Sedimentation Rate In Area Research Articles

Exploring Thermal Barrier and Sedimentation Simulation for Enhanced Performance in Grati Combined Cycle Power Plant

PLTGU is a power generation facility that concurrently utilizes both steam and gas power plant technologies. It necessitates a cooling system to operate efficiently throughout its entire lifespan. If PLTGU Grati plans to increase its power capacity, there is a concern that the water discharged from the Water Outlet channel might not cool down sufficiently before re-entering the Water Intake channel. Additionally, sedimentation in the sea water uptake is causing siltation. Hence, this study focuses on the jetty extension project to address sedimentation and hot water spreading issues in PLTGU Grati. The numerical modeling analysis, conducted using the Delft3D software, indicates that in the case of power addition, Alternative Model 1 can reduce the highest temperature compared to the existing condition by 0.655°C. Similarly, Alternative Model 2 reduces the highest temperature by 0.090°C. Moreover, with power addition, sedimentation rate in Area 1 increases by 261.43 m3/month in Alternative Model 1, while in Alternative Model 2, it decreases by 969.47 m3/month compared to the existing condition. Considering the ability of Alternative Model 2 to effectively reduce the temperature in the inlet canals by 0.090°C, it provides the best solution to contain the spread of hot water in the PLTGU Grati area. Currently, PLTGU Grati employs a Cutter Suction Dredger (CSD) to periodically dredge the water inlet channel. Therefore, Alternative Model 2 is recommended as the optimal choice among the alternatives. Henceforth, detailed studies related to current patterns and sedimentation rates are presented comprehensively in this paper.

Study on Vertical Profile of 210Pb and Sedimentation Rate at Pantai Remis Coastal Area and Kuala Selangor Estuary

Two sediment cores in Kuala Selangor estuary and Pantai Remis coastal area were obtained using gravity corer and then were analyzed using Alpha Spectrometry System. In order to estimate the sedimentation rate in the area, 210Pb dating technique and Constant Rate & Supply (CRS) model were used. From the study, the vertical profile of 210Pb shows a decreasing trend with depth and finally achieving a constant level. Based on the vertical profile of 210Pb, activity of excess 210Pb was obtained and was used to determine the sedimentation rate in the study area. Pantai Remis coastal area shows high sedimentation rate than Kuala Selangor estuary which may due to high sediment input in the area. Besides, the differences in sedimentation rate might be attributed to highly variable sedimentary and hydrodynamic conditions in the estuary and coastal area.

LATE QUATERNARY TERRIGENOUS DEPOSITS FROM CORE P31 ON THE CHUKCHI PLATEAU OF WESTERN ARCTIC OCEAN AND THEIR PALEOCEANOGRAPHIC AND PALEOCLIMATIC IMPLICATIONS

Terrigenous components in the core P31 from the Chukchi Plateau,western Arctic Ocean,have been investigated to reconstruct source regions and related climate changes.Together with AMS14C dating,the stratigraphy of the core was established by a combination of variations of lithological features,color cycles,XRF scanned elements content,foraminifera abundance,Ice Rafted Detritus(IRD,250 μm and 154 μm)events and grain size components.The Core P31 extends back to the Marine Isotope Stage(MIS) 3.A total of five IRD events were distinguished during the late MIS 1,MIS 2 and early to mid MIS 3.These IRD,transported by sea ice and icebergs,and brought to the Chukchi Plateau,by the Beaufort Gyre,might be exported from the M'Clure Strait Ice Stream,Canadian Arctic Archipelago.They are indicators of the collapse events of North American Ice Sheet(NAIS) and the evolutionary history of the Beaufort Gyre since MIS 3.Grain size components changes show that the sand components,which correspond to the high IRD size fraction,might be transported by icebergs;but the silt components might be mainly transported by sea ice,and the clay component was probably mainly carried by the Beaufort Gyre.The variation of two sensitive components(5-13 μm and 110-176 μm) present clear symmetric distribution,the coarser component corresponds to the IRD,and the finer may indicate the source region and the influence of deposition.During MIS 3,MIS 2 and MIS 1,the sedimentation rates of core P31 are 2.2 cm/ka,0.16 cm/ka and 1.6 cm/ka,respectively.The average sedimentation rate is about 1.2 cm/ka.The overall picture of the western Arctic Ocean shows high sedimentation rates in the ice edge,and low sedimentation rates in areas with permanent sea ice cover.High sedimentation rates occur in areas of shallow water depth,and close to the terrigenous source regions,and low sedimentation rates in the high latitude area of Mendeleev-alpha ridge and Canada Basin area.

Cretaceous synsedimentary tectonics in the Atlas system of Central Morocco

Cretaceous sediments in Central Morocco were deposited in various depositional environments and comprise an undetermined Lower Cretaceous base up to Maastrichtian. The sedimentary columns show a similar facies evolution. Basal unconformities, conglomeratic layers and significant differences in thicknesses reflect pre- and synsedimentary vertical tectonic movements. These tectonic movements took place along large NE/SW striking fault systems, one of the major features of the present tectonic framework. Permanent displacement of the subsidince maxima in time and space indicate the development of small tectonic blocks which were tilted and/or compressed between the fault zones. High sedimentation rates in areas of strong subsidence, however, prevented the evolution of intraplatformbasins. Although tectonic influence was important, eustatic sea level changes ruled the whole sedimentary regime.

