Sediment Height Research Articles

Comprehend Analysis of Surface and Subsurface Sediment Distribution Using Underwater Acoustic Instruments

Abstract Ports play an important role in shipping and transporting while its fundamental challenge is sedimentation that occurs continuously at a location. A management system is required to respond to this siltation problem by dredging the underwater sediments parallel with Sustainable Development Goal 11 about sustainable cities and communities. Therefore, analyzing the area’s sediment types and distribution is necessary, especially using acoustic instruments. In this research, the dredging plan shows the relative depth distribution is around 4 to 18 meters with deep sloping topography on the north side. Furthermore, the overall result of the backscatter value of the multibeam echosounder ranges from −45.86 dB to −55.73 dB. According to the Angular Response Analysis, the sediment type of the seabed surface is clay with depths ranging up to 5.40 meters. The result of the sub-bottom profiler processing discovers step or bowl-like features where the curvature seems to have an unequal height. It considers the difference in sediment height around the area while the intensity is relatively low. Through acoustic processing analysis, it informs that the total area of 643872 m2 needs to be dredged with an estimated dredging volume of around 2181105 m3 both in surface and subsurface areas. The qualitative analysis of Multibeam Echosounder, and Sub Bottom Profiler data shows that the acoustic instrument’s products are accurate with validation data in the field.

Numerical simulation of the effect of downstream material on scouring-sediment profile of combined spillway-gate

ABSTRACT Overflow structures are among the most important hydraulic structures used for measuring flow, controlling floods in reservoirs, and regulating water levels in open channels. Alternative options, such as combined structures like spillway-gates, are preferred due to their compatibility with natural and ecological needs. This study investigates the impact of different soil gradations downstream on the scouring profile of combined spillway-gate structures. Scouring and sedimentation downstream of the spillway-gate were examined under various particle sizes of 0.0008, 0.001, and 0.0014 m, with a constant density in both free and submerged flow conditions using the FLOW-3D software. In this study, the k-ε, k-ω, LES, and RNG turbulence models were evaluated, and the RNG turbulence model was selected among that group. In free flow conditions, the highest sediment deposition occurred with the smallest particle diameter. For larger particle diameters, the void spaces between the particles reduce friction and increase the movement threshold, leading to increased scouring and decreased sediment height. In submerged flow conditions, the changes in scouring for different particle sizes were minor, with results being closely aligned. In submerged flow conditions, increasing the particle diameter resulted in a decrease in sediment deposition in the post-scouring area.

Sedimentation Analysis at Cariang Weir in Sumedang District using Mike 21 Software

Sedimentation is the deposition of material carried by water media. The occurrence of sedimentation disrupts river flow, leading to increased susceptibility to flooding and drought during dry seasons. The impact of sedimentation causes riverbed siltation, reducing the river's capacity from its natural state. The Cariang Dam, located in Ujung Jaya Village, Ujung Jaya District, Sumedang Regency, is experiencing sedimentation issues. This has resulted in siltation and a decrease in the river's capacity at the dam site. In light of these issues, the researcher is interested in analyzing sedimentation at the Cariang Dam area. This analysis aims to determine the volume and height of sedimentation occurring annually. Based on the analysis conducted, the sedimentation height per day is found to be 0.7 centimeters, amounting to 23 centimeters per month and 276 centimeters annually.

A front-fixing numerical method for a fluvio-deltaic sedimentation process with thespace fractional derivative and variable sediment flux

This paper centers around a space-fractional mathematical model for a fluvio-deltaic sedimentation process which involves a space-fractional derivative (Caputo derivative) and time dependent variable sediment flux to investigates the movement of shoreline in a sedimentary ocean basin. This model is a specific case of a basic shoreline model and analogous to a Stefan problem. The numerical solution to the problem is acquired by employing a front-fixing explicit finite difference method. The consistency, stability and convergence of the numerical scheme are theoretically analyzed. The effects of variable sediment flux on the movement of shoreline position and the height of sediments are also assessed for different cases.

