MT3D was first developed by Chunmiao Zheng in 1990 at S.S. Papadopulos & Associates, Inc. with partial support from the U.S. Environmental Protection Agency (USEPA). Starting in 1990, MT3D was released as a pubic domain code from the USEPA. Commercial versions with enhanced capab...
Bailey, Ryan T.; Morway, Eric D.; Niswonger, Richard G.; Gates, Timothy K.
2013-01-01
A numerical model was developed that is capable of simulating multispecies reactive solute transport in variably saturated porous media. This model consists of a modified version of the reactive transport model RT3D (Reactive Transport in 3 Dimensions) that is linked to the Unsaturated-Zone Flow (UZF1) package and MODFLOW. Referred to as UZF-RT3D, the model is tested against published analytical benchmarks as well as other published contaminant transport models, including HYDRUS-1D, VS2DT, and SUTRA, and the coupled flow and transport modeling system of CATHY and TRAN3D. Comparisons in one-dimensional, two-dimensional, and three-dimensional variably saturated systems are explored. While several test cases are included to verify the correct implementation of variably saturated transport in UZF-RT3D, other cases are included to demonstrate the usefulness of the code in terms of model run-time and handling the reaction kinetics of multiple interacting species in variably saturated subsurface systems. As UZF1 relies on a kinematic-wave approximation for unsaturated flow that neglects the diffusive terms in Richards equation, UZF-RT3D can be used for large-scale aquifer systems for which the UZF1 formulation is reasonable, that is, capillary-pressure gradients can be neglected and soil parameters can be treated as homogeneous. Decreased model run-time and the ability to include site-specific chemical species and chemical reactions make UZF-RT3D an attractive model for efficient simulation of multispecies reactive transport in variably saturated large-scale subsurface systems.
Bailey, Ryan T; Morway, Eric D; Niswonger, Richard G; Gates, Timothy K
2013-01-01
A numerical model was developed that is capable of simulating multispecies reactive solute transport in variably saturated porous media. This model consists of a modified version of the reactive transport model RT3D (Reactive Transport in 3 Dimensions) that is linked to the Unsaturated-Zone Flow (UZF1) package and MODFLOW. Referred to as UZF-RT3D, the model is tested against published analytical benchmarks as well as other published contaminant transport models, including HYDRUS-1D, VS2DT, and SUTRA, and the coupled flow and transport modeling system of CATHY and TRAN3D. Comparisons in one-dimensional, two-dimensional, and three-dimensional variably saturated systems are explored. While several test cases are included to verify the correct implementation of variably saturated transport in UZF-RT3D, other cases are included to demonstrate the usefulness of the code in terms of model run-time and handling the reaction kinetics of multiple interacting species in variably saturated subsurface systems. As UZF1 relies on a kinematic-wave approximation for unsaturated flow that neglects the diffusive terms in Richards equation, UZF-RT3D can be used for large-scale aquifer systems for which the UZF1 formulation is reasonable, that is, capillary-pressure gradients can be neglected and soil parameters can be treated as homogeneous. Decreased model run-time and the ability to include site-specific chemical species and chemical reactions make UZF-RT3D an attractive model for efficient simulation of multispecies reactive transport in variably saturated large-scale subsurface systems. PMID:23131109
Moving from Batch to Field Using the RT3D Reactive Transport Modeling System
NASA Astrophysics Data System (ADS)
Clement, T. P.; Gautam, T. R.
2002-12-01
The public domain reactive transport code RT3D (Clement, 1997) is a general-purpose numerical code for solving coupled, multi-species reactive transport in saturated groundwater systems. The code uses MODFLOW to simulate flow and several modules of MT3DMS to simulate the advection and dispersion processes. RT3D employs the operator-split strategy which allows the code solve the coupled reactive transport problem in a modular fashion. The coupling between reaction and transport is defined through a separate module where the reaction equations are specified. The code supports a versatile user-defined reaction option that allows users to define their own reaction system through a Fortran-90 subroutine, known as the RT3D-reaction package. Further a utility code, known as BATCHRXN, allows the users to independently test and debug their reaction package. To analyze a new reaction system at a batch scale, users should first run BATCHRXN to test the ability of their reaction package to model the batch data. After testing, the reaction package can simply be ported to the RT3D environment to study the model response under 1-, 2-, or 3-dimensional transport conditions. This paper presents example problems that demonstrate the methods for moving from batch to field-scale simulations using BATCHRXN and RT3D codes. The first example describes a simple first-order reaction system for simulating the sequential degradation of Tetrachloroethene (PCE) and its daughter products. The second example uses a relatively complex reaction system for describing the multiple degradation pathways of Tetrachloroethane (PCA) and its daughter products. References 1) Clement, T.P, RT3D - A modular computer code for simulating reactive multi-species transport in 3-Dimensional groundwater aquifers, Battelle Pacific Northwest National Laboratory Research Report, PNNL-SA-28967, September, 1997. Available at: http://bioprocess.pnl.gov/rt3d.htm.
An implicit dispersive transport algorithm for the US Geological Survey MOC3D solute-transport model
Kipp, K.L., Jr.; Konikow, L.F.; Hornberger, G.Z.
1998-01-01
This report documents an extension to the U.S. Geological Survey MOC3D transport model that incorporates an implicit-in-time difference approximation for the dispersive transport equation, including source/sink terms. The original MOC3D transport model (Version 1) uses the method of characteristics to solve the transport equation on the basis of the velocity field. The original MOC3D solution algorithm incorporates particle tracking to represent advective processes and an explicit finite-difference formulation to calculate dispersive fluxes. The new implicit procedure eliminates several stability criteria required for the previous explicit formulation. This allows much larger transport time increments to be used in dispersion-dominated problems. The decoupling of advective and dispersive transport in MOC3D, however, is unchanged. With the implicit extension, the MOC3D model is upgraded to Version 2. A description of the numerical method of the implicit dispersion calculation, the data-input requirements and output options, and the results of simulator testing and evaluation are presented. Version 2 of MOC3D was evaluated for the same set of problems used for verification of Version 1. These test results indicate that the implicit calculation of Version 2 matches the accuracy of Version 1, yet is more efficient than the explicit calculation for transport problems that are characterized by a grid Peclet number less than about 1.0.
PHT3D-UZF: A reactive transport model for variably-saturated porous media
Wu, Ming Zhi; Post, Vincent E. A.; Salmon, S. Ursula; Morway, Eric; Prommer, H.
2016-01-01
A modified version of the MODFLOW/MT3DMS-based reactive transport model PHT3D was developed to extend current reactive transport capabilities to the variably-saturated component of the subsurface system and incorporate diffusive reactive transport of gaseous species. Referred to as PHT3D-UZF, this code incorporates flux terms calculated by MODFLOW's unsaturated-zone flow (UZF1) package. A volume-averaged approach similar to the method used in UZF-MT3DMS was adopted. The PHREEQC-based computation of chemical processes within PHT3D-UZF in combination with the analytical solution method of UZF1 allows for comprehensive reactive transport investigations (i.e., biogeochemical transformations) that jointly involve saturated and unsaturated zone processes. Intended for regional-scale applications, UZF1 simulates downward-only flux within the unsaturated zone. The model was tested by comparing simulation results with those of existing numerical models. The comparison was performed for several benchmark problems that cover a range of important hydrological and reactive transport processes. A 2D simulation scenario was defined to illustrate the geochemical evolution following dewatering in a sandy acid sulfate soil environment. Other potential applications include the simulation of biogeochemical processes in variably-saturated systems that track the transport and fate of agricultural pollutants, nutrients, natural and xenobiotic organic compounds and micropollutants such as pharmaceuticals, as well as the evolution of isotope patterns.
PHT3D-UZF: A Reactive Transport Model for Variably-Saturated Porous Media.
Wu, Ming Zhi; Post, Vincent E A; Salmon, S Ursula; Morway, Eric D; Prommer, Henning
2016-01-01
A modified version of the MODFLOW/MT3DMS-based reactive transport model PHT3D was developed to extend current reactive transport capabilities to the variably-saturated component of the subsurface system and incorporate diffusive reactive transport of gaseous species. Referred to as PHT3D-UZF, this code incorporates flux terms calculated by MODFLOW's unsaturated-zone flow (UZF1) package. A volume-averaged approach similar to the method used in UZF-MT3DMS was adopted. The PHREEQC-based computation of chemical processes within PHT3D-UZF in combination with the analytical solution method of UZF1 allows for comprehensive reactive transport investigations (i.e., biogeochemical transformations) that jointly involve saturated and unsaturated zone processes. Intended for regional-scale applications, UZF1 simulates downward-only flux within the unsaturated zone. The model was tested by comparing simulation results with those of existing numerical models. The comparison was performed for several benchmark problems that cover a range of important hydrological and reactive transport processes. A 2D simulation scenario was defined to illustrate the geochemical evolution following dewatering in a sandy acid sulfate soil environment. Other potential applications include the simulation of biogeochemical processes in variably-saturated systems that track the transport and fate of agricultural pollutants, nutrients, natural and xenobiotic organic compounds and micropollutants such as pharmaceuticals, as well as the evolution of isotope patterns. PMID:25628017
Ozone formation during an episode over Europe: A 3-D chemical/transport model simulation
NASA Technical Reports Server (NTRS)
Berntsen, Terje; Isaksen, Ivar S. A.
1994-01-01
A 3-D regional photochemical tracer/transport model for Europe and the Eastern Atlantic has been developed based on the NASA/GISS CTM. The model resolution is 4x5 degrees latitude and longitude with 9 layers in the vertical (7 in the troposphere). Advective winds, convection statistics and other meteorological data from the NASA/GISS GCM are used. An extensive gas-phase chemical scheme based on the scheme used in our global 2D model has been incorporated in the 3D model. In this work ozone formation in the troposphere is studied with the 3D model during a 5 day period starting June 30. Extensive local ozone production is found and the relationship between the source regions and the downwind areas are discussed. Variations in local ozone formation as a function of total emission rate, as well as the composition of the emissions (HC/NO(x)) ratio and isoprene emissions) are elucidated. An important vertical transport process in the troposphere is by convective clouds. The 3D model includes an explicit parameterization of this process. It is shown that this process has significant influence on the calculated surface ozone concentrations.
Edge Transport Modeling using the 3D EMC3-Eirene code on Tokamaks and Stellarators
NASA Astrophysics Data System (ADS)
Lore, J. D.; Ahn, J. W.; Briesemeister, A.; Ferraro, N.; Labombard, B.; McLean, A.; Reinke, M.; Shafer, M.; Terry, J.
2015-11-01
The fluid plasma edge transport code EMC3-Eirene has been applied to aid data interpretation and understanding the results of experiments with 3D effects on several tokamaks. These include applied and intrinsic 3D magnetic fields, 3D plasma facing components, and toroidally and poloidally localized heat and particle sources. On Alcator C-Mod, a series of experiments explored the impact of toroidally and poloidally localized impurity gas injection on core confinement and asymmetries in the divertor fluxes, with the differences between the asymmetry in L-mode and H-mode qualitatively reproduced in the simulations due to changes in the impurity ionization in the private flux region. Modeling of NSTX experiments on the effect of 3D fields on detachment matched the trend of a higher density at which the detachment occurs when 3D fields are applied. On DIII-D, different magnetic field models were used in the simulation and compared against the 2D Thomson scattering diagnostic. In simulating each device different aspects of the code model are tested pointing to areas where the model must be further developed. The application to stellarator experiments will also be discussed. Work supported by U.S. DOE: DE-AC05-00OR22725, DE AC02-09CH11466, DE-FC02-99ER54512, and DE-FC02-04ER54698.
Quasi 3D modeling of water flow and solute transport in vadose zone and groundwater
NASA Astrophysics Data System (ADS)
Yakirevich, A.; Kuznetsov, M.; Weisbrod, N.; Pachepsky, Y. A.
2013-12-01
The complexity of subsurface flow systems calls for a variety of concepts leading to the multiplicity of simplified flow models. One commonly used simplification is based on the assumption that lateral flow and transport in unsaturated zone is insignificant unless the capillary fringe is involved. In such cases the flow and transport in the unsaturated zone above groundwater level can be simulated as a 1D phenomenon, whereas through groundwater they are viewed as 2D or 3D phenomena. A new approach for a numerical scheme for 3D variably saturated flow and transport is presented. A Quasi-3D approach allows representing flow in the 'vadose zone - aquifer' system by a series of 1D Richards' equations solved in variably-saturated zone and by 3D-saturated flow equation in groundwater (modified MODFLOW code). The 1D and 3D equations are coupled at the phreatic surface in a way that aquifer replenishment is calculated using the Richards' equation, and solving for the moving water table does not require definition of the specific yield parameter. The 3D advection-dispersion equation is solved in the entire domain by the MT3D code. Using implicit finite differences approximation to couple processes in the vadose zone and groundwater provides mass conservation and increase of computational efficiency. The above model was applied to simulate the impact of irrigation on groundwater salinity in the Alto Piura aquifer (Northern Peru). Studies on changing groundwater quality in arid and semi-arid lands show that irrigation return flow is one of the major factors contributing to aquifer salinization. Existing mathematical models do not account explicitly for the solute recycling during irrigation on a daily scale. Recycling occurs throughout the unsaturated and saturated zones, as function of the solute mass extracted from pumping wells. Salt concentration in irrigation water is calculated at each time step as a function of concentration of both surface water and groundwater
Ash3d: A finite-volume, conservative numerical model for ash transport and tephra deposition
Schwaiger, Hans F.; Denlinger, Roger P.; Mastin, Larry G.
2012-01-01
We develop a transient, 3-D Eulerian model (Ash3d) to predict airborne volcanic ash concentration and tephra deposition during volcanic eruptions. This model simulates downwind advection, turbulent diffusion, and settling of ash injected into the atmosphere by a volcanic eruption column. Ash advection is calculated using time-varying pre-existing wind data and a robust, high-order, finite-volume method. Our routine is mass-conservative and uses the coordinate system of the wind data, either a Cartesian system local to the volcano or a global spherical system for the Earth. Volcanic ash is specified with an arbitrary number of grain sizes, which affects the fall velocity, distribution and duration of transport. Above the source volcano, the vertical mass distribution with elevation is calculated using a Suzuki distribution for a given plume height, eruptive volume, and eruption duration. Multiple eruptions separated in time may be included in a single simulation. We test the model using analytical solutions for transport. Comparisons of the predicted and observed ash distributions for the 18 August 1992 eruption of Mt. Spurr in Alaska demonstrate to the efficacy and efficiency of the routine.
MODIS volcanic ash retrievals vs FALL3D transport model: a quantitative comparison
NASA Astrophysics Data System (ADS)
Corradini, S.; Merucci, L.; Folch, A.
2010-12-01
Satellite retrievals and transport models represents the key tools to monitor the volcanic clouds evolution. Because of the harming effects of fine ash particles on aircrafts, the real-time tracking and forecasting of volcanic clouds is key for aviation safety. Together with the security reasons also the economical consequences of a disruption of airports must be taken into account. The airport closures due to the recent Icelandic Eyjafjöll eruption caused millions of passengers to be stranded not only in Europe, but across the world. IATA (the International Air Transport Association) estimates that the worldwide airline industry has lost a total of about 2.5 billion of Euro during the disruption. Both security and economical issues require reliable and robust ash cloud retrievals and trajectory forecasting. The intercomparison between remote sensing and modeling is required to assure precise and reliable volcanic ash products. In this work we perform a quantitative comparison between Moderate Resolution Imaging Spectroradiometer (MODIS) retrievals of volcanic ash cloud mass and Aerosol Optical Depth (AOD) with the FALL3D ash dispersal model. MODIS, aboard the NASA-Terra and NASA-Aqua polar satellites, is a multispectral instrument with 36 spectral bands operating in the VIS-TIR spectral range and spatial resolution varying between 250 and 1000 m at nadir. The MODIS channels centered around 11 and 12 micron have been used for the ash retrievals through the Brightness Temperature Difference algorithm and MODTRAN simulations. FALL3D is a 3-D time-dependent Eulerian model for the transport and deposition of volcanic particles that outputs, among other variables, cloud column mass and AOD. Three MODIS images collected the October 28, 29 and 30 on Mt. Etna volcano during the 2002 eruption have been considered as test cases. The results show a general good agreement between the retrieved and the modeled volcanic clouds in the first 300 km from the vents. Even if the
Momentum Transport: 2D and 3D Cloud Resolving Model Simulations
NASA Technical Reports Server (NTRS)
Tao, Wei-Kuo
2001-01-01
The major objective of this study is to investigate the momentum budgets associated with several convective systems that developed during the TOGA COARE IOP (west Pacific warm pool region) and GATE (east Atlantic region). The tool for this study is the improved Goddard Cumulas Ensemble (GCE) model which includes a 3-class ice-phase microphysical scheme, explicit cloud radiative interactive processes and air-sea interactive surface processes. The model domain contains 256 x 256 grid points (with 2 km resolution) in the horizontal and 38 grid points (to a depth of 22 km) in the vertical. The 2D domain has 1024 grid points. The simulations were performed over a 7-day time period (December 19-26, 1992, for TOGA COARE and September 1-7, 1994 for GATE). Cyclic literal boundary conditions are required for this type of long-term integration. Two well organized squall systems (TOGA, COARE February 22, 1993, and GATE September 12, 1994) were also simulated using the 3D GCE model. Only 9 h simulations were required to cover the life time of the squall systems. the lateral boundary conditions were open for these two squall systems simulations. the following will be examined: (1) the momentum budgets in the convective and stratiform regions, (2) the relationship between momentum transport and cloud organization (i.e., well organized squall lines versus less organized convective), (3) the differences and similarities in momentum transport between 2D and 3D simulated convective systems, and (4) the differences and similarities in momentum budgets between cloud systems simulated with open and cyclic lateral boundary conditions. Preliminary results indicate that there are only small differences between 2D and 3D simulated momentum budgets. Major differences occur, however, between momentum budgets associated with squall systems simulated using different lateral boundary conditions.
OS3D/GIMRT software for modeling multicomponent-multidimensional reactive transport
CI Steefel; SB Yabusaki
2000-05-17
OS3D/GIMRT is a numerical software package for simulating multicomponent reactive transport in porous media. The package consists of two principal components: (1) the code OS3D (Operator Splitting 3-Dimensional Reactive Transport) which simulates reactive transport by either splitting the reaction and transport steps in time, i.e., the classic time or operator splitting approach, or by iterating sequentially between reactions and transport, and (2) the code GIMRT (Global Implicit Multicomponent Reactive Transport) which treats up to two dimensional reactive transport with a one step or global implicit approach. Although the two codes do not yet have totally identical capabilities, they can be run from the same input file, allowing comparisons to be made between the two approaches in many cases. The advantages and disadvantages of the two approaches are discussed more fully below, but in general OS3D is designed for simulation of transient concentration fronts, particularly under high Peclet number transport conditions, because of its use of a total variation diminishing or TVD transport algorithm. GIMRT is suited for simulating water-rock alteration over long periods of time where the aqueous concentration field is at or close to a quasi-stationary state and the numerical transport errors are less important. Where water-rock interaction occurs over geological periods of time, GIMRT may be preferable to OS3D because of its ability to take larger time steps.
NASA Technical Reports Server (NTRS)
Strahan, Susan E.; Douglass, Anne R.; Einaudi, Franco (Technical Monitor)
2001-01-01
The Global Modeling Initiative (GMI) Team developed objective criteria for model evaluation in order to identify the best representation of the stratosphere. This work created a method to quantitatively and objectively discriminate between different models. In the original GMI study, 3 different meteorological data sets were used to run an offline chemistry and transport model (CTM). Observationally-based grading criteria were derived and applied to these simulations and various aspects of stratospheric transport were evaluated; grades were assigned. Here we report on the application of the GMI evaluation criteria to CTM simulations integrated with a new assimilated wind data set and a new general circulation model (GCM) wind data set. The Finite Volume Community Climate Model (FV-CCM) is a new GCM developed at Goddard which uses the NCAR CCM physics and the Lin and Rood advection scheme. The FV-Data Assimilation System (FV-DAS) is a new data assimilation system which uses the FV-CCM as its core model. One year CTM simulations of 2.5 degrees longitude by 2 degrees latitude resolution were run for each wind data set. We present the evaluation of temperature and annual transport cycles in the lower and middle stratosphere in the two new CTM simulations. We include an evaluation of high latitude transport which was not part of the original GMI criteria. Grades for the new simulations will be compared with those assigned during the original GMT evaluations and areas of improvement will be identified.
The arctic winter stratosphere: simulated with a 3-D chemistry transport model
NASA Astrophysics Data System (ADS)
van den Broek, Martina Maria Petronella
2004-10-01
During the past two decades, the ozone layer has developed a “hole” each winter and spring above the Antarctic continent. Also in cold Arctic winters substantial stratospheric ozone depletion has been measured, although less than in the Antarctic stratosphere. In the Arctic winter stratosphere, the amount of ozone depletion varies interannually and within one winter, depending on polar vortex stability and temperature. The simulation of transport and chemical conversion of ozone and related species requires a three-dimensional (3D) chemistry transport model (CTM), because of the non-symmetric behaviour of the Arctic polar vortex. This thesis reports on several studies of the Arctic winter stratosphere carried out with such a CTM, using off-line meteorological fields. In Chapter II, chlorine activation and ozone depletion in the Arctic winter stratosphere of 1996-1997 are modelled with the newly developed stratospheric version of our CTM. Comparisons have been made with total O3 columns and ClO concentrations observed by satellites, and with ozone loss rates derived from observations during February and March 1997. ClO concentrations and ozone depletion are somewhat underestimated by the model. Key model parameters have been varied to explain this underestimation. Next to temperature, the formation mechanism of solid and/or liquid PSC particles constitutes the main model uncertainty. The representation of tracer transport is a third uncertain parameter, influencing both ozone and inorganic chlorine. In Chapter III, we have used the CTM with different horizontal resolutions to evaluate this stratospheric transport by simulating the long-lived tracers HF and CH4 during the Arctic winter of 1999/2000. Outside the vortex the model results agree well with the observations, but inside, the model underestimates the observed vertical gradient in HF and CH4. Too strong mixing through the vortex edge could be a cause for these model discrepancies, e.g. associated with the
NASA Astrophysics Data System (ADS)
Hostache, Renaud; Krein, Andreas; Barrière, Julien
2014-05-01
Coupling the 3D hydro-morphodynamic model Telemac-3D-sisyphe and seismic measurements to estimate bedload transport rates in a small gravel-bed river. Renaud Hostache, Andreas Krein, Julien Barrière During flood events, amounts of river bed material are transported via bedload. This causes problems, like the silting of reservoirs or the disturbance of biological habitats. Some current bedload measuring techniques have limited possibilities for studies in high temporal resolutions. Optical systems are usually not applicable because of high turbidity due to concentrated suspended sediment transported. Sediment traps or bedload samplers yield only summative information on bedload transport with low temporal resolution. An alternative bedload measuring technique is the use of seismological systems installed next to the rivers. The potential advantages are observations in real time and under undisturbed conditions. The study area is a 120 m long reach of River Colpach (21.5 km2), a small gravel bed river in Northern Luxembourg. A combined approach of hydro-climatological observations, hydraulic measurements, sediment sampling, and seismological measurements is used in order to investigate bedload transport phenomena. Information derived from seismic measurements and results from a 3-dimensional hydro-morphodynamic model are exemplarily discussed for a November 2013 flood event. The 3-dimensional hydro-morphodynamic model is based on the Telemac hydroinformatic system. This allows for dynamically coupling a 3D hydrodynamic model (Telemac-3D) and a morphodynamic model (Sisyphe). The coupling is dynamic as these models exchange their information during simulations. This is a main advantage as it allows for taking into account the effects of the morphologic changes of the riverbed on the water hydrodynamic and the bedload processes. The coupled model has been calibrated using time series of gauged water depths and time series of bed material collected sequentially (after
3D modelling of the transport and fate of riverine fine sediment exported to a semi-enclosed system
NASA Astrophysics Data System (ADS)
Delandmeter, Philippe; Lambrechts, Jonathan; Lewis, Stephen; Legat, Vincent; Deleersnijder, Eric; Wolanski, Eric
2015-04-01
Understanding the transport and fate of suspended sediment exported by rivers is crucial for the management of sensitive marine ecosystems. Sediment transport and fate can vary considerably depending on the geophysical characteristics of the offshore environment (i.e. open, semi-enclosed and enclosed systems and the nature of the continental shelf). In this presentation, we focus on a semi-enclosed setting in the Great Barrier Reef, NE Australia. In this system, the large tropical Burdekin River discharges to a long and narrow continental shelf containing numerous headlands and embayments. Using a new 3D sediment model we developed and SLIM 3D, a Finite Element 3D model for coastal flows, we highlight the key processes of sediment transport for such a system. We validate the model with available measured data from the region. Wind direction and speed during the high river flows are showed to largely control the dynamics and final fate of the sediments. Most (71%) of the sediment load delivered by the river is deposited and retained near the river mouth. The remaining sediment is transported further afield in riverine freshwater plumes. The suspended sediment transported longer distances in the freshwater plumes can reach sensitive marine ecosystems. These results are compared to previous studies on the Burdekin River sediment fate and differences are analysed. The model suggests that wind-driven resuspension events will redistribute sediments within an embayment but have little influence on transporting sediments from bay to bay.
Estimation of Atmospheric Methane Surface Fluxes Using a Global 3-D Chemical Transport Model
NASA Astrophysics Data System (ADS)
Chen, Y.; Prinn, R.
2003-12-01
Accurate determination of atmospheric methane surface fluxes is an important and challenging problem in global biogeochemical cycles. We use inverse modeling to estimate annual, seasonal, and interannual CH4 fluxes between 1996 and 2001. The fluxes include 7 time-varying seasonal (3 wetland, rice, and 3 biomass burning) and 3 steady aseasonal (animals/waste, coal, and gas) global processes. To simulate atmospheric methane, we use the 3-D chemical transport model MATCH driven by NCEP reanalyzed observed winds at a resolution of T42 ( ˜2.8° x 2.8° ) in the horizontal and 28 levels (1000 - 3 mb) in the vertical. By combining existing datasets of individual processes, we construct a reference emissions field that represents our prior guess of the total CH4 surface flux. For the methane sink, we use a prescribed, annually-repeating OH field scaled to fit methyl chloroform observations. MATCH is used to produce both the reference run from the reference emissions, and the time-dependent sensitivities that relate individual emission processes to observations. The observational data include CH4 time-series from ˜15 high-frequency (in-situ) and ˜50 low-frequency (flask) observing sites. Most of the high-frequency data, at a time resolution of 40-60 minutes, have not previously been used in global scale inversions. In the inversion, the high-frequency data generally have greater weight than the weekly flask data because they better define the observational monthly means. The Kalman Filter is used as the optimal inversion technique to solve for emissions between 1996-2001. At each step in the inversion, new monthly observations are utilized and new emissions estimates are produced. The optimized emissions represent deviations from the reference emissions that lead to a better fit to the observations. The seasonal processes are optimized for each month, and contain the methane seasonality and interannual variability. The aseasonal processes, which are less variable, are
NASA Astrophysics Data System (ADS)
Daughney, C.; Toews, M. W.; Morgenstern, U.; Cornaton, F. J.; Jackson, B. M.
2013-12-01
Lake Rotorua is a focus of culture and tourism in New Zealand. The lake's water quality has declined since the 1970s, partly due to nutrient inputs that reach the lake via the groundwater system. Improved land use management within the catchment requires prediction of the spatial variations of groundwater transit time from land surface to the lake, and from this the prediction of current and future nutrient inflows to the lake. This study combines the two main methods currently available for determination of water age: numerical groundwater models and hydrological tracers. A steady-state 3D finite element model was constructed to simulate groundwater flow and transport of tritium and age at the catchment scale (555 km2). The model materials were defined using a 3D geologic model and included ignimbrites, rhyolites, alluvial and lake bottom sediments. The steady-state saturated groundwater flow model was calibrated using observed groundwater levels in boreholes (111 locations) and stream flow measurements from groundwater-fed streams and springs (61 locations). Hydraulic conductivities and Cauchy boundary conditions associated with the streams, springs and lake were parameterized. The transport parameters for the model were calibrated using 191 tritium samples from 105 locations (springs, streams and boreholes), with most locations having two sample dates. The transport model used steady-state flow, but simulated the transient transport and decay of tritium from rainfall recharge between 1945 and 2012. An additional 1D unsaturated sub-model was added to account for tritium decay from the ground surface to the water table. The sub-model is linked on top of the 3D model, and uses the water table depths and material properties from the 3D model. The adjustable calibration parameters for the transport model were porosity and van Genuchten parameters related to the unsaturated sub-models. Calibration of the flow model was achieved using a combination of automated least
NASA Astrophysics Data System (ADS)
Teruzzi, Anna; Dobricic, Srdjan; Solidoro, Cosimo; Cossarini, Gianpiero
2014-01-01
Increasing attention is dedicated to the implementation of suitable marine forecast systems for the estimate of the state of the ocean. Within the framework of the European MyOcean infrastructure, the pre-existing short-term Mediterranean Sea biogeochemistry operational forecast system has been upgraded by assimilating remotely sensed ocean color data in the coupled transport-biogeochemical model OPATM-BFM using a 3-D variational data assimilation (3D-VAR) procedure. In the present work, the 3D-VAR scheme is used to correct the four phytoplankton functional groups included in the OPATM-BFM in the period July 2007 to September 2008. The 3D-VAR scheme decomposes the error covariance matrix using a sequence of different operators that account separately for vertical covariance, horizontal covariance, and covariance among biogeochemical variables. The assimilation solution is found in a reduced dimensional space, and the innovation for the biogeochemical variables is obtained by the sequential application of the covariance operators. Results show a general improvement in the forecast skill, providing a correction of the basin-scale bias of surface chlorophyll concentration and of the local-scale spatial and temporal dynamics of typical bloom events. Further, analysis of the assimilation skill provides insights into the functioning of the model. The computational costs of the assimilation scheme adopted are low compared to other assimilation techniques, and its modular structure facilitates further developments. The 3D-VAR scheme results especially suitable for implementation within a biogeochemistry operational forecast system.
A 3D Model for Ion Beam Formation and Transport Simulation
Qiang, J.; Todd, D.; Leitner, D.
2006-02-07
In this paper, we present a three-dimensional model forself-consistently modeling ion beam formation from plasma ion sources andtransporting in low energy beam transport systems. A multi-sectionoverlapped computational domain has been used to break the originaltransport system into a number of weakly coupled subsystems. Within eachsubsystem, macro-particle tracking is used to obtain the charge densitydistribution in this subdomain. The three-dimensional Poisson equation issolved within the subdomain after each particle tracking to obtain theself-consistent space-charge forces and the particle tracking is repeateduntil the solution converges. Two new Poisson solvers based on acombination of the spectral method and the finite difference multigridmethod have been developed to solve the Poisson equation in cylindricalcoordinates for the straight beam transport section and in Frenet-Serretcoordinates for the bending magnet section. This model can have importantapplication in design and optimization of the low energy beam line opticsof the proposed Rare Isotope Accelerator (RIA) front end.
Barlebo, H.C.; Rosbjerg, D.; Hill, M.C.
1996-01-01
An extensive amount of data including hydraulic heads, hydraulic conductivities and concentrations of several solutes from controlled injections have been collected during the MADE 1 and MADE 2 experiments at a heterogeneous site near Columbus, Mississippi. In this paper the use of three-dimensional inverse groundwater models including simultaneous estimation of flow and transport parameters is proposed to help identify the dominant characteristics at the site. Simulations show that using a hydraulic conductivity distribution obtained from 2187 borehole flowmeter tests directly in the model produces poor matches to the measured hydraulic heads and tritium concentrations. Alternatively, time averaged hydraulic head maps are used to define zones of constant hydraulic conductivity to be estimated. Preliminary simulations suggest that in the case of conservative transport many, but not all, of the major plume characteristics can be explained by large-scale heterogeneity in recharge and hydraulic conductivity.
Age, double porosity, and simple reaction modifications for the MOC3D ground-water transport model
Goode, Daniel J.
1999-01-01
This report documents modifications for the MOC3D ground-water transport model to simulate (a) ground-water age transport; (b) double-porosity exchange; and (c) simple but flexible retardation, decay, and zero-order growth reactions. These modifications are incorporated in MOC3D version 3.0. MOC3D simulates the transport of a single solute using the method-ofcharacteristics numerical procedure. The age of ground water, that is the time since recharge to the saturated zone, can be simulated using the transport model with an additional source term of unit strength, corresponding to the rate of aging. The output concentrations of the model are in this case the ages at all locations in the model. Double porosity generally refers to a separate immobilewater phase within the aquifer that does not contribute to ground-water flow but can affect solute transport through diffusive exchange. The solute mass exchange rate between the flowing water in the aquifer and the immobile-water phase is the product of the concentration difference between the two phases and a linear exchange coefficient. Conceptually, double porosity can approximate the effects of dead-end pores in a granular porous media, or matrix diffusion in a fractured-rock aquifer. Options are provided for decay and zero-order growth reactions within the immobilewater phase. The simple reaction terms here extend the original model, which included decay and retardation. With these extensions, (a) the retardation factor can vary spatially within each model layer, (b) the decay rate coefficient can vary spatially within each model layer and can be different for the dissolved and sorbed phases, and (c) a zero-order growth reaction is added that can vary spatially and can be different in the dissolved and sorbed phases. The decay and growth reaction terms also can change in time to account for changing geochemical conditions during transport. The report includes a description of the theoretical basis of the model, a
A 3D transport model study of chlorine activation during EASOE
Chipperfield, M.P.; Cariolle, D.; Simon, P. )
1994-06-22
The authors present the results of a chemical transport model which was applied to the problem of atmospheric chemistry of trace species in the stratosphere during EASOE. The model uses a comprehensive set of gas phase reactions, as well as modeling reactions occuring on nuclei in polar stratospheric clouds. This model has been used to study the development of chlorine compounds during the winter of 1991-92. Meteorological data is used as a boundary condition for the model. Significant increases in reactive chlorine are shown to occur in the lower stratosphere through mid January, when warming reduced the occurrence of polar stratospheric clouds. Even with the enhanced active chlorine presence, the lack of sunlight inhibited substantial chemical destruction of ozone.
NASA Astrophysics Data System (ADS)
Ivy, D. J.; Rigby, M. L.; Prinn, R. G.; Muhle, J.; Weiss, R. F.
2009-12-01
We present optimized annual global emissions from 1973-2008 of nitrogen trifluoride (NF3), a powerful greenhouse gas which is not currently regulated by the Kyoto Protocol. In the past few decades, NF3 production has dramatically increased due to its usage in the semiconductor industry. Emissions were estimated through the 'pulse-method' discrete Kalman filter using both a simple, flexible 2-D 12-box model used in the Advanced Global Atmospheric Gases Experiment (AGAGE) network and the Model for Ozone and Related Tracers (MOZART v4.5), a full 3-D atmospheric chemistry model. No official audited reports of industrial NF3 emissions are available, and with limited information on production, a priori emissions were estimated using both a bottom-up and top-down approach with two different spatial patterns based on semiconductor perfluorocarbon (PFC) emissions from the Emission Database for Global Atmospheric Research (EDGAR v3.2) and Semiconductor Industry Association sales information. Both spatial patterns used in the models gave consistent results, showing the robustness of the estimated global emissions. Differences between estimates using the 2-D and 3-D models can be attributed to transport rates and resolution differences. Additionally, new NF3 industry production and market information is presented. Emission estimates from both the 2-D and 3-D models suggest that either the assumed industry release rate of NF3 or industry production information is still underestimated.
Three-fluid, 3D MHD solar wind modeling with turbulence transport and eddy viscosity
NASA Astrophysics Data System (ADS)
Usmanov, A. V.; Goldstein, M. L.; Matthaeus, W. H.
2014-12-01
We present results from a three-fluid, fully three-dimensional MHD solar wind model that includes turbulence transport, eddy viscosity, turbulent resistivity, and turbulent heating. The solar wind plasma is described as a co-moving system of three species: the solar wind protons, electrons, and interstellar pickup protons. Separate energy equations are employed for each species. We obtain numerical solutions of Reynolds-averaged solar wind equations coupled with turbulence transport equations in the region from 0.3 to 100 AU. The integrated system of equations includes the effects of electron heat conduction, Coulomb collisions, photoionization of interstellar hydrogen atoms and their charge exchange with the solar wind protons, turbulence energy generation by pickup protons, and turbulent heating of solar wind protons and electrons. Using either a dipole approximation for the solar magnetic field or synoptic solar magnetograms from the Wilcox Solar Observatory for assigning boundary conditions at the coronal base, we apply the model to study the global structure of the solar wind and its three-dimensional properties, including turbulence parameters, throughout the heliosphere. The model results are compared with observations on WIND, Ulysses and Voyager 2 spacecraft. This work is partially supported by LWS and Heliophysics Grand Challenges programs.
Teruzzi, Anna; Dobricic, Srdjan; Solidoro, Cosimo; Cossarini, Gianpiero
2014-01-01
[1] Increasing attention is dedicated to the implementation of suitable marine forecast systems for the estimate of the state of the ocean. Within the framework of the European MyOcean infrastructure, the pre-existing short-term Mediterranean Sea biogeochemistry operational forecast system has been upgraded by assimilating remotely sensed ocean color data in the coupled transport-biogeochemical model OPATM-BFM using a 3-D variational data assimilation (3D-VAR) procedure. In the present work, the 3D-VAR scheme is used to correct the four phytoplankton functional groups included in the OPATM-BFM in the period July 2007 to September 2008. The 3D-VAR scheme decomposes the error covariance matrix using a sequence of different operators that account separately for vertical covariance, horizontal covariance, and covariance among biogeochemical variables. The assimilation solution is found in a reduced dimensional space, and the innovation for the biogeochemical variables is obtained by the sequential application of the covariance operators. Results show a general improvement in the forecast skill, providing a correction of the basin-scale bias of surface chlorophyll concentration and of the local-scale spatial and temporal dynamics of typical bloom events. Further, analysis of the assimilation skill provides insights into the functioning of the model. The computational costs of the assimilation scheme adopted are low compared to other assimilation techniques, and its modular structure facilitates further developments. The 3D-VAR scheme results especially suitable for implementation within a biogeochemistry operational forecast system. PMID:26213670
NASA Astrophysics Data System (ADS)
Janssen, G.; Del Val Alonso, L.; Groenendijk, P.; Griffioen, J.
2012-12-01
We developed an on-line coupling between the 1D/quasi-2D nutrient transport model ANIMO and the 3D groundwater transport model code MT3DMS. ANIMO is a detailed, process-oriented model code for the simulation of nitrate leaching to groundwater, N- and P-loads on surface waters and emissions of greenhouse gasses. It is the leading nutrient fate and transport code in the Netherlands where it is used primarily for the evaluation of fertilization related legislation. In addition, the code is applied frequently in international research projects. MT3DMS is probably the most commonly used groundwater solute transport package worldwide. The on-line model coupling ANIMO-MT3DMS combines the state-of-the-art descriptions of the biogeochemical cycles in ANIMO with the advantages of using a 3D approach for the transport through the saturated domain. These advantages include accounting for regional lateral transport, considering groundwater-surface water interactions more explicitly, and the possibility of using MODFLOW to obtain the flow fields. An additional merit of the on-line coupling concept is that it preserves feedbacks between the saturated and unsaturated zone. We tested ANIMO-MT3DMS by simulating nutrient transport for the period 1970-2007 in a Dutch agricultural polder catchment covering an area of 118 km2. The transient groundwater flow field had a temporal resolution of one day and was calculated with MODFLOW-MetaSWAP. The horizontal resolution of the model grid was 100x100m and consisted of 25 layers of varying thickness. To keep computation times manageable, we prepared MT3DMS for parallel computing, which in itself is a relevant development for a large community of groundwater transport modelers. For the parameterization of the soil, we applied a standard classification approach, representing the area by 60 units with unique combinations of soil type, land use and geohydrological setting. For the geochemical parameterization of the deeper subsurface, however, we
NASA Astrophysics Data System (ADS)
Lamorski, Krzysztof; Sławiński, Cezary; Barna, Gyöngyi
2014-05-01
There are some important macroscopic properties of the soil porous media such as: saturated permeability and water retention characteristics. These soil characteristics are very important as they determine soil transport processes and are commonly used as a parameters of general models of soil transport processes used extensively for scientific developments and engineering practise. These characteristics are usually measured or estimated using some statistical or phenomenological modelling, i.e. pedotransfer functions. On the physical basis, saturated soil permeability arises from physical transport processes occurring at the pore level. Current progress in modelling techniques, computational methods and X-ray micro-tomographic technology gives opportunity to use direct methods of physical modelling for pore level transport processes. Physically valid description of transport processes at micro-scale based on Navier-Stokes type modelling approach gives chance to recover macroscopic porous medium characteristics from micro-flow modelling. Water microflow transport processes occurring at the pore level are dependent on the microstructure of porous body and interactions between the fluid and the medium. In case of soils, i.e. the medium there exist relatively big pores in which water can move easily but also finer pores are present in which water transport processes are dominated by strong interactions between the medium and the fluid - full physical description of these phenomena is a challenge. Ten samples of different soils were scanned using X-ray computational microtomograph. The diameter of samples was 5 mm. The voxel resolution of CT scan was 2.5 µm. Resulting 3D soil samples images were used for reconstruction of the pore space for further modelling. 3D image threshholding was made to determine the soil grain surface. This surface was triangulated and used for computational mesh construction for the pore space. Numerical modelling of water flow through the
Development of a 3D to 1D Particle Transport Model to Predict Deposition in the Lungs
NASA Astrophysics Data System (ADS)
Oakes, Jessica M.; Grandmont, Celine; Shadden, Shawn C.; Vignon-Clementel, Irene E.
2014-11-01
Aerosolized particles are commonly used for therapeutic drug delivery as they can be delivered to the body systemically or be used to treat lung diseases. Recent advances in computational resources have allowed for sophisticated pulmonary simulations, however it is currently impossible to solve for airflow and particle transport for all length and time scales of the lung. Instead, multi-scale methods must be used. In our recent work, where computational methods were employed to solve for airflow and particle transport in the rat airways (Oakes et al. (2014), Annals of Biomedical Engineering 42, 899), the number of particles to exit downstream of the 3D domain was determined. In this current work, the time-dependent Lagrangian description of particles was used to numerically solve a 1D convection-diffusion model (trumpet model, Taulbee and Yu (1975), Journal of Applied Physiology, 38, 77) parameterized specifically for the lung. The expansion of the airway dimensions was determined based on data collected from our aerosol exposure experiments (Oakes et al. (2014), Journal of Applied Physiology, 116, 1561). This 3D-1D framework enables us to predict the fate of particles in the whole lung. This work was supported by the Whitaker Foundation at the IIE, a INRIA Associated Team Postdoc Grant, and a UC Presidential Fellowship.
NASA Astrophysics Data System (ADS)
Vitousek, S.; Fletcher, C. H.; Storlazzi, C. D.
2006-12-01
Nearshore currents are driven by a number of components including tides, waves winds and even internal tides. To adequately simulate transport of sand and other constituents, the realistic behavior of the dominant current-generating phenomena should be resolved. This often requires sufficient observations and calibration/validation efforts to achieve realistic modeling results. The work explores the capabilities of modeling the currents along West Maui. The West Maui coast has a propagating tide where the observed peak tidal currents, which are directed parallel to the coast, occur very closely to the peak tidal water levels. In 2003, the USGS collected an extensive set of current observations along West Maui, Hawaii, with the goal of better understanding transport mechanisms of sediment, larvae, pollutants and other particles in coral reef settings. The observations included vessel mounted ADCP surveys and an array seafloor instruments at the 10m isobath along the coast. A simple 2DH model of West Maui using Delft3D shows good comparison of the modeled and observed currents. Nearshore currents driven by waves and winds are also considered. During the data collection period a significant erosion event occurred within the study domain at Kaanapali Beach. This event undermined several trees on the shoreline and threatened resort infrastructure. In modeling the nearshore currents of this region we hope to determine the potential for sand transport and shoreline change to hindcast this event.
NASA Astrophysics Data System (ADS)
Rona, Michael; Gasser, Guy; Negev, Ido; Pankratov, Irena; Elhanany, Sara; Lev, Ovadia; Gvirtzman, Haim
2014-05-01
Wastewater recharge facilities are often used as a final water treatment before the discharge to the sea or before water reclamation. These facilities are often located in active aquifers that supply drinking water. Thus, leakage from the water recharge facility and gradual expansion of the underground wastewater plume are of considerable health concern. Hydrological modeling of water recharge systems are widely used as operational and predictive tools. These models rely on distributed water head monitoring and at least one chemical or physical tracer to model solutes' transport. Refractory micropollutants have proven useful in qualitative identification of pollution leakages and for quantification of pollution to a specific site near water recharge facilities. However, their usefulness as tracers for hydrological modeling is still questionable. In this article, we describe a long term, 3-D hydraulic model of a large-scale wastewater effluents recharge system in which a combination of chloride and a refractory micropollutant, carbamazepine is used to trace the solute transport. The combination of the two tracers provides the model with the benefits of the high specificity of the carbamazepine and the extensive historic data base that is available for chloride. The model predicts westward expansion of the pollution plume, whereas a standing front is formed at the east. These trends can be confirmed by the time trace of the carbamazepine concentrations at specific locations. We show that the combination of two tracers accounts better (at least at some locations) for the evolution of the pollution plume than a model based on chloride or carbamazepine alone.
Reactive transport in 3D models of irregularly fractured rock masses
NASA Astrophysics Data System (ADS)
Driesner, T.; Mindel, J. E.
2014-12-01
Reactive transport through irregularly fractured rock masses is a key phenomenon in ore-forming hydrothermal systems, geothermal systems, and many other geological processes and will affect the mechanical properties and hydraulic apertures of fractures. Realistic representations of such systems have so far been hampered by technical limitations of most hydrothermal reactive transport codes, namely the ability to represent discrete fracture networks in a porous rock matrix. We present the first three-dimensional simulation results obtained from coupling a combined finite element - finite volume scheme of the revised CSMP++ flow simulation platform (1) with the GEMIPM3K (2) chemical equilibration code. In these, we represented fracture zones as thin, porous zones of higher permeability. The simulations demonstrate the effects of fracture zone orientation relative to the pressure field and fracture zone intersections on the differential advance of reaction fronts. We outline our numerical approaches for testing and comparing the effect of various ways of representing fractures and fracture zones in irregular meshes, namely the possibility of using layers of prism elements to represent fractures of finite thickness with internally varying properties and the possibility to represent thin fractures as lower dimensional (=2D) elements. We intend to make use of the "split node" capabilities of CSMP++ (3) to maintain sharp interfaces at material boundaries in order to be able to study the transient influence of reactive flow on fracture and matrix permeability in irregularly fractured rock masses.
ERIC Educational Resources Information Center
Manos, Harry
2016-01-01
Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the "TPT" theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity…
A 3-D Model of Signaling and Transport Pathways in Epithelial Cells
Quong, A A; Westbrook, C K
2005-04-01
A 3-dimensional computer model was developed to simulate the spatial and chemical evolution of calcium ions inside an array of human epithelial kidney cells. This is a prototype model, intended to develop a methodology to incorporate much more complex interactions of metabolic and other processes within many types of cells and lead to increased ability to predict cellular responses to disease as well as to chemical and biological warfare situations. Preliminary tests of the model are described.
Modelling of transport phenomena in 3D GMAW of thick metals with V groove
NASA Astrophysics Data System (ADS)
Hu, J.; Tsai, H. L.
2008-03-01
This paper analyses the dynamic process of groove filling and the resulting weld pool fluid flow in gas metal arc welding of thick metals with V groove. Filler droplets carrying mass, momentum, thermal energy and sulfur species are periodically impinged onto the workpiece. The complex transport phenomena in the weld pool, caused by the combined effect of droplet impingement, gravity, electromagnetic force, surface tension and plasma arc pressure, were investigated to determine the transient weld pool shape and distributions of velocity, temperature and sulfur species in the weld pool. It was found that the groove provides a channel which can smooth the flow in the weld pool, leading to poor mixing between the filler metal and the base metal.
Radiosity diffusion model in 3D
NASA Astrophysics Data System (ADS)
Riley, Jason D.; Arridge, Simon R.; Chrysanthou, Yiorgos; Dehghani, Hamid; Hillman, Elizabeth M. C.; Schweiger, Martin
2001-11-01
We present the Radiosity-Diffusion model in three dimensions(3D), as an extension to previous work in 2D. It is a method for handling non-scattering spaces in optically participating media. We present the extension of the model to 3D including an extension to the model to cope with increased complexity of the 3D domain. We show that in 3D more careful consideration must be given to the issues of meshing and visibility to model the transport of light within reasonable computational bounds. We demonstrate the model to be comparable to Monte-Carlo simulations for selected geometries, and show preliminary results of comparisons to measured time-resolved data acquired on resin phantoms.
Modeling Star-Forming Regions using a 3D Molecular Transport Code
NASA Astrophysics Data System (ADS)
Loughnane, R. M.; Redman, M. P.; Keto, E. R.
2012-07-01
This paper presents the 3-dimensional non-LTE radiative transfer code, MOLLIE (MOLelcular LIne Explorer), for solving molecular and atomic excitation and radiation transfer in a molecular gas and predicting emergent spectra. The code implementation makes use of the Accelerated Lambda Iteration (ALI) method of Rybicki & Hummer (1991) to solve the radiative transfer equation along rays passing through a spherical model cloud. When convergence between level populations, the radiation field, and the point separation has been obtained, the grid is ray-traced to produce images that can be readily compared to observations. The optimization technique, Fast Simulated Annealing (FSA), adopted by MOLLIE to increase the probability of arriving at a satisfactory output in a timely fashion, is briefly considered.
Unsteady Analysis of Particle Transport and Deposition in the Human Lung: A Hybrid 3D/0D Model
NASA Astrophysics Data System (ADS)
Haworth, Daniel C.; Kunz, Robert F.; Leemhuis, Laura S.; Banks, Syreeta S.; Kriete, Andres
2003-11-01
Three-dimensional CFD meshes including up the sixteenth generation of branching in a human tracheo-bronchial tree have been generated from surface data extracted using novel high-resolution bio-medical imaging and rendering methods. A zero-dimensional model for the deeper generations has been coupled with the three-dimensional model at each of the truncated branches. The 0D model imposes a time-varying volume to simulate realistic breathing cycles; it also includes a simple model for particle deposition. The resulting hybrid 3D/0D model has been exercised to compute the transport and deposition rates of particles of different sizes through full breathing cycles. Results are compared to earlier steady-flow CFD results, to results obtained using one-dimensional functional models of the human lung, and to experimental and modeling results for idealized branching-duct configurations. The aim of the research is to develop a virtual human respiratory system that can be used to address issues in pulmonary health in
NASA Astrophysics Data System (ADS)
Manos, Harry
2016-03-01
Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the TPT theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity well tailored to specific class lessons. Most of the supplies are readily available in the home or at school: rubbing alcohol, a rag, two colors of spray paint, art brushes, and masking tape. The cost of these supplies, if you don't have them, is less than 20.
3D Multigroup Sn Neutron Transport Code
2001-02-14
ATTILA is a 3D multigroup transport code with arbitrary order ansotropic scatter. The transport equation is solved in first order form using a tri-linear discontinuous spatial differencing on an arbitrary tetrahedral mesh. The overall solution technique is source iteration with DSA acceleration of the scattering source. Anisotropic boundary and internal sources may be entered in the form of spherical harmonics moments. Alpha and k eigenvalue problems are allowed, as well as fixed source problems. Forwardmore » and adjoint solutions are available. Reflective, vacumn, and source boundary conditions are available. ATTILA can perform charged particle transport calculations using slowing down (CSD) terms. ATTILA can also be used to peform infra-red steady-state calculations for radiative transfer purposes.« less
3D Multigroup Sn Neutron Transport Code
McGee, John; Wareing, Todd; Pautz, Shawn
2001-02-14
ATTILA is a 3D multigroup transport code with arbitrary order ansotropic scatter. The transport equation is solved in first order form using a tri-linear discontinuous spatial differencing on an arbitrary tetrahedral mesh. The overall solution technique is source iteration with DSA acceleration of the scattering source. Anisotropic boundary and internal sources may be entered in the form of spherical harmonics moments. Alpha and k eigenvalue problems are allowed, as well as fixed source problems. Forward and adjoint solutions are available. Reflective, vacumn, and source boundary conditions are available. ATTILA can perform charged particle transport calculations using slowing down (CSD) terms. ATTILA can also be used to peform infra-red steady-state calculations for radiative transfer purposes.
NASA Technical Reports Server (NTRS)
Strahan, Susan E.; Douglass, Anne R.
2003-01-01
The Global Modeling Initiative has integrated two 35-year simulations of an ozone recovery scenario with an offline chemistry and transport model using two different meteorological inputs. Physically based diagnostics, derived from satellite and aircraft data sets, are described and then used to evaluate the realism of temperature and transport processes in the simulations. Processes evaluated include barrier formation in the subtropics and polar regions, and extratropical wave-driven transport. Some diagnostics are especially relevant to simulation of lower stratospheric ozone, but most are applicable to any stratospheric simulation. The temperature evaluation, which is relevant to gas phase chemical reactions, showed that both sets of meteorological fields have near climatological values at all latitudes and seasons at 30 hPa and below. Both simulations showed weakness in upper stratospheric wave driving. The simulation using input from a general circulation model (GMI(sub GCM)) showed a very good residual circulation in the tropics and northern hemisphere. The simulation with input from a data assimilation system (GMI(sub DAS)) performed better in the midlatitudes than at high latitudes. Neither simulation forms a realistic barrier at the vortex edge, leading to uncertainty in the fate of ozone-depleted vortex air. Overall, tracer transport in the offline GMI(sub GCM) has greater fidelity throughout the stratosphere than the GMI(sub DAS).
Crowdsourcing Based 3d Modeling
NASA Astrophysics Data System (ADS)
Somogyi, A.; Barsi, A.; Molnar, B.; Lovas, T.
2016-06-01
Web-based photo albums that support organizing and viewing the users' images are widely used. These services provide a convenient solution for storing, editing and sharing images. In many cases, the users attach geotags to the images in order to enable using them e.g. in location based applications on social networks. Our paper discusses a procedure that collects open access images from a site frequently visited by tourists. Geotagged pictures showing the image of a sight or tourist attraction are selected and processed in photogrammetric processing software that produces the 3D model of the captured object. For the particular investigation we selected three attractions in Budapest. To assess the geometrical accuracy, we used laser scanner and DSLR as well as smart phone photography to derive reference values to enable verifying the spatial model obtained from the web-album images. The investigation shows how detailed and accurate models could be derived applying photogrammetric processing software, simply by using images of the community, without visiting the site.
Carafa, R; Marinov, D; Dueri, S; Wollgast, J; Ligthart, J; Canuti, E; Viaroli, P; Zaldívar, J M
2006-10-01
Sacca di Goro is a shallow coastal microtidal lagoon with a surface area of 26 km2, and an average depth of about 1.5m. Fresh water pollutant loads from Po River branches and several drainage canals lead to anthropogenic eutrophication, frequent summer anoxia crises and chemical contamination. Such events not only affect the lagoon ecosystem but also cause serious economic losses, the lagoon being the second largest producer of clams in Italy. The present work aims at using a fate model coupled with COHERENS 3D hydrodynamic model to simulate and to explain the spatial distribution and temporal variations of s-triazines herbicides in the Sacca di Goro lagoon. The simulation results of spatial and temporal dynamic behaviour of atrazine, simazine and terbuthylazine have been compared with experimental data obtained during an annual monitoring programme. PMID:16643962
Modeling of tungsten transport in the linear plasma device PSI-2 with the 3D Monte-Carlo code ERO
NASA Astrophysics Data System (ADS)
Marenkov, E.; Eksaeva, A.; Borodin, D.; Kirschner, A.; Laengner, M.; Kurnaev, V.; Kreter, A.; Coenen, J. W.; Rasinski, M.
2015-08-01
The ERO code was modified for modeling of plasma-surface interactions and impurities transport in the PSI-2 installation. Results of experiments on tungsten target irradiation with argon plasma were taken as a benchmark for the new version of the code. Spectroscopy data modeled with the code are in good agreement with experimental ones. Main factors contributing to observed discrepancies are discussed.
Vandersall, K S; Murty, S S; Chidester, S K; Forbes, J W; Garcia, F; Greenwood, D W; Tarver, C M
2003-07-02
The Steven Impact Test and associated modeling offer valuable practical predictions for evaluating numerous safety scenarios involving low velocity impact of energetic materials by different projectile geometries. One such scenario is the impact of energetic material by a transportation hook during shipping, which offers complexity because of the irregular hook projectile shape. Experiments were performed using gauged Steven Test targets with PBX9404 impacted by a transportation hook projectile to compliment previous non-gauged experiments that established an impact threshold of approximately 69 m/s. Modeling of these experiments was performed with LS-DYNA code using an Ignition and Growth reaction criteria with a friction term. Comparison of the experiment to the model shows reasonable agreement with some details requiring more attention. The experimental results (including carbon resistor gauge records), model calculations, and a discussion of the dominant reaction mechanisms in light of comparisons between experiment and model will be presented.
The Esri 3D city information model
NASA Astrophysics Data System (ADS)
Reitz, T.; Schubiger-Banz, S.
2014-02-01
With residential and commercial space becoming increasingly scarce, cities are going vertical. Managing the urban environments in 3D is an increasingly important and complex undertaking. To help solving this problem, Esri has released the ArcGIS for 3D Cities solution. The ArcGIS for 3D Cities solution provides the information model, tools and apps for creating, analyzing and maintaining a 3D city using the ArcGIS platform. This paper presents an overview of the 3D City Information Model and some sample use cases.
Cheng, Gang; Markenscoff, Pauline; Zygourakis, Kyriacos
2009-01-01
Abstract To provide theoretical guidance for the design and in vitro cultivation of bioartificial tissues, we have developed a multiscale computational model that can describe the complex interplay between cell population and mass transport dynamics that governs the growth of tissues in three-dimensional scaffolds. The model has three components: a transient partial differential equation for the simultaneous diffusion and consumption of a limiting nutrient; a cellular automaton describing cell migration, proliferation, and collision; and equations that quantify how the varying nutrient concentration modulates cell division and migration. The hybrid discrete-continuous model was parallelized and solved on a distributed-memory multicomputer to study how transport limitations affect tissue regeneration rates under conditions encountered in typical bioreactors. Simulation results show that the severity of transport limitations can be estimated by the magnitude of two dimensionless groups: the Thiele modulus and the Biot number. Key parameters including the initial seeding mode, cell migration speed, and the hydrodynamic conditions in the bioreactor are shown to affect not only the overall rate, but also the pattern of tissue growth. This study lays the groundwork for more comprehensive models that can handle mixed cell cultures, multiple nutrients and growth factors, and other cellular processes, such as cell death. PMID:19619455
BEAMS3D Neutral Beam Injection Model
Lazerson, Samuel
2014-04-14
With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.
NASA Astrophysics Data System (ADS)
Zurek, A. J.; Witczak, S.; Dulinski, M.; Wachniew, P.; Rozanski, K.; Kania, J.; Postawa, A.; Karczewski, J.; Moscicki, W. J.
2014-08-01
A dedicated study was launched in 2010 with the main aim to better understand the functioning of groundwater dependent terrestrial ecosystem (GDTE) located in southern Poland. The GDTE consists of a valuable forest stand (Niepolomice Forest) and associated wetland (Wielkie Bloto fen). A wide range of tools (environmental tracers, geochemistry, geophysics, 3-D flow and transport modeling) was used. The research was conducted along three major directions: (i) quantification of the dynamics of groundwater flow in various parts of the aquifer associated with GDTE, (ii) quantification of the degree of interaction between the GDTE and the aquifer, and (iii) 3-D modeling of groundwater flow in the vicinity of the studied GDTE and quantification of possible impact of enhanced exploitation of the aquifer on the status of GDTE. Environmental tracer data (tritium, stable isotopes of water) strongly suggest that upward leakage of the aquifer contributes significantly to the present water balance of the studied wetland and associated forest. Physico-chemical parameters of water (pH, conductivity, Na / Cl ratio) confirm this notion. Model runs indicate that prolonged groundwater abstraction through the newly-established network of water supply wells, conducted at maximum permitted capacity (ca. 10 000 m3 d-1), may trigger drastic changes in the ecosystem functioning, eventually leading to its degradation.
NASA Technical Reports Server (NTRS)
Fung, Inez Y.; Tucker, C. J.; Prentice, Katharine C.
1985-01-01
The 'normalized difference vegetation indices' (NVI) derived from AVHRR radiances are combined with field data of soil respiration and a global map of net primary productivity to prescribe, for the globe, the seasonal exchange of CO2 between the atmosphere and the terrestrial biosphere. The monthly fluxes of CO2 thus obtained are used as inputs to a 3-D tracer transport model which uses winds generated by a 3-D atmospheric general circulation model to advect CO2 as an inert constituent. Analysis of the 3-D model results shows reasonable agreement between the simulated and observed annual cycles of atmospheric CO2 at the locations of the remote monitoring stations. The application is shown of atmospheric CO2 distributions to calibrate the NVI in terms of carbon fluxes. The approach suggests that the NVI may be used to provide quantitative information about long term and global scale variations of photosynthetic activity and of atmospheric CO2 concentrations provided that variations in the atmospheric circulation and in atmospheric composition are known.
Modeling Cellular Processes in 3-D
Mogilner, Alex; Odde, David
2011-01-01
Summary Recent advances in photonic imaging and fluorescent protein technology offer unprecedented views of molecular space-time dynamics in living cells. At the same time, advances in computing hardware and software enable modeling of ever more complex systems, from global climate to cell division. As modeling and experiment become more closely integrated, we must address the issue of modeling cellular processes in 3-D. Here, we highlight recent advances related to 3-D modeling in cell biology. While some processes require full 3-D analysis, we suggest that others are more naturally described in 2-D or 1-D. Keeping the dimensionality as low as possible reduces computational time and makes models more intuitively comprehensible; however, the ability to test full 3-D models will build greater confidence in models generally and remains an important emerging area of cell biological modeling. PMID:22036197
Voss, Clifford I.; Provost, A.M.
2002-01-01
SUTRA (Saturated-Unsaturated Transport) is a computer program that simulates fluid movement and the transport of either energy or dissolved substances in a subsurface environment. This upgraded version of SUTRA adds the capability for three-dimensional simulation to the former code (Voss, 1984), which allowed only two-dimensional simulation. The code employs a two- or three-dimensional finite-element and finite-difference method to approximate the governing equations that describe the two interdependent processes that are simulated: 1) fluid density-dependent saturated or unsaturated ground-water flow; and 2) either (a) transport of a solute in the ground water, in which the solute may be subject to: equilibrium adsorption on the porous matrix, and both first-order and zero-order production or decay; or (b) transport of thermal energy in the ground water and solid matrix of the aquifer. SUTRA may also be used to simulate simpler subsets of the above processes. A flow-direction-dependent dispersion process for anisotropic media is also provided by the code and is introduced in this report. As the primary calculated result, SUTRA provides fluid pressures and either solute concentrations or temperatures, as they vary with time, everywhere in the simulated subsurface system. SUTRA flow simulation may be employed for two-dimensional (2D) areal, cross sectional and three-dimensional (3D) modeling of saturated ground-water flow systems, and for cross sectional and 3D modeling of unsaturated zone flow. Solute-transport simulation using SUTRA may be employed to model natural or man-induced chemical-species transport including processes of solute sorption, production, and decay. For example, it may be applied to analyze ground-water contaminant transport problems and aquifer restoration designs. In addition, solute-transport simulation with SUTRA may be used for modeling of variable-density leachate movement, and for cross sectional modeling of saltwater intrusion in
3D model reconstruction of underground goaf
NASA Astrophysics Data System (ADS)
Fang, Yuanmin; Zuo, Xiaoqing; Jin, Baoxuan
2005-10-01
Constructing 3D model of underground goaf, we can control the process of mining better and arrange mining work reasonably. However, the shape of goaf and the laneway among goafs are very irregular, which produce great difficulties in data-acquiring and 3D model reconstruction. In this paper, we research on the method of data-acquiring and 3D model construction of underground goaf, building topological relation among goafs. The main contents are as follows: a) The paper proposed an efficient encoding rule employed to structure the field measurement data. b) A 3D model construction method of goaf is put forward, which by means of combining several TIN (triangulated irregular network) pieces, and an efficient automatic processing algorithm of boundary of TIN is proposed. c) Topological relation of goaf models is established. TIN object is the basic modeling element of goaf 3D model, and the topological relation among goaf is created and maintained by building the topological relation among TIN objects. Based on this, various 3D spatial analysis functions can be performed including transect and volume calculation of goaf. A prototype is developed, which can realized the model and algorithm proposed in this paper.
Merritt, Michael L.; Konikow, Leonard F.
