Sediment processes

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  • The use of models to provide additional details on contaminant fate and transport has rapidly increased in the past 3 decades. The increasing global recognition of the potential risks associated with surface water or ground water contamination and speciÞc environmental regulations implemented after 1980 have demanded a more accurate understanding of these risks as they relate to human health and the environment.

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  • Sediment Transport Processes and their Modelling Applications is a book which covers a wide range of topics. The effective management of many aquatic environments, requires a detailed understanding of sediment dynamics. This has both environmental and economic implications, especially where there is any anthropogenic involvement. Numerical models are often the tool used for predicting the transport and fate of sediment movement in these situations, as they can estimate the various spatial and temporal fluxes.

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  • Sediment transport is a book that covers a wide variety of subject matters. It combines the personal and professional experience of the authors on solid particles transport and related problems, whose expertise is focused in aqueous systems and in laboratory flumes. This includes a series of chapters on hydrodynamics and their relationship with sediment transport and morphological development.

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  • The search for oil occurs in geological sediments, as opposed to volcanic rocks. Several processes are involved in the creation of sediments. First, the inland continental volcanic rock is continuously being weakened and eroded by weathering processes (mechanical (through water, ice and wind) and chemical erosion). Secondly and simultaneously, the eroded material is being transported by water, ice and wind and gradually the material may be broken down into smaller pieces (from boulders to gravel, to sand, to silt and finally to clay).

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  • Carmago et al. (1992) noted that short-term flow fluctuations, low concentration of dissolved oxygen and also the siltation of suspended inorganic matter caused by industrial discharge contribute greatly to the changes in sediment and directly affect the structure of macroinvertebrate community. The high siltation of suspended inorganic matter caused significant reductions in taxa richness and abundance of zoobenthic communities as it changes the natural structure of the substratum.

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  • The purpose of this collection is to present some of the diversity of ideas and studies about species that can be classifi ed as “ecosystem engineers.” As with any developing concept, we fi nd disagreement about the meaning and usefulness of this term in the literature and among ourselves. The idea for the book arose in a National Center for Ecological Analysis and Synthesis (NCEAS) working group designed to develop models of ecosystem engineering species.

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  • Tuyển tập các báo cáo nghiên cứu khoa học ngành toán học được đăng trên tạp chí toán học quốc tế đề tài: A new approach to investigate the interactions between sediment transport and ecotoxicological processes during flood events

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  • The Society makes every effort to ensure that the scientific and production quality of its books matches that of its journals. Since 1997, all book proposals have been refereed by specialist reviewers as well as by the Society’s Books Editorial Committee. If the referees identify weaknesses in the proposal, these must be addressed before the proposal is accepted. Once the book is accepted, the Society Book Editors ensure that the volume editors follow strict guidelines on refereeing and quality control.

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  • There has been considerable debate in Canada on the relative contributions of mercury from natural sources versus releases to the environment from human activity. One of the challenges with this debate is the lack of accurate information on mercury emissions, past and present. Scientists have ana- lyzed sediment cores and determined that the levels of mercury in the environment today are more than double what they were in pre-industrial times. They have also measured mercury in the atmos- phere and found that it continues to increase globally at more than one per cent per year.

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  • The deposition in Day estuary tends to increase strongly due to abundant sources of sediment from the Red River system and the estuary is located in a concave coast where strong impacts of wave are eliminated. In this study, MIKE model developed by Danish Hydraulic Institute is employed to simulate, evaluate and forecast hydrodynamic regime as well as erosion, sedimentation and shoreline change processes in Day river mouth located in Ninh Binh.

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  • Fenton's Reagent requires soluble Fe2+ to form OH•. This optimal reaction occurs under relatively low pH conditions (e.g., pH of 2 to 4). pH adjustment in the treatment area is often necessary to enable the oxidation process to proceed efficiently. This can be accomplished by either acidifying the hydrogen peroxide or by adding a chelating acid. Using a ferrous sulfate solution `simultaneously adjusts aquifer pH and adds the iron catalyst needed for Fenton's Reagent.

