Protonics of perovskite electrocatalysts for energy conversion and storage systems

Department of Energy EngineeringWith the exponential growth in energy consumption and with finite fossil fuel resources, environmentally-friendly and sustainable energy conversion and storage (ECS) devices have received great attention from the industrial and academic communities. Ceramic electrochemical cells such as solid oxide fuel cells(SOFCs) and solid oxide electrolysis cells (SOECs), are considered as promising ECS applications because of their high-energy conversion efficiency and low pollutant emission. Solid oxide fuel cells are high-efficiency energy generation devices that convert chemical energy directly into electricity. As a reverse reaction of the fuel cell reaction, the SOEC is a device capable of producing hydrogen without any pollutants by water electrolysis. Despite these advantages, there are many problems due to the high activation energy of oxygen ion transfer, which requires a very high operating temperature. (e.g., degradation of performance, costly insulation, harsh thermos-cycle environment, slow start-up) In recent years, protonic ceramic fuel cells (PCFC) using a proton conducting oxide (PCO) as an electrolyte, have been attracting attention to solve the drawbacks of high-temperature operation because the PCOs have shown high ionic conductivity and low activation energy of the H+ transport compared with the O2- transport. To operate the PCFC efficiently, the PCFC cathode materials should have the property of electrochemical activity not only for O2- and e??? but also for H+ (so-called triple conducting oxide, TCO). However, due to the difficulties of its characterization, the proton properties of the TCOs are not fully understood yet. In this regard, the characterization of protonics in the TCO is important to understanding applications based on proton conducting oxides. This paper mainly focuses on the understanding and development of perovskite catalysts for ceramic electrochemical cells. In particular, to solve the problems mentioned above, I have comprehensively investigated the thermodynamic and kinetic properties of the oxygen ion, electron, and proton in the perovskite materials. I started with basic principles and theory of overall PCFCs and solid oxide ceramic cell in chapter 1, and then my research papers studying solid oxide fuel cell cathode material and protonic ceramic fuel cell for intermediate to low temperature ceramic fuel cells are presented as follows, 1. Effect of Fe Doping on Layered GdBa0.5Sr0.5Co2O5+?? Perovskite Cathodes for Intermediate Temperature Solid Oxide Fuel Cells 2. Chemically Stable Perovskites as Cathode Materials for Solid Oxide Fuel Cells: La-Doped Ba0.5Sr0.5Co0.8Fe0.2O3-?? 3. Triple-Conducting Layered Perovskites as Cathode Materials for Proton-Conducting Solid Oxide Fuel Cells 4. Hybrid-solid oxide electrolysis cell: A new strategy for efficient hydrogen production 5. The First Observation of Proton Trace in Triple Conducting Oxides: Thermodynamics and Kinetics of Protonope

Centering Panama in Global Modernity: The Search for National Identity and the Imagining of the Orient in Rogelio Sinán’s “Sin novedad en Shanghai”

Since its independence from Colombia in 1903 backed by the United States government, which resulted in a treaty that granted the US free rein to build, administer and control what would be known as the Panama Canal, Panama’s quest for modern nationhood has been severely called into question. More often than not it is posited as an artificial state with little organic unity and limited sovereignty: a state that is literally made in the USA. Panamanian intellectuals, such as Rogelio Sinán, responded to these discourses on the Panamanian nation-state by actively constructing a Panamanian national identity, and by calling attention to the central significance of Panama in the twentieth-century world of global modernity. Questioning the widespread narrative of Panama as a peripheral North American neo-colony that was at best a marginal actor in international history, Sinán positioned Panama at the center of the modern world where World Wars, international migrations and global capitalism connected. By exploring Sinán’s short story “Sin novedad en Shanghai” that takes place in East Asia during World War II, this study argues that the writer’s deployment of the Orient—as a geopolitical, cultural, symbolic and imaginary space—allows him to reposition Panama. In its symbolic relation to this Orient, Panama emerges not as the backwaters of global modernity, but at its center—a cosmopolis between the Orient and the Occident that reveals a microcosm of the modern world

A Cross National Comparison on the Awareness of Adopting FOSS4G to NSDI in Developing Countries

