scholarly journals Time and angle spreads due to scattering by bottom roughness and sediment volume inhomogeneity

1995 ◽  
Vol 98 (5) ◽  
pp. 2910-2911
Author(s):  
Darrell R. Jackson ◽  
Kevin L. Williams
Keyword(s):  
Sediment Volume ◽  
Volume Inhomogeneity

Operation intensification methods of aggressive industrial sewage neutralization facilities

2020 ◽  
Vol 76 (11) ◽  
pp. 1149-1153
Author(s):  
N. S. Tsarev ◽  
V. I. Aksenov ◽  
I. I. Nichkova
Keyword(s):  
Cold Water ◽  
Specific Productivity ◽  
Technological Properties ◽  
Technological Parameters ◽  
Preliminary Heating ◽  
Sediment Treatment ◽  
Circulating Water ◽  
Equipment Operation ◽  
Sediment Volume ◽  
Industrial Sewage

To neutralize the waste pickling solutions and rinsing water, resulting from cleaning metal products s surface of rust by acids solutions, lime is used. Being cheap, this method of sewage neutralization has considerable drawbacks. Forming in the technological pipes strong gypsum depositions and low specific productivity of the equipment for sediment dewatering are most significant of them. Characteristic of aggressive industrial sewage, formed at pickling of ferrous metals presented. Methods of elimination of drawbacks of industrial sewage neutralization by lime considered, including stabilization of neutralized industrial sewage and control of properties of the sediment formed. It was noted, that stability of the circulating water can be provided by accelerating of crystallization of the forming gypsum sediments by introducing in it fine priming powder and heating the neutralized water up to 65-70 °С followed by thermal softening of a part of circulating water, removed out of the circulating system. It was shown, that the heating of the water and the ongoing changes of the composition and properties of the sediment result in decrease of filtration resistance 2-3 folds, increase of deposition speed 3-4 folds and decrease the sediment volume 1.5-2 folds comparing with lime neutralization in cold water. Calculated dozes of lime at the heating were taken the same as at the regular lime neutralization. Elimination of the circulating water oversaturation by bi-water gypsum can be reached also by addition into the water of powder-like gypsum pulp - priming powder for microcrystals of the gypsum, followed by aeration during 30-40 min. This method was tested under industrial conditions. Technological properties of the forming sediment can be improved by sediment treatment by flocculants and preliminary heating of the neutralized water up to 65-70 °С. Control of technological properties of the sediment is done by addition of flocculants and heating of the neutralized water. Recommendations for improving operation of the neutralization facilities presented with indicating particular technological parameters of the equipment operation for sewage and sediment treatment. 

scholarly journals Topset-to-forest rollover trajectories as reliable predictors of sediment-volume partitioning into deep-lake areas

2021 ◽  
Author(s):  
Xian-Zheng Zhao ◽  
Cheng-Lin Gong ◽  
Li-Hong Zhou ◽  
Dong-Wei Li ◽  
Xiu-Gang Pu ◽  
...  
Keyword(s):  
Bohai Bay ◽  
Deep Lake ◽  
Bohai Bay Basin ◽  
Widespread Occurrence ◽  
Sediment Volume ◽  
Terrestrial Sediments ◽  
Qikou Sag ◽  
Sand Budget ◽  
Stacking Patterns

