scholarly journals ENVIRONMENTAL AND HYDRAULIC MONITORING USING CATIONIC DYES TO INVESTIGATE THE BARRIERS EFFECT ON KAOLIN DEPOSITION

2021 ◽  
Vol 25 (5) ◽  
pp. 103-112
Author(s):  
Ekram A. AL-Mafraji ◽  
◽  
Haider A. Al-Mussawy ◽  
Keyword(s):  
Water Depth ◽  
Research Methodology ◽  
Environmental Indicators ◽  
Cationic Dyes ◽  
Blue Dye ◽  
Contaminated Water ◽  
Initial Water ◽  
Horizontal Pipes ◽  
Maximum Water ◽  
Precipitate Composition

Dyes are used in hydraulic fields such as hydraulic tracking to show the flow path, monitor flow lines within a ground dam, or track the spread of contaminated water within horizontal pipes and environmental fields as environmental indicators in titrations, such as titration of precipitate composition. Some environmental experiments dispense with the dye's use because it interferes with other compounds, such as interfering with the turbidity readings even if non-reactive dyes, but the present study transformed this problem into a positive phenomenon to benefits from the dye in both fields. The research methodology includes a laboratory analysis using different parameters such as discharge of suspension, the volume of dye, and the percentage of initial water depth at maximum water depth also theoretical analysis of the previous research methodology. The experimental results show that cationic dyes' absorption (methylene blue dye, MB and crystal violet, CV) is directly proportional to the percentage of kaolin deposition in the sedimentation tank areas. Finally, MB and CV dyes are used in both fields in one trial(such as tracking flow movement, monitoring the vortices formed using baffles, and inter between the amount of kaolin precipitated in each zone the sedimentation). However, MB is the best compare to CV.

scholarly journals Detonation and Transition to Detonation in Partially Water-Filled Pipes

2012 ◽  
Author(s):  
Neal P. Bitter ◽  
Joseph E. Shepherd
Keyword(s):  
Water Depth ◽  
Water Pressure ◽  
Detonation Pressure ◽  
Shock Train ◽  
Hoop Strain ◽  
Pressure Transducers ◽  
Horizontal Pipes ◽  
Gas Layer ◽  
Transition To Detonation ◽  
Water Depths

Detonations and deflagration-to-detonation transition (DDT) are experimentally studied in horizontal pipes which are partially filled with water. The gas layer above the water is stoichiometric hydrogen-oxygen at 1 bar. For detonation cases, ignition and transition occur outside of the water-filled section. For DDT cases, ignition and transition occur over the surface of the water. Pressure and hoop strain are measured incrementally along the pipe, with pressure transducers located both above and below the water. The detonation wave produces an oblique shock train in the water, and the curvature of the pipe is seen to focus the shocks at the bottom, resulting in peak pressures that are 4–6 times higher than the peak detonation pressure. Such pressure amplification is observed for water depths of 0.25, 0.5, 0.75, 0.87, and 0.92 pipe diameters. For a water depth of 0.5 diameters, pressure is also recorded at several circumferential locations in order to measure the shock focusing phenomenon. Peak hoop strains are found to decrease with increasing water depth, and transition to detonation is seen to occur for water depths as high as 0.92 pipe diameters.

scholarly journals Heat stress in dairy calves from birth to weaning

2020 ◽  
Vol 87 (S1) ◽  
pp. 53-59
Author(s):  
Mikolt Bakony ◽  
Viktor Jurkovich
Keyword(s):  
Heat Stress ◽  
Economic Efficiency ◽  
Research Methodology ◽  
Current Knowledge ◽  
Integrated Approach ◽  
Postnatal Period ◽  
Environmental Indicators ◽  
Dairy Calves ◽  
Foetal Programming

AbstractThis Research Reflection collects current knowledge on the effects of heat stress in dairy calves. Chapters cover the concept of foetal programming, animal-based and environmental indicators of heat stress in the postnatal period, and methods of heat stress abatement. Conclusions for further research about economic efficiency, research methodology and an integrated approach of pre- and postnatal heat stress are also proposed.

scholarly journals Three-Dimensional Turbulence Numerical Simulation of Flow in a Stepped Dropshaft

Water ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 30 ◽  
Author(s):  
Yongfei Qi ◽  
Yurong Wang ◽  
Jianmin Zhang
Keyword(s):  
Flow Pattern ◽  
Water Depth ◽  
Three Dimensional ◽  
Drainage System ◽  
Urban Drainage ◽  
Pipe Network ◽  
Central Angle ◽  
Relative Water ◽  
Maximum Water ◽  
Horizontal Step

The dropshaft structure is usually applied in an urban drainage system to connect the shallow pipe network and the deep tunnel. By using the renormalization group (RNG) k~ε turbulence model with a volume of fluid method, the flow pattern and the maximum relative water depth over a stepped dropshaft with a different central angle of step were numerically investigated. The calculated results suggested that the flow in the stepped dropshaft was highly turbulent and characterized by deflection during the jet caused by the curvature of the sidewall. According to the pressure distribution on the horizontal step and the flow pattern above the step, the flow field was partitioned into the recirculating region, the wall-impinging region and the mixing region. In addition, with the increase in the central angle of step, the scope of the wall-impinging region and the mixing region increased and the scope of the recirculating region remained nearly unchanged. The maximum water depth increased with the increase in discharge. In the present work we have shown that, as the value of the central angle of step increased, the maximum water depth decreased initially and increased subsequently.