Mechanical Behavior of Sediment-Type High-Impurity Salt Cavern Gas Storage during Long-Term Operation

With the development of salt cavern gas storage technology, the construction of large-scale salt cavern gas storage using sediment voids is expected to solve the problems of low effective volume formation rate and poor construction economy of high-impurity salt mines. At present, there are few studies on the long-term operational mechanical behavior of salt cavern gas storage under the influence of sediment accumulation. The present paper studies the influence of sediment height, particle gradation, and operating pressure on the stability of salt caverns by constructing a coupling model of sediment particle discontinuous medium and surrounding rock continuous medium. The continuous–discontinuous coupling algorithm is suitable for analyzing the influence of sediment height and particle gradation on the creep shrinkage of salt caverns. The increase in sediment height slows down the creep shrinkage of the cavern bottom, which strengthens the restraining effect on the surrounding rock of the cavern. As a result, the position of the maximum displacement of the surrounding rock moves to the upper part of the cavern. The sediment particle gradation has little effect on the cavern volume shrinkage rate. The greater the coarse particle content, the smaller the cavern volume shrinkage rate. The greater the operating pressure, the more conducive to maintaining the stability of the cavern. This situation slows down the upward movement of the sediment accumulation and increases the gas storage space in the upper part of the cavern. The obtained results can provide a reference for evaluating the long-term operational stability of sediment-type high-impurity salt cavern gas storage.

Effect of incubation conditions of cellulase hydrolysis on mechanical pulp fibre morphology

The mechanical pulp industry is diversifying through the manufacture of high-value paper products, such as microfibrillated cellulose. However, the development of fibre quality is still energy-intensive. Enzymatic hydrolysis is hypothesized to promote fibre cutting, greater fibrillation, and reduce refining energy costs. Despite potential benefits, there is little understanding of the mechanisms behind fibre development during enzymatic hydrolysis of mechanical pulp. This work investigates how incubation pH and temperature during enzymatic hydrolysis impact the refining of mechanical pulp short fibres. Incubation with endoglucanase at pH 5 and 60 °C increased fibre cutting by approximately 20 %. Fibrillation was negatively affected at this condition, resulting in increased slim fines formation with refining. Incubation at pH 8 and 80 °C promoted >15 % reduction in fibre length, despite such conditions being associated with low enzyme activity. The pH variation modified the sedimentation height of the fibres and the conductivity of suspensions, indicating a change in fibre surface charge. Fibre morphology changes were induced by enzyme hydrolysis conducted at conditions representative of the full range of pH and temperature observed in mechanical pulp mills.

An automated platform for measuring infant formula powder rehydration quality using a collaborative robot integrated with computer vision

Current methods used for testing the rehydration quality of infant formula (IF) are mainly subjective. For a better understanding of rehydration, objective measurements are required. A computer vision (CV) system was synchronized with a collaborative robot (cobot) to automatically estimate foam height, sediment height, and the number of white particles after IF powder rehydration. Two different robotic agitations were used to prepare the mixtures in a commercially available baby bottle. To evaluate the platform, twenty-four stage-1 IF powders were rehydrated. Cobot-captured images were processed by CV algorithms and independently rated by eight participants. The participants' and platform's estimates of foam height, sediment height, and white particles score, respectively, showed agreements of 2.1 mm, 3.4 mm, and 1.7 scores, and correlation coefficients of 0.82, 0.77, and 0.68. The results show that the platform has the potential to enable objective rehydration tests and to monitor changes in visible foam and sediment over time.

Modeling the impact of the temperature profile on the sedimentation process for shear thinning suspensions in the annulus of oil well

The particle settling phenomena were broadly studied in the literature experimentally and numerically. To the best of our knowledge, previous works do not consider the temperature effect on the suspension rheology and, consequently, the influence over the settling velocity. Motivated by the problem of the sedimentation in confined drilling fluids exposed to a geothermal temperature gradient, this work proposed a continuum model for the sedimentation process of weighting agents in non-Newtonian suspensions based on the Mixture Theory. A temperature-dependent correction for the suspension consistency index was proposed and the results were discussed for different temperature profile cases, including uniform temperature profile, linear and geothermal profiles. Numerical simulations were performed, using the Finite Volume technique. Results for the solids concentration along the column for up to five years were discussed as well as the solids concentration evolution for selected points along the column. The results showed that the temperature gradient significantly impacts the settling velocity and the evolution of sedimentation regions. The main affected zones were the free settling and the sediment zones, which can alter directly parameters of interest for applications in oil wells, such as the height of sediment.

