4,200 research outputs found
UMSL Bulletin 2023-2024
The 2023-2024 Bulletin and Course Catalog for the University of Missouri St. Louis.https://irl.umsl.edu/bulletin/1088/thumbnail.jp
Advanced Nanomaterials for Electrochemical Energy Conversion and Storage
This book focuses on advanced nanomaterials for energy conversion and storage, covering their design, synthesis, properties and applications in various fields. Developing advanced nanomaterials for high-performance and low-cost energy conversion and storage devices and technologies is of great significance in order to solve the issues of energy crisis and environmental pollution. In this book, various advanced nanomaterials for batteries, capacitors, electrocatalysis, nanogenerators, and magnetic nanomaterials are presente
Weather or not? The role of international sanctions and climate on food prices in Iran
IntroductionThe scarcity of resources have affected food production, which has challenged the ability of Iran to provide adequate food for the population. Iterative and mounting sanctions on Iran by the international community have seriously eroded Iran's access to agricultural technology and resources to support a growing population. Limited moisture availability also affects Iran's agricultural production. The aim of this study was to analyze the influence of inflation, international sanctions, weather disturbances, and domestic crop production on the price of rice, wheat and lentils from 2010 to 2021 in Iran.MethodData were obtained from the statistical yearbooks of the Ministry of Agriculture in Iran, Statistical Center of Iran, and the Central Bank of Iran. We analyzed econometric measures of food prices, including CPI, food inflation, subsidy reform plan and sanctions to estimate economic relationships. After deflating the food prices through CPI and detrending the time series to resolve the non-linear issue, we used monthly Climate Hazards group Infrared Precipitation with Stations (CHIRPS) precipitation data to analyze the influence of weather disturbances on food prices.Results and discussionThe price of goods not only provides an important indicator of the balance between agricultural production and market demand, but also has strong impacts on food affordability and food security. This novel study used a combination of economic and climate factors to analyze the food prices in Iran. Our statistical modeling framework found that the monthly precipitation on domestic food prices, and ultimately food access, in the country is much less important than the international sanctions, lowering Iran's productive capability and negatively impacting its food security
Bio-inspired optimization in integrated river basin management
Water resources worldwide are facing severe challenges in terms of quality and quantity. It is essential to conserve, manage, and optimize water resources and their quality through integrated water resources management (IWRM). IWRM is an interdisciplinary field that works on multiple levels to maximize the socio-economic and ecological benefits of water resources. Since this is directly influenced by the river’s ecological health, the point of interest should start at the basin-level. The main objective of this study is to evaluate the application of bio-inspired optimization techniques in integrated river basin management (IRBM). This study demonstrates the application of versatile, flexible and yet simple metaheuristic bio-inspired algorithms in IRBM.
In a novel approach, bio-inspired optimization algorithms Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO) are used to spatially distribute mitigation measures within a basin to reduce long-term annual mean total nitrogen (TN) concentration at the outlet of the basin. The Upper Fuhse river basin developed in the hydrological model, Hydrological Predictions for the Environment (HYPE), is used as a case study. ACO and PSO are coupled with the HYPE model to distribute a set of measures and compute the resulting TN reduction. The algorithms spatially distribute nine crop and subbasin-level mitigation measures under four categories. Both algorithms can successfully yield a discrete combination of measures to reduce long-term annual mean TN concentration. They achieved an 18.65% reduction, and their performance was on par with each other. This study has established the applicability of these bio-inspired optimization algorithms in successfully distributing the TN mitigation measures within the river basin.
Stakeholder involvement is a crucial aspect of IRBM. It ensures that researchers and policymakers are aware of the ground reality through large amounts of information collected from the stakeholder. Including stakeholders in policy planning and decision-making legitimizes the decisions and eases their implementation. Therefore, a socio-hydrological framework is developed and tested in the Larqui river basin, Chile, based on a field survey to explore the conditions under which the farmers would implement or extend the width of vegetative filter strips (VFS) to prevent soil erosion. The framework consists of a behavioral, social model (extended Theory of Planned Behavior, TPB) and an agent-based model (developed in NetLogo) coupled with the results from the vegetative filter model (Vegetative Filter Strip Modeling System, VFSMOD-W). The results showed that the ABM corroborates with the survey results and the farmers are willing to extend the width of VFS as long as their utility stays positive. This framework can be used to develop tailor-made policies for river basins based on the conditions of the river basins and the stakeholders' requirements to motivate them to adopt sustainable practices.