2000-01-01
Heads and flow patterns in surficial aquifers can be strongly influenced by the presence of stationary surface-water bodies (lakes) that are in direct contact, vertically and laterally, with the aquifer. Conversely, lake stages can be significantly affected by the volume of water that seeps through the lakebed that separates the lake from the aquifer. For these reasons, a set of computer subroutines called the Lake Package (LAK3) was developed to represent lake/aquifer interaction in numerical simulations using the U.S. Geological Survey three-dimensional, finite-difference, modular ground-water flow model MODFLOW and the U.S. Geological Survey three-dimensional method-of-characteristics solute-transport model MOC3D. In the Lake Package described in this report, a lake is represented as a volume of space within the model grid which consists of inactive cells extending downward from the upper surface of the grid. Active model grid cells bordering this space, representing the adjacent aquifer, exchange water with the lake at a rate determined by the relative heads and by conductances that are based on grid cell dimensions, hydraulic conductivities of the aquifer material, and user-specified leakance distributions that represent the resistance to flow through the material of the lakebed. Parts of the lake may become ?dry? as upper layers of the model are dewatered, with a concomitant reduction in lake surface area, and may subsequently rewet when aquifer heads rise. An empirical approximation has been encoded to simulate the rewetting of a lake that becomes completely dry. The variations of lake stages are determined by independent water budgets computed for each lake in the model grid. This lake budget process makes the package a simulator of the response of lake stage to hydraulic stresses applied to the aquifer. Implementation of a lake water budget requires input of parameters including those representing the rate of lake atmospheric recharge and evaporation
Challenges in Lagrangian transport and predictability in 3D flows
NASA Astrophysics Data System (ADS)
Branicki, M.; Wiggins, S.; Kirwan, A. D.; Malek-Madani, R.
2011-12-01
The interplay between the geometrical theory of dynamical systems and the trajectory-based description of aperiodically time-dependent fluid flows has led to significant advances in understanding the role of chaotic transport in geophysical flows at scales dominated by advection. Lagrangian transport analysis utilizing either the time-dependent geometry of intersecting stable and unstable manifolds of the so-called Distinguished Hyperbolic Trajectories (DHT), or ridges of finite-time Lyapunov exponent fields (LCS), provide a much needed and complementary insight into ephemeral mechanisms responsible for the existence of `leaky' transport barriers and 'leaky' mesoscale eddies. However, to date most oceanic applications have been confined to 2D analysis of near surface regions in 'perfect' flows not accounting for model or measurement error, and with the tacit assumption of negligible vertical velocities. I will systematically address issues concerning the regimes of applicability of two-dimensional analysis in 3D aperiodically time-dependent flows, as well as outstanding challenges in fully 3D Lagrangian transport analysis. Even for perfect horizontal velocities, little is known about the vertical extent of stable/unstable manifolds associated with DHTs and/or other special structures relevant to stratified 3D flows. In particular, their sensitivity to errors in the vertical velocities and data assimilation methods has been little studied. Rigorous results regarding the above issues will be illustrated by revealing and mathematically tractable toy models, as well as examples from a detailed study in an eddy-rich region from the Gulf of Mexico and the Mediterranean. New ways of quantifying the uncertainty in Lagrangian predictions will also be presented.
NASA Astrophysics Data System (ADS)
Le Fouest, Vincent; Chami, Malik; Verney, Romaric
2015-02-01
The export of riverine suspended particulate matter (SPM) in the coastal ocean has major implications for the biogeochemical cycles. In the Mediterranean Sea (France), the Rhone River inputs of SPM into the Gulf of Lion (GoL) are highly variable in time, which severely impedes the assessment of SPM fluxes. The objectives of this study are (i) to investigate the prediction of the land-to-ocean flux of SPM using the complementarity (i.e., synergy) between a hydrodynamic sediment transport model and satellite observations, and (ii) to analyze the spatial distribution of the SPM export. An original approach that combines the MARS-3D model with satellite ocean color data is proposed. Satellite-derived SPM and light penetration depth are used to initialize MARS-3D and to validate its predictions. A sensitivity analysis is performed to quantify the impact of riverine SPM size composition and settling rate on the horizontal export of SPM. The best agreement between the model and the satellite in terms of SPM spatial distribution and export is obtained for two conditions: (i) when the relative proportion of "heavy and fast" settling particles significantly increases relative to the "light and slow" ones, and (ii) when the settling rate of heavy and light SPM increases by fivefold. The synergy between MARS-3D and the satellite data improved the SPM flux predictions by 48% near the Rhone River mouth. Our results corroborate the importance of implementing satellite observations within initialization procedures of ocean models since data assimilation techniques may fail for river floods showing strong seasonal variability.
New Algorithms for Large-scale 3D Radiation Transport
NASA Astrophysics Data System (ADS)
Lentz, Eric J.
2009-05-01
Radiation transport is critical not only for analysis of astrophysical objects but also for the dynamical transport of energy within. Increased fidelity and dimensionality of the other components of such models requires a similar improvement in the radiation transport. Modern astrophysical simulations can be large enough that the values for a single variable for the entire computational domain cannot be stored on a single compute node. The natural solution is to decompose the physical domain into pieces with each node responsible for a single sub-domain. Using localized plus "ghost" zone data works well for problems like explicit hydrodynamics or nuclear reaction networks with modest impact from inter-process communication. Unfortunately, radiation transport is an inherently non-local process that couples the entire model domain together and efficient algorithms are needed to conquer this problem. In this poster, I present the early development of a new parallel, 3-D transport code using ray tracing to formally solve the transport equation across numerically decomposed domains. The algorithm model takes advantage of one-sided communication to develop a scalable, parallel formal solver. Other aspects and future direction of the parallel code development such as scalability and the inclusion of scattering will also be discussed.
NASA Technical Reports Server (NTRS)
Ott, Lesley; Pickering, Kenneth; Stenchikov, Georgiy; Allen, Dale; DeCaria, Alex; Ridley, Brian; Lin, Ruei-Fong; Lang, Steve; Tao, Wei-Kuo
2009-01-01
A 3-D cloud scale chemical transport model that includes a parameterized source of lightning NO(x), based on observed flash rates has been used to simulate six midlatitude and subtropical thunderstorms observed during four field projects. Production per intracloud (P(sub IC) and cloud-to-ground (P(sub CG)) flash is estimated by assuming various values of P(sub IC) and P(sub CG) for each storm and determining which production scenario yields NO(x) mixing ratios that compare most favorably with in-cloud aircraft observations. We obtain a mean P(sub CG) value of 500 moles NO (7 kg N) per flash. The results of this analysis also suggest that on average, P(sub IC) may be nearly equal to P(sub CG), which is contrary to the common assumption that intracloud flashes are significantly less productive of NO than are cloud-to-ground flashes. This study also presents vertical profiles of the mass of lightning NO(x), after convection based on 3-D cloud-scale model simulations. The results suggest that following convection, a large percentage of lightning NO(x), remains in the middle and upper troposphere where it originated, while only a small percentage is found near the surface. The results of this work differ from profiles calculated from 2-D cloud-scale model simulations with a simpler lightning parameterization that were peaked near the surface and in the upper troposphere (referred to as a "C-shaped" profile). The new model results (a backward C-shaped profile) suggest that chemical transport models that assume a C-shaped vertical profile of lightning NO(x) mass may place too much mass neat the surface and too little in the middle troposphere.
Quantum transport through 3D Dirac materials
Salehi, M.; Jafari, S.A.
2015-08-15
Bismuth and its alloys provide a paradigm to realize three dimensional materials whose low-energy effective theory is given by Dirac equation in 3+1 dimensions. We study the quantum transport properties of three dimensional Dirac materials within the framework of Landauer–Büttiker formalism. Charge carriers in normal metal satisfying the Schrödinger equation, can be split into four-component with appropriate matching conditions at the boundary with the three dimensional Dirac material (3DDM). We calculate the conductance and the Fano factor of an interface separating 3DDM from a normal metal, as well as the conductance through a slab of 3DDM. Under certain circumstances the 3DDM appears transparent to electrons hitting the 3DDM. We find that electrons hitting the metal-3DDM interface from metallic side can enter 3DDM in a reversed spin state as soon as their angle of incidence deviates from the direction perpendicular to interface. However the presence of a second interface completely cancels this effect.
Quantum transport through 3D Dirac materials
NASA Astrophysics Data System (ADS)
Salehi, M.; Jafari, S. A.
2015-08-01
Bismuth and its alloys provide a paradigm to realize three dimensional materials whose low-energy effective theory is given by Dirac equation in 3+1 dimensions. We study the quantum transport properties of three dimensional Dirac materials within the framework of Landauer-Büttiker formalism. Charge carriers in normal metal satisfying the Schrödinger equation, can be split into four-component with appropriate matching conditions at the boundary with the three dimensional Dirac material (3DDM). We calculate the conductance and the Fano factor of an interface separating 3DDM from a normal metal, as well as the conductance through a slab of 3DDM. Under certain circumstances the 3DDM appears transparent to electrons hitting the 3DDM. We find that electrons hitting the metal-3DDM interface from metallic side can enter 3DDM in a reversed spin state as soon as their angle of incidence deviates from the direction perpendicular to interface. However the presence of a second interface completely cancels this effect.
NASA Astrophysics Data System (ADS)
Paradis, Hedvig; Andersson, Martin; Sundén, Bengt
2015-09-01
A 3D model at microscale by the lattice Boltzmann method (LBM) is proposed for part of an anode of a solid oxide fuel cell (SOFC) to analyze the interaction between the transport and reaction processes and structural parameters. The equations of charge, momentum, heat and mass transport are simulated in the model. The modeling geometry is created with randomly placed spheres to resemble the part of the anode structure close to the electrolyte. The electrochemical reaction processes are captured at specific sites where spheres representing Ni and YSZ materials are present with void space. This work focuses on analyzing the effect of structural parameters such as porosity, and percentage of active reaction sites on the ionic current density and concentration of H2 using LBM. It is shown that LBM can be used to simulate an SOFC anode at microscale and evaluate the effect of structural parameters on the transport processes to improve the performance of the SOFC anode. It was found that increasing the porosity from 30 to 50 % decreased the ionic current density due to a reduction in the number of reaction sites. Also the consumption of H2 decreased with increasing porosity. When the percentage of active reaction sites was increased while the porosity was kept constant, the ionic current density increased. However, the H2 concentration was slightly reduced when the percentage of active reaction sites was increased. The gas flow tortuosity decreased with increasing porosity.
NASA Astrophysics Data System (ADS)
Paradis, Hedvig; Andersson, Martin; Sundén, Bengt
2016-08-01
A 3D model at microscale by the lattice Boltzmann method (LBM) is proposed for part of an anode of a solid oxide fuel cell (SOFC) to analyze the interaction between the transport and reaction processes and structural parameters. The equations of charge, momentum, heat and mass transport are simulated in the model. The modeling geometry is created with randomly placed spheres to resemble the part of the anode structure close to the electrolyte. The electrochemical reaction processes are captured at specific sites where spheres representing Ni and YSZ materials are present with void space. This work focuses on analyzing the effect of structural parameters such as porosity, and percentage of active reaction sites on the ionic current density and concentration of H2 using LBM. It is shown that LBM can be used to simulate an SOFC anode at microscale and evaluate the effect of structural parameters on the transport processes to improve the performance of the SOFC anode. It was found that increasing the porosity from 30 to 50 % decreased the ionic current density due to a reduction in the number of reaction sites. Also the consumption of H2 decreased with increasing porosity. When the percentage of active reaction sites was increased while the porosity was kept constant, the ionic current density increased. However, the H2 concentration was slightly reduced when the percentage of active reaction sites was increased. The gas flow tortuosity decreased with increasing porosity.
3D Modeling Engine Representation Summary Report
Steven Prescott; Ramprasad Sampath; Curtis Smith; Timothy Yang
2014-09-01
Computers have been used for 3D modeling and simulation, but only recently have computational resources been able to give realistic results in a reasonable time frame for large complex models. This summary report addressed the methods, techniques, and resources used to develop a 3D modeling engine to represent risk analysis simulation for advanced small modular reactor structures and components. The simulations done for this evaluation were focused on external events, specifically tsunami floods, for a hypothetical nuclear power facility on a coastline.
Ishihara, T.; Kim, J.K.; Kobayashi, Y.
1995-10-01
In this study, martensite-ferrite dual phase steel composed of martensite in hard phase and ferrite in soft phase is made 3 dimensions fabric composite for energy transport and the difference in fatigue crack propagation behavior resulting from the structural size is investigated by fracture mechanics and microstructural method. The main results obtained are as follows: (1) the fatigue crack propagation rate is influenced by the ferrite grain size, in other words, in the low {Delta}K region the fatigue crack propagation rate is decreased with decreasing of the grain size but the difference of propagation rate resulted from the structural size is decreased as {Delta}K is increased; (2) the above results are explained by the degree of crack arrest effect of the martensite phase for the fatigue crack propagation depending on the ratio of reversed plastic zone size to the ferrite grain size.
NASA Astrophysics Data System (ADS)
Zurek, A. J.; Witczak, S.; Dulinski, M.; Wachniew, P.; Rozanski, K.; Kania, J.; Postawa, A.; Karczewski, J.; Moscicki, W. J.
2015-02-01
Groundwater-dependent ecosystems (GDEs) have important functions in all climatic zones as they contribute to biological and landscape diversity and provide important economic and social services. Steadily growing anthropogenic pressure on groundwater resources creates a conflict situation between nature and man which are competing for clean and safe sources of water. Such conflicts are particularly noticeable in GDEs located in densely populated regions. A dedicated study was launched in 2010 with the main aim to better understand the functioning of a groundwater-dependent terrestrial ecosystem (GDTE) located in southern Poland. The GDTE consists of a valuable forest stand (Niepolomice Forest) and associated wetland (Wielkie Błoto fen). It relies mostly on groundwater from the shallow Quaternary aquifer and possibly from the deeper Neogene (Bogucice Sands) aquifer. In July 2009 a cluster of new pumping wells abstracting water from the Neogene aquifer was set up 1 km to the northern border of the fen. A conceptual model of the Wielkie Błoto fen area for the natural, pre-exploitation state and for the envisaged future status resulting from intense abstraction of groundwater through the new well field was developed. The main aim of the reported study was to probe the validity of the conceptual model and to quantify the expected anthropogenic impact on the studied GDTE. A wide range of research tools was used. The results obtained through combined geologic, geophysical, geochemical, hydrometric and isotope investigations provide strong evidence for the existence of upward seepage of groundwater from the deeper Neogene aquifer to the shallow Quaternary aquifer supporting the studied GDTE. Simulations of the groundwater flow field in the study area with the aid of a 3-D flow and transport model developed for Bogucice Sands (Neogene) aquifer and calibrated using environmental tracer data and observations of hydraulic head in three different locations on the study area
BEAMS3D Neutral Beam Injection Model
NASA Astrophysics Data System (ADS)
McMillan, Matthew; Lazerson, Samuel A.
2014-09-01
With the advent of applied 3D fields in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous slowing down, and pitch angle scattering are modeled with the ADAS atomic physics database. Elementary benchmark calculations are presented to verify the collisionless particle orbits, NBI model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields. Notice: this manuscript has been authored by Princeton University under Contract Number DE-AC02-09CH11466 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.
Solar abundances and 3D model atmospheres
NASA Astrophysics Data System (ADS)
Ludwig, Hans-Günter; Caffau, Elisabetta; Steffen, Matthias; Bonifacio, Piercarlo; Freytag, Bernd; Cayrel, Roger
2010-03-01
We present solar photospheric abundances for 12 elements from optical and near-infrared spectroscopy. The abundance analysis was conducted employing 3D hydrodynamical (CO5BOLD) as well as standard 1D hydrostatic model atmospheres. We compare our results to others with emphasis on discrepancies and still lingering problems, in particular exemplified by the pivotal abundance of oxygen. We argue that the thermal structure of the lower solar photosphere is very well represented by our 3D model. We obtain an excellent match of the observed center-to-limb variation of the line-blanketed continuum intensity, also at wavelengths shortward of the Balmer jump.
ERIC Educational Resources Information Center
Bradley, Joan; Farland-Smith, Donna
2010-01-01
Allowing a student to "see" through touch what other students see through a microscope can be a challenging task. Therefore, author Joan Bradley created three-dimensional (3-D) models with one student's visual impairment in mind. They are meant to benefit all students and can be used to teach common high school biology topics, including the…
Virtual 3d City Modeling: Techniques and Applications
NASA Astrophysics Data System (ADS)
Singh, S. P.; Jain, K.; Mandla, V. R.
2013-08-01
-D City model is a very useful for various kinds of applications such as for planning in Navigation, Tourism, Disasters Management, Transportations, Municipality, Urban Environmental Managements and Real-estate industry. So the Construction of Virtual 3-D city models is a most interesting research topic in recent years.
Debris Dispersion Model Using Java 3D
NASA Technical Reports Server (NTRS)
Thirumalainambi, Rajkumar; Bardina, Jorge
2004-01-01
This paper describes web based simulation of Shuttle launch operations and debris dispersion. Java 3D graphics provides geometric and visual content with suitable mathematical model and behaviors of Shuttle launch. Because the model is so heterogeneous and interrelated with various factors, 3D graphics combined with physical models provides mechanisms to understand the complexity of launch and range operations. The main focus in the modeling and simulation covers orbital dynamics and range safety. Range safety areas include destruct limit lines, telemetry and tracking and population risk near range. If there is an explosion of Shuttle during launch, debris dispersion is explained. The shuttle launch and range operations in this paper are discussed based on the operations from Kennedy Space Center, Florida, USA.
Diffusion approximation for modeling of 3-D radiation distributions
Zardecki, A.; Gerstl, S.A.W.; De Kinder, R.E. Jr.
1985-01-01
A three-dimensional transport code DIF3D, based on the diffusion approximation, is used to model the spatial distribution of radiation energy arising from volumetric isotropic sources. Future work will be concerned with the determination of irradiances and modeling of realistic scenarios, relevant to the battlefield conditions. 8 refs., 4 figs.
3-D numerical simulations of volcanic ash transport and deposition
NASA Astrophysics Data System (ADS)
Suzuki, Y. J.; Koyaguchi, T.
2012-12-01
During an explosive volcanic eruption, volcanic gas and pyroclasts are ejected from the volcanic vent. The pyroclasts are carried up within a convective plume, advected by the surrounding wind field, and sediment on the ground depending on their terminal velocity. The fine ash are expected to have atmospheric residence, whereas the coarser particles form fall deposits. Accurate modeling of particle transport and deposition is of critical importance from the viewpoint of disaster prevention. Previously, some particle-tracking models (e.g., PUFF) and advection-diffusion models (e.g., TEPHRA2 and FALL3D) tried to forecast particle concentration in the atmosphere and particle loading at ground level. However, these models assumed source conditions (the grain-size distribution, plume height, and mass release location) based on the simple 1-D model of convective plume. In this study, we aim to develop a new 3-D model which reproduces both of the dynamics of convective plume and the ash transport. The model is designed to describe the injection of eruption cloud and marker particles from a circular vent above a flat surface into the stratified atmosphere. Because the advection is the predominant mechanism of particle transport near the volcano, the diffusive process is not taken into account in this model. The distribution of wind velocity is given as an initial condition. The model of the eruption cloud dynamics is based on the 3-D time-dependent model of Suzuki et al. (2005). We apply a pseudo-gas model to calculate the eruption cloud dynamics: the effect of particle separation on the cloud dynamics is not considered. In order to reproduce the drastic change of eruption cloud density, we change the effective gas constant and heat capacity of the mixture in the equation of state for ideal gases with the mixing ratio between the ejected material and entrained air. In order to calculate the location and movement of ash particles, the present model employs Lagrangian marker
Hoyer, Andrea B; Wittmann, Marion E; Chandra, Sudeep; Schladow, S Geoffrey; Rueda, Francisco J
2014-12-01
The unwanted impacts of non-indigenous species have become one of the major ecological and economic threats to aquatic ecosystems worldwide. Assessing the potential dispersal and colonization of non-indigenous species is necessary to prevent or reduce deleterious effects that may lead to ecosystem degradation and a range of economic impacts. A three dimensional (3D) numerical model has been developed to evaluate the local dispersal of the planktonic larvae of an invasive bivalve, Asian clam (Corbicula fluminea), by passive hydraulic transport in Lake Tahoe, USA. The probability of dispersal of Asian clam larvae from the existing high density populations to novel habitats is determined by the magnitude and timing of strong wind events. The probability of colonization of new near-shore areas outside the existing beds is low, but sensitive to the larvae settling velocity ws. High larvae mortality was observed due to settling in unsuitable deep habitats. The impact of UV-radiation during the pelagic stages, on the Asian clam mortality was low. This work provides a quantification of the number of propagules that may be successfully transported as a result of natural processes and in function of population size. The knowledge and understanding of the relative contribution of different dispersal pathways, may directly inform decision-making and resource allocation associated with invasive species management. PMID:25108183
Illustrative visualization of 3D city models
NASA Astrophysics Data System (ADS)
Doellner, Juergen; Buchholz, Henrik; Nienhaus, Marc; Kirsch, Florian
2005-03-01
This paper presents an illustrative visualization technique that provides expressive representations of large-scale 3D city models, inspired by the tradition of artistic and cartographic visualizations typically found in bird"s-eye view and panoramic maps. We define a collection of city model components and a real-time multi-pass rendering algorithm that achieves comprehensible, abstract 3D city model depictions based on edge enhancement, color-based and shadow-based depth cues, and procedural facade texturing. Illustrative visualization provides an effective visual interface to urban spatial information and associated thematic information complementing visual interfaces based on the Virtual Reality paradigm, offering a huge potential for graphics design. Primary application areas include city and landscape planning, cartoon worlds in computer games, and tourist information systems.
Integrated Biogeomorphological Modeling Using Delft3D
NASA Astrophysics Data System (ADS)
Ye, Q.; Jagers, B.
2011-12-01
The skill of numerical morphological models has improved significantly from the early 2D uniform, total load sediment models (with steady state or infrequent wave updates) to recent 3D hydrodynamic models with multiple suspended and bed load sediment fractions and bed stratigraphy (online coupled with waves). Although there remain many open questions within this combined field of hydro- and morphodynamics, we observe an increasing need to include biological processes in the overall dynamics. In riverine and inter-tidal environments, there is often an important influence by riparian vegetation and macrobenthos. Over the past decade more and more researchers have started to extend the simulation environment with wrapper scripts and other quick code hacks to estimate their influence on morphological development in coastal, estuarine and riverine environments. Although one can in this way quickly analyze different approaches, these research tools have generally not been designed with reuse, performance and portability in mind. We have now implemented a reusable, flexible, and efficient two-way link between the Delft3D open source framework for hydrodynamics, waves and morphology, and the water quality and ecology modules. The same link will be used for 1D, 2D and 3D modeling on networks and both structured and unstructured grids. We will describe the concepts of the overall system, and illustrate it with some first results.
Sensing and compressing 3-D models
Krumm, J.
1998-02-01
The goal of this research project was to create a passive and robust computer vision system for producing 3-D computer models of arbitrary scenes. Although the authors were unsuccessful in achieving the overall goal, several components of this research have shown significant potential. Of particular interest is the application of parametric eigenspace methods for planar pose measurement of partially occluded objects in gray-level images. The techniques presented provide a simple, accurate, and robust solution to the planar pose measurement problem. In addition, the representational efficiency of eigenspace methods used with gray-level features were successfully extended to binary features, which are less sensitive to illumination changes. The results of this research are presented in two papers that were written during the course of this project. The papers are included in sections 2 and 3. The first section of this report summarizes the 3-D modeling efforts.
3D modeling of optically challenging objects.
Park, Johnny; Kak, Avinash
2008-01-01
We present a system for constructing 3D models of real-world objects with optically challenging surfaces. The system utilizes a new range imaging concept called multi-peak range imaging, which stores multiple candidates of range measurements for each point on the object surface. The multiple measurements include the erroneous range data caused by various surface properties that are not ideal for structured-light range sensing. False measurements generated by spurious reflections are eliminated by applying a series of constraint tests. The constraint tests based on local surface and local sensor visibility are applied first to individual range images. The constraint tests based on global consistency of coordinates and visibility are then applied to all range images acquired from different viewpoints. We show the effectiveness of our method by constructing 3D models of five different optically challenging objects. To evaluate the performance of the constraint tests and to examine the effects of the parameters used in the constraint tests, we acquired the ground truth data by painting those objects to suppress the surface-related properties that cause difficulties in range sensing. Experimental results indicate that our method significantly improves upon the traditional methods for constructing reliable 3D models of optically challenging objects. PMID:18192707
NASA Astrophysics Data System (ADS)
Berchtold, Waldemar; Schäfer, Marcel; Rettig, Michael; Steinebach, Martin
2014-02-01
3D models and applications are of utmost interest in both science and industry. With the increment of their usage, their number and thereby the challenge to correctly identify them increases. Content identification is commonly done by cryptographic hashes. However, they fail as a solution in application scenarios such as computer aided design (CAD), scientific visualization or video games, because even the smallest alteration of the 3D model, e.g. conversion or compression operations, massively changes the cryptographic hash as well. Therefore, this work presents a robust hashing algorithm for 3D mesh data. The algorithm applies several different bit extraction methods. They are built to resist desired alterations of the model as well as malicious attacks intending to prevent correct allocation. The different bit extraction methods are tested against each other and, as far as possible, the hashing algorithm is compared to the state of the art. The parameters tested are robustness, security and runtime performance as well as False Acceptance Rate (FAR) and False Rejection Rate (FRR), also the probability calculation of hash collision is included. The introduced hashing algorithm is kept adaptive e.g. in hash length, to serve as a proper tool for all applications in practice.
Fallon FORGE 3D Geologic Model
Doug Blankenship
2016-03-01
An x,y,z scattered data file for the 3D geologic model of the Fallon FORGE site. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.
3D Models of Symbiotic Binaries
NASA Astrophysics Data System (ADS)
Mohamed, S.; Booth, R.; Podsiadlowski, Ph.; Ramstedt, S.; Vlemmings, W.; Maercker, M.
2015-12-01
Symbiotic binaries consist of a cool, mass-losing giant and an accreting, compact companion. We present 3D Smoothed Particle Hydrodynamics (SPH) models of two such interacting binaries, RS Oph and Mira AB. RS Oph is also a recurrent nova system, thus we model multiple quiescent mass transfer-nova outburst cycles. The resulting circumstellar structures of both systems are highly complex with the formation of spirals, arcs, shells, equatorial and bipolar outflows. We compare the models to recent observations and discuss the implications of our results for related systems, e.g., bipolar nebulae and jets, chemically peculiar stars, and the progenitors of Type Ia supernovae.
Inferential modeling of 3D chromatin structure
Wang, Siyu; Xu, Jinbo; Zeng, Jianyang
2015-01-01
For eukaryotic cells, the biological processes involving regulatory DNA elements play an important role in cell cycle. Understanding 3D spatial arrangements of chromosomes and revealing long-range chromatin interactions are critical to decipher these biological processes. In recent years, chromosome conformation capture (3C) related techniques have been developed to measure the interaction frequencies between long-range genome loci, which have provided a great opportunity to decode the 3D organization of the genome. In this paper, we develop a new Bayesian framework to derive the 3D architecture of a chromosome from 3C-based data. By modeling each chromosome as a polymer chain, we define the conformational energy based on our current knowledge on polymer physics and use it as prior information in the Bayesian framework. We also propose an expectation-maximization (EM) based algorithm to estimate the unknown parameters of the Bayesian model and infer an ensemble of chromatin structures based on interaction frequency data. We have validated our Bayesian inference approach through cross-validation and verified the computed chromatin conformations using the geometric constraints derived from fluorescence in situ hybridization (FISH) experiments. We have further confirmed the inferred chromatin structures using the known genetic interactions derived from other studies in the literature. Our test results have indicated that our Bayesian framework can compute an accurate ensemble of 3D chromatin conformations that best interpret the distance constraints derived from 3C-based data and also agree with other sources of geometric constraints derived from experimental evidence in the previous studies. The source code of our approach can be found in https://github.com/wangsy11/InfMod3DGen. PMID:25690896
NASA Astrophysics Data System (ADS)
Zhang, Y.; Jacob, D. J.; Dutkiewicz, S.; Amos, H. M.; Long, M. S.; Sunderland, E. M.
2014-12-01
Rivers are estimated to deliver 27 Mmol a-1 of mercury (Hg) to ocean margins, which is comparable to the global atmospheric deposition flux of Hg to the ocean. Previous studies presumed that most of this riverine Hg is sequestered by settling to the coastal regions. However, there has been little investigation of the mechanism and efficiency with which this sequestration takes place, and the implications for riverine influence in different ocean regions. Here we develop a global 3-D chemical transport model for Hg in the ocean (MITgcm-Hg) with ecology (DARWIN model). We track offshore export of the discharged Hg from heterogeneous river systems over different ocean regions, and how it is influenced by the interaction of Hg in a variety of geochemical forms with carbon and suspended particles. We constrain our model assumptions with available offshore observations that bear strong riverine signals. Modeling results suggest that some of the riverine Hg is highly refractory, sorbs strongly to particles and does not follow equilibrium partitioning with the dissolved phase. Simulated global Hg evasion from riverine sources is 50 times larger without this refractory particulate pool, which results in a total evasion flux two times larger than our current best estimate. Based on a typology system of global rivers, we calculate that 10% to 60% of the particulate Hg from different rivers settles in ocean margin sediments because of subgrid sedimentation processes. The remaining 7.5 Mmol a-1 (28% of total river discharge) is available for offshore transport, where it undergoes further sedimentation to the shelf (5.3 Mmol a-1) as well as evasion to the atmosphere (0.44 Mmol a-1). Only 1.7 Mmol a-1 (6.4% of the global riverine Hg) reaches the open ocean, although that fraction varies from 2.6% in East Asia because of the blockage of Korean Peninsula to 25% in east North America facilitated by the Gulf Stream. We find large riverine influences over coastal oceans off East Asia
3D Babcock-Leighton Solar Dynamo Models
NASA Astrophysics Data System (ADS)
Miesch, Mark S.; Hazra, Gopal; Karak, Bidya Binay; Teweldebirhan, Kinfe; Upton, Lisa
2016-05-01
We present results from the new STABLE (Surface flux Transport and Babcock Leighton) Dynamo Model. STABLE is a 3D Babcock-Leighton/Flux Transport dynamo model in which the source of poloidal field is the explicit emergence, distortion, and dispersal of bipolar magnetic regions (BMRs). In this talk I will discuss initial results with axisymmetric flow fields, focusing on the operation of the model, the general features of the cyclic solutions, and the challenge of achieving supercritical dynamo solutions using only the Babcock-Leighton source term. Then I will present dynamo simulations that include 3D convective flow fields based on the observed velocity power spectrum inferred from photospheric Dopplergrams. I'll use these simulations to assess how the explicit transport and amplification of fields by surface convection influences the operation of the dynamo. I will also discuss the role of surface magnetic fields in regulating the subsurface toroidal flux budget.
3D Model of Surfactant Replacement Therapy
NASA Astrophysics Data System (ADS)
Grotberg, James; Tai, Cheng-Feng; Filoche, Marcel
2015-11-01
Surfactant Replacement Therapy (SRT) involves instillation of a liquid-surfactant mixture directly into the lung airway tree. Though successful in neonatal applications, its use in adults had early success followed by failure. We present the first mathematical model of 3D SRT where a liquid plug propagates through the tree from forced inspiration. In two separate modeling steps, the plug first deposits a coating film on the airway wall which subtracts from its volume, a ``coating cost''. Then the plug splits unevenly at the airway bifurcation due to gravity. The steps are repeated until a plug ruptures or reaches the tree endpoint alveoli/acinus. The model generates 3D images of the resulting acinar distribution and calculates two global indexes, efficiency and homogeneity. Simulating published literature, the earlier successful adult SRT studies show comparatively good index values, while the later failed studies do not. Those unsuccessful studies used smaller dose volumes with higher concentration mixtures, apparently assuming a well mixed compartment. The model shows that adult lungs are not well mixed in SRT due to the coating cost and gravity effects. Returning to the higher dose volume protocols could save many thousands of lives annually in the US. Supported by NIH Grants HL85156, HL84370 and Agence Nationale de la Recherche, ANR no. 2010-BLAN-1119-05.
NASA Astrophysics Data System (ADS)
Utembe, S. R.; Cooke, M. C.; Archibald, A. T.; Shallcross, D. E.; Derwent, R. G.; Jenkin, M. E.
2011-03-01
A secondary organic aerosol (SOA) code, coupled to the reduced Common Representative Intermediates chemical mechanism (CRI v2-R5), has been used in the global 3-D chemistry-transport model, STOCHEM, to simulate the global distribution of organic aerosol (OA) mass loadings. The SOA code represents the gas-to-aerosol partitioning of products formed over several generations of oxidation of a variety of organic precursors emitted from anthropogenic, biogenic and biomass burning sources. The model also includes emissions of primary organic aerosol (POA), based on the AeroCom inventory and the Global Fire Emissions database (GFED). The calculated burdens for POA, 0.89 Tg, and SOA, 0.23 Tg, are well within the range of values that have been reported in previous modelling studies. The calculated SOA annual in-situ production of 22.5 Tg yr -1 also falls within the 8-110 Tg yr -1 range calculated by other models, but is somewhat lower than observationally-constrained top-down estimates which have been reported recently. The oxidation of biogenic precursors is found to account for about 90% of the global SOA burden, and this makes a substantial contribution to the highest annual mean surface OA concentrations (up to 8 μg m -3), which are simulated in tropical forested regions. Comparison of the simulated OA mass loadings with surface observations from a variety of locations indicate a good description of the OA distribution, but with an average underestimation of about a factor of 3. Sustained formation of SOA into the free troposphere is simulated, with important contributions from second and third-generation products of terpene oxidation in the upper troposphere. Comparison of the simulated OA mass loadings with vertical profiles from the ACE-Asia campaign indicates a very good description of the relative variation of OA with altitude, but with consistent underestimation of about a factor of 5. Although the absolute magnitude of the global source strength is underestimated
MOSSFRAC: An anisotropic 3D fracture model
Moss, W C; Levatin, J L
2006-08-14
Despite the intense effort for nearly half a century to construct detailed numerical models of plastic flow and plastic damage accumulation, models for describing fracture, an equally important damage mechanism still cannot describe basic fracture phenomena. Typical fracture models set the stress tensor to zero for tensile fracture and set the deviatoric stress tensor to zero for compressive fracture. One consequence is that the simple case of the tensile fracture of a cylinder under combined compressive radial and tensile axial loads is not modeled correctly. The experimental result is a cylinder that can support compressive radial loads, but no axial load, whereas, the typical numerical result is a cylinder with all stresses equal to zero. This incorrect modeling of fracture locally also has a global effect, because material that is fracturing produces stress release waves, which propagate from the fracture and influence the surrounding material. Consequently, it would be useful to have a model that can describe the stress relief and the resulting anisotropy due to fracture. MOSSFRAC is a material model that simulates three-dimensional tensile and shear fracture in initially isotropic elastic-plastic materials, although its framework is also amenable to initially anisotropic materials. It differs from other models by accounting for the effects of cracks on the constitutive response of the material, so that the previously described experiment, as well as complicated fracture scenarios are simulated more accurately. The model is implemented currently in the LLNL hydrocodes DYNA3D, PARADYN, and ALE3D. The purpose of this technical note is to present a complete qualitative description of the model and quantitative descriptions of salient features.
3-D UNSTRUCTURED HEXAHEDRAL-MESH Sn TRANSPORT METHODS
J. MOREL; J. MCGHEE; ET AL
2000-11-01
This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). We have developed a method for solving the neutral-particle transport equation on 3-D unstructured hexahedral meshes using a S{sub n} discretization in angle in conjunction with a discontinuous finite-element discretization in space and a multigroup discretization in energy. Previous methods for solving this equation in 3-D have been limited to rectangular meshes. The unstructured-mesh method that we have developed is far more efficient for solving problems with complex 3-D geometric features than rectangular-mesh methods. In spite of having to make several compromises in our spatial discretization technique and our iterative solution technique, our method has been found to be both accurate and efficient for a broad class of problems.
A non-conforming 3D spherical harmonic transport solver
Van Criekingen, S.
2006-07-01
A new 3D transport solver for the time-independent Boltzmann transport equation has been developed. This solver is based on the second-order even-parity form of the transport equation. The angular discretization is performed through the expansion of the angular neutron flux in spherical harmonics (PN method). The novelty of this solver is the use of non-conforming finite elements for the spatial discretization. Such elements lead to a discontinuous flux approximation. This interface continuity requirement relaxation property is shared with mixed-dual formulations such as the ones based on Raviart-Thomas finite elements. Encouraging numerical results are presented. (authors)
3D Stratigraphic Modeling of Central Aachen
NASA Astrophysics Data System (ADS)
Dong, M.; Neukum, C.; Azzam, R.; Hu, H.
2010-05-01
Since 1980s, advanced computer hardware and software technologies, as well as multidisciplinary research have provided possibilities to develop advanced three dimensional (3D) simulation software for geosciences application. Some countries, such as USA1) and Canada2) 3), have built up regional 3D geological models based on archival geological data. Such models have played huge roles in engineering geology2), hydrogeology2) 3), geothermal industry1) and so on. In cooperating with the Municipality of Aachen, the Department of Engineering Geology of RWTH Aachen University have built up a computer-based 3D stratigraphic model of 50 meter' depth for the center of Aachen, which is a 5 km by 7 km geologically complex area. The uncorrelated data from multi-resources, discontinuous nature and unconformable connection of the units are main challenges for geological modeling in this area. The reliability of 3D geological models largely depends on the quality and quantity of data. Existing 1D and 2D geological data were collected, including 1) approximately 6970 borehole data of different depth compiled in Microsoft Access database and MapInfo database; 2) a Digital Elevation Model (DEM); 3) geological cross sections; and 4) stratigraphic maps in 1m, 2m and 5m depth. Since acquired data are of variable origins, they were managed step by step. The main processes are described below: 1) Typing errors of borehole data were identified and the corrected data were exported to Variowin2.2 to distinguish duplicate points; 2) The surface elevation of borehole data was compared to the DEM, and differences larger than 3m were eliminated. Moreover, where elevation data missed, it was read from the DEM; 3) Considerable data were collected from municipal constructions, such as residential buildings, factories, and roads. Therefore, many boreholes are spatially clustered, and only one or two representative points were picked out in such areas; After above procedures, 5839 boreholes with -x
3D Modeling of Equatorial Plasma Bubbles
NASA Astrophysics Data System (ADS)
Huba, Joseph; Joyce, Glenn; Krall, Jonathan
2011-10-01
Post-sunset ionospheric irregularities in the equatorial F region were first observed by Booker and Wells (1938) using ionosondes. This phenomenon has become known as equatorial spread F (ESF). During ESF the equatorial ionosphere becomes unstable because of a Rayleigh-Taylor-like instability: large scale (10s km) electron density ``bubbles'' can develop and rise to high altitudes (1000 km or greater at times). Understanding and modeling ESF is important because of its impact on space weather: it causes radio wave scintillation that degrades communication and navigation systems. In fact, it is the focus of of the Air Force Communications/Navigation Outage Forecast Satellite (C/NOFS) mission. We will describe 3D simulation results from the NRL ionosphere models SAMI3 and SAMI3/ESF of this phenomenon. In particular, we will examine the causes of the day-to-day ariability of ESF which is an unresolved problem at this time. Post-sunset ionospheric irregularities in the equatorial F region were first observed by Booker and Wells (1938) using ionosondes. This phenomenon has become known as equatorial spread F (ESF). During ESF the equatorial ionosphere becomes unstable because of a Rayleigh-Taylor-like instability: large scale (10s km) electron density ``bubbles'' can develop and rise to high altitudes (1000 km or greater at times). Understanding and modeling ESF is important because of its impact on space weather: it causes radio wave scintillation that degrades communication and navigation systems. In fact, it is the focus of of the Air Force Communications/Navigation Outage Forecast Satellite (C/NOFS) mission. We will describe 3D simulation results from the NRL ionosphere models SAMI3 and SAMI3/ESF of this phenomenon. In particular, we will examine the causes of the day-to-day ariability of ESF which is an unresolved problem at this time. Research supported by ONR.
Reservoir geology using 3D modelling tools
Dubrule, O.; Samson, P.; Segonds, D.
1996-12-31
The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological {open_quotes}objects{close_quotes} with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.
Reservoir geology using 3D modelling tools
Dubrule, O. ); Samson, P. ); Segonds, D. )
1996-01-01
The last decade has seen tremendous developments in the area of quantitative geological modelling. These developments have a significant impact on the current practice of constructing reservoir models. A structural model can first be constructed on the basis of depth-converted structural interpretations produced on a seismic interpretation workstation. Surfaces and faults can be represented as geological objects, and interactively modified. Once the tectonic framework has been obtained, intermediate stratigraphic surfaces can be constructed between the main structural surfaces. Within each layer, reservoir attributes can be represented using various techniques. Examples show how the distribution of different facies (i.e. from fine to coarse grain) can be represented, or how various depositional units (for instance channels, crevasses and lobes in a turbidite setting) can be modelled as geological [open quotes]objects[close quotes] with complex geometries. Elf Aquitaine, in close co-operation with the GOCAD project in Nancy (France) is investigating how geological models can be made more realistic by developing interactive functionalities. Examples show that, contrary to standard deterministic or geostatistical modelling techniques (which tend to be difficult to control) the use of new 3D tools allows the geologist to interactively modify geological surfaces (including faults) or volumetric properties. Thus, the sensitivity of various economic parameters (oil in place, connected volumes, reserves) to major geological uncertainties can be evaluated. It is argued that future breakthroughs in geological modelling techniques are likely to happen in the development of interactive approaches rather than in the research of new mathematical algorithms.
3D Geological Model for "LUSI" - a Deep Geothermal System
NASA Astrophysics Data System (ADS)
Sohrabi, Reza; Jansen, Gunnar; Mazzini, Adriano; Galvan, Boris; Miller, Stephen A.
2016-04-01
Geothermal applications require the correct simulation of flow and heat transport processes in porous media, and many of these media, like deep volcanic hydrothermal systems, host a certain degree of fracturing. This work aims to understand the heat and fluid transport within a new-born sedimentary hosted geothermal system, termed Lusi, that began erupting in 2006 in East Java, Indonesia. Our goal is to develop conceptual and numerical models capable of simulating multiphase flow within large-scale fractured reservoirs such as the Lusi region, with fractures of arbitrary size, orientation and shape. Additionally, these models can also address a number of other applications, including Enhanced Geothermal Systems (EGS), CO2 sequestration (Carbon Capture and Storage CCS), and nuclear waste isolation. Fractured systems are ubiquitous, with a wide-range of lengths and scales, making difficult the development of a general model that can easily handle this complexity. We are developing a flexible continuum approach with an efficient, accurate numerical simulator based on an appropriate 3D geological model representing the structure of the deep geothermal reservoir. Using previous studies, borehole information and seismic data obtained in the framework of the Lusi Lab project (ERC grant n°308126), we present here the first 3D geological model of Lusi. This model is calculated using implicit 3D potential field or multi-potential fields, depending on the geological context and complexity. This method is based on geological pile containing the geological history of the area and relationship between geological bodies allowing automatic computation of intersections and volume reconstruction. Based on the 3D geological model, we developed a new mesh algorithm to create hexahedral octree meshes to transfer the structural geological information for 3D numerical simulations to quantify Thermal-Hydraulic-Mechanical-Chemical (THMC) physical processes.
3-D HYDRODYNAMIC MODELING IN A GEOSPATIAL FRAMEWORK
Bollinger, J; Alfred Garrett, A; Larry Koffman, L; David Hayes, D
2006-08-24
3-D hydrodynamic models are used by the Savannah River National Laboratory (SRNL) to simulate the transport of thermal and radionuclide discharges in coastal estuary systems. Development of such models requires accurate bathymetry, coastline, and boundary condition data in conjunction with the ability to rapidly discretize model domains and interpolate the required geospatial data onto the domain. To facilitate rapid and accurate hydrodynamic model development, SRNL has developed a pre- and post-processor application in a geospatial framework to automate the creation of models using existing data. This automated capability allows development of very detailed models to maximize exploitation of available surface water radionuclide sample data and thermal imagery.
Regional geothermal 3D modelling in Denmark
NASA Astrophysics Data System (ADS)
Poulsen, S. E.; Balling, N.; Bording, T. S.; Nielsen, S. B.
2012-04-01
In the pursuit of sustainable and low carbon emission energy sources, increased global attention has been given to the exploration and exploitation of geothermal resources within recent decades. In 2009 a national multi-disciplinary geothermal research project was established. As a significant part of this project, 3D temperature modelling is to be carried out, with special emphasis on temperatures of potential geothermal reservoirs in the Danish area. The Danish subsurface encompasses low enthalpy geothermal reservoirs of mainly Triassic and Jurassic age. Geothermal plants at Amager (Copenhagen) and Thisted (Northern Jutland) have the capacity of supplying the district heating network with up to 14 MW and 7 MW, respectively, by withdrawing warm pore water from the Gassum (Lower Jurassic/Upper Triassic) and Bunter (Lower Triassic) sandstone reservoirs, respectively. Explorative studies of the subsurface temperature regime typically are based on a combination of observations and modelling. In this study, the open-source groundwater modelling code MODFLOW is modified to simulate the subsurface temperature distribution in three dimensions by taking advantage of the mathematical similarity between saturated groundwater flow (Darcy flow) and heat conduction. A numerical model of the subsurface geology in Denmark is built and parameterized from lithological information derived from joint interpretation of seismic surveys and borehole information. Boundary conditions are constructed from knowledge about the heat flow from the Earth's interior and the shallow ground temperature. Matrix thermal conductivities have been estimated from analysis of high-resolution temperature logs measured in deep wells and porosity-depth relations are included using interpreted main lithologies. The model takes into account the dependency of temperature and pressure on thermal conductivity. Moreover, a transient model based correction of the paleoclimatic thermal disturbance caused by the
3-D PARTICLE TRANSPORT WITHIN THE HUMAN UPPER RESPIRATORY TRACT
In this study trajectories of inhaled particulate matter (PM) were simulated within a three-dimensional (3-D) computer model of the human upper respiratory tract (URT). The airways were described by computer-reconstructed images of a silicone rubber cast of the human head, throat...
3D Shape and Indirect Appearance by Structured Light Transport.
OToole, Matthew; Mather, John; Kutulakos, Kiriakos N
2016-07-01
We consider the problem of deliberately manipulating the direct and indirect light flowing through a time-varying, general scene in order to simplify its visual analysis. Our approach rests on a crucial link between stereo geometry and light transport: while direct light always obeys the epipolar geometry of a projector-camera pair, indirect light overwhelmingly does not. We show that it is possible to turn this observation into an imaging method that analyzes light transport in real time in the optical domain, prior to acquisition. This yields three key abilities that we demonstrate in an experimental camera prototype: (1) producing a live indirect-only video stream for any scene, regardless of geometric or photometric complexity; (2) capturing images that make existing structured-light shape recovery algorithms robust to indirect transport; and (3) turning them into one-shot methods for dynamic 3D shape capture. PMID:27295455
NASA Technical Reports Server (NTRS)
Bidwell, Colin S.; Pinella, David; Garrison, Peter
1999-01-01
Collection efficiency and ice accretion calculations were made for a commercial transport using the NASA Lewis LEWICE3D ice accretion code, the ICEGRID3D grid code and the CMARC panel code. All of the calculations were made on a Windows 95 based personal computer. The ice accretion calculations were made for the nose, wing, horizontal tail and vertical tail surfaces. Ice shapes typifying those of a 30 minute hold were generated. Collection efficiencies were also generated for the entire aircraft using the newly developed unstructured collection efficiency method. The calculations highlight the flexibility and cost effectiveness of the LEWICE3D, ICEGRID3D, CMARC combination.
3-D physical models of amitosis (cytokinesis).
Cheng, Kang; Zou, Changhua
2005-01-01
Based on Newton's laws, extended Coulomb's law and published biological data, we develop our 3-D physical models of natural and normal amitosis (cytokinesis), for prokaryotes (bacterial cells) in M phase. We propose following hypotheses: Chromosome rings exclusion: No normally and naturally replicated chromosome rings (RCR) can occupy the same prokaryote, a bacterial cell. The RCR produce spontaneous and strong electromagnetic fields (EMF), that can be alternated environmentally, in protoplasm and cortex. The EMF is approximately a repulsive quasi-static electric (slowly variant and mostly electric) field (EF). The EF forces between the RCR are strong enough, and orderly accumulate contractile proteins that divide the procaryotes in the cell cortex of division plane or directly split the cell compartment envelope longitudinally. The radial component of the EF forces could also make furrows or cleavages of procaryotes. The EF distribution controls the protoplasm partition and completes the amitosis (cytokinesis). After the cytokinesis, the spontaneous and strong EF disappear because the net charge accumulation becomes weak, in the protoplasm. The exclusion is because the two sets of informative objects (RCR) have identical DNA codes information and they are electro magnetically identical, therefore they repulse from each other. We also compare divisions among eukaryotes, prokaryotes, mitochondria and chloroplasts and propose our hypothesis: The principles of our models are applied to divisions of mitochondria and chloroplasts of eucaryotes too because these division mechanisms are closer than others in a view of physics. Though we develop our model using 1 division plane (i.e., 1 cell is divided into 2 cells) as an example, the principle of our model is applied to the cases with multiple division planes (i.e., 1 cell is divided into multiple cells) too. PMID:15533619
Turbulence and transport in a 3D magnetic boundary
NASA Astrophysics Data System (ADS)
Agostini, Matteo; Carraro, Lorella; Ciaccio, Giovanni; de Masi, Gianluca; Rea, Cristina; Scarin, Paolo; Spizzo, Gianluca; Spolaore, Monica; Vianello, Nicola
2014-10-01
In present fusion devices the interaction between 3D magnetic field, edge kinetic properties and turbulence is a crucial issue; not only in intrinsically 3D configurations such as the stellarators, but also in tokamaks, where magnetic perturbations are applied to control ELMs and plasma wall interaction. In the RFX-mod reversed field pinch the spontaneous development at high plasma current of a helical magnetic state displays strong analogies with the aforementioned configurations. At the edge the presence of a stochastic layer and magnetic islands with a well-defined helical symmetry leads to a helical pattern of flow, pressure gradients and turbulent fluctuations: larger fluctuations and shorter correlation lengths are observed near the X-point of the magnetic island, where also a flow slowing-down occurs. Aim of this work is to study the effect of edge turbulence on particle transport in a 3D magnetic boundary, characterizing the properties of the edge blobs along the helical deformation. The magnetic topology also modifies kinetic properties, with higher pressure gradients observed close to the O-point of the island. The measurement of the time evolution of pressure gradient and blob characteristics, can clarify the mutual relation between these two quantities.
3D Models of Stellar Interactions
NASA Astrophysics Data System (ADS)
Mohamed, S.; Podsiadlowski, Ph.; Booth, R.; Maercker, M.; Ramstedt, S.; Vlemmings, W.; Harries, T.; Mackey, J.; Langer, N.; Corradi, R.
2014-04-01
Symbiotic binaries consist of a cool, evolved mass-losing giant and an accreting compact companion. As symbiotic nebulae show similar morphologies to those in planetary nebulae (so much so that it is often difficult to distinguish between the two), they are ideal laboratories for understanding the role a binary companion plays in shaping the circumstellar envelopes in these evolved systems. We will present 3D Smoothed Particle Hydrodynamics (SPH) models of interacting binaries, e.g. R Aquarii and Mira, and discuss the formation of spiral outflows, arcs, shells and equatorial density enhancements.We will also discuss the implications of the former for planetary nebulae, e.g. the Egg Nebula and Cat's Eye, and the latter for the formation of bipolar geometries, e.g. M2-9. We also investigate accretion and angular momentum evolution in symbiotic binaries which may be important to understand the formation of jets and more episodic mass-loss features we see in circumstellar envelopes and the orbital characteristics of binary central stars of planetary nebulae.
Multi-view and 3D deformable part models.
Pepik, Bojan; Stark, Michael; Gehler, Peter; Schiele, Bernt
2015-11-01
As objects are inherently 3D, they have been modeled in 3D in the early days of computer vision. Due to the ambiguities arising from mapping 2D features to 3D models, 3D object representations have been neglected and 2D feature-based models are the predominant paradigm in object detection nowadays. While such models have achieved outstanding bounding box detection performance, they come with limited expressiveness, as they are clearly limited in their capability of reasoning about 3D shape or viewpoints. In this work, we bring the worlds of 3D and 2D object representations closer, by building an object detector which leverages the expressive power of 3D object representations while at the same time can be robustly matched to image evidence. To that end, we gradually extend the successful deformable part model [1] to include viewpoint information and part-level 3D geometry information, resulting in several different models with different level of expressiveness. We end up with a 3D object model, consisting of multiple object parts represented in 3D and a continuous appearance model. We experimentally verify that our models, while providing richer object hypotheses than the 2D object models, provide consistently better joint object localization and viewpoint estimation than the state-of-the-art multi-view and 3D object detectors on various benchmarks (KITTI [2] , 3D object classes [3] , Pascal3D+ [4] , Pascal VOC 2007 [5] , EPFL multi-view cars[6] ). PMID:26440264
Interchain coupling and 3D modeling of trans-polyacetylene
Bronold, F.; Saxena, A.; Bishop, A.R.
1992-01-01
In spite of the success of the SSH model for trans-polyacetylene in interpreting many experimental results (e.g. optical and magnetic properties) there remain some aspects of the real material which are outside the scope of the simple 1D model. Especially ordering phenomena of doped and undoped trans-polyacetylene as well as transport properties (e.g. electronic and thermal conductivity) are beyond a 1D description. There are many attempts to construct a transport theory for this novel class of materials using solitons or polaxons as the basic ingredients. But so far it is not yet clear whether these typical 1D excitations still exist in crystalline transpolyacetylene. Therefore, to clarify the role which intrinsic self-localized nonlinear excitations characteristic of 1D models play in the bulk (3D) material, we study the stability of a polaronic excitation against interchain coupling. As a preliminary step we consider first two coupled t-(CH){sub x}-chains where the {pi}-electrons are allowed to hop from one chain to the other. Then we introduce a 3D generalization of the SSH model and study a polaron in a 3D crystalline environment.
Interchain coupling and 3D modeling of trans-polyacetylene
Bronold, F.; Saxena, A.; Bishop, A.R.
1992-09-01
In spite of the success of the SSH model for trans-polyacetylene in interpreting many experimental results (e.g. optical and magnetic properties) there remain some aspects of the real material which are outside the scope of the simple 1D model. Especially ordering phenomena of doped and undoped trans-polyacetylene as well as transport properties (e.g. electronic and thermal conductivity) are beyond a 1D description. There are many attempts to construct a transport theory for this novel class of materials using solitons or polaxons as the basic ingredients. But so far it is not yet clear whether these typical 1D excitations still exist in crystalline transpolyacetylene. Therefore, to clarify the role which intrinsic self-localized nonlinear excitations characteristic of 1D models play in the bulk (3D) material, we study the stability of a polaronic excitation against interchain coupling. As a preliminary step we consider first two coupled t-(CH){sub x}-chains where the {pi}-electrons are allowed to hop from one chain to the other. Then we introduce a 3D generalization of the SSH model and study a polaron in a 3D crystalline environment.
3D-GNOME: an integrated web service for structural modeling of the 3D genome
Szalaj, Przemyslaw; Michalski, Paul J.; Wróblewski, Przemysław; Tang, Zhonghui; Kadlof, Michal; Mazzocco, Giovanni; Ruan, Yijun; Plewczynski, Dariusz
2016-01-01
Recent advances in high-throughput chromosome conformation capture (3C) technology, such as Hi-C and ChIA-PET, have demonstrated the importance of 3D genome organization in development, cell differentiation and transcriptional regulation. There is now a widespread need for computational tools to generate and analyze 3D structural models from 3C data. Here we introduce our 3D GeNOme Modeling Engine (3D-GNOME), a web service which generates 3D structures from 3C data and provides tools to visually inspect and annotate the resulting structures, in addition to a variety of statistical plots and heatmaps which characterize the selected genomic region. Users submit a bedpe (paired-end BED format) file containing the locations and strengths of long range contact points, and 3D-GNOME simulates the structure and provides a convenient user interface for further analysis. Alternatively, a user may generate structures using published ChIA-PET data for the GM12878 cell line by simply specifying a genomic region of interest. 3D-GNOME is freely available at http://3dgnome.cent.uw.edu.pl/. PMID:27185892
3D-GNOME: an integrated web service for structural modeling of the 3D genome.
Szalaj, Przemyslaw; Michalski, Paul J; Wróblewski, Przemysław; Tang, Zhonghui; Kadlof, Michal; Mazzocco, Giovanni; Ruan, Yijun; Plewczynski, Dariusz
2016-07-01
Recent advances in high-throughput chromosome conformation capture (3C) technology, such as Hi-C and ChIA-PET, have demonstrated the importance of 3D genome organization in development, cell differentiation and transcriptional regulation. There is now a widespread need for computational tools to generate and analyze 3D structural models from 3C data. Here we introduce our 3D GeNOme Modeling Engine (3D-GNOME), a web service which generates 3D structures from 3C data and provides tools to visually inspect and annotate the resulting structures, in addition to a variety of statistical plots and heatmaps which characterize the selected genomic region. Users submit a bedpe (paired-end BED format) file containing the locations and strengths of long range contact points, and 3D-GNOME simulates the structure and provides a convenient user interface for further analysis. Alternatively, a user may generate structures using published ChIA-PET data for the GM12878 cell line by simply specifying a genomic region of interest. 3D-GNOME is freely available at http://3dgnome.cent.uw.edu.pl/. PMID:27185892
Predicting longshore gradients in longshore transport: the CERC formula compared to Delft3D
List, Jeffrey H.; Hanes, Daniel M.; Ruggiero, Peter
2007-01-01
The prediction of longshore transport gradients is critical for forecasting shoreline change. We employ simple test cases consisting of shoreface pits at varying distances from the shoreline to compare the longshore transport gradients predicted by the CERC formula against results derived from the process-based model Delft3D. Results show that while in some cases the two approaches give very similar results, in many cases the results diverge greatly. Although neither approach is validated with field data here, the Delft3D-based transport gradients provide much more consistent predictions of erosional and accretionary zones as the pit location varies across the shoreface.
NASA Astrophysics Data System (ADS)
Bergeon, N.; Mota, F. L.; Chen, L.; Tourret, D.; Debierre, J. M.; Guérin, R.; Karma, A.; Billia, B.; Trivedi, R.
2015-06-01
To clarify and characterize the fundamental physical mechanisms active in the dynamical formation of three-dimensional (3D) arrays of cells and dendrites under diffusive growth conditions, in situ monitoring of series of experiments on transparent model alloy succinonitrile - 0.24 wt% camphor was carried out under low gravity in the DECLIC Directional Solidification Insert on-board the International Space Station. These experiments offered the very unique opportunity to in situ observe and characterize the whole development of the microstructure in extended 3D patterns. The experimental methods will be first briefly described, including in particular the observation modes and the image analysis procedures developed to quantitatively characterize the patterns. Microgravity environment provided the conditions to get quantitative benchmark data: homogeneous patterns corresponding to homogeneous values of control parameters along the whole interface were obtained. The sequence of microstructure formation will be presented as well as the evolution of the primary spacing which is one of the most important pattern characteristic. Time evolution of this primary spacing during the microstructure development will be analysed to identify the mechanisms of spacing selection and adjustment; the importance of the macroscopic interfacial curvature will be pointed out.
3D fast wavelet network model-assisted 3D face recognition
NASA Astrophysics Data System (ADS)
Said, Salwa; Jemai, Olfa; Zaied, Mourad; Ben Amar, Chokri
2015-12-01
In last years, the emergence of 3D shape in face recognition is due to its robustness to pose and illumination changes. These attractive benefits are not all the challenges to achieve satisfactory recognition rate. Other challenges such as facial expressions and computing time of matching algorithms remain to be explored. In this context, we propose our 3D face recognition approach using 3D wavelet networks. Our approach contains two stages: learning stage and recognition stage. For the training we propose a novel algorithm based on 3D fast wavelet transform. From 3D coordinates of the face (x,y,z), we proceed to voxelization to get a 3D volume which will be decomposed by 3D fast wavelet transform and modeled after that with a wavelet network, then their associated weights are considered as vector features to represent each training face . For the recognition stage, an unknown identity face is projected on all the training WN to obtain a new vector features after every projection. A similarity score is computed between the old and the obtained vector features. To show the efficiency of our approach, experimental results were performed on all the FRGC v.2 benchmark.
Pore-scale intermittent velocity structure underpinning anomalous transport through 3-D porous media
NASA Astrophysics Data System (ADS)
Kang, Peter K.; Anna, Pietro; Nunes, Joao P.; Bijeljic, Branko; Blunt, Martin J.; Juanes, Ruben
2014-09-01
We study the nature of non-Fickian particle transport in 3-D porous media by simulating fluid flow in the intricate pore space of real rock. We solve the full Navier-Stokes equations at the same resolution as the 3-D micro-CT (computed tomography) image of the rock sample and simulate particle transport along the streamlines of the velocity field. We find that transport at the pore scale is markedly anomalous: longitudinal spreading is superdiffusive, while transverse spreading is subdiffusive. We demonstrate that this anomalous behavior originates from the intermittent structure of the velocity field at the pore scale, which in turn emanates from the interplay between velocity heterogeneity and velocity correlation. Finally, we propose a continuous time random walk model that honors this intermittent structure at the pore scale and captures the anomalous 3-D transport behavior at the macroscale.
Transport of 3D space charge dominated beams
NASA Astrophysics Data System (ADS)
Lü, Jian-Qin
2013-10-01
In this paper we present the theoretical analysis and the computer code design for the intense pulsed beam transport. Intense beam dynamics is a very important issue in low-energy high-current accelerators and beam transport systems. This problem affects beam transmission and beam qualities. Therefore, it attracts the attention of the accelerator physicists worldwide. The analysis and calculation for the intense beam dynamics are very complicated, because the state of particle motion is dominated not only by the applied electromagnetic fields, but also by the beam-induced electromagnetic fields (self-fields). Moreover, the self fields are related to the beam dimensions and particle distributions. So, it is very difficult to get the self-consistent solutions of particle motion analytically. For this reason, we combine the Lie algebraic method and the particle in cell (PIC) scheme together to simulate intense 3D beam transport. With the Lie algebraic method we analyze the particle nonlinear trajectories in the applied electromagnetic fields up to third order approximation, and with the PIC algorithm we calculate the space charge effects to the particle motion. Based on the theoretical analysis, we have developed a computer code, which calculates beam transport systems consisting of electrostatic lenses, electrostatic accelerating columns, solenoid lenses, magnetic and electric quadruples, magnetic sextupoles, octopuses and different kinds of electromagnetic analyzers. The optimization calculations and the graphic display for the calculated results are provided by the code.
A 3-D shape model of Interamnia
NASA Astrophysics Data System (ADS)
Sato, Isao
2015-08-01
A 3-D shape model of the sixth largest of the main belt asteroids, (704) Interamnia, is presented. The model is reproduced from its two stellar occultation observations and six lightcurves between 1969 and 2011. The first stellar occultation was the occultation of TYC 234500183 on 1996 December 17 observed from 13 sites in the USA. An elliptical cross section of (344.6±9.6km)×(306.2±9.1km), for position angle P=73.4±12.5 was fitted. The lightcurve around the occultation shows that the peak-to-peak amplitude was 0.04 mag. and the occultation phase was just before the minimum. The second stellar occultation was the occultation of HIP 036189 on 2003 March 23 observed from 39 sites in Japan and Hawaii. An elliptical cross section of (349.8±0.9km)×(303.7±1.7km), for position angle P=86.0±1.1 was fitted. A companion of 8.5 mag. of the occulted star was discovered whose separation is 12±2 mas (milli-arcseconds), P=148±11 . A combined analysis of rotational lightcurves and occultation chords can return more information than can be obtained with either technique alone. From follow-up photometric observations of the asteroid between 2003 and 2011, its rotation period is determined to be 8.728967167±0.00000007 hours, which is accurate enough to fix the rotation phases at other occultation events. The derived north pole is λ2000=259±8, β2000=-50±5 (retrograde rotation); the lengths of the three principal axes are 2a=361.8±2.8km, 2b=324.4±5.0km, 2c=297.3±3.5km, and the mean diameter is D=326.8±3.0km. Supposing the mass of Interamnia as (3.5±0.9)×10-11 solar masses, the density is then ρ=3.8±1.0 g cm-3.
3D Modeling Techniques for Print and Digital Media
NASA Astrophysics Data System (ADS)
Stephens, Megan Ashley
In developing my thesis, I looked to gain skills using ZBrush to create 3D models, 3D scanning, and 3D printing. The models created compared the hearts of several vertebrates and were intended for students attending Comparative Vertebrate Anatomy. I used several resources to create a model of the human heart and was able to work from life while creating heart models from other vertebrates. I successfully learned ZBrush and 3D scanning, and successfully printed 3D heart models. ZBrush allowed me to create several intricate models for use in both animation and print media. The 3D scanning technique did not fit my needs for the project, but may be of use for later projects. I was able to 3D print using two different techniques as well.
