Science.gov

Sample records for 3d global hybrid

  1. Effects of Kinetic Processes in Shaping Io's Global Plasma Environment: A 3D Hybrid Model

    NASA Technical Reports Server (NTRS)

    Lipatov, Alexander S.; Combi, Michael R.

    2006-01-01

    The global dynamics of the ionized and neutral gases in the environment of Io plays an important role in the interaction of Jupiter s corotating magnetospheric plasma with Io. Stationary simulations of this problem have already been done using the magnetohydrodynamics (MHD) and the electrodynamics approaches. One of the major results of recent simplified two-fluid model simulations [Saur, J., Neubauer, F.M., Strobel, D.F., Summers, M.E., 2002. J. Geophys. Res. 107 (SMP5), 1-18] was the production of the structure of the double-peak in the magnetic field signature of the Io flyby. These could not be explained before by standard MHD models. In this paper, we present a hybrid simulation for Io with kinetic ions and fluid electrons. This method employs a fluid description for electrons and neutrals, whereas for ions a particle approach is used. We also take into account charge-exchange and photoionization processes and solve self-consistently for electric and magnetic fields. Our model may provide a much more accurate description for the ion dynamics than previous approaches and allows us to account for the realistic anisotropic ion velocity distribution that cannot be done in fluid simulations with isotropic temperatures. The first results of such a simulation of the dynamics of ions in Io s environment are discussed in this paper. Comparison with the Galileo IO flyby results shows that this approach provides an accurate physical basis for the interaction and can therefore naturally reproduce all the observed salient features.

  2. Effects of Kinetic Processes in Shaping Io's Global Plasma Environment: A 3D Hybrid Model

    NASA Technical Reports Server (NTRS)

    Lipatov, Alexander S.; Combi, Michael R.

    2004-01-01

    The global dynamics of the ionized and neutral components in the environment of Io plays an important role in the interaction of Jupiter's corotating magnetospheric plasma with Io. The stationary simulation of this problem was done in the MHD and the electrodynamics approaches. One of the main significant results from the simplified two-fluid model simulations was a production of the structure of the double-peak in the magnetic field signature of the I0 flyby that could not be explained by standard MHD models. In this paper, we develop a method of kinetic ion simulation. This method employs the fluid description for electrons and neutrals whereas for ions multilevel, drift-kinetic and particle, approaches are used. We also take into account charge-exchange and photoionization processes. Our model provides much more accurate description for ion dynamics and allows us to take into account the realistic anisotropic ion distribution that cannot be done in fluid simulations. The first results of such simulation of the dynamics of ions in the Io's environment are discussed in this paper.

  3. A hybrid framework of multiple active appearance models and global registration for 3D prostate segmentation in MRI

    NASA Astrophysics Data System (ADS)

    Ghose, Soumya; Oliver, Arnau; Martí, Robert; Lladó, Xavier; Freixenet, Jordi; Mitra, Jhimli; Vilanova, Joan C.; Meriaudeau, Fabrice

    2012-02-01

    Real-time fusion of Magnetic Resonance (MR) and Trans Rectal Ultra Sound (TRUS) images aid in the localization of malignant tissues in TRUS guided prostate biopsy. Registration performed on segmented contours of the prostate reduces computational complexity and improves the multimodal registration accuracy. However, accurate and computationally efficient 3D segmentation of the prostate in MR images could be a challenging task due to inter-patient shape and intensity variability of the prostate gland. In this work, we propose to use multiple statistical shape and appearance models to segment the prostate in 2D and a global registration framework to impose shape restriction in 3D. Multiple mean parametric models of the shape and appearance corresponding to the apex, central and base regions of the prostate gland are derived from principal component analysis (PCA) of prior shape and intensity information of the prostate from the training data. The estimated parameters are then modified with the prior knowledge of the optimization space to achieve segmentation in 2D. The 2D segmented slices are then rigidly registered with the average 3D model produced by affine registration of the ground truth of the training datasets to minimize pose variations and impose 3D shape restriction. The proposed method achieves a mean Dice similarity coefficient (DSC) value of 0.88+/-0.11, and mean Hausdorff distance (HD) of 3.38+/-2.81 mm when validated with 15 prostate volumes of a public dataset in leave-one-out validation framework. The results achieved are better compared to some of the works in the literature.

  4. Global effects of transmitted shock wave propagation through the Earth's inner magnetosphere: First results from 3-D hybrid kinetic modeling

    NASA Astrophysics Data System (ADS)

    Lipatov, A. S.; Sibeck, D. G.

    2016-09-01

    We use a new hybrid kinetic model to simulate the response of ring current, outer radiation belt, and plasmaspheric particle populations to impulsive interplanetary shocks. Since particle distributions attending the interplanetary shock waves and in the ring current and radiation belts are non-Maxwellian, wave-particle interactions play a crucial role in energy transport within the inner magnetosphere. Finite gyroradius effects become important in mass loading the shock waves with the background plasma in the presence of higher energy ring current and radiation belt ions and electrons. Initial results show that shocks cause strong deformations in the global structure of the ring current, radiation belt, and plasmasphere. The ion velocity distribution functions at the shock front, in the ring current, and in the radiation belt help us determine energy transport through the Earth's inner magnetosphere.

  5. Hybrid segmentation framework for 3D medical image analysis

    NASA Astrophysics Data System (ADS)

    Chen, Ting; Metaxas, Dimitri N.

    2003-05-01

    Medical image segmentation is the process that defines the region of interest in the image volume. Classical segmentation methods such as region-based methods and boundary-based methods cannot make full use of the information provided by the image. In this paper we proposed a general hybrid framework for 3D medical image segmentation purposes. In our approach we combine the Gibbs Prior model, and the deformable model. First, Gibbs Prior models are applied onto each slice in a 3D medical image volume and the segmentation results are combined to a 3D binary masks of the object. Then we create a deformable mesh based on this 3D binary mask. The deformable model will be lead to the edge features in the volume with the help of image derived external forces. The deformable model segmentation result can be used to update the parameters for Gibbs Prior models. These methods will then work recursively to reach a global segmentation solution. The hybrid segmentation framework has been applied to images with the objective of lung, heart, colon, jaw, tumor, and brain. The experimental data includes MRI (T1, T2, PD), CT, X-ray, Ultra-Sound images. High quality results are achieved with relatively efficient time cost. We also did validation work using expert manual segmentation as the ground truth. The result shows that the hybrid segmentation may have further clinical use.

  6. 3D Visualization of Global Ocean Circulation

    NASA Astrophysics Data System (ADS)

    Nelson, V. G.; Sharma, R.; Zhang, E.; Schmittner, A.; Jenny, B.

    2015-12-01

    Advanced 3D visualization techniques are seldom used to explore the dynamic behavior of ocean circulation. Streamlines are an effective method for visualization of flow, and they can be designed to clearly show the dynamic behavior of a fluidic system. We employ vector field editing and extraction software to examine the topology of velocity vector fields generated by a 3D global circulation model coupled to a one-layer atmosphere model simulating preindustrial and last glacial maximum (LGM) conditions. This results in a streamline-based visualization along multiple density isosurfaces on which we visualize points of vertical exchange and the distribution of properties such as temperature and biogeochemical tracers. Previous work involving this model examined the change in the energetics driving overturning circulation and mixing between simulations of LGM and preindustrial conditions. This visualization elucidates the relationship between locations of vertical exchange and mixing, as well as demonstrates the effects of circulation and mixing on the distribution of tracers such as carbon isotopes.

  7. Improved hybrid optimization algorithm for 3D protein structure prediction.

    PubMed

    Zhou, Changjun; Hou, Caixia; Wei, Xiaopeng; Zhang, Qiang

    2014-07-01

    A new improved hybrid optimization algorithm - PGATS algorithm, which is based on toy off-lattice model, is presented for dealing with three-dimensional protein structure prediction problems. The algorithm combines the particle swarm optimization (PSO), genetic algorithm (GA), and tabu search (TS) algorithms. Otherwise, we also take some different improved strategies. The factor of stochastic disturbance is joined in the particle swarm optimization to improve the search ability; the operations of crossover and mutation that are in the genetic algorithm are changed to a kind of random liner method; at last tabu search algorithm is improved by appending a mutation operator. Through the combination of a variety of strategies and algorithms, the protein structure prediction (PSP) in a 3D off-lattice model is achieved. The PSP problem is an NP-hard problem, but the problem can be attributed to a global optimization problem of multi-extremum and multi-parameters. This is the theoretical principle of the hybrid optimization algorithm that is proposed in this paper. The algorithm combines local search and global search, which overcomes the shortcoming of a single algorithm, giving full play to the advantage of each algorithm. In the current universal standard sequences, Fibonacci sequences and real protein sequences are certified. Experiments show that the proposed new method outperforms single algorithms on the accuracy of calculating the protein sequence energy value, which is proved to be an effective way to predict the structure of proteins. PMID:25069136

  8. Analytical finite element matrix elements and global matrix assembly for hierarchical 3-D vector basis functions within the hybrid finite element boundary integral method

    NASA Astrophysics Data System (ADS)

    Li, L.; Wang, K.; Li, H.; Eibert, T. F.

    2014-11-01

    A hybrid higher-order finite element boundary integral (FE-BI) technique is discussed where the higher-order FE matrix elements are computed by a fully analytical procedure and where the gobal matrix assembly is organized by a self-identifying procedure of the local to global transformation. This assembly procedure applys to both, the FE part as well as the BI part of the algorithm. The geometry is meshed into three-dimensional tetrahedra as finite elements and nearly orthogonal hierarchical basis functions are employed. The boundary conditions are implemented in a strong sense such that the boundary values of the volume basis functions are directly utilized within the BI, either for the tangential electric and magnetic fields or for the asssociated equivalent surface current densities by applying a cross product with the unit surface normals. The self-identified method for the global matrix assembly automatically discerns the global order of the basis functions for generating the matrix elements. Higher order basis functions do need more unknowns for each single FE, however, fewer FEs are needed to achieve the same satisfiable accuracy. This improvement provides a lot more flexibility for meshing and allows the mesh size to raise up to λ/3. The performance of the implemented system is evaluated in terms of computation time, accuracy and memory occupation, where excellent results with respect to precision and computation times of large scale simulations are found.

  9. R3D Align: global pairwise alignment of RNA 3D structures using local superpositions

    PubMed Central

    Rahrig, Ryan R.; Leontis, Neocles B.; Zirbel, Craig L.

    2010-01-01

    Motivation: Comparing 3D structures of homologous RNA molecules yields information about sequence and structural variability. To compare large RNA 3D structures, accurate automatic comparison tools are needed. In this article, we introduce a new algorithm and web server to align large homologous RNA structures nucleotide by nucleotide using local superpositions that accommodate the flexibility of RNA molecules. Local alignments are merged to form a global alignment by employing a maximum clique algorithm on a specially defined graph that we call the ‘local alignment’ graph. Results: The algorithm is implemented in a program suite and web server called ‘R3D Align’. The R3D Align alignment of homologous 3D structures of 5S, 16S and 23S rRNA was compared to a high-quality hand alignment. A full comparison of the 16S alignment with the other state-of-the-art methods is also provided. The R3D Align program suite includes new diagnostic tools for the structural evaluation of RNA alignments. The R3D Align alignments were compared to those produced by other programs and were found to be the most accurate, in comparison with a high quality hand-crafted alignment and in conjunction with a series of other diagnostics presented. The number of aligned base pairs as well as measures of geometric similarity are used to evaluate the accuracy of the alignments. Availability: R3D Align is freely available through a web server http://rna.bgsu.edu/R3DAlign. The MATLAB source code of the program suite is also freely available for download at that location. Supplementary information: Supplementary data are available at Bioinformatics online. Contact: r-rahrig@onu.edu PMID:20929913

  10. Hybrid additive manufacturing of 3D electronic systems

    NASA Astrophysics Data System (ADS)

    Li, J.; Wasley, T.; Nguyen, T. T.; Ta, V. D.; Shephard, J. D.; Stringer, J.; Smith, P.; Esenturk, E.; Connaughton, C.; Kay, R.

    2016-10-01

    A novel hybrid additive manufacturing (AM) technology combining digital light projection (DLP) stereolithography (SL) with 3D micro-dispensing alongside conventional surface mount packaging is presented in this work. This technology overcomes the inherent limitations of individual AM processes and integrates seamlessly with conventional packaging processes to enable the deposition of multiple materials. This facilitates the creation of bespoke end-use products with complex 3D geometry and multi-layer embedded electronic systems. Through a combination of four-point probe measurement and non-contact focus variation microscopy, it was identified that there was no obvious adverse effect of DLP SL embedding process on the electrical conductivity of printed conductors. The resistivity maintained to be less than 4  ×  10-4 Ω · cm before and after DLP SL embedding when cured at 100 °C for 1 h. The mechanical strength of SL specimens with thick polymerized layers was also identified through tensile testing. It was found that the polymerization thickness should be minimised (less than 2 mm) to maximise the bonding strength. As a demonstrator a polymer pyramid with embedded triple-layer 555 LED blinking circuitry was successfully fabricated to prove the technical viability.

  11. Enhanced hybrid search algorithm for protein structure prediction using the 3D-HP lattice model.

    PubMed

    Zhou, Changjun; Hou, Caixia; Zhang, Qiang; Wei, Xiaopeng

    2013-09-01

    The problem of protein structure prediction in the hydrophobic-polar (HP) lattice model is the prediction of protein tertiary structure. This problem is usually referred to as the protein folding problem. This paper presents a method for the application of an enhanced hybrid search algorithm to the problem of protein folding prediction, using the three dimensional (3D) HP lattice model. The enhanced hybrid search algorithm is a combination of the particle swarm optimizer (PSO) and tabu search (TS) algorithms. Since the PSO algorithm entraps local minimum in later evolution extremely easily, we combined PSO with the TS algorithm, which has properties of global optimization. Since the technologies of crossover and mutation are applied many times to PSO and TS algorithms, so enhanced hybrid search algorithm is called the MCMPSO-TS (multiple crossover and mutation PSO-TS) algorithm. Experimental results show that the MCMPSO-TS algorithm can find the best solutions so far for the listed benchmarks, which will help comparison with any future paper approach. Moreover, real protein sequences and Fibonacci sequences are verified in the 3D HP lattice model for the first time. Compared with the previous evolutionary algorithms, the new hybrid search algorithm is novel, and can be used effectively to predict 3D protein folding structure. With continuous development and changes in amino acids sequences, the new algorithm will also make a contribution to the study of new protein sequences. PMID:23824509

  12. GBS: Global 3D simulation of tokamak edge region

    NASA Astrophysics Data System (ADS)

    Zhu, Ben; Fisher, Dustin; Rogers, Barrett; Ricci, Paolo

    2012-10-01

    A 3D two-fluid global code, namely Global Braginskii Solver (GBS), is being developed to explore the physics of turbulent transport, confinement, self-consistent profile formation, pedestal scaling and related phenomena in the edge region of tokamaks. Aimed at solving drift-reduced Braginskii equations [1] in complex magnetic geometry, the GBS is used for turbulence simulation in SOL region. In the recent upgrade, the simulation domain is expanded into close flux region with twist-shift boundary conditions. Hence, the new GBS code is able to explore global transport physics in an annular full-torus domain from the top of the pedestal into the far SOL. We are in the process of identifying and analyzing the linear and nonlinear instabilities in the system using the new GBS code. Preliminary results will be presented and compared with other codes if possible.[4pt] [1] A. Zeiler, J. F. Drake and B. Rogers, Phys. Plasmas 4, 2134 (1997)

  13. Improving Semantic Updating Method on 3d City Models Using Hybrid Semantic-Geometric 3d Segmentation Technique

    NASA Astrophysics Data System (ADS)

    Sharkawi, K.-H.; Abdul-Rahman, A.

    2013-09-01

    to LoD4. The accuracy and structural complexity of the 3D objects increases with the LoD level where LoD0 is the simplest LoD (2.5D; Digital Terrain Model (DTM) + building or roof print) while LoD4 is the most complex LoD (architectural details with interior structures). Semantic information is one of the main components in CityGML and 3D City Models, and provides important information for any analyses. However, more often than not, the semantic information is not available for the 3D city model due to the unstandardized modelling process. One of the examples is where a building is normally generated as one object (without specific feature layers such as Roof, Ground floor, Level 1, Level 2, Block A, Block B, etc). This research attempts to develop a method to improve the semantic data updating process by segmenting the 3D building into simpler parts which will make it easier for the users to select and update the semantic information. The methodology is implemented for 3D buildings in LoD2 where the buildings are generated without architectural details but with distinct roof structures. This paper also introduces hybrid semantic-geometric 3D segmentation method that deals with hierarchical segmentation of a 3D building based on its semantic value and surface characteristics, fitted by one of the predefined primitives. For future work, the segmentation method will be implemented as part of the change detection module that can detect any changes on the 3D buildings, store and retrieve semantic information of the changed structure, automatically updates the 3D models and visualize the results in a userfriendly graphical user interface (GUI).

  14. Mars Odyssey Seen by Mars Global Surveyor (3-D)

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This stereoscopic picture of NASA's Mars Odyssey spacecraft was created from two views of that spacecraft taken by the Mars Orbiter Camera on NASA's Mars Global Surveyor. The camera's successful imaging of Odyssey and of the European Space Agency's Mars Express in April 2005 produced the first pictures of any spacecraft orbiting Mars taken by another spacecraft orbiting Mars.

    Mars Global Surveyor acquired this image of Mars Odyssey on April 21, 2005. The stereoscopic picture combines one view captured while the two orbiters were 90 kilometers (56 miles) apart with a second view captured from a slightly different angle when the two orbiters were 135 kilometers (84 miles) apart. For proper viewing, the user needs '3-D' glasses with red over the left eye and blue over the right eye.

    The Mars Orbiter Camera can resolve features on the surface of Mars as small as a few meters or yards across from Mars Global Surveyor's orbital altitude of 350 to 405 kilometers (217 to 252 miles). From a distance of 100 kilometers (62 miles), the camera would be able to resolve features substantially smaller than 1 meter or yard across.

    Mars Odyssey was launched on April 7, 2001, and reached Mars on Oct. 24, 2001. Mars Global Surveyor left Earth on Nov. 7, 1996, and arrived in Mars orbit on Sept. 12, 1997. Both orbiters are in an extended mission phase, both have relayed data from the Mars Exploration Rovers, and both are continuing to return exciting new results from Mars. JPL, a division of the California Institute of Technology, Pasadena, manages both missions for NASA's Science Mission Directorate, Washington, D.C.

  15. Hybrid 3D printing: a game-changer in personalized cardiac medicine?

    PubMed

    Kurup, Harikrishnan K N; Samuel, Bennett P; Vettukattil, Joseph J

    2015-12-01

    Three-dimensional (3D) printing in congenital heart disease has the potential to increase procedural efficiency and patient safety by improving interventional and surgical planning and reducing radiation exposure. Cardiac magnetic resonance imaging and computed tomography are usually the source datasets to derive 3D printing. More recently, 3D echocardiography has been demonstrated to derive 3D-printed models. The integration of multiple imaging modalities for hybrid 3D printing has also been shown to create accurate printed heart models, which may prove to be beneficial for interventional cardiologists, cardiothoracic surgeons, and as an educational tool. Further advancements in the integration of different imaging modalities into a single platform for hybrid 3D printing and virtual 3D models will drive the future of personalized cardiac medicine.

  16. Hybrid 3D printing: a game-changer in personalized cardiac medicine?

    PubMed

    Kurup, Harikrishnan K N; Samuel, Bennett P; Vettukattil, Joseph J

    2015-12-01

    Three-dimensional (3D) printing in congenital heart disease has the potential to increase procedural efficiency and patient safety by improving interventional and surgical planning and reducing radiation exposure. Cardiac magnetic resonance imaging and computed tomography are usually the source datasets to derive 3D printing. More recently, 3D echocardiography has been demonstrated to derive 3D-printed models. The integration of multiple imaging modalities for hybrid 3D printing has also been shown to create accurate printed heart models, which may prove to be beneficial for interventional cardiologists, cardiothoracic surgeons, and as an educational tool. Further advancements in the integration of different imaging modalities into a single platform for hybrid 3D printing and virtual 3D models will drive the future of personalized cardiac medicine. PMID:26465262

  17. Efficient global wave propagation adapted to 3-D structural complexity: a pseudo-spectral/spectral-element approach

    NASA Astrophysics Data System (ADS)

    Leng, Kuangdai; Nissen-Meyer, Tarje; van Driel, Martin

    2016-09-01

    We present a new, computationally efficient numerical method to simulate global seismic wave propagation in realistic 3-D Earth models. We characterize the azimuthal dependence of 3-D wavefields in terms of Fourier series, such that the 3-D equations of motion reduce to an algebraic system of coupled 2-D meridian equations, which is then solved by a 2-D spectral element method (SEM). Computational efficiency of such a hybrid method stems from lateral smoothness of 3-D Earth models and axial singularity of seismic point sources, which jointly confine the Fourier modes of wavefields to a few lower orders. We show novel benchmarks for global wave solutions in 3-D structures between our method and an independent, fully discretized 3-D SEM with remarkable agreement. Performance comparisons are carried out on three state-of-the-art tomography models, with seismic period ranging from 34s down to 11s. It turns out that our method has run up to two orders of magnitude faster than the 3-D SEM, featured by a computational advantage expanding with seismic frequency.

  18. Mobile 3D quality of experience evaluation: a hybrid data collection and analysis approach

    NASA Astrophysics Data System (ADS)

    Utriainen, Timo; Häyrynen, Jyrki; Jumisko-Pyykkö, Satu; Boev, Atanas; Gotchev, Atanas; Hannuksela, Miska M.

    2011-02-01

    The paper presents a hybrid approach to study the user's experienced quality of 3D visual content on mobile autostereoscopic displays. It combines extensive subjective tests with collection and objective analysis of eye-tracked data. 3D cues which are significant for mobiles are simulated in the generated 3D test content. The methodology for conducting subjective quality evaluation includes hybrid data-collection of quantitative quality preferences, qualitative impressions, and binocular eye-tracking. We present early results of the subjective tests along with eye movement reaction times, areas of interest and heatmaps obtained from raw eye-tracked data after statistical analysis. The study contributes to the question what is important to be visualized on portable auto-stereoscopic displays and how to maintain and visually enhance the quality of 3D content for such displays.

  19. A hybrid method for the computation of quasi-3D seismograms.

    NASA Astrophysics Data System (ADS)

    Masson, Yder; Romanowicz, Barbara

    2013-04-01

    The development of powerful computer clusters and efficient numerical computation methods, such as the Spectral Element Method (SEM) made possible the computation of seismic wave propagation in a heterogeneous 3D earth. However, the cost of theses computations is still problematic for global scale tomography that requires hundreds of such simulations. Part of the ongoing research effort is dedicated to the development of faster modeling methods based on the spectral element method. Capdeville et al. (2002) proposed to couple SEM simulations with normal modes calculation (C-SEM). Nissen-Meyer et al. (2007) used 2D SEM simulations to compute 3D seismograms in a 1D earth model. Thanks to these developments, and for the first time, Lekic et al. (2011) developed a 3D global model of the upper mantle using SEM simulations. At the local and continental scale, adjoint tomography that is using a lot of SEM simulation can be implemented on current computers (Tape, Liu et al. 2009). Due to their smaller size, these models offer higher resolution. They provide us with images of the crust and the upper part of the mantle. In an attempt to teleport such local adjoint tomographic inversions into the deep earth, we are developing a hybrid method where SEM computation are limited to a region of interest within the earth. That region can have an arbitrary shape and size. Outside this region, the seismic wavefield is extrapolated to obtain synthetic data at the Earth's surface. A key feature of the method is the use of a time reversal mirror to inject the wavefield induced by distant seismic source into the region of interest (Robertsson and Chapman 2000). We compute synthetic seismograms as follow: Inside the region of interest, we are using regional spectral element software RegSEM to compute wave propagation in 3D. Outside this region, the wavefield is extrapolated to the surface by convolution with the Green's functions from the mirror to the seismic stations. For now, these

  20. Applications of three-dimensional (3D) printing for microswimmers and bio-hybrid robotics.

    PubMed

    Stanton, M M; Trichet-Paredes, C; Sánchez, S

    2015-04-01

    This article will focus on recent reports that have applied three-dimensional (3D) printing for designing millimeter to micrometer architecture for robotic motility. The utilization of 3D printing has rapidly grown in applications for medical prosthetics and scaffolds for organs and tissue, but more recently has been implemented for designing mobile robotics. With an increase in the demand for devices to perform in fragile and confined biological environments, it is crucial to develop new miniaturized, biocompatible 3D systems. Fabrication of materials at different scales with different properties makes 3D printing an ideal system for creating frameworks for small-scale robotics. 3D printing has been applied for the design of externally powered, artificial microswimmers and studying their locomotive capabilities in different fluids. Printed materials have also been incorporated with motile cells for bio-hybrid robots capable of functioning by cell contraction and swimming. These 3D devices offer new methods of robotic motility for biomedical applications requiring miniature structures. Traditional 3D printing methods, where a structure is fabricated in an additive process from a digital design, and non-traditional 3D printing methods, such as lithography and molding, will be discussed.

  1. Applications of three-dimensional (3D) printing for microswimmers and bio-hybrid robotics.

    PubMed

    Stanton, M M; Trichet-Paredes, C; Sánchez, S

    2015-04-01

    This article will focus on recent reports that have applied three-dimensional (3D) printing for designing millimeter to micrometer architecture for robotic motility. The utilization of 3D printing has rapidly grown in applications for medical prosthetics and scaffolds for organs and tissue, but more recently has been implemented for designing mobile robotics. With an increase in the demand for devices to perform in fragile and confined biological environments, it is crucial to develop new miniaturized, biocompatible 3D systems. Fabrication of materials at different scales with different properties makes 3D printing an ideal system for creating frameworks for small-scale robotics. 3D printing has been applied for the design of externally powered, artificial microswimmers and studying their locomotive capabilities in different fluids. Printed materials have also been incorporated with motile cells for bio-hybrid robots capable of functioning by cell contraction and swimming. These 3D devices offer new methods of robotic motility for biomedical applications requiring miniature structures. Traditional 3D printing methods, where a structure is fabricated in an additive process from a digital design, and non-traditional 3D printing methods, such as lithography and molding, will be discussed. PMID:25632887

  2. 3D graphene-based hybrid materials: synthesis and applications in energy storage and conversion.

    PubMed

    Shi, Qiurong; Cha, Younghwan; Song, Yang; Lee, Jung-In; Zhu, Chengzhou; Li, Xiaoyu; Song, Min-Kyu; Du, Dan; Lin, Yuehe

    2016-08-25

    Porous 3D graphene-based hybrid materials (3D GBHMs) are currently attractive nanomaterials employed in the field of energy. Heteroatom-doped 3D graphene and metal, metal oxide, and polymer-decorated 3D graphene with modified electronic and atomic structures provide promising performance as electrode materials in energy storage and conversion. Numerous synthesis methods such as self-assembly, templating, electrochemical deposition, and supercritical CO2, pave the way to mass production of 3D GBHMs in the commercialization of energy devices. This review summarizes recent advances in the fabrication of 3D GBHMs with well-defined architectures such as finely controlled pore sizes, heteroatom doping types and levels. Moreover, current progress toward applications in fuel cells, supercapacitors and batteries employing 3D GBHMs is also highlighted, along with the detailed mechanisms of the enhanced electrochemical performance. Furthermore, current critical issues, challenges and future prospects with respect to applications of 3D GBHMs in practical devices are discussed at the end of this review. PMID:27531643

  3. Improved time-space method for 3-D heat transfer problems including global warming

    SciTech Connect

    Saitoh, T.S.; Wakashima, Shinichiro

    1999-07-01

    In this paper, the Time-Space Method (TSM) which has been proposed for solving general heat transfer and fluid flow problems was improved in order to cover global and urban warming. The TSM is effective in almost all-transient heat transfer and fluid flow problems, and has been already applied to the 2-D melting problems (or moving boundary problems). The computer running time will be reduced to only 1/100th--1/1000th of the existing schemes for 2-D and 3-D problems. However, in order to apply to much larger-scale problems, for example, global warming, urban warming and general ocean circulation, the SOR method (or other iterative methods) in four dimensions is somewhat tedious and provokingly slow. Motivated by the above situation, the authors improved the speed of iteration of the previous TSM by introducing the following ideas: (1) Timewise chopping: Time domain is chopped into small peaches to save memory requirement; (2) Adaptive iteration: Converged region is eliminated for further iteration; (3) Internal selective iteration: Equation with slow iteration speed in iterative procedure is selectively iterated to accelerate entire convergence; and (4) False transient integration: False transient term is added to the Poisson-type equation and the relevant solution is regarded as a parabolic equation. By adopting the above improvements, the higher-order finite different schemes and the hybrid mesh, the computer running time for the TSM is reduced to some 1/4600th of the conventional explicit method for a typical 3-D natural convection problem in a closed cavity. The proposed TSM will be more efficacious for large-scale environmental problems, such as global warming, urban warming and general ocean circulation, in which a tremendous computing time would be required.

  4. Global stability analysis of turbulent 3D wakes

    NASA Astrophysics Data System (ADS)

    Rigas, Georgios; Sipp, Denis; Juniper, Matthew

    2015-11-01

    At low Reynolds numbers, corresponding to laminar and transitional regimes, hydrodynamic stability theory has aided the understanding of the dynamics of bluff body wake-flows and the application of effective control strategies. However, flows of fundamental importance to many industries, in particular the transport industry, involve high Reynolds numbers and turbulent wakes. Despite their turbulence, such wake flows exhibit organisation which is manifested as coherent structures. Recent work has shown that the turbulent coherent structures retain the shape of the symmetry-breaking laminar instabilities and only those manifest as large-scale structures in the near wake (Rigas et al., JFM vol. 750:R5 2014, JFM vol. 778:R2 2015). Based on the findings of the persistence of the laminar instabilities at high Reynolds numbers, we investigate the global stability characteristics of a turbulent wake generated behind a bluff three-dimensional axisymmetric body. We perform a linear global stability analysis on the experimentally obtained mean flow and we recover the dynamic characteristics and spatial structure of the coherent structures, which are linked to the transitional instabilities. A detailed comparison of the predictions with the experimental measurements will be provided.

  5. Hybridization and hybrid speciation under global change.

    PubMed

    Vallejo-Marín, Mario; Hiscock, Simon J

    2016-09-01

    Contents 1170 I. 1170 II. 1172 III. 1175 IV. 1180 V. 1183 1184 References 1184 SUMMARY: An unintended consequence of global change is an increase in opportunities for hybridization among previously isolated lineages. Here we illustrate how global change can facilitate the breakdown of reproductive barriers and the formation of hybrids, drawing on the flora of the British Isles for insight. Although global change may ameliorate some of the barriers preventing hybrid establishment, for example by providing new ecological niches for hybrids, it will have limited effects on environment-independent post-zygotic barriers. For example, genic incompatibilities and differences in chromosome numbers and structure within hybrid genomes are unlikely to be affected by global change. We thus speculate that global change will have a larger effect on eroding pre-zygotic barriers (eco-geographical isolation and phenology) than post-zygotic barriers, shifting the relative importance of these two classes of reproductive barriers from what is usually seen in naturally produced hybrids where pre-zygotic barriers are the largest contributors to reproductive isolation. Although the long-term fate of neo-hybrids is still to be determined, the massive impact of global change on the dynamics and distribution of biodiversity generates an unprecedented opportunity to study large numbers of unpredicted, and often replicated, hybridization 'experiments', allowing us to peer into the birth and death of evolutionary lineages. PMID:27214560

  6. Hybrid helical magnetic microrobots obtained by 3D template-assisted electrodeposition.

    PubMed

    Zeeshan, Muhammad A; Grisch, Roman; Pellicer, Eva; Sivaraman, Kartik M; Peyer, Kathrin E; Sort, Jordi; Özkale, Berna; Sakar, Mahmut S; Nelson, Bradley J; Pané, Salvador

    2014-04-01

    Hybrid helical magnetic microrobots are achieved by sequential electrodeposition of a CoNi alloy and PPy inside a photoresist template patterned by 3D laser lithography. A controlled actuation of the microrobots by a rotating magnetic field is demonstrated in a fluidic environment.

  7. A hybrid approach for addressing ring flexibility in 3D database searching.

    PubMed

    Sadowski, J

    1997-01-01

    A hybrid approach for flexible 3D database searching is presented that addresses the problem of ring flexibility. It combines the explicit storage of up to 25 multiple conformations of rings, with up to eight atoms, generated by the 3D structure generator CORINA with the power of a torsional fitting technique implemented in the 3D database system UNITY. A comparison with the original UNITY approach, using a database with about 130,000 entries and five different pharmacophore queries, was performed. The hybrid approach scored, on an average, 10-20% more hits than the reference run. Moreover, specific problems with unrealistic hit geometries produced by the original approach can be excluded. In addition, the influence of the maximum number of ring conformations per molecule was investigated. An optimal number of 10 conformations per molecule is recommended.

  8. Hybrid atlas-based and image-based approach for segmenting 3D brain MRIs

    NASA Astrophysics Data System (ADS)

    Bueno, Gloria; Musse, Olivier; Heitz, Fabrice; Armspach, Jean-Paul

    2001-07-01

    This work is a contribution to the problem of localizing key cerebral structures in 3D MRIs and its quantitative evaluation. In pursuing it, the cooperation between an image-based segmentation method and a hierarchical deformable registration approach has been considered. The segmentation relies on two main processes: homotopy modification and contour decision. The first one is achieved by a marker extraction stage where homogeneous 3D regions of an image, I(s), from the data set are identified. These regions, M(I), are obtained combining information from deformable atlas, achieved by the warping of eight previous labeled maps on I(s). Then, the goal of the decision stage is to precisely locate the contours of the 3D regions set by the markers. This contour decision is performed by a 3D extension of the watershed transform. The anatomical structures taken into consideration and embedded into the atlas are brain, ventricles, corpus callosum, cerebellum, right and left hippocampus, medulla and midbrain. The hybrid method operates fully automatically and in 3D, successfully providing segmented brain structures. The quality of the segmentation has been studied in terms of the detected volume ratio by using kappa statistic and ROC analysis. Results of the method are shown and validated on a 3D MRI phantom. This study forms part of an on-going long term research aiming at the creation of a 3D probabilistic multi-purpose anatomical brain atlas.

  9. Development of hybrid 3-D hydrological modeling for the NCAR Community Earth System Model (CESM)

    SciTech Connect

    Zeng, Xubin; Troch, Peter; Pelletier, Jon; Niu, Guo-Yue; Gochis, David

    2015-11-15

    This is the Final Report of our four-year (3-year plus one-year no cost extension) collaborative project between the University of Arizona (UA) and the National Center for Atmospheric Research (NCAR). The overall objective of our project is to develop and evaluate the first hybrid 3-D hydrological model with a horizontal grid spacing of 1 km for the NCAR Community Earth System Model (CESM). We have made substantial progress in model development and evaluation, computational efficiencies and software engineering, and data development and evaluation, as discussed in Sections 2-4. Section 5 presents our success in data dissemination, while Section 6 discusses the scientific impacts of our work. Section 7 discusses education and mentoring success of our project, while Section 8 lists our relevant DOE services. All peer-reviewed papers that acknowledged this project are listed in Section 9. Highlights of our achievements include: • We have finished 20 papers (most published already) on model development and evaluation, computational efficiencies and software engineering, and data development and evaluation • The global datasets developed under this project have been permanently archived and publicly available • Some of our research results have already been implemented in WRF and CLM • Patrick Broxton and Michael Brunke have received their Ph.D. • PI Zeng has served on DOE proposal review panels and DOE lab scientific focus area (SFA) review panels

  10. 3D high-density localization microscopy using hybrid astigmatic/ biplane imaging and sparse image reconstruction.

    PubMed

    Min, Junhong; Holden, Seamus J; Carlini, Lina; Unser, Michael; Manley, Suliana; Ye, Jong Chul

    2014-11-01

    Localization microscopy achieves nanoscale spatial resolution by iterative localization of sparsely activated molecules, which generally leads to a long acquisition time. By implementing advanced algorithms to treat overlapping point spread functions (PSFs), imaging of densely activated molecules can improve the limited temporal resolution, as has been well demonstrated in two-dimensional imaging. However, three-dimensional (3D) localization of high-density data remains challenging since PSFs are far more similar along the axial dimension than the lateral dimensions. Here, we present a new, high-density 3D imaging system and algorithm. The hybrid system is implemented by combining astigmatic and biplane imaging. The proposed 3D reconstruction algorithm is extended from our state-of-the art 2D high-density localization algorithm. Using mutual coherence analysis of model PSFs, we validated that the hybrid system is more suitable than astigmatic or biplane imaging alone for 3D localization of high-density data. The efficacy of the proposed method was confirmed via simulation and real data of microtubules. Furthermore, we also successfully demonstrated fluorescent-protein-based live cell 3D localization microscopy with a temporal resolution of just 3 seconds, capturing fast dynamics of the endoplasmic recticulum.

  11. 2D-3D hybrid stabilized finite element method for tsunami runup simulations

    NASA Astrophysics Data System (ADS)

    Takase, S.; Moriguchi, S.; Terada, K.; Kato, J.; Kyoya, T.; Kashiyama, K.; Kotani, T.

