A lumped parameter model of mechanically mediated acute and long-term adaptations of contractility and geometry in lymphatics for characterization of lymphedema

A lumped parameter model of the Czochralski crystal growth process is proposed that captures the dominant nonlinear dynamics, internal coupling, and disturbance structure. Conventional and advanced actuators are modeled. The dynamic characteristics of the interface shape and input/outputs that limit the achievable controller performance are identified.

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Can high rates of passive volcanic gas emissions induce reservoir depressurization at Ambrym volcano (Vanuatu)?

10.5194/egusphere-egu21-7998 ◽

2021 ◽

Author(s):

Tara Shreve ◽

Raphaël Grandin ◽

Marie Boichu

Keyword(s):

Ground Deformation ◽

Lumped Parameter Model ◽

Magma Ascent ◽

Large Reservoir ◽

Gas Emissions ◽

Volcanic System ◽

Lumped Parameter ◽

Gas Geochemistry ◽

The Impact

Satellite-based UV spectrometers can constrain sulphur dioxide (SO2) fluxes at passively degassing volcanoes over decadal time scales. From 2005 to 2015, more than 15 volcanoes had mean passive SO2 fluxes greater than 1 kiloton per day. Although the processes responsible for such high emission rates are not clearly established, this study aims to investigate the impact of strong degassing on the pressurization state of volcanic systems and the resulting ground deformation. One possible result of high degassing rates is the depressurization of the region where the melt releasing gas is stored, which may result in subsidence at the Earth&#8217;s surface. Passive degassing may depressurize pathways between deep and shallow magma storage regions, resulting in magma ascent and possibly eruption.A lumped-parameter model developed by Girona et al., 2014 couples the mass loss by passive degassing with reservoir depressurization in an open volcanic system. However, this model has yet to be tested using real measurements of gas emissions and ground deformation. In our study, we focus on Ambrym volcano, the past decade&#8217;s top passive emitter of volcanic SO2, which exhibits intriguing long-term subsidence patterns and no obvious pressurization preceding eruptive periods. We compare subsidence rates measured by InSAR to the system&#8217;s average daily SO2 flux, focusing on a subsidence episode spanning 2015 to 2017 that is not clearly linked to magma removal from the system. Using realistic input parameters for Ambrym&#8217;s system constrained by petrology and gas geochemistry, a range of reservoir volumes and conduit radii are explored. Large reservoir volumes (greater than 30 km3) and large conduit radii (greater than 300 m) are consistent with depressurization rates obtained from geodetic modelling of InSAR measurements using the Boundary Element method. By comparing these values of reservoir volume and conduit radius with those estimated from geodesy, gas geochemistry, and seismology, we test the applicability and discuss uncertainties of the aforementioned lumped-parameter physical model to interpret the long-term subsidence at Ambrym volcano as a result of sustained passive degassing.

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Characterization of a Resonant MEMS Heat Engine

Volume 3: Combustion Science and Engineering ◽

10.1115/imece2008-67926 ◽

2008 ◽

Author(s):

H. Bardaweel ◽

R. Richards ◽

C. Richards ◽

M. Anderson

Keyword(s):

Transfer Function ◽

Heat Engine ◽

Lumped Parameter Model ◽

Function Approach ◽

Heat Rejection ◽

Dynamic Operation ◽

Linear Transfer Function ◽

At Resonance ◽

Lumped Parameter

The dynamic operation of a MEMS heat engine has been studied using a linear transfer function approach. The engine was operated at resonance and shown to produce a cycle with a PV diagram. A lumped parameter model was developed and validated. The model was used to explore the heat rejection process and its effect on the pressure volume diagram.

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A Lumped-Parameter Model of Multiscale Dynamics in Steam Supply Systems

Journal of Computational and Nonlinear Dynamics ◽

10.1115/1.4034491 ◽

2016 ◽

Vol 11 (6) ◽

Cited By ~ 2

Author(s):

Hikaru Hoshino ◽

Yoshihiko Susuki ◽

Takashi Hikihara

Keyword(s):

Power Systems ◽

Lumped Parameter Model ◽

Distributed Parameter ◽

Short Term ◽

Distributed Parameter Model ◽

Multiscale Dynamics ◽

Lumped Parameter ◽

Normally Hyperbolic Invariant Manifold ◽

Supply Systems

This paper focuses on multiscale dynamics occurring in steam supply systems. The dynamics of interest are originally described by a distributed-parameter model for fast steam flows over a pipe network coupled with a lumped-parameter model for slow internal dynamics of boilers. We derive a lumped-parameter model for the dynamics through physically relevant approximations. The derived model is then analyzed theoretically and numerically in terms of existence of normally hyperbolic invariant manifold in the phase space of the model. The existence of the manifold is a dynamical evidence that the derived model preserves the slow–fast dynamics, and suggests a separation principle of short-term and long-term operations of steam supply systems, which is analog to electric power systems. We also quantitatively verify the correctness of the derived model by comparison with brute-force simulation of the original model.

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Design and Performance of Hand-Struck Tools Using High Performance Polymers

Design Engineering, Volumes 1 and 2 ◽

10.1115/imece2003-41455 ◽

2003 ◽

Author(s):

J. L. Glancey ◽

P. Popper ◽

T. Nasr ◽

P. Truitt ◽

M. Orgovan ◽

...

Keyword(s):

High Performance ◽

Field Tests ◽

Element Model ◽

Lumped Parameter Model ◽

Force Transmission ◽

Transmission Characteristics ◽

High Performance Polymers ◽

Lumped Parameter ◽

And Performance

One of the oldest tools in the world, the hand-struck chisel, has been improved with the addition of a polymer cap. The cap enhances the safety and ergonomic features without compromising chisel cutting performance. During the development of this new design, a lumped-parameter model was used to quantify force transmission characteristics, and select a suitable polymer-reinforced nylon (Minlon™). In addition, a finite element model together with laboratory and field tests were used to demonstrate that the addition of the polymer cap significantly reduces chisel vibration and noise. Additional long term tests confirmed the cutting effectiveness and durability of the capped chisel.

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Experimental Characterization of the Electrostatic Levitation Force in MEMS Transducers

Journal of Vibration and Acoustics ◽

10.1115/1.4046625 ◽

2020 ◽

Vol 142 (4) ◽

Cited By ~ 3

Author(s):

Meysam Daeichin ◽

Ronald N. Miles ◽

Shahrzad Towfighian

Keyword(s):

Degrees Of Freedom ◽

Levitation Force ◽

Electrostatic Force ◽

Experimental Results ◽

Lumped Parameter Model ◽

Electrostatic Levitation ◽

Experimental Procedure ◽

Lumped Parameter ◽

Micro Electromechanical System

Abstract In this study, a two-step experimental procedure is described to determine the electrostatic levitation force in micro-electromechanical system transducers. In these two steps, the microstructure is excited quasi-statically and dynamically and its response is used to derive the electrostatic force. The experimental results are obtained for a 1 mm by 1 mm plate that employs 112 levitation units. The experimentally obtained force is used in a lumped parameter model to find the microstructure response when it is subjected to different dynamical loads. The natural frequency and the damping ratios in the model are identified from the experimental results. The results show that this procedure can be used as a method to extract the electrostatic force as a function of the microstructure’s degrees-of-freedom. The procedure can be easily used for any microstructure with a wide variety of electrode configurations to predict the response of the system to any input excitation.

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