Efficient simulation of flood events using machine learning

2020 ◽  
Author(s):  
Jihane Elyahyioui ◽  
Valentijn Pauwels ◽  
Edoardo Daly ◽  
Francois Petitjean ◽  
Mahesh Prakash
Keyword(s):  
Machine Learning ◽  
Water Depth ◽  
Input Data ◽  
Learning Model ◽  
Water Levels ◽  
Training Dataset ◽  
Time Step ◽  
Machine Learning Model ◽  
Maximum Water ◽  
Spatio Temporal

<p>Flooding is one of the most common and costly natural hazards at global scale. Flood models are important in supporting flood management. This is a computationally expensive process, due to the high nonlinearity of the equations involved and the complexity of the surface topography. New modelling approaches based on deep learning algorithms have recently emerged for multiple applications.</p><p>This study aims to investigate the capacity of machine learning to achieve spatio-temporal flood modelling. The combination of spatial and temporal input data to obtain dynamic results of water levels and flows from a machine learning model on multiple domains for applications in flood risk assessments has not been achieved yet. Here, we develop increasingly complex architectures aimed at interpreting the raw input data of precipitation and terrain to generate essential spatio-temporal variables (water level and velocity fields) and derived products (flood maps) by training these based on hydrodynamic simulations.</p><p>An extensive training dataset is generated by solving the 2D shallow water equations on simplified topographies using Lisflood-FP.</p><p>As a first task, the machine learning model is trained to reproduce the maximum water depth, using as inputs the precipitation time series and the topographic grid. The models combine the spatial and temporal information through a combination of 1D and 2D convolutional layers, pooling, merging and upscaling. Multiple variations of this generic architecture are trained to determine the best one(s). Overall, the trained models return good results regarding performance indices (mean squared error, mean absolute error and classification accuracy) but fail at predicting the maximum water depths with sufficient precision for practical applications.</p><p>A major limitation of this approach is the availability of training examples. As a second task, models will be trained to bring the state of the system (spatially distributed water depth and velocity) from one time step to the next, based on the same inputs as previously, generating the full solution equivalent to that of a hydrodynamic solver. The training database becomes much larger as each pair of consecutive time steps constitutes one training example.</p><p>Assuming that a reliable model can be built and trained, such methodology could be applied to build models that are faster and less computationally demanding than hydrodynamic models. Indeed, in with the synthetic cases shown here, the simulation times of the machine learning models (< seconds) are far shorter than those of the hydrodynamic model (a few minutes at least). These data-driven models could be used for interpolation and forecasting. The potential for extrapolation beyond the range of training datasets will also be investigated (different topography and high intensity precipitation events). </p>

Changes in the Selection of Microhabitat by Juvenile Atlantic Salmon (Salmo salar) at the Summer–Autumn Transition in a Small River

1984 ◽  
Vol 41 (3) ◽  
pp. 469-475 ◽  
Author(s):  
D. M. Rimmer ◽  
U. Paim ◽  
R. L. Saunders
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Water Depth ◽  
Water Velocity ◽  
Bottom Surface ◽  
Age Classes ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Wide Range ◽  
Maximum Water

Over three summers we used direct underwater observation to examine the summer to autumn differences in seven microhabitat properties of three age-classes of juvenile Atlantic salmon (Salmo salar) in the Little Sevogle River of northeastern New Brunswick. Salmon of all three age-classes occupied a wide range of water depths during summer, but were concentrated mainly in depths of 24–36 cm. In autumn, they occurred in this range almost exclusively. The streambed stones most closely associated with the individual positions of all ages were always <20 cm in summer and mostly (84–92%) <10 cm in diameter. In autumn, all ages were associated with home stones up to 40 cm in diameter, with 65–83% of the stones exceeding 20 cm; the size of home stones selected increased with fish age in autumn. There was no apparent relationship between the water depth and home stone size distributions occupied by all age-classes and available in the stream during either summer or autumn. Summer focal water velocity (velocity at the fish's snout) was predominantly 10–30 cm∙s−1 for 0+, 10–40 cm∙s−1 for 1+, and 30–50 cm∙s−1 for 2+ salmon, but during autumn it was almost always <10 cm∙s−1 for all ages. The bottom and surface water velocities as well as the maximum water velocity within 1 m of fish stations increased with fish age during summer and autumn. At the summer–autumn transition, 0+ salmon selected higher bottom, surface, and maximum water velocities, 2+ salmon selected lower velocities, but selection by 1+ salmon remained unchanged. We view substrate size followed by water depth as the primary properties influencing stream suitability for juvenile Atlantic salmon in autumn.

