Recognition and Knowledge of the Water-Level Principle

Perception ◽  
1978 ◽  
Vol 7 (2) ◽  
pp. 151-160 ◽  
Author(s):  
Ian P Howard
Keyword(s):  
Water Level ◽  
Present Experiment ◽  
Three Dimensional ◽  
Fluid Level ◽  
Fluid Surface ◽  
Correct Orientation ◽  
Perceptual Schema

Piaget and Inhelder showed that children do not realize that the surface of a fluid remains horizontal in a tilted vessel. Several studies have since shown that many adults do not have an adequate concept of the water-level principle. However, in all these studies, drawings of vessels, or other abstract displays, were used. The present experiment is an investigation of whether adults who do not know the water-level principle are able to recognize the correct orientation of a fluid surface in realistic three-dimensional scenes and in cinematographic sequences. It was found that all subjects who could state the principle clearly, could precisely and accurately recognize the correct fluid level. More than half the subjects did not know the principle and all these subjects showed evidence in their judgments of only the crudest perceptual schema.

scholarly journals A numerical geotechnical model for computing soil slides at banks of water reservoirs

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Nils Reidar B. Olsen ◽  
Stefan Haun
Keyword(s):  
Numerical Model ◽  
Water Level ◽  
Stokes Equations ◽  
Limit Equilibrium ◽  
Three Dimensional ◽  
Field Measurements ◽  
Navier Stokes ◽  
Adaptive Grids ◽  
Groundwater Levels ◽  
Before And After

AbstractSoil slides can occur when the water level in a lake or a reservoir is lowered. This may take place in situations when a reservoir is flushed to remove sediments. The current study describes a three-dimensional numerical model used for the simulation of reservoir flushing that includes the slide movements. The geotechnical failure algorithms start with modelling the groundwater levels at the banks of the reservoir. A limit equilibrium approach is further used to find the location of the slides. The actual movement of the sediments is computed by assuming the soil to be a viscous liquid and by solving the Navier–Stokes equations. The resulting bed elevation changes from the slides are computed in adaptive grids that change as a function of water level, bed erosion and slide movements. The numerical model is tested on the Bodendorf reservoir in Austria, where field measurements are available of the bank elevations before and after a flushing operation. The results from the numerical simulations are compared with these observations. A parameter test shows that the results are very sensitive to the cohesion and less sensitive to the E and G modules of the soil.

scholarly journals Non-Contact Water Level Response Measurement of a Tubular Level Gauge Using Image Signals

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2217 ◽  
Author(s):  
Sung-Wan Kim ◽  
Dong-Uk Park ◽  
Bub-Gyu Jeon ◽  
Sung-Jin Chang
Keyword(s):  
Water Level ◽  
Storage Tank ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Level Gauge ◽  
Fluid Level ◽  
Response Measurement ◽  
Liquid Storage ◽  
Fluid Sloshing ◽  
Liquid Storage Tank

The occurrence of excessive fluid sloshing during an earthquake can damage structures used to store fluids and can induce secondary disasters, such as environmental destruction and human casualties, due to discharge of the stored fluids. Thus, to prevent such disasters, it is important to accurately predict the sloshing behavior of liquid storage tanks. Tubular level gauges, which visually show the fluid level of a liquid storage tank, are easy to install and economical compared to other water level gauges. They directly show the fluid level and can be applied for various fluids because they can be constructed with various materials according to the fluid characteristics and the intended use. Therefore, in this study, the shaking table test was conducted to verify the validity of the method for measuring the water level response of the tubular level gauge installed on a liquid storage tank using image signals. In addition, image enhancement methods were applied to distinguish between the float installed in the tubular level gauge and the gray level of the background.

