonamide deep eutectic solvent (DES) withthe addition of fluorinated ether diluent (TTE) within Li-SeS2 battery. Under extreme thermal conditions (0oC to 60oC), we determined that increased concentration of TTE diluent within DES electrolyte maintained thermal stability and improved ionic conductivity (~10-3 S cm-1). Implementing experimental Raman spectroscopy and theoretical molecular dynamic (MD) simulations, the introduction of TTE diluent within DES electrolyte resulted in small aggregation of TFSI- anion in bidentate coordination with multiple Li+ ions. The study-determined DES-4TTE concentration resulted in optimal localized aggregate bidentate TFSI-Li+ ion coordination, improved overall bulk lithium-ion transport, and promoted uniform SEI deposition of LiF on lithium metal anode interface after Li-SeS2 cycling. In conjunction, Li-SeS2 cyclic voltammetry (CV) under various scan rate pertaining to DES-TTE electrolytes demonstrated overall increase in Li+ diffusion coefficient associated with insoluble/soluble lithium polysulfide/polyselenide redox kinetic reactions. We demonstrated that Li-SeS2 utilizing DES-4TTE electrolyte was able to retain specific capacity at high C-rate conditions; when compared to LSBs, this wasdetermined by enhanced Li+ diffusion coefficient analysis of redox Li-SeS2 CV profiles.Benefiting from tunable porous structure of metal-organic frameworks (MOFs), via carbonization of bimetallic nickel-based Ni-M-MOF-74 (M= Fe, Cu, Zn) nanotemplate, wedesigned novel electrocatalyst nickel-based bimetallic alloy nitrogen doped carbon Ni-M-N-C (M=Fe, Cu, Zn) nanocomposite interlayered functional separator for LSBs. While comparing various bimetallic Ni-M-N-C (M = Cu, Fe, Zn) nanocomposites, Ni-Zn-N-C carbonized at 800oC obtained optimal carbon substrate surface defects, micro/mesoporous structure, and uniform distribution of isolated bimetallic Ni3.68 Zn0.32 moieties corresponding to enhanced lithium polysulfide electrocatalyst activity. Implementing LSBs (CV) under various scan rate, Ni-Zn-N-C had enhanced Li+ diffusion coefficient associated with kinetic oxidation/reduction of insoluble Li2S into Li2Sx (4 < x < 8) resulting in improved LSBs rate cycling retention capabilities and prolonged LSBs cycling under high current conditions.This work provides new strategies for the development of high-performance nonflammable lithium-ion electrolytes capable of maintaining thermal/chemical stability for high-energy density lithium-metal batteries with high-capacity cathodes systems. Such novel nonflammable sulfonamide deep eutectic liquid (DES) with fluorinated ether (TTE) can be utilized in other alkali metal (e.g. Na, K) salt mixtures for other low-cost Na-S or K-S batteries systems, which have prominent thermal degradation issues. In conjunction, this research demonstrates novel carbonization techniques of tunable multimetal MOF-74 nanotemplates as a viable precursor towards the development of various electrocatalyst nickel-based bimetallic alloy nitrogen doped carbon nanocomposite, which can be used as effective functional interlayer materials within LSBs
IMAGINED PLACEMAKING: TIZITA, “PLACEBASED-NOSTALGIA”, AND THE CREATION OF IMMIGRANT SELVES AMONG AMHARA ETHIOPIANS IN MINNESOTA, USA
No full textThis research investigates the experiences of Amhara Ethiopians in Minnesota, USA, emphasizing tizita, “place-based-nostalgia”, imagined placemaking, and creation of immigrant selves, by nuancing a multimodels approach including imagined-ness of community, cultural schema theories, cultural domain analysis, theories of self-construct, and counterfactual thoughts. The primary research methods used include participant observation, key informant interviews, and informal conversations. Formal data was gathered from a total of 70 participants selected based on snowballing, chain referral technique, and analyzed using narrative (discourse) analysis, salience score analysis, and elicitation of self-schemas. The research mainly addressed: How do Amhara immigrants in USA engage in imagined placemaking guided by tizita, “place-based-nostalgia”, rooted in the vitality of history, and reconcile American and Amhara cultural schemas as well as negotiate models of Amhara (non-western) and Western self to create an immigrant self capable of successfully adjusting in American cultural context? It specifically addressed: How history shapes Amhara’s relations with other groups; why Amhara engage in imagined placemaking; major discrepancies and challenges; major conflicting cultural schemas and how they impact adjustment