    2016-09-01

    This paper presents a two-dimensional (2D)-three-dimensional (3D) hybrid stabilized finite element method that enables us to predict a propagation process of tsunami generated in a hypocentral region, which ranges from offshore propagation to runup to urban areas, with high accuracy and relatively low computational costs. To be more specific, the 2D shallow water equation is employed to simulate the propagation of offshore waves, while the 3D Navier-Stokes equation is employed for the runup in urban areas. The stabilized finite element method is utilized for numerical simulations for both of the 2D and 3D domains that are independently discretized with unstructured meshes. The multi-point constraint and transmission methods are applied to satisfy the continuity of flow velocities and pressures at the interface between the resulting 2D and 3D meshes, since neither their spatial dimensions nor node arrangements are consistent. Numerical examples are presented to demonstrate the performance of the proposed hybrid method to simulate tsunami behavior, including offshore propagation and runup to urban areas, with substantially lower computation costs in comparison with full 3D computations.

  12. Testing the hybrid-3D Hillslope Hydrological Model in a Real-World Controlled Environment

    NASA Astrophysics Data System (ADS)

    Hazenberg, P.; Broxton, P. D.; Gochis, D. J.; Niu, G. Y.; Pelletier, J. D.; Troch, P. A. A.; Zeng, X.

    2015-12-01

    Hillslopes play an important role for converting rainfall into runoff, and as such, influence theterrestrial dynamics of the Earth's climate system. Recently, we have developed a hybrid-3D (h3D) hillslope hydrological model that couples a 1D vertical soil column model with a lateral pseudo-2D saturated zone and overland flow model. The h3D model gives similar results as the CATchment HYdrological model (CATHY), which simulates the subsurface movement of water with the 3D Richards equation, though the runtime efficiency of the h3D model is about 2-3 orders of magnitude faster. In the current work, the ability of the h3D model to predict real-world hydrological dynamics is assessed using a number of recharge-drainage experiments within the Landscape Evolution Observatory (LEO) at the Biosphere 2 near Tucson, Arizona, USA. LEO offers accurate and high-resolution (both temporally and spatially) observations of the inputs, outputs and storage dynamics of several hillslopes. The level of detail of these observations is generally not possible with real-world hillslope studies. Therefore, LEO offers an optimal environment to test the h3D model. The h3D model captures the observed storage, baseflow, and overland flow dynamics of both a larger and a smaller hillslope. Furthermore, it simulates overland flow better than CATHY. The h3D model has difficulties correctly representing the height of the saturated zone close to the seepage face of the smaller hillslope, though. There is a gravel layer near this seepage face, and the numerical boundary condition of the h3D model is insufficient to capture the hydrological dynamics within this region. In addition, the h3D model is used to test the hypothesis that model parameters change through time due to the migration of soil particles during the recharge-drainage experiments. An in depth calibration of the h3D model parameters reveals that the best results are obtained by applying an event-based optimization procedure as compared

  13. Flight tests of a hybrid-centered integrated 3D perspective-view primary flight display

    NASA Astrophysics Data System (ADS)

    He, Gang; Feyereisen, Thea; Wilson, Blake; Wyatt, Sandy; Engels, Jary

    2006-05-01

    This paper describes flight tests of a Honeywell Synthetic Vision System (SVS) prototype operating in a hybrid-centered mode on a Primus Epic TM large format display. This novel hybrid mode effectively resolves some cognitive and perceptual human factors issues associated with traditional heading-up or track-up display modes. By integrating synthetic 3D perspective view with advanced Head-Up Display (HUD) symbology in this mode, the test results demonstrate that the hybrid display mode provides clear indications of current track and crab conditions, and is effective in overcoming flight guidance symbology collision and resultant ambiguity. The hybrid-centering SVS display concept is shown to be effective in all phases of flight and is particularly valuable during landing operations with a strong cross-wind. The recorded flight test data from Honeywell's prototype SVS concept at Reno, Nevada on board Honeywell Citation V aircraft will be discussed.

  14. Nanoscale Analysis of a Hierarchical Hybrid Solar Cell in 3D

    PubMed Central

    Divitini, Giorgio; Stenzel, Ole; Ghadirzadeh, Ali; Guarnera, Simone; Russo, Valeria; Casari, Carlo S; Bassi, Andrea Li; Petrozza, Annamaria; Di Fonzo, Fabio; Schmidt, Volker; Ducati, Caterina

    2014-01-01

    A quantitative method for the characterization of nanoscale 3D morphology is applied to the investigation of a hybrid solar cell based on a novel hierarchical nanostructured photoanode. A cross section of the solar cell device is prepared by focused ion beam milling in a micropillar geometry, which allows a detailed 3D reconstruction of the titania photoanode by electron tomography. It is found that the hierarchical titania nanostructure facilitates polymer infiltration, thus favoring intermixing of the two semiconducting phases, essential for charge separation. The 3D nanoparticle network is analyzed with tools from stochastic geometry to extract information related to the charge transport in the hierarchical solar cell. In particular, the experimental dataset allows direct visualization of the percolation pathways that contribute to the photocurrent. PMID:25834481

  15. Fluorescence in situ hybridization on 3D cultures of tumor cells.

    PubMed

    Meaburn, Karen J

    2010-01-01

    Genomes are spatially highly organized within interphase nuclei. Spatial genome organization is increasingly linked to genome function. Fluorescence in situ hybridization (FISH) allows the visualization of specific regions of the genome for spatial mapping. While most gene localization studies have been performed on cultured cells, genome organization is likely to be different in the context of tissues. Three-dimensional (3D) culture model systems provide a powerful tool to study the contribution of tissue organization to gene expression and organization. However, FISH on 3D cultures is technically more challenging than on monocultures. Here, we describe an optimized protocol for interphase DNA FISH on 3D cultures of the breast epithelial cell line MCF-10A.B2, which forms breast acini and can be used as a model for early breast cancer. PMID:20809324

  16. Interactive and Stereoscopic Hybrid 3D Viewer of Radar Data with Gesture Recognition

    NASA Astrophysics Data System (ADS)

    Goenetxea, Jon; Moreno, Aitor; Unzueta, Luis; Galdós, Andoni; Segura, Álvaro

    This work presents an interactive and stereoscopic 3D viewer of weather information coming from a Doppler radar. The hybrid system shows a GIS model of the regional zone where the radar is located and the corresponding reconstructed 3D volume weather data. To enhance the immersiveness of the navigation, stereoscopic visualization has been added to the viewer, using a polarized glasses based system. The user can interact with the 3D virtual world using a Nintendo Wiimote for navigating through it and a Nintendo Wii Nunchuk for giving commands by means of hand gestures. We also present a dynamic gesture recognition procedure that measures the temporal advance of the performed gesture postures. Experimental results show how dynamic gestures are effectively recognized so that a more natural interaction and immersive navigation in the virtual world is achieved.

  17. R3D Align web server for global nucleotide to nucleotide alignments of RNA 3D structures

    PubMed Central

    Rahrig, Ryan R.; Petrov, Anton I.; Leontis, Neocles B.; Zirbel, Craig L.

    2013-01-01

    The R3D Align web server provides online access to ‘RNA 3D Align’ (R3D Align), a method for producing accurate nucleotide-level structural alignments of RNA 3D structures. The web server provides a streamlined and intuitive interface, input data validation and output that is more extensive and easier to read and interpret than related servers. The R3D Align web server offers a unique Gallery of Featured Alignments, providing immediate access to pre-computed alignments of large RNA 3D structures, including all ribosomal RNAs, as well as guidance on effective use of the server and interpretation of the output. By accessing the non-redundant lists of RNA 3D structures provided by the Bowling Green State University RNA group, R3D Align connects users to structure files in the same equivalence class and the best-modeled representative structure from each group. The R3D Align web server is freely accessible at http://rna.bgsu.edu/r3dalign/. PMID:23716643

  18. Fabrication of 3D high aspect ratio PDMS microfluidic networks with a hybrid stamp.

    PubMed

    Kung, Yu-Chun; Huang, Kuo-Wei; Fan, Yu-Jui; Chiou, Pei-Yu

    2015-04-21

    We report a novel methodology for fabricating large-area, multilayer, thin-film, high aspect ratio, 3D microfluidic structures with through-layer vias and open channels that can be bonded between hard substrates. It is realized by utilizing a hybrid stamp with a thin plastic sheet embedded underneath a PDMS surface. This hybrid stamp solves an important edge protrusion issue during PDMS molding while maintaining necessary stamp elasticity to ensure the removal of PDMS residues at through-layer regions. Removing edge protrusion is a significant progress toward fabricating 3D structures since high aspect ratio PDMS structures with flat interfaces can be realized to facilitate multilayer stacking and bonding to hard substrates. Our method also allows for the fabrication of 3D deformable channels, which can lead to profound applications in electrokinetics, optofluidics, inertial microfluidics, and other fields where the shape of the channel cross section plays a key role in device physics. To demonstrate, as an example, we have fabricated a microfluidic channel by sandwiching two 20 μm wide, 80 μm tall PDMS membranes between two featureless ITO glass substrates. By applying electrical bias to the two ITO substrates and pressure to deform the thin membrane sidewalls, strong electric field enhancement can be generated in the center of a channel to enable 3D sheathless dielectrophoretic focusing of biological objects including mammalian cells and bacteria at a flow speed up to 14 cm s(-1).

  19. Development of hybrid 3-D hydrological modeling for the NCAR Community Earth System Model (CESM)

    SciTech Connect

    Zeng, Xubin; Troch, Peter; Pelletier, Jon; Niu, Guo-Yue; Gochis, David

    2015-11-15

    This is the Final Report of our four-year (3-year plus one-year no cost extension) collaborative project between the University of Arizona (UA) and the National Center for Atmospheric Research (NCAR). The overall objective of our project is to develop and evaluate the first hybrid 3-D hydrological model with a horizontal grid spacing of 1 km for the NCAR Community Earth System Model (CESM).

  20. Properties of lower-hybrid range wave activity at reconnection jet edge: 3D PIC simulations

    NASA Astrophysics Data System (ADS)

    Divin, Andrey; Khotyaintsev, Yuri; Vaivads, Andris; Andre, Mats; Lapenta, Giovanni; Markidis, Stefano

    2014-05-01

    Reconnection fronts are areas of intense currents and enhanced wave activity, since magnetic flux and plasma are piled up there when the accelerated flow encounters denser ambient current sheet. Observations and numerical simulations show that the fronts generate a variety of waves ranging from MHD frequencies up to lower hybrid frequency and above. In the present study we use 2D and 3D Particle-in-Cell (PIC) simulations to investigate the properties of the lower hybrid range waves developing at hot reconnected plasma - current sheet interface. Calculations are performed using implicit parallel code iPIC3D starting from conventional Harris current sheet. Initial evolution of the jet is simulated using 2D approach to save computational time, but 3D calculations are implemented at later stages in order to observe instability linear stage, saturation and transition to turbulence. Properties of the linear stage match closely theoretical predictions for the lower hybrid drift instability. During saturation, the mode produces intense electric fields (several Alfvén in electric fields normalized unit) that can provide an additional mechanism of electron heating at reconnection jet fronts.

  1. 3D kinetic simulations of the global interaction between the solar wind and the magnetosphere

    NASA Astrophysics Data System (ADS)

    Amaya, Jorge; Maneva, Yana; Deca, Jan; Lapenta, Giovanni

    2015-04-01

    We performed three dimensional simulations of the interaction between the solar wind and the magnetosphere, using the self-consistent fully kinetic code iPic3D. The main objective of our simulations is to link the global interaction phenomena to the local turbulence and reconnection processes in the magnetosphere. Other numerical approaches have been used before to study this problem, including MHD, hybrid and Vlasov codes. However, only particle-in-cell codes offer the possibility to study the kinetic effects of the diffusion regions of the Earth environment that drive the energy transfer from the solar wind to the magnetosphere. Previous attempts to perform such kinds of simulations were limited to unphysical thermal velocities of the ion and electron species, small simulation boxes or cell sizes that do not capture the local kinetic effects at the magnetopause. Using the implicit moment Particle-in-Cell approach we performed simulations that can capture these small scale effects and, at the same time, allow to study large scale phenomena such as the bow shock and the development of the magnetotail. We expect that these results will be used to maximize the impact of future space missions, such as THOR, MMS and BepiColombo, by improving our understanding of the planetary environment, from the conditions observed in the solar wind to the turbulence and reconnection processes downstream of the bow shock.

  2. Study of the internal magnetic field of Mercury through 3D hybrid simulations

    NASA Astrophysics Data System (ADS)

    Leclercq, Ludivine; Marcel Chanteur, Gerard; Modolo, Ronan; Leblanc, Francois; Schmidt, Carl; Langlais, Benoît; Thebault, Erwan

    2016-10-01

    In 1974, Mariner 10 discovered the intrinsic magnetic field of Mercury which interacts with the solar wind, leading to the formation of a magnetosphere. In spite of the recent MESSENGER observations, this magnetosphere remains quite unknown, especially in the Southern hemisphere. In order to improve our understanding of the Hermean magnetosphere, and to prepare the Bepi-Colombo mission (ESA/JAXA), we simulated the magnetized environment of Mercury using the model named LatHyS (LATMOS Hybrid Simulation). LatHyS is a 3D parallel multi-species hybrid code which has been applied to Mars, Titan and Ganymede, which has recently be improved by the implementation of a multi-grid method allowing to refine the spatial resolution near the planetary object (40 km in the case of Mercury). In order to investigate the Hermean environment, several hybrid simulations have been performed considering different internal field models, and results are compared with MESSENGER observations.

  3. Local-global alignment for finding 3D similarities in protein structures

    DOEpatents

    Zemla, Adam T.

    2011-09-20

    A method of finding 3D similarities in protein structures of a first molecule and a second molecule. The method comprises providing preselected information regarding the first molecule and the second molecule. Comparing the first molecule and the second molecule using Longest Continuous Segments (LCS) analysis. Comparing the first molecule and the second molecule using Global Distance Test (GDT) analysis. Comparing the first molecule and the second molecule using Local Global Alignment Scoring function (LGA_S) analysis. Verifying constructed alignment and repeating the steps to find the regions of 3D similarities in protein structures.

  4. Optimization of a Hybrid Magnetic Bearing for a Magnetically Levitated Blood Pump via 3-D FEA

    PubMed Central

    Cheng, Shanbao; Olles, Mark W.; Burger, Aaron F.; Day, Steven W.

    2011-01-01

    In order to improve the performance of a magnetically levitated (maglev) axial flow blood pump, three-dimensional (3-D) finite element analysis (FEA) was used to optimize the design of a hybrid magnetic bearing (HMB). Radial, axial, and current stiffness of multiple design variations of the HMB were calculated using a 3-D FEA package and verified by experimental results. As compared with the original design, the optimized HMB had twice the axial stiffness with the resulting increase of negative radial stiffness partially compensated for by increased current stiffness. Accordingly, the performance of the maglev axial flow blood pump with the optimized HMBs was improved: the maximum pump speed was increased from 6000 rpm to 9000 rpm (50%). The radial, axial and current stiffness of the HMB was found to be linear at nominal operational position from both 3-D FEA and empirical measurements. Stiffness values determined by FEA and empirical measurements agreed well with one another. The magnetic flux density distribution and flux loop of the HMB were also visualized via 3-D FEA which confirms the designers’ initial assumption about the function of this HMB. PMID:22065892

  5. Hybrid Three-Dimensional (3-D) Woven Thick Composite Architectures in Bending

    NASA Astrophysics Data System (ADS)

    Pankow, Mark; Quabili, Ashiq; Yen, Chian-Fong

    2013-11-01

    In this study, three 3-dimensional (3-D) woven composite materials were examined to determine how yarn tow configurations affect the flexural response of the structure. Woven fabric preforms were manufactured with a Z-fiber architecture in 2-3 in. thicknesses. These preforms contained S-2 Glass (AGY, Aiken, SC, USA), carbon, and Twaron (Teijin Aramid, Arnhem, The Netherlands) yarns in different architectures creating a hybrid material system. Due to the thickness of the material, these samples required a significant span length (30 in.). The results showed a change in the strength and degradation after failure with the addition of carbon layers in tension.

  6. Optical design of wavelength selective CPVT system with 3D/2D hybrid concentration

    NASA Astrophysics Data System (ADS)

    Ahmad, N.; Ijiro, T.; Yamada, N.; Kawaguchi, T.; Maemura, T.; Ohashi, H.

    2012-10-01

    Optical design of a concentrating photovoltaic/thermal (CPVT) system is carried out. Using wavelength-selective optics, the system demonstrates 3-D concentration onto a solar cell and 2-D concentration onto a thermal receiver. Characteristics of the two types of concentrator systems are examined with ray-tracing analysis. The first system is a glazed mirror-based concentrator system mounted on a 2-axis pedestal tracker. The size of the secondary optical element is minimized to decrease the cost of the system, and it has a wavelength-selective function for performing 3-D concentration onto a solar cell and 2-D concentration onto a thermal receiver. The second system is a non-glazed beamdown concentrator system containing parabolic mirrors in the lower part. The beam-down selective mirror performs 3-D concentration onto a solar cell placed above the beam-down selective mirror, and 2-D concentration down to a thermal receiver placed at the bottom level. The system is mounted on a two-axis carousel tracker. A parametric study is performed for those systems with different geometrical 2-D/3-D concentration ratios. Wavelength-selective optics such as hot/cold mirrors and spectrum-splitting technologies are taken into account in the analysis. Results show reduced heat load on the solar cell and increased total system efficiency compared to a non-selective CPV system. Requirements for the wavelength-selective properties are elucidated. It is also shown that the hybrid concept with 2-D concentration onto a thermal receiver and 3-D concentration onto a solar cell has an advantageous geometry because of the high total system efficiency and compatibility with the piping arrangement of the thermal receiver.

  7. Testing the hybrid-3-D hillslope hydrological model in a controlled environment

    NASA Astrophysics Data System (ADS)

    Hazenberg, P.; Broxton, P.; Gochis, D.; Niu, G.-Y.; Pangle, L. A.; Pelletier, J. D.; Troch, P. A.; Zeng, X.

    2016-02-01

    Hillslopes are important for converting rainfall into runoff, influencing the terrestrial dynamics of the Earth's climate system. Recently, we developed a hybrid-3-D (h3D) hillslope hydrological model that gives similar results as a full 3-D hydrological model but is up to 2-3 orders of magnitude faster computationally. Here h3D is assessed using a number of recharge-drainage experiments within the Landscape Evolution Observatory (LEO) with accurate and high-resolution (both temporally and spatially) observations of the inputs, outputs, and storage dynamics of several hillslopes. Such detailed measurements are generally not available for real-world hillslopes. Results show that the h3D model captures the observed storage, base flow, and overland flow dynamics of both the larger LEO and the smaller miniLEO hillslopes very well. Sensitivity tests are also performed to understand h3Ds difficulty in representing the height of the saturated zone close to the seepage face of the miniLEO hillslope. Results reveal that a temporally constant parameters set is able to simulate the response of the miniLEO for each individual event. However, when one focuses on the saturated zone dynamics at 0.15 m from the seepage face, a stepwise evolution of the optimal model parameter for the saturated lateral conductivity parameter of the gravel layer occurs. This evolution might be related to the migration of soil particles within the hillslope. However, it is currently unclear whether and where this takes place (in the seepage face or within the parts of the loamy sand soil).

  8. Global regular solutions for the 3D Zakharov-Kuznetsov equation posed on unbounded domains

    NASA Astrophysics Data System (ADS)

    Larkin, N. A.

    2015-09-01

    An initial-boundary value problem for the 3D Zakharov-Kuznetsov equation posed on unbounded domains is considered. Existence and uniqueness of a global regular solution as well as exponential decay of the H2-norm for small initial data are proven.

  9. The Use of Atomic Force Microscopy for 3D Analysis of Nucleic Acid Hybridization on Microarrays

    PubMed Central

    Dubrovin, E. V.; Presnova, G. V.; Rubtsova, M. Yu.; Egorov, A. M.; Grigorenko, V. G.; Yaminsky, I. V.

    2015-01-01

    Oligonucleotide microarrays are considered today to be one of the most efficient methods of gene diagnostics. The capability of atomic force microscopy (AFM) to characterize the three-dimensional morphology of single molecules on a surface allows one to use it as an effective tool for the 3D analysis of a microarray for the detection of nucleic acids. The high resolution of AFM offers ways to decrease the detection threshold of target DNA and increase the signal-to-noise ratio. In this work, we suggest an approach to the evaluation of the results of hybridization of gold nanoparticle-labeled nucleic acids on silicon microarrays based on an AFM analysis of the surface both in air and in liquid which takes into account of their three-dimensional structure. We suggest a quantitative measure of the hybridization results which is based on the fraction of the surface area occupied by the nanoparticles. PMID:26085952

  10. Initial Results From the 3D Hybrid Heliospheric Modeling System With Pickup Protons

    NASA Astrophysics Data System (ADS)

    Detman, T. R.; Intriligator, D.; Dryer, M.; Sun, W.; Deehr, C.; Intriligator, J.

    2008-12-01

    Interstellar neutral hydrogen flows into the heliosphere and becomes ionized by photoionization and by charge exchange with solar wind protons. These "pickup" protons cause a slowing and heating of the solar wind flow in the outer heliosphere. We are adding the physics of these processes to our time-dependent 3D Hybrid Heliospheric Modeling System. We plan to present initial results for the "Halloween" 2003 events, and to show comparisons with both ACE and Ulysses observations and with our previous results (without pickup protons). This work is sponsored by NASA Grant NNX08AE40G and by Carmel Research Center. Detman et al., 2006, A hybrid heliospheric modeling system: Background solar wind, J. Geophys. Res., V 111, doi:10.1029/2005JA011340

  11. Localizing Protein in 3D Neural Stem Cell Culture: a Hybrid Visualization Methodology

    PubMed Central

    Fai, Stephen; Bennett, Steffany A.L.

    2010-01-01

    The importance of 3-dimensional (3D) topography in influencing neural stem and progenitor cell (NPC) phenotype is widely acknowledged yet challenging to study. When dissociated from embryonic or post-natal brain, single NPCs will proliferate in suspension to form neurospheres. Daughter cells within these cultures spontaneously adopt distinct developmental lineages (neurons, oligodendrocytes, and astrocytes) over the course of expansion despite being exposed to the same extracellular milieu. This progression recapitulates many of the stages observed over the course of neurogenesis and gliogenesis in post-natal brain and is often used to study basic NPC biology within a controlled environment. Assessing the full impact of 3D topography and cellular positioning within these cultures on NPC fate is, however, difficult. To localize target proteins and identify NPC lineages by immunocytochemistry, free-floating neurospheres must be plated on a substrate or serially sectioned. This processing is required to ensure equivalent cell permeabilization and antibody access throughout the sphere. As a result, 2D epifluorescent images of cryosections or confocal reconstructions of 3D Z-stacks can only provide spatial information about cell position within discrete physical or digital 3D slices and do not visualize cellular position in the intact sphere. Here, to reiterate the topography of the neurosphere culture and permit spatial analysis of protein expression throughout the entire culture, we present a protocol for isolation, expansion, and serial sectioning of post-natal hippocampal neurospheres suitable for epifluorescent or confocal immunodetection of target proteins. Connexin29 (Cx29) is analyzed as an example. Next, using a hybrid of graphic editing and 3D modelling softwares rigorously applied to maintain biological detail, we describe how to re-assemble the 3D structural positioning of these images and digitally map labelled cells within the complete neurosphere. This

  12. 3D magnetospheric parallel hybrid multi-grid method applied to planet-plasma interactions

    NASA Astrophysics Data System (ADS)

    Leclercq, L.; Modolo, R.; Leblanc, F.; Hess, S.; Mancini, M.

    2016-03-01

    We present a new method to exploit multiple refinement levels within a 3D parallel hybrid model, developed to study planet-plasma interactions. This model is based on the hybrid formalism: ions are kinetically treated whereas electrons are considered as a inertia-less fluid. Generally, ions are represented by numerical particles whose size equals the volume of the cells. Particles that leave a coarse grid subsequently entering a refined region are split into particles whose volume corresponds to the volume of the refined cells. The number of refined particles created from a coarse particle depends on the grid refinement rate. In order to conserve velocity distribution functions and to avoid calculations of average velocities, particles are not coalesced. Moreover, to ensure the constancy of particles' shape function sizes, the hybrid method is adapted to allow refined particles to move within a coarse region. Another innovation of this approach is the method developed to compute grid moments at interfaces between two refinement levels. Indeed, the hybrid method is adapted to accurately account for the special grid structure at the interfaces, avoiding any overlapping grid considerations. Some fundamental test runs were performed to validate our approach (e.g. quiet plasma flow, Alfven wave propagation). Lastly, we also show a planetary application of the model, simulating the interaction between Jupiter's moon Ganymede and the Jovian plasma.

  13. Dense 3d Point Cloud Generation from Uav Images from Image Matching and Global Optimazation

    NASA Astrophysics Data System (ADS)

    Rhee, S.; Kim, T.

    2016-06-01

    3D spatial information from unmanned aerial vehicles (UAV) images is usually provided in the form of 3D point clouds. For various UAV applications, it is important to generate dense 3D point clouds automatically from over the entire extent of UAV images. In this paper, we aim to apply image matching for generation of local point clouds over a pair or group of images and global optimization to combine local point clouds over the whole region of interest. We tried to apply two types of image matching, an object space-based matching technique and an image space-based matching technique, and to compare the performance of the two techniques. The object space-based matching used here sets a list of candidate height values for a fixed horizontal position in the object space. For each height, its corresponding image point is calculated and similarity is measured by grey-level correlation. The image space-based matching used here is a modified relaxation matching. We devised a global optimization scheme for finding optimal pairs (or groups) to apply image matching, defining local match region in image- or object- space, and merging local point clouds into a global one. For optimal pair selection, tiepoints among images were extracted and stereo coverage network was defined by forming a maximum spanning tree using the tiepoints. From experiments, we confirmed that through image matching and global optimization, 3D point clouds were generated successfully. However, results also revealed some limitations. In case of image-based matching results, we observed some blanks in 3D point clouds. In case of object space-based matching results, we observed more blunders than image-based matching ones and noisy local height variations. We suspect these might be due to inaccurate orientation parameters. The work in this paper is still ongoing. We will further test our approach with more precise orientation parameters.

  14. Implementation of 3D wave forcing terms in the HYbrid Coordinate Ocean Model

    NASA Astrophysics Data System (ADS)

    Ody, Cédric; Filipot, Jean-François; Pichon, Annick; Lathuilière, Cyril; Baraille, Rémy

    2013-04-01

    Waves may influence the circulation in coastal regions at temporal and spatial scales that are larger than the periods and wavelengths of the waves respectively. The setup of the mean sea surface level or longshore currents are two examples of coastal processes that are generated by the mean effects of waves. Although simple models have been shown to provide reasonable estimates of setup and mean currents, the prediction of such wave-induced mechanisms has been improved since the recent development of theories on 3D wave-current interactions. Amongst these theories, the works of Ardhuin et al. (2008) and Mc Williams et al. (2004) give rise to forcing terms that may be used in existing circulation models. Under some assumptions on the shear of the mean current, the two previous works derive similar expressions for the wave forcing terms. In this talk, we will detail and discuss the implementation of these 3D terms in the HYbrid Coordinate Ocean Model (HYCOM, Bleck 2002). We will focus in particular on the hybrid and layered features of the code. The hybrid coordinate, which allows to use distinct vertical coordinates in a same simulation, requires to reformulate the wave forcing terms with a generalised vertical coordinate. Then, these terms must be averaged on each layer of the water column. Two academic tests are investigated to validate the numerical implementation : the gently sloping bottom of Ardhuin (2008) and the plane beach of Haas and Warner (2009). Forcing terms are calculated with simple numerical methods under classical assumptions on conservation of wave properties. The results obtained with distinct configurations are shown to agree with the analytical or numerical known solutions. To conclude, we will discuss the impact of wetting and drying in numerical simulations.

  15. Compilation of 3D global conductivity model of the Earth for space weather applications

    NASA Astrophysics Data System (ADS)

    Alekseev, Dmitry; Kuvshinov, Alexey; Palshin, Nikolay

    2015-07-01

    We have compiled a global three-dimensional (3D) conductivity model of the Earth with an ultimate goal to be used for realistic simulation of geomagnetically induced currents (GIC), posing a potential threat to man-made electric systems. Bearing in mind the intrinsic frequency range of the most intense disturbances (magnetospheric substorms) with typical periods ranging from a few minutes to a few hours, the compiled 3D model represents the structure in depth range of 0-100 km, including seawater, sediments, earth crust, and partly the lithosphere/asthenosphere. More explicitly, the model consists of a series of spherical layers, whose vertical and lateral boundaries are established based on available data. To compile a model, global maps of bathymetry, sediment thickness, and upper and lower crust thicknesses as well as lithosphere thickness are utilized. All maps are re-interpolated on a common grid of 0.25×0.25 degree lateral spacing. Once the geometry of different structures is specified, each element of the structure is assigned either a certain conductivity value or conductivity versus depth distribution, according to available laboratory data and conversion laws. A numerical formalism developed for compilation of the model, allows for its further refinement by incorporation of regional 3D conductivity distributions inferred from the real electromagnetic data. So far we included into our model four regional conductivity models, available from recent publications, namely, surface conductance model of Russia, and 3D conductivity models of Fennoscandia, Australia, and northwest of the United States.

  16. 3D networked graphene-ferromagnetic hybrids for fast shape memory polymers with enhanced mechanical stiffness and thermal conductivity.

    PubMed

    Lee, Sang-Heon; Jung, Jung-Hwan; Oh, Il-Kwon

    2014-10-15

    A novel 3D networked graphene-ferromagnetic hybrid can be easily fabricated using one-step microwave irradiation. By incorporating this hybrid material into shape memory polymers, the synergistic effects of fast speed and the enhancement of thermal conductivity and mechanical stiffness can be achieved. This can be broadly applicable to designing magneto-responsive shape memory polymers for multifunction applications.

  17. QUASI-OPTICAL 3-dB HYBRID FOR FUTURE HIGH-ENERGY ACCELERATORS

    SciTech Connect

    Jay L. Hirshfield

    2005-12-15

    Phase-controlled wave combiners-commutators and isolators for protecting rf sources against reflection from the accelerating structure can be built using a 3-dB hybrid built around a metallic grating used in a ''magic-Y'' configuration. Models of the magic-Y were designed and tested, both at 34.272 GHz using the Omega-P Ka-band magnicon, and at 11.424 GHz using the Omega-P/NRL X-band magnicon. All elements of the magic-Y were optimized analytically and numerically. A non-vacuum 34 GHz model of the magic Y was built and tested experimentally at a low power. An engineering design for the high power (vacuum) compressor was configured. Similar steps were taken for the 11-GHz version.

  18. 3D hybrid simulations with gyrokinetic particle ions and fluid electrons

    SciTech Connect

    Belova, E.V.; Park, W.; Fu, G.Y.; Strauss, H.R.; Sugiyama, L.E.

    1998-12-31

    The previous hybrid MHD/particle model (MH3D-K code) represented energetic ions as gyrokinetic (or drift-kinetic) particles coupled to MHD equations using the pressure or current coupling scheme. A small energetic to bulk ion density ratio was assumed, n{sub h}/n{sub b} {much_lt} 1, allowing the neglect of the energetic ion perpendicular inertia in the momentum equation and the use of MHD Ohm`s law E = {minus}v{sub b} {times} B. A generalization of this model in which all ions are treated as gyrokinetic/drift-kinetic particles and fluid description is used for the electron dynamics is considered in this paper.

  19. Variational formulation of hybrid problems for fully 3-D transonic flow with shocks in rotor

    NASA Technical Reports Server (NTRS)

    Liu, Gao-Lian

    1991-01-01

    Based on previous research, the unified variable domain variational theory of hybrid problems for rotor flow is extended to fully 3-D transonic rotor flow with shocks, unifying and generalizing the direct and inverse problems. Three variational principles (VP) families were established. All unknown boundaries and flow discontinuities (such as shocks, free trailing vortex sheets) are successfully handled via functional variations with variable domain, converting almost all boundary and interface conditions, including the Rankine Hugoniot shock relations, into natural ones. This theory provides a series of novel ways for blade design or modification and a rigorous theoretical basis for finite element applications and also constitutes an important part of the optimal design theory of rotor bladings. Numerical solutions to subsonic flow by finite elements with self-adapting nodes given in Refs., show good agreement with experimental results.

  20. ASICs in nanometer and 3D technologies for readout of hybrid pixel detectors

    NASA Astrophysics Data System (ADS)

    Maj, Piotr; Grybos, Pawel; Kmon, Piotr; Szczygiel, Robert

    2013-07-01

    Hybrid pixel detectors working in a single photon counting mode are very attractive solutions for material science and medical X-ray imaging applications. Readout electronics of these detectors has to match the geometry of pixel detectors with an area of readout channel of 100 μm × 100 μm (or even less) and very small power consumption (a few tens of μW). New solutions of readout ASICs are going into directions of better spatial resolutions, higher data throughput and more advanced functionality. We report on the design and measurement results of two pixel prototype ASICs in nanometer technology and 3D technology which offer fast signal processing, low noise performance and advanced functionality per single readout pixel cell.

  1. 3D Ag/ZnO hybrids for sensitive surface-enhanced Raman scattering detection

    NASA Astrophysics Data System (ADS)

    Huang, Chenyue; Xu, Chunxiang; Lu, Junfeng; Li, Zhaohui; Tian, Zhengshan

    2016-03-01

    To combine the surface plasma resonance of metal and local field enhancement in metal/semiconductor interface, Ag nanoparticles (NPs) were assembled on a ZnO nanorod array which was grown by hydrothermally on carbon fibers. The construction of dimensional (3D) Surface-Enhanced Raman Scattering (SERS) substrate is used for the sensitive detection of organic pollutants with the advantages such as facile synthesis, short detection time and low cost. The hybrid substrate was manifested a high sensitivity to phenol red at a lower concentration of 1 × 10-9 M and a higher enhancement factor of 3.18 × 109. Moreover, the ZnO nanostructures decorated with Ag NPs were demonstrated self-cleaning function under UV irradiation via photocatalytic degradation of the analytic molecules. The fabrication process of the materials and sensors, optimization of the SERS behaviors for different sized Ag NPs, the mechanism of SERS and recovery were presented with a detailed discussion.

  2. Analysis of hybrid dielectric-plasmonic slot waveguide structures with 3D Fourier Modal Methods

    NASA Astrophysics Data System (ADS)

    Ctyroky, J.; Kwiecien, P.; Richter, I.

    2013-03-01

    Recently, plasmonic waveguides have been intensively studied as promising basic building blocks for the construction of extremely compact photonic devices with subwavelength characteristic dimensions. A number of different types of plasmonic waveguide structures have been recently proposed, theoretically analyzed, and their properties experimentally verified. The fundamental trade-off in the design of plasmonic waveguides for potential application in information technologies lies in the contradiction between their mode field confinement and propagation loss: the higher confinement, the higher loss, and vice versa. Various definitions of figures of merit of plasmonic waveguides have been also introduced for the characterization of their properties with a single quantity. In this contribution, we theoretically analyze one specific type of a plasmonic waveguide - the hybrid dielectric-loaded plasmonic waveguide, or - as we call it in this paper - the hybrid dielectric-plasmonic slot waveguide, which exhibits very strong field confinement combined with acceptable losses allowing their application in some integrated plasmonic devices. In contrast to the structures analyzed previously, our structure makes use of a single low-index dielectric only. We first define the effective area of this waveguide type, and using waveguide parameters close to the optimum we analyze several waveguide devices as directional couplers, multimode interference couplers (MMI), and the Mach-Zehnder interferometer based on the MMI couplers. For the full-vector 3D analysis of these structures, we use modelling tools developed in-house on the basis of the Fourier Modal Method (FMM). Our results thus serve to a dual purpose: they confirm that (i) these structures represent promising building blocks of plasmonic devices, and (ii) our FMM codes are capable of efficient 3D vector modelling of plasmonic waveguide devices.

  3. External force back-projective composition and globally deformable optimization for 3-D coronary artery reconstruction

    NASA Astrophysics Data System (ADS)

    Yang, Jian; Cong, Weijian; Chen, Yang; Fan, Jingfan; Liu, Yue; Wang, Yongtian

    2014-02-01

    The clinical value of the 3D reconstruction of a coronary artery is important for the diagnosis and intervention of cardiovascular diseases. This work proposes a method based on a deformable model for reconstructing coronary arteries from two monoplane angiographic images acquired from different angles. First, an external force back-projective composition model is developed to determine the external force, for which the force distributions in different views are back-projected to the 3D space and composited in the same coordinate system based on the perspective projection principle of x-ray imaging. The elasticity and bending forces are composited as an internal force to maintain the smoothness of the deformable curve. Second, the deformable curve evolves rapidly toward the true vascular centerlines in 3D space and angiographic images under the combination of internal and external forces. Third, densely matched correspondence among vessel centerlines is constructed using a curve alignment method. The bundle adjustment method is then utilized for the global optimization of the projection parameters and the 3D structures. The proposed method is validated on phantom data and routine angiographic images with consideration for space and re-projection image errors. Experimental results demonstrate the effectiveness and robustness of the proposed method for the reconstruction of coronary arteries from two monoplane angiographic images. The proposed method can achieve a mean space error of 0.564 mm and a mean re-projection error of 0.349 mm.

