196746 research outputs found
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Understanding epidemic spread patterns:a visual analysis approach
No full textEpidemics present significant challenges for public health policy globally, but current tools for visualizing and analyzing epidemic spread are limited, especially at a large scale. This paper presents a novel visual analysis approach for exploring and comparing pandemic patterns in spatial and temporal dimensions across various regions. The method incorporates a potential flow technique to model the spatiotemporal dynamics of epidemics and a visual exploration tool, EPViz, for interactive data analysis. Utilizing COVID-19 data from Illinois and Pennsylvania in the United States, the paper evaluates the method and tool’s effectiveness. These states were chosen for their differing epidemic scenarios and policies. Additionally, interviews with public health policy experts were conducted to gather feedback on the approach and EPViz’s effectiveness, design, and usability. The findings indicate that this new approach and tool enhance expert understanding, support decision-making, and can inform effective strategies for epidemic prevention and control.</p
Towards Immersive Environments for Declarative Process Models
No full textDeclarative Process Models (DPMs) provide a visual representation of processes based on rules, yet novice users often struggle to understand them, associating representations with imperative flows. This study explores a novel approach by investigating the potential of leveraging 3D gaming environments to represent and execute processes. We conducted semi-structured interviews with experts in 3D modeling, game development, visual arts, and process management to elicit metaphors explaining process behaviors. These metaphors informed the creation of an artifact representing DPMs in 3D worlds in canonical and domain-specific representations. Our validation phase involved think-aloud sessions and semi-structured interviews with novice users to assess their perception and understanding of processes depicted in 3D environments. Results suggest a positive impact of 3D process representations on users’ understanding of declarative process models, with a preference for domain-specific 3D representations. This research contributes to advancing process modeling by addressing challenges faced by novice users and offering innovative solutions within the realm of 3D representations
Micro/nano additives in 3D printing concrete
No full text3D concrete printing has attracted burgeoning interest in the construction industry for its ability to offer cost-effectiveness, architectural design flexibility, efficient use of energy and materials, as well as significant time savings in the construction process. However, conventional cement-geopolymer-based materials cannot be used directly for printing due to their lack of printability. This review explores the utilization of inorganic micro/nanomaterials to modify the rheological and mechanical performance of fresh-state and post-hardening cementitious composites, respectively, offering an in-depth analysis of the mechanisms underpinning their effects. This paper discusses a wide range of inorganic micro/nanomaterials, including carbon-based nanomaterials, silicon-based nanomaterials, metallic oxide nanomaterials, nano-calcium carbonate particles, and other micro/nano-materials. Those materials have been utilized in 3D printing concrete or show considerable potential for future applications in this field. Furthermore, this work provides insights into the multiple applications that arise from the synergistic combination of 3D printing construction techniques with the distinctive properties of different nanomaterials
No one left behind: A universal design analysis of ship evacuation
No full textAn accident on a passenger ferry may lead to evacuation using lifeboats or liferafts, a process that can be both complex and hazardous. This paper investigates the level of safety for passengers during evacuation based on field study and interview data. In the analysis, the eight goals of Universal Design (UD) were tailored and used to explore what ship and interior characteristics influence evacuation performance and the demands placed on the crew and passengers, and whether all passengers have equal chances of completing evacuation safely. Results suggest that while a ship may fulfil regulation, completing an evacuation may pose challenges for passengers with varying abilities, for example, when attempting to perceive emergency information or move through the ship. In addition, it was found that an evacuation may present the crew with challenges and difficult trade-offs that are not always accounted for in the ship's design, equipment and safety organization. It is concluded that the use of a UD approach in ship design, based on a truthful representation of passenger demographics, could enhance passenger safety and provide for evacuation on equal terms
Mesopelagic Fish Traits: Functions and Trade-Offs