processes; whether Amhara self-concepts changed; and, how negotiating cultural schemas and self-construal models creates contextualized selves. The research finds that, tizita, “place-based-nostalgia”, coupled by historicity, is a crucial aspect of Amhara imagined placemaking. Besides, they reconcile discrepant expectations and realities as well as conflicting home culture and destination culture schemas while strategizing minority ideological resistance, and, without changing their core-self-schemas, create a contextualized self. The research draws how Amhara, coming from a non-western culture, engage in tizita, placemaking, identity consolidation, ideological resistance, and creation of contextualized selves to becoming capable persons in American cultural context. More broadly, it speaks to tizita, “place-based-nostalgia”, as an experience of immigrants in general, although the Amhara situation elaborates a place-based nostalgia and are dealing with a history fraught with the ambiguities of place, it may be the case that imagining a home that is full of ambiguities is something that immigrants in general have to grapple with, and this aspect of the immigrant experience has not been fully appreciated yet, and this dissertation helps to draw attention to it
Distributed Discrete Optimization for Autonomous Restoration in DER-Rich Power Distribution Network
Full text linkTraditionally, advanced distribution management system (ADMS) uses centralized approach for restoration and topology reconfiguration of a power distribution system. However, with increasing penetration of renewable generation with enhanced control variables, energy storage systems, and changing load types, centralized coordination of distributed energy resources for restoration is becoming challenging. Though centralized optimization provides optimal solutions, it also suffers from scalability issues since computation of set points is performed in the ADMS based on all the data collected from sensors in the system. Centralized approach is also prone to single point of failure since it is dependent on network-wide communication for data-delivery. Distributed optimization facilitates parallel computation and distributed decision making while providing near optimum solutions. Advances in sensors, digital automation with remotely controllable switches supports the fully autonomous distributed reconfiguration. Moreover, distributed optimization involves communication only among neighboring agents thereby reducing communication overhead resulting in improved robustness to communication failures and hence enhanced resiliency. This work presents distributed algorithms for optimal restoration for three-phase unbalanced distribution system.The primary contributions of this dissertation are categorized in four sections. First, a decomposable centralized restoration algorithm is developed for an unbalanced power distribution grid. The model can capture effects of grid forming and grid following distributed energy resources in restoration of distribution grid. Second, an open loop model predictive control (MPC) based centralized restoration algorithm is proposed for realization of flexible boundary networked microgrid system in the absence of substations in a feeder. The same formulation is extended for MPC based sequential / multi-step restoration of a distribution grid. The algorithm enables restoration of distribution grid by forming multiple islands around grid forming generators. The sizes of these islands are increased in successive time steps of restoration till the entire network is energized. Third, a novel penalty driven alternating direction method of multipliers (PD-ADMM) based distributed algorithm is proposed for restoration of distribution grid. A detailed scenario assessment is carried out to assess the efficiency of the proposed algorithm. Fourth, a novel distributed discrete proximal atomic coordination algorithm (D^2PAC) is proposed for restoration of distribution grid. Along with performance analysis a comprehensive comparison is carried out to highlight the superiority of D^2PAC over ADMM. The superiority of the proposed algorithms is verified in IEEE 33-bus, 69-bus, 123-bus, and 1069-bus systems
Acoustic cues as a source of social information about food availability