Preserved Priming of Novel Objects across Size Transformation in Amnesic Patients

1993 ◽  
Vol 4 (5) ◽  
pp. 331-335 ◽  
Author(s):  
Daniel L. Schacter ◽  
Lynn A. Cooper ◽  
Jonathan Treadwell
Keyword(s):  
Explicit Memory ◽  
Present Experiment ◽  
Three Dimensional ◽  
Decision Task ◽  
Structural Description ◽  
Test Size ◽  
Visual Objects ◽  
Novel Objects ◽  
Invariant Representations

Previous research has indicated that amnesic patients can show normal priming of novel objects on a decision task in which subjects decide whether unfamiliar structures could or could not exist in the three-dimensional world. The present experiment reveals that amnesic patients exhibit normal priming on this task across a study-to-test size transformation despite impaired explicit memory. These results suggest that priming of novel objects in amnesia depends on a spared structural description system that computes size-invariant representations of visual objects.

scholarly journals Application and Verification of a three-dimensional Hydrodynamic Model to Hamilton Harbour, Canada

2013 ◽  
Vol 2 (1) ◽  
pp. 77-89
Keyword(s):  
Water Level ◽  
Hydrodynamic Model ◽  
Three Dimensional ◽  
Model Verification ◽  
Water Current ◽  
Trajectory Model ◽  
Hamilton Harbour ◽  
Water Level Changes ◽  
Model Predictions ◽  
Good Agreement

A multi-layered three-dimensional hydrodynamic model has been developed to provide flow fields and water level changes in Hamilton Harbour. The field data collected in Hamilton Harbour during 1990 & 1991 field seasons was used for model verification. The simulated currents were compared with current meter data. Results from the trajectory model are in good agreement with the drogue experimental data. A quantitative criterion to evaluate the trajectory comparison was established with the help of the trajectory model using the random-walk approach. By using the water level changes in the Burlington Ship Canal, the model predictions were validated with the measurements at three water level stations in the Harbour. These comparisons demonstrate that the models can simulate the major features of the water current and level changes in Hamilton Harbour.

The ABCs of Covariance

2019 ◽  
Vol 112 (5) ◽  
pp. 352-358
Author(s):  
Rick Stuart ◽  
Matt Chedister
Keyword(s):  
Water Level ◽  
Three Dimensional ◽  
Elapsed Time ◽  
The Relationship

While filling three-dimensional letters, students analyzed the relationship between the height of water level and elapsed time.

Reflex compensation of voluntary inspiration when immersion changes diaphragm length

1985 ◽  
Vol 59 (2) ◽  
pp. 611-618 ◽  
Author(s):  
R. B. Banzett ◽  
R. W. Lansing ◽  
M. B. Reid
Keyword(s):  
Tidal Volume ◽  
Water Level ◽  
Lung Volume ◽  
Present Experiment ◽  
Muscle Activation ◽  
Repeated Measurements ◽  
Inspiratory Muscle ◽  
Reflex Compensation ◽  
Spontaneously Breathing ◽  
Surface Electromyograms

When immersion alters inspiratory muscle operating lengths, spontaneously breathing humans maintain a constant tidal volume by reflex adjustment of inspiratory muscle activation (Reid et al. J. Appl. Physiol. 58: 1136–1142, 1985). We term this the operational length compensation reflex. The present experiment demonstrates that similar adjustments occur during voluntary respiratory maneuvers. Each of seven naive subjects sat in a tank with water at hip level. We trained them to reproduce an inspired volume (+/- 10%) at constant inspiratory duration. They received verbal feedback during training but not during the experiment. We measured surface electromyograms (EMGs) of diaphragm and intercostal muscles and tidal volume. After the subjects were trained, we made repeated measurements of 10 trained breaths with water at the hip and then again after raising water level to the xiphoid (which decreases lung volume and increases operating length of the diaphragm). In 30 of 42 trials there was a substantial fall in peak diaphragm EMG. In 10 trials this was sufficient to prevent any change in tidal volume. Inspiratory flow was more closely regulated than tidal volume. Subjects were not aware of making adjustments in drive.

scholarly journals Design and Implementation of a Wireless Fluid Level Display System Using Ultrasonic Sensing Technique

2020 ◽  
pp. 30-40
Author(s):  
Gesa F. Newton ◽  
Terwase I. Aondona ◽  
C. A. Chile
Keyword(s):  
Response Time ◽  
Water Level ◽  
Water Levels ◽  
Average Response ◽  
Display System ◽  
Average Response Time ◽  
Fluid Level ◽  
Crystal Oscillator ◽  
Design And Implementation ◽  
Ultrasonic Sensing