Meng, Da; Zheng, Bin; Lin, Guang; Sushko, Maria L.
2014-08-29
We have developed efficient numerical algorithms for the solution of 3D steady-state Poisson-Nernst-Planck equations (PNP) with excess chemical potentials described by the classical density functional theory (cDFT). The coupled PNP equations are discretized by finite difference scheme and solved iteratively by Gummel method with relaxation. The Nernst-Planck equations are transformed into Laplace equations through the Slotboom transformation. Algebraic multigrid method is then applied to efficiently solve the Poisson equation and the transformed Nernst-Planck equations. A novel strategy for calculating excess chemical potentials through fast Fourier transforms is proposed which reduces computational complexity from O(N2) to O(NlogN) where N is the number of grid points. Integrals involving Dirac delta function are evaluated directly by coordinate transformation which yields more accurate result compared to applying numerical quadrature to an approximated delta function. Numerical results for ion and electron transport in solid electrolyte for Li ion batteries are shown to be in good agreement with the experimental data and the results from previous studies.
3D modeling of metallic grain growth
George, D.; Carlson, N.; Gammel, J.T.; Kuprat, A.
1999-06-01
This paper will describe simulating metallic grain growth using the Gradient Weighted Moving Finite Elements code, GRAIN3D. The authors also describe the set of mesh topology change operations developed to respond to changes in the physical topology such as the collapse of grains and to maintain uniform calculational mesh quality. Validation of the method is demonstrated by comparison to analytic calculations. The authors present results of multigrain simulations where grain boundaries evolve by mean curvature motion and include results which incorporate grain boundary orientation dependence.
The 3D rocket combustor acoustics model
NASA Technical Reports Server (NTRS)
Priem, Richard J.; Breisacher, Kevin J.
1992-01-01
The theory and procedures for determining the characteristics of pressure oscillations in rocket engines with prescribed burning rate oscillations are presented. Analyses including radial and hub baffles and absorbers can be performed in one, two, and three dimensions. Pressure and velocity oscillations calculated using this procedure are presented for the SSME to show the influence of baffles and absorbers on the burning rate oscillations required to achieve neutral stability. Comparisons are made between the results obtained utilizing 1-D, 2-D, and 3-D assumptions with regards to capturing the physical phenomena of interest and computational requirements.
SOLIDFELIX: a transportable 3D static volume display
NASA Astrophysics Data System (ADS)
Langhans, Knut; Kreft, Alexander; Wörden, Henrik Tom
2009-02-01
Flat 2D screens cannot display complex 3D structures without the usage of different slices of the 3D model. Volumetric displays like the "FELIX 3D-Displays" can solve the problem. They provide space-filling images and are characterized by "multi-viewer" and "all-round view" capabilities without requiring cumbersome goggles. In the past many scientists tried to develop similar 3D displays. Our paper includes an overview from 1912 up to today. During several years of investigations on swept volume displays within the "FELIX 3D-Projekt" we learned about some significant disadvantages of rotating screens, for example hidden zones. For this reason the FELIX-Team started investigations also in the area of static volume displays. Within three years of research on our 3D static volume display at a normal high school in Germany we were able to achieve considerable results despite minor funding resources within this non-commercial group. Core element of our setup is the display volume which consists of a cubic transparent material (crystal, glass, or polymers doped with special ions, mainly from the rare earth group or other fluorescent materials). We focused our investigations on one frequency, two step upconversion (OFTS-UC) and two frequency, two step upconversion (TFTSUC) with IR-Lasers as excitation source. Our main interest was both to find an appropriate material and an appropriate doping for the display volume. Early experiments were carried out with CaF2 and YLiF4 crystals doped with 0.5 mol% Er3+-ions which were excited in order to create a volumetric pixel (voxel). In addition to that the crystals are limited to a very small size which is the reason why we later investigated on heavy metal fluoride glasses which are easier to produce in large sizes. Currently we are using a ZBLAN glass belonging to the mentioned group and making it possible to increase both the display volume and the brightness of the images significantly. Although, our display is currently
Reactive Transport from Path3D: A Stream Tube Approach for Heterogeneous Aquifers
NASA Astrophysics Data System (ADS)
LI, L.
2001-05-01
Path3D (Zheng, 1991) is a popular computer program run in series with MODFLOW. Remediation engineers and hydrogeologist use it to track contaminant paths and to estimate solute travel time at heterogeneous sites. In order to predict fate and transport of multiple species at heterogeneous sites, numerical modeling packages, such as MT3D (Zheng,1990) or RT3D (Clement 1997) are often employed. These packages also are based on pre-processing with MODFLOW. However, for complex cases with aquifer heterogeneity, MT3D and RT3D often require very long computer run times. This paper addresses a new, stream-tube, approach that is both highly efficient and accurate to predict multi-species reactive transport at heterogeneous sites with steady flow. Our application of the stream tube approach is different from other stream tube approaches that apply the advection-dispersion-reaction equation in each stream tube (such as Ginn, 2000, Yabusaki, 1998, Charbeneau, 2000). In this work, the authors make use of properties of a linear system,working with decoupled reaction and sorption processes and mixing processes described by residence time distributions (RTDs). RTDs are abstracted from Path3D particle-tracking results and additional temporal and spatial dispersion (not caused by aquifer heterogeneity) is ignored. Reactions, including first order reactions and linear, reversible sorption, are applied through analytical transfer functions (called kinetic response functions). Convolution can then be applied to determine contaminant concentrations at monitoring points, using the RTDs determined from Path3D, kinetic transfer functions (expressed analytically), and expected trends of the source concentration. We are currently testing the approach and noting significant computational advantages for problems in three-dimensions, with first order reaction pathways and different retardation factors. We will demonstrate the method with several examples and compare the performance with MT3D and
3D Face Modeling Using the Multi-Deformable Method
Hwang, Jinkyu; Yu, Sunjin; Kim, Joongrock; Lee, Sangyoun
2012-01-01
In this paper, we focus on the problem of the accuracy performance of 3D face modeling techniques using corresponding features in multiple views, which is quite sensitive to feature extraction errors. To solve the problem, we adopt a statistical model-based 3D face modeling approach in a mirror system consisting of two mirrors and a camera. The overall procedure of our 3D facial modeling method has two primary steps: 3D facial shape estimation using a multiple 3D face deformable model and texture mapping using seamless cloning that is a type of gradient-domain blending. To evaluate our method's performance, we generate 3D faces of 30 individuals and then carry out two tests: accuracy test and robustness test. Our method shows not only highly accurate 3D face shape results when compared with the ground truth, but also robustness to feature extraction errors. Moreover, 3D face rendering results intuitively show that our method is more robust to feature extraction errors than other 3D face modeling methods. An additional contribution of our method is that a wide range of face textures can be acquired by the mirror system. By using this texture map, we generate realistic 3D face for individuals at the end of the paper. PMID:23201976
Life in 3D is never flat: 3D models to optimise drug delivery.
Fitzgerald, Kathleen A; Malhotra, Meenakshi; Curtin, Caroline M; O' Brien, Fergal J; O' Driscoll, Caitriona M
2015-10-10
The development of safe, effective and patient-acceptable drug products is an expensive and lengthy process and the risk of failure at different stages of the development life-cycle is high. Improved biopharmaceutical tools which are robust, easy to use and accurately predict the in vivo response are urgently required to help address these issues. In this review the advantages and challenges of in vitro 3D versus 2D cell culture models will be discussed in terms of evaluating new drug products at the pre-clinical development stage. Examples of models with a 3D architecture including scaffolds, cell-derived matrices, multicellular spheroids and biochips will be described. The ability to simulate the microenvironment of tumours and vital organs including the liver, kidney, heart and intestine which have major impact on drug absorption, distribution, metabolism and toxicity will be evaluated. Examples of the application of 3D models including a role in formulation development, pharmacokinetic profiling and toxicity testing will be critically assessed. Although utilisation of 3D cell culture models in the field of drug delivery is still in its infancy, the area is attracting high levels of interest and is likely to become a significant in vitro tool to assist in drug product development thus reducing the requirement for unnecessary animal studies. PMID:26220617
Assessing the RELAPS-3D Heat Conduction Enclosure Model
McCann, Larry D.
2008-09-30
Three heat conduction problems that have exact solutions are modeled with RELAP5-3D using the conduction enclosure model. These comparisons are designed to be used in the RELAP5-3D development assessment scheduled to be completed in 2009. It is shown that with proper input choices and adequate model detail the exact solutions can be matched. In addition, this analysis identified an error and the required correction in the cylindrical and spherical heat conductor models in RELAP5-3D which will be corrected in a future version of RELAP5-3D.
3D scene modeling from multiple range views
NASA Astrophysics Data System (ADS)
Sequeira, Vitor; Goncalves, Joao G. M.; Ribeiro, M. Isabel
1995-09-01
This paper presents a new 3D scene analysis system that automatically reconstructs the 3D geometric model of real-world scenes from multiple range images acquired by a laser range finder on board of a mobile robot. The reconstruction is achieved through an integrated procedure including range data acquisition, geometrical feature extraction, registration, and integration of multiple views. Different descriptions of the final 3D scene model are obtained: a polygonal triangular mesh, a surface description in terms of planar and biquadratics surfaces, and a 3D boundary representation. Relevant experimental results from the complete 3D scene modeling are presented. Direct applications of this technique include 3D reconstruction and/or update of architectual or industrial plans into a CAD model, design verification of buildings, navigation of autonomous robots, and input to virtual reality systems.
Visualization of 3D Geological Models on Google Earth
NASA Astrophysics Data System (ADS)
Choi, Y.; Um, J.; Park, M.
2013-05-01
Google Earth combines satellite imagery, aerial photography, thematic maps and various data sets to make a three-dimensional (3D) interactive image of the world. Currently, Google Earth is a popular visualization tool in a variety of fields and plays an increasingly important role not only for private users in daily life, but also for scientists, practitioners, policymakers and stakeholders in research and application. In this study, a method to visualize 3D geological models on Google Earth is presented. COLLAborative Design Activity (COLLADA, an open standard XML schema for establishing interactive 3D applications) was used to represent different 3D geological models such as borehole, fence section, surface-based 3D volume and 3D grid by triangle meshes (a set of triangles connected by their common edges or corners). In addition, we designed Keyhole Markup Language (KML, the XML-based scripting language of Google Earth) codes to import the COLLADA files into the 3D render window of Google Earth. The method was applied to the Grosmont formation in Alberta, Canada. The application showed that the combination of COLLADA and KML enables Google Earth to effectively visualize 3D geological structures and properties.; Visualization of the (a) boreholes, (b) fence sections, (c) 3D volume model and (d) 3D grid model of Grossmont formation on Google Earth
Comparing a quasi-3D to a full 3D nearshore circulation model: SHORECIRC and ROMS
NASA Astrophysics Data System (ADS)
Haas, Kevin A.; Warner, John C.
Predictions of nearshore and surf zone processes are important for determining coastal circulation, impacts of storms, navigation, and recreational safety. Numerical modeling of these systems facilitates advancements in our understanding of coastal changes and can provide predictive capabilities for resource managers. There exists many nearshore coastal circulation models, however they are mostly limited or typically only applied as depth integrated models. SHORECIRC is an established surf zone circulation model that is quasi-3D to allow the effect of the variability in the vertical structure of the currents while maintaining the computational advantage of a 2DH model. Here we compare SHORECIRC to ROMS, a fully 3D ocean circulation model which now includes a three dimensional formulation for the wave-driven flows. We compare the models with three different test applications for: (i) spectral waves approaching a plane beach with an oblique angle of incidence; (ii) monochromatic waves driving longshore currents in a laboratory basin; and (iii) monochromatic waves on a barred beach with rip channels in a laboratory basin. Results identify that the models are very similar for the depth integrated flows and qualitatively consistent for the vertically varying components. The differences are primarily the result of the vertically varying radiation stress utilized by ROMS and the utilization of long wave theory for the radiation stress formulation in vertical varying momentum balance by SHORECIRC. The quasi-3D model is faster, however the applicability of the fully 3D model allows it to extend over a broader range of processes, temporal, and spatial scales.
Comparing a quasi-3D to a full 3D nearshore circulation model: SHORECIRC and ROMS
Haas, K.A.; Warner, J.C.
2009-01-01
Predictions of nearshore and surf zone processes are important for determining coastal circulation, impacts of storms, navigation, and recreational safety. Numerical modeling of these systems facilitates advancements in our understanding of coastal changes and can provide predictive capabilities for resource managers. There exists many nearshore coastal circulation models, however they are mostly limited or typically only applied as depth integrated models. SHORECIRC is an established surf zone circulation model that is quasi-3D to allow the effect of the variability in the vertical structure of the currents while maintaining the computational advantage of a 2DH model. Here we compare SHORECIRC to ROMS, a fully 3D ocean circulation model which now includes a three dimensional formulation for the wave-driven flows. We compare the models with three different test applications for: (i) spectral waves approaching a plane beach with an oblique angle of incidence; (ii) monochromatic waves driving longshore currents in a laboratory basin; and (iii) monochromatic waves on a barred beach with rip channels in a laboratory basin. Results identify that the models are very similar for the depth integrated flows and qualitatively consistent for the vertically varying components. The differences are primarily the result of the vertically varying radiation stress utilized by ROMS and the utilization of long wave theory for the radiation stress formulation in vertical varying momentum balance by SHORECIRC. The quasi-3D model is faster, however the applicability of the fully 3D model allows it to extend over a broader range of processes, temporal, and spatial scales. ?? 2008 Elsevier Ltd.
a Fast Method for Measuring the Similarity Between 3d Model and 3d Point Cloud
NASA Astrophysics Data System (ADS)
Zhang, Zongliang; Li, Jonathan; Li, Xin; Lin, Yangbin; Zhang, Shanxin; Wang, Cheng
2016-06-01
This paper proposes a fast method for measuring the partial Similarity between 3D Model and 3D point Cloud (SimMC). It is crucial to measure SimMC for many point cloud-related applications such as 3D object retrieval and inverse procedural modelling. In our proposed method, the surface area of model and the Distance from Model to point Cloud (DistMC) are exploited as measurements to calculate SimMC. Here, DistMC is defined as the weighted distance of the distances between points sampled from model and point cloud. Similarly, Distance from point Cloud to Model (DistCM) is defined as the average distance of the distances between points in point cloud and model. In order to reduce huge computational burdens brought by calculation of DistCM in some traditional methods, we define SimMC as the ratio of weighted surface area of model to DistMC. Compared to those traditional SimMC measuring methods that are only able to measure global similarity, our method is capable of measuring partial similarity by employing distance-weighted strategy. Moreover, our method is able to be faster than other partial similarity assessment methods. We demonstrate the superiority of our method both on synthetic data and laser scanning data.
Quasi 3D modeling of water flow in vadose zone and groundwater
NASA Astrophysics Data System (ADS)
Kuznetsov, M.; Yakirevich, A.; Pachepsky, Y. A.; Sorek, S.; Weisbrod, N.
2012-07-01
SummaryThe complexity of subsurface flow systems calls for a variety of concepts leading to the multiplicity of simplified flow models. One habitual simplification is based on the assumption that lateral flow and transport in unsaturated zone are not significant unless the capillary fringe is involved. In such cases the flow and transport in the unsaturated zone above groundwater level can be simulated as a 1D phenomenon, whereas the flow and transport through groundwater are viewed as 2D or 3D phenomena. A new approach for a numerical scheme for 3D variably saturated flow using quasi 3D Richards' equation and finite difference scheme is presented. The corresponding numerical algorithm and the QUASI-3D computer code were developed. Results of the groundwater level simulations were compared with transient laboratory experimental data for 2D data constant-flux infiltration, quasi-3D HYDRUS-MODFLOW numerical model and a FULL-3D numerical model using Richards' equation. Hypothetical 3D examples of infiltration, pumping and groundwater mound dissipation for different spatial-time scales are presented. Water flow simulation for the Alto Piura aquifer (Peru) demonstrates the QUASI-3D model application at the regional scale. Computationally the QUASI-3D code was found to be more efficient by an order of 10-300%, while being accurate with respect to the benchmark fully 3D variable saturation code, when the capillary fringe was considered.
A 3D Geometry Model Search Engine to Support Learning
ERIC Educational Resources Information Center
Tam, Gary K. L.; Lau, Rynson W. H.; Zhao, Jianmin
2009-01-01
Due to the popularity of 3D graphics in animation and games, usage of 3D geometry deformable models increases dramatically. Despite their growing importance, these models are difficult and time consuming to build. A distance learning system for the construction of these models could greatly facilitate students to learn and practice at different…
3-D Modeling of a Nearshore Dye Release
NASA Astrophysics Data System (ADS)
Maxwell, A. R.; Hibler, L. F.; Miller, L. M.
2006-12-01
The usage of computer modeling software in predicting the behavior of a plume discharged into deep water is well established. Nearfield plume spreading in coastal areas with complex bathymetry is less commonly studied; in addition to geometry, some of the difficulties of this environment include: tidal exchange, temperature, and salinity gradients. Although some researchers have applied complex hydrodynamic models to this problem, nearfield regions are typically modeled by calibration of an empirical or expert system model. In the present study, the 3D hydrodynamic model Delft3D-FLOW was used to predict the advective transport from a point release in Sequim Bay, Washington. A nested model approach was used, wherein a coarse model using a mesh extending to nearby tide gages (cell sizes up to 1 km) was run over several tidal cycles in order to provide boundary conditions to a smaller area. The nested mesh (cell sizes up to 30 m) was forced on two open boundaries using the water surface elevation derived from the coarse model. Initial experiments with the uncalibrated model were conducted in order to predict plume propagation based on the best available field data. Field experiments were subsequently carried out by releasing rhodamine dye into the bay at near-peak flood tidal current and near high slack tidal conditions. Surface and submerged releases were carried out from an anchored vessel. Concurrently collected data from the experiment include temperature, salinity, dye concentration, and hyperspectral imagery, collected from boats and aircraft. A REMUS autonomous underwater vehicle was used to measure current velocity and dye concentration at varying depths, as well as to acquire additional bathymetric information. Preliminary results indicate that the 3D hydrodynamic model offers a reasonable prediction of plume propagation speed and shape. A sensitivity analysis is underway to determine the significant factors in effectively using the model as a predictive tool
NASA Astrophysics Data System (ADS)
Zurek, Anna; Witczak, Stanislaw; Kania, Jaroslaw; Wachniew, Przemyslaw; Rozanski, Kazimierz; Dulinski, Marek; Jench, Olga
2013-04-01
Niepolomice Forest. There is a growing concern that continued exploitation of those wells may lead to lowering water table in the Niepolomice Forest area and, as a consequence, may trigger drastic changes in this unique ecosystem. A dedicated study was launched with the main aim to quantify the interaction between Niepolomice Forest, with the focus the Wielkie Bloto fen, and the underlying Bogucice Sands aquifer. The work was pursued along three major lines: (i) vertical profiling of the Wielkie Bloto fen aimed at characterizing chemical and isotope contrast in the shallow groundwater occupying the Quaternary cover in order to identify upward leakage of deeper groundwater in the investigated area, (ii) regular monitoring of flow rate, chemistry and environmental isotopes of the Dluga Woda stream draining the Wielkie Bloto fen, and (iii) 3D modeling of groundwater flow in the vicinity of the Wielkie Bloto fen focusing on quantifying the impact of the Wola Batorska well field on the regional groundwater flow patterns. The results of isotope and chemical analyses confirmed existence of upward seepage of groundwater from the Bogucice Sands aquifer in the area of Wielkie Bloto fen. Preliminary assessment of the water balance of Dluga Woda catchment indicates that the baseflow originating from groundwater seepage is equal approximately 16% of the annual precipitation. Results of 3D flow model applied to the study area indicate that prolonged operation of the well-field Wola Batorska at maximum capacity may lead to substantial lowering of water table in the Niepolomice Forest area and, as a consequence, endanger further existence of this unique GDTE. Acknowledgements. Partial financial support of this work through GENESIS project (http:/www.thegenesisproject.eu) funded by the European Commission 7FP contract 226536, and through statutory funds of the AGH University of Science and Technology (projects No.11.11.140.026 and 11.11.220.01) is kindly acknowledged.
Evaluation of 3D-Jury on CASP7 models
Kaján, László; Rychlewski, Leszek
2007-01-01
Background 3D-Jury, the structure prediction consensus method publicly available in the Meta Server , was evaluated using models gathered in the 7th round of the Critical Assessment of Techniques for Protein Structure Prediction (CASP7). 3D-Jury is an automated expert process that generates protein structure meta-predictions from sets of models obtained from partner servers. Results The performance of 3D-Jury was analysed for three aspects. First, we examined the correlation between the 3D-Jury score and a model quality measure: the number of correctly predicted residues. The 3D-Jury score was shown to correlate significantly with the number of correctly predicted residues, the correlation is good enough to be used for prediction. 3D-Jury was also found to improve upon the competing servers' choice of the best structure model in most cases. The value of the 3D-Jury score as a generic reliability measure was also examined. We found that the 3D-Jury score separates bad models from good models better than the reliability score of the original server in 27 cases and falls short of it in only 5 cases out of a total of 38. We report the release of a new Meta Server feature: instant 3D-Jury scoring of uploaded user models. Conclusion The 3D-Jury score continues to be a good indicator of structural model quality. It also provides a generic reliability score, especially important for models that were not assigned such by the original server. Individual structure modellers can also benefit from the 3D-Jury scoring system by testing their models in the new instant scoring feature available in the Meta Server. PMID:17711571
NASA Technical Reports Server (NTRS)
Ott, Lesley E.; Pickering, Kenneth E.; Stenchikov, Georgiy L.; Huntrieser, Heidi; Schumann, Ulrich
2006-01-01
The July 21,1998 thunderstonn observed during the European Lightning Nitrogen Oxides Project (EULINOX) project was simulated using the three-dimensional Goddard Cumulus Ensemble (GCE) model. The simulation successfully reproduced a number of observed storm features including the splitting of the original cell into a southern cell which developed supercell characteristics, and a northern cell which became multicellular. Output from the GCE simulation was used to drive an offline cloud-scale chemical transport model which calculates tracer transport and includes a parameterization of lightning NO(x) production which uses observed flash rates as input. Estimates of lightning NO(x) production were deduced by assuming various values of production per intracloud and production per cloud-to-ground flash and comparing the results with in-cloud aircraft observations. The assumption that both types of flashes produce 360 moles of NO per flash on average compared most favorably with column mass and probability distribution functions calculated from observations. This assumed production per flash corresponds to a global annual lightning NOx source of 7 Tg N per yr. Chemical reactions were included in the model to evaluate the impact of lightning NO(x), on ozone. During the storm, the inclusion of lightning NOx in the model results in a small loss of ozone (on average less than 4 ppbv) at all model levels. Simulations of the chemical environment in the 24 hours following the storm show on average a small increase in the net production of ozone at most levels resulting from lightning NO(x), maximizing at approximately 5 ppbv per day at 5.5 km. Between 8 and 10.5 km, lightning NO(x) causes decreased net ozone production.
Stochastic Modeling of Calcium in 3D Geometry
Mazel, Tomáš; Raymond, Rebecca; Raymond-Stintz, Mary; Jett, Stephen; Wilson, Bridget S.
2009-01-01
Release of inflammatory mediators by mast cells in type 1 immediate-hypersensitivity allergic reactions relies on antigen-dependent increases in cytosolic calcium. Here, we used a series of electron microscopy images to build a 3D reconstruction representing a slice through a rat tumor mast cell, which then served as a basis for stochastic modeling of inositol-trisphosphate-mediated calcium responses. The stochastic approach was verified by reaction-diffusion modeling within the same geometry. Local proximity of the endoplasmic reticulum to either the plasma membrane or mitochondria is predicted to differentially impact local inositol trisphosphate receptor transport. The explicit consideration of organelle spatial relationships represents an important step toward building a comprehensive, realistic model of cellular calcium dynamics. PMID:19254531
NASA Astrophysics Data System (ADS)
Bertrand, Tanguy; Forget, Francois
2016-04-01
To interpret New Horizons observations and simulate the Pluto climate system, we have developed a Global Climate Model (GCM) of Pluto's atmosphere. In addition to a 3D "dynamical core" which solves the equation of meteorology, the model takes into account the N2 condensation and sublimation and its thermal and dynamical effects, the vertical turbulent mixing, the radiative transfer through methane and carbon monoxide, molecular thermal conduction, and a detailed surface thermal model with different thermal inertia for various timescales (diurnal, seasonal). The GCM also includes a detailed model of the CH4 and CO cycles, taking into account their transport by the atmospheric circulation and turbulence, as well as their condensation and sublimation on the surface and in the atmosphere, possibly forming methane ice clouds. The GCM consistently predicts the 3D methane abundance in the atmosphere, which is used as an input for our radiative transfer calculation. In a second phase, we also developed a volatile transport model, derived from the GCM, which can be run over thousands of years in order to reach consistent initial states for the GCM runs and better explore the seasonal processes on Pluto. Results obtained with the volatile transport model show that the distribution of N2, CH4 and CO ices primarily depends on the seasonal thermal inertia used for the different ices, and is affected by the assumed topography as well. As observed, it is possible to form a large and permanent nitrogen glacier with CO and CH4 ice deposits in an equatorial basin corresponding to Sputnik Planum, while having a surface pressure evolution consistent with stellar occultations and New Horizons data. In addition, most of the methane ice is sequestered with N2 ice in the basin but seasonal polar caps of CH4 frosts also form explaining the bright polar caps observed with Hubble in the 1980s and in line with New Horizons observations. Using such balanced combination of surface and
Computational modeling of RNA 3D structures and interactions.
Dawson, Wayne K; Bujnicki, Janusz M
2016-04-01
RNA molecules have key functions in cellular processes beyond being carriers of protein-coding information. These functions are often dependent on the ability to form complex three-dimensional (3D) structures. However, experimental determination of RNA 3D structures is difficult, which has prompted the development of computational methods for structure prediction from sequence. Recent progress in 3D structure modeling of RNA and emerging approaches for predicting RNA interactions with ions, ligands and proteins have been stimulated by successes in protein 3D structure modeling. PMID:26689764
An Automated 3d Indoor Topological Navigation Network Modelling
NASA Astrophysics Data System (ADS)
Jamali, A.; Rahman, A. A.; Boguslawski, P.; Gold, C. M.
2015-10-01
Indoor navigation is important for various applications such as disaster management and safety analysis. In the last decade, indoor environment has been a focus of wide research; that includes developing techniques for acquiring indoor data (e.g. Terrestrial laser scanning), 3D indoor modelling and 3D indoor navigation models. In this paper, an automated 3D topological indoor network generated from inaccurate 3D building models is proposed. In a normal scenario, 3D indoor navigation network derivation needs accurate 3D models with no errors (e.g. gap, intersect) and two cells (e.g. rooms, corridors) should touch each other to build their connections. The presented 3D modeling of indoor navigation network is based on surveying control points and it is less dependent on the 3D geometrical building model. For reducing time and cost of indoor building data acquisition process, Trimble LaserAce 1000 as surveying instrument is used. The modelling results were validated against an accurate geometry of indoor building environment which was acquired using Trimble M3 total station.
Highway 3D model from image and lidar data
NASA Astrophysics Data System (ADS)
Chen, Jinfeng; Chu, Henry; Sun, Xiaoduan
2014-05-01
We present a new method of highway 3-D model construction developed based on feature extraction in highway images and LIDAR data. We describe the processing road coordinate data that connect the image frames to the coordinates of the elevation data. Image processing methods are used to extract sky, road, and ground regions as well as significant objects (such as signs and building fronts) in the roadside for the 3D model. LIDAR data are interpolated and processed to extract the road lanes as well as other features such as trees, ditches, and elevated objects to form the 3D model. 3D geometry reasoning is used to match the image features to the 3D model. Results from successive frames are integrated to improve the final model.
Simulation of 3D infrared scenes using random fields model
NASA Astrophysics Data System (ADS)
Shao, Xiaopeng; Zhang, Jianqi
2001-09-01
Analysis and simulation of smart munitions requires imagery for the munition's sensor to view. The traditional infrared background simulations are always limited in the plane scene studies. A new method is described to synthesize the images in 3D view and with various terrains texture. We develop the random fields model and temperature fields to simulate 3D infrared scenes. Generalized long-correlation (GLC) model, one of random field models, will generate both the 3D terrains skeleton data and the terrains texture in this work. To build the terrain mesh with the random fields, digital elevation models (DEM) are introduced in the paper. And texture mapping technology will perform the task of pasting the texture in the concavo-convex surfaces of the 3D scene. The simulation using random fields model is a very available method to produce 3D infrared scene with great randomicity and reality.
An Automatic Registration Algorithm for 3D Maxillofacial Model
NASA Astrophysics Data System (ADS)
Qiu, Luwen; Zhou, Zhongwei; Guo, Jixiang; Lv, Jiancheng
2016-09-01
3D image registration aims at aligning two 3D data sets in a common coordinate system, which has been widely used in computer vision, pattern recognition and computer assisted surgery. One challenging problem in 3D registration is that point-wise correspondences between two point sets are often unknown apriori. In this work, we develop an automatic algorithm for 3D maxillofacial models registration including facial surface model and skull model. Our proposed registration algorithm can achieve a good alignment result between partial and whole maxillofacial model in spite of ambiguous matching, which has a potential application in the oral and maxillofacial reparative and reconstructive surgery. The proposed algorithm includes three steps: (1) 3D-SIFT features extraction and FPFH descriptors construction; (2) feature matching using SAC-IA; (3) coarse rigid alignment and refinement by ICP. Experiments on facial surfaces and mandible skull models demonstrate the efficiency and robustness of our algorithm.
Qiang, J.; Leitner, D.; Todd, D.
2005-05-16
The driver linac of the proposed Rare Isotope Accelerator (RIA) requires a great variety of high intensity, high charge state ion beams. In order to design and to optimize the low energy beamline optics of the RIA front end,we have developed a new parallel three-dimensional model to simulate the low energy, multi-species ion beam formation and transport from the ECR ion source extraction region to the focal plane of the analyzing magnet. A multisection overlapped computational domain has been used to break the original transport system into a number of each subsystem, macro-particle tracking is used to obtain the charge density distribution in this subdomain. The three-dimensional Poisson equation is solved within the subdomain and particle tracking is repeated until the solution converges. Two new Poisson solvers based on a combination of the spectral method and the multigrid method have been developed to solve the Poisson equation in cylindrical coordinates for the beam extraction region and in the Frenet-Serret coordinates for the bending magnet region. Some test examples and initial applications will also be presented.
Extending 3D city models with legal information
NASA Astrophysics Data System (ADS)
Frank, A. U.; Fuhrmann, T.; Navratil, G.
2012-10-01
3D city models represent existing physical objects and their topological and functional relations. In everyday life the rights and responsibilities connected to these objects, primarily legally defined rights and obligations but also other socially and culturally established rights, are of importance. The rights and obligations are defined in various laws and it is often difficult to identify the rules applicable for a certain case. The existing 2D cadastres show civil law rights and obligations and plans to extend them to provide information about public law restrictions for land use are in several countries under way. It is tempting to design extensions to the 3D city models to provide information about legal rights in 3D. The paper analyses the different types of information that are needed to reduce conflicts and to facilitate decisions about land use. We identify the role 3D city models augmented with planning information in 3D can play, but do not advocate a general conversion from 2D to 3D for the legal cadastre. Space is not anisotropic and the up/down dimension is practically very different from the two dimensional plane - this difference must be respected when designing spatial information systems. The conclusions are: (1) continue the current regime for ownership of apartments, which is not ownership of a 3D volume, but co-ownership of a building with exclusive use of some rooms; such exclusive use rights could be shown in a 3D city model; (2) ownership of 3D volumes for complex and unusual building situations can be reported in a 3D city model, but are not required everywhere; (3) indicate restrictions for land use and building in 3D city models, with links to the legal sources.
3D scanning modeling method application in ancient city reconstruction
NASA Astrophysics Data System (ADS)
Ren, Pu; Zhou, Mingquan; Du, Guoguang; Shui, Wuyang; Zhou, Pengbo
2015-07-01
With the development of optical engineering technology, the precision of 3D scanning equipment becomes higher, and its role in 3D modeling is getting more distinctive. This paper proposed a 3D scanning modeling method that has been successfully applied in Chinese ancient city reconstruction. On one hand, for the existing architectures, an improved algorithm based on multiple scanning is adopted. Firstly, two pieces of scanning data were rough rigid registered using spherical displacers and vertex clustering method. Secondly, a global weighted ICP (iterative closest points) method is used to achieve a fine rigid registration. On the other hand, for the buildings which have already disappeared, an exemplar-driven algorithm for rapid modeling was proposed. Based on the 3D scanning technology and the historical data, a system approach was proposed for 3D modeling and virtual display of ancient city.
3-D model-based Bayesian classification
Soenneland, L.; Tenneboe, P.; Gehrmann, T.; Yrke, O.
1994-12-31
The challenging task of the interpreter is to integrate different pieces of information and combine them into an earth model. The sophistication level of this earth model might vary from the simplest geometrical description to the most complex set of reservoir parameters related to the geometrical description. Obviously the sophistication level also depend on the completeness of the available information. The authors describe the interpreter`s task as a mapping between the observation space and the model space. The information available to the interpreter exists in observation space and the task is to infer a model in model-space. It is well-known that this inversion problem is non-unique. Therefore any attempt to find a solution depend son constraints being added in some manner. The solution will obviously depend on which constraints are introduced and it would be desirable to allow the interpreter to modify the constraints in a problem-dependent manner. They will present a probabilistic framework that gives the interpreter the tools to integrate the different types of information and produce constrained solutions. The constraints can be adapted to the problem at hand.
Opportunity Landing Spot Panorama (3-D Model)
NASA Technical Reports Server (NTRS)
2004-01-01
The rocky outcrop traversed by the Mars Exploration Rover Opportunity is visible in this three-dimensional model of the rover's landing site. Opportunity has acquired close-up images along the way, and scientists are using the rover's instruments to closely examine portions of interest. The white fragments that look crumpled near the center of the image are portions of the airbags. Distant scenery is displayed on a spherical backdrop or 'billboard' for context. Artifacts near the top rim of the crater are a result of the transition between the three-dimensional model and the billboard. Portions of the terrain model lacking sufficient data appear as blank spaces or gaps, colored reddish-brown for better viewing. This image was generated using special software from NASA's Ames Research Center and a mosaic of images taken by the rover's panoramic camera.
[figure removed for brevity, see original site] Click on image for larger view
The rocky outcrop traversed by the Mars Exploration Rover Opportunity is visible in this zoomed-in portion of a three-dimensional model of the rover's landing site. Opportunity has acquired close-up images along the way, and scientists are using the rover's instruments to closely examine portions of interest. The white fragments that look crumpled near the center of the image are portions of the airbags. Distant scenery is displayed on a spherical backdrop or 'billboard' for context. Artifacts near the top rim of the crater are a result of the transition between the three-dimensional model and the billboard. Portions of the terrain model lacking sufficient data appear as blank spaces or gaps, colored reddish-brown for better viewing. This image was generated using special software from NASA's Ames Research Center and a mosaic of images taken by the rover's panoramic camera.
Venusian Applications of 3D Convection Modeling
NASA Technical Reports Server (NTRS)
Bonaccorso, Timary Annie
2011-01-01
This study models mantle convection on Venus using the 'cubed sphere' code OEDIPUS, which models one-sixth of the planet in spherical geometry. We are attempting to balance internal heating, bottom mantle viscosity, and temperature difference across Venus' mantle, in order to create a realistic model that matches with current planetary observations. We also have begun to run both lower and upper mantle simulations to determine whether layered (as opposed to whole-mantle) convection might produce more efficient heat transfer, as well as to model coronae formation in the upper mantle. Upper mantle simulations are completed using OEDIPUS' Cartesian counterpart, JOCASTA. This summer's central question has been how to define a mantle plume. Traditionally, we have defined a hot plume the region with temperature at or above 40% of the difference between the maximum and horizontally averaged temperature, and a cold plume as the region with 40% of the difference between the minimum and average temperature. For less viscous cases (1020 Pa?s), the plumes generated by that definition lacked vigor, displaying buoyancies 1/100th of those found in previous, higher viscosity simulations (1021 Pa?s). As the mantle plumes with large buoyancy flux are most likely to produce topographic uplift and volcanism, the low viscosity cases' plumes may not produce observable deformation. In an effort to eliminate the smallest plumes, we experimented with different lower bound parameters and temperature percentages.
James E. Fisher; Cliff B. Davis; Walter L. Weaver
2005-06-01
A compressor model has been implemented in the RELAP5-3D© code. The model is similar to that of the existing pump model, and performs the same function on a gas as the pump performs on a single-phase or two-phase fluid. The compressor component consists of an inlet junction and a control volume, and optionally, an outlet junction. This feature permits cascading compressor components in series. The equations describing the physics of the compressor are derived from first principles. These equations are used to obtain the head, the torque, and the energy dissipation. Compressor performance is specified using a map, specific to the design of the machine, in terms of the ratio of outlet-to-inlet total (or stagnation) pressure and adiabatic efficiency as functions of rotational velocity and flow rate. The input quantities are specified in terms of dimensionless variables, which are corrected to stagnation density and stagnation sound speed. A small correction was formulated for the input of efficiency to account for the error introduced by assumption of constant density when integrating the momentum equation. Comparison of the results of steady-state operation of the compressor model to those of the MIT design calculation showed excellent agreement for both pressure ratio and power.
Image based 3D city modeling : Comparative study
NASA Astrophysics Data System (ADS)
Singh, S. P.; Jain, K.; Mandla, V. R.
2014-06-01
3D city model is a digital representation of the Earth's surface and it's related objects such as building, tree, vegetation, and some manmade feature belonging to urban area. The demand of 3D city modeling is increasing rapidly for various engineering and non-engineering applications. Generally four main image based approaches were used for virtual 3D city models generation. In first approach, researchers were used Sketch based modeling, second method is Procedural grammar based modeling, third approach is Close range photogrammetry based modeling and fourth approach is mainly based on Computer Vision techniques. SketchUp, CityEngine, Photomodeler and Agisoft Photoscan are the main softwares to represent these approaches respectively. These softwares have different approaches & methods suitable for image based 3D city modeling. Literature study shows that till date, there is no complete such type of comparative study available to create complete 3D city model by using images. This paper gives a comparative assessment of these four image based 3D modeling approaches. This comparative study is mainly based on data acquisition methods, data processing techniques and output 3D model products. For this research work, study area is the campus of civil engineering department, Indian Institute of Technology, Roorkee (India). This 3D campus acts as a prototype for city. This study also explains various governing parameters, factors and work experiences. This research work also gives a brief introduction, strengths and weakness of these four image based techniques. Some personal comment is also given as what can do or what can't do from these softwares. At the last, this study shows; it concluded that, each and every software has some advantages and limitations. Choice of software depends on user requirements of 3D project. For normal visualization project, SketchUp software is a good option. For 3D documentation record, Photomodeler gives good result. For Large city
NoSQL Based 3D City Model Management System
NASA Astrophysics Data System (ADS)
Mao, B.; Harrie, L.; Cao, J.; Wu, Z.; Shen, J.
2014-04-01
To manage increasingly complicated 3D city models, a framework based on NoSQL database is proposed in this paper. The framework supports import and export of 3D city model according to international standards such as CityGML, KML/COLLADA and X3D. We also suggest and implement 3D model analysis and visualization in the framework. For city model analysis, 3D geometry data and semantic information (such as name, height, area, price and so on) are stored and processed separately. We use a Map-Reduce method to deal with the 3D geometry data since it is more complex, while the semantic analysis is mainly based on database query operation. For visualization, a multiple 3D city representation structure CityTree is implemented within the framework to support dynamic LODs based on user viewpoint. Also, the proposed framework is easily extensible and supports geoindexes to speed up the querying. Our experimental results show that the proposed 3D city management system can efficiently fulfil the analysis and visualization requirements.
Modelling Polymer Deformation during 3D Printing
NASA Astrophysics Data System (ADS)
McIlroy, Claire; Olmsted, Peter
Three-dimensional printing has the potential to transform manufacturing processes, yet improving the strength of printed parts, to equal that of traditionally-manufactured parts, remains an underlying issue. The fused deposition modelling technique involves melting a thermoplastic, followed by layer-by-layer extrusion to fabricate an object. The key to ensuring strength at the weld between layers is successful inter-diffusion. However, prior to welding, both the extrusion process and the cooling temperature profile can significantly deform the polymer micro-structure and, consequently, how well the polymers are able to ``re-entangle'' across the weld. In particular, polymer alignment in the flow can cause de-bonding of the layers and create defects. We have developed a simple model of the non-isothermal extrusion process to explore the effects that typical printing conditions and material rheology have on the conformation of a polymer melt. In particular, we incorporate both stretch and orientation using the Rolie-Poly constitutive equation to examine the melt structure as it flows through the nozzle, the subsequent alignment with the build plate and the resulting deformation due to the fixed nozzle height, which is typically less than the nozzle radius.
NASA Astrophysics Data System (ADS)
da Câmara Santa Clara Gomes, Tristan; De La Torre Medina, Joaquín; Velázquez-Galván, Yenni G.; Martínez-Huerta, Juan Manuel; Encinas, Armando; Piraux, Luc
2016-07-01
We have explored the interplay between the magnetic and magneto-transport properties of 3D interconnected nanowire networks made of various magnetic metals by electrodeposition into nanoporous membranes with crossed channels and controlled topology. The close relationship between their magnetic and structural properties has a direct impact on their magneto-transport behavior. In order to accurately and reliably describe the effective magnetic anisotropy and anisotropic magnetoresistance, an analytical model inherent to the topology of 3D nanowire networks is proposed and validated. The feasibility to obtain magneto-transport responses in nanowire network films based on interconnected nanowires makes them very attractive for the development of mechanically stable superstructures that are suitable for potential technological applications.
NASA Astrophysics Data System (ADS)
Przyborska, Anna; Kosecki, Szymon; Jakacki, Jaromir
2014-05-01
Kongsfjorden is a West Svalbard fjord with a surface area of about 210 km2. It is obvious that the depths of the outer and central basins are influenced by the open sea, under influence of West Spitsbergen Current (WSC), which curry out warm Atlantic water and cold East Spitsbergen Current, while the shallower, inner basin has a large glacial outflow and its maximum depths do not exceed 100 m. Freshwater stored in Spitsbergen glaciers have strong influence on local hydrology and physical fjord conditions. Both, local and shelf conditions have impact on state of the fjord. External forces like tides, velocities at the boundary and atmospheric forces together with sources of cold and dens fresh water in the fjords will give reliable representation of physical conditions in Kongsfjorden. Modeling could help to solve this problem and we have hope that we find answer which one is the most important for local conditions in fjord. Calculations of balances between cold fresh water and warm and salt will provide additional information that could help to answer the main question of the GAME (Growing of the Arctic Marine Ecosystem) project - what is the reaction of physically controlled Arctic marine ecosystem to temperature rise.
3D PIC Modeling of Microcavity Discharge
NASA Astrophysics Data System (ADS)
Hopkins, Matthew; Manginell, Ronald; Moore, Christopher; Yee, Benjamin; Moorman, Matthew
2015-09-01
We present a number of techniques and challenges in simulating the transient behavior of a microcavity discharge. Our microcavities are typically cylindrical with diameters approximately 50 - 100 μm, heights of 50 - 200 μm, pressure near atmospheric, and operate at a few hundred volts. We employ a fully kinetic simulation methodology, the Particle-in-Cell (PIC) method, with interparticle collisions handled via methods based on direct simulation Monte Carlo (DSMC). In particular, we explicitly include kinetic electrons. Some of the challenges we encounter include variations in number densities, external circuit coupling, and time step resolution constraints. By employing dynamic particle weighting (particle weights vary over time by species and location) we can mitigate some of the challenges modeling systems with 107 variations in number densities. Smoothing mechanisms have been used to attempt to mitigate external circuit response. We perform our simulations on hundreds or thousands of processing cores to accommodate the computational work inherent in using relatively small time step sizes (e.g., 50 fs for a 100 ns calculation). In addition, particle weighting issues inherent to three-dimensional low temperature plasma systems will be mentioned. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's NNSA under Contract DE-AC04-94AL85000.
NASA Astrophysics Data System (ADS)
Wu, Jialin; Li, Keqiang; Shi, Xiaoyong; Liang, Shengkang; Han, Xiurong; Ma, Qimin; Wang, Xiulin
2014-08-01
The rapid economic and social developments in the Luoyuan and Lianjiang counties of Fujian Province, China, raise certain environment and ecosystem issues. The unusual phytoplankton bloom and eutrophication, for example, have increased in severity in Luoyuan Bay (LB). The constant increase of nutrient loads has largely caused the environmental degradation in LB. Several countermeasures have been implemented to solve these environmental problems. The most effective of these strategies is the reduction of pollutant loadings into the sea in accordance with total pollutant load control (TPLC) plans. A combined three-dimensional hydrodynamic transport-transformation model was constructed to estimate the marine environmental capacity of chemical oxygen demand (COD). The allowed maximum loadings for each discharge unit in LB were calculated with applicable simulation results. The simulation results indicated that the environmental capacity of COD is approximately 11×104 t year-1 when the water quality complies with the marine functional zoning standards for LB. A pollutant reduction scheme to diminish the present levels of mariculture- and domestic-based COD loadings is based on the estimated marine COD environmental capacity. The obtained values imply that the LB waters could comply with the targeted water quality criteria. To meet the revised marine functional zoning standards, discharge loadings from discharge units 1 and 11 should be reduced to 996 and 3236 t year-1, respectively.
The 3D model: explaining densification and deformation mechanisms by using 3D parameter plots.
Picker, Katharina M
2004-04-01
The aim of the study was to analyze very differently deforming materials using 3D parameter plots and consequently to gain deeper insights into the densification and deformation process described with the 3D model in order to define an ideal tableting excipient. The excipients used were dicalcium phosphate dihydrate (DCPD), sodium chloride (NaCl), microcrystalline cellulose (MCC), xylitol, mannitol, alpha-lactose monohydrate, maltose, hydroxypropyl methylcellulose (HPMC), sodium carboxymethylcellulose (NaCMC), cellulose acetate (CAC), maize starch, potato starch, pregelatinized starch, and maltodextrine. All of the materials were tableted to graded maximum relative densities (rhorel, max) using an eccentric tableting machine. The data which resulted, namely force, displacement, and time, were analyzed by the application of 3D modeling. Different particle size fractions of DCPD, CAC, and MCC were analyzed in addition. Brittle deforming materials such as DCPD exhibited a completely different 3D parameter plot, with low time plasticity, d, and low pressure plasticity, e, and a strong decrease in omega values when densification increased, in contrast to the plastically deforming MCC, which had much higher d, e, and omega values. e and omega values changed only slightly when densification increased for MCC. NaCl showed less of a decrease in omega values than DCPD did, and the d and e values were between those of MCC and DCPD. The sugar alcohols, xylitol and mannitol, behaved in a similar fashion to sodium chloride. This is also valid for the crystalline sugars, alpha-lactose monohydrate, and maltose. However, the sugars are more brittle than the sugar alcohols. The cellulose derivatives, HPMC, NaCMC, and CAC, are as plastic as MCC, however, their elasticity depends on substitution indicated by lower (more elastic) or higher (less elastic) omega values. The native starches, maize starch and potato starch, are very elastic, and pregelatinized starch and maltodextrine are
Impact of 3D root uptake on solute transport: a numerical study
NASA Astrophysics Data System (ADS)
Schröder, N.; Javaux, M.; Vanderborght, J.; Steffen, B.; Vereecken, H.
2011-12-01
Plant transpiration is an important component of the hydrological cycle. Through root water uptake, plants do not only affect the 3D soil water flow velocity distribution, but also solute movement in soil. This numerical study aims at investigating how solute fate is impacted by root uptake using the 3D biophysical model R-SWMS (Javaux et al., 2008). This model solves the Richards equation in 3D in the soil and the flow equation within the plant root xylem vessels. Furthermore, for solute transport simulations, the 3D particle tracker PARTRACE (Bechtold et al., 2011) was used. . We generated 3D virtual steady-state breakthrough curves (BTC) experiments in soils with transpiring plants. The averaged BTCs were then fitted with a 1D numerical flow model under steady-state conditions to obtain apparent CDE parameters. Two types of root architecture, a fibrous and a taprooted structure, were compared in virtual 3D experiments. The solute uptake type or the transpiration rate were also modified and we analyzed how these parameters affected apparent disperisivity and velocity profiles. Our simulation results show, that both, apparent velocity and dispersivity length are affected by water and solute root uptake. In addition, under high exclusion processes (slight or no active uptake), solute accumulates around roots and generates a long tailing to the breakthrough curves, which cannot be reproduced by 1D models that simulate root water uptake with solute exclusion. This observation may have an important impact on how to model pollutant mass transfer to groundwater at larger scales. Javaux, M., T. Schröder, J. Vanderborght, and H. Vereecken. 2008. Use of a three-dimensional detailed modeling approach for predicting root water uptake. Vadose Zone J. 7:1079-1088.doi: 10.2136/vzj2007.0115. Bechtold, M., S. Haber-Pohlmeier, J. Vanderborght, A. Pohlmeier, P.A. Ferre, and H. Vereecken. 2011. Near-surface solute redistribution during evaporation. Submitted to Geophys. Res. Lett
3D-model building of the jaw impression
NASA Astrophysics Data System (ADS)
Ahmed, Moumen T.; Yamany, Sameh M.; Hemayed, Elsayed E.; Farag, Aly A.
1997-03-01
A novel approach is proposed to obtain a record of the patient's occlusion using computer vision. Data acquisition is obtained using intra-oral video cameras. The technique utilizes shape from shading to extract 3D information from 2D views of the jaw, and a novel technique for 3D data registration using genetic algorithms. The resulting 3D model can be used for diagnosis, treatment planning, and implant purposes. The overall purpose of this research is to develop a model-based vision system for orthodontics to replace traditional approaches. This system will be flexible, accurate, and will reduce the cost of orthodontic treatments.
3D model-based still image object categorization
NASA Astrophysics Data System (ADS)
Petre, Raluca-Diana; Zaharia, Titus
2011-09-01
This paper proposes a novel recognition scheme algorithm for semantic labeling of 2D object present in still images. The principle consists of matching unknown 2D objects with categorized 3D models in order to infer the semantics of the 3D object to the image. We tested our new recognition framework by using the MPEG-7 and Princeton 3D model databases in order to label unknown images randomly selected from the web. Results obtained show promising performances, with recognition rate up to 84%, which opens interesting perspectives in terms of semantic metadata extraction from still images/videos.
Summary on Several Key Techniques in 3D Geological Modeling
2014-01-01
Several key techniques in 3D geological modeling including planar mesh generation, spatial interpolation, and surface intersection are summarized in this paper. Note that these techniques are generic and widely used in various applications but play a key role in 3D geological modeling. There are two essential procedures in 3D geological modeling: the first is the simulation of geological interfaces using geometric surfaces and the second is the building of geological objects by means of various geometric computations such as the intersection of surfaces. Discrete geometric surfaces that represent geological interfaces can be generated by creating planar meshes first and then spatially interpolating; those surfaces intersect and then form volumes that represent three-dimensional geological objects such as rock bodies. In this paper, the most commonly used algorithms of the key techniques in 3D geological modeling are summarized. PMID:24772029
Formal representation of 3D structural geological models
NASA Astrophysics Data System (ADS)
Wang, Zhangang; Qu, Honggang; Wu, Zixing; Yang, Hongjun; Du, Qunle
2016-05-01
The development and widespread application of geological modeling methods has increased demands for the integration and sharing services of three dimensional (3D) geological data. However, theoretical research in the field of geological information sciences is limited despite the widespread use of Geographic Information Systems (GIS) in geology. In particular, fundamental research on the formal representations and standardized spatial descriptions of 3D structural models is required. This is necessary for accurate understanding and further applications of geological data in 3D space. In this paper, we propose a formal representation method for 3D structural models using the theory of point set topology, which produces a mathematical definition for the major types of geological objects. The spatial relationships between geologic boundaries, structures, and units are explained in detail using the 9-intersection model. Reasonable conditions for describing the topological space of 3D structural models are also provided. The results from this study can be used as potential support for the standardized representation and spatial quality evaluation of 3D structural models, as well as for specific needs related to model-based management, query, and analysis.
Metrological validation for 3D modeling of dental plaster casts.
Brusco, Nicola; Andreetto, Marco; Lucchese, Luca; Carmignato, Simone; Cortelazzo, Guido M
2007-11-01
The contribution of this paper is twofold: (1) it presents an automatic 3D modeling technique and (2) it advances a procedure for its metrological evaluation in the context of a medical application, the 3D modeling of dental plaster casts. The motivation for this work is the creation of a "virtual gypsotheque" where cumbersome dental plaster casts can be replaced by numerical 3D models, thereby alleviating storage and access problems and allowing dentists and orthodontists the use of novel and unprecedented software tools for their medical evaluations. Modeling free-form surfaces of anatomical interest is an intriguing mixture of open issues concerning 3D modeling, geometrical metrology, and medicine. Of general interest is both the fact that a widespread use of 3D modeling in non-engineering applications requires automatic procedures of the kind presented in this work and the adopted validation paradigm for free-form surfaces, rather useful for practical purposes. In this latter respect, the metrological analysis we advance is the first seminal attempt in the field of 3D modeling and can be readily extended to contexts other than the medical one discussed in this paper. PMID:17126062
3D Modeling from Photos Given Topological Information.
Kim, Young Min; Cho, Junghyun; Ahn, Sang Chul
2016-09-01
Reconstructing 3D models given a single-view 2D information is inherently an ill-posed problem and requires additional information such as shape prior or user input.We introduce a method to generate multiple 3D models of a particular category given corresponding photographs when the topological information is known. While there is a wide range of shapes for an object of a particular category, the basic topology usually remains constant.In consequence, the topological prior needs to be provided only once for each category and can be easily acquired by consulting an existing database of 3D models or by user input. The input of topological description is only connectivity information between parts; this is in contrast to previous approaches that have required users to interactively mark individual parts. Given the silhouette of an object and the topology, our system automatically finds a skeleton and generates a textured 3D model by jointly fitting multiple parts. The proposed method, therefore, opens the possibility of generating a large number of 3D models by consulting a massive number of photographs. We demonstrate examples of the topological prior and reconstructed 3D models using photos. PMID:26661474
Performance Evaluation of 3d Modeling Software for Uav Photogrammetry
NASA Astrophysics Data System (ADS)
Yanagi, H.; Chikatsu, H.
2016-06-01
UAV (Unmanned Aerial Vehicle) photogrammetry, which combines UAV and freely available internet-based 3D modeling software, is widely used as a low-cost and user-friendly photogrammetry technique in the fields such as remote sensing and geosciences. In UAV photogrammetry, only the platform used in conventional aerial photogrammetry is changed. Consequently, 3D modeling software contributes significantly to its expansion. However, the algorithms of the 3D modelling software are black box algorithms. As a result, only a few studies have been able to evaluate their accuracy using 3D coordinate check points. With this motive, Smart3DCapture and Pix4Dmapper were downloaded from the Internet and commercial software PhotoScan was also employed; investigations were performed in this paper using check points and images obtained from UAV.
The Lagrangian method provides estimates of the chemical and physical evolution of air arriving in the daytime boundary layer at Baltimore. Study results indicate a dominant role for regional transport contributions of those days when sulfate air pollution is highest in Baltimor...
NASA Technical Reports Server (NTRS)
Davis, Anthony B.; Marshak, Alexander
2010-01-01
The interplay of sunlight with clouds is a ubiquitous and often pleasant visual experience, but it conjures up major challenges for weather, climate, environmental science and beyond. Those engaged in the characterization of clouds (and the clear air nearby) by remote sensing methods are even more confronted. The problem comes, on the one hand, from the spatial complexity of real clouds and, on the other hand, from the dominance of multiple scattering in the radiation transport. The former ingredient contrasts sharply with the still popular representation of clouds as homogeneous plane-parallel slabs for the purposes of radiative transfer computations. In typical cloud scenes the opposite asymptotic transport regimes of diffusion and ballistic propagation coexist. We survey the three-dimensional (3D) atmospheric radiative transfer literature over the past 50 years and identify three concurrent and intertwining thrusts: first, how to assess the damage (bias) caused by 3D effects in the operational 1D radiative transfer models? Second, how to mitigate this damage? Finally, can we exploit 3D radiative transfer phenomena to innovate observation methods and technologies? We quickly realize that the smallest scale resolved computationally or observationally may be artificial but is nonetheless a key quantity that separates the 3D radiative transfer solutions into two broad and complementary classes: stochastic and deterministic. Both approaches draw on classic and contemporary statistical, mathematical and computational physics.
NASA Astrophysics Data System (ADS)
Davis, Anthony B.; Marshak, Alexander
2010-02-01
The interplay of sunlight with clouds is a ubiquitous and often pleasant visual experience, but it conjures up major challenges for weather, climate, environmental science and beyond. Those engaged in the characterization of clouds (and the clear air nearby) by remote sensing methods are even more confronted. The problem comes, on the one hand, from the spatial complexity of real clouds and, on the other hand, from the dominance of multiple scattering in the radiation transport. The former ingredient contrasts sharply with the still popular representation of clouds as homogeneous plane-parallel slabs for the purposes of radiative transfer computations. In typical cloud scenes the opposite asymptotic transport regimes of diffusion and ballistic propagation coexist. We survey the three-dimensional (3D) atmospheric radiative transfer literature over the past 50 years and identify three concurrent and intertwining thrusts: first, how to assess the damage (bias) caused by 3D effects in the operational 1D radiative transfer models? Second, how to mitigate this damage? Finally, can we exploit 3D radiative transfer phenomena to innovate observation methods and technologies? We quickly realize that the smallest scale resolved computationally or observationally may be artificial but is nonetheless a key quantity that separates the 3D radiative transfer solutions into two broad and complementary classes: stochastic and deterministic. Both approaches draw on classic and contemporary statistical, mathematical and computational physics.
Automatic Texture Mapping of Architectural and Archaeological 3d Models
NASA Astrophysics Data System (ADS)
Kersten, T. P.; Stallmann, D.
2012-07-01
Today, detailed, complete and exact 3D models with photo-realistic textures are increasingly demanded for numerous applications in architecture and archaeology. Manual texture mapping of 3D models by digital photographs with software packages, such as Maxon Cinema 4D, Autodesk 3Ds Max or Maya, still requires a complex and time-consuming workflow. So, procedures for automatic texture mapping of 3D models are in demand. In this paper two automatic procedures are presented. The first procedure generates 3D surface models with textures by web services, while the second procedure textures already existing 3D models with the software tmapper. The program tmapper is based on the Multi Layer 3D image (ML3DImage) algorithm and developed in the programming language C++. The studies showing that the visibility analysis using the ML3DImage algorithm is not sufficient to obtain acceptable results of automatic texture mapping. To overcome the visibility problem the Point Cloud Painter algorithm in combination with the Z-buffer-procedure will be applied in the future.
Gis-Based Smart Cartography Using 3d Modeling
NASA Astrophysics Data System (ADS)
Malinverni, E. S.; Tassetti, A. N.
2013-08-01
3D City Models have evolved to be important tools for urban decision processes and information systems, especially in planning, simulation, analysis, documentation and heritage management. On the other hand existing and in use numerical cartography is often not suitable to be used in GIS because not geometrically and topologically correctly structured. The research aim is to 3D structure and organize a numeric cartography for GIS and turn it into CityGML standardized features. The work is framed around a first phase of methodological analysis aimed to underline which existing standard (like ISO and OGC rules) can be used to improve the quality requirement of a cartographic structure. Subsequently, from this technical specifics, it has been investigated the translation in formal contents, using an owner interchange software (SketchUp), to support some guide lines implementations to generate a GIS3D structured in GML3. It has been therefore predisposed a test three-dimensional numerical cartography (scale 1:500, generated from range data captured by 3D laser scanner), tested on its quality according to the previous standard and edited when and where necessary. Cad files and shapefiles are converted into a final 3D model (Google SketchUp model) and then exported into a 3D city model (CityGML LoD1/LoD2). The GIS3D structure has been managed in a GIS environment to run further spatial analysis and energy performance estimate, not achievable in a 2D environment. In particular geometrical building parameters (footprint, volume etc.) are computed and building envelop thermal characteristics are derived from. Lastly, a simulation is carried out to deal with asbestos and home renovating charges and show how the built 3D city model can support municipal managers with risk diagnosis of the present situation and development of strategies for a sustainable redevelop.
A new approach towards image based virtual 3D city modeling by using close range photogrammetry
NASA Astrophysics Data System (ADS)
Singh, S. P.; Jain, K.; Mandla, V. R.
2014-05-01
and high resolution satellite images are costly. In this study, proposed method is based on only simple video recording of area. Thus this proposed method is suitable for 3D city modeling. Photo-realistic, scalable, geo-referenced virtual 3D city model is useful for various kinds of applications such as for planning in navigation, tourism, disasters management, transportations, municipality, urban and environmental managements, real-estate industry. Thus this study will provide a good roadmap for geomatics community to create photo-realistic virtual 3D city model by using close range photogrammetry.
Verification and Validation of the k-kL Turbulence Model in FUN3D and CFL3D Codes
NASA Technical Reports Server (NTRS)
Abdol-Hamid, Khaled S.; Carlson, Jan-Renee; Rumsey, Christopher L.
2015-01-01
The implementation of the k-kL turbulence model using multiple computational uid dy- namics (CFD) codes is reported herein. The k-kL model is a two-equation turbulence model based on Abdol-Hamid's closure and Menter's modi cation to Rotta's two-equation model. Rotta shows that a reliable transport equation can be formed from the turbulent length scale L, and the turbulent kinetic energy k. Rotta's equation is well suited for term-by-term mod- eling and displays useful features compared to other two-equation models. An important di erence is that this formulation leads to the inclusion of higher-order velocity derivatives in the source terms of the scale equations. This can enhance the ability of the Reynolds- averaged Navier-Stokes (RANS) solvers to simulate unsteady ows. The present report documents the formulation of the model as implemented in the CFD codes Fun3D and CFL3D. Methodology, veri cation and validation examples are shown. Attached and sepa- rated ow cases are documented and compared with experimental data. The results show generally very good comparisons with canonical and experimental data, as well as matching results code-to-code. The results from this formulation are similar or better than results using the SST turbulence model.
Combined registration of 3D tibia and femur implant models in 3D magnetic resonance images
NASA Astrophysics Data System (ADS)
Englmeier, Karl-Hans; Siebert, Markus; von Eisenhart-Rothe, Ruediger; Graichen, Heiko
2008-03-01
The most frequent reasons for revision of total knee arthroplasty are loosening and abnormal axial alignment leading to an unphysiological kinematic of the knee implant. To get an idea about the postoperative kinematic of the implant, it is essential to determine the position and orientation of the tibial and femoral prosthesis. Therefore we developed a registration method for fitting 3D CAD-models of knee joint prostheses into an 3D MR image. This rigid registration is the basis for a quantitative analysis of the kinematics of knee implants. Firstly the surface data of the prostheses models are converted into a voxel representation; a recursive algorithm determines all boundary voxels of the original triangular surface data. Secondly an initial preconfiguration of the implants by the user is still necessary for the following step: The user has to perform a rough preconfiguration of both remaining prostheses models, so that the fine matching process gets a reasonable starting point. After that an automated gradient-based fine matching process determines the best absolute position and orientation: This iterative process changes all 6 parameters (3 rotational- and 3 translational parameters) of a model by a minimal amount until a maximum value of the matching function is reached. To examine the spread of the final solutions of the registration, the interobserver variability was measured in a group of testers. This variability, calculated by the relative standard deviation, improved from about 50% (pure manual registration) to 0.5% (rough manual preconfiguration and subsequent fine registration with the automatic fine matching process).
Towards a 3D Space Radiation Transport Code
NASA Technical Reports Server (NTRS)
Wilson, J. W.; Tripathl, R. K.; Cicomptta, F. A.; Heinbockel, J. H.; Tweed, J.
2002-01-01
High-speed computational procedures for space radiation shielding have relied on asymptotic expansions in terms of the off-axis scatter and replacement of the general geometry problem by a collection of flat plates. This type of solution was derived for application to human rated systems in which the radius of the shielded volume is large compared to the off-axis diffusion limiting leakage at lateral boundaries. Over the decades these computational codes are relatively complete and lateral diffusion effects are now being added. The analysis for developing a practical full 3D space shielding code is presented.
3D Bioprinting of Tissue/Organ Models.
Pati, Falguni; Gantelius, Jesper; Svahn, Helene Andersson
2016-04-01
In vitro tissue/organ models are useful platforms that can facilitate systematic, repetitive, and quantitative investigations of drugs/chemicals. The primary objective when developing tissue/organ models is to reproduce physiologically relevant functions that typically require complex culture systems. Bioprinting offers exciting prospects for constructing 3D tissue/organ models, as it enables the reproducible, automated production of complex living tissues. Bioprinted tissues/organs may prove useful for screening novel compounds or predicting toxicity, as the spatial and chemical complexity inherent to native tissues/organs can be recreated. In this Review, we highlight the importance of developing 3D in vitro tissue/organ models by 3D bioprinting techniques, characterization of these models for evaluating their resemblance to native tissue, and their application in the prioritization of lead candidates, toxicity testing, and as disease/tumor models. PMID:26895542
3D web visualization of huge CityGML models
NASA Astrophysics Data System (ADS)
Prandi, F.; Devigili, F.; Soave, M.; Di Staso, U.; De Amicis, R.
