Obeng Appiagyei Addai

Flood health burdens extend beyond inundation through displacement, service disruption, contaminated environments, and delayed disease. These processes are often modeled separately or as cause–effect relationships, limiting analysis of feedbacks among human behavior, institutions, and post-flood health. We present the Flood-Disease Agent-Based Model (Flood-Disease ABM), a spatially explicit, hourly modeling framework that integrates flood exposure, human mobility, worldview-informed decision-making, institutional response, economic activity, quality of life, and infectious, vector-borne, and mold-related respiratory disease pathways. Decision-making is differentiated across hierarchist, egalitarian, individualist, and fatalist worldview orientations. A browser-based interactive app enables users to configure scenarios, populations, hazards, service capacity, and policy assumptions and to observe spatial and temporal outcomes. Complementary batch runners support reproducible replications of the same configurations. The framework is implemented for the flood-prone Uvalde, Texas, region using representations of households, businesses, schools, shelters, healthcare facilities, and government. Under the selected assumptions, the compound scenario produces an early flood-related healthcare peak followed by sustained disease-related demand during recovery; mold emerges after floodwater recession; spatially uneven shelter demand exceeds capacity at peak demand; financial stress shifts among households and institutions; and quality-of-life losses are greatest among children and lower-income groups. Results are model-based outcomes and not calibrated forecasts for Uvalde.

Flood health burdens extend beyond inundation through displacement, service disruption, contaminated environments, and delayed disease. These processes are often modeled separately or as cause–effect relationships, limiting analysis of feedbacks among human behavior, institutions, and post-flood health. We present the Flood-Disease Agent-Based Model (Flood-Disease ABM), a spatially explicit, hourly modeling framework that integrates flood exposure, human mobility, worldview-informed decision-making, institutional response, economic activity, quality of life, and infectious, vector-borne, and mold-related respiratory disease pathways. Decision-making is differentiated across hierarchist, egalitarian, individualist, and fatalist worldview orientations. A browser-based interactive app enables users to configure scenarios, populations, hazards, service capacity, and policy assumptions and to observe spatial and temporal outcomes. Complementary batch runners support reproducible replications of the same configurations. The framework is implemented for the flood-prone Uvalde, Texas, region using representations of households, businesses, schools, shelters, healthcare facilities, and government. Under the selected assumptions, the compound scenario produces an early flood-related healthcare peak followed by sustained disease-related demand during recovery; mold emerges after floodwater recession; spatially uneven shelter demand exceeds capacity at peak demand; financial stress shifts among households and institutions; and quality-of-life losses are greatest among children and lower-income groups. Results are model-based outcomes and not calibrated forecasts for Uvalde.

The guest-host liquid crystal display, first proposed in 1968, relies on controlling the orientation of dichroic dyes dissolved in a nematic liquid crystal host. Controlling the orientation of the liquid crystal and of the dissolved dye with an electric field allows control of the transmittance of the cell. Knowing the dielectric properties at optical frequencies of the dye and liquid crystal mixtures is crucial for the optimal design of guest-host liquid crystal devices. In this work, the dielectric functions of various layers in liquid crystal cells are described by models obeying the Kramers-Kronig relations: the Sellmeier equation for transparent layers and the causal Gaussian oscillator model for absorbing layers. We propose a systematic way to accurately model the dielectric response of each layer by minimising the sum of squared differences between the measured transmittance spectrum of a guest-host cell in the near-UV/vis range and the prediction of the transmittance of the modelled multilayer structure. By measuring the transmittance for incident light polarised parallel and perpendicular to the nematic director allows us to separately characterise the two principal dielectric functions of the uniaxial sample. Our results show that the causal Gaussian oscillator model can accurately characterise the dielectric functions of dyes in liquid crystals. GRAPHICAL ABSTRACT

The guest-host liquid crystal display, first proposed in 1968, relies on controlling the orientation of dichroic dyes dissolved in a nematic liquid crystal host. Controlling the orientation of the liquid crystal and of the dissolved dye with an electric field allows control of the transmittance of the cell. Knowing the dielectric properties at optical frequencies of the dye and liquid crystal mixtures is crucial for the optimal design of guest-host liquid crystal devices. In this work, the dielectric functions of various layers in liquid crystal cells are described by models obeying the Kramers-Kronig relations: the Sellmeier equation for transparent layers and causal Gaussian oscillator model for absorbing layers. We propose a systematic way to accurately model the dielectric response of each layer by minimizing the sum of squared differences between the measured transmittance spectrum of a guest-host cell in the near-UV/vis range and the prediction of the transmittance of the modeled multilayer structure. By measuring the transmittance for incident light polarized parallel and perpendicular to the nematic director allows us to separately characterize the two principal dielectric functions of the uniaxial sample. Our results show that the causal Gaussian oscillator model can accurately characterize the dielectric functions of dyes in liquid crystals.