scholarly journals A Method for Multihole Blasting Seismic Wave Prediction and Its Application in Pillar Recovery

2021 ◽  
Vol 9 ◽  
Author(s):  
Lianku Xie ◽  
Daiyu Xiong ◽  
Tianhong Yang ◽  
Li He ◽  
Qinglei Yu
Keyword(s):  
Seismic Wave ◽  
Delay Time ◽  
Far Field ◽  
Improved Method ◽  
Fundamental Vibration ◽  
Blast Vibration ◽  
Measuring Point ◽  
Blast Design ◽  
Wave Prediction ◽  
The Difference

Long-hole blasting in mines is likely to cause strong vibration of surficial infrastructure, greatly damage the rock mass surrounding goaf near explosion center, and possibly induce blast vibration disasters. In this article, an improved method for multihole blasting seismic wave prediction is proposed to estimate far-field blast vibration. In this method, the fundamental vibration waveforms are firstly measured through the field blast with a single deck at an underground pilot area. The fundamental vibration waveforms are then used to simulate the vibration waveforms for a single-deck case in the production blast by considering the difference of the equivalent distances from the production blast site and the pilot area to the surface measuring point. The vibration waveforms for the single-deck case are linearly superposed to predict the possible vibration waveforms in production blast with multiple long holes and decks according to the designed delay time between decks. Based on these predicted waveforms, the blast vibration can be estimated and the blast design can be optimized to determine a rational delay time in accordance with the vibration limit. The proposed method was applied in pillar recovery of Hongling Polymetallic Mine to optimize the long-hole blast design to manage blast vibration. The rational delay time for the 716 production blast design was recommended as 26 ms. The practice showed that the blast vibration induced by the 716 production blast has been managed, and the predicted and the measured waveforms agree well. It provides an effective method for multihole blast design to control blast vibration.

scholarly journals Estimation of Delay Times in Coupling Between Autonomic Regulatory Loops of Human Heart Rate and Blood Flow Using Phase Dynamics Analysis

2017 ◽  
Vol 9 (1) ◽  
pp. 16-22 ◽  
Author(s):  
Vladimir S Khorev ◽  
Anatoly S Karavaev ◽  
Elena E Lapsheva ◽  
Tatyana A Galushko ◽  
Mikhail D Prokhorov ◽  
...  
Keyword(s):  
Heart Rate ◽  
Delay Time ◽  
Healthy Subjects ◽  
Low Frequency ◽  
Phase Dynamics ◽  
Oscillatory Systems ◽  
Low Frequency Oscillations ◽  
Delay Times ◽  
The Difference ◽  
Regulatory Loop

Objective: We assessed the delay times in the interaction between the autonomic regulatory loop of Heart Rate Variability (HRV) and autonomic regulatory loop of photoplethysmographic waveform variability (PPGV), showing low-frequency oscillations. Material and Methods: In eight healthy subjects aged 25–30 years (3 male, 5 female), we studied at rest (in a supine position) the simultaneously recorded two-hour signals of RR intervals (RRIs) chain and finger photoplethysmogram (PPG). To extract the low-frequency components of RRIs and PPG signal, associated with the low-frequency oscillations in HRV and PPGV with a frequency of about 0.1 Hz, we filtered RRIs and PPG with a bandpass 0.05-0.15 Hz filter. We used a method for the detection of coupling between oscillatory systems, based on the construction of predictive models of instantaneous phase dynamics, for the estimation of delay times in the interaction between the studied regulatory loops. Results: Averaged value of delay time in coupling from the regulatory loop of HRV to the loop of PPGV was 0.9±0.4 seconds (mean ± standard error of the means) and averaged value of delay time in coupling from PPGV to HRV was 4.1±1.1 seconds. Conclusion: Analysis of two-hour experimental time series of healthy subjects revealed the presence of delay times in the interaction between regulatory loops of HRV and PPGV. Estimated delay time in coupling regulatory loops from HRV to PPGV was about one second or even less, while the delay time in coupling from PPGV to HRV was about several seconds. The difference in delay times is explained by the fact that PPGV to HRV response is mediated through the autonomic nervous system (baroreflex), while the HRV to PPGV response is mediated mechanically via cardiac output.

