A Spherical Hybrid Triboelectric Nanogenerator for Enhanced Water Wave Energy Harvesting

Water waves are a continuously generated renewable source of energy. However, their random motion and low frequency pose significant challenges for harvesting their energy. Herein, we propose a spherical hybrid triboelectric nanogenerator (SH-TENG) that efficiently harvests the energy of low frequency, random water waves. The SH-TENG converts the kinetic energy of the water wave into solid-solid and solid-liquid triboelectric energy simultaneously using a single electrode. The electrical output of the SH-TENG for six degrees of freedom of motion in water was investigated. Further, in order to demonstrate hybrid energy harvesting from multiple energy sources using a single electrode on the SH-TENG, the charging performance of a capacitor was evaluated. The experimental results indicate that SH-TENGs have great potential for use in self-powered environmental monitoring systems that monitor factors such as water temperature, water wave height, and pollution levels in oceans.11Ysciescopu

Insang Song's Quick Files

The Quick Files feature was discontinued and it’s files were migrated into this Project on March 11, 2022. The file URL’s will still resolve properly, and the Quick Files logs are available in the Project’s Recent Activity

sigmafelix/autoSTK: v1.2.0

<p>Zenodo submission</p&gt

Multiscale and Spatiotemporal Dynamics of Socioeconomic and Environmental Effects on Mental Illness Mortality

Mental illness is a pressing global and national public health concern, necessitating the identification of risk factors to develop effective prevention measures. In this dissertation, I attempt to fill two research gaps by revealing the spatial and/or temporal disparity in the impacts of unemployment and greenspace on mental illness mortality with spatiotemporal modeling and a causal analysis across three spatial scales.In Chapter 2, the association between mental illness and substance use mortality and unemployment was examined using Bayesian spatiotemporal hierarchical models. The findings revealed heightened positive effects in rural Appalachian and Midwestern counties. Overall mild effects were observed during the Great Recession period. The patterns could be attributed to local contexts such as the availability of healthcare supply and relative deprivation. Chapter 3 challenges the assumption of a spatially constant effect of greenspace exposure on mental illness mortality, using census tract-level data from Oregon and Washington. Results indicated that the impact of greenspace exposure on mental illness mortality varies across census tracts, with protective effects more likely in areas between Seattle and Portland. Protective effects were more likely observed in areas between Seattle and Portland. The contrast between urban and rural areas was explained through factors such as patient preference and differential availability and accessibility to greenspaces. Chapter 4 shed light on the spatial differences in the causal effects of greenspace exposure on mental illness mortality using data from the State of Washington. Dichotomized treatment settings and propensity score matching methods were leveraged to examine the spatial disparity in causal effects of greenspace exposure to mental illness mortality. The results elucidated that the causal effect differed significantly across regions within Washington state, emphasizing that spatial heterogeneity is a critical element when examining the causal effects of greenspace exposure on mental illness mortality. By highlighting the spatial and/or temporal disparity in socioeconomic and physical environment factors’ effects, this dissertation provides new perspectives to spatiotemporal mental health research and suggests a transition from disease mapping to effect mapping. This transition offers evidence to devise locally-focused measures that consider the spatial disparities of associative and causal effects.2024-07-2

sigmafelix/speed: v0.3.0

<p>Zenodo submission</p&gt

Recolonization of native and invasive plants after large-scale clearance of a temperate coastal dunefield

In the management of alien invasive plants in coastal dunes, plot-based approaches have generally been adopted: researchers establish a set of experimental (often topographically homogeneous) plots of a given size where the plants are removed, and recovery patterns are monitored for a period of time. Therefore, the literature still lacks a detailed understanding of where (i.e., under what topographic circumstances) native and invasive species are likely to recolonize after clearance of a large dunefield. In this study, we report on an unprecedented case from the Sindu dunefield in western Korea in which both native and invasive plants had been thoroughly removed to bare sand over a vast area (ca. 11.0 ha), followed by in situ exhaustive mapping of regeneration patterns throughout the entire cleared zone twelve times within four years. The results showed that, after removal, natives and invaders increased to occupy larger (> 50%) areas than those in the pre-removal state. Furthermore, Ecological-Niche Factor Analysis revealed that these two vegetation types exhibited markedly and significantly contrasting regeneration hotspots: invasive plants expanded primarily in low-lying sites that were close to trails. These findings indicate that the recolonization of invasive species was not a spatially random process but rather concentrated along the trails through which local employees transported removed plant material, inadvertently dropping invader propagules. We conclude that removal is often costly, and if executed without a careful plan for the movement of workers, equipment, and plant debris, these efforts may even increase the extent of invasions beyond the initial state.N