  4. Single-Particle Cryo-EM and 3D Reconstruction of Hybrid Nanoparticles with Electron-Dense Components.

    PubMed

    Yu, Guimei; Yan, Rui; Zhang, Chuan; Mao, Chengde; Jiang, Wen

    2015-10-01

    Single-particle cryo-electron microscopy (cryo-EM), accompanied with 3D reconstruction, is a broadly applicable tool for the structural characterization of macromolecules and nanoparticles. Recently, the cryo-EM field has pushed the limits of this technique to higher resolutions and samples of smaller molecular mass, however, some samples still present hurdles to this technique. Hybrid particles with electron-dense components, which have been studied using single-particle cryo-EM yet with limited success in 3D reconstruction due to the interference caused by electron-dense elements, constitute one group of such challenging samples. To process such hybrid particles, a masking method is developed in this work to adaptively remove pixels arising from electron-dense portions in individual projection images while maintaining maximal biomass signals for subsequent 2D alignment, 3D reconstruction, and iterative refinements. As demonstrated by the success in 3D reconstruction of an octahedron DNA/gold hybrid particle, which has been previously published without a 3D reconstruction, the devised strategy that combines adaptive masking and standard single-particle 3D reconstruction approach has overcome the hurdle of electron-dense elements interference, and is generally applicable to cryo-EM structural characterization of most, if not all, hybrid nanomaterials with electron-dense components.

  5. Earthscape, a Multi-Purpose Interactive 3d Globe Viewer for Hybrid Data Visualization and Analysis

    NASA Astrophysics Data System (ADS)

    Sarthou, A.; Mas, S.; Jacquin, M.; Moreno, N.; Salamon, A.

    2015-08-01

    The hybrid visualization and interaction tool EarthScape is presented here. The software is able to display simultaneously LiDAR point clouds, draped videos with moving footprint, volume scientific data (using volume rendering, isosurface and slice plane), raster data such as still satellite images, vector data and 3D models such as buildings or vehicles. The application runs on touch screen devices such as tablets. The software is based on open source libraries, such as OpenSceneGraph, osgEarth and OpenCV, and shader programming is used to implement volume rendering of scientific data. The next goal of EarthScape is to perform data analysis using ENVI Services Engine, a cloud data analysis solution. EarthScape is also designed to be a client of Jagwire which provides multisource geo-referenced video fluxes. When all these components will be included, EarthScape will be a multi-purpose platform that will provide at the same time data analysis, hybrid visualization and complex interactions. The software is available on demand for free at france@exelisvis.com.

  6. Global 3-d weather models for the atmospheric correction of gravity time series

    NASA Astrophysics Data System (ADS)

    Klügel, Thomas; Wziontek, Hartmut

    2016-04-01

    The use of 3-dimensional weather models allows for an effective reduction of atmospheric effects in gravity time series. In the past the BKG service Atmacs (Atmospheric Attraction Computation Service) provided 3-d atmospheric correction time series only for European stations of the International Geodynamics and Earth Tide Service (IGETS, formerly Global Geodynamics Project, GGP), which are based on the high resolution regional model COSMO-EU of the German Weather Service (DWD). The provision of 3-d density data from the global weather models GME (20 km resolution) and most recently ICON (13 km resolution) by the DWD now allows the computation of 3-d atmospheric correction time series for all IGETS stations worldwide. Due to the triangular grid structure, a different procedure for mass elements close to the computation point is necessary. By increasing the spatial resolution towards the computation point by linear interpolation of the grid values, the use of a point mass approach became possible with an approximation error below 0.3 nm/s2. This approach also allows to consider horizontal density gradients and a tilted model surface of the innermost cells. By means of a variance reduction at different frequency bands a significant improvement of the atmospheric correction can be demonstrated at many IGETS stations. The limited temporal resolution of recently 3 hours can be improved by the user by including local air pressure records using a remove-restore technique. Atmospheric correction time series are online available at http://atmacs.bkg.bund.de.

  7. Effects of Na+ and He+ pickup ions on the lunar plasma environment: 3D hybrid modeling

    NASA Astrophysics Data System (ADS)

    Lipatov, A. S.; Cooper, J. F.; Sittler, E. C.; Hartle, R. E.; Sarantos, M.

    2011-12-01

    The hybrid kinetic model used here supports comprehensive simulation of the interaction between different spatial and energetic elements of the moon-solar wind-magnetosphere of the Earth system. There is a set of MHD,kinetic, hybrid, drift kinetic, electrostatic and full kinetic modeling of the lunar plasma environment [1]. However, observations show the existence of several species of the neutrals and pickup ions like Na, He, K, O etc., (see e.g., [2,3,4]). The solar wind parameters are chosen from the ARTEMIS observations [5]. The Na+, He+ lunar exosphere's parameters are chosen from [6,7]. The hybrid kinetic model allows us to take into account the finite gyroradius effects of pickup ions and to correctly estimate the ions velocity distribution and the fluxes along the magnetic field, and on the lunar surface. Modeling shows the formation of the asymmetric Mach cone, the structuring of the pickup ion tails, and presents another type of lunar-solar wind interaction. We will compare the results of our modeling with observed distributions. References [1] Lipatov, A.S., and Cooper, J.F., Hybrid kinetic modeling of the Lunar plasma environment: Past, present and future. In: Lunar Dust, Plasma and Atmosphere: The Next Steps, January 27-29, 2010, Boulder, Colorado, Abstracts/lpa2010.colorado.edu/. [2] Potter, A.E., and Morgan, T.H., Discovery of sodium and potassium vapor in the atmosphere of the Moon, Science, 241, 675-680, doi:10.1126/science.241.4866.675, 1988. [3] Tyler, A.L., et al., Observations of sodium in the tenuous lunar atmosphere, Geophys. Res. Lett., 15(10), 1141-1144, doi:10.1029/GL015i010p01141, 1988. [4] Tanaka, T., et al., First in situ observation of the Moon-originating ions in the Earth's Magnetosphere by MAP-PACE on SELENE (KAGUYA), Geophys. Res. Lett., 36, L22106, doi:10.1029/2009GL040682, 2009. [5] Wiehle, S., et al., First Lunar Wake Passage of ARTEMIS: Discrimination of Wake Effects and Solar Wind Fluctuations by 3D Hybrid Simulations, Planet

  8. 3D Reconstruction of Interplanetary Scintillation (IPS) Remote-Sensing Data: Global Solar Wind Boundaries for Driving 3D-MHD Models

    NASA Astrophysics Data System (ADS)

    Yu, H.-S.; Jackson, B. V.; Hick, P. P.; Buffington, A.; Odstrcil, D.; Wu, C.-C.; Davies, J. A.; Bisi, M. M.; Tokumaru, M.

    2015-09-01

    The University of California, San Diego, time-dependent analyses of the heliosphere provide three-dimensional (3D) reconstructions of solar wind velocities and densities from observations of interplanetary scintillation (IPS). Using data from the Solar-Terrestrial Environment Laboratory, Japan, these reconstructions provide a real-time prediction of the global solar-wind density and velocity throughout the whole heliosphere with a temporal cadence of about one day (ips.ucsd.edu). Updates to this modeling effort continue: in the present article, near-Sun results extracted from the time-dependent 3D reconstruction are used as inner boundary conditions to drive 3D-MHD models ( e.g. ENLIL and H3D-MHD). This allows us to explore the differences between the IPS kinematic-model data-fitting procedure and current 3D-MHD modeling techniques. The differences in these techniques provide interesting insights into the physical principles governing the expulsion of coronal mass ejections (CMEs). Here we detail for the first time several specific CMEs and an induced shock that occurred in September 2011 that demonstrate some of the issues resulting from these analyses.

  9. 3D Higher Order Modeling in the BEM/FEM Hybrid Formulation

    NASA Technical Reports Server (NTRS)

    Fink, P. W.; Wilton, D. R.

    2000-01-01

    Higher order divergence- and curl-conforming bases have been shown to provide significant benefits, in both convergence rate and accuracy, in the 2D hybrid finite element/boundary element formulation (P. Fink and D. Wilton, National Radio Science Meeting, Boulder, CO, Jan. 2000). A critical issue in achieving the potential for accuracy of the approach is the accurate evaluation of all matrix elements. These involve products of high order polynomials and, in some instances, singular Green's functions. In the 2D formulation, the use of a generalized Gaussian quadrature method was found to greatly facilitate the computation and to improve the accuracy of the boundary integral equation self-terms. In this paper, a 3D, hybrid electric field formulation employing higher order bases and higher order elements is presented. The improvements in convergence rate and accuracy, compared to those resulting from lower order modeling, are established. Techniques developed to facilitate the computation of the boundary integral self-terms are also shown to improve the accuracy of these terms. Finally, simple preconditioning techniques are used in conjunction with iterative solution procedures to solve the resulting linear system efficiently. In order to handle the boundary integral singularities in the 3D formulation, the parent element- either a triangle or rectangle-is subdivided into a set of sub-triangles with a common vertex at the singularity. The contribution to the integral from each of the sub-triangles is computed using the Duffy transformation to remove the singularity. This method is shown to greatly facilitate t'pe self-term computation when the bases are of higher order. In addition, the sub-triangles can be further divided to achieve near arbitrary accuracy in the self-term computation. An efficient method for subdividing the parent element is presented. The accuracy obtained using higher order bases is compared to that obtained using lower order bases when the number

  10. Tissue in Cube: In Vitro 3D Culturing Platform with Hybrid Gel Cubes for Multidirectional Observations.

    PubMed

    Hagiwara, Masaya; Kawahara, Tomohiro; Nobata, Rina

    2016-07-01

    An in vitro 3D culturing platform enabling multidirectional observations of 3D biosamples is presented. The 3D structure of biosamples can be recognized without fluorescence. The cubic platform employs two types of hydrogels that are compatible with conventional culture dishes or well plates, facilitating growth in culture, ease of handling, and viewing at multiple angles. PMID:27128576

  11. Tissue in Cube: In Vitro 3D Culturing Platform with Hybrid Gel Cubes for Multidirectional Observations.

    PubMed

    Hagiwara, Masaya; Kawahara, Tomohiro; Nobata, Rina

    2016-07-01

    An in vitro 3D culturing platform enabling multidirectional observations of 3D biosamples is presented. The 3D structure of biosamples can be recognized without fluorescence. The cubic platform employs two types of hydrogels that are compatible with conventional culture dishes or well plates, facilitating growth in culture, ease of handling, and viewing at multiple angles.

  12. Global regularity to the 3D MHD equations with large initial data in bounded domains

    NASA Astrophysics Data System (ADS)

    Yu, Haibo

    2016-08-01

    This paper considers the global regularity to the 3D incompressible MHD equations with large initial data in bounded domains. Let μ, ν, u, and b denote the viscosity coefficient, magnetic diffusivity, velocity field, and magnetic field, respectively. We construct new systems for (u - b) and (u + b) to overcome the difficulties caused by the large initial data. It is shown that ↑" separators=" ( u , b ) ↑ H 1 is globally bounded as long as ↑" separators=" ( u0 - b 0 ) ↑ H 1 + |" separators=" μ - ν | ( μ + ν ) - 1 or ↑" separators=" ( u0 + b 0 ) ↑ H 1 + |" separators=" μ - ν | ( μ + ν ) - 1 is sufficiently small, which indicates that the Navier-Stokes equations can be regularized by the magnetic field.

  13. Phosphonate-functionalized large pore 3-D cubic mesoporous (KIT-6) hybrid as highly efficient actinide extracting agent.

    PubMed

    Lebed, Pablo J; de Souza, Kellen; Bilodeau, François; Larivière, Dominic; Kleitz, Freddy

    2011-11-01

    A new type of radionuclide extraction material is reported based on phosphonate functionalities covalently anchored on the mesopore surface of 3-D cubic mesoporous silica (KIT-6). The easily prepared nanoporous hybrid shows largely superior performance in selective sorption of uranium and thorium as compared to the U/TEVA commercial resin and 2-D hexagonal SBA-15 equivalent.

  14. Two-photon polymerization of 3-D zirconium oxide hybrid scaffolds for long-term stem cell growth.

    PubMed

    Skoog, Shelby A; Nguyen, Alexander K; Kumar, Girish; Zheng, Jiwen; Goering, Peter L; Koroleva, Anastasia; Chichkov, Boris N; Narayan, Roger J

    2014-06-01

    Two-photon polymerization is a technique that involves simultaneous absorption of two photons from a femtosecond laser for selective polymerization of a photosensitive material. In this study, two-photon polymerization was used for layer-by-layer fabrication of 3-D scaffolds composed of an inorganic-organic zirconium oxide hybrid material. Four types of scaffold microarchitectures were created, which exhibit layers of parallel line features at various orientations as well as pores between the line features. Long-term cell culture studies involving human bone marrow stromal cells were conducted using these 3-D scaffolds. Cellular adhesion and proliferation were demonstrated on all of the scaffold types; tissuelike structure was shown to span the pores. This study indicates that two-photon polymerization may be used to create microstructured scaffolds out of an inorganic-organic zirconium oxide hybrid material for use in 3-D tissue culture systems.

  15. A global 3D P-velocity model of the Earth's crust and mantle for improved event location : SALSA3D.

    SciTech Connect

    Young, Christopher John; Steck, Lee K.; Phillips, William Scott; Ballard, Sanford; Chang, Marcus C.; Rowe, Charlotte A.; Encarnacao, Andre Villanova; Begnaud, Michael A.; Hipp, James Richard

    2010-07-01

    To test the hypothesis that high quality 3D Earth models will produce seismic event locations which are more accurate and more precise, we are developing a global 3D P wave velocity model of the Earth's crust and mantle using seismic tomography. In this paper, we present the most recent version of our model, SALSA3D version 1.5, and demonstrate its ability to reduce mislocations for a large set of realizations derived from a carefully chosen set of globally-distributed ground truth events. Our model is derived from the latest version of the Ground Truth (GT) catalog of P and Pn travel time picks assembled by Los Alamos National Laboratory. To prevent over-weighting due to ray path redundancy and to reduce the computational burden, we cluster rays to produce representative rays. Reduction in the total number of ray paths is {approx}50%. The model is represented using the triangular tessellation system described by Ballard et al. (2009), which incorporates variable resolution in both the geographic and radial dimensions. For our starting model, we use a simplified two layer crustal model derived from the Crust 2.0 model over a uniform AK135 mantle. Sufficient damping is used to reduce velocity adjustments so that ray path changes between iterations are small. We obtain proper model smoothness by using progressive grid refinement, refining the grid only around areas with significant velocity changes from the starting model. At each grid refinement level except the last one we limit the number of iterations to prevent convergence thereby preserving aspects of broad features resolved at coarser resolutions. Our approach produces a smooth, multi-resolution model with node density appropriate to both ray coverage and the velocity gradients required by the data. This scheme is computationally expensive, so we use a distributed computing framework based on the Java Parallel Processing Framework, providing us with {approx}400 processors. Resolution of our model is assessed

  16. SALSA3D : a global 3D p-velocity model of the Earth's crust and mantle for improved event location.

    SciTech Connect

    Encarnacao, Andre Villanova; Begnaud, Michael A.; Rowe, Charlotte A.; Young, Christopher John; Chang, Marcus C.; Ballard, Sally C.; Hipp, James Richard

    2010-06-01

    To test the hypothesis that high quality 3D Earth models will produce seismic event locations which are more accurate and more precise, we are developing a global 3D P wave velocity model of the Earth's crust and mantle using seismic tomography. In this paper, we present the most recent version of our model, SALSA3D version 1.5, and demonstrate its ability to reduce mislocations for a large set of realizations derived from a carefully chosen set of globally-distributed ground truth events. Our model is derived from the latest version of the Ground Truth (GT) catalog of P and Pn travel time picks assembled by Los Alamos National Laboratory. To prevent over-weighting due to ray path redundancy and to reduce the computational burden, we cluster rays to produce representative rays. Reduction in the total number of ray paths is {approx}50%. The model is represented using the triangular tessellation system described by Ballard et al. (2009), which incorporates variable resolution in both the geographic and radial dimensions. For our starting model, we use a simplified two layer crustal model derived from the Crust 2.0 model over a uniform AK135 mantle. Sufficient damping is used to reduce velocity adjustments so that ray path changes between iterations are small. We obtain proper model smoothness by using progressive grid refinement, refining the grid only around areas with significant velocity changes from the starting model. At each grid refinement level except the last one we limit the number of iterations to prevent convergence thereby preserving aspects of broad features resolved at coarser resolutions. Our approach produces a smooth, multi-resolution model with node density appropriate to both ray coverage and the velocity gradients required by the data. This scheme is computationally expensive, so we use a distributed computing framework based on the Java Parallel Processing Framework, providing us with {approx}400 processors. Resolution of our model is assessed

  17. Ultra-fast hybrid CPU-GPU multiple scatter simulation for 3-D PET.

    PubMed

    Kim, Kyung Sang; Son, Young Don; Cho, Zang Hee; Ra, Jong Beom; Ye, Jong Chul

    2014-01-01

    Scatter correction is very important in 3-D PET reconstruction due to a large scatter contribution in measurements. Currently, one of the most popular methods is the so-called single scatter simulation (SSS), which considers single Compton scattering contributions from many randomly distributed scatter points. The SSS enables a fast calculation of scattering with a relatively high accuracy; however, the accuracy of SSS is dependent on the accuracy of tail fitting to find a correct scaling factor, which is often difficult in low photon count measurements. To overcome this drawback as well as to improve accuracy of scatter estimation by incorporating multiple scattering contribution, we propose a multiple scatter simulation (MSS) based on a simplified Monte Carlo (MC) simulation that considers photon migration and interactions due to photoelectric absorption and Compton scattering. Unlike the SSS, the MSS calculates a scaling factor by comparing simulated prompt data with the measured data in the whole volume, which enables a more robust estimation of a scaling factor. Even though the proposed MSS is based on MC, a significant acceleration of the computational time is possible by using a virtual detector array with a larger pitch by exploiting that the scatter distribution varies slowly in spatial domain. Furthermore, our MSS implementation is nicely fit to a parallel implementation using graphic processor unit (GPU). In particular, we exploit a hybrid CPU-GPU technique using the open multiprocessing and the compute unified device architecture, which results in 128.3 times faster than using a single CPU. Overall, the computational time of MSS is 9.4 s for a high-resolution research tomograph (HRRT) system. The performance of the proposed MSS is validated through actual experiments using an HRRT.

  18. 3D hybrid-porous carbon derived from carbonization of metal organic frameworks for high performance supercapacitors

    NASA Astrophysics Data System (ADS)

    Bao, Weizhai; Mondal, Anjon Kumar; Xu, Jing; Wang, Chengyin; Su, Dawei; Wang, Guoxiu

    2016-09-01

    We report a rational design and synthesis of 3D hybrid-porous carbon with a hierarchical pore architecture for high performance supercapacitors. It contains micropores (<2 nm diameter) and mesopores (2-4 nm), derived from carbonization of unique porous metal organic frameworks (MOFs). Owning to the synergistic effect of micropores and mesopores, the hybrid-porous carbon has exceptionally high ion-accessible surface area and low ion diffusion resistance, which is desired for supercapacitor applications. When applied as electrode materials in supercapacitors, 3D hybrid-porous carbon demonstrates a specific capacitance of 332 F g-1 at a constant charge/discharge current of 500 mA g-1. The supercapacitors can endure more than 10,000 cycles without degradation of capacitance.

  19. Mixed-hybrid and vertex-discontinuous-Galerkin finite element modeling of multiphase compositional flow on 3D unstructured grids

    NASA Astrophysics Data System (ADS)

    Moortgat, Joachim; Firoozabadi, Abbas

    2016-06-01

    Problems of interest in hydrogeology and hydrocarbon resources involve complex heterogeneous geological formations. Such domains are most accurately represented in reservoir simulations by unstructured computational grids. Finite element methods accurately describe flow on unstructured meshes with complex geometries, and their flexible formulation allows implementation on different grid types. In this work, we consider for the first time the challenging problem of fully compositional three-phase flow in 3D unstructured grids, discretized by any combination of tetrahedra, prisms, and hexahedra. We employ a mass conserving mixed hybrid finite element (MHFE) method to solve for the pressure and flux fields. The transport equations are approximated with a higher-order vertex-based discontinuous Galerkin (DG) discretization. We show that this approach outperforms a face-based implementation of the same polynomial order. These methods are well suited for heterogeneous and fractured reservoirs, because they provide globally continuous pressure and flux fields, while allowing for sharp discontinuities in compositions and saturations. The higher-order accuracy improves the modeling of strongly non-linear flow, such as gravitational and viscous fingering. We review the literature on unstructured reservoir simulation models, and present many examples that consider gravity depletion, water flooding, and gas injection in oil saturated reservoirs. We study convergence rates, mesh sensitivity, and demonstrate the wide applicability of our chosen finite element methods for challenging multiphase flow problems in geometrically complex subsurface media.

  20. Capabilities of a Global 3D MHD Model for Monitoring Extremely Fast CMEs

    NASA Astrophysics Data System (ADS)

    Wu, C. C.; Plunkett, S. P.; Liou, K.; Socker, D. G.; Wu, S. T.; Wang, Y. M.

    2015-12-01

    Since the start of the space era, spacecraft have recorded many extremely fast coronal mass ejections (CMEs) which have resulted in severe geomagnetic storms. Accurate and timely forecasting of the space weather effects of these events is important for protecting expensive space assets and astronauts and avoiding communications interruptions. Here, we will introduce a newly developed global, three-dimensional (3D) magnetohydrodynamic (MHD) model (G3DMHD). The model takes the solar magnetic field maps at 2.5 solar radii (Rs) and intepolates the solar wind plasma and field out to 18 Rs using the algorithm of Wang and Sheeley (1990, JGR). The output is used as the inner boundary condition for a 3D MHD model. The G3DMHD model is capable of simulating (i) extremely fast CME events with propagation speeds faster than 2500 km/s; and (ii) multiple CME events in sequence or simultaneously. We will demonstrate the simulation results (and comparison with in-situ observation) for the fastest CME in record on 23 July 2012, the shortest transit time in March 1976, and the well-known historic Carrington 1859 event.

  1. 3D global estimation and augmented reality visualization of intra-operative X-ray dose.

    PubMed

    Rodas, Nicolas Loy; Padoy, Nicolas

    2014-01-01

    The growing use of image-guided minimally-invasive surgical procedures is confronting clinicians and surgical staff with new radiation exposure risks from X-ray imaging devices. The accurate estimation of intra-operative radiation exposure can increase staff awareness of radiation exposure risks and enable the implementation of well-adapted safety measures. The current surgical practice of wearing a single dosimeter at chest level to measure radiation exposure does not provide a sufficiently accurate estimation of radiation absorption throughout the body. In this paper, we propose an approach that combines data from wireless dosimeters with the simulation of radiation propagation in order to provide a global radiation risk map in the area near the X-ray device. We use a multi-camera RGBD system to obtain a 3D point cloud reconstruction of the room. The positions of the table, C-arm and clinician are then used 1) to simulate the propagation of radiation in a real-world setup and 2) to overlay the resulting 3D risk-map onto the scene in an augmented reality manner. By using real-time wireless dosimeters in our system, we can both calibrate the simulation and validate its accuracy at specific locations in real-time. We demonstrate our system in an operating room equipped with a robotised X-ray imaging device and validate the radiation simulation on several X-ray acquisition setups. PMID:25333145

  2. 3D Tissue Culturing: Tissue in Cube: In Vitro 3D Culturing Platform with Hybrid Gel Cubes for Multidirectional Observations (Adv. Healthcare Mater. 13/2016).

    PubMed

    Hagiwara, Masaya; Kawahara, Tomohiro; Nobata, Rina

    2016-07-01

    An in vitro 3D culturing platform enabling multidirectional observations of 3D biosamples is presented by M. Hagiwara and co-workers on page 1566. 3D recognition of a sample structure can be achieved by facilitating multi-directional views using a standard microscope without a laser system. The cubic platform has the potential to promote 3D culture studies, offering easy handling and compatibility with commercial culture plates at a low price tag. PMID:27384934

  3. 3D Tissue Culturing: Tissue in Cube: In Vitro 3D Culturing Platform with Hybrid Gel Cubes for Multidirectional Observations (Adv. Healthcare Mater. 13/2016).

    PubMed

    Hagiwara, Masaya; Kawahara, Tomohiro; Nobata, Rina

    2016-07-01

    An in vitro 3D culturing platform enabling multidirectional observations of 3D biosamples is presented by M. Hagiwara and co-workers on page 1566. 3D recognition of a sample structure can be achieved by facilitating multi-directional views using a standard microscope without a laser system. The cubic platform has the potential to promote 3D culture studies, offering easy handling and compatibility with commercial culture plates at a low price tag.

  4. Fabrication of chitosan-silver nanoparticle hybrid 3D porous structure as a SERS substrate for biomedical applications

    NASA Astrophysics Data System (ADS)

    Jung, Gyeong-Bok; Kim, Ji-Hye; Burm, Jin Sik; Park, Hun-Kuk

    2013-05-01

    We propose a simple, low-cost, large-area, and functional surface enhanced Raman scattering (SERS) substrate for biomedical applications. The SERS substrate with chitosan-silver nanoparticles (chitosan-Ag NPs) hybrid 3D porous structure was fabricated simply by a one-step method. The chitosan was used as a template for the Ag NPs deposition. SERS enhancement by the chitosan-Ag NPs substrate was experimentally verified using rhodamine B as an analyte. Thiolated single stranded DNA was also measured for atopic dermatitis genetic markers (chemokines CCL17) at a low concentration of 5 pM. We successfully designed a novel SERS substrate with silver nanoparticle hybridized 3D porous chitosan that has the potential to become a highly sensitive and selective tool for biomedical applications.

  5. Robust 2D/3D registration for fast-flexion motion of the knee joint using hybrid optimization.

    PubMed

    Ohnishi, Takashi; Suzuki, Masahiko; Kobayashi, Tatsuya; Naomoto, Shinji; Sukegawa, Tomoyuki; Nawata, Atsushi; Haneishi, Hideaki

    2013-01-01

    Previously, we proposed a 2D/3D registration method that uses Powell's algorithm to obtain 3D motion of a knee joint by 3D computed-tomography and bi-plane fluoroscopic images. The 2D/3D registration is performed consecutively and automatically for each frame of the fluoroscopic images. This method starts from the optimum parameters of the previous frame for each frame except for the first one, and it searches for the next set of optimum parameters using Powell's algorithm. However, if the flexion motion of the knee joint is fast, it is likely that Powell's algorithm will provide a mismatch because the initial parameters are far from the correct ones. In this study, we applied a hybrid optimization algorithm (HPS) combining Powell's algorithm with the Nelder-Mead simplex (NM-simplex) algorithm to overcome this problem. The performance of the HPS was compared with the separate performances of Powell's algorithm and the NM-simplex algorithm, the Quasi-Newton algorithm and hybrid optimization algorithm with the Quasi-Newton and NM-simplex algorithms with five patient data sets in terms of the root-mean-square error (RMSE), target registration error (TRE), success rate, and processing time. The RMSE, TRE, and the success rate of the HPS were better than those of the other optimization algorithms, and the processing time was similar to that of Powell's algorithm alone.

  6. SALSA3D - A Global 3D P-Velocity Model of the Earth's Crust and Mantle for Improved Event Location

    NASA Astrophysics Data System (ADS)

    Ballard, S.; Begnaud, M. L.; Young, C. J.; Hipp, J. R.; Chang, M.; Encarnacao, A. V.; Rowe, C. A.; Phillips, W. S.; Steck, L.

    2010-12-01

    To test the hypothesis that high quality 3D Earth models will produce seismic event locations which are more accurate and more precise, we are developing a global 3D P wave velocity model of the Earth’s crust and mantle using seismic tomography. In this paper, we present the most recent version of our model, SALSA3D version 1.5, and demonstrate its ability to reduce mislocations for a large set of realizations derived from a carefully chosen set of globally-distributed ground truth events. Our model is derived from the latest version of the Ground Truth (GT) catalog of P and Pn travel time picks assembled by Los Alamos National Laboratory. To prevent over-weighting due to ray path redundancy and to reduce the computational burden, we cluster rays to produce representative rays. Reduction in the total number of ray paths is ~50%. The model is represented using the triangular tessellation system described by Ballard et al. (2009), which incorporates variable resolution in both the geographic and radial dimensions.. For our starting model, we use a simplified two layer crustal model derived from the Crust 2.0 model over a uniform AK135 mantle. Sufficient damping is used to reduce velocity adjustments so that ray path changes between iterations are small. We obtain proper model smoothness by using progressive grid refinement, refining the grid only around areas with significant velocity changes from the starting model. At each grid refinement level except the last one we limit the number of iterations to prevent convergence thereby preserving aspects of broad features resolved at coarser resolutions. Our approach produces a smooth, multi-resolution model with node density appropriate to both ray coverage and the velocity gradients required by the data. This scheme is computationally expensive, so we use a distributed computing framework based on the Java Parallel Processing Framework, providing us with ~400 processors. Resolution of our model is assessed using a

  7. A Hybrid Antenna Array Design for 3-D Direction of Arrival Estimation

    PubMed Central

    Saqib, Najam-Us; Khan, Imdad

    2015-01-01

    A 3-D beam scanning antenna array design is proposed that gives a whole 3-D spherical coverage and also suitable for various radar and body-worn devices in the Body Area Networks applications. The Array Factor (AF) of the proposed antenna is derived and its various parameters like directivity, Half Power Beam Width (HPBW) and Side Lobe Level (SLL) are calculated by varying the size of the proposed antenna array. Simulations were carried out in MATLAB 2012b. The radiators are considered isotropic and hence mutual coupling effects are ignored. The proposed array shows a considerable improvement against the existing cylindrical and coaxial cylindrical arrays in terms of 3-D scanning, size, directivity, HPBW and SLL. PMID:25790103

  8. A hybrid antenna array design for 3-d direction of arrival estimation.

    PubMed

    Saqib, Najam-Us; Khan, Imdad

    2015-01-01

    A 3-D beam scanning antenna array design is proposed that gives a whole 3-D spherical coverage and also suitable for various radar and body-worn devices in the Body Area Networks applications. The Array Factor (AF) of the proposed antenna is derived and its various parameters like directivity, Half Power Beam Width (HPBW) and Side Lobe Level (SLL) are calculated by varying the size of the proposed antenna array. Simulations were carried out in MATLAB 2012b. The radiators are considered isotropic and hence mutual coupling effects are ignored. The proposed array shows a considerable improvement against the existing cylindrical and coaxial cylindrical arrays in terms of 3-D scanning, size, directivity, HPBW and SLL.

  9. Strontium eluting graphene hybrid nanoparticles augment osteogenesis in a 3D tissue scaffold.

    PubMed

    Kumar, Sachin; Chatterjee, Kaushik

    2015-02-01

    The objective of this work was to prepare hybrid nanoparticles of graphene sheets decorated with strontium metallic nanoparticles and demonstrate their advantages in bone tissue engineering. Strontium-decorated reduced graphene oxide (RGO_Sr) hybrid nanoparticles were synthesized by the facile reduction of graphene oxide and strontium nitrate. X-ray diffraction, transmission electron microscopy, and atomic force microscopy revealed that the hybrid particles were composed of RGO sheets decorated with 200-300 nm metallic strontium particles. Thermal gravimetric analysis further confirmed the composition of the hybrid particles as 22 wt% of strontium. Macroporous tissue scaffolds were prepared by incorporating RGO_Sr particles in poly(ε-caprolactone) (PCL). The PCL/RGO_Sr scaffolds were found to elute strontium ions in aqueous medium. Osteoblast proliferation and differentiation was significantly higher in the PCL scaffolds containing the RGO_Sr particles in contrast to neat PCL and PCL/RGO scaffolds. The increased biological activity can be attributed to the release of strontium ions from the hybrid nanoparticles. This study demonstrates that composites prepared using hybrid nanoparticles that elute strontium ions can be used to prepare multifunctional scaffolds with good mechanical and osteoinductive properties. These findings have important implications for designing the next generation of biomaterials for use in tissue regeneration. PMID:25553731

  10. Strontium eluting graphene hybrid nanoparticles augment osteogenesis in a 3D tissue scaffold.

    PubMed

    Kumar, Sachin; Chatterjee, Kaushik

    2015-02-01

    The objective of this work was to prepare hybrid nanoparticles of graphene sheets decorated with strontium metallic nanoparticles and demonstrate their advantages in bone tissue engineering. Strontium-decorated reduced graphene oxide (RGO_Sr) hybrid nanoparticles were synthesized by the facile reduction of graphene oxide and strontium nitrate. X-ray diffraction, transmission electron microscopy, and atomic force microscopy revealed that the hybrid particles were composed of RGO sheets decorated with 200-300 nm metallic strontium particles. Thermal gravimetric analysis further confirmed the composition of the hybrid particles as 22 wt% of strontium. Macroporous tissue scaffolds were prepared by incorporating RGO_Sr particles in poly(ε-caprolactone) (PCL). The PCL/RGO_Sr scaffolds were found to elute strontium ions in aqueous medium. Osteoblast proliferation and differentiation was significantly higher in the PCL scaffolds containing the RGO_Sr particles in contrast to neat PCL and PCL/RGO scaffolds. The increased biological activity can be attributed to the release of strontium ions from the hybrid nanoparticles. This study demonstrates that composites prepared using hybrid nanoparticles that elute strontium ions can be used to prepare multifunctional scaffolds with good mechanical and osteoinductive properties. These findings have important implications for designing the next generation of biomaterials for use in tissue regeneration.

  11. Trapping solids at the inner edge of the dead zone: 3-D global MHD simulations

    NASA Astrophysics Data System (ADS)

    Dzyurkevich, N.; Flock, M.; Turner, N. J.; Klahr, H.; Henning, Th.

    2010-06-01

    Context. The poorly-ionized interior of the protoplanetary disk or “dead zone” is the location where dust coagulation processes may be most efficient. However even here, planetesimal formation may be limited by the loss of solid material through radial drift, and by collisional fragmentation of the particles. Both depend on the turbulent properties of the gas. Aims: Our aim here is to investigate the possibility that solid particles are trapped at local pressure maxima in the dynamically evolving disk. We perform the first 3-D global non-ideal magnetohydrodynamical (MHD) calculations of a section of the disk treating the turbulence driven by the magneto-rotational instability (MRI). Methods: We use the ZeusMP code with a fixed Ohmic resistivity distribution. The domain contains an inner MRI-active region near the young star and an outer midplane dead zone, with the transition between the two modeled by a sharp increase in the magnetic diffusivity. Results: The azimuthal magnetic fields generated in the active zone oscillate over time, changing sign about every 150 years. We thus observe the radial structure of the “butterfly pattern” seen previously in local shearing-box simulations. The mean magnetic field diffuses from the active zone into the dead zone, where the Reynolds stress nevertheless dominates, giving a residual α between 10-4 and 10-3. The greater total accretion stress in the active zone leads to a net reduction in the surface density, so that after 800 years an approximate steady state is reached in which a local radial maximum in the midplane pressure lies near the transition radius. We also observe the formation of density ridges within the active zone. Conclusions: The dead zone in our models possesses a mean magnetic field, significant Reynolds stresses and a steady local pressure maximum at the inner edge, where the outward migration of planetary embryos and the efficient trapping of solid material are possible.

  12. 3D printing of high-resolution PLA-based structures by hybrid electrohydrodynamic and fused deposition modeling techniques

    NASA Astrophysics Data System (ADS)

    Zhang, Bin; Seong, Baekhoon; Nguyen, VuDat; Byun, Doyoung

    2016-02-01

    Recently, the three-dimensional (3D) printing technique has received much attention for shape forming and manufacturing. The fused deposition modeling (FDM) printer is one of the various 3D printers available and has become widely used due to its simplicity, low-cost, and easy operation. However, the FDM technique has a limitation whereby its patterning resolution is too low at around 200 μm. In this paper, we first present a hybrid mechanism of electrohydrodynamic jet printing with the FDM technique, which we name E-FDM. We then develop a novel high-resolution 3D printer based on the E-FDM process. To determine the optimal condition for structuring, we also investigated the effect of several printing parameters, such as temperature, applied voltage, working height, printing speed, flow-rate, and acceleration on the patterning results. This method was capable of fabricating both high resolution 2D and 3D structures with the use of polylactic acid (PLA). PLA has been used to fabricate scaffold structures for tissue engineering, which has different hierarchical structure sizes. The fabrication speed was up to 40 mm/s and the pattern resolution could be improved to 10 μm.

  13. A hybrid experimental-numerical technique for determining 3D velocity fields from planar 2D PIV data

    NASA Astrophysics Data System (ADS)

    Eden, A.; Sigurdson, M.; Mezić, I.; Meinhart, C. D.

    2016-09-01

    Knowledge of 3D, three component velocity fields is central to the understanding and development of effective microfluidic devices for lab-on-chip mixing applications. In this paper we present a hybrid experimental-numerical method for the generation of 3D flow information from 2D particle image velocimetry (PIV) experimental data and finite element simulations of an alternating current electrothermal (ACET) micromixer. A numerical least-squares optimization algorithm is applied to a theory-based 3D multiphysics simulation in conjunction with 2D PIV data to generate an improved estimation of the steady state velocity field. This 3D velocity field can be used to assess mixing phenomena more accurately than would be possible through simulation alone. Our technique can also be used to estimate uncertain quantities in experimental situations by fitting the gathered field data to a simulated physical model. The optimization algorithm reduced the root-mean-squared difference between the experimental and simulated velocity fields in the target region by more than a factor of 4, resulting in an average error less than 12% of the average velocity magnitude.