Deep convolutional neural networks with Bee Collecting Pollen Algorithm (BCPA)-based landslide data balancing and spatial prediction

Predicting the landslide-prone area is critical for various applications, including emergency response, land planning, and disaster mitigation. There needs to be a thorough landslide inventory in current studies and appropriate sampling uncertainty issues. Landslide risk mapping has expanded significantly as machine learning techniques have developed. However, one of the primary issues in Landslide Prediction is data imbalance (DI). This is problematic since it is challenging or expensive to generate an accurate inventory map of landslides based on previous data. This study proposes a novel landslide prediction method using Generative Adversarial Networks (GAN) for generating the synthetic data, Synthetic Minority Oversampling Technique (SMOTE) for overcoming the data imbalance problem, and Bee Collecting Pollen Algorithm (BCPA) for feature extraction. Combining 184 landslides and ten criteria, including topographic wetness index (TWI), aspect, distance from the road, total curvature, sediment transport index (STI), height, slope, stream, lithology, and slope length, a geographical database was produced. The data was generated using GAN, a Deep Convolutional Neural Network (DCNN) technique to populate the dataset. The proposed DCNN-BCPA approach findings were merged with current machine learning methods such as Random Forests (RF), Artificial Neural Networks (ANN), k-Nearest Neighbours (k-NN), Decision Trees (DT), Support Vector Machine (SVM), logistic regression (LR). The model’s accuracy, precision, recall, f-score, and RMSE were measured using the following metrics: 92.675%, 96.298%, 90.536%, 96.637%, and 45.623%. This study suggests that harmonizing landslide data may have a substantial impact on the predictive capabilities of machine learning models.

Influence of the frequency on undulatory swimming speed in granular media.

Sand is a highly dissipative system, where the local spatial arrangements and densities depend strongly on the applied forces, resulting in fluid-like or solid-like behaviour. This makes sand swimming challenging and intriguing, raising questions about the nature of the motion and how to optimize the design of artificial swimmers able to swim in sand. Recent experiments suggest that lateral undulatory motion enables efficient locomotion, with a non-monotonic dependence of the swimming speed on the undulatory frequency and the height of the sediment bed. Here, we propose a 2D granular model, where the effect of the sediment height is modeled by an effective frictional force with the substrate. We show that the optimal frequency coincides with the second vibrational mode of the swimmer and explain the underlying mechanism through a characterization of the rheology of the medium. Potential implications in the design of artificial swimmers are discussed.

The influence of ultra-probe sonication and polyvinylpyrrolidone on dispersion stability and photocatalytic activity of Ag-TiO2 nanoparticles

The growing use of silver-modified titanium dioxide nanoparticles (Ag-TiO2 NPs) raises environmental concerns. In industrial applications, ultrasonication and surfactant addition are widely employed to improve the efficiency of small amounts of Ag-TiO2 for better dispersion stability. Understanding the stability and dispersion of Ag-TiO2 NPs is crucial. The dispersion stability of Ag-TiO2 NPs is greatly influenced by ultra-probe sonication and polyvinylpyrrolidone (PVP). Ag-TiO2 NP concentrations from 0.1% to 10.0% m/v and PVP concentrations from 0.006% to 0.400% m/v were both used in this study. The effect of ultra-probe sonication presented a high sedimentation height ratio and turbidity below the settling time of 90 min for 0.1%Ag-TiO2 without PVP. A sonication amplitude of 35% and a sonication time of 15 and 30 min showed optimal conditions for good dispersion for 0.1% and 1.0% Ag-TiO2 whereas a sonication amplitude of 20% for 70 s and 140 s was suited for 5.0% and 10.0% Ag-TiO2, respectively. The concentration of PVP was found to be 0.04 times the concentration of Ag-TiO2 for good dispersion. Coordination bonds on the surface of Ag-TiO2 with the carbonyl group served as proof of the chemical adsorption of PVP and Ag-TiO2 NPs. The PVP-coated Ag-TiO2 NPs showed smaller particle sizes and a narrower size distribution than Ag-TiO2. The PVP-coated 1.0% Ag-TiO2 NPs provided lower methylene blue degradation ((5.06 ± 0.76) × 10−3 min−1) under visible light than those without PVP ((9.90 ± 0.74) × 10−3 min−1). These findings advance our understanding about how PVP affects dispersion and photocatalytic activity on Ag-TiO2 and suggest the potential applications as a water pollution coating material.

