Far from the plate boundaries, the seismogenic zones within the cratonic areas of Indian land mass had remained largely undetected. The moderate earthquakes in such areas have proved to be hugely damaging because of their infrequency and consequent lack of societal preparedness. As the subtle geological expressions of tectonism make identifying hazardous zones in cratonic areas difficult, it is important to develop locally appropriate geological criteria to isolate potential seismic source zones. Although seismically induced liquefaction preserved in the sedimentary sections is useful as an earthquake proxy, its scope remains underestimated in cratonic regions. Here we offer a field-based methodological approach to mapping liquefaction features from such an area, located south of the Bharathapuzha River in the southwestern part of the Indian craton. We used the field data to constrain the near-field earthquake potential. The earthquake-induced soil liquefaction, in the form of sand dikes and sills, was identified within an area of roughly 100 km2, and the available data suggest two episodes of liquefaction - the one between 2.0 ka and 2.5 ka, and a later event around 0.78 ka BP. The spatial distribution and the dimension of the soil liquefaction features, in an area known for the occasional spurt in minor earthquakes in recent times, are suggestive of a potential seismic source in the region that can generate earthquakes of moment magnitudes (Mw) ranging from 5.5 to 6.5. Thus the present observation is a vital input for constraining the region's seismic hazard and the methodology developed here can be used in other areas of unknown potential.

German coastal areas are often protected from flood events by a primary sea dike line of more than 1,200 km. Many transition areas, such as the change of surface covering materials and other dike elements such as stairs, fences, or ramps at intermittent locations, characterize the stretch of this sea dike line. During storm surges and wave overtopping, the onset of damage, especially dike cover erosion, is often initiated at these transitions due to locally disturbed flow characteristics, increased loads, and reduced strength at the interface. An in-depth understanding of damage initiation and building stock conditions along coastlines as a foundational element of a flood cycle is essential in order to accurately assess existing defense structures, both deterministically and probabilistically. Thus, the present study is motivated to examine the variety of transition areas on the sea dikes along the German coasts, for further assessment of probability of their damage and failure. A novel remote inventory was elaborated manually, based on satellite images for a length of 998 km along the German North Sea and 123 km along the German Baltic Sea coast and estuaries, and it shows the spatial distribution and frequency of such transitions on sea dikes. During additional on-site investigations at different locations at the coast, detailed information about design variants of dike elements as well as damage to transitions were recorded and reported systematically. The results of the on-site investigations allow the development of a damage catalog in relation to transitions and the validation and verification of the remote inventory. By categorizing and spatially analyzing a large number of transitions (n approximate to 18,300) and damages along the coast, particularly vulnerable transitions and hot spots of loading can be further investigated regarding the flow-structure-soil interaction. Through this, structural layouts and material combinations can be optimized for the design of sea dikes.

Double-layer dike foundation is composed of a weakly permeable overlying clay layer and a highly permeable underlying sand layer, which is one of the most common stratum types in dike engineering with the highest probability of catastrophic damage, and the main danger is backward erosion piping. Existing research on backward erosion piping of double-layer dike foundation has not fully considered the influence of the exit on the erosion process. Therefore, a self-designed test device is used to assess the influences of the size, position and type of different exits, and the circular exit is connected with the slot exit via the exit area to explore the critical identification conditions and the pipe development mechanism toward the upstream direction under different exit geometry conditions. The results show that both the local and global hydraulic gradients borne by the exit are inversely proportional to the exit area and are less notably affected by the location of the exit. The development process of slot exit pipes differs from that of circular exit pipes, and pipes are usually developed alternately at the two corners of the exit near the upstream end and then converge into one pipe. The average pipe depth and width are proportional to the exit size and the seepage length. With increasing average pipe area of the slot exit, pipes develop more rapidly after head enhancement, and the damage to the dike foundation increases.

Background: The high toxicity of hexavalent chromium [Cr (VI)] could not only cause harmful effects on humans, including carcinogenicity, respiratory issues, genetic damage, and skin irritation, but also contaminate drinking water sources, aquatic ecosystems, and soil, impairing the reproductive capacity, growth, and survival of organisms. Due to these harmful effects, detecting toxic Cr (VI) is of great significance. However, the rapid, simple, and efficient detection at a low Cr (VI) concentration is extremely challenging, especially in an acidic condition (existing as HCrO 4 - ) due to its low adsorption free energy. Results: A diketopyrrolopyrrole-based small molecule (DPPT-PhSMe) is designed and characterized to act as a chemosensor, which allows a high selectivity to Cr (VI) at an acidic condition with a low limit of detection to 10 -8 M that is two orders of magnitude lower than the cut of limit (1 mu M) recommended by World Health Organization (WHO). Mechanism study indicates that the rich sulfur atoms enhance the affinity to HCrO 4 - . Combining with favorable features of diketopyrrolopyrrole, DPPT-PhSMe not only allows dual -mode detection (colorimetric and spectroscopic) to Cr (VI), but also enables disposable paper -based sensor for naked -eye detection to Cr (VI) from fully aqueous media. The investigation of DPPT-PhSMe chemosensor for the quanti- fication of Cr (VI) in real life samples demonstrates a high reliability and accuracy with an average percentage recovery of 102.1 % +/- 4 (n = 3). Significance: DPPT-PhSMe represents the first diketopyrrolopyrrole-derived chemosensor for efficient detection to toxic Cr (VI), not only providing a targeted solution to the bottleneck of Cr (VI) detection in acidic conditions (existing as HCrO 4 - ) caused by its low adsorption free energy, but also opening a new scenario for simple, se- lective, and efficient Cr (VI) detection with conjugated dye molecules.