Full text linkAttuning to acoustic information can help animals improve their foraging success. Animals can get information about where to find food through context-specific vocalizations or by hearing aggregations of other animals. Another factor that can influence foraging success is the ability to accurately evaluate when food availability is in decline. However, little is known about whether the acoustic cues produced by animals differ when food is in decline and if these cues can be used as a source of information about food availability. In this thesis, I discuss the use and importance of acoustic social information and present a study on the effect of food availability on the vocal behavior of a nomadic finch, the pine siskin (Spinus pinus). We recorded and characterized the vocalizations of birds that were given either reduced or unrestricted access to food. We found that birds called more frequently when food restricted, and that they specifically increased the production of two particular call types. We also found that in one of those calls types, the minimum frequency was higher when birds were food restricted, and in the other call type the minimum frequency as well as the dominant and fundamental peak frequencies were higher when food was restricted. This work adds to our understanding of how prevailing environmental conditions influence vocal behavior and highlights the potential for vocalizations to be a source of acoustic cues about local food availability
REGULATED DEFICIT IRRIGATION CONSERVES WATER BUT HAS LIMITED IMPACTS ON CIDER APPLE FRUIT AND JUICE QUALITY
Full text linkThe United States has experienced a resurgence in cider apple (Malus domestica Borkh.) production, with Washington State as a leading producer. However, the cider industry is experiencing several challenges, including orchards struggling to meet the demand for cider-specific cultivars, new orchards sometimes having insecure access to irrigation water or only access to high-cost municipal water, and cidermakers trying to differentiate their product in an increasingly crowded market. This project evaluated whether regulated deficit irrigation (RDI) could (1) conserve water while maintaining yield and (2) increase fruit and juice quality to help producers differentiate their products. Trees of four cultivars (Dabinett, Golden Russet, Nehou, and Porter’s Perfection) were managed with either RDI or control irrigation treatments at two distinct locations: Mount Vernon and Wenatchee, WA. In Mount Vernon, no water stress (ψstem) was detected in the trees managed with RDI, though their apple weight and fruit phosphorous decreased by 3.9% and 12.5%, respectively, while fruit firmness increased by 1.2%. In Wenatchee, a decrease in ψstem in trees managed with RDI led to reductions in fruit size (diameter and weight) in both cultivars, bloom density in ‘Golden Russet’, and leaf nutrients (N, P, K, Cu) in ‘Nehou’, as well as increased firmness for both cultivars. Fruit weight decreased by 15.5% and 33.1% for apples from ‘Golden Russet’ and ‘Nehou’ trees managed with RDI, respectively, though there was no statistically detectable decrease in yield. Irrigation was reduced by 100% in Mount Vernon and 40% and 27% for ‘Golden Russet’ and ‘Nehou’, respectively, in Wenatchee. These water reductions resulted in a net gain of $347 per hectare with RDI if irrigation was scheduled using a decision-support tool based on a calculated water balance but even a small decrease in yield (<1%) would offset this gain. No changes in juice quality for fruit from trees managed with RDI were observed in Mount Vernon, but in Wenatchee, there was an increase in specific gravity and soluble sugars. However, implementing RDI neither increased total tannins or total phenolics in the juice at either location, nor resulted in meaningful differences in the phenolic profiles of the juice
Spatial optimization of the sustainable aviation fuel supply chains from forest residues via fast pyrolysis/hydrotreatment considering feedstock ash content variability
No full textPolicymakers and the aviation industry are working to decarbonize commercial flights by replacing conventional jet fuel with sustainable aviation fuel (SAF). Logging residues have been identified as a valuable resource for SAF production. However, the quality of the feedstock, particularly the ash content, can adversely affect bio-oil yield and SAF production using the fast pyrolysis/hydrotreatment process, and potentially its supply chain optimization. Previous research often assumes fixed biofuel yields and neglects the variability in feedstock quality when optimizing the supply chain. Thus, this study seeks to address this gap in the literature by employing a two-stage mixed-integer linear programming (MILP) model to investigate the influence of varying ash content in logging residues on