ПОЛУЧЕНИЕ КОМПОНЕНТОВ БИОТОПЛИВА ДЛЯ СУДОВЫХ ЭНЕРГЕТИЧЕСКИХ УСТАНОВОК

The article discusses the prospects for the use of biofuels as an alternative fuel for marine diesel engines. The
 results of the analysis of applied technologies for the production of biodiesel are presented. The expediency of
 using a hydrodynamic mixer as a device that ensures the intensity of the transesterification reaction in the
 production of biodiesel is substantiated. A technological scheme of a laboratory plant for the production of
 biodiesel has been developed. The results of laboratory studies to determine the optimal material balance of the
 transesterification reaction for the production of biodiesel in a plant equipped with a hydrodynamic mixer are
 presented. The main indicators of the interesterification reaction (viscosity, flash point, sediment height) for a
 plant equipped with a hydrodynamic mixer have been determined. The optimal mass ratio of the transesterification
 reaction has been established, which ensures the best quality indicators of the resulting biodiesel and
 allows evaluating the efficiency of the hydrodynamic mixer used in the plant. Recommendations are given on
 the ratio of vegetable oil and methanol in the production of biodiesel. The best oil/methanol ratio, in terms of
 biodiesel yield and quality, is 7.5:1. The use of traditional petroleum fuels mixed with biodiesel can be seen as
 an effective way to reduce air pollution from ships and ensure compliance with the rules of the International
 Maritime Organization

Investigation of the reduction of sediment deposition and river flow resistance around dimpled surface piers.

To reduce sediment accumulation in urban rivers due to the influence of cylindrical bridge piers on river flow resistance, the hydraulic performances of cylindrical piers were investigated using the computational fluid dynamics software FLOW 3D and compared with experimental data. The method included scouring and sedimentation analysis of piers and showed high accuracy at predicting experimental data. A dimpled surface pier was used as the model, and a series of simulations were conducted to evaluate its hydraulic performance. The results showed that scouring extents of a dimpled surface pier are larger than those of a cylindrical pier under different working conditions. This difference helped reducing sludge sedimentation at the bottom of the river in the former. The ratio of the maximum sedimentation height to the pier diameter ([Formula: see text]), ratio of the sedimentation area, and cross-sectional area of the dimpled surface pier ([Formula: see text]) are all smaller than those of a cylindrical pier at different flow velocities, indicating that dimpled surface piers have a lower silting probability. Compared with cylindrical piers, dimpled surface piers offer less interference to turbulent flow and generate a small-scale spiral flow; a lower lateral velocity is also obtained behind the dimpled surface pier, which leads to lower flow resistances and lower energy dissipation, which helps scour.

Important Role of Biogas and Secretions in the Formation of Biological Fluid Sediment under Cyanobacterial Bloom Biomass Degradation

In eutrophic shallow lakes, cyanobacterial blooms will occur frequently and then accumulate on sediments, leading to the formation of biological fluid sediment. In this study, the formation process of biological fluid sediment was investigated in microcosm experiments by monitoring the variations in gas, sediment physicochemical properties, and microorganisms during 30 days. It was found that variations in sediment height reached the maximum value on day 8 (0.53 cm) with the minimum sediment density (1.04 g cm–3). Meanwhile, the amount of carbon dioxide (CO2) produced through fermentation was larger than methane (CH4) during the initial 4 days. Then, the amount of CH4 drastically increased, resulting in the release of gas from sediments. In addition, a high amount of extracellular polymer substances (EPSs) was produced and led to sediment particle agglomeration, which benefited in maintaining the structure of biological fluid sediment. Through the microbial community analysis, it was found that the strong symbiotic structure of the microbial community in the early stage provided favorable conditions for the formation of CH4 in sediments. The results of this study can clarify the formation mechanism of biological fluid sediment and provide help for understanding the effect of biogas and secretions on the sediment properties in shallow lakes.