2015-08-01
Nowadays, rapid technological development into acquiring geo-spatial information; joined to the capabilities to process these data in a relative short period of time, allows the generation of detailed 3D textured city models that will become an essential part of the modern city information infrastructure (Spatial Data Infrastructure) and, can be used to integrate various data from different sources for public accessible visualisation and many other applications. One of the main bottlenecks, which at the moment limit the use of these datasets to few experts, is a lack on efficient visualization systems through the web and interoperable frameworks that allow standardising the access to the city models. The work presented in this paper tries to satisfy these two requirements developing a 3D web-based visualization system based on OGC standards and effective visualization concepts. The architectural framework, based on Services Oriented Architecture (SOA) concepts, provides the 3D city data to a web client designed to support the view process in a very effective way. The first part of the work is to design a framework compliant to the 3D Portrayal Service drafted by the of the Open Geospatial Consortium (OGC) 3D standardization working group. The latter is related to the development of an effective web client able to render in an efficient way the 3D city models.
3-D electromagnetic modeling of wakefields in accelerator components
Poole, B.R.; Caporaso, G.J.; Ng, Wang C.; Shang, C.C.; Steich, D.
1996-09-18
We discuss the use of 3-D finite-difference time-domain (FDTD) electromagnetic codes for modeling accelerator components. Computational modeling of cylindrically symmetric structures such as induction accelerator cells has been very successful in predicting the wake potential and wake impedances of these structures, but full 3-D modeling of complex structures has been limited due to substantial computer resources required for a full 3-D model. New massively parallel 3-D time domain electromagnetic codes now under development using conforming unstructured meshes allow a substantial increase in the geometric fidelity of the structures being modeled. Development of these new codes are discussed in context of applicability to accelerator problems. Various 3-D structures are tested with an existing cubical cell FDTD code and wake impedances compared with simple analytic models for the structures; results will be used as benchmarks for testing the new time time domain codes. Structures under consideration include a stripline beam position monitor as well as circular and elliptical apertures in circular waveguides. Excellent agreement for monopole and dipole impedances with models were found for these structures below the cutoff frequency of the beam line.
3-D electromagnetic modeling of wakefields in accelerator components
Poole, Brian R.; Caporaso, George J.; Ng, Wang C.; Shang, Clifford C.; Steich, David
1997-02-01
We discuss the use of 3-D finite-difference time-domain (FDTD) electromagnetic codes for the modeling of accelerator components. Computational modeling of cylindrically symmetric structures such as induction accelerator cells has been extremely successful in predicting the wake potential and wake impedances of these structures, but fully 3-D modeling of complex structures has been limited due to the substantial computer resources required for a fully 3-D model. New massively parallel 3-D time domain electromagnetic codes now under development using conforming unstructured meshes allow a substantial increase in the geometric fidelity of the structures being modeled. Development of these new codes will be discussed in the context of their applicability to accelerator problems. A variety of 3-D structures are tested with an existing cubical cell FDTD code and the wake impedances are compared with simple analytic models for the structures. These results will provide a set of benchmarks for testing the new time domain codes. Structures under consideration include a stripline beam position monitor as well as circular and elliptical apertures in circular waveguides. Excellent agreement for the monopole and dipole impedances with the models are found for these structures below the cutoff frequency of the beam line.
Multivariate 3D modelling of Scottish soil properties
NASA Astrophysics Data System (ADS)
Poggio, Laura; Gimona, Alessandro
2015-04-01
Information regarding soil properties across landscapes at national or continental scales is critical for better soil and environmental management and for climate regulation and adaptation policy. The prediction of soil properties variation in space and time and their uncertainty is an important part of environmental modelling. Soil properties, and in particular the 3 fractions of soil texture, exhibit strong co-variation among themselves and therefore taking into account this correlation leads to spatially more accurate results. In this study the continuous vertical and lateral distributions of relevant soil properties in Scottish soils were modelled with a multivariate 3D-GAM+GS approach. The approach used involves 1) modelling the multivariate trend with full 3D spatial correlation, i.e., exploiting the values of the neighbouring pixels in 3D-space, and 2) 3D kriging to interpolate the residuals. The values at each cell for each of the considered depth layers were defined using a hybrid GAM-geostatistical 3D model, combining the fitting of a GAM (generalised Additive Models) to estimate multivariate trend of the variables, using a 3D smoother with related covariates. Gaussian simulations of the model residuals were used as spatial component to account for local details. A dataset of about 26,000 horizons (7,800 profiles) was used for this study. A validation set was randomly selected as 25% of the full dataset. Numerous covariates derived from globally available data, such as MODIS and SRTM, are considered. The results of the 3D-GAM+kriging showed low RMSE values, good R squared and an accurate reproduction of the spatial structure of the data for a range of soil properties. The results have an out-of-sample RMSE between 10 to 15% of the observed range when taking into account the whole profile. The approach followed allows the assessment of the uncertainty of both the trend and the residuals.
Perception-based shape retrieval for 3D building models
NASA Astrophysics Data System (ADS)
Zhang, Man; Zhang, Liqiang; Takis Mathiopoulos, P.; Ding, Yusi; Wang, Hao
2013-01-01
With the help of 3D search engines, a large number of 3D building models can be retrieved freely online. A serious disadvantage of most rotation-insensitive shape descriptors is their inability to distinguish between two 3D building models which are different at their main axes, but appear similar when one of them is rotated. To resolve this problem, we present a novel upright-based normalization method which not only correctly rotates such building models, but also greatly simplifies and accelerates the abstraction and the matching of building models' shape descriptors. Moreover, the abundance of architectural styles significantly hinders the effective shape retrieval of building models. Our research has shown that buildings with different designs are not well distinguished by the widely recognized shape descriptors for general 3D models. Motivated by this observation and to further improve the shape retrieval quality, a new building matching method is introduced and analyzed based on concepts found in the field of perception theory and the well-known Light Field descriptor. The resulting normalized building models are first classified using the qualitative shape descriptors of Shell and Unevenness which outline integral geometrical and topological information. These models are then put in on orderly fashion with the help of an improved quantitative shape descriptor which we will term as Horizontal Light Field Descriptor, since it assembles detailed shape characteristics. To accurately evaluate the proposed methodology, an enlarged building shape database which extends previous well-known shape benchmarks was implemented as well as a model retrieval system supporting inputs from 2D sketches and 3D models. Various experimental performance evaluation results have shown that, as compared to previous methods, retrievals employing the proposed matching methodology are faster and more consistent with human recognition of spatial objects. In addition these performance
Microfluidic 3D cell culture: from tools to tissue models.
van Duinen, Vincent; Trietsch, Sebastiaan J; Joore, Jos; Vulto, Paul; Hankemeier, Thomas
2015-12-01
The transition from 2D to 3D cell culture techniques is an important step in a trend towards better biomimetic tissue models. Microfluidics allows spatial control over fluids in micrometer-sized channels has become a valuable tool to further increase the physiological relevance of 3D cell culture by enabling spatially controlled co-cultures, perfusion flow and spatial control over of signaling gradients. This paper reviews most important developments in microfluidic 3D culture since 2012. Most efforts were exerted in the field of vasculature, both as a tissue on its own and as part of cancer models. We observe that the focus is shifting from tool building to implementation of specific tissue models. The next big challenge for the field is the full validation of these models and subsequently the implementation of these models in drug development pipelines of the pharmaceutical industry and ultimately in personalized medicine applications. PMID:26094109
Evaluating Biomaterial- and Microfluidic-Based 3D Tumor Models.
Carvalho, Mariana R; Lima, Daniela; Reis, Rui L; Correlo, Vitor M; Oliveira, Joaquim M
2015-11-01
Cancer is a major cause of morbidity and mortality worldwide, with a disease burden estimated to increase over the coming decades. Disease heterogeneity and limited information on cancer biology and disease mechanisms are aspects that 2D cell cultures fail to address. Here, we review the current ‘state-of-the-art’ in 3D tissue-engineering (TE) models developed for, and used in, cancer research. We assess the potential for scaffold-based TE models and microfluidics to fill the gap between 2D models and clinical application. We also discuss recent advances in combining the principles of 3D TE models and microfluidics, with a special focus on biomaterials and the most promising chip-based 3D models. PMID:26603572
Eck, Simon; Wörz, Stefan; Müller-Ott, Katharina; Hahn, Matthias; Biesdorf, Andreas; Schotta, Gunnar; Rippe, Karsten; Rohr, Karl
2016-08-01
The genome is partitioned into regions of euchromatin and heterochromatin. The organization of heterochromatin is important for the regulation of cellular processes such as chromosome segregation and gene silencing, and their misregulation is linked to cancer and other diseases. We present a model-based approach for automatic 3D segmentation and 3D shape analysis of heterochromatin foci from 3D confocal light microscopy images. Our approach employs a novel 3D intensity model based on spherical harmonics, which analytically describes the shape and intensities of the foci. The model parameters are determined by fitting the model to the image intensities using least-squares minimization. To characterize the 3D shape of the foci, we exploit the computed spherical harmonics coefficients and determine a shape descriptor. We applied our approach to 3D synthetic image data as well as real 3D static and real 3D time-lapse microscopy images, and compared the performance with that of previous approaches. It turned out that our approach yields accurate 3D segmentation results and performs better than previous approaches. We also show that our approach can be used for quantifying 3D shape differences of heterochromatin foci. PMID:27037463
NASA Astrophysics Data System (ADS)
Uznir, U.; Anton, F.; Suhaibah, A.; Rahman, A. A.; Mioc, D.
2013-09-01
The advantages of three dimensional (3D) city models can be seen in various applications including photogrammetry, urban and regional planning, computer games, etc.. They expand the visualization and analysis capabilities of Geographic Information Systems on cities, and they can be developed using web standards. However, these 3D city models consume much more storage compared to two dimensional (2D) spatial data. They involve extra geometrical and topological information together with semantic data. Without a proper spatial data clustering method and its corresponding spatial data access method, retrieving portions of and especially searching these 3D city models, will not be done optimally. Even though current developments are based on an open data model allotted by the Open Geospatial Consortium (OGC) called CityGML, its XML-based structure makes it challenging to cluster the 3D urban objects. In this research, we propose an opponent data constellation technique of space-filling curves (3D Hilbert curves) for 3D city model data representation. Unlike previous methods, that try to project 3D or n-dimensional data down to 2D or 3D using Principal Component Analysis (PCA) or Hilbert mappings, in this research, we extend the Hilbert space-filling curve to one higher dimension for 3D city model data implementations. The query performance was tested using a CityGML dataset of 1,000 building blocks and the results are presented in this paper. The advantages of implementing space-filling curves in 3D city modeling will improve data retrieval time by means of optimized 3D adjacency, nearest neighbor information and 3D indexing. The Hilbert mapping, which maps a subinterval of the [0, 1] interval to the corresponding portion of the d-dimensional Hilbert's curve, preserves the Lebesgue measure and is Lipschitz continuous. Depending on the applications, several alternatives are possible in order to cluster spatial data together in the third dimension compared to its
STELLOPT Modeling of the 3D Diagnostic Response in ITER
Lazerson, Samuel A
2013-05-07
The ITER three dimensional diagnostic response to an n=3 resonant magnetic perturbation is modeled using the STELLOPT code. The in-vessel coils apply a resonant magnetic perturbation (RMP) fi eld which generates a 4 cm edge displacement from axisymmetry as modeled by the VMEC 3D equilibrium code. Forward modeling of flux loop and magnetic probe response with the DIAGNO code indicates up to 20 % changes in measured plasma signals. Simulated LIDAR measurements of electron temperature indicate 2 cm shifts on the low field side of the plasma. This suggests that the ITER diagnostic will be able to diagnose the 3D structure of the equilibria.
MR image denoising method for brain surface 3D modeling
NASA Astrophysics Data System (ADS)
Zhao, De-xin; Liu, Peng-jie; Zhang, De-gan
2014-11-01
Three-dimensional (3D) modeling of medical images is a critical part of surgical simulation. In this paper, we focus on the magnetic resonance (MR) images denoising for brain modeling reconstruction, and exploit a practical solution. We attempt to remove the noise existing in the MR imaging signal and preserve the image characteristics. A wavelet-based adaptive curve shrinkage function is presented in spherical coordinates system. The comparative experiments show that the denoising method can preserve better image details and enhance the coefficients of contours. Using these denoised images, the brain 3D visualization is given through surface triangle mesh model, which demonstrates the effectiveness of the proposed method.
Potential of 3D City Models to assess flood vulnerability
NASA Astrophysics Data System (ADS)
Schröter, Kai; Bochow, Mathias; Schüttig, Martin; Nagel, Claus; Ross, Lutz; Kreibich, Heidi
2016-04-01
Vulnerability, as the product of exposure and susceptibility, is a key factor of the flood risk equation. Furthermore, the estimation of flood loss is very sensitive to the choice of the vulnerability model. Still, in contrast to elaborate hazard simulations, vulnerability is often considered in a simplified manner concerning the spatial resolution and geo-location of exposed objects as well as the susceptibility of these objects at risk. Usually, area specific potential flood loss is quantified on the level of aggregated land-use classes, and both hazard intensity and resistance characteristics of affected objects are represented in highly simplified terms. We investigate the potential of 3D City Models and spatial features derived from remote sensing data to improve the differentiation of vulnerability in flood risk assessment. 3D City Models are based on CityGML, an application scheme of the Geography Markup Language (GML), which represents the 3D geometry, 3D topology, semantics and appearance of objects on different levels of detail. As such, 3D City Models offer detailed spatial information which is useful to describe the exposure and to characterize the susceptibility of residential buildings at risk. This information is further consolidated with spatial features of the building stock derived from remote sensing data. Using this database a spatially detailed flood vulnerability model is developed by means of data-mining. Empirical flood damage data are used to derive and to validate flood susceptibility models for individual objects. We present first results from a prototype application in the city of Dresden, Germany. The vulnerability modeling based on 3D City Models and remote sensing data is compared i) to the generally accepted good engineering practice based on area specific loss potential and ii) to a highly detailed representation of flood vulnerability based on a building typology using urban structure types. Comparisons are drawn in terms of
3D MHD Models of Active Region Loops
NASA Technical Reports Server (NTRS)
Ofman, Leon
2004-01-01
Present imaging and spectroscopic observations of active region loops allow to determine many physical parameters of the coronal loops, such as the density, temperature, velocity of flows in loops, and the magnetic field. However, due to projection effects many of these parameters remain ambiguous. Three dimensional imaging in EUV by the STEREO spacecraft will help to resolve the projection ambiguities, and the observations could be used to setup 3D MHD models of active region loops to study the dynamics and stability of active regions. Here the results of 3D MHD models of active region loops are presented, and the progress towards more realistic 3D MHD models of active regions. In particular the effects of impulsive events on the excitation of active region loop oscillations, and the generation, propagations and reflection of EIT waves are shown. It is shown how 3D MHD models together with 3D EUV observations can be used as a diagnostic tool for active region loop physical parameters, and to advance the science of the sources of solar coronal activity.
3D head model classification using optimized EGI
NASA Astrophysics Data System (ADS)
Tong, Xin; Wong, Hau-san; Ma, Bo
2006-02-01
With the general availability of 3D digitizers and scanners, 3D graphical models have been used widely in a variety of applications. This has led to the development of search engines for 3D models. Especially, 3D head model classification and retrieval have received more and more attention in view of their many potential applications in criminal identifications, computer animation, movie industry and medical industry. This paper addresses the 3D head model classification problem using 2D subspace analysis methods such as 2D principal component analysis (2D PCA[3]) and 2D fisher discriminant analysis (2DLDA[5]). It takes advantage of the fact that the histogram is a 2D image, and we can extract the most useful information from these 2D images to get a good result accordingingly. As a result, there are two main advantages: First, we can perform less calculation to obtain the same rate of classification; second, we can reduce the dimensionality more than PCA to obtain a higher efficiency.
Vhrs Stereo Images for 3d Modelling of Buildings
NASA Astrophysics Data System (ADS)
Bujakiewicz, A.; Holc, M.
2012-07-01
The paper presents the project which was carried out in the Photogrammetric Laboratory of Warsaw University of Technology. The experiment is concerned with the extraction of 3D vector data for buildings creation from 3D photogrammetric model based on the Ikonos stereo images. The model was reconstructed with photogrammetric workstation - Summit Evolution combined with ArcGIS 3D platform. Accuracy of 3D model was significantly improved by use for orientation of pair of satellite images the stereo measured tie points distributed uniformly around the model area in addition to 5 control points. The RMS for model reconstructed on base of the RPC coefficients only were 16,6 m, 2,7 m and 47,4 m, for X, Y and Z coordinates, respectively. By addition of 5 control points the RMS were improved to 0,7 m, 0,7 m 1,0 m, where the best results were achieved when RMS were estimated from deviations in 17 check points (with 5 control points)and amounted to 0,4 m, 0,5 m and 0,6 m, for X, Y, and Z respectively. The extracted 3D vector data for buildings were integrated with 2D data of the ground footprints and afterwards they were used for 3D modelling of buildings in Google SketchUp software. The final results were compared with the reference data obtained from other sources. It was found that the shape of buildings (in concern to the number of details) had been reconstructed on level of LoD1, when the accuracy of these models corresponded to the level of LoD2.
3D model of amphioxus steroid receptor complexed with estradiol
Baker, Michael E.; Chang, David J.
2009-08-28
The origins of signaling by vertebrate steroids are not fully understood. An important advance was the report that an estrogen-binding steroid receptor [SR] is present in amphioxus, a basal chordate with a similar body plan as vertebrates. To investigate the evolution of estrogen-binding to steroid receptors, we constructed a 3D model of amphioxus SR complexed with estradiol. This 3D model indicates that although the SR is activated by estradiol, some interactions between estradiol and human ER{alpha} are not conserved in the SR, which can explain the low affinity of estradiol for the SR. These differences between the SR and ER{alpha} in the steroid-binding domain are sufficient to suggest that another steroid is the physiological regulator of the SR. The 3D model predicts that mutation of Glu-346 to Gln will increase the affinity of testosterone for amphioxus SR and elucidate the evolution of steroid-binding to nuclear receptors.
Quality of 3D Models Generated by SFM Technology
NASA Astrophysics Data System (ADS)
Marčiš, Marián
2013-12-01
Using various types of automation in digital photogrammetry is associated with questions such as the accuracy of a 3D model generated on various types of surfaces and textures, the financial costs of the equipment needed, and also the time costs of the processing. This topic deals with the actual technology of computer vision, which allows the automated exterior orientation of images, camera calibration, and the generation of 3D models directly from images of the object itself, based on the automatic detection of significant points. Detailed testing is done using the Agisoft PhotoScan system, and the camera configuration is solved with respect to the accuracy of the 3D model generated and the time consumption of the calculations for the different types of textures and the different settings for the processing.
3D surface digitizing and modeling development at ITRI
NASA Astrophysics Data System (ADS)
Hsueh, Wen-Jean
2000-06-01
This paper gives an overview of the research and development activities in 3D surface digitizing and modeling conducted at the Industrial Technology Research Institute (ITRI) of Taiwan in the past decade. As a major technology and consulting service provider of the area, ITRI has developed 3D laser scanning digitizers ranging from low-cost compacts, industrial CAD/CAM digitizing, to large human body scanner, with in-house 3D surface modeling software to provide total solution in reverse engineering that requires processing capabilities of large number of 3D data. Based on both hardware and software technologies in scanning, merging, registration, surface fitting, reconstruction, and compression, ITRI is now exploring innovative methodologies that provide higher performances, including hardware-based correlation algorithms with advanced camera designs, animation surface model reconstruction, and optical tracking for motion capture. It is expected that the need for easy and fast high-quality 3D information in the near future will grow exponentially, at the same amazing rate as the internet and the human desire for realistic and natural images.
Modelling Gaia CCD pixels with Silvaco 3D engineering software
NASA Astrophysics Data System (ADS)
Seabroke, G. M.; Prod'Homme, T.; Hopkinson, G.; Burt, D.; Robbins, M.; Holland, A.
2011-02-01
Gaia will only achieve its unprecedented measurement accuracy requirements with detailed calibration and correction for radiation damage. We present our Silvaco 3D engineering software model of the Gaia CCD pixel and two of its applications for Gaia: (1) physically interpreting supplementary buried channel (SBC) capacity measurements (pocket-pumping and first pixel response) in terms of e2v manufacturing doping alignment tolerances; and (2) deriving electron densities within a charge packet as a function of the number of constituent electrons and 3D position within the charge packet as input to microscopic models being developed to simulate radiation damage.
Parallel Optimization of 3D Cardiac Electrophysiological Model Using GPU
Xia, Yong; Wang, Kuanquan; Zhang, Henggui
2015-01-01
Large-scale 3D virtual heart model simulations are highly demanding in computational resources. This imposes a big challenge to the traditional computation resources based on CPU environment, which already cannot meet the requirement of the whole computation demands or are not easily available due to expensive costs. GPU as a parallel computing environment therefore provides an alternative to solve the large-scale computational problems of whole heart modeling. In this study, using a 3D sheep atrial model as a test bed, we developed a GPU-based simulation algorithm to simulate the conduction of electrical excitation waves in the 3D atria. In the GPU algorithm, a multicellular tissue model was split into two components: one is the single cell model (ordinary differential equation) and the other is the diffusion term of the monodomain model (partial differential equation). Such a decoupling enabled realization of the GPU parallel algorithm. Furthermore, several optimization strategies were proposed based on the features of the virtual heart model, which enabled a 200-fold speedup as compared to a CPU implementation. In conclusion, an optimized GPU algorithm has been developed that provides an economic and powerful platform for 3D whole heart simulations. PMID:26581957
Geospatial Modelling Approach for 3d Urban Densification Developments
NASA Astrophysics Data System (ADS)
Koziatek, O.; Dragićević, S.; Li, S.
2016-06-01
With growing populations, economic pressures, and the need for sustainable practices, many urban regions are rapidly densifying developments in the vertical built dimension with mid- and high-rise buildings. The location of these buildings can be projected based on key factors that are attractive to urban planners, developers, and potential buyers. Current research in this area includes various modelling approaches, such as cellular automata and agent-based modelling, but the results are mostly linked to raster grids as the smallest spatial units that operate in two spatial dimensions. Therefore, the objective of this research is to develop a geospatial model that operates on irregular spatial tessellations to model mid- and high-rise buildings in three spatial dimensions (3D). The proposed model is based on the integration of GIS, fuzzy multi-criteria evaluation (MCE), and 3D GIS-based procedural modelling. Part of the City of Surrey, within the Metro Vancouver Region, Canada, has been used to present the simulations of the generated 3D building objects. The proposed 3D modelling approach was developed using ESRI's CityEngine software and the Computer Generated Architecture (CGA) language.
3-D model of beam kicker in DARHT-2 accelerator
NASA Astrophysics Data System (ADS)
Thoma, Carsten; Genoni, Thomas; Hughes, Thomas
2003-10-01
The DARHT-2 beamline uses a fast stripline kicker developed at LLNL [1] to create a series of short pulses out of a 2 microsecond pulse for use in high resolution x-ray radiography. Normally, a static bias dipole bends the 2 kA, 18 MeV electron beam off axis into a dump. When the fast stripline kicker is activated, the static dipole kick is cancelled by the dynamic dipole field of the kicker, and the beam travels to the x-ray converter. 3-D PIC simulations are performed to compute the effect of the kicker on the beam. The calculations incorporate the kicker biplate conductor geometry, allowing for accurate modeling of the effects of higher multipole fields as well as beam wakefield effects. Beam emittance growth through the kicker is investigated for various beam loads. [1] B.R. Poole and Y.-J. Chen, "Particle Simulations of DARHT-2 Transport System", Proc. PAC 2001 Conference (http://accelconf.web.cern.ch/AccelConf/p01/PAPERS/RPPH034.PDF).
Robust model-based 3d/3D fusion using sparse matching for minimally invasive surgery.
Neumann, Dominik; Grbic, Sasa; John, Matthias; Navab, Nassir; Hornegger, Joachim; Ionasec, Razvan
2013-01-01
Classical surgery is being disrupted by minimally invasive and transcatheter procedures. As there is no direct view or access to the affected anatomy, advanced imaging techniques such as 3D C-arm CT and C-arm fluoroscopy are routinely used for intra-operative guidance. However, intra-operative modalities have limited image quality of the soft tissue and a reliable assessment of the cardiac anatomy can only be made by injecting contrast agent, which is harmful to the patient and requires complex acquisition protocols. We propose a novel sparse matching approach for fusing high quality pre-operative CT and non-contrasted, non-gated intra-operative C-arm CT by utilizing robust machine learning and numerical optimization techniques. Thus, high-quality patient-specific models can be extracted from the pre-operative CT and mapped to the intra-operative imaging environment to guide minimally invasive procedures. Extensive quantitative experiments demonstrate that our model-based fusion approach has an average execution time of 2.9 s, while the accuracy lies within expert user confidence intervals. PMID:24505663
3D Model Generation From the Engineering Drawing
NASA Astrophysics Data System (ADS)
Vaský, Jozef; Eliáš, Michal; Bezák, Pavol; Červeňanská, Zuzana; Izakovič, Ladislav
2010-01-01
The contribution deals with the transformation of engineering drawings in a paper form into a 3D computer representation. A 3D computer model can be further processed in CAD/CAM system, it can be modified, archived, and a technical drawing can be then generated from it as well. The transformation process from paper form to the data one is a complex and difficult one, particularly owing to the different types of drawings, forms of displayed objects and encountered errors and deviations from technical standards. The algorithm for 3D model generating from an orthogonal vector input representing a simplified technical drawing of the rotational part is described in this contribution. The algorithm was experimentally implemented as ObjectARX application in the AutoCAD system and the test sample as the representation of the rotational part was used for verificaton.
3D shape decomposition and comparison for gallbladder modeling
NASA Astrophysics Data System (ADS)
Huang, Weimin; Zhou, Jiayin; Liu, Jiang; Zhang, Jing; Yang, Tao; Su, Yi; Law, Gim Han; Chui, Chee Kong; Chang, Stephen
2011-03-01
This paper presents an approach to gallbladder shape comparison by using 3D shape modeling and decomposition. The gallbladder models can be used for shape anomaly analysis and model comparison and selection in image guided robotic surgical training, especially for laparoscopic cholecystectomy simulation. The 3D shape of a gallbladder is first represented as a surface model, reconstructed from the contours segmented in CT data by a scheme of propagation based voxel learning and classification. To better extract the shape feature, the surface mesh is further down-sampled by a decimation filter and smoothed by a Taubin algorithm, followed by applying an advancing front algorithm to further enhance the regularity of the mesh. Multi-scale curvatures are then computed on the regularized mesh for the robust saliency landmark localization on the surface. The shape decomposition is proposed based on the saliency landmarks and the concavity, measured by the distance from the surface point to the convex hull. With a given tolerance the 3D shape can be decomposed and represented as 3D ellipsoids, which reveal the shape topology and anomaly of a gallbladder. The features based on the decomposed shape model are proposed for gallbladder shape comparison, which can be used for new model selection. We have collected 19 sets of abdominal CT scan data with gallbladders, some shown in normal shape and some in abnormal shapes. The experiments have shown that the decomposed shapes reveal important topology features.
Geodiversity: Exploration of 3D geological model space
NASA Astrophysics Data System (ADS)
Lindsay, M. D.; Jessell, M. W.; Ailleres, L.; Perrouty, S.; de Kemp, E.; Betts, P. G.
2013-05-01
The process of building a 3D model necessitates the reconciliation of field observations, geophysical interpretation, geological data uncertainty and the prevailing tectonic evolution hypotheses and interpretations. Uncertainty is compounded when clustered data points collected at local scales are statistically upscaled to one or two points for use in regional models. Interpretation is required to interpolate between sparse field data points using ambiguous geophysical data in covered terranes. It becomes clear that multiple interpretations are possible during model construction. The various interpretations are considered as potential natural representatives, but pragmatism typically dictates that just a single interpretation is offered by the modelling process. Uncertainties are introduced into the 3D model during construction from a variety of sources and through data set optimisation that produces a single model. Practices such as these are likely to result in a model that does not adequately represent the target geology. A set of geometrical ‘geodiversity’ metrics are used to analyse a 3D model of the Gippsland Basin, southeastern Australia after perturbing geological input data via uncertainty simulation. The resulting sets of perturbed geological observations are used to calculate a suite of geological 3D models that display a range of geological architectures. The concept of biodiversity has been adapted for the geosciences to quantify geometric variability, or geodiversity, between models in order to understand the effect uncertainty has models geometry. Various geometrical relationships (depth, volume, contact surface area, curvature and geological complexity) are used to describe the range of possibilities exhibited throughout the model suite. End-member models geodiversity metrics are classified in a similar manner to taxonomic descriptions. Further analysis of the model suite is performed using principal component analysis (PCA) to determine
3D unstructured-mesh radiation transport codes
Morel, J.
1997-12-31
Three unstructured-mesh radiation transport codes are currently being developed at Los Alamos National Laboratory. The first code is ATTILA, which uses an unstructured tetrahedral mesh in conjunction with standard Sn (discrete-ordinates) angular discretization, standard multigroup energy discretization, and linear-discontinuous spatial differencing. ATTILA solves the standard first-order form of the transport equation using source iteration in conjunction with diffusion-synthetic acceleration of the within-group source iterations. DANTE is designed to run primarily on workstations. The second code is DANTE, which uses a hybrid finite-element mesh consisting of arbitrary combinations of hexahedra, wedges, pyramids, and tetrahedra. DANTE solves several second-order self-adjoint forms of the transport equation including the even-parity equation, the odd-parity equation, and a new equation called the self-adjoint angular flux equation. DANTE also offers three angular discretization options: $S{_}n$ (discrete-ordinates), $P{_}n$ (spherical harmonics), and $SP{_}n$ (simplified spherical harmonics). DANTE is designed to run primarily on massively parallel message-passing machines, such as the ASCI-Blue machines at LANL and LLNL. The third code is PERICLES, which uses the same hybrid finite-element mesh as DANTE, but solves the standard first-order form of the transport equation rather than a second-order self-adjoint form. DANTE uses a standard $S{_}n$ discretization in angle in conjunction with trilinear-discontinuous spatial differencing, and diffusion-synthetic acceleration of the within-group source iterations. PERICLES was initially designed to run on workstations, but a version for massively parallel message-passing machines will be built. The three codes will be described in detail and computational results will be presented.
NASA Astrophysics Data System (ADS)
Sharkawi, K.-H.; Abdul-Rahman, A.
2013-09-01
Cities and urban areas entities such as building structures are becoming more complex as the modern human civilizations continue to evolve. The ability to plan and manage every territory especially the urban areas is very important to every government in the world. Planning and managing cities and urban areas based on printed maps and 2D data are getting insufficient and inefficient to cope with the complexity of the new developments in big cities. The emergence of 3D city models have boosted the efficiency in analysing and managing urban areas as the 3D data are proven to represent the real world object more accurately. It has since been adopted as the new trend in buildings and urban management and planning applications. Nowadays, many countries around the world have been generating virtual 3D representation of their major cities. The growing interest in improving the usability of 3D city models has resulted in the development of various tools for analysis based on the 3D city models. Today, 3D city models are generated for various purposes such as for tourism, location-based services, disaster management and urban planning. Meanwhile, modelling 3D objects are getting easier with the emergence of the user-friendly tools for 3D modelling available in the market. Generating 3D buildings with high accuracy also has become easier with the availability of airborne Lidar and terrestrial laser scanning equipments. The availability and accessibility to this technology makes it more sensible to analyse buildings in urban areas using 3D data as it accurately represent the real world objects. The Open Geospatial Consortium (OGC) has accepted CityGML specifications as one of the international standards for representing and exchanging spatial data, making it easier to visualize, store and manage 3D city models data efficiently. CityGML able to represents the semantics, geometry, topology and appearance of 3D city models in five well-defined Level-of-Details (LoD), namely LoD0
Creating Physical 3D Stereolithograph Models of Brain and Skull
Kelley, Daniel J.; Farhoud, Mohammed; Meyerand, M. Elizabeth; Nelson, David L.; Ramirez, Lincoln F.; Dempsey, Robert J.; Wolf, Alan J.; Alexander, Andrew L.; Davidson, Richard J.
2007-01-01
The human brain and skull are three dimensional (3D) anatomical structures with complex surfaces. However, medical images are often two dimensional (2D) and provide incomplete visualization of structural morphology. To overcome this loss in dimension, we developed and validated a freely available, semi-automated pathway to build 3D virtual reality (VR) and hand-held, stereolithograph models. To evaluate whether surface visualization in 3D was more informative than in 2D, undergraduate students (n = 50) used the Gillespie scale to rate 3D VR and physical models of both a living patient-volunteer's brain and the skull of Phineas Gage, a historically famous railroad worker whose misfortune with a projectile tamping iron provided the first evidence of a structure-function relationship in brain. Using our processing pathway, we successfully fabricated human brain and skull replicas and validated that the stereolithograph model preserved the scale of the VR model. Based on the Gillespie ratings, students indicated that the biological utility and quality of visual information at the surface of VR and stereolithograph models were greater than the 2D images from which they were derived. The method we developed is useful to create VR and stereolithograph 3D models from medical images and can be used to model hard or soft tissue in living or preserved specimens. Compared to 2D images, VR and stereolithograph models provide an extra dimension that enhances both the quality of visual information and utility of surface visualization in neuroscience and medicine. PMID:17971879
Teaching the geological subsurface with 3D models
NASA Astrophysics Data System (ADS)
Thorpe, Steve; Ward, Emma
2014-05-01
3D geological models have great potential as a resource when teaching geological concepts as it allows the student to visualise and interrogate UK geology. They are especially useful when dealing with the conversion of 2D field, map and GIS outputs into three dimensional geological units, which is a common problem for many students. Today's earth science students use a variety of skills and processes during their learning experience including spatial thinking, image construction, detecting patterns, making predictions and deducing the orientation of themselves. 3D geological models can reinforce spatial thinking strategies and encourage students to think about processes and properties, in turn helping the student to recognise pre-learnt geological principles in the field and to convert what they see at the surface into a picture of what is going on at depth. The British Geological Survey (BGS) has been producing digital 3D geological models for over 10 years. The models produced are revolutionising the working practices, data standards and products of the BGS. Sharing our geoscience information with academia is highlighted throughout the BGS strategy as is instilling practical skills in future geoscience professionals, such as model building and interpretation. In 2009 a project was launched to investigate the potential of the models as a teaching resource. The study included justifying if and how the models help students to learn, how models have been used historically, and how other forms of modelling are being used today. BGS now produce 3D geological models for use by anyone teaching or learning geoscience. They incorporate educational strategies that will develop geospatial skills and alleviate potential problems that some students experience. They are contained within contemporary case studies and show standard geological concepts, structures, sedimentary rocks, cross sections and field techniques. 3D geological models of the Isle of Wight and Ingleborough
A killer micro attack on 3D neutron transport
Dorr, M.R.; Ferguson, J.M.
1990-11-01
We describe the deterministic solution of the neutron transport equation and the computation of the effective criticality of three-dimensional assemblies using the BBN TC2000 killer micros. We observe that the performance of our research code PTRAN running on 48 processors of the TC2000 is competitive with the partially vectorizable version running on a single Cray Y/MP processor. This performance scales well with the number of processors on real problems, including those that are not load balanced a priori. To obtain this performance, we explicitly specify and exploit data locality and data dependence using domain decomposition and dynamic job scheduling. 3 refs., 4 figs., 2 tabs.
Analysis of transport connectivity in karstic aquifers spanned by 3D conduit networks
NASA Astrophysics Data System (ADS)
Ronayne, M. J.
2013-12-01
Karst aquifers are characterized by interconnected conduits that behave as structural pathways for groundwater and solutes. This modeling study assesses the influence of conduit network geometry on solute transport behavior within karst systems. Synthetic karst aquifers containing 3D conduit networks were considered. Networks of varying complexity were generated using a directed percolation model. Flow and transport simulations were conducted for each synthetic aquifer by modeling the conduits as discretized high-permeability features within a uniform matrix material. Transport connectivity and dispersive properties were evaluated using statistical moments of the solute arrival time distribution at the downgradient conduit outlet (karst spring). In addition, a new connectivity metric that quantifies solute residence time within conduits was considered. Results show that a more complex network leads to enhanced mixing between the conduit and matrix domains, which has the effect of reducing transport connectivity. This modeling study illustrates how typically available transport data (e.g., solute breakthrough curves at the conduit outlet) may reveal information about the internal network structure, thus providing guidance for future inverse modeling.
Performance and Cognitive Assessment in 3-D Modeling
ERIC Educational Resources Information Center
Fahrer, Nolan E.; Ernst, Jeremy V.; Branoff, Theodore J.; Clark, Aaron C.
2011-01-01
The purpose of this study was to investigate identifiable differences between performance and cognitive assessment scores in a 3-D modeling unit of an engineering drafting course curriculum. The study aimed to provide further investigation of the need of skill-based assessments in engineering/technical graphics courses to potentially increase…
Tracking people and cars using 3D modeling and CCTV.
Edelman, Gerda; Bijhold, Jurrien
2010-10-10
The aim of this study was to find a method for the reconstruction of movements of people and cars using CCTV footage and a 3D model of the environment. A procedure is proposed, in which video streams are synchronized and displayed in a 3D model, by using virtual cameras. People and cars are represented by cylinders and boxes, which are moved in the 3D model, according to their movements as shown in the video streams. The procedure was developed and tested in an experimental setup with test persons who logged their GPS coordinates as a recording of the ground truth. Results showed that it is possible to implement this procedure and to reconstruct movements of people and cars from video recordings. The procedure was also applied to a forensic case. In this work we experienced that more situational awareness was created by the 3D model, which made it easier to track people on multiple video streams. Based on all experiences from the experimental set up and the case, recommendations are formulated for use in practice. PMID:20439141
A Sketching Interface for Freeform 3D Modeling
NASA Astrophysics Data System (ADS)
Igarashi, Takeo
This chapter introduces Teddy, a sketch-based modeling system to quickly and easily design freeform models such as stuffed animals and other rotund objects. The user draws several 2D freeform strokes interactively on the screen and the system automatically constructs plausible 3D polygonal surfaces. Our system supports several modeling operations, including the operation to construct a 3D polygonal surface from a 2D silhouette drawn by the user: it inflates the region surrounded by the silhouette making a wide area fat, and a narrow area thin. Teddy, our prototype system, is implemented as a Java program, and the mesh construction is done in real-time on a standard PC. Our informal user study showed that a first-time user masters the operations within 10 minutes, and can construct interesting 3D models within minutes. We also report the result of a case study where a high school teacher taught various 3D concepts in geography using the system.
Assessment of 3D Models Used in Contours Studies
ERIC Educational Resources Information Center
Alvarez, F. J. Ayala; Parra, E. B. Blazquez; Tubio, F. Montes
2015-01-01
This paper presents an experimental research focusing on the view of first year students. The aim is to check the quality of implementing 3D models integrated in the curriculum. We search to determine students' preference between the various means facilitated in order to understand the given subject. Students have been respondents to prove the…
3d model for site effect assessment at Nice (France)
NASA Astrophysics Data System (ADS)
Bertrand, E.; Courrioux, G.; Bourgine, B.; Bour, M.; Guillen, A.; Mouroux, P.; Devaux, E.; Duval, A. M.
2003-04-01
Assessment of lithologic site effects is based on an accurate knowledge of properties and geometry of superficial geological formations, i.e. ideally a 3D-4G subsurface model (Geology, Geomorphology, Geophysics, Geotechnics). Such a model has been achieved using a 3D geomodeler ("Geological Editor" developed at BRGM) that allows building 3D volumes of geological formations starting from drill-holes data, sections, and geological maps. This software uses a pseudo-stratigraphic pile in order to reproduce geological history and structural relationships (erosion, deposit). The interpolation is achieved through a 3D potential field. A geostatistical formulation allows to consider data points of a geological limit as equipotential, and sructural dips as gradient inputs for the 3D field interpolation. Then isosurfaces corresponding to each limit are combined using formation relationships to provide volumic models of geological formations. The first task was to identify the relevant geological formations underlying in Nice area. In a first approach Mesozoic bedrock, Pliocene bedrock, and Quaternary alluvial deposits have been distinguished considering their seismic properties. Then alluvions have been subdivided into 9 groups according to their lithology and granulometry. Modelling has been performed considering 2 major erosion surfaces, post-Mesozoic and post-Pliocene. The succession of Quaternary alluviums have been considered as "onlap deposits". Given adjacent lithologies contained in maps and drill holes, these relations lead to logical identification of the roof of formations to be interpolated. The distribution of modeled geological formations can be visualised in 3 dimensions or in 2D sections. Besides the visual interest of 3D representations, the model is first used to build a series of earth columns over a 50m/50m 2D grid. A statistical analysis allowed to identify 73 existing configurations in the Nice district area. Among these, only 15 configurations
A killer micro attack on 3D neutron transport
Dorr, M.R.; Ferguson, J.M.
1990-11-16
In this paper, we describe the deterministic solution of the neutron transport equation and the computation of the effective criticality of three-dimensional assemblies using the BBN TC2000 killer micros. We observe that the performance of our research code PTRAN running on 48 processors of the TC2000 is competitive with the partially vectorizable version running on a single Cray Y/MP processor. This performance scales well with the number of processors on real problems, including those that are not load balanced a priori. To obtain this performance, we explicitly specify and exploit data locality and data dependence using domain decomposition and dynamic job scheduling. From the results obtained here, it appears that, at least for this application, a production machine based on the TC2000 architecture with more powerful processors and a commensurate increase in switch speed could yield a significant gain in our design capability. 2 refs., 5 figs., 2 tabs.
Thermal 3D Modeling of Geothermal Area Using Terrestrial Photogrammetry
NASA Astrophysics Data System (ADS)
Akcay, Ozgun; Cuneyt Erenoglu, Ramazan; Erenoglu, Oya; Yılmazturk, Ferruh; Karaca, Zeki
2015-04-01
Photogrammetry and computer vision, sciences producing high accuracy 3D models from digital images based on projective geometry. 3D models can also be produced using thermal camera images using photogrammetry and computer vision techniques. Thermal images are capable of displaying hotspots on geothermal areas as a heat source in details. In the research, Tuzla geothermal area in Çanakkale province of Turkey is inspected using imaging techniques of terrestrial photogrammetry. Both a digital camera Canon EOS 650D and an infrared camera Optris PI 450 are used to obtain images of the thermal site. Calibration parameters (focal length, principle point, distortion coefficients) of thermal and digital cameras are determined using the calibration test field at the laboratory before the field work. In order to provide the georeferencing and the robustness of the 3D model, aluminum discs having diameter of 30 centimeters as ground control points (GCPs) are set to the geothermal area appropriately before imaging. Aluminum targets are chosen as the GCP because they are determined on the image depending on the contrast reflectance rate of the aluminum. Using GNSS RTK receivers supplying ±1 cm accuracy positioning, GCPs are measured so as to implement photogrammetric process successfully with thermal images. Numerous corresponding points are detected on the overlapped images with image matching techniques. Later on, bundle block adjustment is applied to calculate the revised interior orientation parameters of camera and exterior orientation parameters of camera positions. The 3D model showing details of the surface temperatures of the geothermal area are produced with multi view stereo (MVS) technique. The technique is able to produce 3D representation (point cloud, mesh and textured surface) of the field from both the thermal and digital images. The research presents that photogrammetric evaluation of thermal images is a noteworthy method to obtain a quick- accurate 3D
3D geometric modelling of hand-woven textile
NASA Astrophysics Data System (ADS)
Shidanshidi, H.; Naghdy, F.; Naghdy, G.; Conroy, D. Wood
2008-02-01
Geometric modeling and haptic rendering of textile has attracted significant interest over the last decade. A haptic representation is created by adding the physical properties of an object to its geometric configuration. While research has been conducted into geometric modeling of fabric, current systems require time-consuming manual recognition of textile specifications and data entry. The development of a generic approach for construction of the 3D geometric model of a woven textile is pursued in this work. The geometric model would be superimposed by a haptic model in the future work. The focus at this stage is on hand-woven textile artifacts for display in museums. A fuzzy rule based algorithm is applied to the still images of the artifacts to generate the 3D model. The derived model is exported as a 3D VRML model of the textile for visual representation and haptic rendering. An overview of the approach is provided and the developed algorithm is described. The approach is validated by applying the algorithm to different textile samples and comparing the produced models with the actual structure and pattern of the samples.
A biochemical/biophysical 3D FE intervertebral disc model.
Schroeder, Y; Huyghe, J M; van Donkelaar, C C; Ito, K
2010-10-01
Present research focuses on different strategies to preserve the degenerated disc. To assure long-term success of novel approaches, favorable mechanical conditions in the disc tissue are essential. To evaluate these, a model is required that can determine internal mechanical conditions which cannot be directly measured as a function of assessable biophysical characteristics. Therefore, the objective is to evaluate if constitutive and material laws acquired on isolated samples of nucleus and annulus tissue can be used directly in a whole-organ 3D FE model to describe intervertebral disc behavior. The 3D osmo-poro-visco-hyper-elastic disc (OVED) model describes disc behavior as a function of annulus and nucleus tissue biochemical composition, organization and specific constituent properties. The description of the 3D collagen network was enhanced to account for smaller fibril structures. Tissue mechanical behavior tests on isolated nucleus and annulus samples were simulated with models incorporating tissue composition to calculate the constituent parameter values. The obtained constitutive laws were incorporated into the whole-organ model. The overall behavior and disc properties of the model were corroborated against in vitro creep experiments of human L4/L5 discs. The OVED model simulated isolated tissue experiments on confined compression and uniaxial tensile test and whole-organ disc behavior. This was possible, provided that secondary fiber structures were accounted for. The fair agreement (radial bulge, axial creep deformation and intradiscal pressure) between model and experiment was obtained using constitutive properties that are the same for annulus and nucleus. Both tissue models differed in the 3D OVED model only by composition. The composition-based modeling presents the advantage of reducing the numbers of material parameters to a minimum and to use tissue composition directly as input. Hence, this approach provides the possibility to describe internal
Use Models like Maps in a 3D SDI
NASA Astrophysics Data System (ADS)
Gietzel, Jan; Gabriel, Paul; Schaeben, Helmut; Le, Hai Ha
2013-04-01
Digital geological applications have become 3D up to 4D modelling of the underground. The modellers are working very heterogeneously in terms of its applied software systems. On the other hand the 3D/4D modelling of the subsurface has become part of the geological surveys all around the world. This implies a wide spread group of users working in different institutions aiming to work together on one subsurface model. Established 3D/4D-modelling software systems mainly use a file based approach to store data, which is in a high contrast to the needs of a central administrated and network based data transfer approach. At the department of geophysics and geo information sciences at the Technical University Bergakademie Freiberg, the GST system for managing 3D and 4D geosciences data in a databases system was developed and is now continued by the company GiGa infosystems. The GST-Framework includes a storage engine, a web service for sharing and a number of client software including a browser based client interface for visualising, accessing and manipulating geological CAD data. Including a check out system GST supports multi user editing on huge models, designed to manage seamless high resolution models of the subsurface. While working on complex projects various software is used for the creation of the model, the prediction of properties and final simulation. A problem rising from the use of several software is the interoperability of the models. Due to conversion errors different working groups use mainly different raw data. This results in different models, which have to be corrected with additional effort. One platform sharing the models is strongly demanded. One high potential solution is a centralized and software independent storage, which will be presented.
Robust 3D reconstruction system for human jaw modeling
NASA Astrophysics Data System (ADS)
Yamany, Sameh M.; Farag, Aly A.; Tazman, David; Farman, Allan G.
1999-03-01
This paper presents a model-based vision system for dentistry that will replace traditional approaches used in diagnosis, treatment planning and surgical simulation. Dentistry requires accurate 3D representation of the teeth and jaws for many diagnostic and treatment purposes. For example orthodontic treatment involves the application of force systems to teeth over time to correct malocclusion. In order to evaluate tooth movement progress, the orthodontists monitors this movement by means of visual inspection, intraoral measurements, fabrication of plastic models, photographs and radiographs, a process which is both costly and time consuming. In this paper an integrate system has been developed to record the patient's occlusion using computer vision. Data is acquired with an intraoral video camera. A modified shape from shading (SFS) technique, using perspective projection and camera calibration, is used to extract accurate 3D information from a sequence of 2D images of the jaw. A new technique for 3D data registration, using a Grid Closest Point transform and genetic algorithms, is used to register the SFS output. Triangulization is then performed, and a solid 3D model is obtained via a rapid prototype machine.
3D Geological modelling - towards a European level infrastructure
NASA Astrophysics Data System (ADS)
Lee, Kathryn A.; van der Krogt, Rob; Busschers, Freek S.
2013-04-01
The joint European Geological Surveys are preparing the ground for a "European Geological Data Infrastructure" (EGDI), under the framework of the FP7-project EGDI-Scope. This scoping study, started in June 2012, for a pan-European e-Infrastructure is based on the successes of earlier joint projects including 'OneGeology-Europe' and aims to provide the backbone for serving interoperable, geological data currently held by European Geological Surveys. Also data from past, ongoing and future European projects will be incorporated. The scope will include an investigation of the functional and technical requirements for serving 3D geological models and will look to research the potential for providing a framework to integrate models at different scales, and form a structure for enabling the development of new and innovative model delivery mechanisms. The EGDI-scope project encourages pan-European inter-disciplinary collaboration between all European Geological Surveys. It aims to enhance emerging web based technologies that will facilitate the delivery of geological data to user communities involved in European policy making and international industry, but also to geoscientific research communities and the general public. Therefore, stakeholder input and communication is imperative to the success, as is the collaboration with all the Geological Surveys of Europe. The most important functional and technical requirements for delivery of such information at pan-European level will be derived from exchanges with relevant European stakeholder representatives and providers of geological data. For handling and delivering 3D geological model data the project will need to address a number of strategic issues: • Which are the most important issues and queries for the relevant stakeholders, requiring 3D geological models? How can this be translated to functional requirements for development and design of an integrated European application? • How to handle the very large
3D Compressible Melt Transport with Adaptive Mesh Refinement
NASA Astrophysics Data System (ADS)
Dannberg, Juliane; Heister, Timo
2015-04-01
Melt generation and migration have been the subject of numerous investigations, but their typical time and length-scales are vastly different from mantle convection, which makes it difficult to study these processes in a unified framework. The equations that describe coupled Stokes-Darcy flow have been derived a long time ago and they have been successfully implemented and applied in numerical models (Keller et al., 2013). However, modelling magma dynamics poses the challenge of highly non-linear and spatially variable material properties, in particular the viscosity. Applying adaptive mesh refinement to this type of problems is particularly advantageous, as the resolution can be increased in mesh cells where melt is present and viscosity gradients are high, whereas a lower resolution is sufficient in regions without melt. In addition, previous models neglect the compressibility of both the solid and the fluid phase. However, experiments have shown that the melt density change from the depth of melt generation to the surface leads to a volume increase of up to 20%. Considering these volume changes in both phases also ensures self-consistency of models that strive to link melt generation to processes in the deeper mantle, where the compressibility of the solid phase becomes more important. We describe our extension of the finite-element mantle convection code ASPECT (Kronbichler et al., 2012) that allows for solving additional equations describing the behaviour of silicate melt percolating through and interacting with a viscously deforming host rock. We use the original compressible formulation of the McKenzie equations, augmented by an equation for the conservation of energy. This approach includes both melt migration and melt generation with the accompanying latent heat effects. We evaluate the functionality and potential of this method using a series of simple model setups and benchmarks, comparing results of the compressible and incompressible formulation and
Quasi-3D Multi-scale Modeling Framework Development
NASA Astrophysics Data System (ADS)
Arakawa, A.; Jung, J.
2008-12-01
When models are truncated in or near an energetically active range of the spectrum, model physics must be changed as the resolution changes. The model physics of GCMs and that of CRMs are, however, quite different from each other and at present there is no unified formulation of model physics that automatically provides transition between these model physics. The Quasi-3D (Q3D) Multi-scale Modeling Framework (MMF) is an attempt to bridge this gap. Like the recently proposed Heterogeneous Multiscale Method (HMM) (E and Engquist 2003), MMF combines a macroscopic model, GCM, and a microscopic model, CRM. Unlike the traditional multiscale methods such as the multi-grid and adapted mesh refinement techniques, HMM and MMF are for solving multi-physics problems. They share the common objective "to design combined macroscopic-microscopic computational methods that are much more efficient than solving the full microscopic model and at the same time give the information we need" (E et al. 2008). The question is then how to meet this objective in practice, which can be highly problem dependent. In HHM, the efficiency is gained typically by localization of the microscale problem. Following the pioneering work by Grabowski and Smolarkiewicz (1999) and Grabowski (2001), MMF takes advantage of the fact that 2D CRMs are reasonably successful in simulating deep clouds. In this approach, the efficiency is gained by sacrificing the three-dimensionality of cloud-scale motion. It also "localizes" the algorithm through embedding a CRM in each GCM grid box using cyclic boundary condition. The Q3D MMF is an attempt to reduce the expense due to these constraints by partially including the cloud-scale 3D effects and extending the CRM beyond individual GCM grid boxes. As currently formulated, the Q3D MMF is a 4D estimation/prediction framework that combines a GCM with a 3D anelastic cloud-resolving vector vorticity equation model (VVM) applied to a network of horizontal grids. The network
NASA Astrophysics Data System (ADS)
Mock, Samuel; Allenbach, Robin; Reynolds, Lance; Wehrens, Philip; Kurmann-Matzenauer, Eva; Kuhn, Pascal; Michael, Salomè; Di Tommaso, Gennaro; Herwegh, Marco
2016-04-01
The Swiss Molasse Basin comprises the western and central part of the North Alpine Foreland Basin. In recent years it has come under closer scrutiny due to its promising geopotentials such as geothermal energy and CO2 sequestration. In order to adress these topics good knowledge of the subsurface is a key prerequisite. For that matter, geological 3D models serve as valuable tools. In collaboration with the Swiss Geological Survey (swisstopo) and as part of the project GeoMol CH, a geological 3D model of the Swiss Molasse Basin in the Canton of Bern has been built. The model covers an area of 1810 km2and reaches depth of up to 6.7 km. It comprises 10 major Cenozoic and Mesozoic units and numerous faults. The 3D model is mainly based on 2D seismic data complemented by information from few deep wells. Additionally, data from geological maps and profiles were used for refinement at shallow depths. In total, 1163 km of reflection seismic data, along 77 seismic lines, have been interpreted by different authors with respect to stratigraphy and structures. Both, horizons and faults, have been interpreted in 2D and modelled in 3D using IHS's Kingdom Suite and Midland Valley's MOVE software packages, respectively. Given the variable degree of subsurface information available, each 3D model is subject of uncertainty. With the primary input data coming from interpretation of reflection seismic data, a variety of uncertainties comes into play. Some of them are difficult to address (e.g. author's style of interpretation) while others can be quantified (e.g. mis-tie correction, well-tie). An important source of uncertainties is the quality of seismic data; this affects the traceability and lateral continuation of seismic reflectors. By defining quality classes we can semi-quantify this source of uncertainty. In order to visualize the quality and density of the input data in a meaningful way, we introduce quality-weighted data density maps. In combination with the geological 3D
A method for building 3D models of barchan dunes
NASA Astrophysics Data System (ADS)
Nai, Yang; Li-lan, Su; Lin, Wan; Jie, Yang; Shi-yi, Chen; Wei-lu, Hu
2016-01-01
The distributions of barchan dunes are usually represented by digital terrain models (DTMs) overlaid with digital orthophoto maps. Given that most regions with barchan dues have low relief, a 3D map obtained from a DTM may ineffectively show the stereoscopic shape of each dune. The method of building 3D models of barchan dunes using existing modeling software seldom considers the geographical environment. As a result, barchan dune models are often inconsistent with actual DTMs and incompletely express the morphological characteristics of dunes. Manual construction of barchan dune models is also costly and time consuming. Considering these problems, the morphological characteristics of barchan dunes and the mathematical relationships between the morphological parameters of the dunes, such as length, height, and width, are analyzed in this study. The methods of extracting the morphological feature points of barchan dunes, calculating their morphological parameters and building dune outlines and skeleton lines based on the medial axes, are also presented. The dune outlines, skeleton lines, and part of the medial axes of dunes are used to construct a constrained triangulated irregular network. C# and ArcEngine are employed to build 3D models of barchan dunes automatically. Experimental results of a study conducted in Tengger Desert show that the method can be used to approximate the morphological characteristics of barchan dunes and is less time consuming than manual methods.
Geometric and colour data fusion for outdoor 3D models.
Merchán, Pilar; Adán, Antonio; Salamanca, Santiago; Domínguez, Vicente; Chacón, Ricardo
2012-01-01
This paper deals with the generation of accurate, dense and coloured 3D models of outdoor scenarios from scanners. This is a challenging research field in which several problems still remain unsolved. In particular, the process of 3D model creation in outdoor scenes may be inefficient if the scene is digitalized under unsuitable technical (specific scanner on-board camera) and environmental (rain, dampness, changing illumination) conditions. We address our research towards the integration of images and range data to produce photorealistic models. Our proposal is based on decoupling the colour integration and geometry reconstruction stages, making them independent and controlled processes. This issue is approached from two different viewpoints. On the one hand, given a complete model (geometry plus texture), we propose a method to modify the original texture provided by the scanner on-board camera with the colour information extracted from external images taken at given moments and under specific environmental conditions. On the other hand, we propose an algorithm to directly assign external images onto the complete geometric model, thus avoiding tedious on-line calibration processes. We present the work conducted on two large Roman archaeological sites dating from the first century A.D., namely, the Theatre of Segobriga and the Fori Porticus of Emerita Augusta, both in Spain. The results obtained demonstrate that our approach could be useful in the digitalization and 3D modelling fields. PMID:22969327
Transport of iron oxide nanoparticles in saturated porous media: a large-scale 3D study
NASA Astrophysics Data System (ADS)
Velimirovic, Milica; Schmid, Doris; Micić, Vesna; Miyajima, Kumiko; Klaas, Norbert; Braun, Jürgen; Bosch, Julian; Meckenstock, Rainer; von der Kammer, Frank; Hofmann, Thilo
2016-04-01
Iron oxide nanoparticles (FeOxNp) have a high potential as electron acceptor for in situ microbial oxidation of a wide range of recalcitrant groundwater contaminants (Bosch et al., 2010). Tosco et al. (2012) reported on high colloidal stability of FeOxNp dispersed in water, their low deposition behavior, and consequently improved transport in column experiments compared to extensively studied zerovalent iron nanoparticles. However, determination of FeOxNp transport behavior at the field-relevant conditions has not been done before. The present work is aimed to evaluate different complementary methods for detection, quantification and transport characterization of FeOxNp in a large-scale three-dimensional (3D) model aquifer. Prior to that, batch-scale experiments were performed in order to elucidate the potential of the selected methods for direct and indirect characterization and detection of FeOxNp. Direct methods included measurements of particle size distribution, particle concentration, Fetot content and turbidity of the FeOxNp suspension. Indirect methods included measurements of particle zeta potential, as well as TOC content and pH of the FeOxNp suspension. The results of the batch experiments indicated that the most suitable approach for detecting and quantifying FeOxNp was measuring Fetot content and suspension turbidity, as well as particle size determined using dynamic light scattering principle. These complementary methods were further applied in a large-scale 3D study containing medium and coarse sand in order to 1) assess the transport of FeOxNp in saturated porous medium during injection (VFeOx = 6 m3, cparticle = 20 g/L, Qinj = 0.7 m3/h), and 2) illustrate their spatial distribution after injection. The outcomes of the large-scale 3D study confirmed that FeOxNp transport can be successfully investigated applying complementary methods. Monitoring data including Fetot content, turbidity and particle size showed the transport of particles towards the
Towards a 3d Spatial Urban Energy Modelling Approach
NASA Astrophysics Data System (ADS)
Bahu, J.-M.; Koch, A.; Kremers, E.; Murshed, S. M.
2013-09-01
Today's needs to reduce the environmental impact of energy use impose dramatic changes for energy infrastructure and existing demand patterns (e.g. buildings) corresponding to their specific context. In addition, future energy systems are expected to integrate a considerable share of fluctuating power sources and equally a high share of distributed generation of electricity. Energy system models capable of describing such future systems and allowing the simulation of the impact of these developments thus require a spatial representation in order to reflect the local context and the boundary conditions. This paper describes two recent research approaches developed at EIFER in the fields of (a) geo-localised simulation of heat energy demand in cities based on 3D morphological data and (b) spatially explicit Agent-Based Models (ABM) for the simulation of smart grids. 3D city models were used to assess solar potential and heat energy demand of residential buildings which enable cities to target the building refurbishment potentials. Distributed energy systems require innovative modelling techniques where individual components are represented and can interact. With this approach, several smart grid demonstrators were simulated, where heterogeneous models are spatially represented. Coupling 3D geodata with energy system ABMs holds different advantages for both approaches. On one hand, energy system models can be enhanced with high resolution data from 3D city models and their semantic relations. Furthermore, they allow for spatial analysis and visualisation of the results, with emphasis on spatially and structurally correlations among the different layers (e.g. infrastructure, buildings, administrative zones) to provide an integrated approach. On the other hand, 3D models can benefit from more detailed system description of energy infrastructure, representing dynamic phenomena and high resolution models for energy use at component level. The proposed modelling strategies
3-D model-based tracking for UAV indoor localization.
Teulière, Céline; Marchand, Eric; Eck, Laurent
2015-05-01
This paper proposes a novel model-based tracking approach for 3-D localization. One main difficulty of standard model-based approach lies in the presence of low-level ambiguities between different edges. In this paper, given a 3-D model of the edges of the environment, we derive a multiple hypotheses tracker which retrieves the potential poses of the camera from the observations in the image. We also show how these candidate poses can be integrated into a particle filtering framework to guide the particle set toward the peaks of the distribution. Motivated by the UAV indoor localization problem where GPS signal is not available, we validate the algorithm on real image sequences from UAV flights. PMID:25099967
3D Multispectral Light Propagation Model For Subcutaneous Veins Imaging
Paquit, Vincent C; Price, Jeffery R; Meriaudeau, Fabrice; Tobin Jr, Kenneth William
2008-01-01
In this paper, we describe a new 3D light propagation model aimed at understanding the effects of various physiological properties on subcutaneous vein imaging. In particular, we build upon the well known MCML (Monte Carlo Multi Layer) code and present a tissue model that improves upon the current state-of-the-art by: incorporating physiological variation, such as melanin concentration, fat content, and layer thickness; including veins of varying depth and diameter; using curved surfaces from real arm shapes; and modeling the vessel wall interface. We describe our model, present results from the Monte Carlo modeling, and compare these results with those obtained with other Monte Carlo methods.
Texture blending on 3D models using casual images
NASA Astrophysics Data System (ADS)
Liu, Xingming; Liu, Xiaoli; Li, Ameng; Liu, Junyao; Wang, Huijing
2013-12-01
In this paper, a method for constructing photorealistic textured model using 3D structured light digitizer is presented. Our method acquisition of range images and texture images around object, and range images are registered and integrated to construct geometric model of object. System is calibrated and poses of texture-camera are determined so that the relationship between texture and geometric model is established. After that, a global optimization is applied to assign compatible texture to adjacent surface and followed with a level procedure to remove artifacts due to vary lighting, approximate geometric model and so on. Lastly, we demonstrate the effect of our method on constructing a real model of world.
Simulation of Current Generation in a 3-D Plasma Model
NASA Astrophysics Data System (ADS)
Tsung, F. S.; Dawson, J. M.
1996-11-01
In the advanced tokamak regime, transport phenomena can account for a signficant fraction of the toroidal current, possibly over that driven directly by the ohmic heating electric fields. Bootstrap theory accounts for contributions of the collisional modification of banana orbits on the toroidal currents. In our previous simulations in 21/2-D, currents were spontaneously generated in both the cylindrical and the toroidal geometries, contrary to neoclassical predictions. In these calculations, it was believed that the driving mechanism is the preferential loss of particles whose initial velocity is opposite to that of the plasma current. We are extending these simulations to three dimensions. A parallel 3-D electromagnetic PIC code running on the IBM SP2, with a localized field-solver has been developed to investigate the effects of perturbations parallel to the field lines, and direct comparisons has been made between the 21/2-D and 3-D simulations and we have found good agreements between the 2 1/2-D calculations and the 3-D results. We will present our new results at the meeting. Research partially supported by NSF and DOE.
A 3D alcoholic liver disease model on a chip.