Petroleum hydrocarbons in sediments of Southampton water estuary

The sediments of Southampton Water were analysed for petroleum hydrocarbons to determine the fate of petrochemical refinery waste in the estuary. Much of the petroleum hydrocarbons appears to be removed by adsorption onto estuarine sediments close to source. Surface sediment concentrations range from 3·1mg/g dry weight near a refinery to 0·5 mg/g dry weight at locations distant from the refinery. The absence of any change with depth in total hydrocarbon concentrations from some sediment cores and the presence of distinct ‘oil’ horizons in others suggests that mixing of sediments in the area is very random. Sedimentation rates in areas where a distinct oil horizon was observed ranged from 1 to 3cm a year.

Late Quaternary pelagic sedimentation on the southern Calabrian Ridge and western Mediterranean Ridge, eastern Mediterranean

Cores from plateaus, lying some 150–200 m above the basin floors in areas of strong vertical relief visited during the Cobblestone Project, consist entirely of pelagic marls with sapropels and tephras as minor lithologies. All the plateau cores were correlated by means of isochronous lithologies and biostratigraphically calibrated. A core from Area 3 (No. 29) and two cores from Area 4 (No. 45 and 6) were selected as reference sections and studied quantitatively in terms of grain sizes, carbonate content and microfossil content. Faunal curves based on selected species of planktonic foraminifers correlate between the three cores, which extend back in time to approximately 185 000 yr for Area 4 and to 430 000 yr for Area 3. Winnowing resulted in a reduced sedimentation rate in Area 3, in unusually high percentages of the coarser sediment fraction and in extended hiatuses at the top of the cores. The highest temperature in surficial waters as indicated by the foraminiferal faunas is recorded in all three references sections at the base of an interval correlative with isotopic stage 5e (∼ 125 000 yr B.P.), within sapropel S-5. Clay mineralogy indicates basically uniform conditions in the two areas, with the exception that smectite is more abundant in the Calabrian Ridge, which is closer to its source area (Sicily, Sicily Channel). Carbonates include calcite, magnesian calcite and some dolomite. Sapropels, sedimentary expression of stagnation, represent up to 25% of the sedimentary column in an interval encompassing isotopic stage 5 through 7. The average organic carbon content in analysed sapropels is 3.1%, versus 0.29% in normal pelagic sediments. Sapropels S-6 and S-8 are consistently accompanied by a foraminiferal fauna that is indicative of low-salinity cool surficial waters, whereas sapropels S-1, S-5 and S-7 occur in coincidence with the warmest peaks of the climatic faunal curve. Average sedimentation rate is 3.2 cm/1000 yr for Core 29; 5.5 cm/1000 yr for Core 45. Sedimentation rates calculated for basin cores are five to ten times higher. Sedimentation rates of sapropels and tephras are independent from regional sedimentation rates. Hiatuses in plateau cores correlate with debris flows in base-of-slope cores, both occurring during times of enhanced bottom circulation and submarine erosion related to low stands of sea level in cold periods.

Wear and compatibility behavior of liquidmetal bearing materials. (66-WA/Lub-3) : M. J. Wallace, pp. 466–472; 4 figs., 9 tables, 12 refs.

Cores from plateaus, lying some 150–200 m above the basin floors in areas of strong vertical relief visited during the Cobblestone Project, consist entirely of pelagic marls with sapropels and tephras as minor lithologies. All the plateau cores were correlated by means of isochronous lithologies and biostratigraphically calibrated. A core from Area 3 (No. 29) and two cores from Area 4 (No. 45 and 6) were selected as reference sections and studied quantitatively in terms of grain sizes, carbonate content and microfossil content.Faunal curves based on selected species of planktonic foraminifers correlate between the three cores, which extend back in time to approximately 185 000 yr for Area 4 and to 430 000 yr for Area 3. Winnowing resulted in a reduced sedimentation rate in Area 3, in unusually high percentages of the coarser sediment fraction and in extended hiatuses at the top of the cores.The highest temperature in surficial waters as indicated by the foraminiferal faunas is recorded in all three references sections at the base of an interval correlative with isotopic stage 5e (∼ 125 000 yr B.P.), within sapropel S-5.Clay mineralogy indicates basically uniform conditions in the two areas, with the exception that smectite is more abundant in the Calabrian Ridge, which is closer to its source area (Sicily, Sicily Channel). Carbonates include calcite, magnesian calcite and some dolomite.Sapropels, sedimentary expression of stagnation, represent up to 25% of the sedimentary column in an interval encompassing isotopic stage 5 through 7. The average organic carbon content in analysed sapropels is 3.1%, versus 0.29% in normal pelagic sediments. Sapropels S-6 and S-8 are consistently accompanied by a foraminiferal fauna that is indicative of low-salinity cool surficial waters, whereas sapropels S-1, S-5 and S-7 occur in coincidence with the warmest peaks of the climatic faunal curve.Average sedimentation rate is 3.2 cm/1000 yr for Core 29; 5.5 cm/1000 yr for Core 45. Sedimentation rates calculated for basin cores are five to ten times higher. Sedimentation rates of sapropels and tephras are independent from regional sedimentation rates.Hiatuses in plateau cores correlate with debris flows in base-of-slope cores, both occurring during times of enhanced bottom circulation and submarine erosion related to low stands of sea level in cold periods.