  14. Ship-in-a-bottle integration by hybrid femtosecond laser technology for fabrication of true 3D biochips

    NASA Astrophysics Data System (ADS)

    Sima, Felix; Wu, Dong; Xu, Jian; Midorikawa, Katsumi; Sugioka, Koji

    2015-03-01

    We propose herein the "ship-in-a-bottle" integration of three-dimensional (3D) polymeric sinusoidal ridges inside photosensitive glass microfluidic channel by a hybrid subtractive - additive femtosecond laser processing method. It consists of Femtosecond Laser Assisted Wet Etching (FLAE) of a photosensitive Foturan glass followed by Two-Photon Polymerization (TPP) of a SU-8 negative epoxy-resin. Both subtractive and additive processes are carried out using the same set-up with the change of laser focusing objective only. A 522 nm wavelength of the second harmonic generation from an amplified femtosecond Yb-fiber laser (FCPA µJewel D-400, IMRA America, 1045 nm; pulse width 360 fs, repetition rate 200 kHz) was employed for irradiation. The new method allows lowering the size limit of 3D objects created inside channels to smaller details down to the dimensions of a cell, and improve the structure stability. Sinusoidal periodic patterns and ridges are of great use as base scaffolds for building up new structures on their top or for modulating cell migration, guidance and orientation while created interspaces can be exploited for microfluidic applications. The glass microchannel offers robustness and appropriate dynamic flow conditions for cellular studies while the integrated patterns are reducing the size of structure to the level of cells responsiveness. Taking advantage of the ability to directly fabricate 3D complex shapes, both glass channels and polymeric integrated patterns enable us to 3D spatially design biochips for specific applications.

  15. The anthropogenic influence on Iron deposition over the oceans: a 3-D global modeling

    NASA Astrophysics Data System (ADS)

    Myriokefalitakis, Stelios; Mihalopoulos, Nikos; Baker, Alex; Kanakidou, Maria

    2014-05-01

    Iron (Fe) deposition over oceans is directly linked to the marine biological productivity and consequently to atmospheric CO2 concentrations. Experimental and modeling results support that both inorganic (sulphate, ammonium and nitrate) and organic (e.g. oxalate) ligands can increase the Fe mobilization. Mineral dust deposition is considered as the most important supply of bioavailable Fe in the oceans. Although, due to the low soil soluble iron fractions, atmospheric processes which are also related to anthropogenic emissions, can convert iron to more soluble forms in the atmosphere. Recent studies also support that anthropogenic emissions of Fe from combustion sources also significantly contribute to the dissolved Fe atmospheric pool. The evaluation of the impact of humans on atmospheric soluble or bioavailable Fe deposition remains challenging, since Fe mobilization due to changes in anthropogenic emissions is largely uncertain. In the present study, the global atmospheric Fe cycle is parameterized in the 3-D chemical transport global model TM4-ECPL and the model is used to calculate the Fe deposition over the oceans. The model considers explicitly organic, sulfur and nitrogen gas-phase chemistry, aqueous-phase organic chemistry, including oxalate and all major aerosol constituents. TM4-ECPL simulates the organic and inorganic ligand-promoted mineral Fe dissolution and also aqueous-phase photochemical reactions between different forms of Fe (III/II). Primary emissions of Fe associated with dust and soluble Fe from combustion processes as well as atmospheric processing of the emitted Fe is taken into account in the model Sensitivity simulations are performed to study the impact of anthropogenic emissions on Fe deposition. For this preindustrial, present and future emission scenarios are used in the model in order to examine the response of chemical composition of iron-containing aerosols to environmental changes. The release of soluble iron associated with

  16. Uncertainty analysis in 3D global models: Aerosol representation in MOZART-4

    NASA Astrophysics Data System (ADS)

    Gasore, J.; Prinn, R. G.

    2012-12-01

    The Probabilistic Collocation Method (PCM) has been proven to be an efficient general method of uncertainty analysis in atmospheric models (Tatang et al 1997, Cohen&Prinn 2011). However, its application has been mainly limited to urban- and regional-scale models and chemical source-sink models, because of the drastic increase in computational cost when the dimension of uncertain parameters increases. Moreover, the high-dimensional output of global models has to be reduced to allow a computationally reasonable number of polynomials to be generated. This dimensional reduction has been mainly achieved by grouping the model grids into a few regions based on prior knowledge and expectations; urban versus rural for instance. As the model output is used to estimate the coefficients of the polynomial chaos expansion (PCE), the arbitrariness in the regional aggregation can generate problems in estimating uncertainties. To address these issues in a complex model, we apply the probabilistic collocation method of uncertainty analysis to the aerosol representation in MOZART-4, which is a 3D global chemical transport model (Emmons et al., 2010). Thereafter, we deterministically delineate the model output surface into regions of homogeneous response using the method of Principal Component Analysis. This allows the quantification of the uncertainty associated with the dimensional reduction. Because only a bulk mass is calculated online in Mozart-4, a lognormal number distribution is assumed with a priori fixed scale and location parameters, to calculate the surface area for heterogeneous reactions involving tropospheric oxidants. We have applied the PCM to the six parameters of the lognormal number distributions of Black Carbon, Organic Carbon and Sulfate. We have carried out a Monte-Carlo sampling from the probability density functions of the six uncertain parameters, using the reduced PCE model. The global mean concentration of major tropospheric oxidants did not show a

  17. Novel fabrication technique of hybrid structure lens array for 3D images

    NASA Astrophysics Data System (ADS)

    Lee, Junsik; Kim, Junoh; Kim, Cheoljoong; Shin, Dooseub; Koo, Gyohyun; Won, Yong Hyub

    2016-03-01

    Tunable liquid lens arrays can produce three dimensional images by using electrowetting principle that alters surface tensions by applying voltage. This method has advantages of fast response time and low power consumption. However, it is challenging to fabricate a high fill factor liquid lens array and operate three dimensional images which demand high diopter. This study describes a hybrid structure lens array which has not only a liquid lens array but a solid lens array. A concave-shape lens array is unavoidable when using only the liquid lens array and some voltages are needed to make the lens flat. By placing the solid lens array on the liquid lens array, initial diopter can be positive. To fabricate the hybrid structure lens array, a conventional lithographic process in semiconductor manufacturing is needed. A negative photoresist SU-8 was used as chamber master molds. PDMS and UV adhesive replica molding are done sequentially. Two immiscible liquids, DI water and dodecane, are injected in the fabricated chamber, followed by sealing. The fabricated structure has a 20 by 20 pattern of cylindrical shaped circle array and the aperture size of each lens is 1mm. The thickness of the overall hybrid structure is about 2.8mm. Hybrid structure lens array has many advantages. Solid lens array has almost 100% fill factor and allow high efficiency. Diopter can be increased by more than 200 and negative diopter can be shifted to the positive region. This experiment showed several properties of the hybrid structure and demonstrated its superiority.

  18. Gas phase synthesis and field emission properties of 3D aligned double walled carbon nanotube/anatase hybrid architectures.

    PubMed

    Joshi, Ravi K; Engstler, Jörg; Navitski, Aliaksandr; Sakharuk, Vitali; Müller, Günter; Schneider, Jörg J

    2011-08-01

    A 3D hybrid architecture composed of macroscopic, vertically aligned CNT blocks which are formed via a metal catalyzed CVD process followed by deposition of TiO(2) on the CNT side walls in nanocrystalline or amorphous form is presented. The morphology of the deposited TiO(2) can be tailored by the deposition method employed. Depositing TiO(2) from the gas phase by employing the organometallic precursor Ti[OCH(CH(3))(2)](4) leads to formation of nanocrystalline anatase or rutile particles with a dense coverage on the surface and within the 3D CNT scaffold. Phase pure TiO(2) (anatase) is formed between 500 and 700 °C, while higher temperatures resulted in rutile modification of TiO(2). Below 500 °C, TiO(2) forms an amorphous oxide layer. At higher temperatures such initially formed TiO(2) layers segregate into particles which tend to crystallize. In contrast, when generating TiO(2) by oxidation of Ti metal which is deposited by vaporization onto the 3D CNT block array, and subsequently oxidized in air or controlled O(2) atmosphere this leads to a porous layer with a particular nanostructure on top of the CNT blocks. First studies of the fabrication and field emission of the new 3D CNT/TiO(2) hybrid cathodes display good and stable FE characteristics with onset fields for current density of 1 μA cm(-2) of 1.7 to 1.9 V μm(-1), while the average field enhancement factor is in the range between 2000 and 2500 depending on the O(2) base pressure during the measurements.

  19. Growth and Transfer of Seamless 3D Graphene-Nanotube Hybrids.

    PubMed

    Kim, Nam Dong; Li, Yilun; Wang, Gunuk; Fan, Xiujun; Jiang, Jinlong; Li, Lei; Ji, Yongsung; Ruan, Gedeng; Hauge, Robert H; Tour, James M

    2016-02-10

    Seamlessly connected graphene and carbon nanotube hybrids (GCNTs) have great potential as carbon platform structures in electronics due to their high conductivity and high surface area. Here, we introduce a facile method for making patterned GCNTs and their intact transfer onto other substrates. The mechanism for selective growth of vertically aligned CNTs (VA-CNTs) on the patterned graphene is discussed. The complete transfer of the GCNT pattern onto other substrates is possible because of the mechanical strength of the GCNT hybrids. Electrical conductivity measurements of the transferred GCNT structures show Ohmic contact through the VA-CNTs to graphene--evidence of its integrity after the transfer process.

  20. Global Effects of the Interplanetary Shock Propagation through the Earth's Inner Magnetosphere: 3D Hybrid Kinetic ModelingA.S. Lipatov {1}, D.G. Sibeck {2}{1} GPHI UMBC/NASA GSFC, Greenbelt, MD 20771, USA {2} NASA GSFC, Greenbelt, MD 20771, USA

    NASA Astrophysics Data System (ADS)

    Lipatov, A. S.; Sibeck, D. G.

    2015-12-01

    We use a new hybrid kinetic model to simulate the response of ring current, outer radiation belt, and plasmasphere particle populations to impulsive interplanetary shocks. Since particle distributions attending the interplanetary shock waves and in the ring current and radiation belts are non-Maxwellian, wave-particle interactions play a crucial role in energy transport within the inner magnetosphere. Finite gyroradius effects become important in mass loading the shock waves with the background plasma in the presence of higher energy ring current and radiation belt ions and electrons. Initial results show that the shock causes strong deformations in the global structure of the ring current, radiation belt, and plasmasphere. The ion velocity distribution functions at the shock front, in the ring current, and in the radiation belt help us to determine energy transport through the Earth's inner magnetosphere. We compare our predictions with THEMIS and Van Allen Probes spacecraft observations.

  1. A global model simulation for 3-D radiative transfer impact on surface hydrology over Sierra Nevada and Rocky Mountains

    DOE PAGES

    Lee, W. -L.; Gu, Y.; Liou, K. N.; Leung, L. R.; Hsu, H. -H.

    2014-12-15

    We investigate 3-D mountain effects on solar flux distributions and their impact on surface hydrology over the Western United States, specifically the Rocky Mountains and Sierra Nevada using CCSM4 (CAM4/CLM4) global model with a 0.23° × 0.31° resolution for simulations over 6 years. In 3-D radiative transfer parameterization, we have updated surface topography data from a resolution of 1 km to 90 m to improve parameterization accuracy. In addition, we have also modified the upward-flux deviation [3-D - PP (plane-parallel)] adjustment to ensure that energy balance at the surface is conserved in global climate simulations based on 3-D radiation parameterization.more » We show that deviations of the net surface fluxes are not only affected by 3-D mountains, but also influenced by feedbacks of cloud and snow in association with the long-term simulations. Deviations in sensible heat and surface temperature generally follow the patterns of net surface solar flux. The monthly snow water equivalent (SWE) deviations show an increase in lower elevations due to reduced snowmelt, leading to a reduction in cumulative runoff. Over higher elevation areas, negative SWE deviations are found because of increased solar radiation available at the surface. Simulated precipitation increases for lower elevations, while decreases for higher elevations with a minimum in April. Liquid runoff significantly decreases in higher elevations after April due to reduced SWE and precipitation.« less

  2. Hybrid nickel manganese oxide nanosheet-3D metallic dendrite percolation network electrodes for high-rate electrochemical energy storage

    NASA Astrophysics Data System (ADS)

    Nguyen, Tuyen; Eugénio, Sónia; Boudard, Michel; Rapenne, Laetitia; Carmezim, M. João; Silva, Teresa M.; Montemor, M. Fátima

    2015-07-01

    This work reports the fabrication, by electrodeposition and post-thermal annealing, of hybrid electrodes for high rate electrochemical energy storage composed of nickel manganese oxide (Ni0.86Mn0.14O) nanosheets over 3D open porous dendritic NiCu foams. The hybrid electrodes are made of two different percolation networks of nanosheets and dendrites, and exhibit a specific capacitance value of 848 F g-1 at 1 A g-1. The electrochemical tests revealed that the electrodes display an excellent rate capability, characterized by capacitance retention of approximately 83% when the applied current density increases from 1 A g-1 to 20 A g-1. The electrodes also evidenced high charge-discharge cycling stability, which attained 103% after 1000 cycles.

  3. 3D Global Coronal Density Structure and Associated Magnetic Field near Solar Maximum

    NASA Astrophysics Data System (ADS)

    Kramar, Maxim; Airapetian, Vladimir; Lin, Haosheng

    2016-08-01

    Measurement of the coronal magnetic field is a crucial ingredient in understanding the nature of solar coronal dynamic phenomena at all scales. We employ STEREO/COR1 data obtained near maximum of solar activity in December 2012 (Carrington rotation, CR 2131) to retrieve and analyze the three-dimensional (3D) coronal electron density in the range of heights from 1.5 to 4 R_⊙ using a tomography method and qualitatively deduce structures of the coronal magnetic field. The 3D electron density analysis is complemented by the 3D STEREO/EUVI emissivity in 195 Å band obtained by tomography for the same CR period. We find that the magnetic field configuration during CR 2131 has a tendency to become radially open at heliocentric distances below ˜ 2.5 R_⊙. We compared the reconstructed 3D coronal structures over the CR near the solar maximum to the one at deep solar minimum. Results of our 3D density reconstruction will help to constrain solar coronal field models and test the accuracy of the magnetic field approximations for coronal modeling.

  4. A global 3-D CTM evaluation of black carbon in the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    He, C.; Li, Q. B.; Liou, K. N.; Zhang, J.; Qi, L.; Mao, Y.; Gao, M.; Lu, Z.; Streets, D. G.; Zhang, Q.; Sarin, M. M.; Ram, K.

    2014-07-01

    We systematically evaluate the black carbon (BC) simulations for 2006 over the Tibetan Plateau by a global 3-D chemical transport model (CTM) (GEOS-Chem) driven by GEOS-5 assimilated meteorological fields, using in situ measurements of BC in surface air, BC in snow, and BC absorption aerosol optical depth (AAOD). Using improved anthropogenic BC emission inventories for Asia that account for rapid technology renewal and energy consumption growth (Zhang et al., 2009; Lu et al., 2011) and improved global biomass burning emission inventories that account for small fires (van der Werf et al., 2010; Randerson et al., 2012), we find that model results of both BC in surface air and in snow are statistically in good agreement with observations (biases < 15%) away from urban centers. Model results capture the seasonal variations of the surface BC concentrations at rural sites in the Indo-Gangetic Plain, but the observed elevated values in winter are absent. Modeled surface-BC concentrations are within a factor of 2 of the observations at remote sites. Part of the discrepancy is explained by the deficiencies of the meteorological fields over the complex Tibetan terrain. We find that BC concentrations in snow computed from modeled BC deposition and GEOS-5 precipitation are spatiotemporally consistent with observations (r = 0.85). The computed BC concentrations in snow are a factor of 2-4 higher than the observations at several Himalayan sites because of excessive BC deposition. The BC concentrations in snow are biased low by a factor of 2 in the central plateau, which we attribute to the absence of snow aging in the CTM and strong local emissions unaccounted for in the emission inventories. Modeled BC AAOD is more than a factor of 2 lower than observations at most sites, particularly to the northwest of the plateau and along the southern slopes of the Himalayas in winter and spring, which is attributable in large part to underestimated emissions and the assumption of external

  5. Characterizing microscale aluminum composite layer properties on silicon solar cells with hybrid 3D scanning force measurements

    PubMed Central

    Bae, Sung-Kuk; Choi, Beomjoon; Chung, Haseung; Shin, Seungwon; Song, Hee-eun; Seo, Jung Hwan

    2016-01-01

    This article presents a novel technique to estimate the mechanical properties of the aluminum composite layer on silicon solar cells by using a hybrid 3-dimensional laser scanning force measurement (3-D LSFM) system. The 3-D LSFM system measures the material properties of sub-layers constituting a solar cell. This measurement is critical for realizing high-efficient ultra-thin solar cells. The screen-printed aluminum layer, which significantly affects the bowing phenomenon, is separated from the complete solar cell by removing the silicon (Si) layer with deep reactive ion etching. An elastic modulus of ~15.1 GPa and a yield strength of ~35.0 MPa for the aluminum (Al) composite layer were obtained by the 3-D LSFM system. In experiments performed for 6-inch Si solar cells, the bowing distances decreased from 12.02 to 1.18 mm while the Si layer thicknesses increased from 90 to 190 μm. These results are in excellent agreement with the theoretical predictions for ultra-thin Si thickness (90 μm) based on the obtained Al composite layer properties. PMID:26948248

  6. Electrochemically formed 3D hierarchical thin films of cobalt-manganese (Co-Mn) hexacyanoferrate hybrids for electrochemical applications

    NASA Astrophysics Data System (ADS)

    Alam Venugopal, Narendra Kumar; Joseph, James

    2016-02-01

    Here we report the feasibility of forming 3D nanostructured hexacyanoferates of Cobalt and Manganese (Co-MnHCF) on GC surface by a facile electrochemical method. This 3D architecture on glassy carbon electrode characterised systematically by voltammetry and other physical characterisation techniques like Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and Fourier transform Infrared spectroscopy (FTIR) etc,. Electrochemical Quartz crystal microbalance (EQCM) studies helped out to calculate the total mass change during Co-MnHCF formation. Electrochemical studies reveal that the formal redox potentials of both Co and MnHCF films remained close to that of newly formed Co-MnHCF hybrid films. These 3D modified films were successfully applied for two different electrochemical applications i) For pseudocapacitor studies in KNO3 medium ii) Investigated the electrocatalytic behaviour of redox film towards water oxidation reaction in alkaline medium. Electrochemical performances of newly formed Co-MnHCF are compared with their individual transition metal (Co, Mn) hexacyanoferrates. The resulting material shows a specific capacitance of 350 F g-1 through its fast reversible redox reaction of electrochemically formed Co-MnHCF modified film. Interestingly we showed the overpotential of 450 mV (from its thermodynamic voltage 1.2 V) to attain its optimum current density of 10 mA cm-2 for O2 evolution in alkaline medium.

  7. Characterizing microscale aluminum composite layer properties on silicon solar cells with hybrid 3D scanning force measurements

    NASA Astrophysics Data System (ADS)

    Bae, Sung-Kuk; Choi, Beomjoon; Chung, Haseung; Shin, Seungwon; Song, Hee-Eun; Seo, Jung Hwan

    2016-03-01

    This article presents a novel technique to estimate the mechanical properties of the aluminum composite layer on silicon solar cells by using a hybrid 3-dimensional laser scanning force measurement (3-D LSFM) system. The 3-D LSFM system measures the material properties of sub-layers constituting a solar cell. This measurement is critical for realizing high-efficient ultra-thin solar cells. The screen-printed aluminum layer, which significantly affects the bowing phenomenon, is separated from the complete solar cell by removing the silicon (Si) layer with deep reactive ion etching. An elastic modulus of ~15.1 GPa and a yield strength of ~35.0 MPa for the aluminum (Al) composite layer were obtained by the 3-D LSFM system. In experiments performed for 6-inch Si solar cells, the bowing distances decreased from 12.02 to 1.18 mm while the Si layer thicknesses increased from 90 to 190 μm. These results are in excellent agreement with the theoretical predictions for ultra-thin Si thickness (90 μm) based on the obtained Al composite layer properties.

  8. Characterizing microscale aluminum composite layer properties on silicon solar cells with hybrid 3D scanning force measurements.

    PubMed

    Bae, Sung-Kuk; Choi, Beomjoon; Chung, Haseung; Shin, Seungwon; Song, Hee-eun; Seo, Jung Hwan

    2016-01-01

    This article presents a novel technique to estimate the mechanical properties of the aluminum composite layer on silicon solar cells by using a hybrid 3-dimensional laser scanning force measurement (3-D LSFM) system. The 3-D LSFM system measures the material properties of sub-layers constituting a solar cell. This measurement is critical for realizing high-efficient ultra-thin solar cells. The screen-printed aluminum layer, which significantly affects the bowing phenomenon, is separated from the complete solar cell by removing the silicon (Si) layer with deep reactive ion etching. An elastic modulus of ~15.1 GPa and a yield strength of ~35.0 MPa for the aluminum (Al) composite layer were obtained by the 3-D LSFM system. In experiments performed for 6-inch Si solar cells, the bowing distances decreased from 12.02 to 1.18 mm while the Si layer thicknesses increased from 90 to 190 μm. These results are in excellent agreement with the theoretical predictions for ultra-thin Si thickness (90 μm) based on the obtained Al composite layer properties. PMID:26948248

  9. Characterizing microscale aluminum composite layer properties on silicon solar cells with hybrid 3D scanning force measurements.

    PubMed

    Bae, Sung-Kuk; Choi, Beomjoon; Chung, Haseung; Shin, Seungwon; Song, Hee-eun; Seo, Jung Hwan

    2016-03-07

    This article presents a novel technique to estimate the mechanical properties of the aluminum composite layer on silicon solar cells by using a hybrid 3-dimensional laser scanning force measurement (3-D LSFM) system. The 3-D LSFM system measures the material properties of sub-layers constituting a solar cell. This measurement is critical for realizing high-efficient ultra-thin solar cells. The screen-printed aluminum layer, which significantly affects the bowing phenomenon, is separated from the complete solar cell by removing the silicon (Si) layer with deep reactive ion etching. An elastic modulus of ~15.1 GPa and a yield strength of ~35.0 MPa for the aluminum (Al) composite layer were obtained by the 3-D LSFM system. In experiments performed for 6-inch Si solar cells, the bowing distances decreased from 12.02 to 1.18 mm while the Si layer thicknesses increased from 90 to 190 μm. These results are in excellent agreement with the theoretical predictions for ultra-thin Si thickness (90 μm) based on the obtained Al composite layer properties.

  10. Antigenic and 3D structural characterization of soluble X4 and hybrid X4-R5 HIV-1 Env trimers

    PubMed Central

    2014-01-01

    Background HIV-1 is decorated with trimeric glycoprotein spikes that enable infection by engaging CD4 and a chemokine coreceptor, either CCR5 or CXCR4. The variable loop 3 (V3) of the HIV-1 envelope protein (Env) is the main determinant for coreceptor usage. The predominant CCR5 using (R5) HIV-1 Env has been intensively studied in function and structure, whereas the trimeric architecture of the less frequent, but more cytopathic CXCR4 using (X4) HIV-1 Env is largely unknown, as are the consequences of sequence changes in and near V3 on antigenicity and trimeric Env structure. Results Soluble trimeric gp140 Env constructs were used as immunogenic mimics of the native spikes to analyze their antigenic properties in the context of their overall 3D structure. We generated soluble, uncleaved, gp140 trimers from a prototypic T-cell line-adapted (TCLA) X4 HIV-1 strain (NL4-3) and a hybrid (NL4-3/ADA), in which the V3 spanning region was substituted with that from the primary R5 isolate ADA. Compared to an ADA (R5) gp140, the NL4-3 (X4) construct revealed an overall higher antibody accessibility, which was most pronounced for the CD4 binding site (CD4bs), but also observed for mAbs against CD4 induced (CD4i) epitopes and gp41 mAbs. V3 mAbs showed significant binding differences to the three constructs, which were refined by SPR analysis. Of interest, the NL4-3/ADA construct with the hybrid NL4-3/ADA CD4bs showed impaired CD4 and CD4bs mAb reactivity despite the presence of the essential elements of the CD4bs epitope. We obtained 3D reconstructions of the NL4-3 and the NL4-3/ADA gp140 trimers via electron microscopy and single particle analysis, which indicates that both constructs inherit a propeller-like architecture. The first 3D reconstruction of an Env construct from an X4 TCLA HIV-1 strain reveals an open conformation, in contrast to recently published more closed structures from R5 Env. Exchanging the X4 V3 spanning region for that of R5 ADA did not alter the open

  11. Left-ventricle segmentation in real-time 3D echocardiography using a hybrid active shape model and optimal graph search approach

    NASA Astrophysics Data System (ADS)

    Zhang, Honghai; Abiose, Ademola K.; Campbell, Dwayne N.; Sonka, Milan; Martins, James B.; Wahle, Andreas

    2010-03-01

    Quantitative analysis of the left ventricular shape and motion patterns associated with left ventricular mechanical dyssynchrony (LVMD) is essential for diagnosis and treatment planning in congestive heart failure. Real-time 3D echocardiography (RT3DE) used for LVMD analysis is frequently limited by heavy speckle noise or partially incomplete data, thus a segmentation method utilizing learned global shape knowledge is beneficial. In this study, the endocardial surface of the left ventricle (LV) is segmented using a hybrid approach combining active shape model (ASM) with optimal graph search. The latter is used to achieve landmark refinement in the ASM framework. Optimal graph search translates the 3D segmentation into the detection of a minimum-cost closed set in a graph and can produce a globally optimal result. Various information-gradient, intensity distributions, and regional-property terms-are used to define the costs for the graph search. The developed method was tested on 44 RT3DE datasets acquired from 26 LVMD patients. The segmentation accuracy was assessed by surface positioning error and volume overlap measured for the whole LV as well as 16 standard LV regions. The segmentation produced very good results that were not achievable using ASM or graph search alone.

  12. Finite Gyroradius Effects in the Plasma Environment Near Titan: 3D Hybrid Modeling of the T5 Encounter

    NASA Astrophysics Data System (ADS)

    Simpson, D. G.; Lipatov, A. S.; Sittler, E. C.; Cooper, J. F.; Hartle, R. E.; Sarantos, M.

    2012-12-01

    In this report we discuss the results of a 3D hybrid modeling of the interaction between Saturn's magnetosphere and Titan's atmosphere/ionosphere for the T5 encounter. The T5 flyby is the only encounter when the two main ionizing sources of Titan's atmosphere, solar radiation and corotating plasma, align quasi-anti-parallel. The model is based on recent analysis of the Cassini Plasma Spectrometer (CAPS) and the Cassini Ion and Neutral Mass Spectrometer (INMS) measurements during the T5 flyby through Titan's ram-side and polar ionosphere [1,2]. Magnetic field data was used from the MAG instrument [3]. In our model the background ions (O+, H+), all pickup ions, and ionospheric ions are considered as a particles, whereas the electrons are described as a fluid (see e.g. [4]). Inhomogeneous photoionization (in the dayside ionosphere), electron-impact ionization, and charge exchange are included in our model. The temperature of the background electrons and pickup electrons was also incorporated into the generalized Ohm's law. We also take into account collisions between ions and neutrals. In our hybrid simulations we use Chamberlain profiles for the exosphere's components. The moon is considered as a weakly conducting body. The first results of our hybrid modeling show a strong asymmetry in the background (H+, O+) and pickup (H2+, N2+, CH4+) ion density profiles. Such strong asymmetry cannot be explained by a single-fluid multi-species 3D MHD model [5], which includes complex chemistry but does not produce finite gyroradius and kinetic effects. References [1] Sittler, et al., Energy Deposition Processes in Titan's Atmosphere and Its Induced Magnetosphere. In: Titan from Cassini-Huygens, Brown, R.H., Lebreton, J.P., Waite, J.H., Eds., Springer, (Dordrecht, Heidelberg, London, New York), pp. 393-455, 2010. [2] Agren, K., et al., On magnetosphere electron impact ionization and dynamics in Titan's ram-side and polar ionosphere -- a Cassini case study, Ann. Geophys., 25, 2359

  13. Development and testing of stable, invariant, isoparametric curvilinear 2- and 3-D hybrid-stress elements

    NASA Technical Reports Server (NTRS)

    Punch, E. F.; Atluri, S. N.

    1984-01-01

    Linear and quadratic Serendipity hybrid-stress elements are examined in respect of stability, coordinate invariance, and optimality. A formulation based upon symmetry group theory successfully addresses these issues in undistorted geometries and is fully detailed for plane elements. The resulting least-order stable invariant stress polynomials can be applied as astute approximations in distorted cases through a variety of tensor components and variational principles. A distortion sensitivity study for two- and three-dimensional elements provides favorable numerical comparisons with the assumed displacement method.

  14. Sulfur in the Early Martian Atmosphere Revisited: Experiments with a 3-D Global Climate Model

    NASA Astrophysics Data System (ADS)

    Kerber, L.; Forget, F.; Wordsworth, R.

    2013-09-01

    [8]. A successful working model for the early Martian atmosphere and hydrosphere must be able not only to produce conditions suitable for liquid water at the surface, but also to explain how the nature of this aqueous activity changed over time and eventually diminished. There are two major end-member hypotheses: first, that early Mars was wet and warm, with a sustained greenhouse that made it possible for liquid water to be stable on the surface for extended periods [e.g., 2, 12-14], and second, that early Mars was generally cold, and that most of the aqueous alteration took place underground [3,5] or during transient warm periods tied to impact cratering [15], or volcanism [16]. In both of these scenarios it is generally agreed that in order to make valley networks and sulfate deposits, a hydrological cycle is needed which is able to recycle water from the lowlands back to the highlands (i.e., the one-time emptying of a regional aquifer would not be sufficient to create the observed features) [4,17]. This would require some precipitation to fall on the southern highlands, either flowing overland or filtering into groundwater aquifers. In both cases, volcanic gases (especially SO2) have been suggested as a possible way of creating either a sustained or transient greenhouse. Several researchers have tested the addition of SO2 to climate models in order to assess whether it would provide an adequate amount of greenhouse warming to allow liquid water to flow across the surface [18-21], with differing results. Postawko and Kuhn [18] found a warming effect of 14 K in a 0.1 bar atmosphere with an SO2 abundance of 1000 ppm. Johnson et al. [20] used a 3-D global circulation model and found a warming of 15-25 K for 245 ppm of SO2 in a dry 0.5 bar atmosphere. Tian et al. [21] used a 1-D model to explore a wide range of SO2 mixing values and CO2 partial pressures, finding a warming of around ~25 K for 100 ppm in a 0.5 bar atmosphere with a fully saturated troposphere (~40 K

  15. Jovian Plasma Torus Interaction with Europa: 3D Hybrid Kinetic Simulation. First results

    NASA Technical Reports Server (NTRS)

    Lipatov, A. S.; Cooper, J. F.; Paterson, W. R.; Sittler, E. C.; Hartle, R. E.; Simpson, D. G.

    2010-01-01

    The hybrid kinetic model supports comprehensive simulation of the interaction between different spatial and energetic elements of the Europa-moon-magnetosphere system with respect to variable upstream magnetic field and flux or density distributions of plasma and energetic ions, electrons, and neutral atoms. This capability is critical for improving the interpretation of the existing Europa flyby measurements from the Galileo orbiter mission, and for planning flyby and orbital measurements, (including the surface and atmospheric compositions) for future missions. The simulations are based on recent models of the atmosphere of Europa (Cassidy etal.,2007;Shematovichetal.,2005). In contrast to previous approaches with MHD simulations, the hybrid model allows us to fully take into account the finite gyro radius effect and electron pressure, and to correctly estimate the ion velocity distribution and the fluxes along the magnetic field (assuming an initial Maxwellian velocity distribution for upstream background ions).Non-thermal distributions of upstream plasma will be addressed in future work. Photoionization,electron-impact ionization, charge exchange and collisions between the ions and neutrals are also included in our model. We consider two models for background plasma:(a) with O(++) ions; (b) with O(++) and S(++) ions. The majority of O2 atmosphere is thermal with an extended cold population (Cassidyetal.,2007). A few first simulations already include an induced magnetic dipole; however, several important effects of induced magnetic fields arising from oceanic shell conductivity will be addressed in later work.

  16. Robotic deposition and in vitro characterization of 3D gelatin-bioactive glass hybrid scaffolds for biomedical applications.

    PubMed

    Gao, Chunxia; Rahaman, Mohamed N; Gao, Qiang; Teramoto, Akira; Abe, Koji

    2013-07-01

    The development of inorganic-organic hybrid scaffolds with controllable degradation and bioactive properties is receiving considerable interest for bone and tissue regeneration. The objective of this study was to create hybrid scaffolds of gelatin and bioactive glass (BG) with a controlled, three-dimensional (3D) architecture by a combined sol-gel and robotic deposition (robocasting) method and evaluate their mechanical response, bioactivity, and response to cells in vitro. Inks for robotic deposition of the scaffolds were prepared by dissolving gelatin in a sol-gel precursor solution of the bioactive glass (70SiO2 -25CaO-5P2 O5 ; mol%) and aging the solution to form a gel with the requisite viscosity. After drying and crosslinking, the gelatin-BG scaffolds, with a grid-like architecture (filament diameter ∼350 µm; pore width ∼550 µm), showed an elasto-plastic response, with a compressive strength of 5.1 ± 0.6 MPa, in the range of values for human trabecular bone (2-12 MPa). When immersed in phosphate-buffered saline, the crosslinked scaffolds rapidly absorbed water (∼440% of its dry weight after 2 h) and showed an elastic response at deformations up to ∼60%. Immersion of the scaffolds in a simulated body fluid resulted in the formation of a hydroxyapatite-like surface layer within 5 days, indicating their bioactivity in vitro. The scaffolds supported the proliferation, alkaline phosphatase activity, and mineralization of osteogenic MC3T3-E1 cells in vitro, showing their biocompatibility. Altogether, the results indicate that these gelatin-BG hybrid scaffolds with a controlled, 3D architecture of inter-connected pores have potential for use as implants for bone regeneration.

  17. On the Global Regularity of a Helical-Decimated Version of the 3D Navier-Stokes Equations

    NASA Astrophysics Data System (ADS)

    Biferale, Luca; Titi, Edriss S.

    2013-06-01

    We study the global regularity, for all time and all initial data in H 1/2, of a recently introduced decimated version of the incompressible 3D Navier-Stokes (dNS) equations. The model is based on a projection of the dynamical evolution of Navier-Stokes (NS) equations into the subspace where helicity (the L 2-scalar product of velocity and vorticity) is sign-definite. The presence of a second (beside energy) sign-definite inviscid conserved quadratic quantity, which is equivalent to the H 1/2-Sobolev norm, allows us to demonstrate global existence and uniqueness, of space-periodic solutions, together with continuity with respect to the initial conditions, for this decimated 3D model. This is achieved thanks to the establishment of two new estimates, for this 3D model, which show that the H 1/2 and the time average of the square of the H 3/2 norms of the velocity field remain finite. Such two additional bounds are known, in the spirit of the work of H. Fujita and T. Kato (Arch. Ration. Mech. Anal. 16:269-315, 1964; Rend. Semin. Mat. Univ. Padova 32:243-260, 1962), to be sufficient for showing well-posedness for the 3D NS equations. Furthermore, they are directly linked to the helicity evolution for the dNS model, and therefore with a clear physical meaning and consequences.

  18. Jovian's plasma torus interaction with Europa. E12 pass: 3D hybrid kinetic modeling

    NASA Astrophysics Data System (ADS)

    Lipatov, A. S.; Cooper, J. F.; Sittler, E. C., Jr.; Paterson, W. R.; Hartle, R. E.

    2012-09-01

    The hybrid kinetic model supports comprehensive simulation of the interaction between different spatial and energetic elements of the Europa moonmagnetosphere system with respect to variable upstream magnetic field and flux or density distributions of plasma and energetic ions, electrons, and neutral atoms. This capability is critical for improving the interpretation of the existing Europa flybymeasurements from Galileo orbital mission and for planning flyby and orbital measurements for future missions. The simulations are based on recent models of the atmosphere of Europa [1, 2, 3]. The upstream parameters have been chosen from the plasma and magnetic field Galileo E12 observations, [4, 5]. In contrast to previous approaches with MHD simulations, the hybrid model allows us to fully take into account the finite gyroradius effect and electron pressure, and to correctly estimate the ions velocity distribution and the fluxes along themagnetic field [6]. Photoionization, electron-impact ionization and charge exchange are included in our model. The temperature of the background electrons and pickup electrons was also included into the generalized Ohm's law. The background plasma contains heavy (Mi/Qi = 16) and light (Mi/Qi = 1) ions [4]. In our modeling we take into account only O+ ions for magnetospheric plasma. The pickup ions were created from the atmosphere. The majority of O2 atmosphere is thermal with an extended non-thermal population [1]. The moon is modeled in this initial work as a weakly conducting body. The critical point of E12 pass is the extremely high density in upstream plasma, e.g. n0 = 70-571 cm-3 for ions with Mi/Qi ratio equals 16. This density results in to the superAlfvénic flow and it will change the physics of the interaction between Jovianmagnetosphere and Europa. The modeling show the formation of the Mach cone instead of the Alfv'en wing which was observed in hybrid modeling of E4 pass [6]. The modeling shows that the effective size of the

  19. A novel approach for global lung registration using 3D Markov-Gibbs appearance model.

    PubMed

    El-Baz, Ayman; Khalifa, Fahmi; Elnakib, Ahmed; Nitzken, Matthew; Soliman, Ahmed; McClure, Patrick; Abou El-Ghar, Mohamed; Gimel'farb, Georgy

    2012-01-01

    A new approach to align 3D CT data of a segmented lung object with a given prototype (reference lung object) using an affine transformation is proposed. Visual appearance of the lung from CT images, after equalizing their signals, is modeled with a new 3D Markov-Gibbs random field (MGRF) with pairwise interaction model. Similarity to the prototype is measured by a Gibbs energy of signal co-occurrences in a characteristic subset of voxel pairs derived automatically from the prototype. An object is aligned by an affine transformation maximizing the similarity by using an automatic initialization followed by a gradient search. Experiments confirm that our approach aligns complex objects better than popular conventional algorithms.