AbstractTopset-to-forest rollover trajectories and their relation to sediment- and sand-budget partitioning into deep-lake areas are far from being well understood, as compared with their marine counterparts of shelf edges. Two quantitatively distinctive topset-to-forest rollover trajectories and clinothem-stacking patterns were recognized in the Oligocene Qikou Sag of the Bohai Bay Basin and are quantified in terms of trajectory angles (Tse), topset thickness (Tt), forest thickness (Tf), bottomset thickness (Tb), and clinothem-set relief (Rc). Rising topset-to-forest trajectories have positive Tse of 0.15°–0.51° (averaging 0.35°). Ranges in Tt, Tf, Tb, and Rc of their associated progradational and aggradational clinothem sets are, respectively, 32.4–58.7 m (averaging 42.7 m), 76.9–176.2 m (averaging 148.3 m), 0 m, and 167.8–320.8 m (averaging 272.9 m). Falling topset-to-forest rollover trajectories, in contrast, have negative Tse of − 0.12° to − 0.02° (averaging − 0.06°). Ranges in Tt, Tf, Tb, and Rc of their associated progradational and downstepping clinothem sets are, respectively, 0 m, 266.0–395.7 m (averaging 333.4 m), 441.1–542.5 m (averaging 464.1), and 874.9–922.6 m (averaging 892.5 m). These two topset-to-forest rollover trajectories and clinothem-stacking patterns are closely linked to two distinctive patterns of sediment- and sand-volume partitioning into deep-lake areas, which are quantified in terms of Tt, Tb, and differential sediment aggradation of topset segments and forest-to-bottomset compartments (As/Ad). Rising topset-to-forest rollover trajectories and associated progradational and aggradational clinothem sets are characterized by aggradational topsets (reported as Tt of 32.4–58.7 m), a lack of time-equivalent bottomsets, and As/Ad of 0.22–0.87 (averaging 0.33), and are fronted by mud-dominated depositional deposits, with sporadic occurrence of thinner and regionally localized forest sands. They are, therefore, inefficient at delivering terrestrial sediments or sands into deep-lake settings. Falling topset-to-forest rollover trajectories and associated progradational and downstepping clinothem sets, in contrast, are characterized by toplap, erosional terminations but aggradational bottomsets (reported as Tb of 266.0–473.4 m), and As/Ad of 0, and are fronted by sand-rich depositional deposits, with widespread occurrence of thicker and regionally extensive time-equivalent deep-lake bottomset sands. They are, thus, efficient at delivering terrestrial sediments or sands into deep-lake settings. Topset-to-forest rollover trajectories and associated clinothem-stacking patterns are thus reliable predictors of sediment- and sand-volume partitioning into deep-lake areas, assisting greatly in developing a more dynamic stratigraphy.

scholarly journals CATCHMENT AREA EROSION STUDY IN ESTIMATION OF RESERVOIR CAPACITY AT THE END OF LIFE EXPECTANCY (CASE STUDY : GONDANG RESERVOIR, KARANGANYAR)

2020 ◽  
Vol 11 (1) ◽  
pp. 15-24
Author(s):  
Dhanang Samatha Putra
Keyword(s):  
Life Expectancy ◽  
Distribution Pattern ◽  
Central Java ◽  
Sediment Volume ◽  
Area Reduction ◽  
Dam Management ◽  
Reduction Methods ◽  
Dead Storage ◽  
Effective Life

Gondang Reservoir is one of The National Strategic Projects. Located in Karanganyar Regency, Central Java Province, Gondang Reservoir has 2.08 Mm3 flood storage, 5.03 Mm3 effective storage, 2.03 Mm3 dead storage and 30 years lifetime. In the dam management, one of the problems that often occurs is sedimentation. To overcome this problem, we need to know the sedimentation rate and distribution pattern of Gondang Reservoir for optimalizing the reservoir management. To predict the distribution pattern of the reservoir we use Empirical Area Reduction Methods. The findings of the study show that the sediment volume of the reservoir throughout its effective life is 2,79 Mm3, the new zero elevation is +496 m, there is no remaining dead storage and the remaining effective storage is 2.2 Mm3. This indicates that theoretically the reservoir will work well up to its life expectancy. Dam sedimentation management with structural or non structural must be planned especially at effective storage. Dam sedimentation management at effective storage is very important in order to maintain Gondang Reservoir benefits.

scholarly journals Sediment Profile Imaging: Laboratory Study Into the Sediment Smearing Effect of a Penetrating Plate

2021 ◽  
Vol 8 ◽  
Author(s):  
Annabell Moser ◽  
Iain Pheasant ◽  
William N. MacPherson ◽  
Bhavani E. Narayanaswamy ◽  
Andrew K. Sweetman
Keyword(s):  
Flat Plate ◽  
Oil And Gas ◽  
Anthropogenic Impacts ◽  
Fine Sand ◽  
Sediment Type ◽  
Particle Displacement ◽  
Fish Farms ◽  
Sediment Volume ◽  
The Mean ◽  
Sand Sediments