Lee, JaeSeo; Choi, BongHwan; No, Da Yoon; Lee, GeonHui; Lee, Seung-Ri; Oh, HyunJik; Lee, Sang-Hoon
2016-03-14
Alcohol is one of the main causes of liver diseases, and the development of alcoholic liver disease (ALD) treatment methods has been one of the hottest issues. For this purpose, development of in vitro models mimicking the in vivo physiology is one of the critical requirements, and they help to determine the disease mechanisms and to discover the treatment method. Herein, a three-dimensional (3D) ALD model was developed and its superior features in mimicking the in vivo condition were demonstrated. A spheroid-based microfluidic chip was employed for the development of the 3D in vitro model of ALD progression. We co-cultured rat primary hepatocytes and hepatic stellate cells (HSCs) in a fluidic chip to investigate the role of HSCs in the recovery of liver with ALD. An interstitial level of flow derived by an osmotic pump was applied to the chip to provide in vivo mimicking of fluid activity. Using this in vitro tool, we were able to observe structural changes and decreased hepatic functions with the increase in ethanol concentration. The recovery process of liver injured by alcohol was observed by providing fresh culture medium to the damaged 3D liver tissue for few days. A reversibly- and irreversibly-injured ALD model was established. The proposed model can not only be used for the research of alcoholic disease mechanism, but also has the potential for use in studies of hepatotoxicity and drug screening applications. PMID:26857817
Two-equation turbulence modeling for 3-D hypersonic flows
NASA Technical Reports Server (NTRS)
Bardina, J. E.; Coakley, T. J.; Marvin, J. G.
1992-01-01
An investigation to verify, incorporate and develop two-equation turbulence models for three-dimensional high speed flows is presented. The current design effort of hypersonic vehicles has led to an intensive study of turbulence models for compressible hypersonic flows. This research complements an extensive review of experimental data and the current development of 2D turbulence models. The review of experimental data on 2D and 3D flows includes complex hypersonic flows with pressure profiles, skin friction, wall heat transfer, and turbulence statistics data. In a parallel effort, turbulence models for high speed flows have been tested against flat plate boundary layers, and are being tested against the 2D database. In the present paper, we present the results of 3D Navier-Stokes numerical simulations with an improved k-omega two-equation turbulence model against experimental data and empirical correlations of an adiabatic flat plate boundary layer, a cold wall flat plate boundary layer, and a 3D database flow, the interaction of an oblique shock wave and a thick turbulent boundary layer with a free stream Mach number = 8.18 and Reynolds number = 5 x 10 to the 6th.
Generation and use of human 3D-CAD models
NASA Astrophysics Data System (ADS)
Grotepass, Juergen; Speyer, Hartmut; Kaiser, Ralf
2002-05-01
Individualized Products are one of the ten mega trends of the 21st Century with human modeling as the key issue for tomorrow's design and product development. The use of human modeling software for computer based ergonomic simulations within the production process increases quality while reducing costs by 30- 50 percent and shortening production time. This presentation focuses on the use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production. Today, the entire production chain can be designed, individualized models generated and analyzed in 3D computer environments. Anthropometric design for ergonomics is matched to human needs, thus preserving health. Ergonomic simulation includes topics as human vision, reachability, kinematics, force and comfort analysis and international design capabilities. In German more than 17 billions of Mark are moved to other industries, because clothes do not fit. Individual clothing tailored to the customer's preference means surplus value, pleasure and perfect fit. The body scanning technology is the key to generation and use of human 3D-CAD models for both, the ergonomic design of working environments and made to measure garment production.
3D cartographic modeling of the Alpine arc
NASA Astrophysics Data System (ADS)
Vouillamoz, Naomi; Sue, Christian; Champagnac, Jean-Daniel; Calcagno, Philippe
2012-12-01
We built a 3D cartography of the Alpine arc, a highly non-cylindrical mountain belt, using the 3D GeoModeller of the BRGM (French geological survey). The model allows to handle the large-scale 3D structure of seventeen major crustal units of the belt (from the lower crust to the sedimentary cover nappes), and two main discontinuities (the Insubric Line and the Crustal Penninic Front). It provides a unique document to better understand their structural relationships and to produce new sections. The study area comprises the western Alpine arc, from the Jura to the Northwest, up to the Bergell granite intrusion and the Lepontine Dome to the East, and is limited to the South by the Ligurian basin. The model is limited vertically 10 km above sea level at the top, and the moho interface at the bottom. We discarded the structural relationships between the Alps sensus stricto and the surrounding geodynamic systems such as the Rhine graben or the connection with the Apennines. The 3D-model is based on the global integration of various data such as the DEM of the Alps, the moho isobaths, the simplified geological and tectonic maps of the belt, the crustal cross-sections ECORS-CROP and NFP-20, and complementary cross-sections specifically built to precise local complexities. The database has first been integrated in a GIS-project to prepare their implementation in the GeoModeller, by homogenizing the different spatial referencing systems. The global model is finally interpolated from all these data, using the potential field method. The final document is a new tri-dimensional cartography that would be used as input for further alpine studies.
3D modeling of dual-gate FinFET.
Mil'shtein, Samson; Devarakonda, Lalitha; Zanchi, Brian; Palma, John
2012-01-01
The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at Vg1 >Vg2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device. PMID:23148493
M3D-K simulations of sawteeth and energetic particle transport in tokamak plasmas
NASA Astrophysics Data System (ADS)
Shen, Wei; Fu, G. Y.; Sheng, Zheng-Mao; Breslau, J. A.; Wang, Feng
2014-09-01
Nonlinear simulations of sawteeth and related energetic particle transport are carried out using the kinetic/magnetohydrodynamic (MHD) hybrid code M3D-K. MHD simulations show repeated sawtooth cycles for a model tokamak equilibrium. Furthermore, test particle simulations are carried out to study the energetic particle transport due to a sawtooth crash. The results show that energetic particles are redistributed radially in the plasma core, depending on pitch angle and energy. For trapped particles, the redistribution occurs for particle energy below a critical value in agreement with existing theories. For co-passing particles, the redistribution is strong with little dependence on particle energy. In contrast, the redistribution level of counter-passing particles decreases with increasing particle energy.
M3D-K Simulations of Sawteeth and Energetic Particle Transport in Tokamak Plasmas
NASA Astrophysics Data System (ADS)
Shen, Wei; Fu, Guoyong; Sheng, Zhengmao; Breslau, Joshua; Wang, Feng
2013-10-01
Nonlinear simulations of Sawteeth and energetic particle transport are carried out using the kinetic/MHD hybrid code M3D-K. MHD simulations show repeated sawtooth cycles due to a resistive (1,1) internal kink mode for a model tokamak equilibrium. Furthermore, test particle simulations are carried out to study the energetic particle transport due to a sawtooth crash. The results show that energetic particles are redistributed radially in plasma core depending on pitch angle and energy. For trapped particles, the redistribution occurs for particle energy below a critical value in agreement with previous theory. For co-passing particles, the redistribution is strong with little dependence on particle energy. In contrast, the redistribution level of counter-passing particles decreases as particle energy becomes large.
M3D-K simulations of sawteeth and energetic particle transport in tokamak plasmas
Shen, Wei; Sheng, Zheng-Mao; Fu, G. Y.; Breslau, J. A.; Wang, Feng
2014-09-15
Nonlinear simulations of sawteeth and related energetic particle transport are carried out using the kinetic/magnetohydrodynamic (MHD) hybrid code M3D-K. MHD simulations show repeated sawtooth cycles for a model tokamak equilibrium. Furthermore, test particle simulations are carried out to study the energetic particle transport due to a sawtooth crash. The results show that energetic particles are redistributed radially in the plasma core, depending on pitch angle and energy. For trapped particles, the redistribution occurs for particle energy below a critical value in agreement with existing theories. For co-passing particles, the redistribution is strong with little dependence on particle energy. In contrast, the redistribution level of counter-passing particles decreases with increasing particle energy.
CityGML - Interoperable semantic 3D city models
NASA Astrophysics Data System (ADS)
Gröger, Gerhard; Plümer, Lutz
2012-07-01
CityGML is the international standard of the Open Geospatial Consortium (OGC) for the representation and exchange of 3D city models. It defines the three-dimensional geometry, topology, semantics and appearance of the most relevant topographic objects in urban or regional contexts. These definitions are provided in different, well-defined Levels-of-Detail (multiresolution model). The focus of CityGML is on the semantical aspects of 3D city models, its structures, taxonomies and aggregations, allowing users to employ virtual 3D city models for advanced analysis and visualization tasks in a variety of application domains such as urban planning, indoor/outdoor pedestrian navigation, environmental simulations, cultural heritage, or facility management. This is in contrast to purely geometrical/graphical models such as KML, VRML, or X3D, which do not provide sufficient semantics. CityGML is based on the Geography Markup Language (GML), which provides a standardized geometry model. Due to this model and its well-defined semantics and structures, CityGML facilitates interoperable data exchange in the context of geo web services and spatial data infrastructures. Since its standardization in 2008, CityGML has become used on a worldwide scale: tools from notable companies in the geospatial field provide CityGML interfaces. Many applications and projects use this standard. CityGML is also having a strong impact on science: numerous approaches use CityGML, particularly its semantics, for disaster management, emergency responses, or energy-related applications as well as for visualizations, or they contribute to CityGML, improving its consistency and validity, or use CityGML, particularly its different Levels-of-Detail, as a source or target for generalizations. This paper gives an overview of CityGML, its underlying concepts, its Levels-of-Detail, how to extend it, its applications, its likely future development, and the role it plays in scientific research. Furthermore, its
The 3D model control of image processing
NASA Technical Reports Server (NTRS)
Nguyen, An H.; Stark, Lawrence
1989-01-01
Telerobotics studies remote control of distant robots by a human operator using supervisory or direct control. Even if the robot manipulators has vision or other senses, problems arise involving control, communications, and delay. The communication delays that may be expected with telerobots working in space stations while being controlled from an Earth lab have led to a number of experiments attempting to circumvent the problem. This delay in communication is a main motivating factor in moving from well understood instantaneous hands-on manual control to less well understood supervisory control; the ultimate step would be the realization of a fully autonomous robot. The 3-D model control plays a crucial role in resolving many conflicting image processing problems that are inherent in resolving in the bottom-up approach of most current machine vision processes. The 3-D model control approach is also capable of providing the necessary visual feedback information for both the control algorithms and for the human operator.
3D root canal modeling for advanced endodontic treatment
NASA Astrophysics Data System (ADS)
Hong, Shane Y.; Dong, Janet
2002-06-01
More than 14 million teeth receive endodontic (root canal) treatment annually. Before a clinician's inspection and diagnosis, destructive access preparation by removing teeth crown and dentin is usually needed. This paper presents a non-invasive method for accessing internal tooth geometry by building 3-D tooth model from 2-D radiographic and endoscopic images to be used for an automatic prescription system of computer-aided treatment procedure planning, and for the root canal preparation by an intelligent micro drilling machine with on-line monitoring. It covers the techniques specific for dental application in the radiographic images acquirement, image enhancement, image segmentation and feature recognition, distance measurement and calibration, merging 2D image into 3D mathematical model representation and display. Included also are the methods to form references for irregular teeth geometry and to do accurately measurement with self-calibration.
3D modeling of high-Tc superconductors by finite element software
NASA Astrophysics Data System (ADS)
Zhang, Min; Coombs, T. A.
2012-01-01
A three-dimensional (3D) numerical model is proposed to solve the electromagnetic problems involving transport current and background field of a high-Tc superconducting (HTS) system. The model is characterized by the E-J power law and H-formulation, and is successfully implemented using finite element software. We first discuss the model in detail, including the mesh methods, boundary conditions and computing time. To validate the 3D model, we calculate the ac loss and trapped field solution for a bulk material and compare the results with the previously verified 2D solutions and an analytical solution. We then apply our model to test some typical problems such as superconducting bulk array and twisted conductors, which cannot be tackled by the 2D models. The new 3D model could be a powerful tool for researchers and engineers to investigate problems with a greater level of complicity.
Modeling 3D faces from samplings via compressive sensing
NASA Astrophysics Data System (ADS)
Sun, Qi; Tang, Yanlong; Hu, Ping
2013-07-01
3D data is easier to acquire for family entertainment purpose today because of the mass-production, cheapness and portability of domestic RGBD sensors, e.g., Microsoft Kinect. However, the accuracy of facial modeling is affected by the roughness and instability of the raw input data from such sensors. To overcome this problem, we introduce compressive sensing (CS) method to build a novel 3D super-resolution scheme to reconstruct high-resolution facial models from rough samples captured by Kinect. Unlike the simple frame fusion super-resolution method, this approach aims to acquire compressed samples for storage before a high-resolution image is produced. In this scheme, depth frames are firstly captured and then each of them is measured into compressed samples using sparse coding. Next, the samples are fused to produce an optimal one and finally a high-resolution image is recovered from the fused sample. This framework is able to recover 3D facial model of a given user from compressed simples and this can reducing storage space as well as measurement cost in future devices e.g., single-pixel depth cameras. Hence, this work can potentially be applied into future applications, such as access control system using face recognition, and smart phones with depth cameras, which need high resolution and little measure time.
3D numerical simulation of the transport of chemical signature compounds from buried landmines
NASA Astrophysics Data System (ADS)
Irrazabal, Maik; Borrero, Ernesto; Briano, Julio G.; Castro, Miguel; Hernandez, Samuel P.
2005-06-01
The transport of the chemical signature compounds from buried landmines in a three-dimensional (3D) array has been numerically modeled using the finite-volume technique. Compounds such as trinitrotoluene, dinitrotoluene, and their degradation products, are semi volatile and somewhat soluble in water. Furthermore, they can strongly adsorb to the soil and undergo chemical and biological degradation. Consequently, the spatial and temporal concentration distributions of such chemicals depend on the mobility of the water and gaseous phases, their molecular and mechanical diffusion, adsorption characteristics, soil water content, compaction, and environmental factors. A 3D framework is required since two-dimensional (2D) symmetry may easily fade due to terrain topography: non-flat surfaces, soil heterogeneity, or underground fractures. The spatial and temporal distribution of the chemical-signature-compounds, in an inclined grid has been obtained. The fact that the chemicals may migrate horizontally, giving higher surface concentrations at positions not directly on top of the objects, emphasizes the need for understanding the transport mechanism when a chemical detector is used. Deformation in the concentration contours after rainfall is observed in the inclined surface and is attributed to both: the advective flux, and to the water flux at the surface caused by the slope. The analysis of the displacements in the position of the maximum concentrations at the surface, respect to the actual location of the mine, in an inclined system, is presented.
3D modelling of the Black Sea ecosystem
NASA Astrophysics Data System (ADS)
Capet, A.; Gregoire, M.; Beckers, J.-M.; Joassin, P.; Naithani, J.; Soetart, K.
2009-04-01
A coupled physical-biogeochemical model has been developed to simulate the ecosystem of the Black Sea at the end of the 80's when eutrophication and invasion by gelatinous organisms seriously affected the stability and dynamics of the system. The biogeochemical model describes the cycle of carbon, nitrogen, silicate, oxygen and phosphorus through the foodweb from bacteria to gelatinous carnivores and explicitly represents processes in the anoxic layer down to the bottom. For calibration and analyses purposes, the coupled model has first been run in 1D at several places in the Black Sea. The biogeochemical model involves some hundred parameters which have been first calibrated by hand using published values. Then, an identifiability analysis has been performed in order to determine a subset of 15 identifiable parameters. An automatic calibration subroutine has been used to fine tune these parameters. In 1D, the model solution exhibits a complex dynamics with several years of transient adjustment. This complexity is imparted by the explicit modelling of top predators. The model has been calibrated and validated using a large set of data available in the Black Sea TU Ocean Base. The calibrated biogeochemical model is implemented in a 3D hydrodynamical model of the Black Sea. Results of these 3D simulations will be presented and compared with maps of in-situ data reconstructed from available data base using the software DIVA (Data Interpolation and Variational analysis).
2D quantum double models from a 3D perspective
NASA Astrophysics Data System (ADS)
Bernabé Ferreira, Miguel Jorge; Padmanabhan, Pramod; Teotonio-Sobrinho, Paulo
2014-09-01
In this paper we look at three dimensional (3D) lattice models that are generalizations of the state sum model used to define the Kuperberg invariant of 3-manifolds. The partition function is a scalar constructed as a tensor network where the building blocks are tensors given by the structure constants of an involutory Hopf algebra A. These models are very general and are hard to solve in its entire parameter space. One can obtain familiar models, such as ordinary gauge theories, by letting A be the group algebra {C}(G) of a discrete group G and staying on a certain region of the parameter space. We consider the transfer matrix of the model and show that quantum double Hamiltonians are derived from a particular choice of the parameters. Such a construction naturally leads to the star and plaquette operators of the quantum double Hamiltonians, of which the toric code is a special case when A={C}({{{Z}}_{2}}). This formulation is convenient to study ground states of these generalized quantum double models where they can naturally be interpreted as tensor network states. For a surface Σ, the ground state degeneracy is determined by the Kuperberg 3-manifold invariant of \\Sigma \\times {{S}^{1}}. It is also possible to obtain extra models by simply enlarging the allowed parameter space but keeping the solubility of the model. While some of these extra models have appeared before in the literature, our 3D perspective allows for an uniform description of them.
West Flank Coso, CA FORGE 3D geologic model
Doug Blankenship
2016-03-01
This is an x,y,z file of the West Flank FORGE 3D geologic model. Model created in Earthvision by Dynamic Graphic Inc. The model was constructed with a grid spacing of 100 m. Geologic surfaces were extrapolated from the input data using a minimum tension gridding algorithm. The data file is tabular data in a text file, with lithology data associated with X,Y,Z grid points. All the relevant information is in the file header (the spatial reference, the projection etc.) In addition all the fields in the data file are identified in the header.
3D Neutron Transport PWR Full-core Calculation with RMC code
NASA Astrophysics Data System (ADS)
Qiu, Yishu; She, Ding; Fan, Xiao; Wang, Kan; Li, Zeguang; Liang, Jingang; Leroyer, Hadrien
2014-06-01
Nowadays, there are more and more interests in the use of Monte Carlo codes to calculate the detailed power density distributions in full-core reactors. With the Inspur TS1000 HPC Server of Tsinghua University, several calculations have been done based on the EDF 3D Neutron Transport PWR Full-core benchmark through large-scale parallelism. To investigate and compare the results of the deterministic method and Monte Carlo method, EDF R&D and Department of Engineering Physics of Tsinghua University are having a collaboration to make code to code verification. So in this paper, two codes are used. One is the code COCAGNE developed by the EDF R&D, a deterministic core code, and the other is the Monte Carlo code RMC developed by Department of Engineering Physics in Tsinghua University. First, the full-core model is described and a 26-group calculation was performed by these two codes using the same 26-group cross-section library provided by EDF R&D. Then the parallel and tally performance of RMC is discussed. RMC employs a novel algorithm which can cut down most of the communications. It can be seen clearly that the speedup ratio almost linearly increases with the nodes. Furthermore the cell-mapping method applied by RMC consumes little time to tally even millions of cells. The results of the codes COCAGNE and RMC are compared in three ways. The results of these two codes agree well with each other. It can be concluded that both COCAGNE and RMC are able to provide 3D-transport solutions associated with detailed power density distributions calculation in PWR full-core reactors. Finally, to investigate how many histories are needed to obtain a given standard deviation for a full 3D solution, the non-symmetrized condensed 2-group fluxes of RMC are discussed.
Right approach to 3D modeling using CAD tools
NASA Astrophysics Data System (ADS)
Baddam, Mounica Reddy
The thesis provides a step-by-step methodology to enable an instructor dealing with CAD tools to optimally guide his/her students through an understandable 3D modeling approach which will not only enhance their knowledge about the tool's usage but also enable them to achieve their desired result in comparatively lesser time. In the known practical field, there is particularly very little information available to apply CAD skills to formal beginners' training sessions. Additionally, advent of new software in 3D domain cumulates updating into a more difficult task. Keeping up to the industry's advanced requirements emphasizes the importance of more skilled hands in the field of CAD development, rather than just prioritizing manufacturing in terms of complex software features. The thesis analyses different 3D modeling approaches specified to the varieties of CAD tools currently available in the market. Utilizing performance-time databases, learning curves have been generated to measure their performance time, feature count etc. Based on the results, improvement parameters have also been provided for (Asperl, 2005).
Effective 3-D surface modeling for geographic information systems
NASA Astrophysics Data System (ADS)
Yüksek, K.; Alparslan, M.; Mendi, E.
2013-11-01
In this work, we propose a dynamic, flexible and interactive urban digital terrain platform (DTP) with spatial data and query processing capabilities of Geographic Information Systems (GIS), multimedia database functionality and graphical modeling infrastructure. A new data element, called Geo-Node, which stores image, spatial data and 3-D CAD objects is developed using an efficient data structure. The system effectively handles data transfer of Geo-Nodes between main memory and secondary storage with an optimized Directional Replacement Policy (DRP) based buffer management scheme. Polyhedron structures are used in Digital Surface Modeling (DSM) and smoothing process is performed by interpolation. The experimental results show that our framework achieves high performance and works effectively with urban scenes independent from the amount of spatial data and image size. The proposed platform may contribute to the development of various applications such as Web GIS systems based on 3-D graphics standards (e.g. X3-D and VRML) and services which integrate multi-dimensional spatial information and satellite/aerial imagery.
Northern California Seismic Attenuation: 3-D Qp and Qs models
NASA Astrophysics Data System (ADS)
Eberhart-Phillips, D. M.
2015-12-01
The northern California crust exhibits a wide range of rock types and deformation processes which produce pronounced heterogeneity in regional attenuation. Using local earthquakes, 3-D Qp and Qs crustal models have been obtained for this region which includes the San Andreas fault system, the Central Valley, the Sierra Nevada batholith, and the Mendocino subduction volcanic system. Path attenuation t* values were determined from P and S spectra of 959 spatially distributed earthquakes, magnitude 2.5-6.0 from 2005-2014, using 1254 stations from NCEDC networks and IRIS Mendocino and Sierra Nevada temporary arrays. The t* data were used in Q inversions, using existing hypocenters and 3-D velocity models, with basic 10-km node spacing. The uneven data coverage was accounted for with linking of nodes into larger areas in order to provide useful Q images across the 3-D volume. The results at shallow depth (< 2 km) show very low Q in the Sacramento Delta, the Eureka area, and parts of the Bay Area. In the brittle crust, fault zones that have high seismicity exhibit low Q. In the lower crust, low Q is observed along fault zones that have large cumulative displacement and have experienced grain size reduction. Underlying active volcanic areas, low Q features are apparent below 20-km depth. Moderately high Q is associated with igneous rocks of the Sierra Nevada and Salinian block, while the Franciscan subduction complex shows moderately low Q. The most prominent high Q feature is related to the Great Valley Ophiolite.
Effective 3-D surface modeling for geographic information systems
NASA Astrophysics Data System (ADS)
Yüksek, K.; Alparslan, M.; Mendi, E.
2016-01-01
In this work, we propose a dynamic, flexible and interactive urban digital terrain platform with spatial data and query processing capabilities of geographic information systems, multimedia database functionality and graphical modeling infrastructure. A new data element, called Geo-Node, which stores image, spatial data and 3-D CAD objects is developed using an efficient data structure. The system effectively handles data transfer of Geo-Nodes between main memory and secondary storage with an optimized directional replacement policy (DRP) based buffer management scheme. Polyhedron structures are used in digital surface modeling and smoothing process is performed by interpolation. The experimental results show that our framework achieves high performance and works effectively with urban scenes independent from the amount of spatial data and image size. The proposed platform may contribute to the development of various applications such as Web GIS systems based on 3-D graphics standards (e.g., X3-D and VRML) and services which integrate multi-dimensional spatial information and satellite/aerial imagery.
How do hydrodynamic instabilities affect 3D transport in geophysical vortices?
NASA Astrophysics Data System (ADS)
Wang, Peng; Özgökmen, Tamay M.
2015-03-01
Three-dimensional (3D) transport within geophysical vortices (e.g. ocean eddies) is important in understanding processes at a variety of scales, ranging from plankton production to climate variability. 3D transport can be affected by hydrodynamic instabilities of geophysical vortices; however, how the instabilities affecting 3D transport is not clear. Focusing on barotropic, inertial and 3D instabilities, we investigate the joint impacts of instabilities on 3D transport by using analytical methods and direct numerical simulations. We discover for the first time that material can be exchanged through 3D pathways which link a family of vortices generated by the instabilities in a single, initially unstable vortex. We also show that instabilities can increase the magnitude of vertical velocity, mixing rate and vertical material exchange. Besides, we find that instabilities can cause the kinetic energy wavenumber spectrum to have a power-law regime different than the classic regimes of k - 5 / 3 and k-3, and propose a new energy spectrum to interpret the non-classic regime.
3D Geologic Model of the San Diego Area
NASA Astrophysics Data System (ADS)
Danskin, W. R.; Cromwell, G.; Glockhoff, C.; Martin, D.
2015-12-01
Prior geologic studies of the San Diego area, including northern Baja California, Mexico, focused on site investigations, characterization of rock formations, or earthquake hazards. No comprehensive, quantitative model characterizing the three-dimensional (3D) geology of the entire area has been developed. The lack of such a model limits understanding of large-scale processes, such as development of ancient landforms, and groundwater movement and availability. To evaluate these regional processes, the United States Geological Survey (USGS) conducted a study to better understand the geologic structure of the San Diego area. A cornerstone of this study is the installation and analysis of 77 wells at 12 multiple-depth monitoring-well sites. Geologic information from these wells was combined with lithologic data from 81 oil exploration wells and municipal and private water wells, gravity and seismic interpretations, and paleontological interpretations. These data were analyzed in conjunction with geologic maps and digital elevation models to develop a 3D geologic model of the San Diego area, in particular of the San Diego embayment. Existing interpretations of regional surficial geology, faulting, and tectonic history provided the framework for this model, which was refined by independent evaluation of subsurface geology. Geologic formations were simplified into five sedimentary units (Quaternary, Plio-Pleistocene, Oligocene, Eocene and Cretaceous ages), and one basal crystalline unit (primarily Cretaceous and Jurassic). Complex fault systems are represented in the model by ten fault strands that maintain overall displacement. The 3D geologic model corroborates existing geologic concepts of the San Diego area, refines the extent of subsurface geology, and allows users to holistically evaluate subsurface structures and regional hydrogeology.
Modeling and Processing of Continuous 3D Elastic Wavefield Data
NASA Astrophysics Data System (ADS)
Milkereit, B.; Bohlen, T.
2001-12-01
Continuous seismic wavefields are excited by earthquake clustering, induced seismicity in reservoirs, and mining. In hydrocarbon reservoirs, for example, pore pressure changes and fluid flow (mass transfer) will cause incremental deviatoric stresses sufficient to trigger and sustain seismic activity. Here we address three aspects of seismic wavefields in three-dimensional heterogeneous media triggered by distributed sources in space and time: forward modeling, multichannel data processing, and source location imaging. A power law distribution of seismic sources (such as the Gutenberg-Richter law) is used for the modeling of viscoelastic/elastic wave propagation through a realistic earth model. 3D modeling provides new insight in the interaction of multi-source wavefields and the role of scale-dependend elastic model parameters on transmitted and reflected/back-scattered wavefields. There exists a strong correlation between the spatial properties of the compressional, shear wave and density perturbations and the lateral correlation length of the resulting reflected or transmitted seismic wavefields. Modeling is based on the implementation of 3D elastic/viscoelastic FD codes on massive parallel and/or distributed computing resources using MPI (message passing interface). For parallelization, large grid 3D earth models are decomposed into subvolume processing elements whereby each processing element is updating the wavefield within its portion of the grid. Processing of continuous seismic wavefields excited by multiple distributed sources is based on a combination of crosscorrelated or slowness-transformed array data and Kirchhoff or reverse time migration for source location or source volume imaging. The appearance of slowness in both migration and array data processing suggests the possibility of combining them into a single process. In order to place further constraints on the migration, the directivity properties of 3-component receiver arrays can be included in
Underwater 3d Modeling: Image Enhancement and Point Cloud Filtering
NASA Astrophysics Data System (ADS)
Sarakinou, I.; Papadimitriou, K.; Georgoula, O.; Patias, P.
2016-06-01
This paper examines the results of image enhancement and point cloud filtering on the visual and geometric quality of 3D models for the representation of underwater features. Specifically it evaluates the combination of effects from the manual editing of images' radiometry (captured at shallow depths) and the selection of parameters for point cloud definition and mesh building (processed in 3D modeling software). Such datasets, are usually collected by divers, handled by scientists and used for geovisualization purposes. In the presented study, have been created 3D models from three sets of images (seafloor, part of a wreck and a small boat's wreck) captured at three different depths (3.5m, 10m and 14m respectively). Four models have been created from the first dataset (seafloor) in order to evaluate the results from the application of image enhancement techniques and point cloud filtering. The main process for this preliminary study included a) the definition of parameters for the point cloud filtering and the creation of a reference model, b) the radiometric editing of images, followed by the creation of three improved models and c) the assessment of results by comparing the visual and the geometric quality of improved models versus the reference one. Finally, the selected technique is tested on two other data sets in order to examine its appropriateness for different depths (at 10m and 14m) and different objects (part of a wreck and a small boat's wreck) in the context of an ongoing research in the Laboratory of Photogrammetry and Remote Sensing.
Subduction zone guided waves: 3D modelling and attenuation effects
NASA Astrophysics Data System (ADS)
Garth, T.; Rietbrock, A.
2013-12-01
Waveform modelling is an important tool for understanding complex seismic structures such as subduction zone waveguides. These structures are often simplified to 2D structures for modelling purposes to reduce computational costs. In the case of subduction zone waveguide affects, 2D models have shown that dispersed arrivals are caused by a low velocity waveguide, inferred to be subducted oceanic crust and/or hydrated outer rise normal faults. However, due to the 2D modelling limitations the inferred seismic properties such as velocity contrast and waveguide thickness are still debated. Here we test these limitations with full 3D waveform modelling. For waveguide effects to be observable the waveform must be accurately modelled to relatively high frequencies (> 2 Hz). This requires a small grid spacing due to the high seismic velocities present in subduction zones. A large area must be modelled as well due to the long propagation distances (400 - 600 km) of waves interacting with subduction zone waveguides. The combination of the large model area and small grid spacing required means that these simulations require a large amount of computational resources, only available at high performance computational centres like the UK National super computer HECTOR (used in this study). To minimize the cost of modelling for such a large area, the width of the model area perpendicular to the subduction trench (the y-direction) is made as small as possible. This reduces the overall volume of the 3D model domain. Therefore the wave field is simulated in a model ';corridor' of the subduction zone velocity structure. This introduces new potential sources of error particularly from grazing wave side reflections in the y-direction. Various dampening methods are explored to reduce these grazing side reflections, including perfectly matched layers (PML) and more traditional exponential dampening layers. Defining a corridor model allows waveguide affects to be modelled up to at least 2
3D flare particle model for ShipIR/NTCS
NASA Astrophysics Data System (ADS)
Ramaswamy, Srinivasan; Vaitekunas, David A.
2016-05-01
A key component in any soft-kill response to an incoming guided missile is the flare /chaff decoy used to distract or seduce the seeker homing system away from the naval platform. This paper describes a new 3D flare particle model in the naval threat countermeasure simulator (NTCS) of the NATO-standard ship signature model (ShipIR), which provides independent control over the size and radial distribution of its signature. The 3D particles of each flare sub-munition are modelled stochastically and rendered using OpenGL z-buffering, 2D projection, and alpha-blending to produce a unique and time varying signature. A sensitivity analysis on each input parameter provides the data and methods needed to synthesize a model from an IR measurement of a decoy. The new model also eliminated artifacts and deficiencies in our previous model which prevented reliable tracks from the adaptive track gate algorithm already presented by Ramaswamy and Vaitekunas (2015). A sequence of scenarios are used to test and demonstrate the new flare model during a missile engagement.
3D finite element model for treatment of cleft lip
NASA Astrophysics Data System (ADS)
Jiao, Chun; Hong, Dongming; Lu, Hongbing; Wang, Jianqi; Lin, Qin; Liang, Zhengrong
2009-02-01
Cleft lip is a congenital facial deformity with high occurrence rate in China. Surgical procedure involving Millard or Tennison methods is usually employed for treatment of cleft lip. However, due to the elasticity of the soft tissues and the mechanical interaction between skin and maxillary, the occurrence rate of facial abnormality or dehisce is still high after the surgery, leading to multiple operations of the patient. In this study, a framework of constructing a realistic 3D finite element model (FEM) for the treatment of cleft lip has been established. It consists of two major steps. The first one is the reconstruction of a 3D geometrical model of the cleft lip from scanning CT data. The second step is the build-up of a FEM for cleft lip using the geometric model, where the material property of all the tetrahedrons was calculated from the CT densities directly using an empirical curve. The simulation results demonstrated (1) the deformation procedure of the model step-by-step when forces were applied, (2) the stress distribution inside the model, and (3) the displacement of all elements in the model. With the computer simulation, the minimal force of having the cleft be repaired is predicted, as well as whether a given force sufficient for the treatment of a specific individual. It indicates that the proposed framework could integrate the treatment planning with stress analysis based on a realistic patient model.
NASA Astrophysics Data System (ADS)
Norajitra, Tobias; Meinzer, Hans-Peter; Maier-Hein, Klaus H.
2015-03-01
During image segmentation, 3D Statistical Shape Models (SSM) usually conduct a limited search for target landmarks within one-dimensional search profiles perpendicular to the model surface. In addition, landmark appearance is modeled only locally based on linear profiles and weak learners, altogether leading to segmentation errors from landmark ambiguities and limited search coverage. We present a new method for 3D SSM segmentation based on 3D Random Forest Regression Voting. For each surface landmark, a Random Regression Forest is trained that learns a 3D spatial displacement function between the according reference landmark and a set of surrounding sample points, based on an infinite set of non-local randomized 3D Haar-like features. Landmark search is then conducted omni-directionally within 3D search spaces, where voxelwise forest predictions on landmark position contribute to a common voting map which reflects the overall position estimate. Segmentation experiments were conducted on a set of 45 CT volumes of the human liver, of which 40 images were randomly chosen for training and 5 for testing. Without parameter optimization, using a simple candidate selection and a single resolution approach, excellent results were achieved, while faster convergence and better concavity segmentation were observed, altogether underlining the potential of our approach in terms of increased robustness from distinct landmark detection and from better search coverage.
Bazhenov fm unconventional reservoir 3D geological modeling methodology
NASA Astrophysics Data System (ADS)
Telnova, A.; Baranov, V.; Bukhanov, N.
2016-03-01
The Bazhenov Formation has been studied for more than 50 years, but its petroleum potential, optimal STOIIP or resource estimation approaches, the methodology used to select a reservoir, determine its properties are still unclear. The distinctive features of bituminous shale are specific geochemical properties chosen as basic parameters to perform the geological modeling of the Bazhenov deposits and determine the key areas. The main objective of this paper is to choose an optimal 3D geological modeling algorithm and test conventional (petrophysical) and specific (geochemical) properties.
Towards Forward Modeling of 3D Heterogeneity in D" region
NASA Astrophysics Data System (ADS)
To, A.; Capdeville, Y.; Romanowicz, B.
2002-12-01
The presence of strong lateral heterogeneity in D" is now well documented. While tomographic modeling provides constraints on the large scale patterns, strong variations on shorter scales are best addressed by forward modeling. Appropriate tools are needed for forward modeling that will handle strong 3D heterogeneity, at relatively short periods and including diffracted waves. We use a coupled mode/SEM (Spectral Element Method) to compute synthetic seismograms in 3D models of the D" layer down to 1/12s. This coupled method (Capdeville, 2001) affords faster computations than SEM in cases where heterogeneity can be restricted to a specific layer. We compare them with observed waveforms for several events in the Western Pacific. Observed and synthetic travel time trends are very consistent, although in most cases the observed residuals are significantly larger. Waveform amplitudes are less consistent. In order to understand the origin of the amplitude difference, we test the effect of 3D heterogeneity on Sdiff phase. In particular, the results show opposite trends in the amplitude of Sdiff due to heterogeneity located near the CMB or well above it. This provides constraints on the location of the causative velocity heterogeneity. Because the forward modeling approach requires many iterations, the coupled mode/SEM approach is still computationally intensive. It is more efficient to use a less accurate traditional approach to first get closer to a final model, and only then use coupled mode/SEM to refine the model. Ray theory is the most expedient way to calculate travel times. However, it is an infinite frequency approximation and not appropriate to handle diffracting waves. We show that ray theory predicts larger travel time anomaly for Sdiff phase than the one obtained by coupled mode/SEM. Although it is based on a weak heterogeneity assumption, Non-linear Asymptotic Coupling Theory(NACT) (Li and Romanowicz, 1995) helps to overcome this difficulty. It can handle
Digital 3D Borobudur - Integration of 3D surveying and modeling techniques
NASA Astrophysics Data System (ADS)
Suwardhi, D.; Menna, F.; Remondino, F.; Hanke, K.; Akmalia, R.
2015-08-01
The Borobudur temple (Indonesia) is one of the greatest Buddhist monuments in the world, now listed as an UNESCO World Heritage Site. The present state of the temple is the result of restorations after being exposed to natural disasters several times. Today there is still a growing rate of deterioration of the building stones whose causes need further researches. Monitoring programs, supported at institutional level, have been effectively executed to observe the problem. The paper presents the latest efforts to digitally document the Borobudur Temple and its surrounding area in 3D with photogrammetric techniques. UAV and terrestrial images were acquired to completely digitize the temple, produce DEM, orthoimages and maps at 1:100 and 1:1000 scale. The results of the project are now employed by the local government organizations to manage the heritage area and plan new policies for the conservation and preservation of the UNESCO site. In order to help data management and policy makers, a web-based information system of the heritage area was also built to visualize and easily access all the data and achieved 3D results.
Discrete Method of Images for 3D Radio Propagation Modeling
NASA Astrophysics Data System (ADS)
Novak, Roman
2016-09-01
Discretization by rasterization is introduced into the method of images (MI) in the context of 3D deterministic radio propagation modeling as a way to exploit spatial coherence of electromagnetic propagation for fine-grained parallelism. Traditional algebraic treatment of bounding regions and surfaces is replaced by computer graphics rendering of 3D reflections and double refractions while building the image tree. The visibility of reception points and surfaces is also resolved by shader programs. The proposed rasterization is shown to be of comparable run time to that of the fundamentally parallel shooting and bouncing rays. The rasterization does not affect the signal evaluation backtracking step, thus preserving its advantage over the brute force ray-tracing methods in terms of accuracy. Moreover, the rendering resolution may be scaled back for a given level of scenario detail with only marginal impact on the image tree size. This allows selection of scene optimized execution parameters for faster execution, giving the method a competitive edge. The proposed variant of MI can be run on any GPU that supports real-time 3D graphics.
3D Building Evacuation Route Modelling and Visualization
NASA Astrophysics Data System (ADS)
Chan, W.; Armenakis, C.
2014-11-01
The most common building evacuation approach currently applied is to have evacuation routes planned prior to these emergency events. These routes are usually the shortest and most practical path from each building room to the closest exit. The problem with this approach is that it is not adaptive. It is not responsively configurable relative to the type, intensity, or location of the emergency risk. Moreover, it does not provide any information to the affected persons or to the emergency responders while not allowing for the review of simulated hazard scenarios and alternative evacuation routes. In this paper we address two main tasks. The first is the modelling of the spatial risk caused by a hazardous event leading to choosing the optimal evacuation route for a set of options. The second is to generate a 3D visual representation of the model output. A multicriteria decision making (MCDM) approach is used to model the risk aiming at finding the optimal evacuation route. This is achieved by using the analytical hierarchy process (AHP) on the criteria describing the different alternative evacuation routes. The best route is then chosen to be the alternative with the least cost. The 3D visual representation of the model displays the building, the surrounding environment, the evacuee's location, the hazard location, the risk areas and the optimal evacuation pathway to the target safety location. The work has been performed using ESRI's ArcGIS. Using the developed models, the user can input the location of the hazard and the location of the evacuee. The system then determines the optimum evacuation route and displays it in 3D.
Modeling the GFR with RELAP5-3D
Cliff B. Davis; Theron D. Marshall; K. D. Weaver
2005-09-01
Significant improvements have been made to the RELAP5-3D computer code for analysis of the Gas Fast Reactor (GFR). These improvements consisted of adding carbon dioxide as a working fluid, improving the turbine component, developing a compressor model, and adding the Gnielinski heat transfer correlation. The code improvements were validated, generally through comparisons with independent design calculations. A model of the power conversion unit of the GFR was developed. The model of the power conversion unit was coupled to a reactor model to develop a complete model of the GFR system. The RELAP5 model of the GFR was used to simulate two transients, one initiated by a reactor trip and the other initiated by a loss of load.
Testing Mercury Porosimetry with 3D Printed Porosity Models
NASA Astrophysics Data System (ADS)
Hasiuk, F.; Ewing, R. P.; Hu, Q.
2014-12-01
Mercury intrusion porosimetry is one of the most widely used techniques to study the porous nature of a geological and man-made materials. In the geosciences, it is commonly used to describe petroleum reservoir and seal rocks as well as to grade aggregates for the design of asphalt and portland cement concretes. It's wide utility stems from its ability to characterize a wide range of pore throat sizes (from nanometers to around a millimeter). The fundamental physical model underlying mercury intrusion porosimetry, the Washburn Equation, is based on the assumption that rock porosity can be described as a bundle of cylindrical tubes. 3D printing technology, also known as rapid prototyping, allows the construction of intricate and accurate models, exactly what is required to build models of rock porosity. We evaluate the applicability of the Washburn Equation by comparing properties (like porosity, pore and pore throat size distribution, and surface area) computed on digital porosity models (built from CT data, CAD designs, or periodic geometries) to properties measured via mercury intrusion porosimetry on 3D printed versions of the same digital porosity models.
3D model tools for architecture and archaeology reconstruction
NASA Astrophysics Data System (ADS)
Vlad, Ioan; Herban, Ioan Sorin; Stoian, Mircea; Vilceanu, Clara-Beatrice
2016-06-01
The main objective of architectural and patrimonial survey is to provide a precise documentation of the status quo of the surveyed objects (monuments, buildings, archaeological object and sites) for preservation and protection, for scientific studies and restoration purposes, for the presentation to the general public. Cultural heritage documentation includes an interdisciplinary approach having as purpose an overall understanding of the object itself and an integration of the information which characterize it. The accuracy and the precision of the model are directly influenced by the quality of the measurements realized on field and by the quality of the software. The software is in the process of continuous development, which brings many improvements. On the other side, compared to aerial photogrammetry, close range photogrammetry and particularly architectural photogrammetry is not limited to vertical photographs with special cameras. The methodology of terrestrial photogrammetry has changed significantly and various photographic acquisitions are widely in use. In this context, the present paper brings forward a comparative study of TLS (Terrestrial Laser Scanner) and digital photogrammetry for 3D modeling. The authors take into account the accuracy of the 3D models obtained, the overall costs involved for each technology and method and the 4th dimension - time. The paper proves its applicability as photogrammetric technologies are nowadays used at a large scale for obtaining the 3D model of cultural heritage objects, efficacious in their assessment and monitoring, thus contributing to historic conservation. Its importance also lies in highlighting the advantages and disadvantages of each method used - very important issue for both the industrial and scientific segment when facing decisions such as in which technology to invest more research and funds.
Exploiting Textured 3D Models for Developing Serious Games
NASA Astrophysics Data System (ADS)
Kontogianni, G.; Georgopoulos, A.
2015-08-01
Digital technologies have affected significantly many fields of computer graphics such as Games and especially the field of the Serious Games. These games are usually used for educational proposes in many fields such as Health Care, Military applications, Education, Government etc. Especially Digital Cultural Heritage is a scientific area that Serious Games are applied and lately many applications appear in the related literature. Realistic 3D textured models which have been produced using different photogrammetric methods could be a useful tool for the creation of Serious Game applications in order to make the final result more realistic and close to the reality. The basic goal of this paper is how 3D textured models which are produced by photogrammetric methods can be useful for developing a more realistic environment of a Serious Game. The application of this project aims at the creation of an educational game for the Ancient Agora of Athens. The 3D models used vary not only as far as their production methods (i.e. Time of Flight laser scanner, Structure from Motion, Virtual historical reconstruction etc.) is concerned, but also as far as their era as some of them illustrated according to their existing situation and some others according to how these monuments looked like in the past. The Unity 3D® game developing environment was used for creating this application, in which all these models were inserted in the same file format. For the application two diachronic virtual tours of the Athenian Agora were produced. The first one illustrates the Agora as it is today and the second one at the 2nd century A.D. Finally the future perspective for the evolution of this game is presented which includes the addition of some questions that the user will be able to answer. Finally an evaluation is scheduled to be performed at the end of the project.
The Engelbourg's ruins: from 3D TLS point cloud acquisition to 3D virtual and historic models
NASA Astrophysics Data System (ADS)
Koehl, Mathieu; Berger, Solveig; Nobile, Sylvain
2014-05-01
The Castle of Engelbourg was built at the beginning of the 13th century, at the top of the Schlossberg. It is situated on the territory of the municipality of Thann (France), at the crossroads of Alsace and Lorraine, and dominates the outlet of the valley of Thur. Its strategic position was one of the causes of its systematic destructions during the 17th century, and Louis XIV finished his fate by ordering his demolition in 1673. Today only few vestiges remain, of which a section of the main tower from about 7m of diameter and 4m of wide laying on its slice, unique characteristic in the regional castral landscape. It is visible since the valley, was named "the Eye of the witch", and became a key attraction of the region. The site, which extends over approximately one hectare, is for several years the object of numerous archaeological studies and is at the heart of a project of valuation of the vestiges today. It was indeed a key objective, among the numerous planned works, to realize a 3D model of the site in its current state, in other words, a virtual model "such as seized", exploitable as well from a cultural and tourist point of view as by scientists and in archaeological researches. The team of the ICube/INSA lab had in responsibility the realization of this model, the acquisition of the data until the delivery of the virtual model, thanks to 3D TLS and topographic surveying methods. It was also planned to integrate into this 3D model, data of 2D archives, stemming from series of former excavations. The objectives of this project were the following ones: • Acquisition of 3D digital data of the site and 3D modelling • Digitization of the 2D archaeological data and integration in the 3D model • Implementation of a database connected to the 3D model • Virtual Visit of the site The obtained results allowed us to visualize every 3D object individually, under several forms (point clouds, 3D meshed objects and models, etc.) and at several levels of detail
Recent progress in modelling 3D lithospheric deformation
NASA Astrophysics Data System (ADS)
Kaus, B. J. P.; Popov, A.; May, D. A.
2012-04-01
Modelling 3D lithospheric deformation remains a challenging task, predominantly because the variations in rock types, as well as nonlinearities due to for example plastic deformation result in sharp and very large jumps in effective viscosity contrast. As a result, there are only a limited number of 3D codes available, most of which are using direct solvers which are computationally and memory-wise very demanding. As a result, the resolutions for typical model runs are quite modest, despite the use of hundreds of processors (and using much larger computers is unlikely to bring much improvement in this situation). For this reason we recently developed a new 3D deformation code,called LaMEM: Lithosphere and Mantle Evolution Model. LaMEM is written on top of PETSc, and as a result it runs on massive parallel machines and we have a large number of iterative solvers available (including geometric and algebraic multigrid methods). As it remains unclear which solver combinations work best under which conditions, we have implemented most currently suggested methods (such as schur complement reduction or Fully coupled iterations). In addition, we can use either a finite element discretization (with Q1P0, stabilized Q1Q1 or Q2P-1 elements) or a staggered finite difference discretization for the same input geometry, which is based on a marker and cell technique). This gives us he flexibility to test various solver methodologies on the same model setup, in terms of accuracy, speed, memory usage etc. Here, we will report on some features of LaMEM, on recent code additions, as well as on some lessons we learned which are important for modelling 3D lithospheric deformation. Specifically we will discuss: 1) How we combine a particle-and-cell method to make it work with both a finite difference and a (lagrangian, eulerian or ALE) finite element formulation, with only minor code modifications code 2) How finite difference and finite element discretizations compare in terms of
Discussion of Source Reconstruction Models Using 3D MCG Data
NASA Astrophysics Data System (ADS)
Melis, Massimo De; Uchikawa, Yoshinori
In this study we performed the source reconstruction of magnetocardiographic signals generated by the human heart activity to localize the site of origin of the heart activation. The localizations were performed in a four compartment model of the human volume conductor. The analyses were conducted on normal subjects and on a subject affected by the Wolff-Parkinson-White syndrome. Different models of the source activation were used to evaluate whether a general model of the current source can be applied in the study of the cardiac inverse problem. The data analyses were repeated using normal and vector component data of the MCG. The results show that a distributed source model has the better accuracy in performing the source reconstructions, and that 3D MCG data allow finding smaller differences between the different source models.
Modeling moving systems with RELAP5-3D
Mesina, G. L.; Aumiller, David L.; Buschman, Francis X.; Kyle, Matt R.
2015-12-04
RELAP5-3D is typically used to model stationary, land-based reactors. However, it can also model reactors in other inertial and accelerating frames of reference. By changing the magnitude of the gravitational vector through user input, RELAP5-3D can model reactors on a space station or the moon. The field equations have also been modified to model reactors in a non-inertial frame, such as occur in land-based reactors during earthquakes or onboard spacecraft. Transient body forces affect fluid flow in thermal-fluid machinery aboard accelerating crafts during rotational and translational accelerations. It is useful to express the equations of fluid motion in the acceleratingmore » frame of reference attached to the moving craft. However, careful treatment of the rotational and translational kinematics is required to accurately capture the physics of the fluid motion. Correlations for flow at angles between horizontal and vertical are generated via interpolation where no experimental studies or data exist. The equations for three-dimensional fluid motion in a non-inertial frame of reference are developed. As a result, two different systems for describing rotational motion are presented, user input is discussed, and an example is given.« less
Modeling moving systems with RELAP5-3D
Mesina, G. L.; Aumiller, David L.; Buschman, Francis X.; Kyle, Matt R.
2015-12-04
RELAP5-3D is typically used to model stationary, land-based reactors. However, it can also model reactors in other inertial and accelerating frames of reference. By changing the magnitude of the gravitational vector through user input, RELAP5-3D can model reactors on a space station or the moon. The field equations have also been modified to model reactors in a non-inertial frame, such as occur in land-based reactors during earthquakes or onboard spacecraft. Transient body forces affect fluid flow in thermal-fluid machinery aboard accelerating crafts during rotational and translational accelerations. It is useful to express the equations of fluid motion in the accelerating frame of reference attached to the moving craft. However, careful treatment of the rotational and translational kinematics is required to accurately capture the physics of the fluid motion. Correlations for flow at angles between horizontal and vertical are generated via interpolation where no experimental studies or data exist. The equations for three-dimensional fluid motion in a non-inertial frame of reference are developed. As a result, two different systems for describing rotational motion are presented, user input is discussed, and an example is given.
Reassessing Geophysical Models of the Bushveld Complex in 3D
NASA Astrophysics Data System (ADS)
Cole, J.; Webb, S. J.; Finn, C.
2012-12-01
Conceptual geophysical models of the Bushveld Igneous Complex show three possible geometries for its mafic component: 1) Separate intrusions with vertical feeders for the eastern and western lobes (Cousins, 1959) 2) Separate dipping sheets for the two lobes (Du Plessis and Kleywegt, 1987) 3) A single saucer-shaped unit connected at depth in the central part between the two lobes (Cawthorn et al, 1998) Model three incorporates isostatic adjustment of the crust in response to the weight of the dense mafic material. The model was corroborated by results of a broadband seismic array over southern Africa, known as the Southern African Seismic Experiment (SASE) (Nguuri, et al, 2001; Webb et al, 2004). This new information about the crustal thickness only became available in the last decade and could not be considered in the earlier models. Nevertheless, there is still on-going debate as to which model is correct. All of the models published up to now have been done in 2 or 2.5 dimensions. This is not well suited to modelling the complex geometry of the Bushveld intrusion. 3D modelling takes into account effects of variations in geometry and geophysical properties of lithologies in a full three dimensional sense and therefore affects the shape and amplitude of calculated fields. The main question is how the new knowledge of the increased crustal thickness, as well as the complexity of the Bushveld Complex, will impact on the gravity fields calculated for the existing conceptual models, when modelling in 3D. The three published geophysical models were remodelled using full 3Dl potential field modelling software, and including crustal thickness obtained from the SASE. The aim was not to construct very detailed models, but to test the existing conceptual models in an equally conceptual way. Firstly a specific 2D model was recreated in 3D, without crustal thickening, to establish the difference between 2D and 3D results. Then the thicker crust was added. Including the less
3D simulation of the Cluster-Cluster Aggregation model
NASA Astrophysics Data System (ADS)
Li, Chao; Xiong, Hailing
2014-12-01
We write a program to implement the Cluster-Cluster Aggregation (CCA) model with java programming language. By using the simulation program, the fractal aggregation growth process can be displayed dynamically in the form of a three-dimensional (3D) figure. Meanwhile, the related kinetics data of aggregation simulation can be also recorded dynamically. Compared to the traditional programs, the program has better real-time performance and is more helpful to observe the fractal growth process, which contributes to the scientific study in fractal aggregation. Besides, because of adopting java programming language, the program has very good cross-platform performance.
A generic 3D kinetic model of gene expression
NASA Astrophysics Data System (ADS)
Zhdanov, Vladimir P.
2012-04-01
Recent experiments show that mRNAs and proteins can be localized both in prokaryotic and eukaryotic cells. To describe such situations, I present a 3D mean-field kinetic model aimed primarily at gene expression in prokaryotic cells, including the formation of mRNA, its translation into protein, and slow diffusion of these species. Under steady-state conditions, the mRNA and protein spatial distribution is described by simple exponential functions. The protein concentration near the gene transcribed into mRNA is shown to depend on the protein and mRNA diffusion coefficients and degradation rate constants.
Unstructured 3D grid toolbox for modeling and simulation
George, D.
1997-11-01
Computable 3D grids that accurately represent complex multimaterial geometries are essential for both static and time-dependent modeling and simulation. LaGriT, the grid toolbox developed at Los Alamos provides a sophisticated set of initial grid generation, grid maintenance and grid optimization tools. We present example grids that demonstrate the flexibility of the grid generator. Additionally, we present the results of an electrostatic calculation and a grain growth problem that illustrate the grid optimization features and the utility of the grid server architecture.
Simulation of 3D Global Wave Propagation Through Geodynamic Models
NASA Astrophysics Data System (ADS)
Schuberth, B.; Piazzoni, A.; Bunge, H.; Igel, H.; Steinle-Neumann, G.
2005-12-01
This project aims at a better understanding of the forward problem of global 3D wave propagation. We use the spectral element program "SPECFEM3D" (Komatitsch and Tromp, 2002a,b) with varying input models of seismic velocities derived from mantle convection simulations (Bunge et al., 2002). The purpose of this approach is to obtain seismic velocity models independently from seismological studies. In this way one can test the effects of varying parameters of the mantle convection models on the seismic wave field. In order to obtain the seismic velocities from the temperature field of the geodynamical simulations we follow a mineral physics approach. Assuming a certain mantle composition (e.g. pyrolite with CMASF composition) we compute the stable phases for each depth (i.e. pressure) and temperature by system Gibbs free energy minimization. Elastic moduli and density are calculated from the equations of state of the stable mineral phases. For this we use a mineral physics database derived from calorimetric experiments (enthalphy and entropy of formation, heat capacity) and EOS parameters.
Time-dependent 3-D dterministic transport on parallel architectures using Dantsys/MPI
Baker, R.S.; Alcouffe, R.E.
1996-12-31
In addition to the ability to solve the static transport equation, we have also incorporated time dependence into our parallel 3-D S{sub {ital N}} code DANTSYS/MPI. Using a semi-implicit scheme, DANTSYS/MPI is capable of performing time-dependent calculations for both fissioning and pure source driven problems. We have applied this to various types of problems such as nuclear well logging and prompt fission experiments. This paper describes the form of the time- dependent equations implemented, their solution strategies in DANTSYS/MPI including iteration acceleration, and the strategies used for time-step control. Results are presented for a model nuclear well logging calculation.
3D Model of Melt Distribution in Partially Molten Dunite
NASA Astrophysics Data System (ADS)
Garapic, G.; Faul, U.; Brisson, E.
2010-12-01
The currently existing model of grain-scale melt geometry in the Earth’s upper mantle is derived from theoretical considerations that stem from material science research, combined with relatively low-resolution observations of polished two-dimensional surfaces. This model predicts a simple, interconnected network of melt along three-grain edges in static surface energy equilibrium. However, due to a continuous rearrangements of neighboring grains caused by grain growth, melt forms complex shapes among the grains. As a result, it is impossible to construct a 3D image of the pore space from 2D surfaces, which makes it particularly challenging to resolve the current controversy on whether all two-grain boundaries are wetted or melt-free. We present a new method for reconstruction of the 3D pore space in partially molten rocks. The method consists of serial sectioning and high resolution imaging (Field Emission SEM) of polished surfaces, followed by image alignment and rendering. The ablation rate during serial sectioning is determined by measuring the depth of a laser hole by interferometry. We removed a total of 25 layers with a spacing of of 1.3.microns between layers. Each layer consists of a mosaic of images approximately 300 x 320 microns in size. Melt regions are identified within each layer by hand-digitizing SEM images. We obtain a 3D model by stacking the slices, registering each slice, and using alpha shapes as a surface reconstruction technique. The sample we investigated is a partially molten dunite consisting of Fo90 olivine with a mean grain size of 33 microns and 4% melt. It was run in a piston cylinder at 1350°C and 1 GPa for 432 hours to achieve steady state grain growth. Rendering of the 3D pore space shows that the larger melt pockets at multi-grain junctions change within only a few microns in depth, whereas thin inclusions along two-grain boundaries persist over the entire depth of the imaged volume, which is similar to the mean grain size
BioFVM: an efficient, parallelized diffusive transport solver for 3-D biological simulations
Ghaffarizadeh, Ahmadreza; Friedman, Samuel H.; Macklin, Paul
2016-01-01
Motivation: Computational models of multicellular systems require solving systems of PDEs for release, uptake, decay and diffusion of multiple substrates in 3D, particularly when incorporating the impact of drugs, growth substrates and signaling factors on cell receptors and subcellular systems biology. Results: We introduce BioFVM, a diffusive transport solver tailored to biological problems. BioFVM can simulate release and uptake of many substrates by cell and bulk sources, diffusion and decay in large 3D domains. It has been parallelized with OpenMP, allowing efficient simulations on desktop workstations or single supercomputer nodes. The code is stable even for large time steps, with linear computational cost scalings. Solutions are first-order accurate in time and second-order accurate in space. The code can be run by itself or as part of a larger simulator. Availability and implementation: BioFVM is written in C ++ with parallelization in OpenMP. It is maintained and available for download at http://BioFVM.MathCancer.org and http://BioFVM.sf.net under the Apache License (v2.0). Contact: paul.macklin@usc.edu. Supplementary information: Supplementary data are available at Bioinformatics online. PMID:26656933
ERIC Educational Resources Information Center
Rowe, Jeremy; Razdan, Anshuman
The Partnership for Research in Spatial Modeling (PRISM) project at Arizona State University (ASU) developed modeling and analytic tools to respond to the limitations of two-dimensional (2D) data representations perceived by affiliated discipline scientists, and to take advantage of the enhanced capabilities of three-dimensional (3D) data that…
Canada in 3D - Toward a Sustainable 3D Model for Canadian Geology from Diverse Data Sources
NASA Astrophysics Data System (ADS)
Brodaric, B.; Pilkington, M.; Snyder, D. B.; St-Onge, M. R.; Russell, H.
2015-12-01
Many big science issues span large areas and require data from multiple heterogeneous sources, for example climate change, resource management, and hazard mitigation. Solutions to these issues can significantly benefit from access to a consistent and integrated geological model that would serve as a framework. However, such a model is absent for most large countries including Canada, due to the size of the landmass and the fragmentation of the source data into institutional and disciplinary silos. To overcome these barriers, the "Canada in 3D" (C3D) pilot project was recently launched by the Geological Survey of Canada. C3D is designed to be evergreen, multi-resolution, and inter-disciplinary: (a) it is to be updated regularly upon acquisition of new data; (b) portions vary in resolution and will initially consist of four layers (surficial, sedimentary, crystalline, and mantle) with intermediary patches of higher-resolution fill; and (c) a variety of independently managed data sources are providing inputs, such as geophysical, 3D and 2D geological models, drill logs, and others. Notably, scalability concerns dictate a decentralized and interoperable approach, such that only key control objects, denoting anchors for the modeling process, are imported into the C3D database while retaining provenance links to original sources. The resultant model is managed in the database, contains full modeling provenance as well as links to detailed information on rock units, and is to be visualized in desktop and online environments. It is anticipated that C3D will become the authoritative state of knowledge for the geology of Canada at a national scale.
Comparative 3-D Modeling of tmRNA
Burks, Jody; Zwieb, Christian; Müller, Florian; Wower, Iwona; Wower, Jacek
2005-01-01
Background Trans-translation releases stalled ribosomes from truncated mRNAs and tags defective proteins for proteolytic degradation using transfer-messenger RNA (tmRNA). This small stable RNA represents a hybrid of tRNA- and mRNA-like domains connected by a variable number of pseudoknots. Comparative sequence analysis of tmRNAs found in bacteria, plastids, and mitochondria provides considerable insights into their secondary structures. Progress toward understanding the molecular mechanism of template switching, which constitutes an essential step in trans-translation, is hampered by our limited knowledge about the three-dimensional folding of tmRNA. Results To facilitate experimental testing of the molecular intricacies of trans-translation, which often require appropriately modified tmRNA derivatives, we developed a procedure for building three-dimensional models of tmRNA. Using comparative sequence analysis, phylogenetically-supported 2-D structures were obtained to serve as input for the program ERNA-3D. Motifs containing loops and turns were extracted from the known structures of other RNAs and used to improve the tmRNA models. Biologically feasible 3-D models for the entire tmRNA molecule could be obtained. The models were characterized by a functionally significant close proximity between the tRNA-like domain and the resume codon. Potential conformational changes which might lead to a more open structure of tmRNA upon binding to the ribosome are discussed. The method, described in detail for the tmRNAs of Escherichia coli, Bacillus anthracis, and Caulobacter crescentus, is applicable to every tmRNA. Conclusion Improved molecular models of biological significance were obtained. These models will guide in the design of experiments and provide a better understanding of trans-translation. The comparative procedure described here for tmRNA is easily adopted for the modeling the members of other RNA families. PMID:15958166
2D/1D approximations to the 3D neutron transport equation. I: Theory
Kelley, B. W.; Larsen, E. W.
2013-07-01
A new class of '2D/1D' approximations is proposed for the 3D linear Boltzmann equation. These approximate equations preserve the exact transport physics in the radial directions x and y and diffusion physics in the axial direction z. Thus, the 2D/1D equations are more accurate approximations of the 3D Boltzmann equation than the conventional 3D diffusion equation. The 2D/1D equations can be systematically discretized, to yield accurate simulation methods for 3D reactor core problems. The resulting solutions will be more accurate than 3D diffusion solutions, and less expensive to generate than standard 3D transport solutions. In this paper, we (i) show that the simplest 2D/1D equation has certain desirable properties, (ii) systematically discretize this equation, and (iii) derive a stable iteration scheme for solving the discrete system of equations. In a companion paper [1], we give numerical results that confirm the theoretical predictions of accuracy and iterative stability. (authors)
SEARCHBreast Workshop Proceedings: 3D Modelling of Breast Cancer.
Morrissey, Bethny; Blyth, Karen; Carter, Phil; Chelala, Claude; Holen, Ingunn; Jones, Louise; Speirs, Valerie
2015-12-01
SEARCHBreast, a UK initiative supported by the NC3Rs, organised a workshop entitled 3D Modelling of Breast Cancer. The workshop focused on providing researchers with solutions to overcome some of the perceived barriers to working with human-derived tumour cells, cell lines and tissues, namely: a) the limited access to human-derived material; and b) the difficulty in working with these samples. The workshop presentations provided constructive advice and information on how to best prepare human cells or tissues for further downstream applications. Techniques in developing primary cultures from patient samples, and considerations when preserving tissue slices, were discussed. A common theme throughout the workshop was the importance of ensuring that the cells are grown in conditions as similar to the in vivo microenvironment as possible. Comparisons of the advantages of several in vitro options, such as primary cell cultures, cell line cultures, explants or tissue slices, suggest that all offer great potential applications for breast cancer research, and highlight that it need not be a case of choosing one over the other. The workshop also offered cutting-edge examples of on-chip technologies and 3-D tumour modelling by using virtual pathology, which can contribute to clinically relevant studies and provide insights into breast cancer metastatic mechanisms. PMID:26753939
Dynamic deformable models for 3D MRI heart segmentation
NASA Astrophysics Data System (ADS)
Zhukov, Leonid; Bao, Zhaosheng; Gusikov, Igor; Wood, John; Breen, David E.