  20. Fabrication of 3D porous SF/β-TCP hybrid scaffolds for bone tissue reconstruction.

    PubMed

    Park, Hyun Jung; Min, Kyung Dan; Lee, Min Chae; Kim, Soo Hyeon; Lee, Ok Joo; Ju, Hyung Woo; Moon, Bo Mi; Lee, Jung Min; Park, Ye Ri; Kim, Dong Wook; Jeong, Ju Yeon; Park, Chan Hum

    2016-07-01

    Bio-ceramic is a biomaterial actively studied in the field of bone tissue engineering. But, only certain ceramic materials can resolve the corrosion problem and possess the biological affinity of conventional metal biomaterials. Therefore, the recent development of composites of hybrid composites and polymers has been widely studied. In this study, we aimed to select the best scaffold of silk fibroin and β-TCP hybrid for bone tissue engineering. We fabricated three groups of scaffold such as SF (silk fibroin scaffold), GS (silk fibroin/small granule size of β-TCP scaffold) and GM (silk fibroin/medium granule size of β-TCP scaffold), and we compared the characteristics of each group. During characterization of the scaffold, we used scanning electron microscopy (SEM) and a Fourier transform infrared spectroscopy (FTIR) for structural analysis. We compared the physiological properties of the scaffold regarding the swelling ratio, water uptake and porosity. To evaluate the mechanical properties, we examined the compressive strength of the scaffold. During in vitro testing, we evaluated cell attachment and cell proliferation (CCK-8). Finally, we confirmed in vivo new bone regeneration from the implanted scaffolds using histological staining and micro-CT. From these evaluations, the fabricated scaffold demonstrated high porosity with good inter-pore connectivity, showed good biocompatibility and high compressive strength and modulus. In particular, the present study indicates that the GM scaffold using β-TCP accelerates new bone regeneration of implanted scaffolds. Accordingly, our scaffold is expected to act a useful application in the field of bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1779-1787, 2016. PMID:26999521

  1. 1D-3D hybrid modeling-from multi-compartment models to full resolution models in space and time.

    PubMed

    Grein, Stephan; Stepniewski, Martin; Reiter, Sebastian; Knodel, Markus M; Queisser, Gillian

    2014-01-01

    Investigation of cellular and network dynamics in the brain by means of modeling and simulation has evolved into a highly interdisciplinary field, that uses sophisticated modeling and simulation approaches to understand distinct areas of brain function. Depending on the underlying complexity, these models vary in their level of detail, in order to cope with the attached computational cost. Hence for large network simulations, single neurons are typically reduced to time-dependent signal processors, dismissing the spatial aspect of each cell. For single cell or networks with relatively small numbers of neurons, general purpose simulators allow for space and time-dependent simulations of electrical signal processing, based on the cable equation theory. An emerging field in Computational Neuroscience encompasses a new level of detail by incorporating the full three-dimensional morphology of cells and organelles into three-dimensional, space and time-dependent, simulations. While every approach has its advantages and limitations, such as computational cost, integrated and methods-spanning simulation approaches, depending on the network size could establish new ways to investigate the brain. In this paper we present a hybrid simulation approach, that makes use of reduced 1D-models using e.g., the NEURON simulator-which couples to fully resolved models for simulating cellular and sub-cellular dynamics, including the detailed three-dimensional morphology of neurons and organelles. In order to couple 1D- and 3D-simulations, we present a geometry-, membrane potential- and intracellular concentration mapping framework, with which graph- based morphologies, e.g., in the swc- or hoc-format, are mapped to full surface and volume representations of the neuron and computational data from 1D-simulations can be used as boundary conditions for full 3D simulations and vice versa. Thus, established models and data, based on general purpose 1D-simulators, can be directly coupled to the

  2. 1D-3D hybrid modeling—from multi-compartment models to full resolution models in space and time

    PubMed Central

    Grein, Stephan; Stepniewski, Martin; Reiter, Sebastian; Knodel, Markus M.; Queisser, Gillian

    2014-01-01

    Investigation of cellular and network dynamics in the brain by means of modeling and simulation has evolved into a highly interdisciplinary field, that uses sophisticated modeling and simulation approaches to understand distinct areas of brain function. Depending on the underlying complexity, these models vary in their level of detail, in order to cope with the attached computational cost. Hence for large network simulations, single neurons are typically reduced to time-dependent signal processors, dismissing the spatial aspect of each cell. For single cell or networks with relatively small numbers of neurons, general purpose simulators allow for space and time-dependent simulations of electrical signal processing, based on the cable equation theory. An emerging field in Computational Neuroscience encompasses a new level of detail by incorporating the full three-dimensional morphology of cells and organelles into three-dimensional, space and time-dependent, simulations. While every approach has its advantages and limitations, such as computational cost, integrated and methods-spanning simulation approaches, depending on the network size could establish new ways to investigate the brain. In this paper we present a hybrid simulation approach, that makes use of reduced 1D-models using e.g., the NEURON simulator—which couples to fully resolved models for simulating cellular and sub-cellular dynamics, including the detailed three-dimensional morphology of neurons and organelles. In order to couple 1D- and 3D-simulations, we present a geometry-, membrane potential- and intracellular concentration mapping framework, with which graph- based morphologies, e.g., in the swc- or hoc-format, are mapped to full surface and volume representations of the neuron and computational data from 1D-simulations can be used as boundary conditions for full 3D simulations and vice versa. Thus, established models and data, based on general purpose 1D-simulators, can be directly coupled to

  3. 3D Bridged Carbon Nanoring/Graphene Hybrid Paper as a High-Performance Lateral Heat Spreader.

    PubMed

    Zhang, Jianwei; Shi, Gang; Jiang, Cai; Ju, Su; Jiang, Dazhi

    2015-12-01

    Graphene paper (GP) has attracted great attention as a heat dissipation material due to its unique thermal transfer property exceeding the limit of graphite. However, the relatively poor thermal transfer properties in the normal direction of GP restricts its wider applications in thermal management. In this work, a 3D bridged carbon nanoring (CNR)/graphene hybrid paper is constructed by the intercalation of polymer carbon source and metal catalyst particles, and the subsequent in situ growth of CNRs in the confined intergallery spaces between graphene sheets through thermal annealing. Further investigation demonstrates that the CNRs are covalently bonded to the graphene sheets and highly improve the thermal transport in the normal direction of the CNR/graphene hybrid paper. This full-carbon architecture shows excellent heat dissipation ability and is much more efficient in removing hot spots than the reduced GP without CNR bridges. This highly thermally conductive CNR/graphene hybrid paper can be easily integrated into next generation commercial high-power electronics and stretchable/foldable devices as high-performance lateral heat spreader materials. This full-carbon architecture also has a great potential in acting as electrodes in supercapacitors or hydrogen storage devices due to the high surface area. PMID:26476622

  4. A computationally efficient hybrid 2D/3D thin film dislocation model

    NASA Astrophysics Data System (ADS)

    Sarrafan, Siavash

    Substantial research has been devoted to attempting to understand how dislocation structures evolve and how they affect device properties. However, current dislocation simulation methods are only able to model highly idealized systems accurately. The three-dimensional discrete dislocation dynamics models, in particular, are too computationally intensive for modelling high dislocation densities and their resultant deformations that are observed in some real applications. In this thesis, we propose a novel method to exploit the quasi-two-dimensional nature of three-dimensional dislocation loops in a thin film to model their behaviors. For most film configurations, simulation performance can be greatly enhanced by implementing a hybrid two-dimensional/three-dimensional model without losing significant fidelity. In this technique, misfits stress fields are modeled by superposing multiple two-dimensional models. Threads are modeled with a more traditional three-dimensional implementation as they move through the misfit stress field. Using this innovative technique, much higher strains and/or dislocation densities could be studied.

  5. Piezoresistive Sensor with High Elasticity Based on 3D Hybrid Network of Sponge@CNTs@Ag NPs.

    PubMed

    Zhang, Hui; Liu, Nishuang; Shi, Yuling; Liu, Weijie; Yue, Yang; Wang, Siliang; Ma, Yanan; Wen, Li; Li, Luying; Long, Fei; Zou, Zhengguang; Gao, Yihua

    2016-08-31

    Pressure sensors with high elasticity are in great demand for the realization of intelligent sensing, but there is a need to develope a simple, inexpensive, and scalable method for the manufacture of the sensors. Here, we reported an efficient, simple, facile, and repeatable "dipping and coating" process to manufacture a piezoresistive sensor with high elasticity, based on homogeneous 3D hybrid network of carbon nanotubes@silver nanoparticles (CNTs@Ag NPs) anchored on a skeleton sponge. Highly elastic, sensitive, and wearable sensors are obtained using the porous structure of sponge and the synergy effect of CNTs/Ag NPs. Our sensor was also tested for over 2000 compression-release cycles, exhibiting excellent elasticity and cycling stability. Sensors with high performance and a simple fabrication process are promising devices for commercial production in various electronic devices, for example, sport performance monitoring and man-machine interfaces. PMID:27482721

  6. Hybrid C-nanotubes/Si 3D nanostructures by one-step growth in a dual-plasma reactor

    NASA Astrophysics Data System (ADS)

    Toschi, Francesco; Orlanducci, Silvia; Guglielmotti, Valeria; Cianchetta, Ilaria; Magni, Corrado; Terranova, Maria Letizia; Pasquali, Matteo; Tamburri, Emanuela; Matassa, Roberto; Rossi, Marco

    2012-06-01

    Hybrid nanostructures consisting of Si polycrystalline nanocones, with an anemone-like termination coated with C-nanotubes bundles, have been generated on a (1 0 0) Si substrate in a dual mode microwave/radio-frequency plasma reactor. The substrate is both heated and bombarded by energetic H ions during the synthesis process. The nanocones growth is explained considering pull of the growing Si nanocrystalline phase along the lines of the electrical field, likely via a molten/recrystallization mechanism. The one-step building of the achieved complex 3D architectures is described in terms of dynamic competition between Si and C nanotubes growth under the peculiar conditions of kinetically driven processes.

  7. Piezoresistive Sensor with High Elasticity Based on 3D Hybrid Network of Sponge@CNTs@Ag NPs.

    PubMed

    Zhang, Hui; Liu, Nishuang; Shi, Yuling; Liu, Weijie; Yue, Yang; Wang, Siliang; Ma, Yanan; Wen, Li; Li, Luying; Long, Fei; Zou, Zhengguang; Gao, Yihua

    2016-08-31

    Pressure sensors with high elasticity are in great demand for the realization of intelligent sensing, but there is a need to develope a simple, inexpensive, and scalable method for the manufacture of the sensors. Here, we reported an efficient, simple, facile, and repeatable "dipping and coating" process to manufacture a piezoresistive sensor with high elasticity, based on homogeneous 3D hybrid network of carbon nanotubes@silver nanoparticles (CNTs@Ag NPs) anchored on a skeleton sponge. Highly elastic, sensitive, and wearable sensors are obtained using the porous structure of sponge and the synergy effect of CNTs/Ag NPs. Our sensor was also tested for over 2000 compression-release cycles, exhibiting excellent elasticity and cycling stability. Sensors with high performance and a simple fabrication process are promising devices for commercial production in various electronic devices, for example, sport performance monitoring and man-machine interfaces.

  8. A low order flow/acoustics interaction method for the prediction of sound propagation using 3D adaptive hybrid grids

    SciTech Connect

    Kallinderis, Yannis; Vitsas, Panagiotis A.; Menounou, Penelope

    2012-07-15

    A low-order flow/acoustics interaction method for the prediction of sound propagation and diffraction in unsteady subsonic compressible flow using adaptive 3-D hybrid grids is investigated. The total field is decomposed into the flow field described by the Euler equations, and the acoustics part described by the Nonlinear Perturbation Equations. The method is shown capable of predicting monopole sound propagation, while employment of acoustics-guided adapted grid refinement improves the accuracy of capturing the acoustic field. Interaction of sound with solid boundaries is also examined in terms of reflection, and diffraction. Sound propagation through an unsteady flow field is examined using static and dynamic flow/acoustics coupling demonstrating the importance of the latter.

  9. Thiol–ene-based biological/synthetic hybrid biomatrix for 3-D living cell culture

    PubMed Central

    Xu, Kedi; Fu, Yao; Chung, WeiJu; Zheng, Xiaoxiang; Cui, Yujia; Hsu, Ian C.; Kao, Weiyuan John

    2013-01-01

    Although various cell encapsulation materials are available commercially for a wide range of potential therapeutic cells, their combined clinical impact remains inconsistent. Synthetic materials such as poly(ethylene glycol) (PEG) hydrogels are mechanically robust and have been extensively explored but lack natural biofunctionality. Naturally derived materials including collagen, fibrin and alginate-chitosan are often labile and mechanically weak. In this paper we report the development of a hybrid biomatrix based on the thiol-ene reaction of PEG diacrylate (PEGdA) and cysteine/PEG-modified gelatin (gel-PEG-Cys). We hypothesized that covalent crosslinking decreases gelatin dissolution thus increasing gelatin resident time within the matrix and the duration of its biofunctionality; at the same time the relative ratio of PEGdA to gel-PEG-Cys in the matrix formulation directly affects hydrogel bulk and local microenvironment properties. Bulk viscoelastic properties were highly dependent on PEGdA concentration and total water content, while gel-PEG-Cys concentration was more critical to swelling profiles. Microviscoelastic properties were related to polymer concentration. The covalently crosslinked gel-PEG-Cys with PEGdA decreased gelatin dissolution out of the matrix and collagenase-mediated degradation. Fibroblasts and keratinocyte increased adhesion density and formed intercellular connections on stiffer hydrogel surfaces, while cells exhibited more cytoplasmic spreading and proliferation when entrapped within softer hydrogels. Hence, this material system contains multiparametric factors that can easily be controlled to modulate the chemical, physical and biological properties of the biomatrix for soft tissue scaffolding and cell presentation to reconstruct lost tissue architecture and physical functionality. PMID:22484717

  10. 3D hybrid simulations of the interaction of a magnetic cloud with a bow shock

    NASA Astrophysics Data System (ADS)

    Turc, L.; Fontaine, D.; Savoini, P.; Modolo, R.

    2015-08-01

    In this paper, we investigate the interaction of a magnetic cloud (MC) with a planetary bow shock using hybrid simulations. It is the first time to our knowledge that this interaction is studied using kinetic simulations which include self-consistently both the ion foreshock and the shock wave dynamics. We show that when the shock is in a quasi-perpendicular configuration, the MC's magnetic structure in the magnetosheath remains similar to that in the solar wind, whereas it is strongly altered downstream of a quasi-parallel shock. The latter can result in a reversal of the magnetic field north-south component in some parts of the magnetosheath. We also investigate how the MC affects in turn the outer parts of the planetary environment, i.e., from the foreshock to the magnetopause. We find the following: (i) The decrease of the Alfvén Mach number at the MC's arrival causes an attenuation of the foreshock region because of the weakening of the bow shock. (ii) The foreshock moves along the bow shock's surface, following the rotation of the MC's magnetic field. (iii) Owing to the low plasma beta, asymmetric flows arise inside the magnetosheath, due to the magnetic tension force which accelerates the particles in some parts of the magnetosheath and slows them down in others. (iv) The quasi-parallel region forms a depression in the shock's surface. Other deformations of the magnetopause and the bow shock are also highlighted. All these effects can contribute to significantly modify the solar wind/magnetosphere coupling during MC events.

  11. In vitro characterization of design and compressive properties of 3D-biofabricated/decellularized hybrid grafts for tracheal tissue engineering.

    PubMed

    Johnson, Christopher; Sheshadri, Priyanka; Ketchum, Jessica M; Narayanan, Lokesh K; Weinberger, Paul M; Shirwaiker, Rohan A

    2016-06-01

    Infection or damage to the trachea, a thin walled and cartilage reinforced conduit that connects the pharynx and larynx to the lungs, leads to serious respiratory medical conditions which can often prove fatal. Current clinical strategies for complex tracheal reconstruction are of limited availability and efficacy, but tissue engineering and regenerative medicine approaches may provide viable alternatives. In this study, we have developed a new "hybrid graft" approach that utilizes decellularized tracheal tissue along with a resorbable polymer scaffold, and holds promise for potential clinical applications. First, we evaluated the effect of our decellularization process on the compression properties of porcine tracheal segments, and noted approximately 63% decrease in resistance to compression following decellularization. Next we developed four C-shape scaffold designs by varying the base geometry and thickness, and fabricated polycaprolactone scaffolds using a combination of 3D-Bioplotting and thermally-assisted forming. All scaffolds designs were evaluated in vitro under three different environmental testing conditions to determine the design that offered the best resistance to compression. These were further studied to determine the effect of gamma radiation sterilization and cyclic compression loading. Finally, hybrid grafts were developed by securing these optimal design scaffolds to decellularized tracheal segments and evaluated in vitro under physiological testing conditions. Results show that the resistance to compression offered by the hybrid grafts created using gamma radiation sterilized scaffolds was comparable to that of fresh tracheal segments. Given that current clinical attempts at tracheal transplantation using decellularized tissue have been fraught with luminal collapse and complications, our data support the possibility that future embodiments using a hybrid graft approach may reduce the need for intraluminal stenting in tracheal transplant

  12. Hybrid Metrology and 3D-AFM Enhancement for CD Metrology Dedicated to 28 nm Node and Below Requirements

    SciTech Connect

    Foucher, J.; Faurie, P.; Dourthe, L.

    2011-11-10

    The measurement accuracy is becoming one of the major components that have to be controlled in order to guarantee sufficient production yield. Already at the R and D level, we have to come up with the accurate measurements of sub-40 nm dense trenches and contact holes coming from 193 immersion lithography or E-Beam lithography. Current production CD (Critical Dimension) metrology techniques such as CD-SEM (CD-Scanning Electron Microscope) and OCD (Optical Critical Dimension) are limited in relative accuracy for various reasons (i.e electron proximity effect, outputs parameters correlation, stack influence, electron interaction with materials...). Therefore, time for R and D is increasing, process windows degrade and finally production yield can decrease because you cannot manufactured correctly if you are unable to measure correctly. A new high volume manufacturing (HVM) CD metrology solution has to be found in order to improve the relative accuracy of production environment otherwise current CD Metrology solution will very soon get out of steam.In this paper, we will present a potential Hybrid CD metrology solution that smartly tuned 3D-AFM (3D-Atomic Force Microscope) and CD-SEM data in order to add accuracy both in R and D and production. The final goal for 'chip makers' is to improve yield and save R and D and production costs through real-time feedback loop implement on CD metrology routines. Such solution can be implemented and extended to any kind of CD metrology solution. In a 2{sup nd} part we will discuss and present results regarding a new AFM3D probes breakthrough with the introduction of full carbon tips made will E-Beam Deposition process. The goal is to overcome the current limitations of conventional flared silicon tips which are definitely not suitable for sub-32 nm nodes production.

  13. CQL3D-Hybrid-FOW modeling of the temporal dynamics of NSTX NBI+HHFW discharges

    SciTech Connect

    Harvey, R. W.; Petrov, Yu. V.; Liu, D.; Heidbrink, W. W.; Taylor, G.; Bonoli, P. T.

    2014-02-12

    The CQL3D Fokker-Planck code[1] has been upgraded to include physics of finite-orbit-width (FOW) guiding-center orbits[2,3], as compared with the previous zero-orbit-width (ZOW) model, and a recent first-order orbit calculation[2]. The Fast Ion Diagnostic FIDA[4,5] signal resulting from neutral beam (NBI) and high harmonic fast wave (HHFW) RF power injected into the NSTX spherical tokamak can now be modeled quite accurately, using ion distributions from the CQL3D-Hybrid-FOW code, a rapidly executing variant that includes FOW+gyro-orbit losses to the plasma edge, FOW effects on NBI injection and HHFW diffusion, but does not include neoclassical radial diffusion. Accurate simulation of prompt fast ion (FI) losses is a key feature of the marked modeling improvement relative to previous ZOW results. By comparing NBI-only and NBI+HHFW shots, independent confirmation of the usual 35% edge loss of HHFW in NSTX is obtained. Further, HHFW prompt losses from the plasma core are shown to be 3X as large (>25%) as the NBI-only case. The modulated NBI and time-dependent background plasma variations and charge exchange losses of fast ions are accounted for, and the temporal neutron variation is in approximate agreement with NSTX observations.

  14. CQL3D-Hybrid-FOW modeling of the temporal dynamics of NSTX NBI+HHFW discharges

    NASA Astrophysics Data System (ADS)

    Harvey, R. W.; Petrov, Yu. V.; Liu, D.; Heidbrink, W. W.; Taylor, G.; Bonoli, P. T.

    2014-02-01

    The CQL3D Fokker-Planck code[1] has been upgraded to include physics of finite-orbit-width (FOW) guiding-center orbits[2,3], as compared with the previous zero-orbit-width (ZOW) model, and a recent first-order orbit calculation[2]. The Fast Ion Diagnostic FIDA[4,5] signal resulting from neutral beam (NBI) and high harmonic fast wave (HHFW) RF power injected into the NSTX spherical tokamak can now be modeled quite accurately, using ion distributions from the CQL3D-Hybrid-FOW code, a rapidly executing variant that includes FOW+gyro-orbit losses to the plasma edge, FOW effects on NBI injection and HHFW diffusion, but does not include neoclassical radial diffusion. Accurate simulation of prompt fast ion (FI) losses is a key feature of the marked modeling improvement relative to previous ZOW results. By comparing NBI-only and NBI+HHFW shots, independent confirmation of the usual 35% edge loss of HHFW in NSTX is obtained. Further, HHFW prompt losses from the plasma core are shown to be 3X as large (>25%) as the NBI-only case. The modulated NBI and time-dependent background plasma variations and charge exchange losses of fast ions are accounted for, and the temporal neutron variation is in approximate agreement with NSTX observations.

  15. An innovative hybrid 3D analytic-numerical model for air breathing parallel channel counter-flow PEM fuel cells.

    PubMed

    Tavčar, Gregor; Katrašnik, Tomaž

    2014-01-01

    The parallel straight channel PEM fuel cell model presented in this paper extends the innovative hybrid 3D analytic-numerical (HAN) approach previously published by the authors with capabilities to address ternary diffusion systems and counter-flow configurations. The model's core principle is modelling species transport by obtaining a 2D analytic solution for species concentration distribution in the plane perpendicular to the cannel gas-flow and coupling consecutive 2D solutions by means of a 1D numerical pipe-flow model. Electrochemical and other nonlinear phenomena are coupled to the species transport by a routine that uses derivative approximation with prediction-iteration. The latter is also the core of the counter-flow computation algorithm. A HAN model of a laboratory test fuel cell is presented and evaluated against a professional 3D CFD simulation tool showing very good agreement between results of the presented model and those of the CFD simulation. Furthermore, high accuracy results are achieved at moderate computational times, which is owed to the semi-analytic nature and to the efficient computational coupling of electrochemical kinetics and species transport.

  16. An innovative hybrid 3D analytic-numerical model for air breathing parallel channel counter-flow PEM fuel cells.

    PubMed

    Tavčar, Gregor; Katrašnik, Tomaž

    2014-01-01

    The parallel straight channel PEM fuel cell model presented in this paper extends the innovative hybrid 3D analytic-numerical (HAN) approach previously published by the authors with capabilities to address ternary diffusion systems and counter-flow configurations. The model's core principle is modelling species transport by obtaining a 2D analytic solution for species concentration distribution in the plane perpendicular to the cannel gas-flow and coupling consecutive 2D solutions by means of a 1D numerical pipe-flow model. Electrochemical and other nonlinear phenomena are coupled to the species transport by a routine that uses derivative approximation with prediction-iteration. The latter is also the core of the counter-flow computation algorithm. A HAN model of a laboratory test fuel cell is presented and evaluated against a professional 3D CFD simulation tool showing very good agreement between results of the presented model and those of the CFD simulation. Furthermore, high accuracy results are achieved at moderate computational times, which is owed to the semi-analytic nature and to the efficient computational coupling of electrochemical kinetics and species transport. PMID:25125112

  17. Automatic C-arm pose estimation via 2D/3D hybrid registration of a radiographic fiducial

    NASA Astrophysics Data System (ADS)

    Moult, E.; Burdette, E. C.; Song, D. Y.; Abolmaesumi, P.; Fichtinger, G.; Fallavollita, P.

    2011-03-01

    Motivation: In prostate brachytherapy, real-time dosimetry would be ideal to allow for rapid evaluation of the implant quality intra-operatively. However, such a mechanism requires an imaging system that is both real-time and which provides, via multiple C-arm fluoroscopy images, clear information describing the three-dimensional position of the seeds deposited within the prostate. Thus, accurate tracking of the C-arm poses proves to be of critical importance to the process. Methodology: We compute the pose of the C-arm relative to a stationary radiographic fiducial of known geometry by employing a hybrid registration framework. Firstly, by means of an ellipse segmentation algorithm and a 2D/3D feature based registration, we exploit known FTRAC geometry to recover an initial estimate of the C-arm pose. Using this estimate, we then initialize the intensity-based registration which serves to recover a refined and accurate estimation of the C-arm pose. Results: Ground-truth pose was established for each C-arm image through a published and clinically tested segmentation-based method. Using 169 clinical C-arm images and a +/-10° and +/-10 mm random perturbation of the ground-truth pose, the average rotation and translation errors were 0.68° (std = 0.06°) and 0.64 mm (std = 0.24 mm). Conclusion: Fully automated C-arm pose estimation using a 2D/3D hybrid registration scheme was found to be clinically robust based on human patient data.

  18. A Non-Linear Inversion for the Global 3-D Electrical Conductivity Distribution in the Upper to Mid-Mantle

    NASA Astrophysics Data System (ADS)

    Kelbert, A.; Schultz, A.

    2004-12-01

    The case for substantial heterogeneity in mantle conductivity has stimulated the development of methods for solving Maxwell's equations in a heterogeneous conducting sphere. A global 3-D frequency domain forward solver has been devised (Uyeshima & Schultz, 2000), accurate and efficient enough to be an attractive kernel of a practical inverse method. The solver employs a staggered-grid finite difference formulation in spherical coordinates. The induced fields are found as a solution to the integral form of Maxwell's equations, while the system is solved using stabilised biconjugate gradient methods. A single, accurate forward solution takes approx. 4 minutes on 5 GFLOP (peak) processor. The aim of our present research is to produce an inverse solver, to be applied to the Fujii & Schultz (2002) data set of globally-distributed EM response functions, which would reconstruct the 3-D electrical conductivity distribution in the upper to mid-mantle. Geophysical inversion is an ill-posed problem, therefore the aim is to apply suitable parameter constraints and a nonlinear search algorithm to identify candidate minima, then to apply local gradient methods around those minima. Our specific target involves designing a fast enough global optimisation routine that would allow us to produce at least one fully 3-D starting model, optimal with respect to the RMS misfit between the data and the forward solutions. A new and very flexible inverse solver has been developed utilizing parallel optimisation routines to obtain a starting model that satisfies the data. 3-D simulations have been run, the parametrization based on a spherical harmonic representation of a chess board model of varying degree and order. The inversion has demonstrated accurate fidelity in reproducing resolvable features of the test model. A study has been made of the reduction in fidelity as the number and distribution of observatory sites on the Earth's surface is degraded. An inversion of the Fujii & Schultz

  19. Vessels as 4-D curves: global minimal 4-D paths to extract 3-D tubular surfaces and centerlines.

    PubMed

    Li, Hua; Yezzi, Anthony

    2007-09-01

    In this paper, we propose an innovative approach to the segmentation of tubular structures. This approach combines all of the benefits of minimal path techniques such as global minimizers, fast computation, and powerful incorporation of user input, while also having the capability to represent and detect vessel surfaces directly which so far has been a feature restricted to active contour and surface techniques. The key is to represent the trajectory of a tubular structure not as a 3-D curve but to go up a dimension and represent the entire structure as a 4-D curve. Then we are able to fully exploit minimal path techniques to obtain global minimizing trajectories between two user supplied endpoints in order to reconstruct tubular structures from noisy or low contrast 3-D data without the sensitivity to local minima inherent in most active surface techniques. In contrast to standard purely spatial 3-D minimal path techniques, however, we are able to represent a full tubular surface rather than just a curve which runs through its interior. Our representation also yields a natural notion of a tube's "central curve." We demonstrate and validate the utility of this approach on magnetic resonance (MR) angiography and computed tomography (CT) images of coronary arteries. PMID:17896594

  20. Ion foreshock and magnetosheath properties in global hybrid simulations

    NASA Astrophysics Data System (ADS)

    Hercik, D.; Travnicek, P. M.; Schriver, D.; Hellinger, P.

    2010-12-01

    Properties of the interaction between the solar wind and magnetized small bodies is investigated using 3-D global hybrid simulations (Travnicek et al., 2009, 2010). We investigate the ion foreshock, formation and properties of the back-streaming proton population and the corresponding wave activity. We also investigate properties of the quasi-parallel shock and the adjacent magnetosheath. The properties of the quasi-parallel magnetosheath are compared with the properties of the quasi-perpendicular one. References Travnicek, P. M., P. Hellinger, D. Schriver, D. Hercik, J.A. Slavin, and B. J. Anderson (2009), Kinetic instabilities in Mercury's magnetosphere: three-dimensional simulatin results, Geophys. Res. Lett., 36, L07104,2009 Travnicek,P. M., D. Schriver, P. Hellinger, D. Hercik, B.J. Anderson, M Sarantos, and J.A. Slavin (2010), Mercury's magnetosphere-solar wind interaction for northward and southward interplanetary magnetic field: Hybrid simulation results, Icarus,209,11-22

  1. Development of a hybrid 3-D hydrological model to simulate hillslopes and the regional unconfined aquifer system in Earth system models

    NASA Astrophysics Data System (ADS)

    Hazenberg, P.; Broxton, P. D.; Brunke, M.; Gochis, D.; Niu, G. Y.; Pelletier, J. D.; Troch, P. A. A.; Zeng, X.

    2015-12-01

    The terrestrial hydrological system, including surface and subsurface water, is an essential component of the Earth's climate system. Over the past few decades, land surface modelers have built one-dimensional (1D) models resolving the vertical flow of water through the soil column for use in Earth system models (ESMs). These models generally have a relatively coarse model grid size (~25-100 km) and only account for sub-grid lateral hydrological variations using simple parameterization schemes. At the same time, hydrologists have developed detailed high-resolution (~0.1-10 km grid size) three dimensional (3D) models and showed the importance of accounting for the vertical and lateral redistribution of surface and subsurface water on soil moisture, the surface energy balance and ecosystem dynamics on these smaller scales. However, computational constraints have limited the implementation of the high-resolution models for continental and global scale applications. The current work presents a hybrid-3D hydrological approach is presented, where the 1D vertical soil column model (available in many ESMs) is coupled with a high-resolution lateral flow model (h2D) to simulate subsurface flow and overland flow. H2D accounts for both local-scale hillslope and regional-scale unconfined aquifer responses (i.e. riparian zone and wetlands). This approach was shown to give comparable results as those obtained by an explicit 3D Richards model for the subsurface, but improves runtime efficiency considerably. The h3D approach is implemented for the Delaware river basin, where Noah-MP land surface model (LSM) is used to calculated vertical energy and water exchanges with the atmosphere using a 10km grid resolution. Noah-MP was coupled within the WRF-Hydro infrastructure with the lateral 1km grid resolution h2D model, for which the average depth-to-bedrock, hillslope width function and soil parameters were estimated from digital datasets. The ability of this h3D approach to simulate

  2. A global 3-D MHD model of the solar wind with Alfven waves

    NASA Technical Reports Server (NTRS)

    Usmanov, A. V.

    1995-01-01

    A fully three-dimensional solar wind model that incorporates momentum and heat addition from Alfven waves is developed. The proposed model upgrades the previous one by considering self-consistently the total system consisting of Alfven waves propagating outward from the Sun and the mean polytropic solar wind flow. The simulation region extends from the coronal base (1 R(sub s) out to beyond 1 AU. The fully 3-D MHD equations written in spherical coordinates are solved in the frame of reference corotating with the Sun. At the inner boundary, the photospheric magnetic field observations are taken as boundary condition and wave energy influx is prescribed to be proportional to the magnetic field strength. The results of the model application for several time intervals are presented.

  3. Multi-sensor super-resolution for hybrid range imaging with application to 3-D endoscopy and open surgery.

    PubMed

    Köhler, Thomas; Haase, Sven; Bauer, Sebastian; Wasza, Jakob; Kilgus, Thomas; Maier-Hein, Lena; Stock, Christian; Hornegger, Joachim; Feußner, Hubertus

    2015-08-01

    In this paper, we propose a multi-sensor super-resolution framework for hybrid imaging to super-resolve data from one modality by taking advantage of additional guidance images of a complementary modality. This concept is applied to hybrid 3-D range imaging in image-guided surgery, where high-quality photometric data is exploited to enhance range images of low spatial resolution. We formulate super-resolution based on the maximum a-posteriori (MAP) principle and reconstruct high-resolution range data from multiple low-resolution frames and complementary photometric information. Robust motion estimation as required for super-resolution is performed on photometric data to derive displacement fields of subpixel accuracy for the associated range images. For improved reconstruction of depth discontinuities, a novel adaptive regularizer exploiting correlations between both modalities is embedded to MAP estimation. We evaluated our method on synthetic data as well as ex-vivo images in open surgery and endoscopy. The proposed multi-sensor framework improves the peak signal-to-noise ratio by 2 dB and structural similarity by 0.03 on average compared to conventional single-sensor approaches. In ex-vivo experiments on porcine organs, our method achieves substantial improvements in terms of depth discontinuity reconstruction.

  4. A global model simulation for 3-D radiative transfer impact on surface hydrology over the Sierra Nevada and Rocky Mountains

    DOE PAGES

    Lee, W.-L.; Gu, Y.; Liou, K. N.; Leung, L. R.; Hsu, H.-H.

    2015-05-19

    We investigate 3-D mountain effects on solar flux distributions and their impact on surface hydrology over the western United States, specifically the Rocky Mountains and the Sierra Nevada, using the global CCSM4 (Community Climate System Model version 4; Community Atmosphere Model/Community Land Model – CAM4/CLM4) with a 0.23° × 0.31° resolution for simulations over 6 years. In a 3-D radiative transfer parameterization, we have updated surface topography data from a resolution of 1 km to 90 m to improve parameterization accuracy. In addition, we have also modified the upward-flux deviation (3-D–PP (plane-parallel)) adjustment to ensure that the energy balance atmore » the surface is conserved in global climate simulations based on 3-D radiation parameterization. We show that deviations in the net surface fluxes are not only affected by 3-D mountains but also influenced by feedbacks of cloud and snow in association with the long-term simulations. Deviations in sensible heat and surface temperature generally follow the patterns of net surface solar flux. The monthly snow water equivalent (SWE) deviations show an increase in lower elevations due to reduced snowmelt, leading to a reduction in cumulative runoff. Over higher-elevation areas, negative SWE deviations are found because of increased solar radiation available at the surface. Simulated precipitation increases for lower elevations, while it decreases for higher elevations, with a minimum in April. Liquid runoff significantly decreases at higher elevations after April due to reduced SWE and precipitation.« less

  5. Turbulent saturation and transport in global 3D two-fluid simulations of the tokamak edge

    NASA Astrophysics Data System (ADS)

    Rogers, Barrett; Ricci, Paolo

    2012-03-01

    Based on nonlinear, global, three-dimensional two-fluid simulations, we explore the physics of turbulent saturation and transport in the tokamak scape-off layer and other magnetic geometries. We find that the global simulations can produce larger relative fluctuation amplitudes and more Bohm-like (versus Gyro-Bohm-like) transport scalings than those of non-global (flux-tube) simulations. In both the global and local simulations, small-scale primary instabilities such as driftwaves or resistive ballooning modes produce radial streamers, which grow until they are broken up by secondary modes such as the Kelvin-Helmholz instability or related modes. In a local simulation with fixed, radially constant equilibrium gradients and periodic boundaries, for example, the radial elongation of these primary-mode streamers is, in principle, unlimited. In the global simulations, however, the radial extent of the primaries is truncated by the nonlocal radial variations of the equilibrium profile gradients, typically to the geometric mean of the equilibrium profile scale-length and poloidal scale-length of the primary modes. This radial truncation can have a strongly stabilizing effect on the KH mode, leading to larger primary-mode fluctuation levels and non-Gyro-Bohm transport scaling.