scholarly journals Numerical simulation on aerosol pool scrubbing

2020 ◽  
Vol 194 ◽  
pp. 01013
Author(s):  
Cheng Peng ◽  
Dong Li ◽  
Chengyao Wang ◽  
Qinggang Lei
Keyword(s):  
Water Depth ◽  
Nuclear Power ◽  
Power Plants ◽  
Numerical Models ◽  
Particle Diameter ◽  
Free Water ◽  
Radioactive Substance ◽  
Injection Velocity ◽  
Spent Fuel ◽  
Initial Water

In the event of severe accident for nuclear power plant (NPP), radioactive aerosols may be released into spent fuel pool (SFP) through filtered-containment-venting-system (FCVS), which are entrained by mixing gas from containment, in order to prevent the overpressure of containment. The efficiency of aerosol pool scrubbing determines the radioactive threats of spent fuel compartment induced by containment venting, and the probable amount of radioactive substance during atmospheric dispersion later on. Therefore, it is necessary to study the typical flow phenomena during the process of aerosol pool scrubbing in the SFP of PWR nuclear power plants, and figure out the important regularities and mechanisms, which can provide reference for evaluations of radioactive threats of spent fuel compartment and provide technical supports for new type of designs for SFP and venting system. In this paper, Fluent is used to establish two kinds of numerical models of SFP, including horizontal injection and vertically downward injection configurations, according to the geometrical dimensions of Qinshan 2 NPP’s SFP. TiO2 is used as the substitute of radioactive substance and coupled numerical models of VOF and DPM are introduced for qualitative and quantitative studies on the effects of diameter of aerosol particle, injection velocity, initial water depth and injection direction. The decontamination factor (DF) is determined by quantifying the mass concentration of aerosol particles which escape and are traced from the SFP under different conditions, respectively. Based on the simulation results, it can be seen that with the increase of particle diameter, DF is going to decrease at first and then increase. There should be a negative correlation between injection velocity and DF. By contrast, there is a positive association between initial water depth and DF. Besides, DFs under vertically downward injection conditions are much lower than that under horizontal injection, due to the appearance of contra-vortex flow adjacent to the free water surface.

scholarly journals Experimental Studies on the Formation of Air-core inside the Drop Shaft

2018 ◽  
Vol 40 ◽  
pp. 05035
Author(s):  
Dong Sop Rhee ◽  
Hoje Seong ◽  
Inhwan Park ◽  
Hyung-jun Kim
Keyword(s):  
Water Depth ◽  
Laboratory Experiments ◽  
Experimental Studies ◽  
Underground Storage ◽  
Drop Shaft ◽  
Air Core ◽  
Multi Stage ◽  
Core Width ◽  
Maximum Water ◽  
Intake Structure

In this study, the drainage efficiency of the multi-stage intake structure, which transports flood to the underground storage, was investigated from the laboratory experiments. The multi-stage intake structure was designed based on the tangential intake and the steps on the bed were purposes to decrease the energy of approaching flow. The experimental results show that the maximum water depth was effectively decreased in the entrance of the drop shaft. The measurements results of the air core width in the drop shaft show that the flow was stably drained without the choking. Furthermore, the air core width tends to increase with the Froude number, and these results indicate that the multi-stage intake structure is applicable to convey the approaching flow with relatively high velocity.

Utilization of Jackfruit Peel as a Low-Cost adsorbent for the Removal of Methylene Blue Dye from Synthetically Polluted Water

2020 ◽  
Vol 16 ◽  
Author(s):  
Mohsina Ahmed ◽  
Abu Nasar
Keyword(s):  
Methylene Blue ◽  
Low Cost ◽  
Aqueous Media ◽  
Polluted Water ◽  
Blue Dye ◽  
Batch Adsorption ◽  
Contaminated Water ◽  
Abrupt Increase ◽  
Agriculture Waste ◽  
Pseudo Second Order

Background: Due to an abrupt increase in the contamination of freshwater systems by dye-containing wastewater, there is an urgent need to find robust and greener adsorbents for the elimination of dyes from the contaminated water. As the dyes not only change the appearance of water but are also a cause of many serious problems, which can be some time mutagenic and carcinogenic. Methods: This research paper is based on the use of adsorbent made from the peel of jackfruit (POJ). The adsorbent derived from agriculture waste was low cost and efficient for the elimination of methylene blue (MB) dye from aqueous media. Batch adsorption experiments were accompanied by varying the pH of the solution, contact time, POJ dosage, and initial MB concentration. Results: It was seen that adsorption of MB onto Jackfruit peel adsorbent follows pseudo-second-order (PSO) kinetics and Langmuir isotherm with maximum biosorption capacity (qm) of 232.55 mg/g. The thermodynamic study revealed that the adsorption was spontaneous, endothermic, and associated with the rise in entropy. Conclusion: In view of the low-cost and promising adsorption efficiency, the present investigation submits that that POJ is novel and economically feasible adsorbent for the removal of MB from aqueous solutions.

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