the potential maximum supply quantity (MSQ) and net revenue (NR) of SAF production. Two scenarios were conducted in the Southeastern United States (US): one assuming constant ash content and the other accounting for heterogeneous ash content in logging residues. Results indicate that ignoring ash variability in the feedstock could lead to overestimation of SAF MSQ and NR by 14.15 % and 18.27 %, respectively, in the study area. Additionally, higher ash content leads to lower bio-oil yields, resulting in fewer refineries and reduced capacity. The study emphasizes the need for best management practices to mitigate soil contamination during feedstock processing and improve the resilience of the biomass-based SAF supply chain. Furthermore, it is crucial to effectively manage the mechanisms of mineral uptake and their integration into the structure of lignocellulosic materials.[Display omitted]•A two-stage MILP model optimizes SAF supply chains considering ash content variations.•Ash variability in logging residue considerably affects SAF production and profitability.•Feedstock quality alters optimal refinery locations and sizes across the Southeastern US.•Mitigating soil contamination in biomass feedstock is crucial for a resilient SAF supply chain
Methane Pyrolysis TEA v1.0
No full textThis spreadsheet is a techno-economic analysis model that estimates the minimum selling price of hydrogen (MSPH) for a methane pyrolysis facility, using ratio factors to estimate operating and maintenance costs (OSBL)and user-selected, location-specific assumptions. Users configure scenarios using drop-down menus and editable input cells. The model then generates MSPH results on the Output tab. Additionally, it calculates the carbon intensity of the hydrogen pathway and allows users to optionally account for incentives and carbon capture and storage configurations within each scenario
Auto-thermal Methane Reforming TEA v1.0
No full textThis spreadsheet is a techno-economic analysis model that estimates the minimum selling price of hydrogen (MSPH) for an auto-thermal methane reforming facility, using ratio factors to estimate operating and maintenance costs (OSBL)and user-selected, location-specific assumptions. Users configure scenarios using drop-down menus and editable input cells. The model then generates MSPH results on the Output tab. Additionally, it calculates the carbon intensity of the hydrogen pathway and allows users to optionally account for incentives and carbon capture and storage configurations within each scenario
PERCEPTIONS OF NARCISSISM AND PSYCHOPATHY IN TEAM SPORTS: IMPLICATIONS FOR PERCEIVED TEAM COHESIVENESS, NEGATIVE SOCIAL EXCHANGES, AND INTERNALIZING PROBLEMS
Full text linkThis study examined how psychopathy and narcissism relate to interpersonal perceptions within professional team sport environments. Specifically, perceptions of psychopathic (i.e., antagonism, remorselessness, stress immunity) and narcissistic (i.e., admiration, rivalry) tendencies, as well as other related variables (i.e., leadership, social influence, competitiveness, aggression, manipulativeness, likability), were of interest. The study utilized the Social Relations Model to investigate the relations of self-reported psychopathy and narcissism with the perceptions of teammates among elite athletes on professional handball teams in Israel. The final sample consisted of seven men’s teams and three women’s teams, each composed of 9 to 14 professional athletes (M = 11.5), resulting in a total of 115 participants. The results of this study indicated that self-reported psychopathy and narcissism predicted higher teammate ratings on psychopathy- and narcissism-related traits. In addition, higher self-reported narcissism was associated with perceiving teammates as higher in narcissism-related traits and as less likable. Higher perceptions of team cohesion were associated with more positive teammate ratings (e.g., greater likability) and lower perceptions of psychopathy- and narcissism-related traits. In contrast, more perceived negative social exchanges predicted more negative teammate ratings, including greater perceptions of psychopathic and narcissistic tendencies. There were no significant correlations between perceptions of psychopathic and narcissistic tendencies and internalizing problems. Higher self-reported narcissism was associated with some athletic performance metrics in this sample. The implications of these findings are discussed in terms of the potential advantages and disadvantages of narcissism and psychopathy in team sport contexts