234 research outputs found

    A Tool For Automatic Estimation Of The Stage Height For Ungauged River Sites

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    Recently, River Information Systems that integrate a variety of riverine information have been widely developed, driven by information technologies. The present study attempts to develop a software called HydroConnector that dynamically integrates river-based numerical modeling or post-processing with in situ data, based upon a data searching technique that uses a hydro web service built on top of an ODM-based database, following a CUAHSI standard. It fundamentally differs from the conventional direct access to the database for acquiring a given period of a dataset. Such a hydro web service and ODM-based database were built by utilizing existing real-time stream gaging data, and they are dynamically connected with an HPG model that estimates the stage height for an ungaged site. As a result, the newly developed HydroConnector is very intuitive for the user, due to the user-friendly GUI; it facilitates modeling processes by automatically connecting remotely located data and a specific numerical model, without further laborious data pre- and post-processing. In fact, the HPG model consists of a pre-established diagram based on simulated outputs from one-dimensional river models, such as HEC-RAS, operated for the possible flow conditions, and it is able to estimate the stage height for an ungaged site, driven by the given downstream stage height and upstream flow discharge. The HydroConnector incorporates both the web service and the HPG model, which enables the making of dynamic data pre-processing adjusted for the numerical model, and automatically operates the HPG model, to finally provide the targeted ungaged stage height. Acknowledgement This research was supported by a grant (11-TI-C06) from the Advanced Water Management Research Program, funded by the Ministry of Land, Infrastructure and Transport of the Korean government

    Science Walden: Exploring the Convergence of Environmental Technologies with Design and Art

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    Science Walden, which is inspired by two prominent literary works, namely, Walden by Henry David Thoreau (1817-1862) and Walden Two by Burrhus Frederic Skinner (1904-1990), is aimed at establishing a community that embodies humanistic values while embracing scientific advancement to produce renewable energy and water sources. This study attempts to capitalize on feces standard money (FSM) and artistic collaboration between scientists and artists as a means of achieving the forms of life depicted in Walden and Walden Two. On our campus, we designed and built a pavilion that serves as a laboratory where scientific advantages, design, and art are merged. In the pavilion, feces are processed in reactors and facilities for sustainable energy production, and rainwater is harvested and treated for use in daily life. Our application of design and art contributes to easing interaction between the general public and scientists because it visualizes an ambiguous theory and concretizes it into an understandable image.ope

    Impact of High Methane Flux on the Properties of Pore Fluid and Methane-Derived Authigenic Carbonate in the ARAON Mounds, Chukchi Sea

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    We investigated the pore fluid and methane-derived authigenic carbonate (MDAC) chemistry from the ARAON Mounds in the Chukchi Sea to reveal how methane (CH4) seepage impacts their compositional and isotopic properties. During the ARA07C and ARA09C Expeditions, many in situ gas hydrates (GHs) and MDACs were found near the seafloor. The fluid chemistry has been considerably modified in association with the high CH4 flux and its related byproducts (GHs and MDACs). Compared to Site ARA09C-St 08 (reference site), which displays a linear SO42- downcore profile, the other sites (e.g., ARA07C-St 13, ARA07C-St 14, ARA09C-St 04, ARA09C-St 07, and ARA09C-St 12) that are found byproducts exhibit concave-up and/or kink type SO42- profiles. The physical properties and fluid pathways in sediment columns have been altered by these byproducts, which prevents the steady state condition of the dissolved species through them. Consequently, chemical zones are separated between bearing and non-bearing byproducts intervals under non-steady state condition from the seafloor to the sulfate-methane transition (SMT). GH dissociation also significantly impacts pore fluid properties (e.g., low Cl-, enriched delta D and delta O-18). The upward CH4 with depleted delta C-13 from the thermogenic origin affects the chemical signatures of MDACs. The enriched delta O-18 fluid from GH dissociation also influences the properties of MDACs. Thus, in the ARAON Mounds, the chemistry of the fluid and MDAC has significantly changed, most likely responding to the CH4 flux and GH dissociation through geological time. Overall, our findings will improve the understanding and prediction of the pore fluid and MDAC chemistry in the Arctic Ocean related to CH4 seepage by global climate change

    Potential Benefits from Sharing Rainwater Storages Depending on Characteristics in Demand

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    A rainwater harvesting system (RWHS) is an alternative water resource that collects and stores rainwater from rooftops. It helps smooth out variations in water supply and sustainable water resources management. In this study, we investigated the potential benefits from sharing RWHS with nearby neighbors in a community. We introduced different mean, variance, and correlation in water demand for each water user. A simple case of a community composed of four prospective users is introduced to investigate the benefit from sharing RWHSs. Using the historical rainfall records from four catchments in South Korea, a storage-reliability-yield analysis is applied to obtain the required storage and corresponding reliability for a given yield ratio. The results indicate that the required total storage is reduced when RWHSs are shared among users and the rate of reduction is proportional to the degree of sharing. The required total storage was reduced down to 61% compared to the original storage when RWHSs are shared for a target reliability of 80%. The benefit from sharing also depends on the demands, which are different among users. Test cases with different means and variances as well as correlation disclose the conditions when the benefit from sharing RWHSs is maximized. The result showed that difference in mean and variance additionally reduces the required storage up to 3% and correlation in demand also as much affects the required storage

    CO2 CAPTURE USING POTASSIUM-BASED SOLID SORBENTS IN A BUBBLING FLUIDIZED-BED REACTOR: EFFECTS OF WATER VAPOR PRETREATMENT AND REGENERATING GASES

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