It is vital to assess whether the proposed management plans achieve the expected results for the river basin and if the stakeholders will accept and implement them. The assessment via simulation tools ensures effective implementation and realization of the target stipulated by the decision-makers. In this regard, this dissertation introduces the application of bio-inspired optimization techniques in the field of IRBM. The successful discrete combinatorial optimization in terms of the spatial distribution of mitigation measures by ACO and PSO and the novel socio-hydrological framework using ABM prove the forte and diverse applicability of bio-inspired optimization algorithms
Planar-type silicon thermoelectric generator with phononic nanostructures for 100 {\mu}W energy harvesting
Energy harvesting is essential for the internet-of-things networks where a
tremendous number of sensors require power. Thermoelectric generators (TEGs),
especially those based on silicon (Si), are a promising source of clean and
sustainable energy for these sensors. However, the reported performance of
planar-type Si TEGs never exceeded power factors of 0.1
due to the poor thermoelectric performance of Si and the suboptimal design of
the devices. Here, we report a planar-type Si TEG with a power factor of 1.3
around room temperature. The increase in thermoelectric
performance of Si by nanostructuring based on the phonon-glass electron-crystal
concept and optimized three-dimensional heat-guiding structures resulted in a
significant power factor. In-field testing demonstrated that our Si TEG
functions as a 100--class harvester. This result is an essential step
toward energy harvesting with a low-environmental load and cost-effective
material with high throughput, a necessary condition for energy-autonomous
sensor nodes for the trillion sensors universe
Emerging Power Electronics Technologies for Sustainable Energy Conversion
This Special Issue summarizes, in a single reference, timely emerging topics related to power electronics for sustainable energy conversion. Furthermore, at the same time, it provides the reader with valuable information related to open research opportunity niches
Additively Manufactured Shape-changing RF Devices Enabled by Origami-inspired Structures
The work to be presented in this dissertation explores the possibility of implementing origami-inspired shape-changing structures into RF designs to enable continuous performance tunability as well as deployability. The research not only experimented novel structures that have unique mechanical behaviour, but also developed automated additive manufacturing (AM) fabrication process that pushes the boundary of realizable frequency from Sub-6 GHz to mm-wave. High-performance origami-inspired reconfigurable frequency selective surfaces (FSSs) and reflectarray antennas are realized for the first time at mm-wave frequencies via AM techniques. The research also investigated the idea of combining mechanical tuning and active tuning methods in a hybrid manner to realize the first truly conformal beam-forming phased array antenna that can be applied onto any arbitrary surface and can be re-calibrated with a 3D depth camera.Ph.D
A Comparative Study of Vehicle Platoon with Limited Output Information in Directed Topologies
This paper aims to study and compare the effect of limited-output information in various directed topology to the performance of vehicle platoon. Two distributed controllers based on limited-output information will be compared to cooperative state variable feedback control which designed based on full-state information. The comparison will be conducted for four common directed topologies in the vehicle platoon application. Simulation analysis is performed in three scenarios, namely under normal operations, when the leader moves with constant acceleration and when the platoon is subjected to constant communication delay. Performances comparison will be observed from inter-vehicular distance response in each follower and the results will be displayed with respect to the follower vehicle index in the platoon configuration. Finally, the behavior of each control scheme in various topologies will be summarized
Exploring the properties of liquid metals in electrochemical systems
Low melting point post-transition metals and alloys, dubbed as liquid metals (LMs), have emerged as group of soft yet conductive materials with remarkable physical and chemical properties. The enigmatic features of LMs originate from their deformable and electron-rich core as well as their atomically smooth and chemically active interface. These features can offer opportunities for designing novel electrochemical systems with improved performance and applicability. Despite the great potential, LM-based electrochemical modules are at nascent stage and the fundamental knowledge regarding electric field-induced events at LMs/electrolyte interfaces is still elusive. The present thesis focuses on the incorporation of LMs and LM-based materials in different electrochemical set-ups. The outcomes showcase the capability of LMs for materials synthesis, biosensing, and alloy processing via electrochemical routes.
In chapter 3 of this thesis, the author focuses on the exploitation of autogenous interfacial potential generated on gallium and indium eutectic alloy, EGaIn, to drive a galvanic reduction reaction (GRR). It is revealed that EGaIn could effectively reduce graphene oxide (GO) in different configurations to produce monolayers and thick membranes of reduced GO (rGO) as well as LM droplets covered with a shell of rGO flakes.
In chapter 4, the core-shell structures of LM-rGO, synthesized via GRR, were electrochemically characterized through their incorporation as a modifier to electrochemical interfaces. The author revealed that incorporation of the LM-based modifier results in improved charge transfer kinetics, higher electroactive surface area, and lower resistance. The remarkable electrochemical performance of LM-rGO particles were exploited for selective biosensing of dopamine using both paper-based devices and conventional electrochemical set-ups.
In chapter 5, droplets of a gallium- and an indium-based LM eutectic alloys were electrochemically diagnosed to explore interfacial events occurring at LM/electrolyte interface. The author showed that upon surface perturbation by a cathodic voltage, solute elements tend to segregate at the interface according to their energy levels. The electrolyte solution was observed to have a substantial effect on the composition of segregated domains.
Collectively, this PhD research demonstrates opportunities for designing novel electrochemical systems based on LMs and provides valuable insights into voltage-dependent behaviour of LMs, which can potentially contribute to the advancement of scientific fields such as materials processing, energy, and sensors
3D/4D printing of cellulose nanocrystals-based biomaterials: Additives for sustainable applications
Cellulose nanocrystals (CNCs) have gained significant attraction from both industrial and academic sectors, thanks to their biodegradability, non-toxicity, and renewability with remarkable mechanical characteristics. Desirable mechanical characteristics of CNCs include high stiffness, high strength, excellent flexibility, and large surface-to-volume ratio. Additionally, the mechanical properties of CNCs can be tailored through chemical modifications for high-end applications including tissue engineering, actuating, and biomedical. Modern manufacturing methods including 3D/4D printing are highly advantageous for developing sophisticated and intricate geometries. This review highlights the major developments of additive manufactured CNCs, which promote sustainable solutions across a wide range of applications. Additionally, this contribution also presents current challenges and future research directions of CNC-based composites developed through 3D/4D printing techniques for myriad engineering sectors including tissue engineering, wound healing, wearable electronics, robotics, and anti-counterfeiting applications. Overall, this review will greatly help research scientists from chemistry, materials, biomedicine, and other disciplines to comprehend the underlying principles, mechanical properties, and applications of additively manufactured CNC-based structures
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