Sediment profiling imaging (SPI) is a versatile and widely used method to visually assess the quality of seafloor habitats (e.g., around fish farms and oil and gas rigs) and has been developed and used by both academics and consultancy companies over the last 50 years. Previous research has shown that inserting the flat viewport of an SPI camera into the sediment can have an impact on particle displacement pushing oxygenated surface sediments to deeper sediment depths and making anthropogenically-disturbed sediment appear healthier than they may actually be. To investigate the particle displacement that occurs when a flat plate is inserted into seafloor sediments, a testing device, termed the SPI purpose-built sediment chamber (SPI-PUSH) was designed and used in a series of experiments to quantify smearing where luminophores were used to demonstrate the extent of particle displacement caused by a flat plate being pushed into the sediment. Here, we show that the plate of the SPI-PUSH caused significant smearing, which varied with sediment type and the luminophore grain size. The mean particle smearing measured directly behind the inserted plate was 2.9 ± 1.5 cm for mud sediments with sand-like luminophores, 4.3 ± 2.5 cm for fine sand sediments with sand-like luminophores and 1.9 ± 1.1 cm for medium sand sediments with mud-like luminophores. When the mean depth of particle smearing was averaged over a larger sediment volume (11 cm3) next to the inserted plate, substantial differences were seen between the plate-insertion experiments and controls highlighting the potential extent of smearing artefacts that may be produced when a SPI camera penetrates the seafloor. This experimental data shows that future studies using the SPI camera, or any other periscope-like device (e.g., planar optodes) need to acknowledge that smearing may be significant. Furthermore, it highlights that a correction factor may need to be applied to these data (e.g., the depth of apparent redox potential discontinuity layer) to correctly interpret SPI camera images and better determine the effect of anthropogenic impacts on seafloor habitats.

scholarly journals NUMERICAL SIMULATIONS OF RIDGE ACCRETION AND ONSHORE MIGRATION BASED ON FIELD DATA FROM A STEEP MESO-TIDAL ENGINEERED BEACH

2018 ◽  
pp. 1
Author(s):  
Youn Kyung Song ◽  
Jens Figlus ◽  
Patricia Chardon-Maldonado ◽  
Jack A. Puleo
Keyword(s):  
Field Experiment ◽  
Numerical Simulations ◽  
Field Data ◽  
Storm Event ◽  
Swash Zone ◽  
Field Campaign ◽  
Sediment Volume ◽  
Rapid Formation ◽  
Offshore Wave ◽  
In The Beginning

Previously, the accretion of a slip-faced ridge and runnel (RR) system was observed during a 3-week field experiment on a steep meso-tidal engineered beach at South Bethany Beach, Delaware. Detailed measurements of wading depth beach profiles and nearbed flow velocities were obtained in the inner surf and swash zones along with offshore wave and current records. In the beginning of this 3-week field campaign on February 13, 2014 a Nor’easter eroded significant portions of the inner beach during this 1-day long storm event. Immediately after the storm during the less energetic conditions, the rapid formation of a pronounced RR system was observed which then continuously evolved over the duration of 2-week poststorm recovery periods. In the last day of the field campaign, 85% of the sediment volume eroded during the storm was recovered in the swash zone. However, no more evolution of the RR system toward the runnel infilling or landward migration was observed.

scholarly journals Acoustic characterization of seafloor habitats on the western continental shelf of India

2007 ◽  
Vol 64 (3) ◽  
pp. 551-558 ◽  
Author(s):  
Bishwajit Chakraborty ◽  
Vasudev Mahale ◽  
Gajanan Navelkar ◽  
B. Ramalingeswara Rao ◽  
R. G. Prabhudesai ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Dual Frequency ◽  
Scattering Process ◽  
Backscatter Signal ◽  
Sediment Volume ◽  
Interface Scattering ◽  
Acoustic Characterization ◽  
Power Law Exponent ◽  
Different Grain Size

Abstract Chakraborty, B., Mahale, V., Navelkar, G., Rao, B. R., Prabhudesai, R. G., Ingole, B., and Janakirinam, G. 2007. Acoustic characterization of seafloor habitats on the western continental shelf of India. – ICES Journal of Marine Science, 64: 551–558. This is a study of the interaction effects of the dual-frequency (210 and 33 kHz) backscatter signal with seafloor sediment and benthic biota along a transect in water 27–83 m deep offshore of the Goa region of India's central west coast. Estimation of the power-law exponent using seafloor topographic data provided equivalent values even when using dual high-frequency systems for different grain-size sediments. Backscatter signals corrected from system-related gain, etc., reveal better correlations with sedimentary and benthic parameters than the estimated coherence parameters (using echo peaks). Statistically, correlations are significant for the 210 kHz backscatter signal with sand and calcium carbonate (CaCO3) sediment content. Also, correlations are higher for macrobenthic biomass (wet weight) and population density with a 210 kHz backscatter strength, emphasizing the dominant seawater–seafloor interface scattering process. For 33 kHz backscatter strength, the absence of such correlations indicates a different scattering process, i.e. dominant sediment volume scattering attributable to the comparatively lower signal attenuation. Additionally, to validate the results, the backscatter signals from other locations in the vicinity of this transect were considered.

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