Source parameters and three-dimensional attenuation structure from the inversion of microearthquake pulse width data: Method and synthetic tests

2001 ◽  
Vol 106 (B8) ◽  
pp. 16287-16306 ◽  
Author(s):  
Aldo Zollo ◽  
Salvatore de Lorenzo
Keyword(s):  
Pulse Width ◽  
Source Parameters ◽  
Three Dimensional ◽  
Attenuation Structure

scholarly journals Three-Dimensional Arterial Pulse Signal Acquisition in Time Domain Using Flexible Pressure-Sensor Dense Arrays

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 569
Author(s):  
Jianzhong Chen ◽  
Ke Sun ◽  
Rong Zheng ◽  
Yi Sun ◽  
Heng Yang ◽  
...  
Keyword(s):  
Radial Artery ◽  
Pressure Sensor ◽  
Pulse Width ◽  
Printed Circuit Boards ◽  
Color Doppler ◽  
Three Dimensional ◽  
Pressure Sensors ◽  
Sensor Arrays ◽  
Signal Acquisition ◽  
Dynamic Pulse

In this study, we developed a radial artery pulse acquisition system based on finger-worn dense pressure sensor arrays to enable three-dimensional pulse signals acquisition. The finger-worn dense pressure-sensor arrays were fabricated by packaging 18 ultra-small MEMS pressure sensors (0.4 mm × 0.4 mm × 0.2 mm each) with a pitch of 0.65 mm on flexible printed circuit boards. Pulse signals are measured and recorded simultaneously when traditional Chinese medicine practitioners wear the arrays on the fingers while palpating the radial pulse. Given that the pitches are much smaller than the diameter of the human radial artery, three-dimensional pulse envelope images can be measured with the system, as can the width and the dynamic width of the pulse signals. Furthermore, the array has an effective span of 11.6 mm—3–5 times the diameter of the radial artery—which enables easy and accurate positioning of the sensor array on the radial artery. This study also outlines proposed methods for measuring the pulse width and dynamic pulse width. The dynamic pulse widths of three volunteers were measured, and the dynamic pulse width measurements were consistent with those obtained by color Doppler ultrasound. The pulse wave velocity can also be measured with the system by measuring the pulse transit time between the pulse signals at the brachial and radial arteries using the finger-worn sensor arrays.

scholarly journals 3D-printed Planktonic Observational Setup and Analysis Pipeline TrackmateTaxis

2020 ◽  
Author(s):  
Clemens C. Döring ◽  
Harald Hausen
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Photon Emission ◽  
Three Dimensional ◽  
Behavioral Observation ◽  
Swimming Behavior ◽  
Robust Tracking ◽  
Light Path ◽  
Analysis Pipeline ◽  
3D Printed

AbstractPlanktonic organisms are a cornerstone of marine ecosystems. They vary significantly in size and have a repertoire of behaviors to aid them to survive and navigate their three-dimensional environment. One of the most important cues is light. A variety of setups were used to study the swimming behavior of specific organisms, but broader and comparative investigations need more versatile solutions. With the help of 3D printing, we designed and constructed a modular and flexible behavioral observation setup that enables recordings of animals down to 50μm or up to a few centimeters. A video analysis pipeline using ImageJ and python allows a quick, automated, and robust tracking solution, capable of processing many videos automatically. A modular light path allows the addition of filters or use of pulse width modulation to equalize photon emission of LEDs or additional LEDs to mix different wavelengths. Optionally, a spectrometer can be installed to enable live monitoring of a stimulus. We tested the setup with two phototactic marine planktonic larvae. First, we investigated the spectral sensitivity of the 7-day old larvae of the polychaete Malacoceros fuliginosus and second, the behavior of the 200μm spherical bryozoan coronated larvae of Tricellaria inopinata to ultraviolet light coming from the bottom of the vessel. The setup and pipeline were able to record and analyze hundreds of animals simultaneously. We present an inexpensive, modular, and flexible setup to study planktonic behavior of a variety of sizes.

COUPLING OF EXPLOSIVE ENERGY IN THREE‐DIMENSIONAL MODELS

Geophysics ◽  
1970 ◽  
Vol 35 (2) ◽  
pp. 220-233
Author(s):  
Dhari S. Bahjat ◽  
Carl Kisslinger
Keyword(s):  
Pulse Width ◽  
Surrounding Medium ◽  
Three Dimensional ◽  
P Wave ◽  
Elastic Response ◽  
Laboratory Model ◽  
Cavity Radius ◽  
General Validity ◽  
Short Period ◽  
Tightly Coupled

The coupling of explosive generated P waves to the surrounding medium was investigated in a three‐dimensional laboratory model. For tightly coupled charges the amplitude was found to increase as [Formula: see text], and the pulse width as [Formula: see text], where W is the charge mass. Only a few hundredths of one percent of the energy in the explosion was transmitted in the initial P wave. When charges were fired in air‐filled cavities, the amplitude of the energy in the P wave increased to a maximum and then decreased with increasing cavity radius. The amplitudes from cavity shots were never less than the amplitudes for the tightly coupled shots. As the cavity radius increased, the pulse width of the P wave decreased to a minimum, an indication of a decrease in the size of the equivalent cavity, and then increased with further increase in cavity size. The period minimum is interpreted as corresponding to the transition from nonelastic to elastic response of the cavity wall. The cavity pressure at this transition is about one‐half the nominal tensile strength of the material. Scaling to the Sterling nuclear event is examined, and the conclusion is that the disagreement between field tests of decoupling and our experiments is due to the dominance of short period energy in our experiments. The results cast doubt on the general validity of partial decoupling.

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