scholarly journals The difference of delay time in monitoring system of facial acupressure learning media using bluetooth, wireless and ethernet

2018 ◽  
Author(s):  
Eny Widhia Agustin ◽  
Arimaz Hangga ◽  
Muhammad Iqbal Fahrian ◽  
Anis Fikri Azhari
Keyword(s):  
Monitoring System ◽  
Delay Time ◽  
The Difference

Production Blast-Induced Vibrations in Longhole Open Stoping

2012 ◽  
pp. 160-170
Author(s):  
John Henning ◽  
Hani Mitri
Keyword(s):  
Mining Operation ◽  
Metal Mining ◽  
Blast Vibration ◽  
Zone Width ◽  
Blast Design ◽  
Design Practices ◽  
Powder Factor ◽  
Vibration Attenuation ◽  
Stope Design

This paper examines stope design approaches employed at a metal mining operation in Canada for extraction of transverse primary, transverse secondary, and longitudinal stopes. Variations in stope and slot design, blast design, and blast vibration attenuation are presented in detail. It is shown that the type of blasthole stoping technique employed varies according to stope sequence and ore zone width. Within this range of stopes, blasting design practices have been standardized in terms of drillhole diameter, powder factor, and the type and pattern of the explosives used.

Damage-Involved Response of Two Colliding Buildings under Non-Uniform Earthquake Loading

2013 ◽  
Vol 577-578 ◽  
pp. 197-200
Author(s):  
Robert Jankowski
Keyword(s):  
Ground Motion ◽  
Seismic Wave ◽  
Damage Model ◽  
Fem Analysis ◽  
Stochastic Modelling ◽  
Earthquake Loading ◽  
Non Linear ◽  
San Fernando ◽  
The Difference ◽  
Ground Motion Records

Pounding between insufficiently separated buildings, which may result in considerable damage or may even lead to the total collapse of colliding structures, has been repeatedly observed during earthquakes. Earthquake-induced collisions of buildings has been intensively studied applying various structural models. It was assumed in the analyses, however, that the seismic excitation is identical for all structural supports; whereas, in the reality, the ground motion differs from place to place due to spatial seismic effects connected with propagation of the seismic wave. The aim of the present paper is to conduct a detailed non-linear damage-involved analysis of pounding between two structures under non-uniform earthquake loading. A case of pounding between the Olive View Hospital main building and one of its stairway towers, observed during the San Fernando earthquake of 1971, has been considered in the study. In the numerical FEM analysis, non-linear material properties have been simulated using stiffness degradation (due to damage under cyclic loading) model of concrete and elastoplastic damage model of reinforcing steel. A method of conditional stochastic modelling has been used to generate the input ground motion records. The results of the study indicate that the incorporation of the non-uniform ground motion excitation may lead to substantial change of pounding-involved response of the structures. The difference between the uniform and non-uniform responses has been found to be relatively large considering the fact that the variation in the simulated input ground motion records was rather small. This shows the importance of incorporation in the damage-involved numerical analysis the effects connected with propagation of the seismic wave.

Delay time and phase of the initial state

1970 ◽  
Vol 48 (6) ◽  
pp. 639-652 ◽  
Author(s):  
Tran Trong Gien
Keyword(s):  
Phase Change ◽  
Delay Time ◽  
Three Dimensional ◽  
Time Operator ◽  
Initial State ◽  
Average Delay ◽  
Average Delay Time ◽  
S Matrix ◽  
The Difference

The study presented in this paper is intended to show how to calculate the average delay time of a scattering within the framework of the delay time operator Q in order to prove that the average delay time is independent from the phase of the initial state. This conclusion differs from Ohmura's assertion in a recent paper that in the three-dimensional scattering, the average delay time depends on the phase change of the initial state. Our result saves the hope that the delay time of a collision can be known in terms of the S matrix alone. The reason for the difference between our result and Ohmura's is also discussed. We also investigate the commutation of the Q and S matrices and search for the interesting consequences of this commutation.

