Formula for the maximum reference pressure at the interface of the breakwater core and filter layer

The paper describes the pore pressure measurements in a small scale breakwater model performed at Ghent University, Belgium. Two phenomena related to the pore pressure distribution within the breakwater are discussed: the amount of energy dissipation through the armour and filter layer (represented by the ‘reference pressure’) and the exponential pore pressure attenuation inside the core of the breakwater. The test results are compared with results from literature and with the empirical damping model presented by Burcharth et al. (1999) and Troch (2000). Magnitudes of the reference pressures are found to be strongly dependent on the wave steepness. The pore pressure attenuation obtained from the present experiments shows to be in accordance with the empirical damping model. A suggestion is made for a better prediction of the damping coefficient by eliminating the influence of the wave height in the empirical damping model.

Download Full-text

An Analysis of Optimum Thickness of Inverted Filter Layer Made by Manufactured Sand

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/453/1/012021 ◽

2020 ◽

Vol 453 ◽

pp. 012021

Author(s):

Jianxun Shi ◽

Lihang Hu ◽

Xingkai Zhang ◽

Jizong Liang

Keyword(s):

Optimum Thickness ◽

Manufactured Sand ◽

Filter Layer

Download Full-text

Research on Generation Method of Grasp Strategy Based on DeepLab V3+ for Three-Finger Gripper

Information ◽

10.3390/info12070278 ◽

2021 ◽

Vol 12 (7) ◽

pp. 278

Author(s):

Sanlong Jiang ◽

Shaobo Li ◽

Qiang Bai ◽

Jing Yang ◽

Yanming Miao ◽

...

Keyword(s):

Field Of View ◽

Convolution Kernel ◽

Parallel Connection ◽

Multi Scale ◽

Spatial Pyramid Pooling ◽

The Stability ◽

Parameter Values ◽

Filter Layer ◽

Complex Dataset ◽

Better Than

A reasonable grasping strategy is a prerequisite for the successful grasping of a target, and it is also a basic condition for the wide application of robots. Presently, mainstream grippers on the market are divided into two-finger grippers and three-finger grippers. According to human grasping experience, the stability of three-finger grippers is much better than that of two-finger grippers. Therefore, this paper’s focus is on the three-finger grasping strategy generation method based on the DeepLab V3+ algorithm. DeepLab V3+ uses the atrous convolution kernel and the atrous spatial pyramid pooling (ASPP) architecture based on atrous convolution. The atrous convolution kernel can adjust the field-of-view of the filter layer by changing the convolution rate. In addition, ASPP can effectively capture multi-scale information, based on the parallel connection of multiple convolution rates of atrous convolutional layers, so that the model performs better on multi-scale objects. The article innovatively uses the DeepLab V3+ algorithm to generate the grasp strategy of a target and optimizes the atrous convolution parameter values of ASPP. This study used the Cornell Grasp dataset to train and verify the model. At the same time, a smaller and more complex dataset of 60 was produced according to the actual situation. Upon testing, good experimental results were obtained.

Download Full-text

Detailed Pressure Measurements During the Transition to Rotating Stall in an Axial Compressor: Influence of the Throttling Process

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fluid Dynamics of Wind Energy; Bubble, Droplet, and Aerosol Dynamics ◽

10.1115/fedsm2018-83057 ◽

2018 ◽

Cited By ~ 1

Author(s):

Gabriel Margalida ◽

Antoine Dazin ◽

Pierric Joseph ◽

Olivier Roussette

Keyword(s):

Axial Compressor ◽

Warning Signal ◽

Rotating Stall ◽

Pressure Measurements ◽

Pressure Signal ◽

Instability Development ◽

Stable Operating ◽

Instantaneous Pressure ◽

Reference Pressure ◽

Unsteady Pressure Measurements

This paper presents experimental unsteady pressure measurements gathered on a single stage axial compressor during pre-stall and transition to stall operations. The aim of this study is to analyze the transition from a stable operating point to the fully developed rotating stall regime, and more specifically, the effect of the throttling process on the development of the instabilities. To do so, experiments have been repeated leading the compressor to stall operations with various throttling speed. On one hand, this paper analyses the effect of the throttling speed on the dynamic of the instability development from the first detection of spike type precursors to completely developed rotating stall. On the other hand, a stall warning signal based on the correlation of the instantaneous pressure signal with a reference pressure signal is built. The influence of the location of the pressure transducer used for the warning signal is first analyzed. Then an analysis of the effect of the throttling process on the time between the warning signal and the effective stall development is proposed.

Download Full-text

Comparison method of calcium analysis on filter layer water from Borobudur temple using automatic titration and atomic absorption spectrophotometer

10.1063/1.5065004 ◽

2018 ◽

Author(s):

Bayu Wiyantoko ◽

Maya Fitria ◽

Iskandar M. Siregar

Keyword(s):

Atomic Absorption ◽

Comparison Method ◽

Atomic Absorption Spectrophotometer ◽

Filter Layer ◽

Automatic Titration

Download Full-text

Effect of filter layer thickness on the filtration characteristics of dual layer granular beds

Powder Technology ◽

10.1016/j.powtec.2018.05.019 ◽

2018 ◽

Vol 335 ◽

pp. 344-353 ◽

Cited By ~ 10

Author(s):

Gui-Hui Xiao ◽

Guo-Hua Yang ◽

Qi Yang ◽

Su-Rui Tian

Keyword(s):

Layer Thickness ◽

Filter Layer

Download Full-text

Measurement and Control of a Straightening Process for Seamless Pipes

Journal of Engineering for Industry ◽

10.1115/1.2901671 ◽

1993 ◽

Vol 115 (3) ◽

pp. 347-351 ◽

Cited By ~ 4

Author(s):

T. Katoh ◽

E. Urata

Keyword(s):

Sum Of Squares ◽

Curing Process ◽

Reactive Force ◽

On Line ◽

Series Of Experiments ◽

Reference Pressure ◽

And Control ◽

Measurement And Control

This paper deals with an automatic curing process for out-of-straightness of terminal ends of seamless pipes. The developed curing process is composed of a measuring stage and a controlling stage. In the measuring stage, the out-of-straightness pattern of each pipe is measured automatically, then reference pressure points and press strokes are determined to minimize the sum of squares of deflection angles. In the controlling stage, elastic springback of the pipe is predicted by an observer using the calculated press stroke, on-line measured values of reactive force, and deflection of the pipe. Through a series of experiments, the validity of the proposed process was verified.

Download Full-text