2002-05-01
Automated or semiautomated segmentation of medical images decreases interstudy variation, observer bias, and postprocessing time as well as providing clincally-relevant quantitative data. In this paper we present a new dynamic deformable modeling approach to 3D segmentation. It utilizes recently developed dynamic remeshing techniques and curvature estimation methods to produce high-quality meshes. The approach has been implemented in an interactive environment that allows a user to specify an initial model and identify key features in the data. These features act as hard constraints that the model must not pass through as it deforms. We have employed the method to perform semi-automatic segmentation of heart structures from cine MRI data.
Topological order in an exactly solvable 3D spin model
Bravyi, Sergey; Leemhuis, Bernhard; Terhal, Barbara M.
2011-04-15
Research highlights: RHtriangle We study exactly solvable spin model with six-qubit nearest neighbor interactions on a 3D face centered cubic lattice. RHtriangle The ground space of the model exhibits topological quantum order. RHtriangle Elementary excitations can be geometrically described as the corners of rectangular-shaped membranes. RHtriangle The ground space can encode 4g qubits where g is the greatest common divisor of the lattice dimensions. RHtriangle Logical operators acting on the encoded qubits are described in terms of closed strings and closed membranes. - Abstract: We study a 3D generalization of the toric code model introduced recently by Chamon. This is an exactly solvable spin model with six-qubit nearest-neighbor interactions on an FCC lattice whose ground space exhibits topological quantum order. The elementary excitations of this model which we call monopoles can be geometrically described as the corners of rectangular-shaped membranes. We prove that the creation of an isolated monopole separated from other monopoles by a distance R requires an operator acting on {Omega}(R{sup 2}) qubits. Composite particles that consist of two monopoles (dipoles) and four monopoles (quadrupoles) can be described as end-points of strings. The peculiar feature of the model is that dipole-type strings are rigid, that is, such strings must be aligned with face-diagonals of the lattice. For periodic boundary conditions the ground space can encode 4g qubits where g is the greatest common divisor of the lattice dimensions. We describe a complete set of logical operators acting on the encoded qubits in terms of closed strings and closed membranes.
The Transient 3-D Transport Coupled Code TORT-TD/ATTICA3D for High-Fidelity Pebble-Bed HTGR Analyses
NASA Astrophysics Data System (ADS)
Seubert, Armin; Sureda, Antonio; Lapins, Janis; Bader, Johannes; Laurien, Eckart
2012-01-01
This article describes the 3D discrete ordinates-based coupled code system TORT-TD/ATTICA3D that aims at steady state and transient analyses of pebble-bed high-temperature gas cooled reactors. In view of increasing computing power, the application of time-dependent neutron transport methods becomes feasible for best estimate evaluations of safety margins. The calculation capabilities of TORT-TD/ATTICA3D are presented along with the coupling approach, with focus on the time-dependent neutron transport features of TORT-TD. Results obtained for the OECD/NEA/NSC PBMR-400 benchmark demonstrate the transient capabilities of TORT-TD/ATTICA3D.
How Do Hydrodynamic Instabilities Affect 3D Transport in Geophysical Vortices?
NASA Astrophysics Data System (ADS)
Wang, P.; Ozgokmen, T. M.
2014-12-01
Understanding three-dimensional (3D) transport in ocean eddies is important for processes at a variety of scales, ranging from plankton production to climate variability. It is well known that geophysical vortices are subject to various hydrodynamic instabilities. Yet the influence of these instabilities on 3D material transport in vortex systems is not well investigated. Focusing on barotropic, inertial and 3D instabilities, we analyze these instabilities with normal-mode method, and reproduce their characteristics via highly-resolved numerical simulations using a spectral element Navier-Stokes solver. By comparing the simulation results of stable and unstable vortices, we investigate the joint impacts of instabilities on 3D transport through three major aspects: (i) energy transfer, (ii) overturning transport of the secondary circulation, and (iii) rates of vertical exchange and mixing. It is found that instabilities can enhance local nonlinear interactions and cause the kinetic energy wavenumber spectrum to have slopes between the conventional -5/3 and -3 at inertial ranges. The cascade of a new quantity is proposed to explain these non-conventional slopes. One of our main results is the discovery of material exchange between the central vortex and satellite vortices through 3D pathways, called funnels. These funnels modify the concept of elliptic regions that can trap material when confined to 2D dynamics. Thus, we show that a family of vortices, created by the hydrodynamic instabilities of the initially unstable vortex, can still continue to operate in unity in order to complete the 3D transport in these systems. We also show that flow instabilities can double the magnitude of vertical velocity, increase the rate of vertical exchange by an order of magnitude and enhance mixing rate more than 100%.
Development of an aquifer management model AQMAN3D
Puig, Juan Carlos; Rolon-Collazo, L. I.; Pagan-Trinidad, Ishmael
1990-01-01
A computer code that enables the use of the USGS Modular groundwater flow model for aquifermanagement modeling has been developed. Aquifermanagement techniques integrate groundwater flow modeling with linear quadratic optimization methods for the solution of various aquifer management problems. The model AQMAN3D, is a modified version of a previously developed two-dimensional AQMAN model. The idea of coupling the AQMAN model with the MODULAR model arose because actual groundwater flow systems behave in a three dimensional manner, therefore requiring treatment as such, and due to the widespread use of MODULAR. The use of the AQMAN3D model permits the implementation of the technique known as aquifer managementmodeling. A generalized approach to obtain an optimal solution to an aquifer management problem is proposed, and a sample test problem is presented to illustrate the use of the model. Even though the model provides the hydrologist with a new and powerful investigative tool, its applicability is limited to confined or quasiconfined systems.
Active Exploration of Large 3D Model Repositories.
Gao, Lin; Cao, Yan-Pei; Lai, Yu-Kun; Huang, Hao-Zhi; Kobbelt, Leif; Hu, Shi-Min
2015-12-01
With broader availability of large-scale 3D model repositories, the need for efficient and effective exploration becomes more and more urgent. Existing model retrieval techniques do not scale well with the size of the database since often a large number of very similar objects are returned for a query, and the possibilities to refine the search are quite limited. We propose an interactive approach where the user feeds an active learning procedure by labeling either entire models or parts of them as "like" or "dislike" such that the system can automatically update an active set of recommended models. To provide an intuitive user interface, candidate models are presented based on their estimated relevance for the current query. From the methodological point of view, our main contribution is to exploit not only the similarity between a query and the database models but also the similarities among the database models themselves. We achieve this by an offline pre-processing stage, where global and local shape descriptors are computed for each model and a sparse distance metric is derived that can be evaluated efficiently even for very large databases. We demonstrate the effectiveness of our method by interactively exploring a repository containing over 100 K models. PMID:26529460
Modeling tree crown dynamics with 3D partial differential equations.
Beyer, Robert; Letort, Véronique; Cournède, Paul-Henry
2014-01-01
We characterize a tree's spatial foliage distribution by the local leaf area density. Considering this spatially continuous variable allows to describe the spatiotemporal evolution of the tree crown by means of 3D partial differential equations. These offer a framework to rigorously take locally and adaptively acting effects into account, notably the growth toward light. Biomass production through photosynthesis and the allocation to foliage and wood are readily included in this model framework. The system of equations stands out due to its inherent dynamic property of self-organization and spontaneous adaptation, generating complex behavior from even only a few parameters. The density-based approach yields spatially structured tree crowns without relying on detailed geometry. We present the methodological fundamentals of such a modeling approach and discuss further prospects and applications. PMID:25101095
3D Tissue-Engineered Model of Ewing Sarcoma
Lamhamedi-Cherradi, Salah-Eddine; Santoro, Marco; Ramammoorthy, Vandhana; Menegaz, Brian A.; Bartholomeusz, Geoffrey; Iles, Lakesla R.; Amin, Hesham M.; Livingston, Andrew J.; Mikos, Antonios G.; Ludwig, Joseph A.
2015-01-01
Despite longstanding reliance upon monolayer culture for studying cancer cells, and numerous advantages from both a practical and experimental standpoint, a growing body of evidence suggests more complex three-dimensional (3D) models are necessary to properly mimic many of the critical hallmarks associated with the oncogenesis, maintenance and spread of Ewing sarcoma (ES), the second most common pediatric bone tumor. And as clinicians increasingly turn to biologically-targeted therapies that exert their effects not only on the tumor cells themselves, but also on the surrounding extracellular matrix, it is especially important that preclinical models evolve in parallel to reliably measure antineoplastic effects and possible mechanisms of de novo and acquired drug resistance. Herein, we highlight a number of innovative methods used to fabricate biomimetic ES tumors, encompassing both the surrounding cellular milieu and extracellular matrix (ECM), and suggest potential applications to advance our understanding of ES biology, preclinical drug testing, and personalized medicine. PMID:25109853
3D Model of the Eta Carinae Little Homunculus Nebula
NASA Astrophysics Data System (ADS)
Steffen, Wolfgang; Teodoro, Mairan; Madura, Thomas; Groh, Jose H.; Gull, Theodore R.; Corcoran, Michael F.; Damineli, Augusto; Hamaguchi, Kenji
2015-01-01
We extend our morpho-kinematic 3D modeling of the Homunculus nebula (Steffen et al., 2014) to the interior nested Little Homunculus. The model is based on spectroscopic observations from HST/STIS. We find that the structure of the interior Little Homunculus is rather flat in the polar regions and interacts with the main Homunculus nebula only on one side, towards the periastron direction of the binary orbit. Furthermore, the two lobes of the LH are misaligned, also towards the periastron direction. As an explanation for the misalignment we propose that, in both cases, shortly after the eruptions that created the bipolar nebulae from the primary star, the off-center wind of the secondary has pushed the ejecta towards the periastron directions, since the secondary is most of the time near the apastron. Future hydrodynamic simulations are warranted to confirm this scenario.
3D in vitro modeling of the central nervous system
Hopkins, Amy M.; DeSimone, Elise; Chwalek, Karolina; Kaplan, David L.
2015-01-01
There are currently more than 600 diseases characterized as affecting the central nervous system (CNS) which inflict neural damage. Unfortunately, few of these conditions have effective treatments available. Although significant efforts have been put into developing new therapeutics, drugs which were promising in the developmental phase have high attrition rates in late stage clinical trials. These failures could be circumvented if current 2D in vitro and in vivo models were improved. 3D, tissue-engineered in vitro systems can address this need and enhance clinical translation through two approaches: (1) bottom-up, and (2) top-down (developmental/regenerative) strategies to reproduce the structure and function of human tissues. Critical challenges remain including biomaterials capable of matching the mechanical properties and extracellular matrix (ECM) composition of neural tissues, compartmentalized scaffolds that support heterogeneous tissue architectures reflective of brain organization and structure, and robust functional assays for in vitro tissue validation. The unique design parameters defined by the complex physiology of the CNS for construction and validation of 3D in vitro neural systems are reviewed here. PMID:25461688
Polygonal Shapes Detection in 3d Models of Complex Architectures
NASA Astrophysics Data System (ADS)
Benciolini, G. B.; Vitti, A.
2015-02-01
A sequential application of two global models defined on a variational framework is proposed for the detection of polygonal shapes in 3D models of complex architectures. As a first step, the procedure involves the use of the Mumford and Shah (1989) 1st-order variational model in dimension two (gridded height data are processed). In the Mumford-Shah model an auxiliary function detects the sharp changes, i.e., the discontinuities, of a piecewise smooth approximation of the data. The Mumford-Shah model requires the global minimization of a specific functional to simultaneously produce both the smooth approximation and its discontinuities. In the proposed procedure, the edges of the smooth approximation derived by a specific processing of the auxiliary function are then processed using the Blake and Zisserman (1987) 2nd-order variational model in dimension one (edges are processed in the plane). This second step permits to describe the edges of an object by means of piecewise almost-linear approximation of the input edges themselves and to detects sharp changes of the first-derivative of the edges so to detect corners. The Mumford-Shah variational model is used in two dimensions accepting the original data as primary input. The Blake-Zisserman variational model is used in one dimension for the refinement of the description of the edges. The selection among all the boundaries detected by the Mumford-Shah model of those that present a shape close to a polygon is performed by considering only those boundaries for which the Blake-Zisserman model identified discontinuities in their first derivative. The output of the procedure are hence shapes, coming from 3D geometric data, that can be considered as polygons. The application of the procedure is suitable for, but not limited to, the detection of objects such as foot-print of polygonal buildings, building facade boundaries or windows contours. v The procedure is applied to a height model of the building of the Engineering
Advanced prior modeling for 3D bright field electron tomography
NASA Astrophysics Data System (ADS)
Sreehari, Suhas; Venkatakrishnan, S. V.; Drummy, Lawrence F.; Simmons, Jeffrey P.; Bouman, Charles A.
2015-03-01
Many important imaging problems in material science involve reconstruction of images containing repetitive non-local structures. Model-based iterative reconstruction (MBIR) could in principle exploit such redundancies through the selection of a log prior probability term. However, in practice, determining such a log prior term that accounts for the similarity between distant structures in the image is quite challenging. Much progress has been made in the development of denoising algorithms like non-local means and BM3D, and these are known to successfully capture non-local redundancies in images. But the fact that these denoising operations are not explicitly formulated as cost functions makes it unclear as to how to incorporate them in the MBIR framework. In this paper, we formulate a solution to bright field electron tomography by augmenting the existing bright field MBIR method to incorporate any non-local denoising operator as a prior model. We accomplish this using a framework we call plug-and-play priors that decouples the log likelihood and the log prior probability terms in the MBIR cost function. We specifically use 3D non-local means (NLM) as the prior model in the plug-and-play framework, and showcase high quality tomographic reconstructions of a simulated aluminum spheres dataset, and two real datasets of aluminum spheres and ferritin structures. We observe that streak and smear artifacts are visibly suppressed, and that edges are preserved. Also, we report lower RMSE values compared to the conventional MBIR reconstruction using qGGMRF as the prior model.
Ma, Nina K L; Lim, Jia Kai; Leong, Meng Fatt; Sandanaraj, Edwin; Ang, Beng Ti; Tang, Carol; Wan, Andrew C A
2016-02-01
A hierarchy of cellular stemness exists in certain cancers, and any successful strategy to treat such cancers would have to eliminate the self-renewing tumor-initiating cells at the apex of the hierarchy. The cellular microenvironment, in particular the extracellular matrix (ECM), is believed to have a role in regulating stemness. In this work, U251 glioblastoma cells are cultured on electrospun polystyrene (ESPS) scaffolds coated with an array of 7 laminin isoforms to provide a 3D model for stem cell-related genes and proteins expression studies. We observed collaboration between 3D context and laminins in promoting glioma stemness. Depending on the laminin isoform presented, U251 cells cultured on ESPS scaffolds (3D) exhibited increased expression of stemness markers compared to those cultured on tissue culture polystyrene (2D). Our results indicate the influence of 3D (versus 2D) context on integrin expression, specifically, the upregulation of the laminin-binding integrins alpha 6 and beta 4. By a colony forming assay, we showed enhanced clonogenicity of cells grown on ESPS scaffolds in collaboration with laminins 411, 421, 511 and 521. Evaluation of patient glioma databases demonstrated significant enrichment of integrin and ECM pathway networks in tumors of worse prognosis, consistent with our observations. The present results demonstrate how 3D versus 2D context profoundly affects ECM signaling, leading to stemness. PMID:26684838
Facile micropatterning of dual hydrogel systems for 3D models of neurite outgrowth.
Curley, J Lowry; Moore, Michael J
2011-12-15
Understanding how microenvironmental factors influence neurite growth is important to inform studies in nerve regeneration, plasticity, development, and neurophysiology. In vitro models attempting to more accurately mimic the physiological environment by provision of a 3D growth matrix may provide useful foundations. Some limitations of thick 3D culture models include hampered solute transport, less-robust neurite growth than on 2D substrates, and difficulty in achieving spatial control of growth. To this end, we describe a 3D dual hydrogel model for embryonic rat day 15 dorsal root ganglion tissue explant growth using a digital micromirror device for dynamic mask projection photolithography. The photolithography method developed allowed simple, reproducible, one-step fabrication of thick hydrogel constructs on a variety of substrates, including permeable cell culture inserts. The relationships between projected mask size, crosslinked hydrogel resolution, and gel thickness were characterized, and resolution was found generally to decrease with increasing gel thickness. Cell viability in thick (481 μm) hydrogel constructs was significantly greater on permeable supports than glass, suggesting transport limitations were somewhat alleviated. The observed neurite growth was abundant and occurred in a spatially controlled manner throughout the 3D environment, a crucial step in the quest for a more effective biomimetic model of neurite outgrowth. PMID:21936043
Facile micropatterning of dual hydrogel systems for 3D models of neurite outgrowth
Curley, J L; Moore, M J
2011-01-01
Understanding how microenvironmental factors influence neurite growth is important to inform studies in nerve regeneration, plasticity, development, and neurophysiology. In vitro models attempting to more accurately mimic the physiological environment by provision of a 3D growth matrix may provide useful foundations. Some limitations of thick 3D culture models include hampered solute transport, less-robust neurite growth than on 2D substrates, and difficulty in achieving spatial control of growth. To this end, we describe a 3D dual hydrogel model for embryonic rat day 15 dorsal root ganglion tissue explant growth using a digital micro-mirror device for dynamic mask projection photolithography. The photolithography method developed allowed simple, reproducible, one-step fabrication of thick hydrogel constructs on a variety of substrates, including permeable cell culture inserts. The relationships between projected mask size, crosslinked hydrogel resolution, and gel thickness were characterized, and resolution was found generally to decrease with increasing gel thickness. Cell viability in thick (481 μm) hydrogel constructs was significantly greater on permeable supports than glass, suggesting transport limitations were somewhat alleviated. The observed neurite growth was abundant and occurred in a spatially controlled manner throughout the 3D environment, a crucial step in the quest for a more effective biomimetic model of neurite outgrowth. PMID:21936043
3D density model of the Central Andes
NASA Astrophysics Data System (ADS)
Prezzi, Claudia B.; Götze, Hans-Jürgen; Schmidt, Sabine
2009-12-01
We developed a 3D density model of the continental crust, the subducted plate and the upper mantle of the Central Andes between 20-29°S and 74-61°W through the forward modelling of Bouguer anomaly. The goal of this contribution is to gain insight on the lithospheric structure integrating the available information (geophysical, geologic, petrologic, and geochemical) in a single model. The geometry of our model is defined and constrained by hypocentre location, reflection and refraction on and offshore seismic lines, travel time and attenuation tomography, receiver function analysis, magnetotelluric studies, thermal models and balanced structural cross-sections. The densities allocated to the different bodies are calculated considering petrologic and geochemical data and pressure and temperature conditions. The model consists of 31 parallel E-W vertical planes, where the continental crust comprises distinct bodies, which represent the different morphotectonic units of the Central Andes. We include a partial melting zone at midcrustal depths under the Altiplano-Puna (low-velocity zone) and consider the presence of a rheologically strong block beneath the Salar de Atacama basin, according to recent seismic studies. Contour maps of the depth of the continental Moho, the thickness of the lower crust and the depth to the bottom of the lithosphere below South America are produced. The possible percentage of partial melt in the Central Andes low-velocity zone is estimated. The residual anomaly is calculated by subtracting from the Bouguer anomaly the gravimetric effect of the modelled subducted slab and of the modelled Moho. Isostatic anomalies are calculated from regional and local isostatic Mohos calculated with and without internal loads, derived from our gravity model, which are then compared to the modelled continental Moho. This study contributes to a more detailed knowledge of the lithospheric structure of this region of the Andes and provides an integrated 3D
Faceless identification: a model for person identification using the 3D shape and 3D motion as cues
NASA Astrophysics Data System (ADS)
Klasen, Lena M.; Li, Haibo
1999-02-01
Person identification by using biometric methods based on image sequences, or still images, often requires a controllable and cooperative environment during the image capturing stage. In the forensic case the situation is more likely to be the opposite. In this work we propose a method that makes use of the anthropometry of the human body and human actions as cues for identification. Image sequences from surveillance systems are used, which can be seen as monocular image sequences. A 3D deformable wireframe body model is used as a platform to handle the non-rigid information of the 3D shape and 3D motion of the human body from the image sequence. A recursive method for estimating global motion and local shape variations is presented, using two recursive feedback systems.
NASA Astrophysics Data System (ADS)
Kerschke, Dorit; Schilling, Maik; Simon, Andreas; Wächter, Joachim
2014-05-01
The Energiewende and the increasing scarcity of raw materials will lead to an intensified utilization of the subsurface in Germany. Within this context, geological 3D modeling is a fundamental approach for integrated decision and planning processes. Initiated by the development of the European Geospatial Infrastructure INSPIRE, the German State Geological Offices started digitizing their predominantly analog archive inventory. Until now, a comprehensive 3D subsurface model of Brandenburg did not exist. Therefore the project B3D strived to develop a new 3D model as well as a subsequent infrastructure node to integrate all geological and spatial data within the Geodaten-Infrastruktur Brandenburg (Geospatial Infrastructure, GDI-BB) and provide it to the public through an interactive 2D/3D web application. The functionality of the web application is based on a client-server architecture. Server-sided, all available spatial data is published through GeoServer. GeoServer is designed for interoperability and acts as the reference implementation of the Open Geospatial Consortium (OGC) Web Feature Service (WFS) standard that provides the interface that allows requests for geographical features. In addition, GeoServer implements, among others, the high performance certified compliant Web Map Service (WMS) that serves geo-referenced map images. For publishing 3D data, the OGC Web 3D Service (W3DS), a portrayal service for three-dimensional geo-data, is used. The W3DS displays elements representing the geometry, appearance, and behavior of geographic objects. On the client side, the web application is solely based on Free and Open Source Software and leans on the JavaScript API WebGL that allows the interactive rendering of 2D and 3D graphics by means of GPU accelerated usage of physics and image processing as part of the web page canvas without the use of plug-ins. WebGL is supported by most web browsers (e.g., Google Chrome, Mozilla Firefox, Safari, and Opera). The web
The USGS 3D Seismic Velocity Model for Northern California
NASA Astrophysics Data System (ADS)
Brocher, T. M.; Aagaard, B.; Simpson, R. W.; Jachens, R. C.
2006-12-01
We present a new regional 3D seismic velocity model for Northern California for use in strong motion simulations of the 1906 San Francisco and other earthquakes. The model includes compressional-wave velocity (Vp), shear-wave velocity (Vs), density, and intrinsic attenuation (Qp, Qs). These properties were assigned for each rock type in a 3D geologic model derived from surface outcrops, boreholes, gravity and magnetic data, and seismic reflection, refraction, and tomography studies. A detailed description of the model, USGS Bay Area Velocity Model 05.1.0, is available online [http://www.sf06simulation.org/geology/velocitymodel]. For ground motion simulations Vs and Qs are more important parameters than Vp and Qp because the strongest ground motions are generated chiefly by shear and surface wave arrivals. Because Vp data are more common than Vs data, however, we first developed Vp versus depth relations for each rock type and then converted these to Vs versus depth relations. For the most important rock types in Northern California we compiled measurements of Vp versus depth using borehole logs, laboratory measurements on hand samples, seismic refraction profiles, and tomography models. These rock types include Salinian and Sierran granitic rocks, metagraywackes and greenstones of the Franciscan Complex, Tertiary and Mesozoic sedimentary and volcanic rocks, and Quaternary and Holocene deposits (Brocher, USGS OFR 05-1317, 2005). Vp versus depth curves were converted to Vs versus depth curves using new empirical nonlinear relations between Vs and Vp (Brocher, BSSA, 2005). These relations, showing that Poisson's ratio is a nonlinear function of Vp, were similarly based on compilations of diverse Vs and Vp measurements on a large suite of rock types, mainly from California and the Pacific Northwest. The model is distributed in a discretized form with routines to query the model using C++, C, and Fortran 77 programming languages. The geologic model was discretized at
The Stagger-grid: A grid of 3D stellar atmosphere models. IV. Limb darkening coefficients
NASA Astrophysics Data System (ADS)
Magic, Z.; Chiavassa, A.; Collet, R.; Asplund, M.
2015-01-01
Aims: We compute the emergent stellar spectra from the UV to far infrared for different viewing angles using realistic 3D model atmospheres for a large range in stellar parameters to predict the stellar limb darkening. Methods: We have computed full 3D LTE synthetic spectra based on 3D radiative hydrodynamic atmosphere models from the Stagger-grid in the ranges: Teff from 4000 to 7000 K, log g from 1.5 to 5.0, and [Fe/H], from -4.0 to +0.5. From the resulting intensities, we derived coefficients for the standard limb darkening laws considering a number of often-used photometric filters. Furthermore, we calculated theoretical transit light curves, in order to quantify the differences between predictions by the widely used 1D model atmosphere and our 3D models. Results: The 3D models are often found to predict steeper darkening towards the limb compared to the 1D models, mainly due to the temperature stratifications and temperature gradients being different in the 3D models compared to those predicted with 1D models based on the mixing length theory description of convective energy transport. The resulting differences in the transit light curves are rather small; however, these can be significant for high-precision observations of extrasolar transits, and are able to lower the residuals from the fits with 1D limb darkening profiles. Conclusions: We advocate the use of the new limb darkening coefficients provided for the standard four-parameter non-linear power law, which can fit the limb darkening more accurately than other choices. Full Table A.1 and the grid of spectra are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/573/A90, as well as at http://www.stagger-stars.net
A 3D Bubble Merger Model for RTI Mixing
NASA Astrophysics Data System (ADS)
Cheng, Baolian
2015-11-01
In this work we present a model for the merger processes of bubbles at the edge of an unstable acceleration driven mixing layer. Steady acceleration defines a self-similar mixing process, with a time-dependent inverse cascade of structures of increasing size. The time evolution is itself a renormalization group evolution. The model predicts the growth rate of a Rayleigh-Taylor chaotic fluid-mixing layer. The 3-D model differs from the 2-D merger model in several important ways. Beyond the extension of the model to three dimensions, the model contains one phenomenological parameter, the variance of the bubble radii at fixed time. The model also predicts several experimental numbers: the bubble mixing rate, the mean bubble radius, and the bubble height separation at the time of merger. From these we also obtain the bubble height to the radius aspect ratio, which is in good agreement with experiments. Applications to recent NIF and Omega experiments will be discussed. This work was performed under the auspices of the U.S. Department of Energy by the Los Alamos National Laboratory under Contract No. W-7405-ENG-36.
3-D numerical modeling of plume-induced subduction initiation
NASA Astrophysics Data System (ADS)
Baes, Marzieh; Gerya, taras; Sobolev, Stephan
2016-04-01
Investigation of mechanisms involved in formation of a new subduction zone can help us to better understand plate tectonics. Despite numerous previous studies, it is still unclear how and where an old oceanic plate starts to subduct beneath the other plate. One of the proposed scenarios for nucleation of subduction is plume-induced subduction initiation, which was investigated in detail, using 2-D models, by Ueda et al. (2008). Recently. Gerya et al. (2015), using 3D numerical models, proposed that plume-lithosphere interaction in the Archean led to the subduction initiation and onset of plate tectonic. In this study, we aim to pursue work of Ueda et al. (2008) by incorporation of 3-D thermo-mechanical models to investigate conditions leading to oceanic subduction initiation as a result of thermal-chemical mantle plume-lithosphere interaction in the modern earth. Results of our experiments show four different deformation regimes in response to plume-lithosphere interaction, that are a) self-sustaining subduction initiation where subduction becomes self-sustained, b) freezing subduction initiation where subduction stops at shallow depths, c) slab break-off where subducting circular slab breaks off soon after formation and d) plume underplating where plume does not pass through the lithosphere but spreads beneath it (failed subduction initiation). These different regimes depend on several parameters such as plume's size, composition and temperature, lithospheric brittle/plastic strength, age of the oceanic lithosphere and presence/absence of lithospheric heterogeneities. Results show that subduction initiates and becomes self-sustained when lithosphere is older than 10 Myr and non-dimensional ratio of the plume buoyancy force and lithospheric strength above the plume is higher than 2.
3D model generation using an airborne swarm
NASA Astrophysics Data System (ADS)
Clark, R. A.; Punzo, G.; Dobie, G.; MacLeod, C. N.; Summan, R.; Pierce, G.; Macdonald, M.; Bolton, G.
2015-03-01
Using an artificial kinematic field to provide co-ordination between multiple inspection UAVs, the authors herein demonstrate full 3D modelling capability based on a photogrammetric system. The operation of the system is demonstrated by generating a full 3D surface model of an intermediate level nuclear waste storage drum. Such drums require periodic inspection to ensure that drum distortion or corrosion is carefully monitored. Performing this inspection with multiple airborne platforms enables rapid inspection of structures that are inaccessible to on-surface remote vehicles and are in human-hazardous environments. A three-dimensional surface-meshed model of the target can then be constructed in post-processing through photogrammetry analysis of the visual inspection data. The inspection environment uses a tracking system to precisely monitor the position of each aerial vehicle within the enclosure. The vehicles used are commercially available Parrot AR. Drone quadcopters, controlled through a computer interface connected over an IEEE 802.11n (WiFi) network, implementing a distributed controller for each vehicle. This enables the autonomous and distributed elements of the control scheme to be retained, while alleviating the vehicles of the control algorithm's computational load. The control scheme relies on a kinematic field defined with the target at its centre. This field defines the trajectory for all the drones in the volume relative to the central target, enabling the drones to circle the target at a set radius while avoiding drone collisions. This function enables complete coverage along the height of the object, which is assured by transitioning to another inspection band only after completing circumferential coverage. Using a swarm of vehicles, the time until complete coverage can be significantly reduced.
3D model generation using an airborne swarm
Clark, R. A.; Punzo, G.; Macdonald, M.; Dobie, G.; MacLeod, C. N.; Summan, R.; Pierce, G.; Bolton, G.
2015-03-31
Using an artificial kinematic field to provide co-ordination between multiple inspection UAVs, the authors herein demonstrate full 3D modelling capability based on a photogrammetric system. The operation of the system is demonstrated by generating a full 3D surface model of an intermediate level nuclear waste storage drum. Such drums require periodic inspection to ensure that drum distortion or corrosion is carefully monitored. Performing this inspection with multiple airborne platforms enables rapid inspection of structures that are inaccessible to on-surface remote vehicles and are in human-hazardous environments. A three-dimensional surface-meshed model of the target can then be constructed in post-processing through photogrammetry analysis of the visual inspection data. The inspection environment uses a tracking system to precisely monitor the position of each aerial vehicle within the enclosure. The vehicles used are commercially available Parrot AR. Drone quadcopters, controlled through a computer interface connected over an IEEE 802.11n (WiFi) network, implementing a distributed controller for each vehicle. This enables the autonomous and distributed elements of the control scheme to be retained, while alleviating the vehicles of the control algorithm’s computational load. The control scheme relies on a kinematic field defined with the target at its centre. This field defines the trajectory for all the drones in the volume relative to the central target, enabling the drones to circle the target at a set radius while avoiding drone collisions. This function enables complete coverage along the height of the object, which is assured by transitioning to another inspection band only after completing circumferential coverage. Using a swarm of vehicles, the time until complete coverage can be significantly reduced.
The 3-D world modeling with updating capability based on combinatorial geometry
NASA Technical Reports Server (NTRS)
Goldstein, M.; Pin, F. G.; Desaussure, G.; Weisbin, C. R.
1987-01-01
A 3-D world modeling technique using range data is discribed. Range data quantify the distances from the sensor focal plane to the object surface, i.e., the 3-D coordinates of discrete points on the object surface are known. The approach proposed herein for 3-D world modeling is based on the Combinatorial Geometry (CG) method which is widely used in Monte Carlo particle transport calculations. First, each measured point on the object surface is surrounded by a small sphere with a radius determined by the range to that point. Then, the 3-D shapes of the visible surfaces are obtained by taking the (Boolean) union of all the spheres. The result is an unambiguous representation of the object's boundary surfaces. The pre-learned partial knowledge of the environment can be also represented using the CG Method with a relatively small amount of data. Using the CG type of representation, distances in desired directions to boundary surfaces of various objects are efficiently calculated. This feature is particularly useful for continuously verifying the world model against the data provided by a range finder, and for integrating range data from successive locations of the robot during motion. The efficiency of the proposed approach is illustrated by simulations of a spherical robot in a 3-D room in the presence of moving obstacles and inadequate prelearned partial knowledge of the environment.
Simulation of light transport in scintillators based on 3D characterization of crystal surfaces
Cherry, Simon R.
2013-01-01
In the development of positron emission tomography (PET) detectors, understanding and optimizing scintillator light collection is critical for achieving high performance, particularly when the design incorporates depth-of-interaction (DOI) encoding or time-of-flight information. Monte-Carlo simulations play an important role in guiding research in detector designs and popular software such as GATE now include models of light transport in scintillators. Although current simulation toolkits are able to provide accurate models of perfectly polished surfaces, they do not successfully predict light output for other surface finishes, for example those often used in DOI-encoding detectors. The lack of accuracy of those models mainly originates from a simplified description of rough surfaces as an ensemble of micro-facets determined by the distribution of their normal, typically a Gaussian distribution. The user can specify the standard deviation of this distribution, but this parameter does not provide a full description of the surface reflectance properties. We propose a different approach based on 3D measurements of the surface using atomic force microscopy (AFM). Polished and rough (unpolished) crystals were scanned to compute the surface reflectance properties. The angular distributions of reflectance and reflected rays were computed and stored in look-up tables (LUTs). The LUTs account for the effect of incidence angle and were integrated in a light transport model. Crystals of different sizes were simulated with and without reflector. The simulated maximum light output and the light output as a function of DOI showed very good agreement with experimental characterization of the crystals, indicating that our approach provides an accurate model of polished and rough surfaces and could be used to predict light collection in scintillators. This model is based on a true 3D representation of the surface, makes no assumption about the surface and provides insight on the
NASA Astrophysics Data System (ADS)
Oh, J.; Jiang, X.; Waliser, D. E.; Moncrieff, M. W.; Johnson, R. H.
2013-12-01
As one of the most prominent tropical atmospheric variability modes, the Madden-Julian Oscillation (MJO) exerts profound influences on global weather and climate, and serves as a critical predictability source for extend-range forecast. While credible representation of the MJO still represents a great challenge for current general circulation models (GCMs), previous studies on the vertical structure of the MJO have largely focused on collective impacts from multi-scale convective systems on thermodynamic properties of the MJO. Most recently, limited observational studies and idealized modeling work suggested that convective momentum transport (CMT) could also play an important role in interpreting the observed MJO features. In this study, the 3D CMT structure associated with the MJO is examined by analyzing model output from three recent high-quality reanalysis systems, including NOAA's Climate Forecast System Reanalysis (CFSR), NASA's Modern Era Retrospective-analysis for Research and Applications (MERRA), and ECMWF-the Year of Tropical Convection (YOTC) reanalysis. Consistent with previous cloud-resolving model study, a well-organized three-layer vertical structure in the CMT associated with the MJO is also discerned based on reanalyses. The result suggests that CMT tends to intensify the MJO circulation, particularly in the lower troposphere. Relative roles of meso-scale systems (MCS) and synoptic waves in contributing the total CMT profiles of the MJO will also be explored. Differences in CMT profiles in these several reanalysis models will be discussed.
Crashworthiness analysis using advanced material models in DYNA3D
Logan, R.W.; Burger, M.J.; McMichael, L.D.; Parkinson, R.D.
1993-10-22
As part of an electric vehicle consortium, LLNL and Kaiser Aluminum are conducting experimental and numerical studies on crashworthy aluminum spaceframe designs. They have jointly explored the effect of heat treat on crush behavior and duplicated the experimental behavior with finite-element simulations. The major technical contributions to the state of the art in numerical simulation arise from the development and use of advanced material model descriptions for LLNL`s DYNA3D code. Constitutive model enhancements in both flow and failure have been employed for conventional materials such as low-carbon steels, and also for lighter weight materials such as aluminum and fiber composites being considered for future vehicles. The constitutive model enhancements are developed as extensions from LLNL`s work in anisotropic flow and multiaxial failure modeling. Analysis quality as a function of level of simplification of material behavior and mesh is explored, as well as the penalty in computation cost that must be paid for using more complex models and meshes. The lightweight material modeling technology is being used at the vehicle component level to explore the safety implications of small neighborhood electric vehicles manufactured almost exclusively from these materials.
3D Printed Molecules and Extended Solid Models for Teaching Symmetry and Point Groups
ERIC Educational Resources Information Center
Scalfani, Vincent F.; Vaid, Thomas P.
2014-01-01
Tangible models help students and researchers visualize chemical structures in three dimensions (3D). 3D printing offers a unique and straightforward approach to fabricate plastic 3D models of molecules and extended solids. In this article, we prepared a series of digital 3D design files of molecular structures that will be useful for teaching…
Energy flow in passive and active 3D cochlear model
Wang, Yanli; Steele, Charles; Puria, Sunil
2015-12-31
Energy flow in the cochlea is an important characteristic of the cochlear traveling wave, and many investigators, such as von Békésy and Lighthill, have discussed this phenomenon. Particularly after the discovery of the motility of the outer hair cells (OHCs), the nature of the power gain of the cochlea has been a fundamental research question. In the present work, direct three-dimensional (3D) calculations of the power on cross sections of the cochlea and on the basilar membrane are performed based on a box model of the mouse cochlea. The distributions of the fluid pressure and fluid velocity in the scala vestibuli are presented. The power output from the OHCs and the power loss due to fluid viscous damping are calculated along the length of the cochlea. This work provides a basis for theoretical calculations of the power gain of the OHCs from mechanical considerations.
Energy flow in passive and active 3D cochlear model
NASA Astrophysics Data System (ADS)
Wang, Yanli; Puria, Sunil; Steele, Charles
2015-12-01
Energy flow in the cochlea is an important characteristic of the cochlear traveling wave, and many investigators, such as von Békésy and Lighthill, have discussed this phenomenon. Particularly after the discovery of the motility of the outer hair cells (OHCs), the nature of the power gain of the cochlea has been a fundamental research question. In the present work, direct three-dimensional (3D) calculations of the power on cross sections of the cochlea and on the basilar membrane are performed based on a box model of the mouse cochlea. The distributions of the fluid pressure and fluid velocity in the scala vestibuli are presented. The power output from the OHCs and the power loss due to fluid viscous damping are calculated along the length of the cochlea. This work provides a basis for theoretical calculations of the power gain of the OHCs from mechanical considerations.
3D Model of the San Emidio Geothermal Area
James E. Faulds
2013-12-31
The San Emidio geothermal system is characterized by a left-step in a west-dipping normal fault system that bounds the western side of the Lake Range. The 3D geologic model consists of 5 geologic units and 55 faults. Overlying Jurrassic-Triassic metasedimentary basement is a ~500 m-1000 m thick section of the Miocene lower Pyramid sequence, pre- syn-extensional Quaternary sedimentary rocks and post-extensional Quaternary rocks. 15-30º eastward dip of the stratigraphy is controlled by the predominant west-dipping fault set. Both geothermal production and injection are concentrated north of the step over in an area of closely spaced west dipping normal faults.
3D lithography modeling for ground rule development
NASA Astrophysics Data System (ADS)
Sarma, Chandra; Bailey, Todd; Lyons, Adam; Shao, Dongbing
2011-04-01
The ability to incorporate the effect of patterned underlayers in a 3-dimensional physical resist model that truly mimics the process on real wafers could be used to formulate robust ground rules for design. We have shown as an example block level simulations, where the resist critical dimension is determined by the presence of STI (shallow trench isolation) and/or patterned gate level underneath & their relative spacing, as confirmed on wafer. We will demonstrate how the results of such study could be used for creating ground rules which are truly dependent on the interaction between the current layer resist & the patterned layers underneath. We have also developed a new way to visualize lithographic process variations in 3-D space that is useful for simulation analysis that can prove very helpful in ground rule development and process optimization. Such visualization capability in the dataprep flow to flag issues or dispose critical structures increases speed and efficiency in the mask tapeout process.
Massive fermion model in 3d and higher spin currents
NASA Astrophysics Data System (ADS)
Bonora, L.; Cvitan, M.; Prester, P. Dominis; de Souza, B. Lima; Smolić, I.
2016-05-01
We analyze the 3d free massive fermion theory coupled to external sources. The presence of a mass explicitly breaks parity invariance. We calculate two- and three-point functions of a gauge current and the energy momentum tensor and, for instance, obtain the well-known result that in the IR limit (but also in the UV one) we reconstruct the relevant CS action. We then couple the model to higher spin currents and explicitly work out the spin 3 case. In the UV limit we obtain an effective action which was proposed many years ago as a possible generalization of spin 3 CS action. In the IR limit we derive a different higher spin action. This analysis can evidently be generalized to higher spins. We also discuss the conservation and properties of the correlators we obtain in the intermediate steps of our derivation.
3D Model of the Neal Hot Springs Geothermal Area
Faulds, James E.
2013-12-31
The Neal Hot Springs geothermal system lies in a left-step in a north-striking, west-dipping normal fault system, consisting of the Neal Fault to the south and the Sugarloaf Butte Fault to the north (Edwards, 2013). The Neal Hot Springs 3D geologic model consists of 104 faults and 13 stratigraphic units. The stratigraphy is sub-horizontal to dipping <10 degrees and there is no predominant dip-direction. Geothermal production is exclusively from the Neal Fault south of, and within the step-over, while geothermal injection is into both the Neal Fault to the south of the step-over and faults within the step-over.
3D Model of the Tuscarora Geothermal Area
Faulds, James E.
2013-12-31
The Tuscarora geothermal system sits within a ~15 km wide left-step in a major west-dipping range-bounding normal fault system. The step over is defined by the Independence Mountains fault zone and the Bull Runs Mountains fault zone which overlap along strike. Strain is transferred between these major fault segments via and array of northerly striking normal faults with offsets of 10s to 100s of meters and strike lengths of less than 5 km. These faults within the step over are one to two orders of magnitude smaller than the range-bounding fault zones between which they reside. Faults within the broad step define an anticlinal accommodation zone wherein east-dipping faults mainly occupy western half of the accommodation zone and west-dipping faults lie in the eastern half of the accommodation zone. The 3D model of Tuscarora encompasses 70 small-offset normal faults that define the accommodation zone and a portion of the Independence Mountains fault zone, which dips beneath the geothermal field. The geothermal system resides in the axial part of the accommodation, straddling the two fault dip domains. The Tuscarora 3D geologic model consists of 10 stratigraphic units. Unconsolidated Quaternary alluvium has eroded down into bedrock units, the youngest and stratigraphically highest bedrock units are middle Miocene rhyolite and dacite flows regionally correlated with the Jarbidge Rhyolite and modeled with uniform cumulative thickness of ~350 m. Underlying these lava flows are Eocene volcanic rocks of the Big Cottonwood Canyon caldera. These units are modeled as intracaldera deposits, including domes, flows, and thick ash deposits that change in thickness and locally pinch out. The Paleozoic basement of consists metasedimenary and metavolcanic rocks, dominated by argillite, siltstone, limestone, quartzite, and metabasalt of the Schoonover and Snow Canyon Formations. Paleozoic formations are lumped in a single basement unit in the model. Fault blocks in the eastern
A 3D parallel model of Ganymede's exosphere
NASA Astrophysics Data System (ADS)
Leclercq, Ludivine; Turc, Lucile; François, Leblanc; Ronan, Modolo
2013-04-01
Ganymede is a unique object : it is the biggest moon of our solar system, and the only satellite which has its own intrinsic magnetic field. Its surface is covered by water ice and by regolith. Some previous observations suggest that below its surface may exist an ocean of liquid water. The atmosphere of the planet is poorly known but should be composed essentially of water, hydrogen and oxygen (Marconi et al., Icarus, 2007). These atmospheric particles mainly originate from the surface thanks to sublimation of water-ice and sputtering, a process driven by the magnetospheric Jovian particles impacting Ganymede surface and leading to ejection of atoms and molecules into Ganymede atmosphere. We developed a model of Ganymede's atmosphere based on a 3D Monte Carlo description of the fate of the ejected particles from the surface. This model has been parallelized allowing a much better statistical, spatial and temporal description of Ganymede's environment. This model includes the main sources of the neutral atmosphere and is able to calculate all its characteristics. It was successfully compared to the few known observations as well as to previous modeling. In this presentation, we will present the main characteristics of this model and what it tells us on Ganymede's atmosphere, in terms of spatial structure, composition, temporal variability and relations with both magnetosphere and surface.
A Self-Consistent Beam Loaded Travelling Wave Accelerator Model for use in TRACE-3D
NASA Astrophysics Data System (ADS)
Lampel, M. C.
1997-05-01
An optics model of a constant gradient traveling wave (CGTW) accelerator structure has been implemented for TRACE-3D. TRACE-3D is an envelope code including space charge that is used to model bunched beams in magnetic transport systems and radio frequency (rf) accelerators when the effects of beam current might be significant. The new matrix model has been developed to allow incorporation of particle beam loading (current) effects on the accelerator gradient and the accelerator structure's beam focusing properties in a self-consistent manner. The beam loaded electric field for a CGTW accelerator structure is constant for only a particular design current (e.g., 0 current), otherwise it can be written as a function of accelerator attenuation and axial position along the structure. The variation of the electric field through the structure has been taken into account in the new model. CGTW structures differ substantially in focusing properties and beam loading properties from standing wave structures. Examples will be presented using the new TW model, propagating electron beams with different currents through the Stanford Linear Accelerator Center's 3 m structure. The results will be compared to the zero current TW structure model in TRANSPORT and the Tank model (a standing wave structure model) in TRACE-3D. A computer demonstration of the code with the new element will also be presented.
Modeling Electric Current Flow in 3D Fractured Media
NASA Astrophysics Data System (ADS)
Demirel, S.; Roubinet, D.; Irving, J.
2014-12-01
The study of fractured rocks is extremely important in a variety of research fields and applications such as hydrogeology, hydrocarbon extraction and long-term storage of toxic waste. As fractures are highly conductive structures in comparison to the surrounding rock, their presence can be either an advantage or a drawback. For hydrocarbon extraction, fractures allow for quick and easy access to the resource whereas for toxic waste storage their presence increases the risk of leakage and migration of pollutants. In both cases, the identification of fracture network characteristics is an essential step. Recently, we have developed an approach for modeling electric current flow in 2D fractured media. This approach is based on a discrete-dual-porosity model where fractures are represented explicitly, the matrix is coarsely discretized into blocks, and current flow exchange between the fractures and matrix is analytically evaluated at the fracture-scale and integrated at the block-scale [1]. Although this approach has shown much promise and has proven its efficiency for 2D simulations, its extension to 3D remains to be addressed. To this end, we assume that fractures can be represented as two-dimensional finite planes embedded in the surrounding matrix, and we express analytically the distribution of electric potential at the fracture scale. This fracture-scale expression takes into account the electric-current-flow exchange with the surrounding matrix and flow conservation is enforced at the fracture intersections. The fracture-matrix exchange is then integrated at the matrix-block scale where the electric current flow conservation at the block boundaries is formulated with a modified finite volume method. With the objective of providing a low-computational-cost modeling approach adapted to 3D simulations in fractured media, our model is (i) validated and compared to existing modeling approaches and, (ii) used to evaluate the impact of the presence of fractures on
A hybrid-3D hillslope hydrological model for use in Earth system models
NASA Astrophysics Data System (ADS)
Hazenberg, P.; Fang, Y.; Broxton, P.; Gochis, D.; Niu, G.-Y.; Pelletier, J. D.; Troch, P. A.; Zeng, X.
2015-10-01
Hillslope-scale rainfall-runoff processes leading to a fast catchment response are not explicitly included in land surface models (LSMs) for use in earth system models (ESMs) due to computational constraints. This study presents a hybrid-3D hillslope hydrological model (h3D) that couples a 1-D vertical soil column model with a lateral pseudo-2D saturated zone and overland flow model for use in ESMs. By representing vertical and lateral responses separately at different spatial resolutions, h3D is computationally efficient. The h3D model was first tested for three different hillslope planforms (uniform, convergent and divergent). We then compared h3D (with single and multiple soil columns) with a complex physically based 3-D model and a simple 1-D soil moisture model coupled with an unconfined aquifer (as typically used in LSMs). It is found that simulations obtained by the simple 1-D model vary considerably from the complex 3-D model and are not able to represent hillslope-scale variations in the lateral flow response. In contrast, the single soil column h3D model shows a much better performance and saves computational time by 2-3 orders of magnitude compared with the complex 3-D model. When multiple vertical soil columns are implemented, the resulting hydrological responses (soil moisture, water table depth, and base flow along the hillslope) from h3D are nearly identical to those predicted by the complex 3-D model, but still saves computational time. As such, the computational efficiency of the h3D model provides a valuable and promising approach to incorporating hillslope-scale hydrological processes into continental and global-scale ESMs.
Reactor Dosimetry Applications Using RAPTOR-M3G:. a New Parallel 3-D Radiation Transport Code
NASA Astrophysics Data System (ADS)
Longoni, Gianluca; Anderson, Stanwood L.
2009-08-01
The numerical solution of the Linearized Boltzmann Equation (LBE) via the Discrete Ordinates method (SN) requires extensive computational resources for large 3-D neutron and gamma transport applications due to the concurrent discretization of the angular, spatial, and energy domains. This paper will discuss the development RAPTOR-M3G (RApid Parallel Transport Of Radiation - Multiple 3D Geometries), a new 3-D parallel radiation transport code, and its application to the calculation of ex-vessel neutron dosimetry responses in the cavity of a commercial 2-loop Pressurized Water Reactor (PWR). RAPTOR-M3G is based domain decomposition algorithms, where the spatial and angular domains are allocated and processed on multi-processor computer architectures. As compared to traditional single-processor applications, this approach reduces the computational load as well as the memory requirement per processor, yielding an efficient solution methodology for large 3-D problems. Measured neutron dosimetry responses in the reactor cavity air gap will be compared to the RAPTOR-M3G predictions. This paper is organized as follows: Section 1 discusses the RAPTOR-M3G methodology; Section 2 describes the 2-loop PWR model and the numerical results obtained. Section 3 addresses the parallel performance of the code, and Section 4 concludes this paper with final remarks and future work.
Efficient sensitivity computations in 3D air quality models
NASA Astrophysics Data System (ADS)
Kioutsioukis, Ioannis; Melas, Dimitrios; Zerefos, Christos; Ziomas, Ioannis
2005-04-01
The prediction of ground level ozone for air quality monitoring and assessment is simulated through an integrated system of gridded models (meteorological, photochemical), where the atmosphere is represented with a three-dimensional grid that may include thousands of grid cells. The continuity equation solved by the Photochemical Air Quality Model (PAQM) reproduces the atmospheric processes (dynamical, physical, chemical and radiative), such as moving and mixing air parcels from one grid cell to another, calculating chemical reactions, injecting new emissions. The whole modeling procedure includes several sources of uncertainty, especially in the large data sets that describe the status of the domain (boundary conditions, emissions, chemical reaction rates and several others). The robustness of the photochemical simulation is addressed in this work through the deterministic approach of sensitivity analysis. The automatic differentiation tool ADIFOR is applied on the 3D PAQM CAMx and augments its Fortran 77 code by introducing new lines of code that additionally calculate, in only one run, the gradient of the solution vector with respect to its input parameters. The applicability of the approach is evaluated through a sensitivity study of the modeled concentrations to perturbations at the boundary conditions and the emissions, for three essentially dissimilar European Metropolises of the Auto-Oil II programme (Athens, Milan, and London).
Indoor Modelling Benchmark for 3D Geometry Extraction
NASA Astrophysics Data System (ADS)
Thomson, C.; Boehm, J.
2014-06-01
A combination of faster, cheaper and more accurate hardware, more sophisticated software, and greater industry acceptance have all laid the foundations for an increased desire for accurate 3D parametric models of buildings. Pointclouds are the data source of choice currently with static terrestrial laser scanning the predominant tool for large, dense volume measurement. The current importance of pointclouds as the primary source of real world representation is endorsed by CAD software vendor acquisitions of pointcloud engines in 2011. Both the capture and modelling of indoor environments require great effort in time by the operator (and therefore cost). Automation is seen as a way to aid this by reducing the workload of the user and some commercial packages have appeared that provide automation to some degree. In the data capture phase, advances in indoor mobile mapping systems are speeding up the process, albeit currently with a reduction in accuracy. As a result this paper presents freely accessible pointcloud datasets of two typical areas of a building each captured with two different capture methods and each with an accurate wholly manually created model. These datasets are provided as a benchmark for the research community to gauge the performance and improvements of various techniques for indoor geometry extraction. With this in mind, non-proprietary, interoperable formats are provided such as E57 for the scans and IFC for the reference model. The datasets can be found at: http://indoor-bench.github.io/indoor-bench.
3-D Eutrophication Modeling for Lake Simcoe, Canada
NASA Astrophysics Data System (ADS)
Lu, Q.; Duckett, F.; Nairn, R.; Brunton, A.
2006-12-01
The Lake Simcoe Region Conservation Authority (LSRCA) and the Province of Ontario are undertaking a series of studies to facilitate management of the pressures of population growth in the Lake Simcoe watershed. With rapid population growth and urban development comes additional land clearing, storm water runoff and the discharge of treated sewage, all of which are sources of increased phosphorus loading to Lake Simcoe. Depressed oxygen levels were linked to phosphorous enrichment of the lake, with the resultant stimulation of algal growth in the sunlit upper waters of the lake, and its subsequent senescence and settling into the hypolimnion where bacterial decomposition consumes oxygen from the stratified waters. This poster describes a 3-D hydrodynamic, thermal and water quality model of Lake Simcoe developed using the Danish Hydraulics Institute (DHI) MIKE3 model. The hydrodynamic module includes wind-driven circulation, temperature variation, development of the thermocline and thermal stratification, and hydraulic forcing from inflowing tributaries. This is linked to the water quality module which simulates the eutrophication processes in the response of the lake to loadings of phosphorus, such as algal growth, the growth of aquatic plants and subsequent oxygen consumption. The model has been calibrated against Acoustic Doppler Current Profiler velocity data, plus measured temperature and water quality data at MOE stations in the lake and water intakes. The model is an important assessment tool for the management of the lake and its watersheds, allowing assessment of the impacts of the urban growth and land use change on the water quality in Lake Simcoe.
Planetary subsurface investigation by 3D visualization model .
NASA Astrophysics Data System (ADS)
Seu, R.; Catallo, C.; Tragni, M.; Abbattista, C.; Cinquepalmi, L.
Subsurface data analysis and visualization represents one of the main aspect in Planetary Observation (i.e. search for water or geological characterization). The data are collected by subsurface sounding radars as instruments on-board of deep space missions. These data are generally represented as 2D radargrams in the perspective of space track and z axes (perpendicular to the subsurface) but without direct correlation to other data acquisition or knowledge on the planet . In many case there are plenty of data from other sensors of the same mission, or other ones, with high continuity in time and in space and specially around the scientific sites of interest (i.e. candidate landing areas or particular scientific interesting sites). The 2D perspective is good to analyse single acquisitions and to perform detailed analysis on the returned echo but are quite useless to compare very large dataset as now are available on many planets and moons of solar system. The best way is to approach the analysis on 3D visualization model generated from the entire stack of data. First of all this approach allows to navigate the subsurface in all directions and analyses different sections and slices or moreover navigate the iso-surfaces respect to a value (or interval). The last one allows to isolate one or more iso-surfaces and remove, in the visualization mode, other data not interesting for the analysis; finally it helps to individuate the underground 3D bodies. Other aspect is the needs to link the on-ground data, as imaging, to the underground one by geographical and context field of view.
Accurate, low-cost 3D-models of gullies
NASA Astrophysics Data System (ADS)
Onnen, Nils; Gronz, Oliver; Ries, Johannes B.; Brings, Christine
2015-04-01
Soil erosion is a widespread problem in arid and semi-arid areas. The most severe form is the gully erosion. They often cut into agricultural farmland and can make a certain area completely unproductive. To understand the development and processes inside and around gullies, we calculated detailed 3D-models of gullies in the Souss Valley in South Morocco. Near Taroudant, we had four study areas with five gullies different in size, volume and activity. By using a Canon HF G30 Camcorder, we made varying series of Full HD videos with 25fps. Afterwards, we used the method Structure from Motion (SfM) to create the models. To generate accurate models maintaining feasible runtimes, it is necessary to select around 1500-1700 images from the video, while the overlap of neighboring images should be at least 80%. In addition, it is very important to avoid selecting photos that are blurry or out of focus. Nearby pixels of a blurry image tend to have similar color values. That is why we used a MATLAB script to compare the derivatives of the images. The higher the sum of the derivative, the sharper an image of similar objects. MATLAB subdivides the video into image intervals. From each interval, the image with the highest sum is selected. E.g.: 20min. video at 25fps equals 30.000 single images. The program now inspects the first 20 images, saves the sharpest and moves on to the next 20 images etc. Using this algorithm, we selected 1500 images for our modeling. With VisualSFM, we calculated features and the matches between all images and produced a point cloud. Then, MeshLab has been used to build a surface out of it using the Poisson surface reconstruction approach. Afterwards we are able to calculate the size and the volume of the gullies. It is also possible to determine soil erosion rates, if we compare the data with old recordings. The final step would be the combination of the terrestrial data with the data from our aerial photography. So far, the method works well and we
3D numerical modeling of India-Asia-like collision
NASA Astrophysics Data System (ADS)
-Erika Püsök, Adina; Kaus, Boris; Popov, Anton
2013-04-01
above a strong mantle lithosphere - the jelly sandwich model (Burov and Watts, 2006). 3D models are thus needed to investigate these hypotheses. However, fully 3D models of the dynamics of continent collision zones have only been developed very recently, and presently most research groups have relied on certain explicit assumptions for their codes. Here, we employ the parallel 3D code LaMEM (Lithosphere and Mantle Evolution Model), with a finite difference staggered grid solver, which is capable of simulating lithospheric deformation while simultaneously taking mantle flow and a free surface into account. We here report on first lithospheric and upper-mantle scale simulations in which the Indian lithosphere is indented into Asia. Acknowledgements. Funding was provided by the European Research Council under the European Community's Seventh Framework Program (FP7/2007-2013) / ERC Grant agreement #258830. Numerical computations have been performed on JUQUEEN of the Jülich high-performance computing center. • Beaumont, C., Jamieson, R.A., Nguyen, M.H., Medvedev, S.E., 2004. Crustal channel flows: 1. Numerical models with applications to the tectonics of the Himalayan-Tibetan orogeny. J. Geophys. Res. 109, B06406. • Burov, E. & Watts, W.S., 2006. The long-term strength of continental lithosphere: "jelly sandwich" or "crème brûlée"?. GSA Today, 16, doi: 10.1130/1052-5173(2006)1016<1134:TLTSOC>1132.1130.CO;1132. • England P., Houseman, G., 1986. Finite strain calculations of continental deformation. 2. Comparison with the India-Asia collision zone. J. Geophys. Res.- Solid Earth and Planets 91 (B3), 3664-3676. • Jackson, J., 2002. Strength of the continental lithosphere: time to abandon the jelly sandwich?. GSA Today, September, 4-10. • Lechmann, S.M., May, D.A., Kaus, B.J.P., Schmalholz, S.M., 2011. Comparing thin-sheet models with 3D multilayer models for continental collision. Geophy. Int. J. doi: 10.1111/j.1365-246X.2011.05164.x • Royden, L.H., Burchfiel, B
NASA Astrophysics Data System (ADS)
Druzgalski, Clara; Mani, Ali
2014-11-01
We have investigated the transport dynamics of an electrokinetic instability that occurs when ions are driven from bulk fluids to ion-selective membranes due to externally applied electric fields. This phenomenon is relevant to a wide range of electrochemical applications including electrodialysis for fresh water production. Using data from our 3D DNS, we show how electroconvective instability, arising from concentration polarization, results in a chaotic flow that significantly alters the net ion transport rate across the membrane surface. The 3D DNS results, which fully resolve the spatiotemporal scales including the electric double layers, enable visualization of instantaneous snapshots of current density directly on the membrane surface, as well as analysis of transport statistics such as concentration variance and fluctuating advective fluxes. Furthermore, we present a full spectral analysis revealing broadband spectra in both concentration and flow fields and deduce the key parameter controlling the range of contributing scales.
3D Printing of Molecular Potential Energy Surface Models
ERIC Educational Resources Information Center
Lolur, Phalgun; Dawes, Richard
2014-01-01
Additive manufacturing, commonly known as 3D printing, is gaining popularity in a variety of applications and has recently become routinely available. Today, 3D printing services are not only found in engineering design labs and through online companies, but also in university libraries offering student access. In addition, affordable options for…
3D-Digital soil property mapping by geoadditive models
NASA Astrophysics Data System (ADS)
Papritz, Andreas
2016-04-01
In many digital soil mapping (DSM) applications, soil properties must be predicted not only for a single but for multiple soil depth intervals. In the GlobalSoilMap project, as an example, predictions are computed for the 0-5 cm, 5-15 cm, 15-30 cm, 30-60 cm, 60-100 cm, 100-200 cm depth intervals (Arrouays et al., 2014). Legacy soil data are often used for DSM. It is common for such datasets that soil properties were measured for soil horizons or for layers at varying soil depth and with non-constant thickness (support). This poses problems for DSM: One strategy is to harmonize the soil data to common depth prior to the analyses (e.g. Bishop et al., 1999) and conduct the statistical analyses for each depth interval independently. The disadvantage of this approach is that the predictions for different depths are computed independently from each other so that the predicted depth profiles may be unrealistic. Furthermore, the error induced by the harmonization to common depth is ignored in this approach (Orton et al. 2016). A better strategy is therefore to process all soil data jointly without prior harmonization by a 3D-analysis that takes soil depth and geographical position explicitly into account. Usually, the non-constant support of the data is then ignored, but Orton et al. (2016) presented recently a geostatistical approach that accounts for non-constant support of soil data and relies on restricted maximum likelihood estimation (REML) of a linear geostatistical model with a separable, heteroscedastic, zonal anisotropic auto-covariance function and area-to-point kriging (Kyriakidis, 2004.) Although this model is theoretically coherent and elegant, estimating its many parameters by REML and selecting covariates for the spatial mean function is a formidable task. A simpler approach might be to use geoadditive models (Kammann and Wand, 2003; Wand, 2003) for 3D-analyses of soil data. geoAM extend the scope of the linear model with spatially correlated errors to
3D-Digital soil property mapping by geoadditive models
NASA Astrophysics Data System (ADS)
Papritz, Andreas
2016-04-01
In many digital soil mapping (DSM) applications, soil properties must be predicted not only for a single but for multiple soil depth intervals. In the GlobalSoilMap project, as an example, predictions are computed for the 0-5 cm, 5-15 cm, 15-30 cm, 30-60 cm, 60-100 cm, 100-200 cm depth intervals (Arrouays et al., 2014). Legacy soil data are often used for DSM. It is common for such datasets that soil properties were measured for soil horizons or for layers at varying soil depth and with non-constant thickness (support). This poses problems for DSM: One strategy is to harmonize the soil data to common depth prior to the analyses (e.g. Bishop et al., 1999) and conduct the statistical analyses for each depth interval independently. The disadvantage of this approach is that the predictions for different depths are computed independently from each other so that the predicted depth profiles may be unrealistic. Furthermore, the error induced by the harmonization to common depth is ignored in this approach (Orton et al. 2016). A better strategy is therefore to process all soil data jointly without prior harmonization by a 3D-analysis that takes soil depth and geographical position explicitly into account. Usually, the non-constant support of the data is then ignored, but Orton et al. (2016) presented recently a geostatistical approach that accounts for non-constant support of soil data and relies on restricted maximum likelihood estimation (REML) of a linear geostatistical model with a separable, heteroscedastic, zonal anisotropic auto-covariance function and area-to-point kriging (Kyriakidis, 2004.) Although this model is theoretically coherent and elegant, estimating its many parameters by REML and selecting covariates for the spatial mean function is a formidable task. A simpler approach might be to use geoadditive models (Kammann and Wand, 2003; Wand, 2003) for 3D-analyses of soil data. geoAM extend the scope of the linear model with spatially correlated errors to
3D Finite Difference Modelling of Basaltic Region
NASA Astrophysics Data System (ADS)
Engell-Sørensen, L.
2003-04-01
The main purpose of the work was to generate realistic data to be applied for testing of processing and migration tools for basaltic regions. The project is based on the three - dimensional finite difference code (FD), TIGER, made by Sintef. The FD code was optimized (parallelized) by the author, to run on parallel computers. The parallel code enables us to model large-scale realistic geological models and to apply traditional seismic and micro seismic sources. The parallel code uses multiple processors in order to manipulate subsets of large amounts of data simultaneously. The general anisotropic code uses 21 elastic coefficients. Eight independent coefficients are needed as input parameters for the general TI medium. In the FD code, the elastic wave field computation is implemented by a higher order FD solution to the elastic wave equation and the wave fields are computed on a staggered grid, shifted half a node in one or two directions. The geological model is a gridded basalt model, which covers from 24 km to 37 km of a real shot line in horizontal direction and from the water surface to the depth of 3.5 km. The 2frac {1}{2}D model has been constructed using the compound modeling software from Norsk Hydro. The vertical parameter distribution is obtained from observations in two wells. At The depth of between 1100 m to 1500 m, a basalt horizon covers the whole sub surface layers. We have shown that it is possible to simulate a line survey in realistic (3D) geological models in reasonable time by using high performance computers. The author would like to thank Norsk Hydro, Statoil, GEUS, and SINTEF for very helpful discussions and Parallab for being helpful with the new IBM, p690 Regatta system.