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  • Due to their low aqueous solubilities, the PCBs and PAHs lay on the surface of soils and waters. PCBs and PAHs adsorb strongly to the organic fraction of soils (Girvin & Scott, 1997; Hiller et al., 2011). Soils contaminated with PCBs and PAHs are transported directly or indirectly by rivers to the water reservoir and are subsequently converted into the bed sediments. Therefore, soils could be considered as the primary sinks for these organic contaminants. PCBs and PAHs are persistent in the environment, resistant to degradation process, and accumulate in food chain.

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  • In case of the control period (1961-1990), the initial and the lateral boundary conditions for the regional model are taken from (i) the ERA-40 reanalysis database (Uppala et al., 2005) using 1° horizontal resolution, compiled by the European Centre for Medium-range Weather Forecasts (ECMWF), and (ii) the HadCM3 ocean-atmosphere coupled GCM using ~150 km as a horizontal resolution. For the validation of the PRECIS results CRU TS 1.2 (Mitchell & Jones, 2005) datasets were used.

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  • In this, the second volume of the two-volume review of carbonates in continental settings, we continue our survey of the important aspects of their formation and utilisation.Whereas the first volume emphasised the formation of carbonate sediments, covering the depositional settings, facies and sedimentological processes; this second volume examines the geochemistry, diagenesis, sequence stratigraphy of these deposits, along with some of the practical applications. The geochemistry of continental carbonates is discussed in depth in Chapter 1.

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  • The system of three-dimensional hydrodynamic-environmental models could simulate full advection and dispersion processes of the dissolved and particulate matter as suspended sediment and all oil phases in the realistic marine conditions. The hydrodynamic model provides temperature, salinity and current structure and water level. These variables will be used in the environmental model simulating the advection and diffusion processes for suspended matter concentration, bottom sediment thickness and all oil spill phases in the water and bottom sediment.

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  • After its emission or secondary formation, the length of time airborne matter will remain suspended in the air will depend upon its density, shape and size and meteorological conditions. Suspended particles are deposited by dry deposition, either by sedimentation and gravitational settling or impaction due to atmospheric turbulence and diffusion. This latter process is characteristic of particles which undergo Brownian movement and sizes below 0.1µm.

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  • The Dien Bien basin in the Northwest of Vietnam is the largest one of the pull-apart basins related to the Dien Bien - Lai Chau fault zone. This basin, orientated from the north to the south, is 21km long, 6-8km wide and rhomboidal in shape. The process of forming this basin is related closely to the activities of the Dien Bien - Lai Chau fault zone in Neotectonic time. On analyzing information concerning the kinematics of the Dien Bien - Lai Chau fault zone, the geological structure and the sediments of the basin, we suppose that the Dien...

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  • After some further kilometres, sodium begins to increase by ion exchange at the expense of calcium, producing a natural softening of the water. Eventually, the available calcium in the water is exhausted, but sodium continues to increase to a level greater than could be achieved purely by cation exchange. As chloride also begins to increase, this marks the point at which recharging water moving slowly down through the aquifer mixes with much older saline water present in the sediments (Figure 4.1).

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  • Mercury released through sewage plants and storm sewers often contaminates the sediments of lakes and rivers on a local scale. However, most of the human-generated mercury that enters the aquatic system is deposited through the atmosphere in rain, snow or attached to small dust particles. Mercury also enters lakes directly from natural geologic sources. In lakes that have been created by hydro dams, very high levels of mercury are often found as a result of natural bacterial processes that become greatly accelerated by the flooding of land and decomposition of vegetation.

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  • In many years, changing of shoreline has caused a lot of difficulties for the sustainable development of socio-economics in the coastal zone of the Red River delta. Here, in after the Flandrian transgression, accretion process of expanding delta has continuously deve1oped. The eroded sections of shoreline appeared at the beginning of the Twentieth century (1905). The most intensive segment is in Hai Hau district. The Erosion re1ated mainly to the lack of sediment caused by exogenous and human activities. Affect of endogenous process to erosion is very weak.

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