  6. Validation of "AW3D" Global Dsm Generated from Alos Prism

    NASA Astrophysics Data System (ADS)

    Takaku, Junichi; Tadono, Takeo; Tsutsui, Ken; Ichikawa, Mayumi

    2016-06-01

    Panchromatic Remote-sensing Instrument for Stereo Mapping (PRISM), one of onboard sensors carried by Advanced Land Observing Satellite (ALOS), was designed to generate worldwide topographic data with its optical stereoscopic observation. It has an exclusive ability to perform a triplet stereo observation which views forward, nadir, and backward along the satellite track in 2.5 m ground resolution, and collected its derived images all over the world during the mission life of the satellite from 2006 through 2011. A new project, which generates global elevation datasets with the image archives, was started in 2014. The data is processed in unprecedented 5 m grid spacing utilizing the original triplet stereo images in 2.5 m resolution. As the number of processed data is growing steadily so that the global land areas are almost covered, a trend of global data qualities became apparent. This paper reports on up-to-date results of the validations for the accuracy of data products as well as the status of data coverage in global areas. The accuracies and error characteristics of datasets are analyzed by the comparison with existing global datasets such as Ice, Cloud, and land Elevation Satellite (ICESat) data, as well as ground control points (GCPs) and the reference Digital Elevation Model (DEM) derived from the airborne Light Detection and Ranging (LiDAR).

  7. Global 3D-Grids Based on Great Circle Arc QTM Sphere Octree and Its Application

    NASA Astrophysics Data System (ADS)

    Wang, J. X.; Li, Y. H.; Zheng, Y. S.; Liu, J. N.

    2013-10-01

    With the development of computers, network communications, scientific computing, mapping remote sensing and geographic information technologies, Discrete Global Grids (DGGs) and Earth System Spatial Grid(ESSG)have become the integrated spatial data model facing the large-scale and global-scale problems and the complex geo-computation. This paper discusses the property and character of the global spatial data at first. Then it introduces the grid division system based on large arc QTM octree and compares this scheme with degradation octree scheme. At last, it introduces the application of the scheme in land surface, underground and aerial geographic entity modeling. The study suggests that: the grid division system based on large arc QTM octree has the potential to integrate the whole spatial data of different layers of the geospatial. And it will have a broad application prospect in complex large-scale geographic computing.

  8. Titan's plasma environment: 3D hybrid kinetic modeling of the TA flyby and comparison with CAPS-ELS and RPWS LP observations

    NASA Astrophysics Data System (ADS)

    Lipatov, A. S.; Sittler, E. C.; Hartle, R. E.; Cooper, J. F.; Simpson, D. G.

    2014-04-01

    In this report we discuss the global plasma environment of the TA flyby from the perspective of 3D hybrid modeling. In our model the background, pickup, and ionospheric ions are considered as particles, whereas the electrons are described as a fluid. Inhomogeneous photoionization, electron-impact ionization and charge exchange are included in our model. We also take into account the collisions between the ions and neutrals. Our modeling shows that mass loading of the background plasma (H+, O+) by pickup ions H2+, CH4+ and N2+ differs from the T9 encounter simulations when O+ ions are not introduced into the background plasma. In our hybrid modeling we use Chamberlain profiles for the atmospheric components. We also include a simple ionosphere model with average mass M=28 amu ions that were generated inside the ionosphere. Titan's interior is considered as a weakly conducting body. Special attention has been paid to comparing the simulated pickup ion density distribution with CAPS-ELS and with RPWS LP observations by the Cassini-Huygens spacecraft along the TA trajectory. Our modeling shows an asymmetry of the ion density distribution and the magnetic field, including the formation of Alfvén wing-like structures.

  9. Modeling Recent Large Earthquakes Using the 3-D Global Wave Field

    NASA Astrophysics Data System (ADS)

    Hjörleifsdóttir, V.; Kanamori, H.; Tromp, J.

    2003-04-01

    We use the spectral-element method (SEM) to accurately compute waveforms at periods of 40 s and longer for three recent large earthquakes using 3D Earth models and finite source models. The M_w~7.6, Jan~26, 2001, Bhuj, India event had a small rupture area and is well modeled at long periods with a point source. We use this event as a calibration event to investigate the effects of 3-D Earth models on the waveforms. The M_w~7.9, Nov~11, 2001, Kunlun, China, event exhibits a large directivity (an asymmetry in the radiation pattern) even at periods longer than 200~s. We used the source time function determined by Kikuchi and Yamanaka (2001) and the overall pattern of slip distribution determined by Lin et al. to guide the wave-form modeling. The large directivity is consistent with a long fault, at least 300 km, and an average rupture speed of 3±0.3~km/s. The directivity at long periods is not sensitive to variations in the rupture speed along strike as long as the average rupture speed is constant. Thus, local variations in rupture speed cannot be ruled out. The rupture speed is a key parameter for estimating the fracture energy of earthquakes. The M_w~8.1, March~25, 1998, event near the Balleny Islands on the Antarctic Plate exhibits large directivity in long period surface waves, similar to the Kunlun event. Many slip models have been obtained from body waves for this earthquake (Kuge et al. (1999), Nettles et al. (1999), Antolik et al. (2000), Henry et al. (2000) and Tsuboi et al. (2000)). We used the slip model from Henry et al. to compute SEM waveforms for this event. The synthetic waveforms show a good fit to the data at periods from 40-200~s, but the amplitude and directivity at longer periods are significantly smaller than observed. Henry et al. suggest that this event comprised two subevents with one triggering the other at a distance of 100 km. To explain the observed directivity however, a significant amount of slip is required between the two subevents

  10. Connecting Global Measures of 3D Magnetic Reconnection to Local Kinetic Physics

    SciTech Connect

    Daughton, William Scott

    2015-07-16

    After giving the motivation for the work, slides present the topic under the following headings: Description of LAPD experiment; Actual simulation setup; Simple kinetic theory of ined-tied tearing; Diagnostics to characterizing 3D reconnection; Example #1 - short-tied system; and Example #2 - long line-tied system. Colorful simulations are shown for quasipotential vs field line exponentiation, field line integrated Ohms Law, and correlation with agyrotopy & energy conversion for example #1; and evolution of current density for largest case, field exponentiation vs quasi-potential, and time evolution of magnetic field lines for example #2. To satisfy line-tied boundary conditions, there is need for superposition of oblique modes--the simple two-mode approximation works surprisingly well. For force-free layers with bg >1, the fastest growing periodic modes are oblique with kxλ ~0.5. This implies a minimum length of Ly > 2πλbg. There are strong correlations between σ → Ξ → A0e (observable with spacecraft). Electron pressure tensor is the dominant non-ideal term.

  11. Global impact of the Antarctic ozone hole: Simulations with a 3-D chemical transport model

    NASA Technical Reports Server (NTRS)

    Prather, Michael J.; Garcia, Maria M.

    1988-01-01

    A study of the Antarctic ozone hole was made with a 3-D chemical transport model using linearized photochemistry for ozone based on observed distribution. The tracer model uses the winds and convection from the GISS general circulation model (8 deg x 10 deg x 23 layers). A 3-year control run of the ozone distribution is compared with the observed climatology. In two experiments, a hypothetical Antarctic ozone hole is induced on October 1 and on November 1; the tracer model is integrated for 1 year with the standard linearized chemistry. The initial depletion, 90 percent of the O sub 3 poleward of 70 S between 25 and 180 mbar, amounts to about 5 percent of the total O sub 3 in the Southerm Hemisphere. As the vortex breaks down and the hole is dispersed, significant depletions to column ozone, of order 10 D.U., occur as far north as 36 S during Austral summer. One year later, about 25 percent of the original depletion remains, mostly below 100 mbar and poleward of 30 S. Details of the calculations are shown, along with a budget analysis showing the fraction of the hole filled in by photochemistry versus that transported into the troposhere.

  12. New 3D parallel GILD electromagnetic modeling and nonlinear inversion using global magnetic integral and local differential equation

    SciTech Connect

    Xie, G.; Li, J.; Majer, E.; Zuo, D.

    1998-07-01

    This paper describes a new 3D parallel GILD electromagnetic (EM) modeling and nonlinear inversion algorithm. The algorithm consists of: (a) a new magnetic integral equation instead of the electric integral equation to solve the electromagnetic forward modeling and inverse problem; (b) a collocation finite element method for solving the magnetic integral and a Galerkin finite element method for the magnetic differential equations; (c) a nonlinear regularizing optimization method to make the inversion stable and of high resolution; and (d) a new parallel 3D modeling and inversion using a global integral and local differential domain decomposition technique (GILD). The new 3D nonlinear electromagnetic inversion has been tested with synthetic data and field data. The authors obtained very good imaging for the synthetic data and reasonable subsurface EM imaging for the field data. The parallel algorithm has high parallel efficiency over 90% and can be a parallel solver for elliptic, parabolic, and hyperbolic modeling and inversion. The parallel GILD algorithm can be extended to develop a high resolution and large scale seismic and hydrology modeling and inversion in the massively parallel computer.

  13. Free-space coherent optical communication with orbital angular, momentum multiplexing/demultiplexing using a hybrid 3D photonic integrated circuit.

    PubMed

    Guan, Binbin; Scott, Ryan P; Qin, Chuan; Fontaine, Nicolas K; Su, Tiehui; Ferrari, Carlo; Cappuzzo, Mark; Klemens, Fred; Keller, Bob; Earnshaw, Mark; Yoo, S J B

    2014-01-13

    We demonstrate free-space space-division-multiplexing (SDM) with 15 orbital angular momentum (OAM) states using a three-dimensional (3D) photonic integrated circuit (PIC). The hybrid device consists of a silica planar lightwave circuit (PLC) coupled to a 3D waveguide circuit to multiplex/demultiplex OAM states. The low excess loss hybrid device is used in individual and two simultaneous OAM states multiplexing and demultiplexing link experiments with a 20 Gb/s, 1.67 b/s/Hz quadrature phase shift keyed (QPSK) signal, which shows error-free performance for 379,960 tested bits for all OAM states.

  14. 3D Dynamics of Magnetopause Reconnection Using Hall-MHD Global Simulations

    NASA Astrophysics Data System (ADS)

    Maynard, K.; Germaschewski, K.; Raeder, J.; Bhattacharjee, A.

    2011-12-01

    Magnetic reconnection at Earth's magnetopause and in the magnetotail is of crucial importance for the dynamics of the global magnetosphere and space weather. Even though the plasma conditions in the magnetosphere are largely in the collisionless regime, most of the existing research using global computational models employ single-fluid magnetohydrodynamics (MHD) with artificial resistivity. Studies of reconnection in simplified, two-dimensional geometries have established that two-fluid and kinetic effects can dramatically alter dynamics and reconnection rates when compared with single-fluid models. These enhanced models also introduce particular signatures, for example a quadrupolar out-of-plane magnetic field component that has already been observed in space by satellite measurements. However, results from simplified geometries cannot be translated directly to the dynamics of three-dimensional magnetospheric reconnection. For instance, magnetic flux originating from the solar wind and arriving at the magnetopause can either reconnect or be advected around the magnetosphere. In this study, we use a new version of the OpenGGCM code that incorporates the Hall term in a Generalized Ohm's Law to study magnetopause reconnection under synthetic solar wind conditions and investigate how reconnection rates and dynamics of flux transfer events depend on the strength of the Hall term. The OpenGGCM, a global model of Earth's magnetosphere, has recently been ported to exploit modern computing architectures like the Cell processor and SIMD capabilities of conventional processors using an automatic code generator. These enhancements provide us with the performance needed to include the computationally expensive Hall physics.

  15. A New Global Model for 3-D variations in P Wave Speed in Earth's Mantle

    NASA Astrophysics Data System (ADS)

    Karason, H.; van der Hilst, R. D.; Li, C.

    2003-12-01

    In an effort to improve the resolution of mantle structure we have combined complementary data sets of short- and long period (absolute and differential) travel time residuals. Our new model is based on short period P (N\\~7.7x10**6), pP (N\\~2.3x10**5), and PKP (N\\~16x10**4) data from the catalog by Engdahl et al (BSSA, 1998), short-period PKP differential times (N\\~1600) measured by McSweeney & Creager, and long-period differential PP-P times - N\\~20,000 measured by Bolton & Masters and N\\~18,000 by Ritsema - and Pdiff-PKP (N\\~560) measured by Wysession. Inversion tests, spectral analysis, and comparison with geology indicate that the large-scale upper mantle structure is better constrained with the addition of PP-P, whereas the Pdiff and PKP data help constrain deep mantle structure (Karason & Van der Hilst, JGR, 2001). The long period data were measured by cross-correlation. We solved the system of equations using 400 iterations of the iterative algorithm LSQR For the short period (1 Hz) data we use a high frequency approximation and trace rays through a fine grid of constant slowness cells to invert for mantle structure. For low frequency Pdiff and PP data we account for sensitivity to structure away from the optical ray path with 3-D Frechet derivatives (sensitivity kernels) estimated from single forward scattering and projected onto basis functions (constant slowness blocks) used for model parameterization. With such kernels the low frequency data can constrain long wavelength heterogeneity without keeping the short period data from mapping details in densely sampled regions. In addition to finite frequency sensitivity kernels we optimized the localization by using a parameterization that adapts to spatial resolution, with small cells in regions of dense sampling and larger cells in regions where sampling is more sparse (the total number of cells was \\~ 350,000). Finally, we corrected all travel times and surface reflections for lateral variations in

  16. Characterization of global flow and local fluctuations in 3D SPH simulations of protoplanetary discs

    NASA Astrophysics Data System (ADS)

    Arena, S. E.; Gonzalez, J.-F.

    2013-07-01

    A complete and detailed knowledge of the structure of the gaseous component in protoplanetary discs is essential to the study of dust evolution during the early phases of pre-planetesimal formation. The aim of this paper is to determine if three-dimensional accretion discs simulated by the smoothed particle hydrodynamics (SPH) method can reproduce the observational data now available and the expected turbulent nature of protoplanetary discs. The investigation is carried out by setting up a suite of diagnostic tools specifically designed to characterize both the global flow and the fluctuations of the gaseous disc. The main result concerns the role of the artificial viscosity implementation in the SPH method: in addition to the already known ability of SPH artificial viscosity to mimic a physical-like viscosity under specific conditions, we show how the same artificial viscosity prescription behaves like an implicit turbulence model. In fact, we identify a threshold for the parameters in the standard artificial viscosity above which SPH disc models present a cascade in the power spectrum of velocity fluctuations, turbulent diffusion and a mass accretion rate of the same order of magnitude as measured in observations. Furthermore, the turbulence properties observed locally in SPH disc models are accompanied by meridional circulation in the global flow of the gas, proving that the two mechanisms can coexist.

  17. Comparisons of 3D data products of the global atmosphere for the past 120 years

    NASA Astrophysics Data System (ADS)

    Brönnimann, Stefan; Stickler, Alexander; Compo, Gilbert P.

    2010-05-01

    In order to better understand, assess, and eventually predict climate variability and extremes, global 3-dimensional data sets of the atmosphere over a sufficiently long time period are needed. Until recently, there were mainly two reanalyses (NCEP/NCAR and ERA-40), which covered the second half of the 20th century. These are the most widely used data sets in atmospheric and climate science, but the period covered is still too short for many purposes. In cooperation with the Atmospheric Circulation Reconstructions over the Earth initiative (R. Allan, UK Met Office, www.met-acre.org/), different data products have been developed recently that allow a 4-dimensional view of the global atmosphere further back than the mid 20th century. These data sets include the Twentieth Century Reanalysis Project (G. P. Compo, P. Sardeshmukh & J. Whitaker, CU/CIRES/CDC and NOAA/ESRL, http://www.esrl.noaa.gov/psd/data/20thC_Rean/), monthly statistical reconstructions, and a new collection of historical upper-air data (CHUAN, see www.historicalupperair.org). In this presentation we show comparisons of the different data products for several case studies as well as statistically using independent data.

  18. Particle entry through "Sash" groove simulated by Global 3D Electromagnetic Particle code with duskward IMF By

    NASA Astrophysics Data System (ADS)

    Yan, X.; Cai, D.; Nishikawa, K.; Lembege, B.

    2004-12-01

    We made our efforts to parallelize the global 3D HPF Electromagnetic particle model (EMPM) for several years and have also reported our meaningful simulation results that revealed the essential physics involved in interaction of the solar wind with the Earth's magnetosphere using this EMPM (Nishikawa et al., 1995; Nishikawa, 1997, 1998a, b, 2001, 2002) in our PC cluster and supercomputer(D.S. Cai et al., 2001, 2003). Sash patterns and related phenomena have been observed and reported in some satellite observations (Fujumoto et al. 1997; Maynard, 2001), and have motivated 3D MHD simulations (White and al., 1998). We also investigated it with our global 3D parallelized HPF EMPM with dawnward IMF By (K.-I. Nishikawa, 1998) and recently new simulation with dusk-ward IMF By was accomplished in the new VPP5000 supercomputer. In the new simulations performed on the new VPP5000 supercomputer of Tsukuba University, we used larger domain size, 305×205×205, smaller grid size (Δ ), 0.5R E(the radium of the Earth), more total particle number, 220,000,000 (about 8 pairs per cell). At first, we run this code until we get the so-called quasi-stationary status; After the quasi-stationary status was established, we applied a northward IMF (B z=0.2), and then wait until the IMF arrives around the magnetopuase. After the arrival of IMF, we begin to change the IMF from northward to duskward (IMF B y=-0.2). The results revealed that the groove structure at the day-side magnetopause, that causes particle entry into inner magnetosphere and the cross structure or S-structure at near magneto-tail are formed. Moreover, in contrast with MHD simulations, kinetic characteristic of this event is also analyzed self-consistently with this simulation. The new simulation provides new and more detailed insights for the observed sash event.

  19. Fast and accurate global multiphase arrival tracking: the irregular shortest-path method in a 3-D spherical earth model

    NASA Astrophysics Data System (ADS)

    Huang, Guo-Jiao; Bai, Chao-Ying; Greenhalgh, Stewart

    2013-09-01

    The traditional grid/cell-based wavefront expansion algorithms, such as the shortest path algorithm, can only find the first arrivals or multiply reflected (or mode converted) waves transmitted from subsurface interfaces, but cannot calculate the other later reflections/conversions having a minimax time path. In order to overcome the above limitations, we introduce the concept of a stationary minimax time path of Fermat's Principle into the multistage irregular shortest path method. Here we extend it from Cartesian coordinates for a flat earth model to global ray tracing of multiple phases in a 3-D complex spherical earth model. The ray tracing results for 49 different kinds of crustal, mantle and core phases show that the maximum absolute traveltime error is less than 0.12 s and the average absolute traveltime error is within 0.09 s when compared with the AK135 theoretical traveltime tables for a 1-D reference model. Numerical tests in terms of computational accuracy and CPU time consumption indicate that the new scheme is an accurate, efficient and a practical way to perform 3-D multiphase arrival tracking in regional or global traveltime tomography.

  20. Mars-solar wind interaction: LatHyS, an improved parallel 3-D multispecies hybrid model

    NASA Astrophysics Data System (ADS)

    Modolo, Ronan; Hess, Sebastien; Mancini, Marco; Leblanc, Francois; Chaufray, Jean-Yves; Brain, David; Leclercq, Ludivine; Esteban-Hernández, Rosa; Chanteur, Gerard; Weill, Philippe; González-Galindo, Francisco; Forget, Francois; Yagi, Manabu; Mazelle, Christian

    2016-07-01

    In order to better represent Mars-solar wind interaction, we present an unprecedented model achieving spatial resolution down to 50 km, a so far unexplored resolution for global kinetic models of the Martian ionized environment. Such resolution approaches the ionospheric plasma scale height. In practice, the model is derived from a first version described in Modolo et al. (2005). An important effort of parallelization has been conducted and is presented here. A better description of the ionosphere was also implemented including ionospheric chemistry, electrical conductivities, and a drag force modeling the ion-neutral collisions in the ionosphere. This new version of the code, named LatHyS (Latmos Hybrid Simulation), is here used to characterize the impact of various spatial resolutions on simulation results. In addition, and following a global model challenge effort, we present the results of simulation run for three cases which allow addressing the effect of the suprathermal corona and of the solar EUV activity on the magnetospheric plasma boundaries and on the global escape. Simulation results showed that global patterns are relatively similar for the different spatial resolution runs, but finest grid runs provide a better representation of the ionosphere and display more details of the planetary plasma dynamic. Simulation results suggest that a significant fraction of escaping O+ ions is originated from below 1200 km altitude.

  1. A Global 3D Radiation MHD Simulation of Super-Eddington Accretion Disks

    NASA Astrophysics Data System (ADS)

    Jiang, Yanfei

    2014-10-01

    We study how black holes can accrete above the Eddington limit using a global three dimensional radiation magneto-hydrodynamic simulation without ad-hoc assumptions. The simulation reaches an accretion rate ~ 220L_Edd/c^2 and forms a radiation driven outflow along the rotation axis. The radiative luminosity of this flow is ~ 10L_Edd. This yields a radiative efficiency ~ 4.5%, which is comparable to the value in a standard thin disk model. In our simulation, vertical advection of radiation caused by magnetic buoyancy transports energy faster than photon diffusion, allowing a significant fraction of the photons to escape from the surface of the disk before being advected into the black hole. We contrast our results with the lower radiative efficiencies inferred in slim disk model, which neglect vertical advection. The results have important implications for the growth of supermassive black holes in the early universe, tidal disruption events and ultra-luminous X-ray sources.

  2. Global localization of 3D anatomical structures by pre-filtered Hough forests and discrete optimization.

    PubMed

    Donner, René; Menze, Bjoern H; Bischof, Horst; Langs, Georg

    2013-12-01

    The accurate localization of anatomical landmarks is a challenging task, often solved by domain specific approaches. We propose a method for the automatic localization of landmarks in complex, repetitive anatomical structures. The key idea is to combine three steps: (1) a classifier for pre-filtering anatomical landmark positions that (2) are refined through a Hough regression model, together with (3) a parts-based model of the global landmark topology to select the final landmark positions. During training landmarks are annotated in a set of example volumes. A classifier learns local landmark appearance, and Hough regressors are trained to aggregate neighborhood information to a precise landmark coordinate position. A non-parametric geometric model encodes the spatial relationships between the landmarks and derives a topology which connects mutually predictive landmarks. During the global search we classify all voxels in the query volume, and perform regression-based agglomeration of landmark probabilities to highly accurate and specific candidate points at potential landmark locations. We encode the candidates' weights together with the conformity of the connecting edges to the learnt geometric model in a Markov Random Field (MRF). By solving the corresponding discrete optimization problem, the most probable location for each model landmark is found in the query volume. We show that this approach is able to consistently localize the model landmarks despite the complex and repetitive character of the anatomical structures on three challenging data sets (hand radiographs, hand CTs, and whole body CTs), with a median localization error of 0.80 mm, 1.19 mm and 2.71 mm, respectively. PMID:23664450

  3. Global localization of 3D anatomical structures by pre-filtered Hough Forests and discrete optimization

    PubMed Central

    Donner, René; Menze, Bjoern H.; Bischof, Horst; Langs, Georg

    2013-01-01

    The accurate localization of anatomical landmarks is a challenging task, often solved by domain specific approaches. We propose a method for the automatic localization of landmarks in complex, repetitive anatomical structures. The key idea is to combine three steps: (1) a classifier for pre-filtering anatomical landmark positions that (2) are refined through a Hough regression model, together with (3) a parts-based model of the global landmark topology to select the final landmark positions. During training landmarks are annotated in a set of example volumes. A classifier learns local landmark appearance, and Hough regressors are trained to aggregate neighborhood information to a precise landmark coordinate position. A non-parametric geometric model encodes the spatial relationships between the landmarks and derives a topology which connects mutually predictive landmarks. During the global search we classify all voxels in the query volume, and perform regression-based agglomeration of landmark probabilities to highly accurate and specific candidate points at potential landmark locations. We encode the candidates’ weights together with the conformity of the connecting edges to the learnt geometric model in a Markov Random Field (MRF). By solving the corresponding discrete optimization problem, the most probable location for each model landmark is found in the query volume. We show that this approach is able to consistently localize the model landmarks despite the complex and repetitive character of the anatomical structures on three challenging data sets (hand radiographs, hand CTs, and whole body CTs), with a median localization error of 0.80 mm, 1.19 mm and 2.71 mm, respectively. PMID:23664450

  4. 2D and 3D alkaline earth metal carboxyphosphonate hybrids: Anti-corrosion coatings for metal surfaces

    SciTech Connect

    Demadis, Konstantinos D. Papadaki, Maria; Raptis, Raphael G.; Zhao, Hong

    2008-03-15

    Reactions of Mg{sup 2+} (1), Ca{sup 2+} (2), Sr{sup 2+} (3), or Ba{sup 2+} (4) salts with hydroxyphosphonoacetic acid (HPAA) at a 1:1 ratio yield M-HPAA layered coordination polymers. The crystal structures of 3 (two phases) and 4 have been determined by single crystal X-ray crystallography. Both stereoisomers (R and S) of HPAA are incorporated in the metal-HPAA materials. Synergistic combinations of Sr{sup 2+} or Ba{sup 2+} and HPAA at pH 7.3 are effective corrosion inhibitors for carbon steel, but are ineffective at pH 2.0. - Graphical abstract: Syntheses, characterization and crystal structures of metal-hydroxyphosphonoacetate hybrids are reported (Metal=Sr, Ba). 2D and 3D materials were prepared. Their anti-corrosion effects were studied at pH 2.0 and 7.3. It was found that anti-corrosion efficiency was demonstrated only at pH 7.3.

  5. First Lunar Wake Passage of ARTEMIS: Discrimination of Wake Effects and Solar Wind Fluctuations by 3D Hybrid Simulations

    NASA Technical Reports Server (NTRS)

    Wiehle, S.; Plaschke, F.; Motschmann, U.; Glassmeier, K. H.; Auster, H. U.; Angelopoulos, V.; Mueller, J.; Kriegel, H.; Georgescu, E.; Halekas, J.; Sibeck, D. G.; McFadden, J. P.

    2011-01-01

    The spacecraft P1 of the new ARTEMIS (Acceleration, Reconnection, Turbulence, and Electrodynamics of the Moon's Interaction with the Sun) mission passed the lunar wake for the first time on February 13, 2010. We present magnetic field and plasma data of this event and results of 3D hybrid simulations. As the solar wind magnetic field was highly dynamic during the passage, a simulation with stationary solar wind input cannot distinguish whether distortions were caused by these solar wind variations or by the lunar wake; therefore, a dynamic real-time simulation of the flyby has been performed. The input values of this simulation are taken from NASA OMNI data and adapted to the P1 data, resulting in a good agreement between simulation and measurements. Combined with the stationary simulation showing non-transient lunar wake structures, a separation of solar wind and wake effects is achieved. An anisotropy in the magnitude of the plasma bulk flow velocity caused by a non-vanishing magnetic field component parallel to the solar wind flow and perturbations created by counterstreaming ions in the lunar wake are observed in data and simulations. The simulations help to interpret the data granting us the opportunity to examine the entire lunar plasma environment and, thus, extending the possibilities of measurements alone: A comparison of a simulation cross section to theoretical predictions of MHD wave propagation shows that all three basic MHD modes are present in the lunar wake and that their expansion governs the lunar wake refilling process.

  6. 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

  7. 3D Interdigital Au/MnO2 /Au Stacked Hybrid Electrodes for On-Chip Microsupercapacitors.

    PubMed

    Hu, Haibo; Pei, Zhibin; Fan, Hongjin; Ye, Changhui

    2016-06-01

    On-chip microsupercapacitors (MSCs) have application in powering microelectronic devices. Most of previous MSCs are made from carbon materials, which have high power but low energy density. In this work, 3D interdigital Au/MnO2 /Au stacked MSCs have been fabricated based on laser printed flexible templates. This vertical-stacked electrode configuration can effectively increase the contact area between MnO2 active layer and Au conductive layer, and thus improve the electron transport and electrolyte ion diffusion, resulting in enhanced pseudocapacitive performance of MnO2 . The stacked electrode can achieve an areal capacitance up to 11.9 mF cm(-2) . Flexible and all-solid-state MSCs are assembled based on the sandwich hybrid electrodes and PVA/LiClO4 gel electrolyte and show outstanding high-rate capacity and mechanical flexibility. The laser printing technique in this work combined with the physical sputtering and electrodeposition allows fabrication of MSC array with random sizes and patterns, making them promising power sources for small-scale flexible microelectronic energy storage systems (e.g., next-generation smart phones). PMID:27116677

  8. 3D Interdigital Au/MnO2 /Au Stacked Hybrid Electrodes for On-Chip Microsupercapacitors.

    PubMed

    Hu, Haibo; Pei, Zhibin; Fan, Hongjin; Ye, Changhui

    2016-06-01

    On-chip microsupercapacitors (MSCs) have application in powering microelectronic devices. Most of previous MSCs are made from carbon materials, which have high power but low energy density. In this work, 3D interdigital Au/MnO2 /Au stacked MSCs have been fabricated based on laser printed flexible templates. This vertical-stacked electrode configuration can effectively increase the contact area between MnO2 active layer and Au conductive layer, and thus improve the electron transport and electrolyte ion diffusion, resulting in enhanced pseudocapacitive performance of MnO2 . The stacked electrode can achieve an areal capacitance up to 11.9 mF cm(-2) . Flexible and all-solid-state MSCs are assembled based on the sandwich hybrid electrodes and PVA/LiClO4 gel electrolyte and show outstanding high-rate capacity and mechanical flexibility. The laser printing technique in this work combined with the physical sputtering and electrodeposition allows fabrication of MSC array with random sizes and patterns, making them promising power sources for small-scale flexible microelectronic energy storage systems (e.g., next-generation smart phones).

  9. MERIDIONAL CIRCULATION DYNAMICS FROM 3D MAGNETOHYDRODYNAMIC GLOBAL SIMULATIONS OF SOLAR CONVECTION

    SciTech Connect

    Passos, Dário; Charbonneau, Paul; Miesch, Mark

    2015-02-10

    The form of solar meridional circulation is a very important ingredient for mean field flux transport dynamo models. However, a shroud of mystery still surrounds this large-scale flow, given that its measurement using current helioseismic techniques is challenging. In this work, we use results from three-dimensional global simulations of solar convection to infer the dynamical behavior of the established meridional circulation. We make a direct comparison between the meridional circulation that arises in these simulations and the latest observations. Based on our results, we argue that there should be an equatorward flow at the base of the convection zone at mid-latitudes, below the current maximum depth helioseismic measures can probe (0.75 R{sub ⊙}). We also provide physical arguments to justify this behavior. The simulations indicate that the meridional circulation undergoes substantial changes in morphology as the magnetic cycle unfolds. We close by discussing the importance of these dynamical changes for current methods of observation which involve long averaging periods of helioseismic data. Also noteworthy is the fact that these topological changes indicate a rich interaction between magnetic fields and plasma flows, which challenges the ubiquitous kinematic approach used in the vast majority of mean field dynamo simulations.

  10. A global 3D P-velocity model of the Earth's crust and mantle for improved event location.

    SciTech Connect

    Ballard, Sanford; Encarnacao, Andre Villanova; Begnaud, Michael A.; Rowe, Charlotte A.; Lewis, Jennifer E.; Young, Christopher John; Chang, Marcus C.; Hipp, James Richard

    2010-04-01

    To test the hypothesis that high quality 3D Earth models will produce seismic event locations which are more accurate and more precise, we are developing a global 3D P wave velocity model of the Earth's crust and mantle using seismic tomography. In this paper, we present the most recent version of our model, SALSA3D (SAndia LoS Alamos) version 1.4, and demonstrate its ability to reduce mislocations for a large set of realizations derived from a carefully chosen set of globally-distributed ground truth events. Our model is derived from the latest version of the Ground Truth (GT) catalog of P and Pn travel time picks assembled by Los Alamos National Laboratory. To prevent over-weighting due to ray path redundancy and to reduce the computational burden, we cluster rays to produce representative rays. Reduction in the total number of ray paths is > 55%. The model is represented using the triangular tessellation system described by Ballard et al. (2009), which incorporates variable resolution in both the geographic and radial dimensions. For our starting model, we use a simplified two layer crustal model derived from the Crust 2.0 model over a uniform AK135 mantle. Sufficient damping is used to reduce velocity adjustments so that ray path changes between iterations are small. We obtain proper model smoothness by using progressive grid refinement, refining the grid only around areas with significant velocity changes from the starting model. At each grid refinement level except the last one we limit the number of iterations to prevent convergence thereby preserving aspects of broad features resolved at coarser resolutions. Our approach produces a smooth, multi-resolution model with node density appropriate to both ray coverage and the velocity gradients required by the data. This scheme is computationally expensive, so we use a distributed computing framework based on the Java Parallel Processing Framework, providing us with {approx}400 processors. Resolution of our model

  11. 3D Global Climate Modelling of the environmental effect of meteoritic impacts on Early Mars

    NASA Astrophysics Data System (ADS)

    Turbet, Martin; Forget, Francois; Gillmann, Cedric; Karatekin, Ozgur; Svetsov, Vladimir; Popova, Olga; Wallemacq, Quentin

    2016-10-01

    There are now robust evidences that liquid water flowed on ancient Mars: dry river beds and lakes, hydrated sedimentary minerals and high erosion rates. Climate models that consider only CO2/H2O as greenhouse gases have been unable yet to produce warm climates suitable for liquid water on Early Mars, given the lower solar luminosity at that time. It has been suggested that the warm conditions required to explain the formation of the 3.8 Gyrs old valley networks could have been transient and produced in response to the meteoritic impacts that occured during the contemporaneous Late Heavy Bombardment (LHB). This scenario is appealing because, in a predominately cold climate, the ice tends to accumulate preferentially in the regions where the rivers were sculpted ('Icy Highlands' scenario). This would be a very efficient mechanism of recharge of the valley network water sources between two impact-induced melting events.Using the LMD Global Climate Model (LMD-GCM) designed for flexible (from cold & dry to warm & wet) conditions, we explored the environmental effect of LHB impact events of various sizes on Early Mars. Our main result is that, whatever the initial impact-induced temperatures and water vapor content injected, warm climates cannot be stable and are in fact short-lived (lifetime of ~ 5 martian years/bar of H2O injected). Moreover, we will give preliminar estimates of the amount of rainfall/snowmelt that can be produced after impact events depending on their size, following three different approaches:1) For large impact events (Dimpactor < 50km, N ~ 40) we initialize the LMD-GCM with warm/moist conditions prescribed with simple scaling laws and assuming energy conservation.2) For moderate-size events (5km < Dimpactor < 50km, N ~ 3x103) we use the SOVA hydrocode for short-term modelling of impact cratering. It provides us with post-impact temperature fields, injection of volatiles, ejecta and dust distribution that serve as input for the LMD-GCM.3

  12. Saturn's Magnetosphere Interaction with Titan for T9 Encounter: 3D Hybrid Modeling and Comparison with CAPS Observations

    NASA Technical Reports Server (NTRS)

    Lipatov, A. S.; Sittler, E. C., Jr.; Hartle, R. E.; Cooper, J. F.; Simpson, D. G.

    2011-01-01

    Global dynamics of ionized and neutral gases in the environment of Titan plays an important role in the interaction of Saturn s magnetosphere with Titan. Several hybrid simulations of this problem have already been done (Brecht et al., 2000; Kallio et al., 2004; Modolo et al., 2007a; Simon et al., 2007a, 2007b; Modolo and Chanteur, 2008). Observational data from CAPS for the T9 encounter (Sittler et al., 2009) indicates an absence of O(+) heavy ions in the upstream that change the models of interaction which were discussed in current publications (Kallio et al., 2004; Modolo et al., 2007a; Simon et al., 2007a, 2007b; Ma et al., 2007; Szego et al., 2007). Further analysis of the CAPS data shows very low density or even an absence of H(+) ions in upstream. In this paper we discuss two models of the interaction of Saturn s magnetosphere with Titan: (A) high density of H(+) ions in the upstream flow (0.1/cu cm), and (B) low density of H(+) ions in the upstream flow (0.02/cu cm). The hybrid model employs a fluid description for electrons and neutrals, whereas a particle approach is used for ions. We also take into account charge-exchange and photoionization processes and solve self-consistently for electric and magnetic fields. The model atmosphere includes exospheric H(+), H(2+), N(2+)and CH(4+) pickup ion production as well as an immobile background ionosphere and a shell distribution for active ionospheric ions (M(sub i)=28 amu). The hybrid model allows us to account for the realistic anisotropic ion velocity distribution that cannot be done in fluid simulations with isotropic temperatures. Our simulation shows an asymmetry of the ion density distribution and the magnetic field, including the formation of Alfven wing-like structures. The results of the ion dynamics in Titan s environment are compared with Cassini T9 encounter data (CAPS).

  13. A comparison study of atlas-based 3D cardiac MRI segmentation: global versus global and local transformations

    NASA Astrophysics Data System (ADS)

    Daryanani, Aditya; Dangi, Shusil; Ben-Zikri, Yehuda Kfir; Linte, Cristian A.