In this study, we constructed an assessment framework that was consisted of 9 indicators about functional, economic and public value for FOSS4G adoption to NSDI and alternatives such as data sharing, data management, utilization and construction and derived relative weights using AHP method. For the AHP, we conducted a survey to developing countries’ 10 respondents from 9 Asian and Latin American countries. Firstly, result of the survey showed that economic value indicator came in the highest weight with 0.425, followed by functional value indicator with 0.345 and public value indicator with 0.230. Secondly, result of the alternatives analysis showed that data sharing alternative came in the highest adoption rate with 0.824, followed by data management with 0.780, data utilization with 0.778. This means that developing countries want to introduce FOSS4G to their NSDI from economic motivation. This study focused on the comprehensive aspect for adopting FOSS4G to NSDI that is different from the previous researches that were focused on the software engineering aspect to the adoption

Multiplex Real-Time Polymerase Chain Reaction-Based Method for the Rapid Detection of gyrA and parC Mutations in Quinolone-Resistant Escherichia coli and Shigella spp.

AbstractTwo real-time polymerase chain reaction assays were developed to detect mutations in codons 83 and 87 in gyrA and in codons 80 and 91 in parC, the main sites that causes quinolone resistance in pathogenic Escherichia coli and Shigella spp. isolates. These assays can be employed as a useful method for controlling infections caused by quinolone-resistant E coli and Shigella isolates

Experimental study of pipe-pile-based micro-scale compressed air energy storage (PPMS-CAES) for a building

Compressed air energy storage (CAES) technology has been re-emerging as one of the promising options to address the challenge coming from the intermittency of renewable energy resources. Unlike the large-scale CAES, which is limited by the geologic location, small- and micro-scale CAES that uses a human-made pressure vessel is adaptable for both grid-connected and standalone distributed units equipped with the energy generation capacity. The research team recently suggested a new concept of pipe- pile-based micro-scale CAES (PPMS-CAES) that uses pipe-pile foundations of a building as compressed air storage vessels. To ascertain the mechanical feasibility of the new concept, we conducted lab-scale pile loading tests with a model test pile in both a loose and dense soil chamber that emulates an actual closed- ended pipe pile. The test pile was subjected to a repeated cycle of compressed air charge (to Pmax=10 MPa) and discharge (to Pmin=0.1 MPa) during the experimental study. The displacement at the top of the test pile, with and without a structural loading, in loose and dense sand, was closely monitored during the repetitive air pressurization-and-depressurization. It was observed that the vertical displacement at the pile head under different conditions was accumulated during the extended cycle of air charge and discharge, but the rate of displacement gradually attenuates during the cycle. And, the presence of structural load and density of soil affected the magnitude of the accumulated vertical displacement. From the analysis, it can be concluded that the concept of PPMS-CAES is not likely to compromise the mechanical integrity of pipe piles while showing a promising capacity for energy storage

Introducing Competition to Boost the Transferability of Targeted Adversarial Examples through Clean Feature Mixup

Deep neural networks are widely known to be susceptible to adversarial examples, which can cause incorrect predictions through subtle input modifications. These adversarial examples tend to be transferable between models, but targeted attacks still have lower attack success rates due to significant variations in decision boundaries. To enhance the transferability of targeted adversarial examples, we propose introducing competition into the optimization process. Our idea is to craft adversarial perturbations in the presence of two new types of competitor noises: adversarial perturbations towards different target classes and friendly perturbations towards the correct class. With these competitors, even if an adversarial example deceives a network to extract specific features leading to the target class, this disturbance can be suppressed by other competitors. Therefore, within this competition, adversarial examples should take different attack strategies by leveraging more diverse features to overwhelm their interference, leading to improving their transferability to different models. Considering the computational complexity, we efficiently simulate various interference from these two types of competitors in feature space by randomly mixing up stored clean features in the model inference and named this method Clean Feature Mixup (CFM). Our extensive experimental results on the ImageNet-Compatible and CIFAR-10 datasets show that the proposed method outperforms the existing baselines with a clear margin. Our code is available at https://github.com/dreamflake/CFM.Comment: CVPR 2023 camera-read