Dissolution of CO2 From CO2 Drops in Simulating Experiments of CO2 Ocean Storage

2004 ◽  
Author(s):  
Yasuharu Nakajima ◽  
Hideyuki Shirota ◽  
Ryuji Kojima ◽  
Kenji Yamane ◽  
Izuo Aya ◽  
...  
Keyword(s):  
Deep Sea ◽  
Co2 Concentration ◽  
The Other ◽  
Temperature Dependency ◽  
Ph Change ◽  
Measuring Point ◽  
Hydrate Film ◽  
The Difference ◽  
Carbon Dioxide Co2 ◽  
Two Temperature

The dissolution of Carbon Dioxide (CO2) from CO2 drops covered with CO2 hydrate films under the conditions simulating the deep-sea environment was investigated with a large high-pressure tank. The lowering of pH due to CO2 dissolution was measured for two temperature regions. In the same temperature region, pH lowering at higher position above the bottom of the tank was much smaller than that at lower position. It implies that while the dissolved CO2 is diffused through water in the tank, the difference in CO2 concentration occurs between both measuring points. On the other hand, pH lowering in the lower temperatures was smaller than that in the higher temperatures at the same measuring point. The difference in pH change between both temperature regions agreed with the temperature dependency in the solubility of CO2 hydrate and the dissolution rate of a CO2 droplet with a CO2 hydrate film.

Comparative Study on Aerodynamic Noise of Dimensionally Similar Locomotive Models of High Speed Trains

2012 ◽  
Vol 226-228 ◽  
pp. 417-422
Author(s):  
Yi Gang Wang ◽  
Yang Yang ◽  
Jia Shun Yang ◽  
Zhi Gang Yang
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Spectral Characteristics ◽  
Wind Tunnel Test ◽  
Scale Model ◽  
Source Distribution ◽  
Aerodynamic Noise ◽  
Far Field ◽  
The Difference ◽  
Field Noise

This study is focused on the locomotive of high speed train. First, wind tunnel test is used to verify the credibility of numerical results. Then, in order to compare the difference of aerodynamic noise generated by different size locomotive, dimensionally similar models of 1/8th, 1/12th and 1/15th scale are studied by using numerical simulation, including stationary aerodynamic characteristics, fluctuation characteristics of unsteady flow, noise source distribution on surface and far-field noise spectral characteristics. Based on the result of pressure fluctuation, it is noted that the difference between 1/15th and 1/8th scale model is larger in individual parts, including the separation zone in the roof and the edge of window. In addition, according to the far-field noise calculation, the result of 1/12th scale model is better than 1/15th scale model. From the results mentioned above, 1/15th or much smaller scale model should not be used in wind tunnel test as possible.

An improved method for extracting the difference between drain and source resistances in MOSFETs

1996 ◽  
Vol 39 (3) ◽  
pp. 419-421 ◽  
Author(s):  
A Ortiz-Conde ◽  
F.J Garcia Sanchez ◽  
J.J Liou
Keyword(s):  
Improved Method ◽  
The Difference

scholarly journals PENGUKURAN LAJU ALIRAN UDARA DALAM PIPA SECARA SIMULTAN DENGAN TRANSDUSER GANDA ULTRASONIK

2021 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Lalu Febrian Wiranata
Keyword(s):  
Delay Time ◽  
Time Of Flight ◽  
Hot Wire ◽  
The Difference ◽  
The One

This paper aims to modification the transducer ultrasonic for measuring the distance to develop measure time of flight in the pipe with simultaneous method. To implement the application, we try to develop the microcontroller with one command transmitter and one command receiver in the same time, different from the conventional way, the transmitter and receiver work with consecutively. We try to reduce the delay time in two different transducers. In industrial, the symmetries profile must be ensured the profile always laminar. In this research, we try to use one path configuration. The result with the reference hot wire, we got the 27.76 percentage the difference of result. This is because the hot wire can measure the one path of flow in the one way of dot point.

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