A numerical study of the effect of a lateral intake’s position and angle on scouring around a pier in a bend

ABSTRACT The present paper addresses the effect of placing an intake, as a diversion structure, in different positions and with various angles in a 180° bend to investigate the scour depth around a circular pier in an SSIIM2 numerical model. The simulation was conducted by placing the intake at the 75°, 90°, 115°, 135°, and 150° positions with 45°, 60°, and 90° angles. The results indicated that the greatest effect was associated with the installation of the intake with a 90° angle at the 135° position, which decreased the maximum scour depth by a considerable amount, about 70%, compared with the bend without an intake. However, the maximum scour depth occurred with the installation of the intake at the 150° position with an intake angle of 45° and increased by 20% compared to the bend without an intake. Furthermore, the maximum and minimum scour hole wall slopes around the pier in the case of the bend with an intake respectively increased by 6.24 times and decreased by 5.1 times compared to the bend without an intake at the upstream pier. The maximum sedimentation height around the pier decreased by about 40% in the bend with an intake compared to the one without an intake.

Numerical investigation of silted-up dam-break flow with different silted-up sediment heights

Abstract The silted-up sediment in the reservoir may have a significant influence on the propagation of dam-break flows. In this paper, a three-dimensional numerical simulation of the silted-up dam-break flow is carried out. In this paper, simulations of three-dimensional silted-up dam-break flow are carried out. A kind of Eulerian–Eulerian two-fluid model (TFM), coupled level set and volume of fluid (CLSVOF) methods, is presented. In order to calculate the motions of the air–water interface and the sediment simultaneously, kinetic particle theory (KPT) and computational fluid dynamics (CFD) are combined. The rheology-based constitutive equations of sediment are also considered to simulate scouring and deposition. In addition, a partial-slip boundary condition (BC) for the velocity of the sediment phase at stationary walls is implemented. The simulation results of the benchmark case demonstrate that the proposed model can effectively simulate the silted-up dam-break flow while taking into account multi-interface capturing problems. Subsequently, the simulations of the silted-up dam-break flow over dry are investigated numerically in a three-dimensional long channel. The simulated results reveal that, in the dam-break flows, the silted-up sediment height has a significant influence on wave propagation, dynamic pressure loads, sediment transport, and sediment deposition.

Experimental investigation of sediment movement as a result of homogeneous earth-fill dam overtopping break over a simplified urban area

When an earth-fill dam breaks, dam body sediment and water flow simultaneously move to downstream area causing devastation. Dam break studies in the literature have concentrated mostly on the water flow part while ignoring the sediment movement by designing the dam body as a movable metal gate. This study, however, is the first one experimentally investigating flow and sediment transport due to an earth-fill dam break by constructing the dam body from sediment. Sediment propagation as a result of homogenous earth-fill dam overtopping break was experimentally studied in a laboratory flume of 18.4 m long and 2.0 m wide, and 0.88 m in height in the Hydraulics Laboratory of Izmir Katip Celebi University, Izmir, Turkey. Downstream section right after the dam body was designed as a smooth bed and rough bed. The rough bed, resembling a simplified urban area, was created by using thirteen 10 × 10 × 10 cm sized concrete blocks. The dam body was constructed as homogenous with uniform material having D50 = 0.441 mm. The earth-fill dam body was built using the standard compression methods; each layer of sediment with a thickness of 10 cm was laid in layers, and the body was prepared with a crest width of 10 cm, a transverse base width of 200 cm, a longitudinal base width of 202 cm and height of 60 cm with upstream and downstream slopes of 1:1.6. The water level behind the dam was gradually raised until it overtopped the crest level. A pre-breach was formed at the top of the dam to trigger the break. During each dam break event, water depths were measured by three ULS-40D level meter sensors at different locations, and the final sediment bathymetry map was generated using the ULS-40D Probes at 10 × 10 cm grids. The results showed that, in both smooth and rough downstream bed cases, the dam body eventually collapsed while a great portion of it was carried away by the flood flow. The sediment spreading occurred all over the downstream area, showing significant non-uniform variation in thickness both longitudinally and transversely, especially in the simulated urban area. All the residential areas, while breaking in motion, were submerged under the muddy flow. Some blocks were almost submerged while sediment heights reached half level of some blocks at the end of the experiment. Sediment heights were higher in the urban area.