The wireless fluid level indicator comprises a sensing and transmitting circuit for detecting and transmitting the levels of fluids from a container to the receiving circuit which receives and displays the amount of the measured volume. This has been achieved using an ultrasonic sensor (HC-SR04), a firmware (PIC16F648A/PIC16F876A microcontroller programmed in C/assembly languages), an encoder (HT12E) and a radio frequency (RF) transmitter transmitting at a bandwidth of 433MHz to an RF receiver interfaced with a decoder (HT12D), liquid crystal display (LCD) and a Buzzer. The device when tested measured water levels and transmitted same over a distance of up to 98.5 meters in open areas and up to 50 meters in highly obstructed areas. The average response time was also estimated to be 0.1 second. As a contact-less depth detection system, the device finds useful applications in measurement of fluid levels in homes and industries where concentrates, table water, transmission oils are produced, without affecting the chemical or physical properties of such substances-an advantage over the contact methods used in fluid level detection. Aims: To design and implement a wireless microcontroller based fluid level display system using ultrasonic sensing method. Study Design: By encoding the Transmitter module to sense and detect the amount of water level, while the decoder module decodes the received data and display the result. Place and Duration of Study: Department of Physics, University of Agriculture Makurdi, Benue State, Nigeria, between November 2018 and April 2019. Methodology: An RF transceiver, encoder/decoder (HT12E/HT12D), a 2x16 Liquid display module, 4MHz crystal oscillator, a buzzer and other peripherals were interfaced to two 8-bit controllers; PIC16F648A and PIC16F876A. The controllers were programmed in C/Assembly languages to enable effective communication of the system. The system was then calibrated to read and transmit water level values from a 30-centimeter deep tank over a distance of 1.0 - 98.5 meters. Results: The system was tested to have maximum sensitivity over a distance of 98.5 meters in non-obstructed areas and 50 meters in obstructed areas. The average response time was also estimated to be 0.5 seconds. Conclusion: The design and implementation of a wireless fluid level display system using ultrasonic sensing technique has been successfully done. The system workability is suitable for deployment and usage in domestic and industrial purposes.

scholarly journals 3D numerical modeling of flow and sediment transport in rivers and open channels

2019 ◽  
Vol 3 (1) ◽  
pp. 23-36
Author(s):  
Le Song Giang ◽  
Tran Thi My Hong
Keyword(s):  
Boundary Condition ◽  
Sediment Transport ◽  
Numerical Model ◽  
Differential Equations ◽  
Water Level ◽  
Suspended Sediment ◽  
Three Dimensional ◽  
River Bed ◽  
Suspended Sediment Concentrations ◽  
Flow And Sediment Transport

Numerical model is a useful tool in studying the flow and sediment transport, change in river bed and is built on solving governing differential equations. Numerical model has many different levels and three-dimensional model is the highest level, allowing detailed simulation of flow and sediment transport process in 3D space. The paper presents a method calculating three - dimensional flow and sediment transport in the open channel. Water level and flow velocity are solved from three-dimensional equations with hydrostatic hypothesis. Concentration of suspended sediment, bottom sediment and bottom evolution is solved from transport equations. The governing differential equations in the "sigma" transform coordinate system are solved by finite volume method on unstructured grid of quadrilateral elements. Boundary condition of water level or flow will be imposed on open boundary. For suspended sediment concentrations in the injected phase, suspended sediment concentrations are applied and the outflow phase applies free drainage conditions. This method of calculation was tested with the problem of curved channel sediment transport which was studied experimentally by Odgaard and Bergs. Calculation results are quite consistent with the measured data. In order to test the practical applicability, this method is also tested with the problem of sediment transport in Cu lao Pho islet on Dong Nai river. To solve the matter of hydraulic boundary condition of this problem, the model of Cu lao Pho islet is integrated into the Sai Gon - Dong Nai river system model. Results of the calculation of the river bed evolution of the Cu lao Pho islet on the Dong Nai river also show that this calculation method gives results consistent with the rule and can be used in practical research.  

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