Simulation of Photoresist Thermal Flow Process with Viscous Flow Model

The efficacy of radiofrequency ablation (RFA) treatments depends on the ability to ablate tumors completely while minimizing the damage to healthy tissue. Tissue cooling due to blood flow is an important factor affecting the size and shape of the ablation lesion. In this paper a new methodology for finite element modeling of the coupled electrical-thermal-flow process during RFA is presented. Our formulation treats heat losses due to blood flow explicitly rather than approximating the collective effects of blood vessles as a heat sink. Numerical models were compared to in vitro models using egg whites to simulate human tissue and a straight cylinder filled with a saline solution to simulate blood. Asymmetric burns were obtained close to the simulated blood vessels. Numerical results closely match the in vitro models.

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Photoresist flow simulation using the viscous flow model

International Conference on Simulation of Semiconductor Processes and Devices, 2003. SISPAD 2003. ◽

10.1109/sispad.2003.1233633 ◽

2003 ◽

Cited By ~ 1

Author(s):

Won-young Chung ◽

Tai-kyung Kim ◽

Young-tae Kim ◽

Byung-joon Hwang ◽

Young-kwan Park ◽

...

Keyword(s):

Viscous Flow ◽

Flow Model ◽

Flow Simulation

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A Comparison Between Experimental and Predicted Flow Profiles Beneath a Semi-Confined Axisymmetric Impinging Jet

Volume 5: Turbo Expo 2003, Parts A and B ◽

10.1115/gt2003-38493 ◽

2003 ◽

Author(s):

C. Y. Cheong ◽

P. T. Ireland ◽

S. Ashforth-Frost

Keyword(s):

Viscous Flow ◽

Flow Model ◽

Three Dimensional ◽

Impinging Jet ◽

Theoretical Models ◽

Velocity Profiles ◽

Axisymmetric Case ◽

Air Jet ◽

Wall Flow ◽

Near Wall

Theoretical predictions have been compared with experiment for a single semi-confined impinging jet. The turbulent air jet discharged at Re = 20 000 and impinged at nozzle-to-plate spacings (z/d) of 2 and 6.5. Experimental velocity profiles were obtained using hot-wire anemometry. Theoretical velocity profiles were derived using stagnation three-dimensional flow model and viscous flow model for an axisymmetric case. For z/d = 2, velocity profiles in the inviscid region of the near wall flow can be predicted accurately using the stagnation flow model. As the edge of the jet is approached, the flow becomes complex and, as expected, cannot be predicted using the model. Prediction of boundary layer profiles using the viscous flow solution for an axisymmetric case is also reasonable. For z/d = 6.5, the developing impinging jet is essentially turbulent on impact and consequently predictions of near wall flow field, using both the theoretical models, are inappropriate.

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Molecular Association of Tetramethylurea and Chlorobenzene Molecules in Microwave Frequency Range

Zeitschrift für Naturforschung A ◽

10.1515/zna-2010-1012 ◽

2010 ◽

Vol 65 (10) ◽

pp. 854-858

Author(s):

Vimal Sharma ◽

Nagesh Thakur

Keyword(s):

Relaxation Time ◽

Dielectric Relaxation ◽

Viscous Flow ◽

Relaxation Process ◽

Binary Mixtures ◽

Variation Method ◽

Dielectric Relaxation Time ◽

Flow Process ◽

Dielectric Relaxation Process ◽

Energy Parameters

The dielectric constant ε´ and dielectric loss ε´´ of the binary mixtures of tetramethylurea (TMU) and chlorobenzene (CB) have been calculated at 9.883 GHz by using standard standing microwave techniques. Gopalakrishna’s single frequency concentration variation method has been used to calculate dipole moment μ and dielectric relaxation time τ for different mole fractions of TMU in the binary mixture at different temperatures of 25 °C, 30 °C, 35 °C, and 40 °C. The variation of dielectric relaxation time with the mole fraction of TMU in the whole concentration range of the binary mixtures was found to be non-monotonic. The solute-solute and solute-solvent type of molecular associations may be proposed based upon above observations. Using Eyring rate equations the energy parameters ΔH, ΔF, and ΔS for the dielectric relaxation process and the viscous flow process have been calculated at the given temperatures. It is found from the comparison of energy parameters that, just like the viscous flow process, the dielectric relaxation process can also be treated as a rate process.

