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2. Tsunami Debris Damming Forces and Associated Coefficients for Elevated Coastal Structure Columns: Experimental Comparison to ASCE 7-22 Minimum Design Loads.

Author

Doyle, Kellen, Koh, Myung Jin, Jayasekara, Jayasekara R., Cox, Daniel, Park, Hyoungsu, Kameshwar, Sabarethinam, and Lomonaco, Pedro

Subjects
TSUNAMI hazard zones, DRAG (Aerodynamics), INFRASTRUCTURE (Economics), LATERAL loads, SHIPPING containers, DRAG coefficient
Abstract

Debris damming forces of 1∶20 -scale shipping containers freely accumulated against elevated coastal structure columns were experimentally determined to evaluate ASCE 7-22 tsunami-resilient design standards. Three inundation conditions were generated to represent Froude regimes estimated in posttsunami field studies. Three different column array densities and two different shipping container sizes were evaluated. A photogrammetric method was employed to estimate the submerged projected area of in situ transient debris dams from two synchronized camera perspectives. Relative to this experimental data, it was found that the ASCE 7-22 equation for simplified equivalent uniform lateral static pressure is conservative by a mean factor of safety of 14.6 and performs as intended given the prescribed scope. Similarly, the ASCE 7-22 equation for detailed hydrodynamic lateral forces yielded a lower mean factor of safety of 2.4 but maintained design conservatism across all tested experimental conditions, also performing as intended. Minimum closure ratios and overall structure drag coefficients serve as input values for these detailed hydrodynamic lateral design loads. The proportion of closure coefficients prescribed by ASCE 7-22 tend to be reasonably conservative in general, and any instances of experimental exceedance of these design values did not appear to affect the design conservatism of Eq. (3). Finally, drag coefficients for rectilinear structures prescribed by ASCE 7-22 appear unrepresentative of coastal structures, which tend to generate column-flow interactions and unbalanced hydrostatic conditions. It is therefore suggested that the flow resistance of such structures be quantified via a bulk resistance coefficient, indicated by recent literature as a more appropriate measure applicable to surface-piercing flow obstructions. Practical Applications: Since the 2016 adoption of tsunami-resilient design standards in ASCE 7-16, debris damming design loads have yet to be thoroughly examined. The results of this experiment indicate that the application of hydrodynamic loading equations in ASCE 7-22 Section 6.10 is conservative across all tested experimental conditions. Debris accumulation on the seaward face of the modeled structure is generally conservative relative to the design proportion of closure coefficients, and instances of exceedance do not result in unconservative load prediction. Finally, drag coefficients for rectilinear structures may not capture phenomena associated with surface-piercing flow obstructions such as column-flow interactions and unbalanced hydrostatic forces. It is suggested that a bulk resistance coefficient be adopted to account for both form drag and surface effects of flow around elevated coastal structure columns. Accurate quantification of tsunami-induced loads is crucial to the design of critical and essential infrastructure located within tsunami inundation zones, especially vertical evacuation refuge structures. [ABSTRACT FROM AUTHOR]

Published
2025
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5. Hydrogen Peroxide : Signaling Mechanisms and Crosstalk in Plant Development and Stress Responses

Author

Mohd Tanveer Alam Khan, Taiba Saeed, Aqeel Ahmad, Qazi Fariduddin, Mohammad Yusuf, Mohd Tanveer Alam Khan, Taiba Saeed, Aqeel Ahmad, Qazi Fariduddin, and Mohammad Yusuf

Subjects
Plant cellular signal transduction, Hydrogen peroxide, Plants--Effect of stress on, Plant defenses
Abstract

Hydrogen peroxide (H2O2) is recognized as a crucial signaling molecule that mediates physiological and biochemical processes in plants, regulating various development and stress responses. Hydrogen Peroxide: Signalling Mechanisms and Crosstalk in Plant Development and Stress Responses presents a comprehensive overview of hydrogen peroxide's modes of action in plants demonstrating the important role played in plant stress signaling and communication. It introduces key topics in H2O2 research such as plant signaling, molecular responses, and interaction with other hormones.Features Discusses experiments interrelated to H2O2 signaling pathway in plants under various environmental conditions Addresses important concerns in H2O2 research from a wide range of organisms, including plants and prokaryotes such as bacteria and archaea Collects, summarizes, and presents developments in plant signaling and communication Aids scientists and breeders in developing strategies to enhance plant growth and stress tolerance Environmental stress is destructively disturbing plant growth and efficiency resulting in concerns to improve food crop yield, and H2O2 has immense field implications as it is vital in regulating plant growth and stress responses. Hydrogen Peroxide: Signalling Mechanisms and Crosstalk in Plant Development and Stress Responses is an invaluable resource for researchers and scientists to use as a guide to conduct studies on environmental conditions of the plant hydrogen peroxide signaling systems.

Published
2025

6. Advances in Geospatial Technologies for Natural Resource Management

Author

Ravi Shankar Dwivedi and Ravi Shankar Dwivedi

Subjects
Natural resources--Remote sensing, Geospatial data, Environmental monitoring--Remote sensing, Conservation of natural resources
Abstract

Timely and reliable information on natural resources, regarding their potential and limitations, is a prerequisite for sustainable development. Geospatial technologies offer immense potential in providing such information in a timely and cost-effective manner. Using orbital sensors data in conjunction with airborne and proximal sensors data to generate information on soils and agricultural resources, forests, mineral resources, fossil fuel, wetlands, water resources, and marine resources, this book focuses on the advancements in technologies applicable to managing these resources. It addresses global issues like climate change and land degradation neutrality and introduces spatial data infrastructure (SDI) as a mechanism for sharing geospatial data. This book also provides an in-depth discussion on drones, crowdsourcing, cloud computing, Internet of Things, machine learning, and their applications.FEATURES Contains a comprehensive resource on the latest developments in geospatial technologies and their use in monitoring natural resources, productivity mapping, and modeling Explains the geo-computation methods and online algorithm developments Includes clear guidance on how best to use geospatial data for various applications Discusses case studies from a variety of fields and current trends in the management of natural resources Provides future scenarios concerning platforms, sensors, data analysis, and interpretation techniques This book is written for remote sensing and GIS professionals in environmental institutions and government who are involved in natural resource management projects. Senior undergraduate and graduate-level students in Earth sciences, geography, or environmental management can also use this text for supplementary reading.

Published
2025

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