Predicted 3D Model of the Rabies Virus Glycoprotein Trimer.
Fernando, Bastida-González; Yersin, Celaya-Trejo; José, Correa-Basurto; Paola, Zárate-Segura
2016-01-01
The RABVG ectodomain is a homotrimer, and trimers are often called spikes. They are responsible for the attachment of the virus through the interaction with nicotinic acetylcholine receptors, neural cell adhesion molecule (NCAM), and the p75 neurotrophin receptor (p75NTR). This makes them relevant in viral pathogenesis. The antigenic structure differs significantly between the trimers and monomers. Surfaces rich in hydrophobic amino acids are important for trimer stabilization in which the C-terminal of the ectodomain plays an important role; to understand these interactions between the G proteins, a mechanistic study of their functions was performed with a molecular model of G protein in its trimeric form. This verified its 3D conformation. The molecular modeling of G protein was performed by a I-TASSER server and was evaluated via a Rachamandran plot and ERRAT program obtained 84.64% and 89.9% of the residues in the favorable regions and overall quality factor, respectively. The molecular dynamics simulations were carried out on RABVG trimer at 310 K. From these theoretical studies, we retrieved the RMSD values from Cα atoms to assess stability. Preliminary model of G protein of rabies virus stable at 12 ns with molecular dynamics was obtained. PMID:27294109
Predicted 3D Model of the Rabies Virus Glycoprotein Trimer
Fernando, Bastida-González; Yersin, Celaya-Trejo; José, Correa-Basurto; Paola, Zárate-Segura
2016-01-01
The RABVG ectodomain is a homotrimer, and trimers are often called spikes. They are responsible for the attachment of the virus through the interaction with nicotinic acetylcholine receptors, neural cell adhesion molecule (NCAM), and the p75 neurotrophin receptor (p75NTR). This makes them relevant in viral pathogenesis. The antigenic structure differs significantly between the trimers and monomers. Surfaces rich in hydrophobic amino acids are important for trimer stabilization in which the C-terminal of the ectodomain plays an important role; to understand these interactions between the G proteins, a mechanistic study of their functions was performed with a molecular model of G protein in its trimeric form. This verified its 3D conformation. The molecular modeling of G protein was performed by a I-TASSER server and was evaluated via a Rachamandran plot and ERRAT program obtained 84.64% and 89.9% of the residues in the favorable regions and overall quality factor, respectively. The molecular dynamics simulations were carried out on RABVG trimer at 310 K. From these theoretical studies, we retrieved the RMSD values from Cα atoms to assess stability. Preliminary model of G protein of rabies virus stable at 12 ns with molecular dynamics was obtained. PMID:27294109
Collision of continental corner from 3-D numerical modeling
NASA Astrophysics Data System (ADS)
Li, Zhong-Hai; Xu, Zhiqin; Gerya, Taras; Burg, Jean-Pierre
2013-10-01
Continental collision has been extensively investigated with 2-D numerical models assuming infinitely wide plates or insignificant along-strike deformation in the third dimension. However, the corners of natural collision zones normally have structural characteristics that differ from linear parts of mountain belt. We conducted 3-D high-resolution numerical simulations to study the dynamics of a continental corner (lateral continental/oceanic transition zone) during subduction/collision. The results demonstrate different modes between the oceanic subduction side (continuous subduction and retreating trench) and the continental collision side (slab break-off and topography uplift). Slab break-off occurs at a depth (⩽100 km to ˜300 km) that depends on the convergence velocity. The numerical models produce lateral extrusion of the overriding crust from the collisional side to the subduction side, which is also a phenomenon recognized around natural collision of continental corners, for instance around the western corner of the Arabia-Asia collision zone and around the eastern corner of the India-Asia collision zone. Modeling results also indicate that extrusion tectonics may be driven both from above by the topography and gravitational potentials and from below by the trench retreat and asthenospheric mantle return flow, which supports the link between deep mantle dynamics and shallower crustal deformation.
NASA Astrophysics Data System (ADS)
Tegtmeier, W.; Zlatanova, S.; van Oosterom, P. J. M.; Hack, H. R. G. K.
2014-03-01
In infrastructural projects, communication as well as information exchange and (re-)use in and between involved parties is difficult. Mainly this is caused by a lack of information harmonisation. Various specialists are working together on the development of an infrastructural project and all use their own specific software and definitions for various information types. In addition, the lack of and/or differences in the use and definition of thematic semantic information regarding the various information types adds to the problem. Realistic 3D models describing and integrating parts of the earth already exist, but are generally neglecting the subsurface, and especially the aspects of geology and geo-technology. This paper summarises the research towards the extension of an existing integrated semantic information model to include surface as well as subsurface objects and in particular, subsurface geological and geotechnical objects. The major contributions of this research are the definition of geotechnical objects and the mechanism to link them with CityGML, GeoSciML and O&M standard models. The model is called 3D-GEM, short for 3D Geotechnical Extension Model.
NASA Astrophysics Data System (ADS)
Thomas, Justin W.
2006-12-01
The Numerical Nuclear Reactor (NNR) is a code suite that is being developed to provide high-fidelity multi-physics capability for the analysis of light water nuclear reactors. The focus of the work here is to extend the capability of the NNR by incorporation of the neutronics module, DeCART, for Boiling Water Reactor (BWR) applications. The DeCART code has been coupled to the NNR fluid mechanics and heat transfer module STAR-CD for light water reactor applications. The coupling has been accomplished via an interface program, which is responsible for mapping the STAR-CD and DeCART meshes, managing communication, and monitoring convergence. DeCART obtains the solution of the 3-D Boltzmann transport equation by performing a series of 2-D modular ray tracing-based method of characteristics problems that are coupled within the framework of 3-D coarse-mesh finite difference. The relatively complex geometry and increased axial heterogeneity found in BWRs are beyond the modeling capability of the original version of DeCART. In this work, DeCART is extended in three primary areas. First, the geometric capability is generalized by extending the modular ray tracing scheme and permitting an unstructured mesh in the global finite difference kernel. Second, numerical instabilities, which arose as a result of the severe axial heterogeneity found in BWR cores, have been resolved. Third, an advanced nodal method has been implemented to improve the accuracy of the axial flux distribution. In this semi-analytic nodal method, the analytic solution to the transverse-integrated neutron diffusion equation is obtained, where the nonhomogeneous neutron source was first approximated by a quartic polynomial. The successful completion of these three tasks has allowed the application of the coupled DeCART/STAR-CD code to practical BWR problems.
NASA Astrophysics Data System (ADS)
Jha, Sanjeev Kumar; Comunian, Alessandro; Mariethoz, Gregoire; Kelly, Bryce F. J.
2014-10-01
We develop a stochastic approach to construct channelized 3-D geological models constrained to borehole measurements as well as geological interpretation. The methodology is based on simple 2-D geologist-provided sketches of fluvial depositional elements, which are extruded in the 3rd dimension. Multiple-point geostatistics (MPS) is used to impair horizontal variability to the structures by introducing geometrical transformation parameters. The sketches provided by the geologist are used as elementary training images, whose statistical information is expanded through randomized transformations. We demonstrate the applicability of the approach by applying it to modeling a fluvial valley filling sequence in the Maules Creek catchment, Australia. The facies models are constrained to borehole logs, spatial information borrowed from an analogue and local orientations derived from the present-day stream networks. The connectivity in the 3-D facies models is evaluated using statistical measures and transport simulations. Comparison with a statistically equivalent variogram-based model shows that our approach is more suited for building 3-D facies models that contain structures specific to the channelized environment and which have a significant influence on the transport processes.
Real-time forecasting of Hong Kong beach water quality by 3D deterministic model.
Chan, S N; Thoe, W; Lee, J H W
2013-03-15
Bacterial level (e.g. Escherichia coli) is generally adopted as the key indicator of beach water quality due to its high correlation with swimming associated illnesses. A 3D deterministic hydrodynamic model is developed to provide daily water quality forecasting for eight marine beaches in Tsuen Wan, which are only about 8 km from the Harbour Area Treatment Scheme (HATS) outfall discharging 1.4 million m(3)/d of partially-treated sewage. The fate and transport of the HATS effluent and its impact on the E. coli level at nearby beaches are studied. The model features the seamless coupling of near field jet mixing and the far field transport and dispersion of wastewater discharge from submarine outfalls, and a spatial-temporal dependent E. coli decay rate formulation specifically developed for sub-tropical Hong Kong waters. The model prediction of beach water quality has been extensively validated against field data both before and after disinfection of the HATS effluent. Compared with daily beach E. coli data during August-November 2011, the model achieves an overall accuracy of 81-91% in forecasting compliance/exceedance of beach water quality standard. The 3D deterministic model has been most valuable in the interpretation of the complex variation of beach water quality which depends on tidal level, solar radiation and other hydro-meteorological factors. The model can also be used in optimization of disinfection dosage and in emergency response situations. PMID:23337883
3D Model Segmentation and Representation with Implicit Polynomials
NASA Astrophysics Data System (ADS)
Zheng, Bo; Takamatsu, Jun; Ikeuchi, Katsushi
When large-scale and complex 3D objects are obtained by range finders, it is often necessary to represent them by algebraic surfaces for such purposes as data compression, multi-resolution, noise elimination, and 3D recognition. Representing the 3D data with algebraic surfaces of an implicit polynomial (IP) has proved to offer the advantages that IP representation is capable of encoding geometric properties easily with desired smoothness, few parameters, algebraic/geometric invariants, and robustness to noise and missing data. Unfortunately, generating a high-degree IP surface for a whole complex 3D shape is impossible because of high computational cost and numerical instability. In this paper we propose a 3D segmentation method based on a cut-and-merge approach. Two cutting procedures adopt low-degree IPs to divide and fit the surface segments simultaneously, while avoiding generating high-curved segments. A merging procedure merges the similar adjacent segments to avoid over-segmentation. To prove the effectiveness of this segmentation method, we open up some new vistas for 3D applications such as 3D matching, recognition, and registration.
Object-oriented urban 3D spatial data model organization method
NASA Astrophysics Data System (ADS)
Li, Jing-wen; Li, Wen-qing; Lv, Nan; Su, Tao
2015-12-01
This paper combined the 3d data model with object-oriented organization method, put forward the model of 3d data based on object-oriented method, implemented the city 3d model to quickly build logical semantic expression and model, solved the city 3d spatial information representation problem of the same location with multiple property and the same property with multiple locations, designed the space object structure of point, line, polygon, body for city of 3d spatial database, and provided a new thought and method for the city 3d GIS model and organization management.
A 3D world model builder with a mobile robot
Zhang, Z.; Faugeras, O. )
1992-08-01
This article describes a system to incrementally build a world model with a mobile robot in an unknown environment. The model is, for the moment, segment based. A trinocular stereo system is used to build a local map about the environment. A global map is obtained by integrating a sequence of stereo frames taken when the robot navigates in the environment. The emphasis of this article is on the representation of the uncertainty of 3D segments from stereo and on the integration of segments from multiple views. The proposed representation is simple and very convenient to characterize the uncertainty of segment. A Kalman filter is used to merge matched line segments. An important characteristic of this integration strategy is that a segment observed by the stereo system corresponds only to one part of the segment in space, so the union of the different observations gives a better estimate on the segment in space. The authors have succeeded in integrating 35 stereo frames taken in their robot room.
Pros and Cons of ID vs. 3D Modeling
NASA Technical Reports Server (NTRS)
Klimchuk, James A.
2012-01-01
Advances in computing capability have led to tremendous improvements in 3D modeling. Entire active regions are being simulated in what might be described as a first principles way, in which plasma heating is treated self consistently rather than through the specification of heating functions. There are limitations to this approach, however, as actual heating mechanisms on the Sun involve spatial scales orders of magnitude smaller than what these simulations can resolve. Other simulations begin to resolve these scales, but they only treat a tiny volume and do not include the all important coupling with larger scales or with other parts of the atmosphere, and so cannot be readily compared with observations. Finally, ID hydrodynamic models capture the field-aligned evolution of the plasma extremely well and are ideally suited for data comparison, but they treat the heating in a totally ad hoc manner. All of these approaches have important contributions to make, but we must be aware of their limitations. I will highlight some of the strengths. and weaknesses of each.
Flexible building primitives for 3D building modeling
NASA Astrophysics Data System (ADS)
Xiong, B.; Jancosek, M.; Oude Elberink, S.; Vosselman, G.
2015-03-01
3D building models, being the main part of a digital city scene, are essential to all applications related to human activities in urban environments. The development of range sensors and Multi-View Stereo (MVS) technology facilitates our ability to automatically reconstruct level of details 2 (LoD2) models of buildings. However, because of the high complexity of building structures, no fully automatic system is currently available for producing building models. In order to simplify the problem, a lot of research focuses only on particular buildings shapes, and relatively simple ones. In this paper, we analyze the property of topology graphs of object surfaces, and find that roof topology graphs have three basic elements: loose nodes, loose edges, and minimum cycles. These elements have interesting physical meanings: a loose node is a building with one roof face; a loose edge is a ridge line between two roof faces whose end points are not defined by a third roof face; and a minimum cycle represents a roof corner of a building. Building primitives, which introduce building shape knowledge, are defined according to these three basic elements. Then all buildings can be represented by combining such building primitives. The building parts are searched according to the predefined building primitives, reconstructed independently, and grouped into a complete building model in a CSG-style. The shape knowledge is inferred via the building primitives and used as constraints to improve the building models, in which all roof parameters are simultaneously adjusted. Experiments show the flexibility of building primitives in both lidar point cloud and stereo point cloud.
Advanced quadratures and periodic boundary conditions in parallel 3D S{sub n} transport
Manalo, K.; Yi, C.; Huang, M.; Sjoden, G.
2013-07-01
Significant updates in numerical quadratures have warranted investigation with 3D Sn discrete ordinates transport. We show new applications of quadrature departing from level symmetric (S{sub 2}o). investigating 3 recently developed quadratures: Even-Odd (EO), Linear-Discontinuous Finite Element - Surface Area (LDFE-SA), and the non-symmetric Icosahedral Quadrature (IC). We discuss implementation changes to 3D Sn codes (applied to Hybrid MOC-Sn TITAN and 3D parallel PENTRAN) that can be performed to accommodate Icosahedral Quadrature, as this quadrature is not 90-degree rotation invariant. In particular, as demonstrated using PENTRAN, the properties of Icosahedral Quadrature are suitable for trivial application using periodic BCs versus that of reflective BCs. In addition to implementing periodic BCs for 3D Sn PENTRAN, we implemented a technique termed 'angular re-sweep' which properly conditions periodic BCs for outer eigenvalue iterative loop convergence. As demonstrated by two simple transport problems (3-group fixed source and 3-group reflected/periodic eigenvalue pin cell), we remark that all of the quadratures we investigated are generally superior to level symmetric quadrature, with Icosahedral Quadrature performing the most efficiently for problems tested. (authors)
3-D simulation of gases transport under condition of inert gas injection into goaf
NASA Astrophysics Data System (ADS)
Liu, Mao-Xi; Shi, Guo-Qing; Guo, Zhixiong; Wang, Yan-Ming; Ma, Li-Yang
2016-02-01
To prevent coal spontaneous combustion in mines, it is paramount to understand O2 gas distribution under condition of inert gas injection into goaf. In this study, the goaf was modeled as a 3-D porous medium based on stress distribution. The variation of O2 distribution influenced by CO2 or N2 injection was simulated based on the multi-component gases transport and the Navier-Stokes equations using Fluent. The numerical results without inert gas injection were compared with field measurements to validate the simulation model. Simulations with inert gas injection show that CO2 gas mainly accumulates at the goaf floor level; however, a notable portion of N2 gas moves upward. The evolution of the spontaneous combustion risky zone with continuous inert gas injection can be classified into three phases: slow inerting phase, rapid accelerating inerting phase, and stable inerting phase. The asphyxia zone with CO2 injection is about 1.25-2.4 times larger than that with N2 injection. The efficacy of preventing and putting out mine fires is strongly related with the inert gas injecting position. Ideal injections are located in the oxidation zone or the transitional zone between oxidation zone and heat dissipation zone.
Numerical model of sonic boom in 3D kinematic turbulence
NASA Astrophysics Data System (ADS)
Coulouvrat, François; Luquet, David; Marchiano, Régis
2015-10-01
stratified wind superimposed to a 3D random turbulent realization. Propagation is performed either in the case of a shadow zone or of an atmospheric waveguide. To model the turbulent ABL, the mean flow and the fluctuations are handled separately. The wind fluctuations are generated using the Random Fluctuations Generation method assuming a von Kármán spectrum and a homogeneous and isotropic turbulence. The mean stratified wind is modeled based on the Monin-Obhukov Similarity Theory (MOST). To illustrate the method, the typical case of a sunny day with a strong wind has been chosen. Statistics are obtained on several parameters. It shows the importance of turbulence, which leads to an increase of the mean maximum peak pressure in the shadow zone and to its decrease in the waveguide. Moreover, the formation of random caustics that can lead to an increase of the noise perceived locally is outlined.
Methods for Geometric Data Validation of 3d City Models
NASA Astrophysics Data System (ADS)
Wagner, D.; Alam, N.; Wewetzer, M.; Pries, M.; Coors, V.
2015-12-01
Geometric quality of 3D city models is crucial for data analysis and simulation tasks, which are part of modern applications of the data (e.g. potential heating energy consumption of city quarters, solar potential, etc.). Geometric quality in these contexts is however a different concept as it is for 2D maps. In the latter case, aspects such as positional or temporal accuracy and correctness represent typical quality metrics of the data. They are defined in ISO 19157 and should be mentioned as part of the metadata. 3D data has a far wider range of aspects which influence their quality, plus the idea of quality itself is application dependent. Thus, concepts for definition of quality are needed, including methods to validate these definitions. Quality on this sense means internal validation and detection of inconsistent or wrong geometry according to a predefined set of rules. A useful starting point would be to have correct geometry in accordance with ISO 19107. A valid solid should consist of planar faces which touch their neighbours exclusively in defined corner points and edges. No gaps between them are allowed, and the whole feature must be 2-manifold. In this paper, we present methods to validate common geometric requirements for building geometry. Different checks based on several algorithms have been implemented to validate a set of rules derived from the solid definition mentioned above (e.g. water tightness of the solid or planarity of its polygons), as they were developed for the software tool CityDoctor. The method of each check is specified, with a special focus on the discussion of tolerance values where they are necessary. The checks include polygon level checks to validate the correctness of each polygon, i.e. closeness of the bounding linear ring and planarity. On the solid level, which is only validated if the polygons have passed validation, correct polygon orientation is checked, after self-intersections outside of defined corner points and edges
Construction of an extended library of adult male 3D models: rationale and results
NASA Astrophysics Data System (ADS)
Broggio, D.; Beurrier, J.; Bremaud, M.; Desbrée, A.; Farah, J.; Huet, C.; Franck, D.
2011-12-01
In order to best cover the possible extent of heights and weights of male adults the construction of 25 whole body 3D models has been undertaken. Such a library is thought to be useful to specify the uncertainties and relevance of dosimetry calculations carried out with models representing individuals of average body heights and weights. Representative 3D models of Caucasian body types are selected in a commercial database according to their height and weight, and 3D models of the skeleton and internal organs are designed using another commercial dataset. A review of the literature enabled one to fix volume or mass target values for the skeleton, soft organs, skin and fat content of the selected individuals. The composition of the remainder tissue is fixed so that the weight of the voxel models equals the weight of the selected individuals. After mesh and NURBS modelling, volume adjustment of the selected body shapes and additional voxel-based work, 25 voxel models with 109 identified organs or tissue are obtained. Radiation transport calculations are carried out with some of the developed models to illustrate potential uses. The following points are discussed throughout this paper: justification of the fixed or obtained models' features regarding available and relevant literature data; workflow and strategy for major modelling steps; advantages and drawbacks of the obtained library as compared with other works. The construction hypotheses are explained and justified in detail since future calculation results obtained with this library will depend on them.
Development of topography in 3-D continental-collision models
NASA Astrophysics Data System (ADS)
Pusok, A. E.; Kaus, Boris J. P.
2015-05-01
Understanding the formation and evolution of high mountain belts, such as the Himalayas and the adjacent Tibetan Plateau, has been the focus of many tectonic and numerical models. Here we employ 3-D numerical simulations to investigate the role that subduction, collision, and indentation play on lithosphere dynamics at convergent margins, and to analyze the conditions under which large topographic plateaus can form in an integrated lithospheric and upper mantle-scale model. Distinct dynamics are obtained for the oceanic subduction side (trench retreat, slab rollback) and the continental-collision side (trench advance, slab detachment, topographic uplift, lateral extrusion). We show that slab pull alone is insufficient to generate high topography in the upper plate, and that external forcing and the presence of strong blocks such as the Tarim Basin are necessary to create and shape anomalously high topographic fronts and plateaus. Moreover, scaling is used to predict four different modes of surface expression in continental-collision models: (I) low-amplitude homogeneous shortening, (II) high-amplitude homogeneous shortening, (III) Alpine-type topography with topographic front and low plateau, and (IV) Tibet-Himalaya-type topography with topographic front and high plateau. Results of semianalytical models suggest that the Argand number governs the formation of high topographic fronts, while the amplitude of plateaus is controlled by the initial buoyancy ratio of the upper plate. Applying these results to natural examples, we show that the Alps belong to regime (III), the Himalaya-Tibet to regime (IV), whereas the Andes-Altiplano fall at the boundary between regimes (III) and (IV).
EM modeling for GPIR using 3D FDTD modeling codes
Nelson, S.D.
1994-10-01
An analysis of the one-, two-, and three-dimensional electrical characteristics of structural cement and concrete is presented. This work connects experimental efforts in characterizing cement and concrete in the frequency and time domains with the Finite Difference Time Domain (FDTD) modeling efforts of these substances. These efforts include Electromagnetic (EM) modeling of simple lossless homogeneous materials with aggregate and targets and the modeling dispersive and lossy materials with aggregate and complex target geometries for Ground Penetrating Imaging Radar (GPIR). Two- and three-dimensional FDTD codes (developed at LLNL) where used for the modeling efforts. Purpose of the experimental and modeling efforts is to gain knowledge about the electrical properties of concrete typically used in the construction industry for bridges and other load bearing structures. The goal is to optimize the performance of a high-sample-rate impulse radar and data acquisition system and to design an antenna system to match the characteristics of this material. Results show agreement to within 2 dB of the amplitudes of the experimental and modeled data while the frequency peaks correlate to within 10% the differences being due to the unknown exact nature of the aggregate placement.
West Flank Coso, CA FORGE 3D temperature model
Doug Blankenship
2016-03-01
x,y,z data of the 3D temperature model for the West Flank Coso FORGE site. Model grid spacing is 250m. The temperature model for the Coso geothermal field used over 100 geothermal production sized wells and intermediate-depth temperature holes. At the near surface of this model, two boundary temperatures were assumed: (1) areas with surface manifestations, including fumaroles along the northeast striking normal faults and northwest striking dextral faults with the hydrothermal field, a temperature of ~104ËšC was applied to datum at +1066 meters above sea level elevation, and (2) a near-surface temperature at about 10 meters depth, of 20ËšC was applied below the diurnal and annual conductive temperature perturbations. These assumptions were based on heat flow studies conducted at the CVF and for the Mojave Desert. On the edges of the hydrothermal system, a 73ËšC/km (4ËšF/100â€™) temperature gradient contour was established using conductive gradient data from shallow and intermediate-depth temperature holes. This contour was continued to all elevation datums between the 20ËšC surface and -1520 meters below mean sea level. Because the West Flank is outside of the geothermal field footprint, during Phase 1, the three wells inside the FORGE site were incorporated into the preexisting temperature model. To ensure a complete model was built based on all the available data sets, measured bottom-hole temperature gradients in certain wells were downward extrapolated to the next deepest elevation datum (or a maximum of about 25% of the well depth where conductive gradients are evident in the lower portions of the wells). After assuring that the margins of the geothermal field were going to be adequately modelled, the data was contoured using the Kriging method algorithm. Although the extrapolated temperatures and boundary conditions are not rigorous, the calculated temperatures are anticipated to be within ~6ËšC (20ËšF), or one contour interval, of the
3D Smoothed Particle Hydrodynamics Models of Betelgeuse's Bow Shock
NASA Astrophysics Data System (ADS)
Mohamed, S.; Mackey, J.; Langer, N.
2013-05-01
Betelgeuse, the bright red supergiant (RSG) in Orion, is a runaway star. Its supersonic motion through the interstellar medium has resulted in the formation of a bow shock, a cometary structure pointing in the direction of motion. We present the first 3D hydrodynamic simulations of the formation and evolution of Betelgeuse's bow shock. We show that the bow shock morphology depends substantially on the growth timescale for Rayleigh-Taylor versus Kelvin-Helmholtz instabilities. We discuss our models in light of the recent Herschel, GALEX and VLA observations. If the mass in the bow shock shell is low (~few × 10-3 M⊙), as seems to be implied by the AKARI and Herschel observations, then Betelgeuse's bow shock is very young and is unlikely to have reached a steady state. The circular, smooth bow shock shell is consistent with this conclusion. We further discuss the implications of our results, in particular, the possibility that Betelgeuse may have only recently entered the RSG phase.
3D Simulation Modeling of the Tooth Wear Process
Dai, Ning; Hu, Jian; Liu, Hao
2015-01-01
Severe tooth wear is the most common non-caries dental disease, and it can seriously affect oral health. Studying the tooth wear process is time-consuming and difficult, and technological tools are frequently lacking. This paper presents a novel method of digital simulation modeling that represents a new way to study tooth wear. First, a feature extraction algorithm is used to obtain anatomical feature points of the tooth without attrition. Second, after the alignment of non-attrition areas, the initial homogeneous surface is generated by means of the RBF (Radial Basic Function) implicit surface and then deformed to the final homogeneous by the contraction and bounding algorithm. Finally, the method of bilinear interpolation based on Laplacian coordinates between tooth with attrition and without attrition is used to inversely reconstruct the sequence of changes of the 3D tooth morphology during gradual tooth wear process. This method can also be used to generate a process simulation of nonlinear tooth wear by means of fitting an attrition curve to the statistical data of attrition index in a certain region. The effectiveness and efficiency of the attrition simulation algorithm are verified through experimental simulation. PMID:26241942
Construction of an extended library of adult male 3D models: rationale and results.
Broggio, D; Beurrier, J; Bremaud, M; Desbrée, A; Farah, J; Huet, C; Franck, D
2011-12-01
In order to best cover the possible extent of heights and weights of male adults the construction of 25 whole body 3D models has been undertaken. Such a library is thought to be useful to specify the uncertainties and relevance of dosimetry calculations carried out with models representing individuals of average body heights and weights. Representative 3D models of Caucasian body types are selected in a commercial database according to their height and weight, and 3D models of the skeleton and internal organs are designed using another commercial dataset. A review of the literature enabled one to fix volume or mass target values for the skeleton, soft organs, skin and fat content of the selected individuals. The composition of the remainder tissue is fixed so that the weight of the voxel models equals the weight of the selected individuals. After mesh and NURBS modelling, volume adjustment of the selected body shapes and additional voxel-based work, 25 voxel models with 109 identified organs or tissue are obtained. Radiation transport calculations are carried out with some of the developed models to illustrate potential uses. The following points are discussed throughout this paper: justification of the fixed or obtained models’ features regarding available and relevant literature data; workflow and strategy for major modelling steps; advantages and drawbacks of the obtained library as compared with other works. The construction hypotheses are explained and justified in detail since future calculation results obtained with this library will depend on them. PMID:22086354
NASA Astrophysics Data System (ADS)
Sippel, Judith; Fuchs, Sven; Cacace, Mauro; Kastner, Oliver; Huenges, Ernst; Scheck-Wenderoth, Magdalena
2013-04-01
In the light of an aspired reduction of CO2 emissions for Germany's capital Berlin, one possible alternative for meeting the city's growing energy demands lies in deep geothermal energy. To minimise exploration risks, a profound knowledge about the subsurface temperature distribution is indispensable. We present a 3D structural model that is used for thermal modelling and thus correlates calculated subsurface temperatures with geothermally relevant structures in the deep subsurface of Berlin - an ideal base for improving the probability of finding adequate geothermal reservoirs. Berlin is located in the eastern part of the North German Basin which is filled with several thousand metres of Permian to Cenozoic sediments containing hot and water bearing aquifers to potentially be used as hydrothermal reservoirs. To characterise the geological underground, the 3D structural model integrates stratigraphical, petrophysical and well-log based information from local boreholes as well as stratigraphic trends from (seismic data based) regional 3D models. The model differentiates 21 geological units: 17 Permian-Cenozoic sedimentary layers, pre-Permian sediments, upper crust, lower crust and the lithospheric mantle. Based on this 3D geological model complemented by databased lithology-dependent thermal properties, two groups of numerical thermal simulations have been carried out: calculations of the steady-state conductive thermal field and simulations of coupled fluid and heat transport. The 3D thermal models predict large lateral variations in temperatures that are validated by high-precession temperature logs. These variations are mostly caused by three specific geological layers and their physical properties: the Permian Zechstein salt with its markedly high thermal conductivity and strong thickness variation (171-3442 m); the crystalline upper crustal layer with its high radiogenic heat production and decreasing thickness from east to west; and the Tertiary Rupelian
Optically directed molecular transport and 3D isoelectric positioning of amphoteric biomolecules
Hafeman, Dean G.; Harkins, James B.; WitkowskiII, Charles E.; Lewis, Nathan S.; Brown, Gilbert M; Warmack, Robert J Bruce; Thundat, Thomas George
2006-01-01
We demonstrate the formation of charged molecular packets and their transport within optically created electrical force-field traps in a pH-buffered electrolyte. We call this process photoelectrophoretic localization and transport (PELT). The electrolyte is in contact with a photoconductive semiconductor electrode and a counterelectrode that are connected through an external circuit. A light beam directed to coordinates on the photoconductive electrode surface produces a photocurrent within the circuit and electrolyte. Within the electrolyte, the photocurrent creates localized force-field traps centered at the illuminated coordinates. Charged molecules, including polypeptides and proteins, electrophoretically accumulate into the traps and subsequently can be transported in the electrolyte by moving the traps over the photoconductive electrode in response to movement of the light beam. The molecules in a single trap can be divided into aliquots, and the aliquots can be directed along multiple routes simultaneously by using multiple light beams. This photoelectrophoretic transport of charged molecules by PELT resembles the electrostatic transport of electrons within force-field wells of solid-state charge-coupled devices. The molecules, however, travel in a liquid electrolyte rather than a solid. Furthermore, we have used PELT to position amphoteric biomolecules in three dimensions. A 3D pH gradient was created in an electrolyte medium by controlling the illumination position on a photoconductive anode where protons were generated electrolytically. Photoelectrophoretic transport of amphoteric molecules through the pH gradient resulted in accumulation of the molecules at their apparent 3D isoelectric coordinates in the medium.
A 3D numerical model for Kepler's supernova remnant
NASA Astrophysics Data System (ADS)
Toledo-Roy, J. C.; Esquivel, A.; Velázquez, P. F.; Reynoso, E. M.
2014-07-01
We present new 3D numerical simulations for Kepler's supernova remnant. In this work we revisit the possibility that the asymmetric shape of the remnant in X-rays is the product of a Type Ia supernova explosion which occurs inside the wind bubble previously created by an AGB companion star. Due to the large peculiar velocity of the system, the interaction of the strong AGB wind with the interstellar medium results in a bow shock structure. In this new model we propose that the AGB wind is anisotropic, with properties such as mass-loss rate and density having a latitude dependence, and that the orientation of the polar axis of the AGB star is not aligned with the direction of motion. The ejecta from the Type Ia supernova explosion is modelled using a power-law density profile, and we let the remnant evolve for 400 yr. We computed synthetic X-ray maps from the numerical results. We find that the estimated size and peculiar X-ray morphology of Kepler's supernova remnant are well reproduced by considering an AGB mass-loss rate of 10-5 M⊙ yr-1, a wind terminal velocity of 10 km s-1, an ambient medium density of 10-3 cm-3 and an explosion energy of 7 × 1050 erg. The obtained total X-ray luminosity of the remnant in this model reaches 6 × 1050 erg, which is within a factor of 2 of the observed value, and the time evolution of the luminosity shows a rate of decrease in recent decades of ˜2.4 per cent yr-1 that is consistent with the observations.
3D modeling of carbonates petro-acoustic heterogeneities
NASA Astrophysics Data System (ADS)
Baden, Dawin; Guglielmi, Yves; Saracco, Ginette; Marié, Lionel; Viseur, Sophie
2015-04-01
Characterizing carbonate reservoirs heterogeneity is a challenging issue for Oil & Gas Industry, CO2 sequestration and all kinds of fluid manipulations in natural reservoirs, due to the significant impact of heterogeneities on fluid flow and storage within the reservoir. Although large scale (> meter) heterogeneities such as layers petrophysical contrasts are well addressed by computing facies-based models, low scale (< meter) heterogeneities are often poorly constrained because of the complexity in predicting their spatial arrangement. In this study, we conducted petro-acoustic measurements on cores of different size and diameter (Ø = 1", 1.5" and 5") in order to evaluate anisotropy or heterogeneity in carbonates at different laboratory scales. Different types of heterogeneities which generally occur in carbonate reservoir units (e.g. petrographic, diagenetic, and tectonic related) were sampled. Dry / wet samples were investigated with different ultrasonic apparatus and using different sensors allowing acoustic characterization through a bandwidth varying from 50 to 500 kHz. Comprehensive measurements realized on each samples allowed statistical analyses of petro-acoustic properties such as attenuation, shear and longitudinal wave velocity. The cores properties (geological and acoustic facies) were modeled in 3D using photogrammetry and GOCAD geo-modeler. This method successfully allowed detecting and imaging in three dimensions differential diagenesis effects characterized by the occurrence of decimeter-scale diagenetic horizons in samples assumed to be homogeneous and/or different diagenetic sequences between shells filling and the packing matrix. We then discuss how small interfaces such as cracks, stylolithes and laminations which are also imaged may have guided these differential effects, considering that understanding the processes may be taken as an analogue to actual fluid drainage complexity in deep carbonate reservoir.
2D/1D approximations to the 3D neutron transport equation. II: Numerical comparisons
Kelley, B. W.; Collins, B.; Larsen, E. W.
2013-07-01
In a companion paper [1], (i) several new '2D/1D equations' are introduced as accurate approximations to the 3D Boltzmann transport equation, (ii) the simplest of these approximate equations is systematically discretized, and (iii) a theoretically stable iteration scheme is developed to solve the discrete equations. In this paper, numerical results are presented that confirm the theoretical predictions made in [1]. (authors)
3-D Particl-in-Cell Simulations of Transport Driven Currents
NASA Astrophysics Data System (ADS)
Tsung, F. S.; Dawson, J. M.
1997-11-01
In the advanced tokamak regime, transport phenomena can account for a signficant fraction of the toroidal current, possibly over that driven directly by the ohmic heating electric fields. Although bootstrap theory accounts for contributions of the collisional modification of banana orbits on the toroidal currents, the corresponding transport theory does not accurately predict the transport of particles and heat in present-day tokamak experiments. Furthermore, in our previous simulations in 21/2-D, currents were spontaneously generated in both the cylindrical and the toroidal geometries, contrary to neoclassical predictions. In these calculations, it was believed that the driving mechanism is the preferential loss of particles whose initial velocity is opposite to that of the plasma current. Because the preferential loss mechanism assumes the conservation of toroidal angular momentum, we have extended these simulations to three dimensions to study the effects of toroidal assymetries. A parallel, 3-D electromagnetic PIC code running on the IBM SP, with a localized field-solver has been developed to investigate the effects of perturbations parallel to the field lines, and direct comparisons has been made between the 21/2-D and 3-D simulations, and we have found good agreements between the 2 1/2-D calculations and the 3-D results. We will present these results at the meeting.
GPU accelerated simulations of 3D deterministic particle transport using discrete ordinates method
NASA Astrophysics Data System (ADS)
Gong, Chunye; Liu, Jie; Chi, Lihua; Huang, Haowei; Fang, Jingyue; Gong, Zhenghu
2011-07-01
Graphics Processing Unit (GPU), originally developed for real-time, high-definition 3D graphics in computer games, now provides great faculty in solving scientific applications. The basis of particle transport simulation is the time-dependent, multi-group, inhomogeneous Boltzmann transport equation. The numerical solution to the Boltzmann equation involves the discrete ordinates ( Sn) method and the procedure of source iteration. In this paper, we present a GPU accelerated simulation of one energy group time-independent deterministic discrete ordinates particle transport in 3D Cartesian geometry (Sweep3D). The performance of the GPU simulations are reported with the simulations of vacuum boundary condition. The discussion of the relative advantages and disadvantages of the GPU implementation, the simulation on multi GPUs, the programming effort and code portability are also reported. The results show that the overall performance speedup of one NVIDIA Tesla M2050 GPU ranges from 2.56 compared with one Intel Xeon X5670 chip to 8.14 compared with one Intel Core Q6600 chip for no flux fixup. The simulation with flux fixup on one M2050 is 1.23 times faster than on one X5670.
GPU accelerated simulations of 3D deterministic particle transport using discrete ordinates method
Gong Chunye; Liu Jie; Chi Lihua; Huang Haowei; Fang Jingyue; Gong Zhenghu
2011-07-01
Graphics Processing Unit (GPU), originally developed for real-time, high-definition 3D graphics in computer games, now provides great faculty in solving scientific applications. The basis of particle transport simulation is the time-dependent, multi-group, inhomogeneous Boltzmann transport equation. The numerical solution to the Boltzmann equation involves the discrete ordinates (S{sub n}) method and the procedure of source iteration. In this paper, we present a GPU accelerated simulation of one energy group time-independent deterministic discrete ordinates particle transport in 3D Cartesian geometry (Sweep3D). The performance of the GPU simulations are reported with the simulations of vacuum boundary condition. The discussion of the relative advantages and disadvantages of the GPU implementation, the simulation on multi GPUs, the programming effort and code portability are also reported. The results show that the overall performance speedup of one NVIDIA Tesla M2050 GPU ranges from 2.56 compared with one Intel Xeon X5670 chip to 8.14 compared with one Intel Core Q6600 chip for no flux fixup. The simulation with flux fixup on one M2050 is 1.23 times faster than on one X5670.
Brien, Dianne L.; Reid, Mark E.
2007-01-01
Landslides are a common problem on coastal bluffs throughout the world. Along the coastal bluffs of the Puget Sound in Seattle, Washington, landslides range from small, shallow failures to large, deep-seated landslides. Landslides of all types can pose hazards to human lives and property, but deep-seated landslides are of significant concern because their large areal extent can cause extensive property damage. Although many geomorphic processes shape the coastal bluffs of Seattle, we focus on large (greater than 3,000 m3), deepseated, rotational landslides that occur on the steep bluffs along Puget Sound. Many of these larger failures occur in advance outwash deposits of the Vashon Drift (Qva); some failures extend into the underlying Lawton Clay Member of the Vashon Drift (Qvlc). The slope stability of coastal bluffs is controlled by the interplay of three-dimensional (3-D) variations in gravitational stress, strength, and pore-water pressure. We assess 3-D slope-stability using SCOOPS (Reid and others, 2000), a computer program that allows us to search a high-resolution digital-elevation model (DEM) to quantify the relative stability of all parts of the landscape by computing the stability and volume of thousands of potential spherical failures. SCOOPS incorporates topography, 3-D strength variations, and 3-D pore pressures. Initially, we use our 3-D analysis methods to examine the effects of topography and geology by using heterogeneous material properties, as defined by stratigraphy, without pore pressures. In this scenario, the least-stable areas are located on the steepest slopes, commonly in Qva or Qvlc. However, these locations do not agree well with observations of deep-seated landslides. Historically, both shallow colluvial landslides and deep-seated landslides have been observed near the contact between Qva and Qvlc, and commonly occur in Qva. The low hydraulic conductivity of Qvlc impedes ground-water flow, resulting in elevated pore pressures at the
3D Geologic Model of the Southern Great Basin
NASA Astrophysics Data System (ADS)
Wagoner, J. L.; Myers, S. C.
2006-12-01
We have constructed a regional 3D geologic model of the southern Great Basin, in support of a seismic wave propagation investigation of the 1993 Nonproliferation Experiment (NPE) at the Nevada Test Site (NTS). The model is centered on the NPE and spans longitude -119.5° to -112.6°, latitude 34.5° to 39.8°, and a depth from the surface to 150 km below sea level. Hence, the model includes the southern half of Nevada, as well as parts of eastern California, western Utah, and a portion of northwestern Arizona. The upper crust is constrained by geologic and geophysical studies, and the lower crust and upper mantle are constrained by geophysical studies. The upper crustal geologic units are Quaternary basin fill, Tertiary deposits, pre-Tertiary deposits, intrusive rocks, and calderas. The lower crust and upper mantle are parameterized with 8 layers, including the Moho. Detailed geologic data, including surface maps, borehole data, and geophysical surveys, were used to define the geology at the NTS. Digital geologic outcrop data were available for both Nevada and Arizona, whereas we scanned and hand digitized geologic maps for California and Utah. Published gravity data (2km spacing) were used to determine the thickness of the Cenozoic deposits and constrain the depth of the basins. The free surface is based on a 10m lateral resolution DEM at the NTS and a 90m resolution DEM elsewhere. The gross geophysical structure of the crust and upper mantle is taken from regional surface-wave studies. Variations in crustal thickness are based on receiver function analysis and a compilation of reflection/refraction studies. We used the Earthvision (Dynamic Graphics, Inc.) software to integrate the geologic and geophysical information into a model of x,y,z,p nodes, where p is an integer index representing the geologic unit. For regional seismic simulations we convert this realistic geologic model into elastic parameters. Upper crustal units are treated as seismically homogeneous
NASA Astrophysics Data System (ADS)
Giri, Abhra; Tarafdar, Sujata; Gouze, Philippe; Dutta, Tapati
2013-03-01
Several studies, both theoretical and experimental, show that sedimentary rocks have a fractal pore-grain interface. In this paper a computer simulated 3-D sedimentary rock structure generated by the Relaxed Ballistic Bidisperse Deposition Model (RBBDM), is investigated to characterize the micro structure of its pores. The pore volume and the rock-pore interface show the same fractal dimension indicating that the pore volume is a fractal. The two point density correlation is computed for the pore space and the results compare favourably with the range reported from experiments. An array of 2-D X-ray tomography micrograph sections of a real sedimentary rock, an oolitic limestone (pure calcite) from the Mondeville formation of Middle Jurassic age (Paris Basin, France), was used to generate a 3-D bitmap. The 3-D real rock sample generated in this manner, was analysed for similar studies as the simulated structure. The results were compared with those obtained from simulation. The simulation results agree qualitatively with the real rock sample. Diffusion through the connected pore space of the simulated structure was studied using a random walk algorithm and the results compared with the similar simulation study done on the 3-D oolitic limestone specimen. In both cases diffusion was found to be anomalous indicating that the sedimentary rock has a fractal geometry. The favourable comparability of results between the simulated and real rock supports the usefulness of the model of sedimentary rock generation which can be applicable to transport phenomena.
3D Geological Model of Nihe ore deposit Constrained by Gravity and Magnetic Modeling
NASA Astrophysics Data System (ADS)
Qi, Guang; Yan, Jiayong; Lv, Qingtan; Zhao, Jinhua
2016-04-01
We present a case study on using integrated geologic model in mineral exploration at depth. Nihe ore deposit in Anhui Province, is deep hidden ore deposit which was discovered in recent years, this finding is the major driving force of deep mineral exploration work in Luzong. Building 3D elaborate geological model has the important significance for prospecting to deep or surround in this area, and can help us better understand the metallogenic law and ore-controlling regularity. A 3D geological model, extending a depth from +200m to -1500m in Nihe ore deposit, has been compiled from surface geological map, cross-section, borehole logs and amounts of geological inference. And then the 3D geological models have been given physical property parameter for calculating the potential field. Modelling the potential response is proposed as means of evaluating the viability of the 3D geological models, and the evidence of making small changes to the uncertain parts of the original 3D geological models. It is expected that the final models not only reproduce supplied prior geological knowledge, but also explain the observed geophysical data. The workflow used to develop the 3D geologic model in this study includes the three major steps, as follows: (1) Determine the basic information of Model: Defining the 3D limits of the model area, the basic geological and structural unit, and the tectonic contact relations and the sedimentary sequences between these units. (2) 3D model construction: Firstly, a series of 2D geological cross sections over the model area are built by using all kinds of prior information, including surface geology, borehole data, seismic sections, and local geologists' knowledge and intuition. Lastly, we put these sections into a 3D environment according to their profile locations to build a 3D model by using geostatistics method. (3) 3D gravity and magnetic modeling: we calculate the potential field responses of the 3D model, and compare the predicted and
3d Modelling of Convective Flow In The Rhine Graben
NASA Astrophysics Data System (ADS)
Bächler, D.; Kohl, T.; Rybach, L.
Detailed investigations of the temperature distribution in the Rhine Graben indi- cate regular pattern of thermal anomalies following major north-south striking faults. These anomalies remain unexplained by conventional Rhine Graben studies based on 2D east-west striking sections. First analytical solutions for convective flow in vertical faults are applied for a clearly observable anomalous temperature pattern along ma- jor Rhine Graben faults. By these calculations the fault height, fault aperture, minimal fault permeability and time to convective onset is derived from the observed distances. Since analytical solutions are limited to simple model geometries further improvement was achieved by numerical model simulations, which allow to assume more com- plex initial and boundary conditions. Using the finite volume code TOUGH2 series of anomalies following the same fault were simulated by a 3D numerical model. Fo- cussing on the predominant north-south permeability structure the model consists of a vertical north-south striking fault and surrounding matrix. The fault geometries are based on the analytically predicted fault geometries (aperture=200m, height=3500m) and on the observed temperatures. Comparison of simulation results with observed temperatures shows that the fault is situated between 500 to 600m and 4200m. The fault permeability is taken as 5*10-13m2 and the fluid velocity in the fault is calcu- lated as 10-9 to 10-10 m/s. These results indicate the importance of our considerations since mass flux is much higher in the faults than across them. The minimal age of the anomaly is considered to be 77'000 years, since steady state is reached after this time span. The study proves that the observed temperature anomaly pattern along the gamma fault at Landau can be explained by north-south striking convection systems within fault zones. Similar situations have been found at Soultz. This may be a hint on a general feature of the major north-south striking
Numerical Results of 3-D Modeling of Moon Accumulation
NASA Astrophysics Data System (ADS)
Khachay, Yurie; Anfilogov, Vsevolod; Antipin, Alexandr
2014-05-01
For the last time for the model of the Moon usually had been used the model of mega impact in which the forming of the Earth and its sputnik had been the consequence of the Earth's collision with the body of Mercurial mass. But all dynamical models of the Earth's accumulation and the estimations after the Pb-Pb system, lead to the conclusion that the duration of the planet accumulation was about 1 milliard years. But isotopic results after the W-Hf system testify about a very early (5-10) million years, dividing of the geochemical reservoirs of the core and mantle. In [1,2] it is shown, that the account of energy dissipating by the decay of short living radioactive elements and first of all Al26,it is sufficient for heating even small bodies with dimensions about (50-100) km up to the iron melting temperature and can be realized a principal new differentiation mechanism. The inner parts of the melted preplanets can join and they are mainly of iron content, but the cold silicate fragments return to the supply zone and additionally change the content of Moon forming to silicates. Only after the increasing of the gravitational radius of the Earth, the growing area of the future Earth's core can save also the silicate envelope fragments [3]. For understanding the further system Earth-Moon evolution it is significant to trace the origin and evolution of heterogeneities, which occur on its accumulation stage.In that paper we are modeling the changing of temperature,pressure,velocity of matter flowing in a block of 3d spherical body with a growing radius. The boundary problem is solved by the finite-difference method for the system of equations, which include equations which describe the process of accumulation, the Safronov equation, the equation of impulse balance, equation Navier-Stocks, equation for above litho static pressure and heat conductivity in velocity-pressure variables using the Businesque approach.The numerical algorithm of the problem solution in velocity
Towards an Anisotropic Whole Mantle 3D Elastic Velocity Model
NASA Astrophysics Data System (ADS)
Panning, M. P.; Romanowicz, B.; Gung, Y.
2001-12-01
Many studies have documented the existence of anisotropy in the earth's upper mantle, concentrated in the top 200 km. This evidence comes from the study of surface waves as well as shear wave splitting. There is also evidence for shear wave splitting in D", at least in well sampled regions. There are some hints of anisotropy at the base of the transition zone. Tomographic models of the upper mantle have been developed with simplifying assumptions about the nature of the anisotropy, in order to minimize the number of free parameters in the inversions. Some assume transverse isotropy (e.g Ekström and Dziewonski, 1997), others include additional degrees of freedom with some realistic constraints on mineralogy (e.g. Montagner and Tanimoto, 1991). Our goal is to investigate anisotropy in the whole mantle, using the framework of waveform inversion, and the nonlinear asymptotic mode coupling theory (NACT), previously developed and applied to the construction of whole-mantle SH velocity models (Li and Romanowicz, 1996; Mégnin and Romanowicz, 2000). For this we require a 3 component dataset, and we have extended our automatic transverse (T) component wavepicking procedures to the vertical (Z) and longitudinal (L) component - a non-trivial task given the large number of phases present in the coupled P-SV system. A useful initial assumption, for which the theory has been readily adapted, is that of transverse isotropy. As a first step towards this, we have been investigating inversions using T component and Z,L component data separately. In particular, this allows us to explore the sampling that can be achieved with Z,L component data alone in the deepest part of the mantle. Indeed, D" is in general much better sampled in SH than in SV, owing to the availability of SHdiff at large distances, while SVdiff decays more rapidly due to mantle-core coupling. We present the results of our resolution experiments and discuss the differences between the 3D SV model obtained in well
Orbiter/External Tank Mate 3-D Solid Modeling
NASA Technical Reports Server (NTRS)
Godfrey, G. S.; Brandt, B.; Rorden, D.; Kapr, F.
2004-01-01
This research and development project presents an overview of the work completed while attending a summer 2004 American Society of Engineering Education/National Aeronautics and Space Administration (ASEE/NASA) Faculty Fellowship. This fellowship was completed at the Kennedy Space Center, Florida. The scope of the project was to complete parts, assemblies, and drawings that could be used by Ground Support Equipment (GSE) personnel to simulate situations and scenarios commonplace to the space shuttle Orbiter/External Tank (ET) Mate (50004). This mate takes place in the Vehicle Assembly Building (VAB). These simulations could then be used by NASA engineers as decision-making tools. During the summer of 2004, parts were created that defined the Orbiter/ET structural interfaces. Emphasis was placed upon assemblies that included the Orbiter/ET forward attachment (EO-1), aft left thrust strut (EO-2), aft right tripod support structure (EO-3), and crossbeam and aft feedline/umbilical supports. These assemblies are used to attach the Orbiter to the ET. The Orbiter/ET Mate assembly was then used to compare and analyze clearance distances using different Orbiter hang angles. It was found that a 30-minute arc angle change in Orbiter hang angle affected distance at the bipod strut to Orbiter yoke fitting 8.11 inches. A 3-D solid model library was established as a result of this project. This library contains parts, assemblies, and drawings translated into several formats. This library contains a collection of the following files: sti for sterolithography, stp for neutral file work, shrinkwrap for compression. tiff for photoshop work, jpeg for Internet use, and prt and asm for Pro/Engineer use. This library was made available to NASA engineers so that they could access its contents to make angle, load, and clearance analysis studies. These decision-making tools may be used by Pro/Engineer users and non-users.
Automated robust generation of compact 3D statistical shape models
NASA Astrophysics Data System (ADS)
Vrtovec, Tomaz; Likar, Bostjan; Tomazevic, Dejan; Pernus, Franjo
2004-05-01
Ascertaining the detailed shape and spatial arrangement of anatomical structures is important not only within diagnostic settings but also in the areas of planning, simulation, intraoperative navigation, and tracking of pathology. Robust, accurate and efficient automated segmentation of anatomical structures is difficult because of their complexity and inter-patient variability. Furthermore, the position of the patient during image acquisition, the imaging device and protocol, image resolution, and other factors induce additional variations in shape and appearance. Statistical shape models (SSMs) have proven quite successful in capturing structural variability. A possible approach to obtain a 3D SSM is to extract reference voxels by precisely segmenting the structure in one, reference image. The corresponding voxels in other images are determined by registering the reference image to each other image. The SSM obtained in this way describes statistically plausible shape variations over the given population as well as variations due to imperfect registration. In this paper, we present a completely automated method that significantly reduces shape variations induced by imperfect registration, thus allowing a more accurate description of variations. At each iteration, the derived SSM is used for coarse registration, which is further improved by describing finer variations of the structure. The method was tested on 64 lumbar spinal column CT scans, from which 23, 38, 45, 46 and 42 volumes of interest containing vertebra L1, L2, L3, L4 and L5, respectively, were extracted. Separate SSMs were generated for each vertebra. The results show that the method is capable of reducing the variations induced by registration errors.
LATIS3D: The Goal Standard for Laser-Tissue-Interaction Modeling
NASA Astrophysics Data System (ADS)
London, R. A.; Makarewicz, A. M.; Kim, B. M.; Gentile, N. A.; Yang, T. Y. B.
2000-03-01
The goal of this LDRD project has been to create LATIS3D-the world's premier computer program for laser-tissue interaction modeling. The development was based on recent experience with the 2D LATIS code and the ASCI code, KULL. With LATIS3D, important applications in laser medical therapy were researched including dynamical calculations of tissue emulsification and ablation, photothermal therapy, and photon transport for photodynamic therapy. This project also enhanced LLNL's core competency in laser-matter interactions and high-energy-density physics by pushing simulation codes into new parameter regimes and by attracting external expertise. This will benefit both existing LLNL programs such as ICF and SBSS and emerging programs in medical technology and other laser applications. The purpose of this project was to develop and apply a computer program for laser-tissue interaction modeling to aid in the development of new instruments and procedures in laser medicine.
Research on urban rapid 3D modeling and application based on CGA rule
NASA Astrophysics Data System (ADS)
Li, Jing-wen; Jiang, Jian-wu; Zhou, Song; Yin, Shou-qiang
2015-12-01
Use CityEngine as the 3D modeling platform, research on urban rapid 3D modeling technology based on the CGA(Computer Generated Architectur) rule , solved the problem of the rapid creation of urban 3D model in large scenes , and research on building texture processing and 3D model optimization techniques based on CGA rule , using component modeling method , solved the problem of texture distortion and model redundancy in the traditional fast modeling 3D model , and development of a three-dimensional view and analysis system based on ArcGIS Engine , realization of 3D model query , distance measurement , specific path flight , 3D marking , Scene export,etc.
Examination of 1D Solar Cell Model Limitations Using 3D SPICE Modeling: Preprint
McMahon, W. E.; Olson, J. M.; Geisz, J. F.; Friedman, D. J.
2012-06-01
To examine the limitations of one-dimensional (1D) solar cell modeling, 3D SPICE-based modeling is used to examine in detail the validity of the 1D assumptions as a function of sheet resistance for a model cell. The internal voltages and current densities produced by this modeling give additional insight into the differences between the 1D and 3D models.
3D nonrigid registration via optimal mass transport on the GPU.
Ur Rehman, Tauseef; Haber, Eldad; Pryor, Gallagher; Melonakos, John; Tannenbaum, Allen
2009-12-01
In this paper, we present a new computationally efficient numerical scheme for the minimizing flow approach for optimal mass transport (OMT) with applications to non-rigid 3D image registration. The approach utilizes all of the gray-scale data in both images, and the optimal mapping from image A to image B is the inverse of the optimal mapping from B to A. Further, no landmarks need to be specified, and the minimizer of the distance functional involved is unique. Our implementation also employs multigrid, and parallel methodologies on a consumer graphics processing unit (GPU) for fast computation. Although computing the optimal map has been shown to be computationally expensive in the past, we show that our approach is orders of magnitude faster then previous work and is capable of finding transport maps with optimality measures (mean curl) previously unattainable by other works (which directly influences the accuracy of registration). We give results where the algorithm was used to compute non-rigid registrations of 3D synthetic data as well as intra-patient pre-operative and post-operative 3D brain MRI datasets. PMID:19135403
3D nonrigid registration via optimal mass transport on the GPU
Rehman, Tauseef ur; Haber, Eldad; Pryor, Gallagher; Melonakos, John; Tannenbaum, Allen
2009-01-01
In this paper, we present a new computationally efficient numerical scheme for the minimizing flow approach for optimal mass transport (OMT) with applications to non-rigid 3D image registration. The approach utilizes all of the gray-scale data in both images, and the optimal mapping from image A to image B is the inverse of the optimal mapping from B to A. Further, no landmarks need to be specified, and the minimizer of the distance functional involved is unique. Our implementation also employs multigrid, and parallel methodologies on a consumer graphics processing unit (GPU) for fast computation. Although computing the optimal map has been shown to be computationally expensive in the past, we show that our approach is orders of magnitude faster then previous work and is capable of finding transport maps with optimality measures (mean curl) previously unattainable by other works (which directly influences the accuracy of registration). We give results where the algorithm was used to compute non-rigid registrations of 3D synthetic data as well as intra-patient pre-operative and post-operative 3D brain MRI datasets. PMID:19135403
Using 3D Geometric Models to Teach Spatial Geometry Concepts.
ERIC Educational Resources Information Center
Bertoline, Gary R.
1991-01-01
An explanation of 3-D Computer Aided Design (CAD) usage to teach spatial geometry concepts using nontraditional techniques is presented. The software packages CADKEY and AutoCAD are described as well as their usefulness in solving space geometry problems. (KR)
NASA Astrophysics Data System (ADS)
Fadel, I.; van der Meijde, M.; Kerle, N.; Lauritsen, N.
2015-03-01
Non-uniqueness of satellite gravity interpretation has traditionally been reduced by using a priori information from seismic tomography models. This reduction in the non-uniqueness has been based on velocity-density conversion formulas or user interpretation of the 3D subsurface structures (objects) based on the seismic tomography models and then forward modelling these objects. However, this form of object-based approach has been done without a standardized methodology on how to extract the subsurface structures from the 3D models. In this research, a 3D object-oriented image analysis (3D OOA) approach was implemented to extract the 3D subsurface structures from geophysical data. The approach was applied on a 3D shear wave seismic tomography model of the central part of the East African Rift System. Subsequently, the extracted 3D objects from the tomography model were reconstructed in the 3D interactive modelling environment IGMAS+, and their density contrast values were calculated using an object-based inversion technique to calculate the forward signal of the objects and compare it with the measured satellite gravity. Thus, a new object-based approach was implemented to interpret and extract the 3D subsurface objects from 3D geophysical data. We also introduce a new approach to constrain the interpretation of the satellite gravity measurements that can be applied using any 3D geophysical model.
Quasi-Facial Communication for Online Learning Using 3D Modeling Techniques
ERIC Educational Resources Information Center
Wang, Yushun; Zhuang, Yueting
2008-01-01
Online interaction with 3D facial animation is an alternative way of face-to-face communication for distance education. 3D facial modeling is essential for virtual educational environments establishment. This article presents a novel 3D facial modeling solution that facilitates quasi-facial communication for online learning. Our algorithm builds…
Howard Barker; Jason Cole
2012-05-17
Utilization of cloud-resolving models and multi-dimensional radiative transfer models to investigate the importance of 3D radiation effects on the numerical simulation of cloud fields and their properties.
Navier-Stokes Neutral and Plasma Fluid Modelling in 3D
Riemann, J; Borchardt, M; Schneider, R; Mutzke, A; Rognlien, T; Umansky, M
2004-05-17
The 3D finite volume transport code BoRiS is applied to a system of coupled plasma and neutral fluid equations in a slab. Demonstrating easy implementation of new equations, a new parallel BoRiS version is tested on three different models for the neutral fluid - diffusive, parallel Navier-Stokes and full Navier-Stokes - and the results are compared to each other. Typical effects like density enhancement by ionization of recycled neutrals in front of a target plate can be seen and differences are linked to the neutral models in use.
Transforming 2d Cadastral Data Into a Dynamic Smart 3d Model
NASA Astrophysics Data System (ADS)
Tsiliakou, E.; Labropoulos, T.; Dimopoulou, E.
2013-08-01
3D property registration has become an imperative need in order to optimally reflect all complex cases of the multilayer reality of property rights and restrictions, revealing their vertical component. This paper refers to the potentials and multiple applications of 3D cadastral systems and explores the current state-of-the art, especially the available software with which 3D visualization can be achieved. Within this context, the Hellenic Cadastre's current state is investigated, in particular its data modeling frame. Presenting the methodologies and specifications addressing the registration of 3D properties, the operating cadastral system's shortcomings and merits are pointed out. Nonetheless, current technological advances as well as the availability of sophisticated software packages (proprietary or open source) call for 3D modeling. In order to register and visualize the complex reality in 3D, Esri's CityEngine modeling software has been used, which is specialized in the generation of 3D urban environments, transforming 2D GIS Data into Smart 3D City Models. The application of the 3D model concerns the Campus of the National Technical University of Athens, in which a complex ownership status is established along with approved special zoning regulations. The 3D model was built using different parameters based on input data, derived from cadastral and urban planning datasets, as well as legal documents and architectural plans. The process resulted in a final 3D model, optimally describing the cadastral situation and built environment and proved to be a good practice example of 3D visualization.
Multi Sensor Data Integration for AN Accurate 3d Model Generation
NASA Astrophysics Data System (ADS)
Chhatkuli, S.; Satoh, T.; Tachibana, K.
2015-05-01
The aim of this paper is to introduce a novel technique of data integration between two different data sets, i.e. laser scanned RGB point cloud and oblique imageries derived 3D model, to create a 3D model with more details and better accuracy. In general, aerial imageries are used to create a 3D city model. Aerial imageries produce an overall decent 3D city models and generally suit to generate 3D model of building roof and some non-complex terrain. However, the automatically generated 3D model, from aerial imageries, generally suffers from the lack of accuracy in deriving the 3D model of road under the bridges, details under tree canopy, isolated trees, etc. Moreover, the automatically generated 3D model from aerial imageries also suffers from undulated road surfaces, non-conforming building shapes, loss of minute details like street furniture, etc. in many cases. On the other hand, laser scanned data and images taken from mobile vehicle platform can produce more detailed 3D road model, street furniture model, 3D model of details under bridge, etc. However, laser scanned data and images from mobile vehicle are not suitable to acquire detailed 3D model of tall buildings, roof tops, and so forth. Our proposed approach to integrate multi sensor data compensated each other's weakness and helped to create a very detailed 3D model with better accuracy. Moreover, the additional details like isolated trees, street furniture, etc. which were missing in the original 3D model derived from aerial imageries could also be integrated in the final model automatically. During the process, the noise in the laser scanned data for example people, vehicles etc. on the road were also automatically removed. Hence, even though the two dataset were acquired in different time period the integrated data set or the final 3D model was generally noise free and without unnecessary details.
Numerical Results of Earth's Core Accumulation 3-D Modelling
NASA Astrophysics Data System (ADS)
Khachay, Yurie; Anfilogov, Vsevolod
2013-04-01
For a long time as a most convenient had been the model of mega impact in which the early forming of the Earth's core and mantle had been the consequence of formed protoplanet collision with the body of Mercurial mass. But all dynamical models of the Earth's accumulation and the estimations after the Pb-Pb system, lead to the conclusion that the duration of the planet accumulation was about 1 milliard years. But isotopic results after the W-Hf system testify about a very early (5-10) million years, dividing of the geochemical reservoirs of the core and mantle. In [1,3] it is shown, that the account of energy dissipating by the decay of short living radioactive elements and first of all Al,it is sufficient for heating even small bodies with dimensions about (50-100) km up to the iron melting temperature and can be realized a principal new differentiation mechanism. The inner parts of the melted preplanets can join and they are mainly of iron content, but the cold silicate fragments return to the supply zone. Only after the increasing of the gravitational radius, the growing area of the future core can save also the silicate envelope fragments. All existing dynamical accumulation models are constructed by using a spherical-symmetrical model. Hence for understanding the further planet evolution it is significant to trace the origin and evolution of heterogeneities, which occur on the planet accumulation stage. In that paper we are modeling distributions of temperature, pressure, velocity of matter flowing in a block of 3D- spherical body with a growing radius. The boundary problem is solved by the finite-difference method for the system of equations, which include equations which describe the process of accumulation, the Safronov equation, the equation of impulse balance, equation Navier-Stocks, equation for above litho static pressure and heat conductivity in velocity-pressure variables using the Businesque approach. The numerical algorithm of the problem solution in
Teo, B G; Sarinder, K K S; Lim, L H S
2010-08-01
Three-dimensional (3D) models of the marginal hooks, dorsal and ventral anchors, bars and haptoral reservoirs of a parasite, Sundatrema langkawiense Lim & Gibson, 2009 (Monogenea) were developed using the polygonal modelling method in Autodesk 3ds Max (Version 9) based on two-dimensional (2D) illustrations. Maxscripts were written to rotate the modelled 3D structures. Appropriately orientated 3D haptoral hard-parts were then selected and positioned within the transparent 3D outline of the haptor and grouped together to form a complete 3D haptoral entity. This technique is an inexpensive tool for constructing 3D models from 2D illustrations for 3D visualisation of the spatial relationships between the different structural parts within organisms. PMID:20962723
NASA Astrophysics Data System (ADS)
Ghita, Gabriel; Sjoden, Glenn; Baciak, James; Huang, Nancy
2006-05-01
The Florida Institute for Nuclear Detection and Security (FINDS) is currently working on the design and evaluation of a prototype neutron detector array that may be used for parcel screening systems and homeland security applications. In order to maximize neutron detector response over a wide spectrum of energies, moderator materials of different compositions and amounts are required, and can be optimized through 3-D discrete ordinates and Monte Carlo model simulations verified through measurement. Pu-Be sources can be used as didactic source materials to augment the design, optimization, and construction of detector arrays with proper characterization via transport analysis. To perform the assessments of the Pu-Be Source Capsule, 3-D radiation transport computations are used, including Monte Carlo (MCNP5) and deterministic (PENTRAN) methodologies. In establishing source geometry, we based our model on available source schematic data. Because both the MCNP5 and PENTRAN codes begin with source neutrons, exothermic (α,n) reactions are modeled using the SCALE5 code from ORNL to define the energy spectrum and the decay of the source. We combined our computational results with experimental data to fully validate our computational schemes, tools and models. Results from our computational models will then be used with experiment to generate a mosaic of the radiation spectrum. Finally, we discuss follow-up studies that highlight response optimization efforts in designing, building, and testing an array of detectors with varying moderators/thicknesses tagged to specific responses predicted using 3-D radiation transport models to augment special nuclear materials detection.