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A New Unified Diffusion—Viscous-Flow Model Based on Pore-Level Studies of Tight Gas Formations

SPE Journal ◽

10.2118/149223-pa ◽

2012 ◽

Vol 18 (01) ◽

pp. 38-49 ◽

Cited By ~ 42

Author(s):

Mohammad R. Rahmanian ◽

Roberto Aguilera ◽

Apostolos Kantzas

Keyword(s):

Porous Media ◽

Viscous Flow ◽

Flow Regime ◽

Gas Flow ◽

Flow Model ◽

Molecular Flow ◽

Single Element ◽

Free Molecular Flow ◽

Flow Through ◽

Tight Porous Media

Summary In this study, single-phase gas-flow simulation that considers slippage effects through a network of slots and microfractures is presented. The statistical parameters for network construction were extracted from petrographic work in tight porous media of the Nikanassin Group in the Western Canada Sedimentary Basin (WCSB). Furthermore, correlations between Klinkenberg slippage effect and absolute permeability have been developed as well as a new unified flow model in which Knudsen number acts implicitly as a flow-regime indicator. A detailed understanding of fluid flow at microscale levels in tight porous media is essential to establish and develop techniques for economic flow rate and recovery. Choosing an appropriate equation for flow through a single element of the network is crucial; this equation must include geometry and other structural features that affect the flow as well as all variation of fluid properties with pressure. Disregarding these details in a single element of porous media can easily lead to flow misinterpretation at the macroscopic scale. Because of the wide flow-path-size distribution in tight porous media, a variety of flow regimes can exist in the equivalent network. Two distinct flow regimes, viscous flow and free molecular flow, are in either side of this flow-regime spectrum. Because the nature of these two types of flow is categorically different, finding/adjusting a unified flow model is problematic. The complication stems from the fact that the viscosity concept misses its meaning as the flow regime changes from viscous to free molecular flow in which a diffusion-like mechanism dominates. For each specified flow regime, the appropriate equations for different geometries are studied. In addition, different unified flow models available in the literature are critically investigated. Simulation of gas flow through the constructed network at different mean flow pressures leads to investigating the functionality of the Klinkenberg factor with permeability of the porous media and pore-level structure.

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Long-term Temporal Variation of Mean Residence Time in Spring and Groundwater After Thinning at a Forested Headwater Catchment

10.5194/egusphere-egu2020-6522 ◽

2020 ◽

Author(s):

Isabela Silveira Baptista ◽

Maki Tsujimura ◽

Yuichi Onda

Keyword(s):

Temporal Variation ◽

Residence Time ◽

Mean Residence Time ◽

Flow Model ◽

Dispersion Model ◽

Spring Water ◽

Groundwater Storage ◽

Flow Process ◽

Piston Flow ◽

The Mean

Treatments on plantation forests, such as thinning, have a significant effect on the quality and quantity of water resources in the watersheds in Japan. However, few studies have performed intensive observations regarding the effects of thinning on the groundwater flow process with combined use of tracers, specially over a long period of time.In this study, stable isotope analysis and hydrological observations were applied to investigate the temporal variation of spring water and groundwater mean residence time in a small watershed at Mount Karasawa, Tochigi Prefecture, Japan. We have monitored the research area since 2010, with periodical sampling once a month for 9 years, with a lack of data in some years after the thinning. &#160;We analyzed the date for three different time periods, those are: Before Thinning, from July 2010 to September 2011, Soon After Thinning, from November 2011 to October 2013 and Long After Thinning, from September 2017 to August 2019.The mean residence time of spring water and groundwater were evaluated by using the stable isotopes of hydrogen and oxygen as tracers, then estimating their d-excess variations using two Lumped-Parameter Models, Exponential-Piston Flow Model and Dispersion Model. The SF6 concentrations were used as an Apparent Age analysis for determination of the model&#8217;s parameters. Both models show a tendency of the mean residence time getting older Soon After Thinning and then getting younger again Long After Thinning.According to a selection of the best model for this area, the Exponential-Piston Flow Model shows that the spring water mean residence time was 25 months Before Thinning, 30 months Soon After Thinning and 26 months Long After Thinning; the groundwater at 15m deep mean residence time was 39 months Before Thinning, 46 months Soon After Thinning and 38 months Long After Thinning and the groundwater at 30m deep mean residence time was 38 months Before Thinning, 47 months Soon After Thinning and 45 months Long After Thinning. These results suggest that Soon After Thinning there is a reduction of forest interception and tree evapotranspiration, leading to an increase in infiltration and groundwater storage. Then, Long After Thinning, the forest interception and tree evapotranspiration rise back again with the recovery of the understory vegetation, which leads to a decrease in infiltration and groundwater storage.

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