Implementation of Building with Nature (BwN) as Adaptive Concept to Prevent Coastal Erosion in Demak Regency, Central Java, Indonesia

North Java, Indonesia's Shoreline degradation has become a severe problem along its coast. The gradually vanishing of the mangrove greenbelt indicates starting of coastal erosion. To overcome that problem, the adaptive concept using Building with Nature (BwN) is expected to become a part of the solution by enhancing the natural process. Construction of permeable structures was started in 2013. Its implementation was modeled using Delft3D. A coupling between Delft3DFlow and Delft3DWave is proposed. The model is conducted in two scenarios, coastal areas without and with permeable structures. Both were simulated in wet and dry seasons. It is analyzed on three years morphological scale. 10 observation points were determined in the front and back of structures. Those are utilized as control points to check the height of sediment trapped. Accumulation of sediment trapped in wet and dry seasons, and the coverage area was a dry season without structures. By adding a permeable structure, the maximum amount of sediment trapped in the wet season reaches 1.52 m in three years of simulation. It can be concluded that permeable structures constructed along the coast can trap the sediment. The placement, length, and number of structures should be considered to produce a wider coverage area. In the future, the sustainability of this adaptive concept is expected to enhance the coastal restoration in Demak coastal area.

Stability and sedimentation characteristics of water based Al2O3 and TiO2 nanofluids

Nanofluids are regarded as promising heat transfer fluid due to their ultrafast cooling capability. However, stability analysis of nanofluids is very critical before its application in heat transfer .The present paper reports about an investigation on the stability of water-based Al2O3 and TiO2 nanofluids at ambient temperature. Nanoparticles, namely Al2O3 and TiO2 at different concentrations of 1, 0.5, 0.1, 0.05, and 0.01 wt.% respectively were directly dispersed in water without adding any dispersant and placed in a static container to observe gravitation settling. Change of sedimentation height with respect to time was measured using the sedimentation photograph capturing method. DLS (Dynamic Light Scattering) and zeta potential analysis were also executed to examine the stability of nanofluids. The results show that the visualization method, DLS and zeta potential analysis are in good correspondence to each other. Sedimentation velocity increases with an increase in nanoparticle concentration and aging. Brownian motion of nanoparticles resist the sedimentation in nanofluids. It is observed that TiO2nanofluid is more stable as compared to Al2O3 nanofluid due to its smaller particle size. Finally authors recommend smaller particle size, optimized sonication time, low nanoparticle concentration and use of surfactant to obtain better dispersion stability of nanofluids

Particle sedimentation models for a commercial lithium extraction process from brine

This work assesses and examines particle sedimentation behaviors for magnesium removal process in a commercial lithium recovery plan with the aid of a lab-scale stirred tank reactor in the presence and absence of rotational stirring. The effects of stirrer agitation rate on the sediment height and induction period were investigated in the range of 280–390 RPM. A one-dimensional unsteady-state model was utilized, capable of describing the main phenomena observed in experimental particle sedimentation tests. The model showed fair agreement with experimental results obtained for the batch-wise sedimentation at different agitation rates. Moreover, the model was further used to assess the particle sedimentation behaviors in batch-wise and continuous stirred tank reactors. A critical boundary, based on a critical Peclet number and initial solid volume fraction, was proposed to avert/decelerate particle sedimentation in both reactor configurations, which could provide operation guidelines for batch and continuous reactors.