3D electro-thermal Monte Carlo study of transport in confined silicon devices
NASA Astrophysics Data System (ADS)
Mohamed, Mohamed Y.
The simultaneous explosion of portable microelectronics devices and the rapid shrinking of microprocessor size have provided a tremendous motivation to scientists and engineers to continue the down-scaling of these devices. For several decades, innovations have allowed components such as transistors to be physically reduced in size, allowing the famous Moore's law to hold true. As these transistors approach the atomic scale, however, further reduction becomes less probable and practical. As new technologies overcome these limitations, they face new, unexpected problems, including the ability to accurately simulate and predict the behavior of these devices, and to manage the heat they generate. This work uses a 3D Monte Carlo (MC) simulator to investigate the electro-thermal behavior of quasi-one-dimensional electron gas (1DEG) multigate MOSFETs. In order to study these highly confined architectures, the inclusion of quantum correction becomes essential. To better capture the influence of carrier confinement, the electrostatically quantum-corrected full-band MC model has the added feature of being able to incorporate subband scattering. The scattering rate selection introduces quantum correction into carrier movement. In addition to the quantum effects, scaling introduces thermal management issues due to the surge in power dissipation. Solving these problems will continue to bring improvements in battery life, performance, and size constraints of future devices. We have coupled our electron transport Monte Carlo simulation to Aksamija's phonon transport so that we may accurately and efficiently study carrier transport, heat generation, and other effects at the transistor level. This coupling utilizes anharmonic phonon decay and temperature dependent scattering rates. One immediate advantage of our coupled electro-thermal Monte Carlo simulator is its ability to provide an accurate description of the spatial variation of self-heating and its effect on non
LATIS3D: The Gold Standard for Laser-Tissue-Interaction Modeling
London, R.A.; Makarewicz, A.M.; Kim, B.M.; Gentile, N.A.; Yang, Y.B.; Brlik, M.; Vincent, L.
2000-02-29
The goal of this LDRD project has been to create LATIS3D--the world's premier computer program for laser-tissue interaction modeling. The development was based on recent experience with the 2D LATIS code and the ASCI code, KULL. With LATIS3D, important applications in laser medical therapy were researched including dynamical calculations of tissue emulsification and ablation, photothermal therapy, and photon transport for photodynamic therapy. This project also enhanced LLNL's core competency in laser-matter interactions and high-energy-density physics by pushing simulation codes into new parameter regimes and by attracting external expertise. This will benefit both existing LLNL programs such as ICF and SBSS and emerging programs in medical technology and other laser applications.
3D Modeling of the ALICE Photoinjector Upgrade
McKenzie, J. W.; Militsyn, B. L.; Saveliev, Y. M.
2009-08-04
The injector for the ALICE machine (Accelerators and Lasers In Combined Experiments) at Daresbury Laboratory is based around a 350 kV DC photocathode electron gun. An upgrade is proposed to introduce a load-lock GaAs photocathode preparation facility to allow rapid transfer of photocathodes to the gun without breaking the vacuum system. In the current design this requires side-loading of the photocathodes into the cathode ball. An alternative is to relocate the ceramic insulator vertically which will allow back-loading and also backillumination of the photocathodes. 3D electrostatic simulations of the gun chamber are presented for both options along with 3D beam dynamic simulations for an off-axis photocathode, introduced to increase photocathode lifetime by reducing damage by ion backbombardment. Beam dynamic simulations are also presented for the entire injector beamline as well as for a proposed extension to the injector beamline to include a diagnostic section.
Optically directed molecular transport and 3D isoelectric positioning of amphoteric biomolecules
Hafeman, Dean G.; Harkins, James B.; Witkowski, Charles E.; Lewis, Nathan S.; Warmack, Robert J.; Brown, Gilbert M.; Thundat, Thomas
2006-01-01
We demonstrate the formation of charged molecular packets and their transport within optically created electrical force-field traps in a pH-buffered electrolyte. We call this process photoelectrophoretic localization and transport (PELT). The electrolyte is in contact with a photoconductive semiconductor electrode and a counterelectrode that are connected through an external circuit. A light beam directed to coordinates on the photoconductive electrode surface produces a photocurrent within the circuit and electrolyte. Within the electrolyte, the photocurrent creates localized force-field traps centered at the illuminated coordinates. Charged molecules, including polypeptides and proteins, electrophoretically accumulate into the traps and subsequently can be transported in the electrolyte by moving the traps over the photoconductive electrode in response to movement of the light beam. The molecules in a single trap can be divided into aliquots, and the aliquots can be directed along multiple routes simultaneously by using multiple light beams. This photoelectrophoretic transport of charged molecules by PELT resembles the electrostatic transport of electrons within force-field wells of solid-state charge-coupled devices. The molecules, however, travel in a liquid electrolyte rather than a solid. Furthermore, we have used PELT to position amphoteric biomolecules in three dimensions. A 3D pH gradient was created in an electrolyte medium by controlling the illumination position on a photoconductive anode where protons were generated electrolytically. Photoelectrophoretic transport of amphoteric molecules through the pH gradient resulted in accumulation of the molecules at their apparent 3D isoelectric coordinates in the medium. PMID:16618926
3D numerical model for NGC 6888 Nebula
NASA Astrophysics Data System (ADS)
Reyes-Iturbide, J.; Velázquez, P. F.; Rosado, M.
We present 3D numerical simulations of the NGC6888 nebula considering the proper motion and the evolution of the star, from the red supergiant (RSG) to the Wolf-Rayet (WR) phase. Our simulations reproduce the limb-brightened morphology observed in [OIII] and X-ray emission maps. The synthetic maps computed by the numerical simulations show filamentary and clumpy structures produced by instabilities triggered in the interaction between the WR wind and the RSG shell.
Estimation of gold potentials using 3D restoration modeling, Mount Pleasant Area, Western Australia
NASA Astrophysics Data System (ADS)
Mejia-Herrera, Pablo; Kakurina, Maria; Royer, Jean-Jacques
2015-04-01
A broad variety of gold-deposits are related to fault systems developed during a deformation event. Such discontinuities control the metals transport and allow the relatively high permeability necessary for the metals accumulation during the ore-deposits formation. However, some gold deposits formed during the same deformation event occur at locations far from the main faults. In those cases, the fracture systems are related with the rock heterogeneity that partially controls the damage development on the rock mass. A geo-mechanical 3D restoration modeling approach was used to simulate the strain developed during a stretching episode occurred in the Mount Pleasant region, Western Australia. Firstly a 3D solid-model was created from geological maps and interpreted structural cross-sections available on the studied region. The backward model was obtained flattening a stretching-representative reference surface selected from the lithology sequence. The deformation modeling was carried out on a 3D model built on Gocad/Skua and restored using a full geo-mechanical modeling based on a finite element method used to compute the volume restoration in a 600 m tetrahedral-mesh-resolution solid. The 3D structural restoration of the region was performed flattening surfaces using a flexural slip deformation style. Results show how the rock heterogeneity allows damages in locations far from the fault systems. The distant off-fault damage areas are located preferentially in lithological contacts and also follow the deformation trend of the region. Using a logistic regression method, it is shown that off-fault zones with high gold occurrences correlate spatially on locations with locally-high-gradient first deformational parameter, obtained from the restoration strain field. This contribution may provide some explanation for the presence of gold accumulations away from main fault systems, and the method could be used for inferring favorable areas in exploration surveys.
3-D model of ICME in the interplanetary medium
NASA Astrophysics Data System (ADS)
Borgazzi, A.; Lara, A.; Niembro, T.
2011-12-01
We developed a method that describes with simply geometry the coordinates of intersection between the leading edge of an ICME and the position of an arbitrary satellite. When a fast CME is ejected from the Sun to the interplanetary space in most of the cases drives a shock. As the CME moves in the corona and later in the interplanetary space more material is stacking in the front and edges of the ejecta. In a first approximation, it is possible to assume the shape of these structures, the CME and the stacked material as a cone of revolution, (the ice-cream model [Schwenn et al., (2005)]). The interface may change due to the interaction of the structure and the non-shocked material in front of the ICME but the original shape of a cone of revolution is preserved. We assume, in a three dimensional geometry, an ice-cream cone shape for the ICME and apply an analytical model for its transport in the interplanetary medium. The goal of the present method is to give the time and the intersection coordinates between the leading edge of the ICME and any satellite that may be in the path of the ICME. With this information we can modelate the travel of the ICME in the interplanetary space using STEREO data.
Testing the PV-Theta Mapping Technique in a 3-D CTM Model Simulation
NASA Technical Reports Server (NTRS)
Frith, Stacey M.
2004-01-01
Mapping lower stratospheric ozone into potential vorticity (PV)- potential temperature (Theta) coordinates is a common technique employed to analyze sparse data sets. Ozone transformed into a flow-following dynamical coordinate system is insensitive to meteorological variations. Therefore data from a wide range of times/locations can be compared, so long as the measurements were made in the same airmass (as defined by PV). Moreover, once a relationship between ozone and PV/Theta is established, a full 3D ozone field can be estimated from this relationship and the 3D analyzed PV field. However, ozone data mapped in this fashion can be hampered by noisy PV fields, or "mis-matches" in the resolution and/or exact location of the ozone and PV measurements. In this study, we investigate the PV-ozone relationship using output from a recent 50-year run of the Goddard 3D chemical transport model (CTM). Model constituents are transported using off-line dynamics from the finite volume general circulation model (FVGCM). By using the internally consistent model PV and ozone fields, we minimize noise due to mis-matching and resolution issues. We calculate correlations between model ozone and PV throughout the stratosphere, and test the sensitivity of the technique to initial data resolution. To do this we degrade the model data to that of various satellite instruments, then compare the mapped fields derived from the sub-sampled data to the full resolution model data. With these studies we can determine appropriate limits for the PV-theta mapping technique in latitude, altitude, and as a function of original data resolution.
Virtual and Printed 3D Models for Teaching Crystal Symmetry and Point Groups
ERIC Educational Resources Information Center
Casas, Lluís; Estop, Euge`nia
2015-01-01
Both, virtual and printed 3D crystal models can help students and teachers deal with chemical education topics such as symmetry and point groups. In the present paper, two freely downloadable tools (interactive PDF files and a mobile app) are presented as examples of the application of 3D design to study point-symmetry. The use of 3D printing to…
3D In Vitro Model for Breast Cancer Research Using Magnetic Levitation and Bioprinting Method.
Leonard, Fransisca; Godin, Biana
2016-01-01
Tumor microenvironment composition and architecture are known as a major factor in orchestrating the tumor growth and its response to various therapies. In this context, in vivo studies are necessary to evaluate the responses. However, while tumor cells can be of human origin, tumor microenvironment in the in vivo models is host-based. On the other hand, in vitro studies in a flat monoculture of tumor cells (the most frequently used in vitro tumor model) are unable to recapitulate the complexity of tumor microenvironment. Three-dimensional (3D) in vitro cell cultures of tumor cells have been proven to be an important experimental tool in understanding mechanisms of tumor growth, response to therapeutics, and transport of nutrients/drugs. We have recently described a novel tool to create 3D co-cultures of tumor cells and cells in the tumor microenvironment. Our method utilizes magnetic manipulation/levitation of the specific ratios of tumor cells and cells in the tumor microenvironment (from human or animal origin) aiding in the formation of tumor spheres with defined cellular composition and density, as quickly as within 24 h. This chapter describes the experimental protocols developed to model the 3D structure of the cancer environment using the above method. PMID:26820961
ODTLES : a model for 3D turbulent flow based on one-dimensional turbulence modeling concepts.
McDermott, Randy; Kerstein, Alan R.; Schmidt, Rodney Cannon
2005-01-01
This report describes an approach for extending the one-dimensional turbulence (ODT) model of Kerstein [6] to treat turbulent flow in three-dimensional (3D) domains. This model, here called ODTLES, can also be viewed as a new LES model. In ODTLES, 3D aspects of the flow are captured by embedding three, mutually orthogonal, one-dimensional ODT domain arrays within a coarser 3D mesh. The ODTLES model is obtained by developing a consistent approach for dynamically coupling the different ODT line sets to each other and to the large scale processes that are resolved on the 3D mesh. The model is implemented computationally and its performance is tested and evaluated by performing simulations of decaying isotropic turbulence, a standard turbulent flow benchmarking problem.
Numerical modelling of gravel unconstrained flow experiments with the DAN3D and RASH3D codes
NASA Astrophysics Data System (ADS)
Sauthier, Claire; Pirulli, Marina; Pisani, Gabriele; Scavia, Claudio; Labiouse, Vincent
2015-12-01
Landslide continuum dynamic models have improved considerably in the last years, but a consensus on the best method of calibrating the input resistance parameter values for predictive analyses has not yet emerged. In the present paper, numerical simulations of a series of laboratory experiments performed at the Laboratory for Rock Mechanics of the EPF Lausanne were undertaken with the RASH3D and DAN3D numerical codes. They aimed at analysing the possibility to use calibrated ranges of parameters (1) in a code different from that they were obtained from and (2) to simulate potential-events made of a material with the same characteristics as back-analysed past-events, but involving a different volume and propagation path. For this purpose, one of the four benchmark laboratory tests was used as past-event to calibrate the dynamic basal friction angle assuming a Coulomb-type behaviour of the sliding mass, and this back-analysed value was then used to simulate the three other experiments, assumed as potential-events. The computational findings show good correspondence with experimental results in terms of characteristics of the final deposits (i.e., runout, length and width). Furthermore, the obtained best fit values of the dynamic basal friction angle for the two codes turn out to be close to each other and within the range of values measured with pseudo-dynamic tilting tests.
Advances in 3D electromagnetic finite element modeling
Nelson, E.M.
1997-08-01
Numerous advances in electromagnetic finite element analysis (FEA) have been made in recent years. The maturity of frequency domain and eigenmode calculations, and the growth of time domain applications is briefly reviewed. A high accuracy 3D electromagnetic finite element field solver employing quadratic hexahedral elements and quadratic mixed-order one-form basis functions will also be described. The solver is based on an object-oriented C++ class library. Test cases demonstrate that frequency errors less than 10 ppm can be achieved using modest workstations, and that the solutions have no contamination from spurious modes. The role of differential geometry and geometrical physics in finite element analysis is also discussed.
Computational approaches to 3D modeling of RNA.
Laing, Christian; Schlick, Tamar
2010-07-21
Many exciting discoveries have recently revealed the versatility of RNA and its importance in a variety of functions within the cell. Since the structural features of RNA are of major importance to their biological function, there is much interest in predicting RNA structure, either in free form or in interaction with various ligands, including proteins, metabolites and other molecules. In recent years, an increasing number of researchers have developed novel RNA algorithms for predicting RNA secondary and tertiary structures. In this review, we describe current experimental and computational advances and discuss recent ideas that are transforming the traditional view of RNA folding. To evaluate the performance of the most recent RNA 3D folding algorithms, we provide a comparative study in order to test the performance of available 3D structure prediction algorithms for an RNA data set of 43 structures of various lengths and motifs. We find that the algorithms vary widely in terms of prediction quality across different RNA lengths and topologies; most predictions have very large root mean square deviations from the experimental structure. We conclude by outlining some suggestions for future RNA folding research. PMID:21399271
Domain Decomposition PN Solutions to the 3D Transport Benchmark over a Range in Parameter Space
NASA Astrophysics Data System (ADS)
Van Criekingen, S.
2014-06-01
The objectives of this contribution are twofold. First, the Domain Decomposition (DD) method used in the parafish parallel transport solver is re-interpreted as a Generalized Schwarz Splitting as defined by Tang [SIAM J Sci Stat Comput, vol.13 (2), pp. 573-595, 1992]. Second, parafish provides spherical harmonic (i.e., PN) solutions to the NEA benchmark suite for 3D transport methods and codes over a range in parameter space. To the best of the author's knowledge, these are the first spherical harmonic solutions provided for this demanding benchmark suite. They have been obtained using 512 CPU cores of the JuRoPa machine installed at the Jülich Computing Center (Germany).
Numerical modeling of Tibetan Plateau formation: Thin-sheet versus fully 3D models
NASA Astrophysics Data System (ADS)
Lechmann, S. M.; Schmalholz, S. M.; Kaus, B. J. P.
2009-04-01
Knowledge about the tectonic evolution of the Tibetan Plateau is still incomplete and many open questions remain concerning the deformation style of the crustal thickening, causing the abnormally high elevation of the Tibetan Plateau. Different models have been suggested explaining the crustal thickening by (1) homogeneous, continuous deformation using thin-sheet models, (2) discrete movement along thrusts developing crustal wedges and (3) lateral crustal flow due to pressure gradients resulting from topography. Most existing models are not fully three-dimensional (3D) models (e.g. thin-sheet models) and assume a certain deformation style a priori, which makes it difficult to judge the applicability of such constrained models to the formation of the Tibetan Plateau. We present a comparison of deformation styles during continent indentation resulting from a fully 3D numerical model and a thin-sheet model. The rheology for both models is power-law. The 3D model consists of four layers representing a simplified lithosphere: strong upper crust, weak lower crust, strong upper mantle and weak lower mantle. From the effective viscosity distribution of the 3D model a vertically averaged effective viscosity is calculated and used for the thin-sheet model to make direct comparisons between the two models. Simulating indentation is achieved by assigning free slip at one lateral side of the model, and fixing two other sides. The boundary at which indentation is taking place, exhibits a tripartite velocity profile: Next to the free slip side a section with constant horizontal velocity is applied. The velocity then gradually decreases towards zero, applying a cosine-function. The last section of the indenting boundary next to the fixed side is also fixed. The 3D model additionally exhibits a free surface and a bottom boundary allowing free slip. The 3D code employs the finite element method with a mixed velocity-pressure formulation to simulate incompressible flow. A Lagrangian
NASA Astrophysics Data System (ADS)
Brasebin, M.; Perret, J.; Mustière, S.; Weber, C.
2012-10-01
The increased availability of 3D urban data reflects a growing interest in 3D spatial analysis. As 3D spatial analysis often uses complex 3D data, studies of the potential gains of using more detailed 3D urban databases for specific uses is an important issue. First, more complex data implies an increase in time and memory usage for the analysis (and calls for more research on the efficiency of the algorithms used). Second, detailed 3D urban data are complex to produce, expensive and it is important to be well informed in order to decide whether of not to invest in such data. Currently, many studies have been led about the fitness for use of 2D data but they are very scarce concerning 3D data. This article presents a method to determine the influence of 3D modeling on the results of 3D analysis by isolating the potential sources of errors (such as roof modeling and geometric accuracy). This method is applied on two 3D datasets (LOD1 and LOD2) and a 3D indicator (the sky view factor or SVF). The results show that the significant influence of roof modeling is globally compensated by the difference in geometric modeling but that important local variations are noticed. Nevertheless, for 75% of the SVF processed the difference between the results using these two databases is lower than 2%.
Coupled 1D-3D hydrodynamic modelling, with application to the Pearl River Delta
NASA Astrophysics Data System (ADS)
Twigt, Daniel J.; de Goede, Erik D.; Zijl, Firmijn; Schwanenberg, Dirk; Chiu, Alex Y. W.
2009-12-01
modelling of complex coastal waters and river network systems, whilst the advantages of both systems are maintained and used in an optimal and computationally efficient way. The coupled 1D-3D system is used to model the flows in the Pearl River Delta (Guangdong, China), which are determined by the interaction of the upstream network of the Pearl River and the open waters of the South China Sea. The highly complex upstream river network is modelled in 1D, simulating river discharges for the dry and wet monsoon periods. The 3D coastal model simulates the flow due to the external (ocean) periodic tidal forcing, the salinity distribution for both dry and wet seasons, as well as residual water levels (sea level anomalies) originating from the South China Sea. The model is calibrated and its performance extensively assessed against field measurements, resulting in a mean root mean square (RMS) error of below 6% for water levels over the entire Pearl River Delta. The model also represents both the discharge distribution over the river network and salinity transport processes with good accuracy, resolving the discharge distribution over the main branches of the river network within 5% of reported annual mean values and RMS errors for salinity in the range of 2 ppt (dry season) to 5 ppt (wet season).
3D self-consistent percolative model for networks of randomly aligned carbon nanotubes
NASA Astrophysics Data System (ADS)
Colasanti, S.; Deep Bhatt, V.; Abdellah, A.; Lugli, P.
2015-10-01
A numerical percolative model for simulations of random networks of carbon nanotubes is presented. This algorithm takes into account the real 3D nature of these networks, allowing for a better understanding of their electrical properties. The nanotubes are modeled as non-rigid bendable cylinders with geometrical properties derived according to some statistical distributions inferred from the experiments. For the transport mechanisms we refer to the theory of one-dimensional ballistic channels which is based on the computation of the density of states. The behavior of the entire network is then simulated by coupling a SPICE program with an iterative algorithm that calculates self-consistently the electrostatic potential and the current flow in each node of the network. We performed several simulations on the resistivity of networks with different thicknesses and over different simulation domains. Our results confirm the percolative nature of the electrical transport, which are more pronounced in films close to their percolation threshold.
A Deformable Generic 3D Model of Haptoral Anchor of Monogenean
Teo, Bee Guan; Dhillon, Sarinder Kaur; Lim, Lee Hong Susan
2013-01-01
In this paper, a digital 3D model which allows for visualisation in three dimensions and interactive manipulation is explored as a tool to help us understand the structural morphology and elucidate the functions of morphological structures of fragile microorganisms which defy live studies. We developed a deformable generic 3D model of haptoral anchor of dactylogyridean monogeneans that can subsequently be deformed into different desired anchor shapes by using direct manipulation deformation technique. We used point primitives to construct the rectangular building blocks to develop our deformable 3D model. Point primitives are manually marked on a 2D illustration of an anchor on a Cartesian graph paper and a set of Cartesian coordinates for each point primitive is manually extracted from the graph paper. A Python script is then written in Blender to construct 3D rectangular building blocks based on the Cartesian coordinates. The rectangular building blocks are stacked on top or by the side of each other following their respective Cartesian coordinates of point primitive. More point primitives are added at the sites in the 3D model where more structural variations are likely to occur, in order to generate complex anchor structures. We used Catmull-Clark subdivision surface modifier to smoothen the surface and edge of the generic 3D model to obtain a smoother and more natural 3D shape and antialiasing option to reduce the jagged edges of the 3D model. This deformable generic 3D model can be deformed into different desired 3D anchor shapes through direct manipulation deformation technique by aligning the vertices (pilot points) of the newly developed deformable generic 3D model onto the 2D illustrations of the desired shapes and moving the vertices until the desire 3D shapes are formed. In this generic 3D model all the vertices present are deployed for displacement during deformation. PMID:24204903
A deformable generic 3D model of haptoral anchor of Monogenean.
Teo, Bee Guan; Dhillon, Sarinder Kaur; Lim, Lee Hong Susan
2013-01-01
In this paper, a digital 3D model which allows for visualisation in three dimensions and interactive manipulation is explored as a tool to help us understand the structural morphology and elucidate the functions of morphological structures of fragile microorganisms which defy live studies. We developed a deformable generic 3D model of haptoral anchor of dactylogyridean monogeneans that can subsequently be deformed into different desired anchor shapes by using direct manipulation deformation technique. We used point primitives to construct the rectangular building blocks to develop our deformable 3D model. Point primitives are manually marked on a 2D illustration of an anchor on a Cartesian graph paper and a set of Cartesian coordinates for each point primitive is manually extracted from the graph paper. A Python script is then written in Blender to construct 3D rectangular building blocks based on the Cartesian coordinates. The rectangular building blocks are stacked on top or by the side of each other following their respective Cartesian coordinates of point primitive. More point primitives are added at the sites in the 3D model where more structural variations are likely to occur, in order to generate complex anchor structures. We used Catmull-Clark subdivision surface modifier to smoothen the surface and edge of the generic 3D model to obtain a smoother and more natural 3D shape and antialiasing option to reduce the jagged edges of the 3D model. This deformable generic 3D model can be deformed into different desired 3D anchor shapes through direct manipulation deformation technique by aligning the vertices (pilot points) of the newly developed deformable generic 3D model onto the 2D illustrations of the desired shapes and moving the vertices until the desire 3D shapes are formed. In this generic 3D model all the vertices present are deployed for displacement during deformation. PMID:24204903
An unstaggered constrained transport method for the 3D ideal magnetohydrodynamic equations
NASA Astrophysics Data System (ADS)
Helzel, Christiane; Rossmanith, James A.; Taetz, Bertram
2011-05-01
Numerical methods for solving the ideal magnetohydrodynamic (MHD) equations in more than one space dimension must either confront the challenge of controlling errors in the discrete divergence of the magnetic field, or else be faced with nonlinear numerical instabilities. One approach for controlling the discrete divergence is through a so-called constrained transport method, which is based on first predicting a magnetic field through a standard finite volume solver, and then correcting this field through the appropriate use of a magnetic vector potential. In this work we develop a constrained transport method for the 3D ideal MHD equations that is based on a high-resolution wave propagation scheme. Our proposed scheme is the 3D extension of the 2D scheme developed by Rossmanith [J.A. Rossmanith, An unstaggered, high-resolution constrained transport method for magnetohydrodynamic flows, SIAM J. Sci. Comput. 28 (2006) 1766], and is based on the high-resolution wave propagation method of Langseth and LeVeque [J.O. Langseth, R.J. LeVeque, A wave propagation method for threedimensional hyperbolic conservation laws, J. Comput. Phys. 165 (2000) 126]. In particular, in our extension we take great care to maintain the three most important properties of the 2D scheme: (1) all quantities, including all components of the magnetic field and magnetic potential, are treated as cell-centered; (2) we develop a high-resolution wave propagation scheme for evolving the magnetic potential; and (3) we develop a wave limiting approach that is applied during the vector potential evolution, which controls unphysical oscillations in the magnetic field. One of the key numerical difficulties that is novel to 3D is that the transport equation that must be solved for the magnetic vector potential is only weakly hyperbolic. In presenting our numerical algorithm we describe how to numerically handle this problem of weak hyperbolicity, as well as how to choose an appropriate gauge condition. The
3D simulation studies of tokamak plasmas using MHD and extended-MHD models
Park, W.; Chang, Z.; Fredrickson, E.; Fu, G.Y.
1996-12-31
The M3D (Multi-level 3D) tokamak simulation project aims at the simulation of tokamak plasmas using a multi-level tokamak code package. Several current applications using MHD and Extended-MHD models are presented; high-{beta} disruption studies in reversed shear plasmas using the MHD level MH3D code, {omega}{sub *i} stabilization and nonlinear island saturation of TAE mode using the hybrid particle/MHD level MH3D-K code, and unstructured mesh MH3D{sup ++} code studies. In particular, three internal mode disruption mechanisms are identified from simulation results which agree which agree well with experimental data.
Holford, D.J.
1994-01-01
This document is a user`s manual for the Rn3D finite element code. Rn3D was developed to simulate gas flow and radon transport in variably saturated, nonisothermal porous media. The Rn3D model is applicable to a wide range of problems involving radon transport in soil because it can simulate either steady-state or transient flow and transport in one-, two- or three-dimensions (including radially symmetric two-dimensional problems). The porous materials may be heterogeneous and anisotropic. This manual describes all pertinent mathematics related to the governing, boundary, and constitutive equations of the model, as well as the development of the finite element equations used in the code. Instructions are given for constructing Rn3D input files and executing the code, as well as a description of all output files generated by the code. Five verification problems are given that test various aspects of code operation, complete with example input files, FORTRAN programs for the respective analytical solutions, and plots of model results. An example simulation is presented to illustrate the type of problem Rn3D is designed to solve. Finally, instructions are given on how to convert Rn3D to simulate systems other than radon, air, and water.
3D multi-scale analysis of coupled heat and moisture transport and its parallel implementation
NASA Astrophysics Data System (ADS)
Kruis, Jaroslav
2016-06-01
Parallel implementation of two-scale model of coupled heat and moisture transport is described. The coupled heat and moisture transport is based on the Künzel model. Motivation for the two-scale analysis comes from the requirement to describe distribution of the relative humidity and temperature in historical masonry structures.
Reconstruction of 3D structure using stochastic methods: morphology and transport properties
NASA Astrophysics Data System (ADS)
Karsanina, Marina; Gerke, Kirill; Čapek, Pavel; Vasilyev, Roman; Korost, Dmitry; Skvortsova, Elena
2013-04-01
One of the main factors defining numerous flow phenomena in rocks, soils and other porous media, including fluid and solute movements, is pore structure, e.g., pore sizes and their connectivity. Numerous numerical methods were developed to quantify single and multi-phase flow in such media on microscale. Among most popular ones are: 1) a wide range of finite difference/element/volume solutions of Navier-Stokes equations and its simplifications; 2) lattice-Boltzmann method; 3) pore-network models, among others. Each method has some advantages and shortcomings, so that different research teams usually utilize more than one, depending on the study case. Recent progress in 3D imaging of internal structure, e.g., X-ray tomography, FIB-SEM and confocal microscopy, made it possible to obtain digitized input pore parameters for such models, however, a trade-off between resolution and sample size is usually unavoidable. There are situations then only standard two-dimensional information of porous structure is known due to tomography high cost or resolution limitations. However, physical modeling on microscale requires 3D information. There are three main approaches to reconstruct (using 2D cut(s) or some other limited information/properties) porous media: 1) statistical methods (correlation functions and simulated annealing, multi-point statistics, entropy methods), 2) sequential methods (sphere or other granular packs) and 3) morphological methods. Stochastic reconstructions using correlation functions possess some important advantage - they provide a statistical description of the structure, which is known to have relationships with all physical properties. In addition, this method is more flexible for other applications to characterize porous media. Taking different 3D scans of natural and artificial porous materials (sandstones, soils, shales, ceramics) we choose some 2D cut/s as sources of input correlation functions. Based on different types of correlation functions
Developing and Testing a 3d Cadastral Data Model a Case Study in Australia
NASA Astrophysics Data System (ADS)
Aien, A.; Kalantari, M.; Rajabifard, A.; Williamson, I. P.; Shojaei, D.
2012-07-01
Population growth, urbanization and industrialization place more pressure on land use with the need for increased space. To extend the use and functionality of the land, complex infrastructures are being built, both vertically and horizontally, layered and stacked. These three-dimensional (3D) developments affect the interests (Rights, Restrictions, and Responsibilities (RRRs)) attached to the underlying land. A 3D cadastre will assist in managing the effects of 3D development on a particular extent of land. There are many elements that contribute to developing a 3D cadastre, such as existing of 3D property legislations, 3D DBMS, 3D visualization. However, data modelling is one of the most important elements of a successful 3D cadastre. As architectural models of houses and high rise buildings help their users visualize the final product, 3D cadastre data model supports 3D cadastre users to understand the structure or behavior of the system and has a template that guides them to construct and implement the 3D cadastre. Many jurisdictions, organizations and software developers have built their own cadastral data model. Land Administration Domain Model (DIS-ISO 19152, The Netherlands) and ePlan (Intergovernmental Committee on Surveying and Mapping, Australia) are examples of existing data models. The variation between these data models is the result of different attitudes towards cadastres. However, there is a basic common thread among them all. Current cadastral data models use a 2D land-parcel concept and extend it to support 3D requirements. These data models cannot adequately manage and represent the spatial extent of 3D RRRs. Most of the current cadastral data models have been influenced by a very broad understanding of 3D cadastral concepts because better clarity in what needs to be represented and analysed in the cadastre needs to be established. This paper presents the first version of a 3D Cadastral Data Model (3DCDM_Version 1.0). 3DCDM models both the legal
Implementation of algebraic stress models in a general 3-D Navier-Stokes method (PAB3D)
NASA Technical Reports Server (NTRS)
Abdol-Hamid, Khaled S.
1995-01-01
A three-dimensional multiblock Navier-Stokes code, PAB3D, which was developed for propulsion integration and general aerodynamic analysis, has been used extensively by NASA Langley and other organizations to perform both internal (exhaust) and external flow analysis of complex aircraft configurations. This code was designed to solve the simplified Reynolds Averaged Navier-Stokes equations. A two-equation k-epsilon turbulence model has been used with considerable success, especially for attached flows. Accurate predicting of transonic shock wave location and pressure recovery in separated flow regions has been more difficult. Two algebraic Reynolds stress models (ASM) have been recently implemented in the code that greatly improved the code's ability to predict these difficult flow conditions. Good agreement with Direct Numerical Simulation (DNS) for a subsonic flat plate was achieved with ASM's developed by Shih, Zhu, and Lumley and Gatski and Speziale. Good predictions were also achieved at subsonic and transonic Mach numbers for shock location and trailing edge boattail pressure recovery on a single-engine afterbody/nozzle model.
Ground and Structure Deformation 3d Modelling with a Tin Based Property Model
NASA Astrophysics Data System (ADS)
TIAN, T.; Zhang, J.; Jiang, W.
2013-12-01
With the development of 3D( three-dimensional) modeling and visualization, more and more 3D tectonics are used to assist the daily work in Engineering Survey, in which the prediction of deformation field in strata and structure induced by underground construction is an essential part. In this research we developed a TIN (Triangulated Irregular Network) based property model for the 3D (three dimensional) visualization of ground deformation filed. By record deformation vector for each nodes, the new model can express the deformation with geometric-deformation-style by drawing each node in its new position and deformation-attribute-distribution-style by drawing each node in the color correspond with its deformation attribute at the same time. Comparing with the volume model based property model, this new property model can provide a more precise geometrical shape for structure objects. Furthermore, by recording only the deformation data of the user-interested 3d surface- such as the ground surface or the underground digging surface, the new property model can save a lot of space, which makes it possible to build the deformation filed model of a much more large scale. To construct the models of deformation filed based on TIN model, the refinement of the network is needed to increase the nodes number, which is necessary to express the deformation filed with a certain resolution. The TIN model refinement is a process of sampling the 3D deformation field values on points on the TIN surface, for which we developed a self-adapting TIN refinement method. By set the parameter of the attribute resolution, this self-adapting method refines the input geometric-expressing TIN model by adding more vertexes and triangles where the 3D deformation filed changing faster. Comparing with the even refinement method, the self-adapting method can generate a refined TIN model with nodes counted less by two thirds. Efficiency Comparison between Self-adapting Refinement Method and Even
Detection of Disease Symptoms on Hyperspectral 3d Plant Models
NASA Astrophysics Data System (ADS)
Roscher, Ribana; Behmann, Jan; Mahlein, Anne-Katrin; Dupuis, Jan; Kuhlmann, Heiner; Plümer, Lutz
2016-06-01
We analyze the benefit of combining hyperspectral images information with 3D geometry information for the detection of Cercospora leaf spot disease symptoms on sugar beet plants. Besides commonly used one-class Support Vector Machines, we utilize an unsupervised sparse representation-based approach with group sparsity prior. Geometry information is incorporated by representing each sample of interest with an inclination-sorted dictionary, which can be seen as an 1D topographic dictionary. We compare this approach with a sparse representation based approach without geometry information and One-Class Support Vector Machines. One-Class Support Vector Machines are applied to hyperspectral data without geometry information as well as to hyperspectral images with additional pixelwise inclination information. Our results show a gain in accuracy when using geometry information beside spectral information regardless of the used approach. However, both methods have different demands on the data when applied to new test data sets. One-Class Support Vector Machines require full inclination information on test and training data whereas the topographic dictionary approach only need spectral information for reconstruction of test data once the dictionary is build by spectra with inclination.
NASA Astrophysics Data System (ADS)
Kincaid, C. R.; MacDougall, J. G.; Druken, K. A.; Fischer, K. M.
2010-12-01
Understanding patterns in plate scale mantle flow in subduction zones is key to models of thermal structure, dehydration reactions, volatile distributions and magma generation and transport in convergent margins. Different patterns of flow in the mantle wedge can generate distinct signatures in seismological observables. Observed shear wave fast polarization directions in several subduction zones are inconsistent with predictions of simple 2-D wedge corner flow. Geochemical signatures in a number of subduction zones also indicate 3-D flow and entrainment patterns in the wedge. We report on a series of laboratory experiments on subduction driven flow to characterize spatial and temporal variability in 3-D patterns in flow and shear-induced finite strain. Cases focus on how rollback subduction, along-strike dip changes in subducting plates and evolving gaps or tears in subduction zones control temporal-spatial patterns in 3-D wedge flow. Models utilize a glucose working fluid with a temperature dependent viscosity to represent the upper 2000 km of the mantle. Subducting lithosphere is modeled with two rubber-reinforced continuous belts. Belts pass around trench and upper/lower mantle rollers. The deeper rollers can move laterally to allow for time varying dip angle. Each belt has independent speed control and dip adjustment, allowing for along-strike changes in convergence rate and the evolution of slab gaps. Rollback is modeled using a translation system to produce either uniform and asymmetric lateral trench motion. Neutral density finite strain markers are distributed throughout the fluid and used as proxies for tracking the evolution of anisotropy through space and time in the evolving flow fields. Particle image velocimetry methods are also used to track time varying 3-D velocity fields for directly calculating anisotropy patterns. Results show that complex plate motions (rollback, steepening) and morphologies (gaps) in convergent margins produce flows with
Incorporating preferential flow into a 3D model of a forested headwater catchment
NASA Astrophysics Data System (ADS)
Glaser, Barbara; Jackisch, Conrad; Hopp, Luisa; Pfister, Laurent; Klaus, Julian
2016-04-01
Preferential flow plays an important role for water flow and solute transport. The inclusion of preferential flow, for example with dual porosity or dual permeability approaches, is a common feature in transport simulations at the plot scale. But at hillslope and catchment scales, incorporation of macropore and fracture flow into distributed hydrologic 3D models is rare, often due to limited data availability for model parameterisation. In this study, we incorporated preferential flow into an existing 3D integrated surface subsurface hydrologic model (HydroGeoSphere) of a headwater region (6 ha) of the forested Weierbach catchment in western Luxembourg. Our model philosophy was a strong link between measured data and the model setup. The model setup we used previously had been parameterised and validated based on various field data. But existing macropores and fractures had not been considered in this initial model setup. The multi-criteria validation revealed a good model performance but also suggested potential for further improvement by incorporating preferential flow as additional process. In order to pursue the data driven model philosophy for the implementation of preferential flow, we analysed the results of plot scale bromide sprinkling and infiltration experiments carried out in the vicinity of the Weierbach catchment. Three 1 sqm plots were sprinkled for one hour and excavated one day later for bromide depth profile sampling. We simulated these sprinkling experiments at the soil column scale, using the parameterisation of the base headwater model extended by a second permeability domain. Representing the bromide depth profiles was successful without changing this initial parameterisation. Moreover, to explain the variability between the three bromide depth profiles it was sufficient to adapt the dual permeability properties, indicating the spatial heterogeneity of preferential flow. Subsequently, we incorporated the dual permeability simulation in the
ReefSAM - Reef Sedimentary Accretion Model: A new 3D coral reef evolution model/simulator
NASA Astrophysics Data System (ADS)
Barrett, Samuel; Webster, Jody
2013-04-01
Coral reefs show characteristic morphological patterns (e.g. coral dominated margins with detrital carbonate dominated lagoons/back-reef) and temporal development (e.g. Hopley et al. 2007). While the processes which lead to predictable patterns on a range of scales have been discussed qualitatively, a full quantitative understanding of the range of processes and parameters involved requires modelling. Previous attempts to model complex Holocene reef systems (i.e. One Tree Reef, GBR - Barrett and Webster 2012) using a carbonate stratigraphic forward model (Carbonate3D - Warrlich et al. 2002) identified a number of important but unsimulated processes and potential model improvements. ReefSAM has been written from scratch in Matlab using these findings and experiences from using Carbonate3D. It simulates coralgal accretion and carbonate sand production and transport. Specific improvements include: 1. a more complex hydrodynamic model based on wave refraction and incorporating vertical (depth) and lateral (substrate dependent) variations in transport energy and erosion. 2. a complex reef growth model incorporating depth, wave energy/turbidity and substrate composition. 3. Paleo-water depth, paleo-wave energy and bio-zone (combination of paleo-water depth and wave energy) model outputs allowing coralgal habitat changes through time and space to be simulated and compared to observational data. The model is compared to the well studied One Tree Reef - tests similar to those undertaken in Barrett and Webster 2012 with Carbonate3D are presented. Model development coincides with plans for further intensive drilling at One Tree Reef (mid 2013) providing an opportunity to test the model predictively. The model is still in active development. References: Barrett, S.J., Webster, J.M.,2012. Holocene evolution of the Great Barrier Reef: Insights from 3D numerical modelling. Sedimentary Geology 265-266, 56-71. Warrlich, G.M.D., Waltham, D.A., Bosence D.W.J., 2002. Quantifying the
NASA Astrophysics Data System (ADS)
Klimeck, Gerhard
2001-03-01
The quantum mechanical functionality of commercially pursued heterostructure devices such as resonant tunneling diodes (RTDs), quantum well infrared photodetectors, and quantum well lasers are enabled by material variations on an atomic scale. The creation of these heterostructure devices is realized in a vast design space of material compositions, layer thicknesses and doping profiles. The full experimental exploration of this design space is unfeasible and a reliable design tool is needed. The Nanoelectronic Modeling tool (NEMO) is one of the first commercial grade attempts for such a modeling tool. NEMO was developed as a general-purpose quantum mechanics-based 1-D device design and analysis tool from 1993-97 by the Central Research Laboratory of Texas Instruments (later Raytheon Systems). NEMO enables(R. Lake, G. Klimeck, R. C. Bowen, and D. Jovanovic, J. Appl. Phys. 81), 7845 (1997). the fundamentally sound inclusion of the required(G. Klimeck et al.), in the 1997 55th Annual Device Research Conference Digest, (IEEE, NJ, 1997), p. 92^,(R. C. Bowen et al.), J. Appl. Phys 81, 3207 (1997). physics: bandstructure, scattering, and charge self-consistency based on the non-equilibrium Green function approach. A new class of devices which require full 3-D quantum mechanics based models is starting to emerge: quantum dots, or in general semiconductor based deca-nano devices. We are currently building a 3-D modeling tool based on NEMO to include the important physics to understand electronic stated in such superscaled structures. This presentation will overview various facets of the NEMO 1-D tool such electron transport physics in RTDs, numerical technology, software engineering and graphical user interface. The lessons learned from that work are now entering the 3D>NEMO 3-D development and first results using the NEMO 3-D prototype will be shown. More information about
A 3-D nonisothermal flow simulation and pulling force model for injection pultrusion processes
NASA Astrophysics Data System (ADS)
Mustafa, Ibrahim
1998-12-01
Injected Pultrusion (IP) is an efficient way of producing high quality, low cost, high volume and constant cross-section polymeric composites. This process has been developed recently, and the efforts to optimize it are still underway. This work is related to the development of a 3-D non-isothermal flow model for the IP processes. The governing equations for transport of mass, momentum and, energy are formulated by using a local volume averaging approach, and the Finite Element/Control Volume method is used to solve the system of equations numerically. The chemical species balance equation is solved in the Lagrangian frame of reference whereas the energy equation is solved using Galerkin, SU (Streamline Upwind), and SUPG (Streamline Upwind Petrov Galerkin) approaches. By varying degrees of freedom and the flow rates of the resin, it is shown that at high Peclet numbers the SUPG formulation performs better than the SU and the Galerkin methods in all cases. The 3-D model predictions for degree of cure and temperature are compared with a one dimensional analytical solution and the results are found satisfactory. Moreover, by varying the Brinkman Number, it is shown that the effect of viscous dissipation is insignificant. The 3-D flow simulations have been carried out for both thin and thick parts and the results are compared with the 2-D model. It is shown that for thick parts 2-D simulations render erroneous results. The effect of changing permeability on the flow fronts is also addressed. The effect of increasing taper angle on the model prediction is also investigated. A parametric study is conducted to isolate optimum conditions for both isothermal and non-isothermal cases using a straight rectangular die and a die with a tapered inlet. Finally, a simple pulling force model is developed and the pulling force required to pull the carbon-epoxy fiber resin system is estimated for dies of varying tapered inlet.
Coupling 2-D cylindrical and 3-D x-y-z transport computations
Abu-Shumays, I.K.; Yehnert, C.E.; Pitcairn, T.N.
1998-06-30
This paper describes a new two-dimensional (2-D) cylindrical geometry to three-dimensional (3-D) rectangular x-y-z splice option for multi-dimensional discrete ordinates solutions to the neutron (photon) transport equation. Of particular interest are the simple transformations developed and applied in order to carry out the required spatial and angular interpolations. The spatial interpolations are linear and equivalent to those applied elsewhere. The angular interpolations are based on a high order spherical harmonics representation of the angular flux. Advantages of the current angular interpolations over previous work are discussed. An application to an intricate streaming problem is provided to demonstrate the advantages of the new method for efficient and accurate prediction of particle behavior in complex geometries.
3D Structure of Saharan Dust Transport Towards Europe as Seen by CALIPSO
NASA Astrophysics Data System (ADS)
Marinou, Eleni; Amiridis, Vassilis; Tsekeri, Alexandra; Solomos, Stavros; Kokkalis, Panos; Proestakis, Emmanouil; Kottas, Michael; Binietoglou, Ioannis; Zanis, Prodromos; Kazadzis, Stelios; Wandinger, Ulla; Ansmann, Albert
2016-06-01
We present a 3D multi-year monthly mean climatology of Saharan dust advection over Europe using an area-optimized pure dust CALIPSO product. The product has been developed by applying EARLINET-measured dust lidar ratios and depolarization-based dust discrimination methods and it is shown to have a very good agreement in terms of AOD when compared to AERONET over Europe/North Africa and MODIS over Mediterranean. The processing of such purely observational data reveals the certain seasonal patterns of dust transportation towards Europe and the Atlantic Ocean. The physical and optical properties of the dust layer are identified for several areas near the Saharan sources, over the Mediterranean and over continental Europe.
Distributed network of integrated 3D sensors for transportation security applications
NASA Astrophysics Data System (ADS)
Hejmadi, Vic; Garcia, Fred
2009-05-01
The US Port Security Agency has strongly emphasized the needs for tighter control at transportation hubs. Distributed arrays of miniature CMOS cameras are providing some solutions today. However, due to the high bandwidth required and the low valued content of such cameras (simple video feed), large computing power and analysis algorithms as well as control software are needed, which makes such an architecture cumbersome, heavy, slow and expensive. We present a novel technique by integrating cheap and mass replicable stealth 3D sensing micro-devices in a distributed network. These micro-sensors are based on conventional structures illumination via successive fringe patterns on the object to be sensed. The communication bandwidth between each sensor remains very small, but is of very high valued content. Key technologies to integrate such a sensor are digital optics and structured laser illumination.
Dynamics of free subduction from 3-D boundary element modeling
NASA Astrophysics Data System (ADS)
Li, Zhong-Hai; Ribe, Neil M.
2012-06-01
In order better to understand the physical mechanisms underlying free subduction, we perform three-dimensional boundary-element numerical simulations of a dense fluid sheet with thickness h and viscosity η2 sinking in an `ambient mantle' with viscosity η1. The mantle layer is bounded above by a traction-free surface, and is either (1) infinitely deep or (2) underlain by a rigid boundary at a finite depth H + d, similar to the typical geometry used in laboratory experiments. Instantaneous solutions in configuration (1) show that the sheet's dimensionless `stiffness' S determines whether the slab's sinking speed is controlled by the viscosity of the ambient mantle (S < 1) or the viscosity of the sheet itself (S > 10). Time-dependent solutions with tracers in configuration (2) demonstrate a partial return flow around the leading edge of a retreating slab and return flow around its sides. The extra `edge drag' exerted by the flow around the sides causes transverse deformation of the slab, and makes the sinking speed of a 3-D slab up to 40% less than that of a 2-D slab. A systematic investigation of the slab's interaction with the bottom boundary as a function of η2/η1 and H/h delineates a rich regime diagram of different subduction modes (trench retreating, slab folding, trench advancing) and reveals a new `advancing-folding' mode in which slab folding is preceded by advancing trench motion. The solutions demonstrate that mode selection is controlled by the dip of the leading edge of the slab at the time when it first encounters the bottom boundary.
Modeling and modification of medical 3D objects. The benefit of using a haptic modeling tool.
Kling-Petersen, T; Rydmark, M
2000-01-01
The Computer Laboratory of the medical faculty in Goteborg (Mednet) has since the end of 1998 been one of a limited numbers of participants in the development of a new modeling tool together with SensAble Technologies Inc [http:¿www.sensable.com/]. The software called SensAble FreeForm was officially released at Siggraph September 1999. Briefly, the software mimics the modeling techniques traditionally used by clay artists. An imported model or a user defined block of "clay" can be modified using different tools such as a ball, square block, scrape etc via the use of a SensAble Technologies PHANToM haptic arm. The model will deform in 3D as a result of touching the "clay" with any selected tool and the amount of deformation is linear to the force applied. By getting instantaneous haptic as well as visual feedback, precise and intuitive changes are easily made. While SensAble FreeForm lacks several of the features normally associated with a 3D modeling program (such as text handling, application of surface and bumpmaps, high-end rendering engines, etc) it's strength lies in the ability to rapidly create non-geometric 3D models. For medical use, very few anatomically correct models are created from scratch. However, FreeForm features tools enable advanced modification of reconstructed or 3D scanned models. One of the main problems with 3D laserscanning of medical specimens is that the technique usually leaves holes or gaps in the dataset corresponding to areas in shadows such as orifices, deep grooves etc. By using FreeForms different tools, these defects are easily corrected and gaps are filled out. Similarly, traditional 3D reconstruction (based on serial sections etc) often shows artifacts as a result of the triangulation and/or tessellation processes. These artifacts usually manifest as unnatural ridges or uneven areas ("the accordion effect"). FreeForm contains a smoothing algorithm that enables the user to select an area to be modified and subsequently apply
NASA Technical Reports Server (NTRS)
Colborn, B. L.; Armstrong, T. W.
1992-01-01
A computer model of the three dimensional geometry and material distributions for the LDEF spacecraft, experiment trays, and, for selected trays, the components of experiments within a tray was developed for use in ionizing radiation assessments. The model is being applied to provide 3-D shielding distributions around radiation dosimeters to aid in data interpretation, particularly in assessing the directional properties of the radiation exposure. Also, the model has been interfaced with radiation transport codes for 3-D dosimetry response predictions and for calculations related to determining the accuracy of trapped proton and cosmic ray environment models. The methodology is described used in developing the 3-D LDEF model and the level of detail incorporated. Currently, the trays modeled in detail are F2, F8, and H12 and H3. Applications of the model which are discussed include the 3-D shielding distributions around various dosimeters, the influence of shielding on dosimetry responses, and comparisons of dose predictions based on the present 3-D model vs those from 1-D geometry model approximations used in initial estimates.
Multi-scale self-organisation of edge plasma turbulent transport in 3D global simulations
NASA Astrophysics Data System (ADS)
Tamain, P.; Ghendrih, Ph; Bufferand, H.; Ciraolo, G.; Colin, C.; Fedorczak, N.; Nace, N.; Schwander, F.; Serre, E.
2015-05-01
The 3D global edge turbulence code TOKAM3X is used to study the properties of edge particle turbulent transport in circular limited plasmas, including both closed and open flux surfaces. Turbulence is driven by an incoming particle flux from the core plasma and no scale separation between the equilibrium and the fluctuations is assumed. Simulations show the existence of a complex self-organization of turbulence transport coupling scales ranging from a few Larmor radii up to the machine scale. Particle transport is largely dominated by small scale turbulence with fluctuations forming quasi field-aligned filaments. Radial particle transport is intermittent and associated with the propagation of coherent structures on long distances via avalanches. Long range correlations are also found in the poloidal and toroidal direction. The statistical properties of fluctuations vary with the radial and poloidal directions, with larger fluctuation levels and intermittency found in the outboard scrape-off layer (SOL). Radial turbulent transport is strongly ballooned, with 90% of the flux at the separatrix flowing through the low-field side. One of the main consequences is the existence of quasi-sonic asymmetric parallel flows driving a net rotation of the plasma. Simulations also show the spontaneous onset of an intermittent E × B rotation characterized by a larger shear at the separatrix. Strong correlation is found between the turbulent particle flux and the E × B flow shear in a phenomenology reminiscent of H-mode physics. The poloidal position of the limiter is a key player in the observed dynamics.
PCB modeling in the Gulf of Lions using a 3D coupled model
NASA Astrophysics Data System (ADS)
Alekseenko, Elena; Thouvenin, Bénédicte; Tixier, Céline; Tronczynski, Jacek; Garreau, Pierre; Verney, Romaric; Carlotti, Francois; Espinasse, Boris; Queguiner, Bernard; Baklouti, Melika
2013-04-01
also enables to identify key parameters and assumptions which control contamination pathways in the Gulf of Lions. Thus, this work is based on coupling such complex biogeochemical model (Eco3M), with a PCBs transport model and a model of hydrodynamics (MARS3D) in order to test a scientific exploration tool for the assessment of PCB dispersion in space and time in the Gulf of Lion and of their transfer to zooplankton via biogeochemical processes. In this work we estimate PCB budgets and fluxes into the Gulf of Lions between the different species of PCB, namely: dissolved total, available dissolved, particulate, biosorbed on plankton, assimilated by zooplankton, which are governed by different processes, such as: adsorption/desorption (equilibrium partitioning), bacteria and plankton mortality, zooplankton excretion, grazing, mineralization, volatilization. References Auger P.A., Diaz F., Ulses C., Estornel C., Neveux J., Joux F., Pujo-Pay M. and Naudin J.J., 2011. Functioning of the planktonic ecosystem on the Gulf of Lions shelf (NW Mediterranean) during spring and its impact on the carbon deposition: a field data and 3-D modeling combined approach. Biogeosciences, 8, 3231-3261. André, G., Garreau, P., Garnier, V. and Fraunié, P., 2005. Modeled variability of the sea surface circulation in the North-western Mediterranean Sea and in the Gulf of Lions. Ocean Dynamics, 55, 294-308. Andre, G., Garreau, P., Fraune, P.,2009. Mesoscale slope current variability in the Gulf of Lions. Interpretation of in-situ measurements using a three-dimentional model. Continental Shelf Research, 2, 407-423. Carpenter, D.O., 2006. Polychlorinated biphenyls (PCBs): Routes of exposure and effects on human health. Rev. Environ. Health, 21, 1-23. Dufois F., Garreau P., Le Hir P., Forget P., 2008. Wave- and current-induced bottom shear stress distribution in the Gulf of Lions. Continental Shelf Research, 28(15), 1920-1934. Lohmann, R.;Breivik, K.; Dachs, J.; Muir, D., 2007. Global fate of POPs
Grounding line dynamics inferred from a 3D full-Stokes model solving the contact problem
NASA Astrophysics Data System (ADS)
Favier, Lionel; Gagliardini, Olivier; Durand, Gael; Zwinger, Thomas
2010-05-01
The mass balance of marine ice-sheets, such as the West Antarctic Ice Sheet, is mostly controlled by their grounding line dynamics. Most numerical models simulating marine ice-sheets involve simplifications and do not include all the stress gradients. First results obtained with a 3D full-Stokes model for the grounded ice-sheet / floating ice-shelf transition, using the finite-element code Elmer/Ice, are presented. The initial geometry, which takes into account a dome and a calving front, has been laterally extruded from a previously investigated 2D flowline geometry. The grounding line migration is computed by solving the contact problem between the ice and the rigid downward sloping bedrock, where a non linear friction law is applied in the two horizontal directions. The evolutions of the sea-air and sea-ice interfaces are determined by the solution of a local transport equation. The consistency between the 3D model and the analogous results of the flowline model is shown by comparing the results in the basic extruded case, with no normal flux through lateral boundaries. Thereafter, spatially non uniform perturbations are introduced, to simulate the grounding line dynamics under fully three-dimensional perturbations.
NASA Astrophysics Data System (ADS)
Makra, László; Matyasovszky, István; Guba, Zoltán; Karatzas, Kostas; Anttila, Pia
2011-05-01
The purpose of the study is to identify long-range transport patterns that may have an important influence on PM10 levels in three European cities at different latitudes, namely Thessaloniki, Szeged and Helsinki. A further aim is to separate medium- and long-range PM10 transport for these cities. 4-day, 6-hourly three-dimensional (3D) backward trajectories arriving at these locations at 1200 GMT were computed using the HYSPLIT model over a 5-year period from 2001 to 2005. A k-means clustering algorithm using the Mahalanobis metric was applied in order to develop trajectory types. The 3D delimination of the clusters by the function "convhull" is a novel approach. Two statistical indices were used to evaluate and compare critical daily PM10 exceedances corresponding to the trajectory clusters. For Thessaloniki, the major PM10 transport can be clearly associated with air masses arriving from Central and Southern Europe. Occasional North African dust intrusions over Greece are also found. The transport of particulate matter from North-western Europe to Thessaloniki is of limited importance. For Szeged, Central Europe, Southern Europe and Mid-eastern Europe are the most important sources of PM10. The occasional appearance of North African-origin dust over Hungary is also detected. Local PM10 levels tend to be diluted when air masses arrive at the Carpathian Basin from North-western Europe, the Mid-Atlantic - Western Europe and Northern Europe. For Helsinki, high PM10 concentrations are due to air masses coming from Northern and Eastern Europe including North-western Russia. An occasional Caspian Sea desert influence on particulate levels can also be identified. However, air currents coming from the Northern Atlantics, Northern and North-western Europe tend to dilute PM10 levels. A simple approach is developed in order to separate medium- and long-range PM10 transport for each city.
3D modelling of coupled mass and heat transfer of a convection-oven roasting process.
Feyissa, Aberham Hailu; Gernaey, Krist V; Adler-Nissen, Jens
2013-04-01
A 3D mathematical model of coupled heat and mass transfer describing oven roasting of meat has been developed from first principles. The proposed mechanism for the mass transfer of water is modified and based on a critical literature review of the effect of heat on meat. The model equations are based on a conservation of mass and energy, coupled through Darcy's equations of porous media - the water flow is mainly pressure-driven. The developed model together with theoretical and experimental assessments were used to explain the heat and water transport and the effect of the change in microstructure (permeability, water binding capacity and elastic modulus) that occur during the meat roasting process. The developed coupled partial differential equations were solved by using COMSOL Multiphysics®3.5 and state variables are predicted as functions of both position and time. The proposed mechanism was partially validated by experiments in a convection oven where temperatures were measured online. PMID:23305831
A 3-D multiband closure for radiation and neutron transfer moment models
Ripoll, J.-F. Wray, A.A.
2008-02-01
We derive a 3D multi-band moment model and its associated closure for radiation and neutron transfer. The new closure is analytical and nonlinear but very simple. Its derivation is based on the maximum entropy closure and assumes a Wien shape for the intensity when used in the Eddington tensor. In the multi-band approach, the opacity is re-arranged (binned) according to the opacity value. The multi-band model propagates identically all photons/neutrons having the same opacity. This has been found to be a good approximation on average since the transport is mostly determined by the opacities and less by the frequencies. This same concept is used to derive the closure. We prove on two complex test atmospheres (the solar atmosphere and an artificial atmosphere) that the closure we have derived has good accuracy. All approximations made in deriving the model have been carefully numerically checked and quantified.
Evaluation of Model Recognition for Grammar-Based Automatic 3d Building Model Reconstruction
NASA Astrophysics Data System (ADS)
Yu, Qian; Helmholz, Petra; Belton, David
2016-06-01
In recent years, 3D city models are in high demand by many public and private organisations, and the steadily growing capacity in both quality and quantity are increasing demand. The quality evaluation of these 3D models is a relevant issue both from the scientific and practical points of view. In this paper, we present a method for the quality evaluation of 3D building models which are reconstructed automatically from terrestrial laser scanning (TLS) data based on an attributed building grammar. The entire evaluation process has been performed in all the three dimensions in terms of completeness and correctness of the reconstruction. Six quality measures are introduced to apply on four datasets of reconstructed building models in order to describe the quality of the automatic reconstruction, and also are assessed on their validity from the evaluation point of view.
NASA Astrophysics Data System (ADS)
Koehl, M.; Brigand, N.
2012-08-01
The site of the Engelbourg ruined castle in Thann, Alsace, France, has been for some years the object of all the attention of the city, which is the owner, and also of partners like historians and archaeologists who are in charge of its study. The valuation of the site is one of the main objective, as well as its conservation and its knowledge. The aim of this project is to use the environment of the virtual tour viewer as new base for an Archaeological Knowledge and Information System (AKIS). With available development tools we add functionalities in particular through diverse scripts that convert the viewer into a real 3D interface. By beginning with a first virtual tour that contains about fifteen panoramic images, the site of about 150 times 150 meters can be completely documented by offering the user a real interactivity and that makes visualization very concrete, almost lively. After the choice of pertinent points of view, panoramic images were realized. For the documentation, other sets of images were acquired at various seasons and climate conditions, which allow documenting the site in different environments and states of vegetation. The final virtual tour was deducted from them. The initial 3D model of the castle, which is virtual too, was also joined in the form of panoramic images for completing the understanding of the site. A variety of types of hotspots were used to connect the whole digital documentation to the site, including videos (as reports during the acquisition phases, during the restoration works, during the excavations, etc.), digital georeferenced documents (archaeological reports on the various constituent elements of the castle, interpretation of the excavations and the searches, description of the sets of collected objects, etc.). The completely personalized interface of the system allows either to switch from a panoramic image to another one, which is the classic case of the virtual tours, or to go from a panoramic photographic image
Towards Precise Metadata-set for Discovering 3D Geospatial Models in Geo-portals
NASA Astrophysics Data System (ADS)
Zamyadi, A.; Pouliot, J.; Bédard, Y.
2013-09-01
Accessing 3D geospatial models, eventually at no cost and for unrestricted use, is certainly an important issue as they become popular among participatory communities, consultants, and officials. Various geo-portals, mainly established for 2D resources, have tried to provide access to existing 3D resources such as digital elevation model, LIDAR or classic topographic data. Describing the content of data, metadata is a key component of data discovery in geo-portals. An inventory of seven online geo-portals and commercial catalogues shows that the metadata referring to 3D information is very different from one geo-portal to another as well as for similar 3D resources in the same geo-portal. The inventory considered 971 data resources affiliated with elevation. 51% of them were from three geo-portals running at Canadian federal and municipal levels whose metadata resources did not consider 3D model by any definition. Regarding the remaining 49% which refer to 3D models, different definition of terms and metadata were found, resulting in confusion and misinterpretation. The overall assessment of these geo-portals clearly shows that the provided metadata do not integrate specific and common information about 3D geospatial models. Accordingly, the main objective of this research is to improve 3D geospatial model discovery in geo-portals by adding a specific metadata-set. Based on the knowledge and current practices on 3D modeling, and 3D data acquisition and management, a set of metadata is proposed to increase its suitability for 3D geospatial models. This metadata-set enables the definition of genuine classes, fields, and code-lists for a 3D metadata profile. The main structure of the proposal contains 21 metadata classes. These classes are classified in three packages as General and Complementary on contextual and structural information, and Availability on the transition from storage to delivery format. The proposed metadata set is compared with Canadian Geospatial
Why 3D? The Need for Solution Based Modeling in a National Geoscience Organization.
NASA Astrophysics Data System (ADS)
Terrington, Ricky; Napier, Bruce; Howard, Andy; Ford, Jon; Hatton, William
2008-05-01
In recent years national geoscience organizations have increasingly utilized 3D model data as an output to the stakeholder community. Advances in both software and hardware have led to an increasing use of 3D depictions of geoscience data alongside the standard 2D data