    2016-03-01

    Magnetic Resonance Imaging (MRI) is a standard-of-care imaging modality for cardiac function assessment and guidance of cardiac interventions thanks to its high image quality and lack of exposure to ionizing radiation. Cardiac health parameters such as left ventricular volume, ejection fraction, myocardial mass, thickness, and strain can be assessed by segmenting the heart from cardiac MRI images. Furthermore, the segmented pre-operative anatomical heart models can be used to precisely identify regions of interest to be treated during minimally invasive therapy. Hence, the use of accurate and computationally efficient segmentation techniques is critical, especially for intra-procedural guidance applications that rely on the peri-operative segmentation of subject-specific datasets without delaying the procedure workflow. Atlas-based segmentation incorporates prior knowledge of the anatomy of interest from expertly annotated image datasets. Typically, the ground truth atlas label is propagated to a test image using a combination of global and local registration. The high computational cost of non-rigid registration motivated us to obtain an initial segmentation using global transformations based on an atlas of the left ventricle from a population of patient MRI images and refine it using well developed technique based on graph cuts. Here we quantitatively compare the segmentations obtained from the global and global plus local atlases and refined using graph cut-based techniques with the expert segmentations according to several similarity metrics, including Dice correlation coefficient, Jaccard coefficient, Hausdorff distance, and Mean absolute distance error.

  14. A 3D hybrid praseodymium-antimony-oxochloride compound: single-crystal-to-single-crystal transformation and photocatalytic properties.

    PubMed

    Zou, Guo-Dong; Zhang, Gui-Gang; Hu, Bing; Li, Jian-Rong; Feng, Mei-Ling; Wang, Xin-Chen; Huang, Xiao-Ying

    2013-11-01

    A 3D organic-inorganic hybrid compound, (2-MepyH)3[{Fe(1,10-phen)3}3][{Pr4Sb12O18(OH)Cl(11.5)}(TDC)(4.5)({Pr4Sb12O18(OH)Cl(9.5)} Cl)]·3(2-Mepy)·28H2O (1; 2-Mepy=2-methylpyridine, 1,10-phen=1,10-phenanthroline, H2TDC=thiophene-2,5-dicarboxylic acid), was hydrothermally synthesized and structurally characterized. Unusually, two kinds of high-nuclearity clusters, namely [(Pr4Sb12O18(OH)Cl11)(COO)5](5-) and [(Pr4Sb12O18(OH)Cl9)Cl(COO)5](4-), coexist in the structure of compound 1; two of the latter clusters are doubly bridged by two μ2-Cl(-) moieties to form a new centrosymmetric dimeric cluster. An unprecedented spontaneous and reversible single-crystal-to-single-crystal transformation was observed, which simultaneously involved a notable organic-ligand movement between the metal ions and an alteration of the bridging ion in the dimeric cluster, induced by guest-release/re-adsorption, thereby giving rise to the interconversion between compound 1 and the compound (2-MepyH)3[{Fe(1,10-phen)3}3][{Pr4Sb12O18(OH)Cl(11.5)}(TDC)4({Pr4Sb12O18Cl(10.5)(TDC)(0.5)(H2O)(1.5)}O(0.5))]·25H2O (1'). The mechanism of this transformation has also been discussed in great detail. Photocatalytic H2-evolution activity was observed for compound 1' under UV light with Pt as a co-catalyst and MeOH as a sacrificial electron donor.

  15. A 3D hybrid praseodymium-antimony-oxochloride compound: single-crystal-to-single-crystal transformation and photocatalytic properties.

    PubMed

    Zou, Guo-Dong; Zhang, Gui-Gang; Hu, Bing; Li, Jian-Rong; Feng, Mei-Ling; Wang, Xin-Chen; Huang, Xiao-Ying

    2013-11-01

    A 3D organic-inorganic hybrid compound, (2-MepyH)3[{Fe(1,10-phen)3}3][{Pr4Sb12O18(OH)Cl(11.5)}(TDC)(4.5)({Pr4Sb12O18(OH)Cl(9.5)} Cl)]·3(2-Mepy)·28H2O (1; 2-Mepy=2-methylpyridine, 1,10-phen=1,10-phenanthroline, H2TDC=thiophene-2,5-dicarboxylic acid), was hydrothermally synthesized and structurally characterized. Unusually, two kinds of high-nuclearity clusters, namely [(Pr4Sb12O18(OH)Cl11)(COO)5](5-) and [(Pr4Sb12O18(OH)Cl9)Cl(COO)5](4-), coexist in the structure of compound 1; two of the latter clusters are doubly bridged by two μ2-Cl(-) moieties to form a new centrosymmetric dimeric cluster. An unprecedented spontaneous and reversible single-crystal-to-single-crystal transformation was observed, which simultaneously involved a notable organic-ligand movement between the metal ions and an alteration of the bridging ion in the dimeric cluster, induced by guest-release/re-adsorption, thereby giving rise to the interconversion between compound 1 and the compound (2-MepyH)3[{Fe(1,10-phen)3}3][{Pr4Sb12O18(OH)Cl(11.5)}(TDC)4({Pr4Sb12O18Cl(10.5)(TDC)(0.5)(H2O)(1.5)}O(0.5))]·25H2O (1'). The mechanism of this transformation has also been discussed in great detail. Photocatalytic H2-evolution activity was observed for compound 1' under UV light with Pt as a co-catalyst and MeOH as a sacrificial electron donor. PMID:24114981

  16. Novel assembly and electrochemical properties of anatase TiO2-graphene aerogel 3D hybrids as lithium-ion battery anodes

    NASA Astrophysics Data System (ADS)

    Zhang, Jingjie; Zhou, Yizhuo; Zheng, Guangping; Huang, Qiuying; Zheng, Xiucheng; Liu, Pu; Zhang, Jianmin; Guan, Xinxin

    2016-10-01

    TiO2-graphene aerogel (TiO2-GA) 3D hybrids were directly assembled via a one-pot hydrothermal process followed by freeze-drying without using any structure-directing agent. The hybrids with a hierarchical structure exhibited large surface area (SBET = 283.6 m2 g-1) and high pore volume (Vp = 0.278 cm3 g-1), in which the ultradispersed TiO2 nanoparticles were in a single crystal phase of anatase. When used as the anodes for lithium ion battery, the TiO2-GA hybrids exhibited higher reversible capacity, more stable cycling performance and better rate-capability than TiO2 ascribed to the unique 3D nanoporous structure and the synergistic interaction of GA and TiO2.

  17. Global well-posedness to the 3-D incompressible inhomogeneous Navier-Stokes equations with a class of large velocity

    NASA Astrophysics Data System (ADS)

    Zhai, Cuili; Zhang, Ting

    2015-09-01

    In this article, we consider the global well-posedness to the 3-D incompressible inhomogeneous Navier-Stokes equations with a class of large velocity. More precisely, assuming a 0 ∈ B˙ q , 1 /3 q ( R 3 ) and u 0 = ( u0 h , u0 3 ) ∈ B˙ p , 1 - 1 + /3 p ( R 3 ) for p, q ∈ (1, 6) with sup ( /1 p , /1 q ) ≤ /1 3 + inf ( /1 p , /1 q ) , we prove that if C a↑0↑ B˙q1/3 q α (↑u0 3↑ B˙ p , 1 - 1 + /3 p/μ + 1 ) ≤ 1 , /C μ (↑u0 h↑ B˙ p , 1 - 1 + /3 p + ↑u03↑ B˙ p , 1 - 1 + /3 p 1 - α ↑u0h↑ B˙ p , 1 - 1 + /3 p α) ≤ 1 , then the system has a unique global solution a ∈ C ˜ ( [ 0 , ∞ ) ; B˙ q , 1 /3 q ( R 3 ) ) , u ∈ C ˜ ( [ 0 , ∞ ) ; B˙ p , 1 - 1 + /3 p ( R 3 ) ) ∩ L 1 ( R + ; B˙ p , 1 1 + /3 p ( R 3 ) ) . It improves the recent result of M. Paicu and P. Zhang [J. Funct. Anal. 262, 3556-3584 (2012)], where the exponent form of the initial smallness condition is replaced by a polynomial form.

  18. Representing surface and subsurface hydrology at hyperresolution for Earth system models: Development of a hybrid 3-D approach

    NASA Astrophysics Data System (ADS)

    Hazenberg, P.; Broxton, P. D.; Brunke, M.; Gochis, D. J.; Lawrence, D. M.; Niu, G. Y.; Pelletier, J. D.; Troch, P. A. A.; Zeng, X.

    2014-12-01

    Traditionally, LSMs for use in Earth system models (ESMs) only account for one-dimensional (1-D) vertical hydrological processes at very coarse resolutions (~100 km). Recently, there has been interest in simulating lateral exchange of surface and subsurface water, as the grid resolution of ESMs increases (currently towards ~20 km) due to advances in computational power.In the current work, we present a new physically-based hydrological model capable of simulating lateral flow at a hyperresolution (1 km pixels) coupled with the vertical soil column of the Community Land Model (CLM), which has a much coarser resolution. Our new approach also uses sub-pixel topographic information to represent small scale lateral-flow processes. As input to our model, we use 1 km data of required surface and subsurface information, such depth to bedrock, hillslope width functions, fractional coverage of hillslopes/wetlands/riparian zones within each 1 km pixel, and a river network. Such data are largely derived from higher-resolution (30 m) topographic data, and will be made available to the community as global products.We have tested our model against measurements over a well instrumented, artificial hillslope at the University of Arizona's Biosphere 2 and found that both our approach and a full 3-D physically-based hydrological model can realistically simulate hydrological states and fluxes. However, computationally, our approach is 2 - 3 orders of magnitude faster than the latter. We are currently testing it for an ESM grid box that covers much of southeastern New York State, which includes the headwaters of the Delaware River, the Susquehana River, and parts of the Mohawk River Basin. Our approach improves upon the 1-D hydrological representation in CLM by representing the subgrid topographic and geomorphological variability in the grid box. The impact of representing such subgrid variability on surface water and energy fluxes will be discussed in our presentation.

  19. Two highly connected POM-based hybrids varying from 2D to 3D: The use of the isomeric ligands

    SciTech Connect

    Zhang Chunjing; Pang Haijun; Hu Mixia; Li Jia; Chen Yaguang

    2009-07-15

    Through employing two isomeric ligands, isonicotinic acid (HINA) and nicotinic acid (HNA), with different electron delocalization nature, two high-dimensional hybrids based on highly connected alpha-metatungstate clusters, [Na{sub 2}(H{sub 2}O){sub 8}Ag{sub 2}(HINA){sub 3}(INA)][Na(H{sub 2}O){sub 2}Ag{sub 2}(HINA){sub 4}(H{sub 2}W{sub 12}O{sub 40})].2H{sub 2}O (1) and [Na{sub 2}(H{sub 2}O){sub 4}Ag{sub 6}(HNA){sub 2}(NA){sub 2}(H{sub 2}W{sub 12}O{sub 40})].8H{sub 2}O (2), have been conventionally synthesized and structurally characterized. 1 exhibits an unusual 1D-in-2D pseudo-polyrotaxane entangled structure, namely, the 2D sheets [Na(H{sub 2}O){sub 2}Ag{sub 2}(HINA){sub 4}(H{sub 2}W{sub 12}O{sub 40})]{sub n}{sup 3n-} are penetrated by enantiomorphous meso-helical chains [Na{sub 2}(H{sub 2}O){sub 8}Ag{sub 2}(HINA){sub 3}(INA)]{sub n}{sup 3n+}. In the 2D sheets, each [H{sub 2}W{sub 12}O{sub 40}]{sup 6-} cluster is surrounded by six Ag and two Na atoms. 2 exhibits a 3D (4, 6)-net structure with (3{sup 2}6{sup 2}7{sup 2})(3{sup 2}4{sup 4}5{sup 4}6{sup 4}7)(3{sup 2}4{sup 4}6{sup 8}7) topology, in which each [H{sub 2}W{sub 12}O{sub 40}]{sup 6-} cluster is connected with ten Ag atoms. These facts indicate that the isomeric ligands play a key role in the formation of final structures. From 1 to 2, the connection number of the [H{sub 2}W{sub 12}O{sub 40}]{sup 6-} cluster changes from 8 to 10 and the dimensionality increases from 2 to 3. Moreover, 1 and 2 display photoluminescent properties in the blue range at room temperature. - Graphical abstract: Two high-dimensional and highly connected alpha-metatungstate-compounds modified by Ag{sup I}-HINA/HNA TMCs were successful obtained and the effect of isomeric organic ligands on the structures was systematically elucidated.

  20. Hybrid MV-kV 3D respiratory motion tracking during radiation therapy with low imaging dose

    NASA Astrophysics Data System (ADS)

    Yan, Huagang; Li, Haiyun; Liu, Zhixiang; Nath, Ravinder; Liu, Wu

    2012-12-01

    A novel real-time adaptive MV-kV imaging framework for image-guided radiation therapy is developed to reduce the thoracic and abdominal tumor targeting uncertainty caused by respiration-induced intrafraction motion with ultra-low patient imaging dose. In our method, continuous stereoscopic MV-kV imaging is used at the beginning of a radiation therapy delivery for several seconds to measure the implanted marker positions. After this stereoscopic imaging period, the kV imager is switched off except for the times when no fiducial marker is detected in the cine-MV images. The 3D time-varying marker positions are estimated by combining the MV 2D projection data and the motion correlations between directional components of marker motion established from the stereoscopic imaging period and updated afterwards; in particular, the most likely position is assumed to be the position on the projection line that has the shortest distance to the first principal component line segment constructed from previous trajectory points. An adaptive windowed auto-regressive prediction is utilized to predict the marker position a short time later (310 ms and 460 ms in this study) to allow for tracking system latency. To demonstrate the feasibility and evaluate the accuracy of the proposed method, computer simulations were performed for both arc and fixed-gantry deliveries using 66 h of retrospective tumor motion data from 42 patients treated for thoracic or abdominal cancers. The simulations reveal that using our hybrid approach, a smaller than 1.2 mm or 1.5 mm root-mean-square tracking error can be achieved at a system latency of 310 ms or 460 ms, respectively. Because the kV imaging is only used for a short period of time in our method, extra patient imaging dose can be reduced by an order of magnitude compared to continuous MV-kV imaging, while the clinical tumor targeting accuracy for thoracic or abdominal cancers is maintained. Furthermore, no additional hardware is required with the

  1. Combination of spaceborne sensor(s) and 3-D aerosol models to assess global daily near-surface air quality

    NASA Astrophysics Data System (ADS)

    Kacenelenbogen, M.; Redemann, J.; Russell, P. B.

    2009-12-01

    Aerosol Particulate Matter (PM), measured by ground-based monitoring stations, is used as a standard by the EPA (Environmental Protection Agency) to evaluate daily air quality. PM monitoring is particularly important for human health protection because the exposure to suspended particles can contribute, among others, to lung and respiratory diseases and even premature death. However, most of the PM monitoring stations are located close to cities, leaving large areas without any operational data. Satellite remote sensing is well suited for a global coverage of the aerosol load and can provide an independent and supplemental data source to in situ monitoring. Nevertheless, PM at the ground cannot easily be determined from satellite AOD (Aerosol Optical Depth) without additional information on the optical/microphysical properties and vertical distribution of the aerosols. The objective of this study is to explore the efficacy and accuracy of combining a 3-D aerosol transport model and satellite remote sensing as a cost-effective approach for estimating ground-level PM on a global and daily basis. The estimation of the near-surface PM will use the vertical distribution (and, if possible, the physicochemical properties) of the aerosols inferred from a transport model and the measured total load of particles in the atmospheric column retrieved by satellite sensor(s). The first step is to select a chemical transport model (CTM) that provides “good” simulated aerosol vertical profiles. A few global (e.g., WRF-Chem-GOCART) or regional (e.g., MM5-CMAQ, PM-CAMx) CTM will be compared during selected airborne campaigns like ARCTAS-CARB (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites- California Air Resources Board). The next step will be to devise an algorithm that combines the satellite and model data to infer PM mass estimates at the ground, after evaluating different spaceborne instruments and possible multi-sensor combinations.

  2. 3D porous and ultralight carbon hybrid nanostructure fabricated from carbon foam covered by monolayer of nitrogen-doped carbon nanotubes for high performance supercapacitors

    NASA Astrophysics Data System (ADS)

    He, Shuijian; Hou, Haoqing; Chen, Wei

    2015-04-01

    3D porous and self-supported carbon hybrids are promising electrode materials for supercapacitor application attributed to their prominent properties such as binder-free electrode fabrication process, excellent electric conductivity and high power density etc. We present here a facile chemical vapor deposition method to fabricate a novel 3D flexible carbon hybrid nanostructure by growing a monolayer of nitrogen-doped carbon nanotubes on the skeleton of carbon foam (N-CNTs/CF) with Fe nanoparticle as catalyst. With such 3D porous, flexible and ultralight carbon nanostructure as binder-free electrode material, large surface area is available and fast ionic transport is facilitated. Moreover, the carbon-based network can provide excellent electronic conductivity. The electrochemical studies demonstrate that the supercapacitor constructed from the N-CNTs/CF hybrid exhibit high power density of 69.3 kW kg-1 and good stability with capacitance retention ration above 95% after cycled at 50 A g-1 for 5000 cycles. Therefore, the prepared porous N-CNTs/CF nanostructure is expected to be a type of excellent electrode material for electrical double layer capacitors.

  3. Mapping the 3D distribution of CdSe nanocrystals in highly oriented and nanostructured hybrid P3HT-CdSe films grown by directional epitaxial crystallization.

    PubMed

    Roiban, L; Hartmann, L; Fiore, A; Djurado, D; Chandezon, F; Reiss, P; Legrand, J-F; Doyle, S; Brinkmann, M; Ersen, O

    2012-11-21

    Highly oriented and nanostructured hybrid thin films made of regioregular poly(3-hexylthiophene) and colloidal CdSe nanocrystals are prepared by a zone melting method using epitaxial growth on 1,3,5-trichlorobenzene oriented crystals. The structure of the films has been analyzed by X-ray diffraction using synchrotron radiation, electron diffraction and 3D electron tomography to afford a multi-scale structural and morphological description of the highly structured hybrid films. A quantitative analysis of the reconstructed volumes based on electron tomography is used to establish a 3D map of the distribution of the CdSe nanocrystals in the bulk of the films. In particular, the influence of the P3HT-CdSe ratio on the 3D structure of the hybrid layers has been analyzed. In all cases, a bi-layer structure was observed. It is made of a first layer of pure oriented semi-crystalline P3HT grown epitaxially on the TCB substrate and a second P3HT layer containing CdSe nanocrystals uniformly distributed in the amorphous interlamellar zones of the polymer. The thickness of the P3HT layer containing CdSe nanoparticles increases gradually with increasing content of NCs in the films. A growth model is proposed to explain this original transversal organization of CdSe NCs in the oriented matrix of P3HT.

  4. Global hybrid simulations of the ion foreshock

    NASA Astrophysics Data System (ADS)

    Omidi, N.; Blanco-Cano, X.; Sibeck, D.; Russell, C.

    2005-12-01

    The ion foreshock is a dynamic region with many linear and nonlinear plasma processes which lead to a variety of observables such as ion beams, ULF waves and cavity structures. Local spacecraft observations and theory/simulation studies have investigated many individual processes in the foreshock. Global hybrid (kinetic ions, fluid electrons) simulations of the bow shock and associated foreshock provide a collective picture of these processes and how they interact together. These simulations also allow us to understand how the structure of the foreshock and the processes contained in it vary as a function of solar wind conditions such as, the direction of the interplanetary magnetic field (IMF). In this talk, results from global hybrid simulations of the ion foreshock, for northward, southward, radial and intermediate IMF directions are presented and the differences and similarities discussed. Emphasis will be on the origin, evolution and consequences of 30 second sinusoidal waves and shocklets, various ion beam populations, as well as, foreshock cavities. In addition, issues regarding the coupling between the foreshock, bow shock, magnetosheath and the magnetopause are discussed. This coupling has direct impact on the nature of solar wind magnetosphere interaction and involves processes propagating in both directions. Namely, it is demonstrated that foreshock phenomenon influence processes at the magnetopause and visa-versa where reconnection at the magnetopause directly modifies ion foreshock structure and dynamics.

  5. Towards 3D multi-scale teleseismic and gravity data inversion using hybrid DSM/SPECFEM technique : application to the Pyrenees

    NASA Astrophysics Data System (ADS)

    Martin, Roland; Monteiller, Vadim; Chevrot, Sébastien; Wang, Yi; Komatitsch, Dimitri; Dufréchou, Grégory

    2015-04-01

    We describe here a method of inversion applied to seismic data sets constrained by gravity data at the regional scale. This will allow us to obtain robust models of P and S wave velocities but also of density, providing key constraints on the composition and thermal state of the lithosphere. Our approach relies on teleseimic waves, which illuminate the medium from below. We have developped a hybrid method in which a wave propagation method at the global scale (DSM/Direct solution method) is coupled with a spectral element method at the regional scale (Monteiller et al. 2013). With the spectral element method, we are able to model the 3D wave propagation effects in a computational domain of 400km long x 400km wide and 200 km deep, for an incident teleseismic wavefront introduced at the boundaries of this domain with periods as short as 2 s. The DSM global method allows to compute this incident field for a spherical Earth model. We use a multi-scale joint inversion of both gravity and seismic waveform data, accounting for the long wavelengths of the gravity field taken from a global model. In terms of inversion technique, we have validated an adjoint method for the inversion of seismic waveforms. An optimized BFGS inversion technique is used to minimize the difference between observed and computed full waveforms. The gradient of the misfit function gives the direction over which the model must be perturbed to minimize this difference. At each step of the inversion procedure we choose an optimal step length that accelerates the minimization. This is the crucial ingredient that allows us to build an efficient iterative full waveform inversion. We have extended this method by incorporating gravity data provided by the BGI/Bureau Gravimétrique International into the inversion. If the waveforms allow us to constrain the seismic velocities, they are less sensitive to the structure in density, which gives independent and crucial information to constrain the nature of rocks

  6. Global Hybrid Simulations of Energetic Particle-driven Modes in Toroidal Plasmas

    SciTech Connect

    G.Y. Fu; J. Breslau; E. Fredrickson; W. Park; H.R. Strauss

    2004-12-14

    Global hybrid simulations of energetic particle-driven MHD modes have been carried out for tokamaks and spherical tokamaks using the hybrid code M3D. The numerical results for the National Spherical Tokamak Experiments (NSTX) show that Toroidal Alfven Eigenmodes are excited by beam ions with their frequencies consistent with the experimental observations. Nonlinear simulations indicate that the n=2 mode frequency chirps down as the mode moves out radially. For ITER, it is shown that the alpha-particle effects are strongly stabilizing for internal kink mode when central safety factor q(0) is sufficiently close to unity. However, the elongation of ITER plasma shape reduces the stabilization significantly.

  7. Exploring the diversity of climates on terrestrial exoplanets using a generic 3D Global Climate Model (Invited)

    NASA Astrophysics Data System (ADS)

    Forget, F.; Leconte, J.; Wordsworth, R.; Millour, E.; Charnay, B.

    2013-12-01

    What kind of environment may exist on terrestrial planets around other stars? In spite of the lack of direct observations, it may not be premature to speculate on the possible exoplanetary climates, for instance to optimize future telescopic observations, or to assess the probability of habitable worlds in the galaxy. A first major question is to imagine the possible atmospheric composition surface volatile inventory. This depends on complex processes which are difficult to model: origins of volatile, atmospheric escape, geochemistry, long-term photochemistry. However, assuming that the atmosphere is known, the possible climates on a given planet around a given star can be explored using 3D Global Climate Models (GCMs) analogous to the ones developed to simulate the Earth climate as well as the other telluric atmospheres in the solar system. Our experience with the Earth, Mars, Titan and Venus suggests that relatively complete and realistic climate simulators can be developed by combining a few components like a dynamical core, a radiative transfer solver, a parametrisation of subgrid- scale turbulence and convection, a thermal ground model, and a volatile phase change code. Solar system GCMs successes and failure also teach us that when modeling climate systems which are poorly observed, it is necessary to carefully explore the sensitivity of the modeled system to key parameters, in order to 'bracket' the reality We will present several examples of studies recently performed using a 'generic' Global Climate Model that we have developed in the past few years, in particular to better understand the processes which controls the stability of liquid water on a planetary surface and its habitability. Climate models confirm that planetary climates primarily depends on 1) The atmospheric composition and mass and the surface volatile inventory 2) The incident stellar flux 3) The tidal evolution of the planetary spin, which can notably lock a planet with a permanent night

  8. Warps, bending and density waves excited by rotating magnetized stars: results of global 3D MHD simulations

    NASA Astrophysics Data System (ADS)

    Romanova, M. M.; Ustyugova, G. V.; Koldoba, A. V.; Lovelace, R. V. E.

    2013-03-01

    We report results of the first global three-dimensional (3D) magnetohydrodynamic (MHD) simulations of the waves excited in an accretion disc by a rotating star with a dipole magnetic field misaligned from the star's rotation axis (which is aligned with the disc axis). The main results are the following. (1) If the magnetosphere of the star corotates approximately with the inner disc, then we observe a strong one-armed bending wave (a warp). This warp corotates with the star and has a maximum amplitude between corotation radius and the radius of the vertical resonance. The disc's centre of mass can deviate from the equatorial plane up to the distance of zw ≈ 0.1r. However, the effective height of the warp can be larger, hw ≈ 0.3r, due to the finite thickness of the disc. Stars with a range of misalignment angles excite warps. However, the amplitude of the warps is larger for misalignment angles between 15° and 60°. The location and amplitude of the warp do not depend on viscosity, at least for relatively small values of the standard alpha-parameter, up to 0.08. (2) If the magnetosphere rotates slower than the inner disc, then a bending wave is excited at the disc-magnetosphere boundary, but does not form a large-scale warp. Instead, persistent, high-frequency oscillations become strong at the inner region of the disc. These are (a) trapped density waves which form inside the radius where the disc angular velocity has a maximum, and (b) inner bending waves which appear in the case of accretion through magnetic Rayleigh-Taylor instability. These two types of waves are connected with the inner disc and their frequencies will vary with accretion rate. Bending oscillations at lower frequencies are also excited including global oscillations of the disc. In cases where the simulation region is small, slowly precessing warp forms with the maximum amplitude at the vertical resonance. The present simulations are applicable to young stars, cataclysmic variables and

  9. Changes in dissolved iron deposition to the oceans driven by human activity: a 3-D global modelling study

    NASA Astrophysics Data System (ADS)

    Myriokefalitakis, S.; Daskalakis, N.; Mihalopoulos, N.; Baker, A. R.; Nenes, A.; Kanakidou, M.

    2015-03-01

    The global atmospheric iron (Fe) cycle is parameterized in the global 3-D chemical transport model TM4-ECPL to simulate the proton- and the organic ligand-promoted mineral Fe dissolution as well as the aqueous-phase photochemical reactions between the oxidative states of Fe(III/II). Primary emissions of total (TFe) and dissolved (DFe) Fe associated with dust and combustion processes are also taken into account. TFe emissions are calculated to amount to ~35 Tg Fe yr-1. The model reasonably simulates the available Fe observations, supporting the reliability of the results of this study. Accounting for proton- and organic ligand-promoted Fe-dissolution in present-day TM4-ECPL simulations, the total Fe-dissolution is calculated to be ~0.163 Tg Fe yr-1 that accounts for up to ~50% of the calculated total DFe emissions. The atmospheric burden of DFe is calculated to be ~0.012 Tg Fe. DFe deposition presents strong spatial and temporal variability with an annual deposition flux ~0.489 Tg Fe yr-1 from which about 25% (~0.124 Tg Fe yr-1) are deposited over the ocean. The impact of air-quality on Fe deposition is studied by performing sensitivity simulations using preindustrial (year 1850), present (year 2008) and future (year 2100) emission scenarios. These simulations indicate that an increase (~2 times) in Fe-dissolution may have occurred in the past 150 years due to increasing anthropogenic emissions and thus atmospheric acidity. On the opposite, a decrease (~2 times) of Fe-dissolution is projected for near future, since atmospheric acidity is expected to be lower than present-day due to air-quality regulations of anthropogenic emissions. The organic ligand contribution to Fe dissolution shows inverse relationship to the atmospheric acidity thus its importance has decreased since the preindustrial period but is projected to increase in the future. The calculated changes also show that the atmospheric DFe supply to High-Nutrient-Low-Chlorophyll oceanic areas (HNLC

  10. Modelling of Criegee Intermediates using the 3-D global model, STOCHEM-CRI and investigating their global impacts on Secondary Organic Aerosol formation

    NASA Astrophysics Data System (ADS)

    Khan, M. Anwar H.; Cooke, Michael; Utembe, Steve; Archibald, Alexander; Derwent, Richard; Jenkin, Mike; Lyons, Kyle; Kent, Adam; Percival, Carl; Shallcross, Dudley E.

    2016-04-01

    Gas phase reactions of ozone with unsaturated compounds form stabilized Criegee intermediates (sCI) which play an important role in controlling the budgets of many tropospheric species including OH, organic acids and secondary organic aerosols (SOA). Recently sCI has been proposed to play a significant role in atmospheric sulfate and nitrate chemistry by forming sulfuric acid (promoter of aerosol formation) and nitrate radical (a powerful oxidizing agent). sCI can also undergo association reactions with water, alcohols, and carboxylic acids to form hydroperoxides and with aldehydes and ketones to form secondary ozonides. The products from these reactions are low volatility compounds which can contribute to the formation of SOA. The importance of plant emitted alkenes (isoprene, monoterpenes, sesquiterpenes) in the production of SOA through sCI formation have already been investigated in laboratory studies. However, the SOA formation from these reactions are absent in current global models. Thus, the formation of SOA has been incorporated in the global model, STOCHEM-CRI, a 3-D global chemistry transport model and the role of CI chemistry in controlling atmospheric composition and climate, and the influence of water vapor has been discussed in the study.

  11. Changes in dissolved iron deposition to the oceans driven by human activity: a 3-D global modelling study

    NASA Astrophysics Data System (ADS)

    Myriokefalitakis, S.; Daskalakis, N.; Mihalopoulos, N.; Baker, A. R.; Nenes, A.; Kanakidou, M.

    2015-07-01

    The global atmospheric iron (Fe) cycle is parameterized in the global 3-D chemical transport model TM4-ECPL to simulate the proton- and the organic ligand-promoted mineral-Fe dissolution as well as the aqueous-phase photochemical reactions between the oxidative states of Fe (III/II). Primary emissions of total (TFe) and dissolved (DFe) Fe associated with dust and combustion processes are also taken into account, with TFe mineral emissions calculated to amount to ~ 35 Tg-Fe yr-1 and TFe emissions from combustion sources of ~ 2 Tg-Fe yr-1. The model reasonably simulates the available Fe observations, supporting the reliability of the results of this study. Proton- and organic ligand-promoted Fe dissolution in present-day TM4-ECPL simulations is calculated to be ~ 0.175 Tg-Fe yr-1, approximately half of the calculated total primary DFe emissions from mineral and combustion sources in the model (~ 0.322 Tg-Fe yr-1). The atmospheric burden of DFe is calculated to be ~ 0.024 Tg-Fe. DFe deposition presents strong spatial and temporal variability with an annual flux of ~ 0.496 Tg-Fe yr-1, from which about 40 % (~ 0.191 Tg-Fe yr-1) is deposited over the ocean. The impact of air quality on Fe deposition is studied by performing sensitivity simulations using preindustrial (year 1850), present (year 2008) and future (year 2100) emission scenarios. These simulations indicate that about a 3 times increase in Fe dissolution may have occurred in the past 150 years due to increasing anthropogenic emissions and thus atmospheric acidity. Air-quality regulations of anthropogenic emissions are projected to decrease atmospheric acidity in the near future, reducing to about half the dust-Fe dissolution relative to the present day. The organic ligand contribution to Fe dissolution shows an inverse relationship to the atmospheric acidity, thus its importance has decreased since the preindustrial period but is projected to increase in the future. The calculated changes also show that the

  12. The hybridizations of cobalt 3 d bands with the electron band structure of the graphene/cobalt interface on a tungsten substrate

    NASA Astrophysics Data System (ADS)

    Hwang, Jinwoong; Hwang, Choongyu; Chung, Nak-Kwan; N'Diaye, A. D.; Schmid, A. K.; Denlinger, Jonathan

    2016-08-01

    The interface between graphene and a ferromagnetic substrate has attracted recent research interests due to its potential for spintronic applications. We report an angle-resolved photoemission spectroscopy study on the interface between graphene and cobalt epitaxially grown on a tungsten substrate. We find that the electron band structure of the interface exhibits clear discontinuities at the crossing points with cobalt 3 d bands. These observations indicate strong hybridizations between the electronic states in the interface and provide an important clue to understand the intriguing electromagnetic properties of the graphene/ferromagnet interface.

  13. Ideal and non-ideal MHD regimes of wire array implosion obtained in 3D hybrid simulations and observed during experiments at NTF.

    SciTech Connect

    Sotnikov, Vladimir Isaakovich; Fiala, V.; Oliver, Bryan Velten; Ivanov, Vladimir V.; LePell, Paul David; Fedin, Dmitry; Mehlhorn, Thomas Alan; Kantsyrev, Victor Leonidovich; Coverdale, Christine Anne; Travnicek, P.; Hellinger, P.; Deeney, Christopher; Jones, Brent Manley; Safronova, Alla S.; Leboeuf, J. N.; Cowan, Thomas E.

    2004-11-01

    Recent 3D hybrid simulation of a plasma current-carrying column revealed two regimes of sausage and kink instability development. In the first regime, with small Hall parameter, development of instabilities leads to appearance of large-scale axial perturbations and eventually to the bending of the plasma column. In the second regime, with five times larger Hall parameter, small-scale perturbations dominated and no bending of the plasma column was observed. Simulation results are compared to recent experimental data, including laser probing, x-ray spectroscopy and time-gated x-ray imaging during wire array implosions at NTF.

  14. Strong and fast-recovery organic/inorganic hybrid AuNPs-supramolecular gels based on loofah-like 3D networks.

    PubMed

    He, Huiwen; Chen, Si; Tong, Xiaoqian; Chen, Yining; Wu, Bozhen; Ma, Meng; Wang, Xiaosong; Wang, Xu

    2016-01-21

    Super strong and fast-recovery organic/inorganic hybrid gold nanoparticle (AuNPs)-supramolecular gels based on a three-dimensional loofah-like nanoscale network self-assembled by polyhedral oligomeric silsesquioxane (POSS) core supramolecular gelators are reported for the first time. Two series of POSS core organic/inorganic hybrid gelators, POSS-BOC-l-Homophenylalanine (POSS-Hpy) and POSS-Boc-Cys(Bzl)-OH (POSS-Cys), with two types of peripherals having different abilities for driving the self-assembly of AuNPs in gels were designed and synthesized, both of which self-assembled into three-dimensional loofah-like nanoscale gel networks producing hybrid physical gels with fast-recovery behaviors. The mechanical properties of the resultant hybrid gels were dramatically increased by as much as 100 times in the system of sulfur containing POSS-Cys gelators without destroying the fast-recovery behaviors, with the addition of AuNPs, which had direct interaction with AuNPs to give S-Au non-covalent driving force to lead AuNPs self-assemble onto the 3D loofah-like network nanofibres in the supramolecular hybrid gel system. However, in the POSS-Hpy gelator system without sulfur, no strong interaction with AuNPs existed and the POSS-Hpy nanocomposites showed no clear changes in morphology, thermal stability or rheological properties, confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), tube-inversion and rotational rheometer measurements. This indicated that the organic/inorganic hybrid gelator POSS-Cys could be applied to the formation of soft materials in which AuNPs were self-assembled and closely arranged into three-dimensional nanoscale networks. This hybrid material has great potential for applications in self-recovery, nano- and micron-scale electronic devices, because it has both a large mechanical strength and a fast-recovery capability. PMID:26568047

  15. Facile Self-Cross-Linking Synthesis of 3D Nanoporous Co3O4/Carbon Hybrid Electrode Materials for Supercapacitors.

    PubMed

    Wang, Ning; Liu, Qinglei; Kang, Danmiao; Gu, Jiajun; Zhang, Wang; Zhang, Di

    2016-06-29

    A hybrid electrode material with ultrafine Co3O4 nanoparticles embedded throughout a hierarchically nanoporous graphitic carbon matrix has been obtained via a facile self-cross-linking route. Sodium alginate, a biopolymer with an ability of cross-linking with multivalent cobalt cations to form ordered microcrystalline zones, is used as a carbon source to produce nanoporous carbon frameworks of the hybrids. Ultrafine Co3O4 nanoparticles with tunable particle size (3-30 nm) are in situ grown within the nanoporous graphitic carbon frameworks by a simple carbonization of Co-cross-linked alginate. The obtained hybrid electrodes exhibit high specific capacitance of 645, 548, 486, and 347 F/g at scan rates of 5, 10, 20, and 50 mV/s, respectively, and excellent cycle performance with only 1% fading in capacitance after 10 000 cycles at a high current density of 20 A/g. Such excellent capacitive performance is ascribed to the collaborative contributions of well-dispersed ultrafine Co3O4 nanoparticles and conductive nanoporous carbon frameworks. PMID:27266717

  16. Investigation of the Magnetotail and Inner Magnetosphere with Combined Global Hybrid and CIMI Models

    NASA Astrophysics Data System (ADS)

    Lin, Y.; Wang, X.; Perez, J. D.; Fok, M. C. H.