No full textFishes inhabiting the mesopelagic zone of the world's oceans are estimated to account for the majority of the world's fish biomass. They have recently attracted new attention because they are part of the biological carbon pump and have been reconsidered as a contribution to food security. Hence, there is an urgent need to understand how environmental conditions and species interactions shape their assemblages, and how they contribute to the functioning of marine ecosystems. Trait-based approaches are valuable for addressing these types of questions. However, the biology and ecology of mesopelagic fishes are understudied compared to fishes in shallow and epipelagic waters. Here, we synthesise existing knowledge of traits of mesopelagic fishes and relate them to their role in survival, feeding and growth and reproduction, the key functions that contribute to fitness. Vertical migrations, specialised vision and the use of bioluminescence are among the most striking adaptations to the conditions in the mesopelagic realm. Many traits are interrelated as a result of trade-offs, which may help to understand selection pressures. While morphological traits are straightforward to observe, major knowledge gaps exist for traits that require frequent sampling, assessment under experimental conditions or age determination. The unique adaptations of mesopelagic fishes need to be included in management strategies as well as fundamental research of the habitat
A germline PAF1 paralog complex ensures cell type-specific gene expression
No full textAnimal germline development and fertility rely on paralogs of general transcription factors that recruit RNA polymerase II to ensure cell type-specific gene expression. It remains unclear whether gene expression processes downstream from such paralog-based transcription is distinct from that of canonical RNA polymerase II genes. In Drosophila, the testis-specific TBP-associated factors (tTAFs) activate over a thousand spermatocyte-specific gene promoters to enable meiosis and germ cell differentiation. Here, we show that efficient termination of tTAF-activated transcription relies on testis-specific paralogs of canonical polymerase-associated factor 1 complex (PAF1C) proteins, which form a testis-specific PAF1C (tPAF). Consequently, tPAF mutants show aberrant expression of hundreds of downstream genes due to read-in transcription. Furthermore, tPAF facilitates expression of Y-linked male fertility factor genes and thus serves to maintain spermatocyte-specific gene expression. Consistently, tPAF is required for the segregation of meiotic chromosomes and male fertility. Supported by comparative in vivo protein interaction assays, we provide a mechanistic model for the functional divergence of tPAF and the PAF1C and identify transcription termination as a developmentally regulated process required for germline-specific gene expression
The Role of Gas Hydrates in Storing Natural Gas-Hydrogen Blends for Coupling Power-to-X and Decarbonization
No full textPower-to-X (PtX) will play a pivotal role in decarbonizing gas-based industries by enabling the conversion of renewable electricity into various forms of energy carriers such as hydrogen and synthetic fuels. By integrating gas hydrates as a storage medium, PtX can effectively link renewable energy sources with the gas-based industry, facilitating a smoother transition toward a low-carbon economy. Hydrogen (H2) storage is a pressing issue due to its low density and the high costs of compression and liquefaction. This study explores the potential of gas hydrate technology for large-scale H2 storage, particularly in blends with natural gas (H2–NG). The research delves into the thermodynamic and kinetic properties of H2–NG hydrates, demonstrating that gas hydrates could offer a viable alternative to traditional storage methods. Experimental and simulation studies indicate that the inclusion of gaseous promoters like methane (CH4) and propane (C3H8) can enhance the H2 storage capacity within hydrates. The study outlines the formation conditions and stability of various hydrate structures, emphasizing the role of promoters in facilitating H2 enclathration. Importantly, the study highlights the practical and feasible pathway for the energy transition by integrating H2 storage into the natural gas infrastructure. The economic analysis underscores the cost-effectiveness of hydrate-based storage compared to conventional methods, considering factors such as energy efficiency and capital expenditure. This study proposes a detailed process for forming, storing, and transporting H2–NG hydrate pellets, highlighting the potential for integrating this method into existing natural gas infrastructures. The findings suggest that, with further optimization, gas hydrate technology could play a crucial role in the H2 economy, offering an efficient and sustainable solution for H2 storage, thus supporting global efforts toward carbon neutrality and clean energy adoption
Blade-resolved and actuator line simulations of rotor wakes
No full textThis work concerns high-fidelity numerical simulations of a rotor wake, with focus on the tip vortices and their stability. Blade-resolved and actuator line lattice-Boltzmann simulations are performed on a symmetric baseline rotor, as well as on a rotor with asymmetries. The asymmetry has the purpose of destabilizing the tip vortices to enhance wake recovery and hence the performance of potential downstream turbines. Limitations in the actuator line method are highlighted, and we show the potential of addressing these limitations with a so-called “preset” actuator line, where the forces are extracted from blade-resolved simulations, or an analytical load model, which as input only requires the thrust and power coefficients. Simulations agree well with experimental results and leapfrogging is captured, even with a coarse actuator line simulation. The asymmetric rotor is shown to improve power in the far-wake by 12%