Activity Space Assessments to Investigate Neighborhood Exposure to Racism-Related Stress and Related Substance Use Among Young Black Men: Connecticut, 2019

To use activity space assessments to investigate neighborhood exposures that may heighten young Black men\u27s vulnerability to substance use and misuse. We surveyed young Black men in New Haven, Connecticut in 2019 on the locations (activity spaces) they traveled to in a typical week and their experiences of racism and any alcohol and cannabis use at each location. A total of 112 young Black men (mean age = 23.57 years; SD = 3.20) identified 583 activity spaces. There was significant overlap between racism-related events and substance use (alcohol and cannabis use) at specific locations. Areas with a higher prevalence of violent crime also had a greater frequency of racism-related events and substance use. An activity space approach is a promising method for integrating objective and subjective experiences within neighborhood contexts to better understand the frequency and co-occurrence of racism-related stress and substance use among young Black men. (. 2023;113(S2):S136-S139. https://doi.org/10.2105/AJPH.2023.307254)

Web-Based Visualization of Scientific Research Findings: National-Scale Distribution of Air Pollution in South Korea

Background: As scientific findings of air pollution and subsequent health effects have been accumulating, public interest has also been growing. Accordingly, web visualization is suggested as an effective tool to facilitate public understanding in scientific evidence and to promote communication between the public and academia. We aimed to introduce an example of easy and effective web-based visualization of research findings, relying on predicted concentrations of particulate matter ≤ 10 µg/m3 (PM10) and nitrogen dioxide (NO2) obtained from our previous study in South Korea and Tableau software. Our visualization focuses on nationwide spatial patterns and temporal trends over 14 years, which would not have been accessible without our research results. Methods: Using predicted annual average concentrations of PM10 and NO2 across approximately 250 districts and maps of administrative divisions in South Korea during 2001–2014, we demonstrate data preprocessing and design procedures in the Tableau dashboard, comprising maps, time-series plots, and bar charts. Results: Our visualization allows one to identify high concentration areas, a long-term temporal trend, and the contrast between two pollutants. The application of easy tools for user-interactive options in Tableau suggests possible easy access to the scientific knowledge of non-experts. Conclusion: Our example contributes to future studies that develop the visualization of research findings in further intuitive designs

Changes in spatial clusters of cancer incidence and mortality over 15 years in South Korea: Implication to cancer control

Abstract Background The temporal investigation of high‐risk areas of cancer incidence and mortality can provide practical implications in cancer control. We aimed to investigate the changes in spatial clusters of incidence and mortality from 1999 through 2013 by major cancer types in South Korea. Methods We applied flexible scan statistics to identify spatial clusters of cancer incidence and mortality by three 5‐year periods and seven major cancer types using the counts of new cases and deaths and population in 244 districts during 1999–2013. Then, we compared the changes across three periods in the locations of primary clusters of incidence and mortality by cancer types. To explore the determinants that possibly affect cancer cluster areas, we compared geographic characteristics between clustered and non‐clustered areas. Results While incidence clusters for lung, stomach, and liver cancer remained in the same areas over 15 years, mortality clusters were relocated to the areas similar to those of incidence clusters. In contrast, colorectal, breast, cervical, and prostate cancer displayed consistently different locations of clusters over time, indicating the disappearance of existing clusters and the appearance of new clusters. Cluster areas tended to show higher portions of older population, unemployment, smoking, and cancer screening compared to non‐cluster areas particularly for mortality. Conclusions Our findings of diverse patterns of changes in cancer incidence and mortality clusters over 15 years can indicate the degree of effectiveness in cancer prevention and treatment depending on the area and suggest the need for area‐specific applications of different cancer control programs