    2014-12-01

    The interconnection between the Earth's inner and outer magnetospheric regions is calculated by coupling an existing 3-D global hybrid simulation code to an existing ring current and radiation belt code, the Comprehensive Inner Magnetosphere/Ionosphere (CIMI) model. In the hybrid simulation, the global dynamics are driven by the solar wind and a southward IMF, and the simulation domain includes the plasma regions from x=-60RE to +20RE . Evolution of the magnetotail is revealed in the hybrid simulation. The response of the ring current and radiation belts is calculated by coupling the CIMI model to the global hybrid model. The hybrid simulation results provide the CIMI model with the magnetic field and electric potential at the high-latitude ionosphere boundary and plasma density and full ion phase space distribution function at the outer boundary at the equator. Our simulation shows that the ion velocity distributions in the tail are non-Maxwellian, with the existence of multiple ion beams, which have a significant impact on the ring current and the convection electric field. Detailed results will be presented for cases with various IMF and solar wind conditions, and the simulation will be compared with satellite observations.

  17. Construction of a 3D rGO-collagen hybrid scaffold for enhancement of the neural differentiation of mesenchymal stem cells

    NASA Astrophysics Data System (ADS)

    Guo, Weibo; Wang, Shu; Yu, Xin; Qiu, Jichuan; Li, Jianhua; Tang, Wei; Li, Zhou; Mou, Xiaoning; Liu, Hong; Wang, Zhonglin

    2016-01-01

    The cell-material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold because the surface of the scaffold can determine the fate of stem cells. A conductive surface is required for a scaffold to direct stem cells toward neural differentiation. However, most conductive polymers are toxic and not amenable to biological degradation, which restricts the design of neural tissue engineering scaffolds. In this study, we used a bioactive three-dimensional (3D) porcine acellular dermal matrix (PADM), which is mainly composed of type I collagen, as a basic material and successfully assembled a layer of reduced graphene oxide (rGO) nanosheets on the surface of the PADM channels to obtain a porous 3D, biodegradable, conductive and biocompatible PADM-rGO hybrid neural tissue engineering scaffold. Compared with the PADM scaffold, assembling the rGO into the scaffold did not induce a significant change in the microstructure but endowed the PADM-rGO hybrid scaffold with good conductivity. A comparison of the neural differentiation of rat bone-marrow-derived mesenchymal stem cells (MSCs) was performed by culturing the MSCs on PADM and PADM-rGO scaffolds in neuronal culture medium, followed by the determination of gene expression and immunofluorescence staining. The results of both the gene expression and protein level assessments suggest that the rGO-assembled PADM scaffold may promote the differentiation of MSCs into neuronal cells with higher protein and gene expression levels after 7 days under neural differentiation conditions. This study demonstrated that the PADM-rGO hybrid scaffold is a promising scaffold for neural tissue engineering; this scaffold can not only support the growth of MSCs at a high proliferation rate but also enhance the differentiation of MSCs into neural cells.The cell-material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold

  18. Ectopic bone formation by 3D porous calcium phosphate-Ti6Al4V hybrids produced by perfusion electrodeposition.

    PubMed

    Chai, Yoke Chin; Kerckhofs, Greet; Roberts, Scott J; Van Bael, Simon; Schepers, Evert; Vleugels, Jozef; Luyten, Frank P; Schrooten, Jan

    2012-06-01

    Successful clinical repair of non-healing skeletal defects requires the use of bone substitutes with robust bone inductivity and excellent biomechanical stability. Thus, three-dimensionally functionalised porous calcium phosphate-Ti6Al4V (CaP-Ti) hybrids were produced by perfusion electrodeposition, and the in vitro and in vivo biological performances were evaluated using human periosteum derived cells (hPDCs). By applying various current densities at the optimised deposition conditions, CaP coatings with sub-micrometer to nano-scale porous crystalline structures and different ion dissolution kinetics were deposited on the porous Ti6Al4V scaffolds. These distinctive physicochemical properties caused a significant impact on in vitro proliferation, osteogenic differentiation, and matrix mineralisation of hPDCs. This includes a potential role of hPDCs in mediating osteoclastogenesis for the resorption of CaP coatings, as indicated by a significant down-regulation of osteoprotegerin (OPG) gene expression and by the histological observation of abundant multi-nucleated giant cells near to the coatings. By subcutaneous implantation, the produced hybrids induced ectopic bone formation, which was highly dependent on the physicochemical properties of the CaP coating (including the Ca(2+) dissolution kinetics and coating surface topography), in a cell density-dependent manner. This study provided further insight on stem cell-CaP biomaterial interactions, and the feasibility to produced bone reparative units that are predictively osteoinductive in vivo by perfusion electrodeposition technology.

  19. 3D electrostatic gyrokinetic electron and fully kinetic ion simulation of lower-hybrid drift instability of Harris current sheet

    DOE PAGES

    Wang, Zhenyu; Lin, Yu; Wang, Xueyi; Tummel, Kurt; Chen, Liu

    2016-07-07

    The eigenmode stability properties of three-dimensional lower-hybrid-drift-instabilities (LHDI) in a Harris current sheet with a small but finite guide magnetic field have been systematically studied by employing the gyrokinetic electron and fully kinetic ion (GeFi) particle-in-cell (PIC) simulation model with a realistic ion-to-electron mass ratio mi/me. In contrast to the fully kinetic PIC simulation scheme, the fast electron cyclotron motion and plasma oscillations are systematically removed in the GeFi model, and hence one can employ the realistic mi/me. The GeFi simulations are benchmarked against and show excellent agreement with both the fully kinetic PIC simulation and the analytical eigenmode theory. Our studies indicate that, for small wavenumbers, ky, along the current direction, the most unstable eigenmodes are peaked at the location wheremore » $$\\vec{k}$$• $$\\vec{B}$$ =0, consistent with previous analytical and simulation studies. Here, $$\\vec{B}$$ is the equilibrium magnetic field and $$\\vec{k}$$ is the wavevector perpendicular to the nonuniformity direction. As ky increases, however, the most unstable eigenmodes are found to be peaked at $$\\vec{k}$$ •$$\\vec{B}$$ ≠0. Additionally, the simulation results indicate that varying mi/me, the current sheet width, and the guide magnetic field can affect the stability of LHDI. Simulations with the varying mass ratio confirm the lower hybrid frequency and wave number scalings.« less

  20. 3D electrostatic gyrokinetic electron and fully kinetic ion simulation of lower-hybrid drift instability of Harris current sheet

    NASA Astrophysics Data System (ADS)

    Wang, Zhenyu; Lin, Yu; Wang, Xueyi; Tummel, Kurt; Chen, Liu

    2016-07-01

    The eigenmode stability properties of three-dimensional lower-hybrid-drift-instabilities (LHDI) in a Harris current sheet with a small but finite guide magnetic field have been systematically studied by employing the gyrokinetic electron and fully kinetic ion (GeFi) particle-in-cell (PIC) simulation model with a realistic ion-to-electron mass ratio mi/me . In contrast to the fully kinetic PIC simulation scheme, the fast electron cyclotron motion and plasma oscillations are systematically removed in the GeFi model, and hence one can employ the realistic mi/me . The GeFi simulations are benchmarked against and show excellent agreement with both the fully kinetic PIC simulation and the analytical eigenmode theory. Our studies indicate that, for small wavenumbers, ky, along the current direction, the most unstable eigenmodes are peaked at the location where k →.B → =0 , consistent with previous analytical and simulation studies. Here, B → is the equilibrium magnetic field and k → is the wavevector perpendicular to the nonuniformity direction. As ky increases, however, the most unstable eigenmodes are found to be peaked at k →.B → ≠0 . In addition, the simulation results indicate that varying mi/me , the current sheet width, and the guide magnetic field can affect the stability of LHDI. Simulations with the varying mass ratio confirm the lower hybrid frequency and wave number scalings.

  1. Construction of a 3D rGO-collagen hybrid scaffold for enhancement of the neural differentiation of mesenchymal stem cells.

    PubMed

    Guo, Weibo; Wang, Shu; Yu, Xin; Qiu, Jichuan; Li, Jianhua; Tang, Wei; Li, Zhou; Mou, Xiaoning; Liu, Hong; Wang, Zhonglin

    2016-01-28

    The cell-material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold because the surface of the scaffold can determine the fate of stem cells. A conductive surface is required for a scaffold to direct stem cells toward neural differentiation. However, most conductive polymers are toxic and not amenable to biological degradation, which restricts the design of neural tissue engineering scaffolds. In this study, we used a bioactive three-dimensional (3D) porcine acellular dermal matrix (PADM), which is mainly composed of type I collagen, as a basic material and successfully assembled a layer of reduced graphene oxide (rGO) nanosheets on the surface of the PADM channels to obtain a porous 3D, biodegradable, conductive and biocompatible PADM-rGO hybrid neural tissue engineering scaffold. Compared with the PADM scaffold, assembling the rGO into the scaffold did not induce a significant change in the microstructure but endowed the PADM-rGO hybrid scaffold with good conductivity. A comparison of the neural differentiation of rat bone-marrow-derived mesenchymal stem cells (MSCs) was performed by culturing the MSCs on PADM and PADM-rGO scaffolds in neuronal culture medium, followed by the determination of gene expression and immunofluorescence staining. The results of both the gene expression and protein level assessments suggest that the rGO-assembled PADM scaffold may promote the differentiation of MSCs into neuronal cells with higher protein and gene expression levels after 7 days under neural differentiation conditions. This study demonstrated that the PADM-rGO hybrid scaffold is a promising scaffold for neural tissue engineering; this scaffold can not only support the growth of MSCs at a high proliferation rate but also enhance the differentiation of MSCs into neural cells. PMID:26750302

  2. Construction of a 3D rGO-collagen hybrid scaffold for enhancement of the neural differentiation of mesenchymal stem cells.

    PubMed

    Guo, Weibo; Wang, Shu; Yu, Xin; Qiu, Jichuan; Li, Jianhua; Tang, Wei; Li, Zhou; Mou, Xiaoning; Liu, Hong; Wang, Zhonglin

    2016-01-28

    The cell-material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold because the surface of the scaffold can determine the fate of stem cells. A conductive surface is required for a scaffold to direct stem cells toward neural differentiation. However, most conductive polymers are toxic and not amenable to biological degradation, which restricts the design of neural tissue engineering scaffolds. In this study, we used a bioactive three-dimensional (3D) porcine acellular dermal matrix (PADM), which is mainly composed of type I collagen, as a basic material and successfully assembled a layer of reduced graphene oxide (rGO) nanosheets on the surface of the PADM channels to obtain a porous 3D, biodegradable, conductive and biocompatible PADM-rGO hybrid neural tissue engineering scaffold. Compared with the PADM scaffold, assembling the rGO into the scaffold did not induce a significant change in the microstructure but endowed the PADM-rGO hybrid scaffold with good conductivity. A comparison of the neural differentiation of rat bone-marrow-derived mesenchymal stem cells (MSCs) was performed by culturing the MSCs on PADM and PADM-rGO scaffolds in neuronal culture medium, followed by the determination of gene expression and immunofluorescence staining. The results of both the gene expression and protein level assessments suggest that the rGO-assembled PADM scaffold may promote the differentiation of MSCs into neuronal cells with higher protein and gene expression levels after 7 days under neural differentiation conditions. This study demonstrated that the PADM-rGO hybrid scaffold is a promising scaffold for neural tissue engineering; this scaffold can not only support the growth of MSCs at a high proliferation rate but also enhance the differentiation of MSCs into neural cells.

  3. Global Calibration Method of a Camera Using the Constraint of Line Features and 3D World Points

    NASA Astrophysics Data System (ADS)

    Xu, Guan; Zhang, Xinyuan; Li, Xiaotao; Su, Jian; Hao, Zhaobing

    2016-08-01

    We present a reliable calibration method using the constraint of 2D projective lines and 3D world points to elaborate the accuracy of the camera calibration. Based on the relationship between the 3D points and the projective plane, the constraint equations of the transformation matrix are generated from the 3D points and 2D projective lines. The transformation matrix is solved by the singular value decomposition. The proposed method is compared with the point-based calibration to verify the measurement validity. The mean values of the root-mean-square errors using the proposed method are 7.69×10-4, 6.98×10-4, 2.29×10-4, and 1.09×10-3 while the ones of the original method are 8.10×10-4, 1.29×10-2, 2.58×10-2, and 8.12×10-3. Moreover, the average logarithmic errors of the calibration method are evaluated and compared with the former method in different Gaussian noises and projective lines. The variances of the average errors using the proposed method are 1.70×10-5, 1.39×10-4, 1.13×10-4, and 4.06×10-4, which indicates the stability and accuracy of the method.

  4. Jovian Plasmas Torus Interaction with Europa. Plasma Wake Structure and Effect of Inductive Magnetic Field: 3D Hybrid Kinetic Simulation

    NASA Technical Reports Server (NTRS)

    Lipatov, A. S.; Cooper, J F.; Paterson, W. R.; Sittler, E. C., Jr.; Hartle, R. E.; Simpson, David G.

    2013-01-01

    The hybrid kinetic model supports comprehensive simulation of the interaction between different spatial and energetic elements of the Europa moon-magnetosphere system with respect to a variable upstream magnetic field and flux or density distributions of plasma and energetic ions, electrons, and neutral atoms. This capability is critical for improving the interpretation of the existing Europa flyby measurements from the Galileo Orbiter mission, and for planning flyby and orbital measurements (including the surface and atmospheric compositions) for future missions. The simulations are based on recent models of the atmosphere of Europa (Cassidy et al., 2007; Shematovich et al., 2005). In contrast to previous approaches with MHD simulations, the hybrid model allows us to fully take into account the finite gyroradius effect and electron pressure, and to correctly estimate the ion velocity distribution and the fluxes along the magnetic field (assuming an initial Maxwellian velocity distribution for upstream background ions). Photoionization, electron-impact ionization, charge exchange and collisions between the ions and neutrals are also included in our model. We consider the models with Oþ þ and Sþ þ background plasma, and various betas for background ions and electrons, and pickup electrons. The majority of O2 atmosphere is thermal with an extended non-thermal population (Cassidy et al., 2007). In this paper, we discuss two tasks: (1) the plasma wake structure dependence on the parameters of the upstream plasma and Europa's atmosphere (model I, cases (a) and (b) with a homogeneous Jovian magnetosphere field, an inductive magnetic dipole and high oceanic shell conductivity); and (2) estimation of the possible effect of an induced magnetic field arising from oceanic shell conductivity. This effect was estimated based on the difference between the observed and modeled magnetic fields (model II, case (c) with an inhomogeneous Jovian magnetosphere field, an inductive

  5. Critical factors affecting the 3D microstructural formation in hybrid conductive adhesive materials studied by X-ray nano-tomography

    NASA Astrophysics Data System (ADS)

    Chen-Wiegart, Yu-Chen Karen; Figueroa-Santos, Miriam Aileen; Petrash, Stanislas; Garcia-Miralles, Jose; Wang, Jun

    2014-12-01

    Conductive adhesives are found favorable in a wide range of applications including a lead-free solder in micro-chips, flexible and printable electronics and enhancing the performance of energy storage devices. Composite materials comprised of metallic fillers and a polymer matrix are of great interest to be implemented as hybrid conductive adhesives. Here we investigated a cost-effective conductive adhesive material consisting of silver-coated copper as micro-fillers using synchrotron-based three-dimensional (3D) X-ray nano-tomography. The key factors affecting the quality and performance of the material were quantitatively studied in 3D on the nanometer scale for the first time. A critical characteristic parameter, defined as a shape-factor, was determined to yield a high-quality silver coating, leading to satisfactory performance. A `stack-and-screen' mechanism was proposed to elaborate such a phenomenon. The findings and the technique developed in this work will facilitate the future advancement of conductive adhesives to have a great impact in micro-electronics and other applications.Conductive adhesives are found favorable in a wide range of applications including a lead-free solder in micro-chips, flexible and printable electronics and enhancing the performance of energy storage devices. Composite materials comprised of metallic fillers and a polymer matrix are of great interest to be implemented as hybrid conductive adhesives. Here we investigated a cost-effective conductive adhesive material consisting of silver-coated copper as micro-fillers using synchrotron-based three-dimensional (3D) X-ray nano-tomography. The key factors affecting the quality and performance of the material were quantitatively studied in 3D on the nanometer scale for the first time. A critical characteristic parameter, defined as a shape-factor, was determined to yield a high-quality silver coating, leading to satisfactory performance. A `stack-and-screen' mechanism was proposed to

  6. a Multiple Data Set Joint Inversion Global 3d P-Velocity Model of the Earth's Crust and Mantle for Improved Seismic Event Location

    NASA Astrophysics Data System (ADS)

    Ballard, S.; Begnaud, M. L.; Hipp, J. R.; Chael, E. P.; Encarnacao, A.; Maceira, M.; Yang, X.; Young, C. J.; Phillips, W.

    2013-12-01

    SALSA3D is a global 3D P wave velocity model of the Earth's crust and mantle developed specifically to provide seismic event locations that are more accurate and more precise than are locations from 1D and 2.5D models. In this paper, we present the most recent version of our model, for the first time jointly derived from multiple types of data: body wave travel times, surface wave group velocities, and gravity. The latter two are added to provide information in areas with poor body wave coverage, and are down-weighted in areas where body wave coverage is good. To constrain the inversions, we invoked empirical relations among the density, S velocity, and P velocity. We demonstrate the ability of the new SALSA3D model to reduce mislocations and generate statistically robust uncertainty estimates for a large set of realizations derived from a carefully chosen set of globally-distributed ground truth events. We obtain path-dependent travel time prediction uncertainties for our model by computing the full 3D model covariance matrix of our tomographic system and integrating the model slowness variance and covariance along paths of interest. This approach yields very low travel time prediction uncertainties for well-sampled paths through the Earth and higher uncertainties for paths that are poorly represented in the data set used to develop the model. While the calculation of path-dependent prediction uncertainties with this approach is computationally expensive, uncertainties can be pre-computed for a network of stations and stored in 3D lookup tables that can be quickly and efficiently interrogated using GeoTess software.

  7. A 3D Hybrid Model for Tissue Growth: The Interplay between Cell Population and Mass Transport Dynamics

    PubMed Central

    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

  8. 3D fiber-based hybrid nanogenerator for energy harvesting and as a self-powered pressure sensor.

    PubMed

    Li, Xiuhan; Lin, Zong-Hong; Cheng, Gang; Wen, Xiaonan; Liu, Ying; Niu, Simiao; Wang, Zhong Lin

    2014-10-28

    In the past years, scientists have shown that development of a power suit is no longer a dream by integrating the piezoelectric nanogenerator (PENG) or triboelectric nanogenerator (TENG) with commercial carbon fiber cloth. However, there is still no design applying those two kinds of NG together to collect the mechanical energy more efficiently. In this paper, we demonstrate a fiber-based hybrid nanogenerator (FBHNG) composed of TENG and PENG to collect the mechanical energy in the environment. The FBHNG is three-dimensional and can harvest the energy from all directions. The TENG is positioned in the core and covered with PENG as a coaxial core/shell structure. The PENG design here not only enhances the collection efficiency of mechanical energy by a single carbon fiber but also generates electric output when the TENG is not working. We also show the potential that the FBHNG can be weaved into a smart cloth to harvest the mechanical energy from human motions and act as a self-powered strain sensor. The instantaneous output power density of TENG and PENG can achieve 42.6 and 10.2 mW/m(2), respectively. And the rectified output of FBHNG has been applied to charge the commercial capacitor and drive light-emitting diodes, which are also designed as a self-powered alert system. PMID:25268317

  9. 3D fiber-based hybrid nanogenerator for energy harvesting and as a self-powered pressure sensor.

    PubMed

    Li, Xiuhan; Lin, Zong-Hong; Cheng, Gang; Wen, Xiaonan; Liu, Ying; Niu, Simiao; Wang, Zhong Lin

    2014-10-28

    In the past years, scientists have shown that development of a power suit is no longer a dream by integrating the piezoelectric nanogenerator (PENG) or triboelectric nanogenerator (TENG) with commercial carbon fiber cloth. However, there is still no design applying those two kinds of NG together to collect the mechanical energy more efficiently. In this paper, we demonstrate a fiber-based hybrid nanogenerator (FBHNG) composed of TENG and PENG to collect the mechanical energy in the environment. The FBHNG is three-dimensional and can harvest the energy from all directions. The TENG is positioned in the core and covered with PENG as a coaxial core/shell structure. The PENG design here not only enhances the collection efficiency of mechanical energy by a single carbon fiber but also generates electric output when the TENG is not working. We also show the potential that the FBHNG can be weaved into a smart cloth to harvest the mechanical energy from human motions and act as a self-powered strain sensor. The instantaneous output power density of TENG and PENG can achieve 42.6 and 10.2 mW/m(2), respectively. And the rectified output of FBHNG has been applied to charge the commercial capacitor and drive light-emitting diodes, which are also designed as a self-powered alert system.

  10. Extra high speed modified Lundell alternator parameters and open/short-circuit characteristics from global 3D-FE magnetic field solutions

    NASA Technical Reports Server (NTRS)

    Wang, R.; Demerdash, N. A.

    1992-01-01

    The combined magnetic vector potential - magnetic scalar potential method of computation of 3D magnetic fields by finite elements, introduced in a companion paper, is used for global 3D field analysis and machine performance computations under open-circuit and short-circuit conditions for an example 14.3 kVA modified Lundell alternator, whose magnetic field is of intrinsic 3D nature. The computed voltages and currents under these machine test conditions were verified and found to be in very good agreement with corresponding test data. Results of use of this modelling and computation method in the study of a design alteration example, in which the stator stack length of the example alternator is stretched in order to increase voltage and volt-ampere rating, are given here. These results demonstrate the inadequacy of conventional 2D-based design concepts and the imperative of use of this type of 3D magnetic field modelling in the design and investigation of such machines.

  11. Hybrid Macro-Porous Titanium Ornamented by Degradable 3D Gel/nHA Micro-Scaffolds for Bone Tissue Regeneration

    PubMed Central

    Yin, Bo; Ma, Pei; Chen, Jun; Wang, Hai; Wu, Gui; Li, Bo; Li, Qiang; Huang, Zhifeng; Qiu, Guixing; Wu, Zhihong

    2016-01-01

    Porous titanium is a kind of promising material for bone substitution, while its bio-inert property results in demand of modifications to improve the osteointegration capacity. In this study, gelatin (Gel) and nano-hydroxyapatite (nHA) were used to construct 3D micro-scaffolds in the pores of porous titanium in the ratios of Gel:nHA = 1:0, Gel:nHA = 1:1, and Gel:nHA = 1:3, respectively. Cell attachment and proliferation, and gene and protein expression levels of osteogenic markers were evaluated in MC3T3-E1 cells, followed by bone regeneration assessment in a rabbit radius defect model. All hybrid scaffolds with different composition ratio were found to have significant promotional effects in cell adhesion, proliferation and differentiation, in which the group with Gel:nHA = 1:1 showed the best performance in vitro, as well as the most bone regeneration volume in vivo. This 3D micro-scaffolds modification may be an innovative method for porous titanium ornamentation and shows potential application values in clinic. PMID:27092492

  12. Accurate and Fully Automatic Hippocampus Segmentation Using Subject-Specific 3D Optimal Local Maps Into a Hybrid Active Contour Model

    PubMed Central

    Gkontra, Polyxeni; Daras, Petros; Maglaveras, Nicos

    2014-01-01

    Assessing the structural integrity of the hippocampus (HC) is an essential step toward prevention, diagnosis, and follow-up of various brain disorders due to the implication of the structural changes of the HC in those disorders. In this respect, the development of automatic segmentation methods that can accurately, reliably, and reproducibly segment the HC has attracted considerable attention over the past decades. This paper presents an innovative 3-D fully automatic method to be used on top of the multiatlas concept for the HC segmentation. The method is based on a subject-specific set of 3-D optimal local maps (OLMs) that locally control the influence of each energy term of a hybrid active contour model (ACM). The complete set of the OLMs for a set of training images is defined simultaneously via an optimization scheme. At the same time, the optimal ACM parameters are also calculated. Therefore, heuristic parameter fine-tuning is not required. Training OLMs are subsequently combined, by applying an extended multiatlas concept, to produce the OLMs that are anatomically more suitable to the test image. The proposed algorithm was tested on three different and publicly available data sets. Its accuracy was compared with that of state-of-the-art methods demonstrating the efficacy and robustness of the proposed method. PMID:27170866

  13. Critical factors affecting the 3D microstructural formation in hybrid conductive adhesive materials studied by X-ray nano-tomography.

    PubMed

    Chen-Wiegart, Yu-chen Karen; Figueroa-Santos, Miriam Aileen; Petrash, Stanislas; Garcia-Miralles, Jose; Wang, Jun

    2015-01-21

    Conductive adhesives are found favorable in a wide range of applications including a lead-free solder in micro-chips, flexible and printable electronics and enhancing the performance of energy storage devices. Composite materials comprised of metallic fillers and a polymer matrix are of great interest to be implemented as hybrid conductive adhesives. Here we investigated a cost-effective conductive adhesive material consisting of silver-coated copper as micro-fillers using synchrotron-based three-dimensional (3D) X-ray nano-tomography. The key factors affecting the quality and performance of the material were quantitatively studied in 3D on the nanometer scale for the first time. A critical characteristic parameter, defined as a shape-factor, was determined to yield a high-quality silver coating, leading to satisfactory performance. A 'stack-and-screen' mechanism was proposed to elaborate such a phenomenon. The findings and the technique developed in this work will facilitate the future advancement of conductive adhesives to have a great impact in micro-electronics and other applications. PMID:25474162

  14. Time-Dependent Distribution Functions in C-Mod Calculated with the CQL3D-Hybrid-FOW, AORSA Full-Wave, and DC Lorentz Codes

    NASA Astrophysics Data System (ADS)

    Harvey, R. W. (Bob); Petrov, Yu. V.; Jaeger, E. F.; Berry, L. A.; Bonoli, P. T.; Bader, A.

    2015-11-01

    A time-dependent simulation of C-Mod pulsed ICRF power is made calculating minority hydrogen ion distribution functions with the CQL3D-Hybrid-FOW finite-orbit-width Fokker-Planck code. ICRF fields are calculated with the AORSA full wave code, and RF diffusion coefficients are obtained from these fields using the DC Lorentz gyro-orbit code. Prior results with a zero-banana-width simulation using the CQL3D/AORSA/DC time-cycles showed a pronounced enhancement of the H distribution in the perpendicular velocity direction compared to results obtained from Stix's quasilinear theory, in general agreement with experiment. The present study compares the new FOW results, including relevant gyro-radius effects, to determine the importance of these effects on the the NPA synthetic diagnostic time-dependence. The new NPA results give increased agreement with experiment, particularly in the ramp-down time after the ICRF pulse. Funded, through subcontract with Massachusetts Institute of Technology, by USDOE sponsored SciDAC Center for Simulation of Wave-Plasma Interactions.

  15. Hybrid Macro-Porous Titanium Ornamented by Degradable 3D Gel/nHA Micro-Scaffolds for Bone Tissue Regeneration.

    PubMed

    Yin, Bo; Ma, Pei; Chen, Jun; Wang, Hai; Wu, Gui; Li, Bo; Li, Qiang; Huang, Zhifeng; Qiu, Guixing; Wu, Zhihong

    2016-04-15

    Porous titanium is a kind of promising material for bone substitution, while its bio-inert property results in demand of modifications to improve the osteointegration capacity. In this study, gelatin (Gel) and nano-hydroxyapatite (nHA) were used to construct 3D micro-scaffolds in the pores of porous titanium in the ratios of Gel:nHA = 1:0, Gel:nHA = 1:1, and Gel:nHA = 1:3, respectively. Cell attachment and proliferation, and gene and protein expression levels of osteogenic markers were evaluated in MC3T3-E1 cells, followed by bone regeneration assessment in a rabbit radius defect model. All hybrid scaffolds with different composition ratio were found to have significant promotional effects in cell adhesion, proliferation and differentiation, in which the group with Gel:nHA = 1:1 showed the best performance in vitro, as well as the most bone regeneration volume in vivo. This 3D micro-scaffolds modification may be an innovative method for porous titanium ornamentation and shows potential application values in clinic.

  16. Hybrid local FEM/global LISA modeling of damped guided wave propagation in complex composite structures

    NASA Astrophysics Data System (ADS)

    Shen, Yanfeng; Cesnik, Carlos E. S.

    2016-09-01

    This paper presents a new hybrid modeling technique for the efficient simulation of guided wave generation, propagation, and interaction with damage in complex composite structures. A local finite element model is deployed to capture the piezoelectric effects and actuation dynamics of the transmitter, while the global domain wave propagation and interaction with structural complexity (structure features and damage) are solved utilizing a local interaction simulation approach (LISA). This hybrid approach allows the accurate modeling of the local dynamics of the transducers and keeping the LISA formulation in an explicit format, which facilitates its readiness for parallel computing. The global LISA framework was extended through the 3D Kelvin-Voigt viscoelasticity theory to include anisotropic damping effects for composite structures, as an improvement over the existing LISA formulation. The global LISA framework was implemented using the compute unified device architecture running on graphic processing units. A commercial preprocessor is integrated seamlessly with the computational framework for grid generation and material property allocation to handle complex structures. The excitability and damping effects are successfully captured by this hybrid model, with experimental validation using the scanning laser doppler vibrometry. To demonstrate the capability of our hybrid approach for complex structures, guided wave propagation and interaction with a delamination in a composite panel with stiffeners is presented.

  17. Hybrid local FEM/global LISA modeling of damped guided wave propagation in complex composite structures

    NASA Astrophysics Data System (ADS)

    Shen, Yanfeng; Cesnik, Carlos E. S.

    2016-09-01

    This paper presents a new hybrid modeling technique for the efficient simulation of guided wave generation, propagation, and interaction with damage in complex composite structures. A local finite element model is deployed to capture the piezoelectric effects and actuation dynamics of the transmitter, while the global domain wave propagation and interaction with structural complexity (structure features and damage) are solved utilizing a local interaction simulation approach (LISA). This hybrid approach allows the accurate modeling of the local dynamics of the transducers and keeping the LISA formulation in an explicit format, which facilitates its readiness for parallel computing. The global LISA framework was extended through the 3D Kelvin–Voigt viscoelasticity theory to include anisotropic damping effects for composite structures, as an improvement over the existing LISA formulation. The global LISA framework was implemented using the compute unified device architecture running on graphic processing units. A commercial preprocessor is integrated seamlessly with the computational framework for grid generation and material property allocation to handle complex structures. The excitability and damping effects are successfully captured by this hybrid model, with experimental validation using the scanning laser doppler vibrometry. To demonstrate the capability of our hybrid approach for complex structures, guided wave propagation and interaction with a delamination in a composite panel with stiffeners is presented.

  18. The LLNL-G3D global P-wave velocity model and the significance of the BayesLoc multiple-event location procedure

    NASA Astrophysics Data System (ADS)

    Simmons, N. A.; Myers, S. C.; Johannesson, G.; Matzel, E.

    2011-12-01

    LLNL-G3D is a global-scale model of P-wave velocity designed to accurately predict seismic travel times at regional and teleseismic distances simultaneously. The underlying goal of the model is to provide enhanced seismic event location capabilities. Previous versions of LLNL-G3D (versions 1 and 2) provide substantial improvements in event location accuracy via 3-D ray tracing. The latest models are based on ~2.7 million P and Pn arrivals that are re-processed using our global multi-event locator known as BayesLoc. Bayesloc is a formulation of the joint probability distribution across multiple-event location parameters, including hypocenters, travel time corrections, pick precision, and phase labels. Modeling the whole multiple-event system results in accurate locations and an internally consistent data set that is ideal for tomography. Our recently developed inversion approach (called Progressive Multi-level Tessellation Inversion or PMTI) captures regional trends and fine details where data warrant. Using PMTI, we model multiple heterogeneity scale lengths without defining parameter grids with variable densities based on some ad hoc criteria. LLNL-G3Dv3 (version 3) is produced with data generated with the BayesLoc procedure, recently modified to account for localized travel time trends via a multiple event clustering technique. We demonstrate the significance of BayesLoc processing, the impact on the resulting tomographic images, and the application of LLNL-G3D to seismic event location. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-491805.

  19. Indirect solid free form fabrication of local and global porous, biomimetic and composite 3D polymer-ceramic scaffolds.

    PubMed

    Taboas, J M; Maddox, R D; Krebsbach, P H; Hollister, S J

    2003-01-01

    Precise control over scaffold material, porosity, and internal pore architecture is essential for tissue engineering. By coupling solid free form (SFF) manufacturing with conventional sponge scaffold fabrication procedures, we have developed methods for casting scaffolds that contain designed and controlled locally porous and globally porous internal architectures. These methods are compatible with numerous bioresorbable and non-resorbable polymers, ceramics, and biologic materials. Phase separation, emulsion-solvent diffusion, and porogen leaching were used to create poly(L)lactide (PLA) scaffolds containing both computationally designed global pores (500, 600, or 800 microm wide channels) and solvent fashioned local pores (50-100 microm wide voids or 5-10 microm length plates). Globally porous PLA and polyglycolide/PLA discrete composites were made using melt processing. Biphasic scaffolds with mechanically interdigitated PLA and sintered hydroxyapatite regions were fabricated with 500 and 600 microm wide global pores. PLA scaffolds with complex internal architectures that mimicked human trabecular bone were produced. Our indirect fabrication using casting in SFF molds provided enhanced control over scaffold shape, material, porosity and pore architecture, including size, geometry, orientation, branching, and interconnectivity. These scaffolds that contain concurrent local and global pores, discrete material regions, and biomimetic internal architectures may prove valuable for multi-tissue and structural tissue interface engineering. PMID:12417192

  20. The Interaction of the Solar Wind with Solar Probe Plus - 3D Hybrid Simulation. Report 1; The Study for the Distance 4.5Rs

    NASA Technical Reports Server (NTRS)

    Lipatov, Alexander S.; Sittler, Edward C.; Hartle, Richard E.; Cooper, John F.

    2010-01-01

    Our report devotes a 3D numerical hybrid model of the interaction of the solar wind with the Solar Probe spacecraft. The SPP model includes 3 main parts, namely, a non-conducting heat shield, a support system, and cylindrical section or spacecraft bus that contains the particle analysis devices and antenna. One observes an excitation of the low frequency Alfven and whistler type wave directed by the magnetic field with an amplitude of about (0.06-0.6) V/m. The compression waves and the jumps in an electric field with an amplitude of about (0.15-0.7) V/m were also observed. The wave amplitudes are comparable to or greater than previously estimated max wave amplitudes that SPP is expected to measure. The results of our hybrid simulation will be useful for understanding the plasma environment near the SPP spacecraft at the distance 4.5 Rs. Future simulation will take into account the charging of the spacecraft, the charge separation effects, an outgassing from heat shield, a photoionization and an electron impact ionization effects near the spacecraft.

  1. The Interaction of the Solar Wind with Solar Probe Plus - 3D Hybrid Simulation. Report 1; The Study for the Distance 4.5Rs

    NASA Technical Reports Server (NTRS)

    Lipatov, Alexander S.; Sittler, Edward C.; Hartle, Richard E.; Cooper, John F.

    2010-01-01

    Our report devotes a 3D numerical hybrid model of the interaction of the solar wind with the Solar Probe spacecraft. The Solar Probe Plus (SPP) model includes 3 main parts, namely, a non-conducting heat shield, a support system, and cylindrical section or spacecraft bus that contains the particle analysis devices and antenna. One observes an excitation of the low frequency Alfven and whistler type wave directed by the magnetic field with an amplitude of about (0.06-0.6) V/m. The compression waves and the jumps in an electric field with an amplitude of about (0.15-0.7) V/m were also observed. The wave amplitudes are comparable to or greater than previously estimated max wave amplitudes that SPP is expected to measure. The results of our hybrid simulation will be useful for understanding the plasma environment near the SPP spacecraft at the distance 4.5 Rs. Future simulation will take into account the charging of the spacecraft, the charge separation effects, an outgassing from heat shield, a photoionization and an electron impact ionization effects near the spacecraft.

  2. Background and Pickup Ion Velocity Distribution Dynamics in Titan's Plasma Environment: 3D Hybrid Simulation and Comparison with CAPS T9 Observations

    NASA Technical Reports Server (NTRS)

    Lipatov, A. S.; Sittler, E. C., Jr.; Hartle, R. E.; Cooper, J. F.; Simpson, D. G.

    2011-01-01

    In this report we discuss the ion velocity distribution dynamics from the 3D hybrid simulation. In our model the background, pickup, and ionospheric ions are considered as a particles, whereas the electrons are described as a fluid. Inhomogeneous photoionization, electron-impact ionization and charge exchange are included in our model. We also take into account the collisions between the ions and neutrals. The current simulation shows that mass loading by pickup ions H(+); H2(+), CH4(+) and N2(+) is stronger than in the previous simulations when O+ ions are introduced into the background plasma. In our hybrid simulations we use Chamberlain profiles for the atmospheric components. We also include a simple ionosphere model with average mass M = 28 amu ions that were generated inside the ionosphere. The moon is considered as a weakly conducting body. Special attention will be paid to comparing the simulated pickup ion velocity distribution with CAPS T9 observations. Our simulation shows an asymmetry of the ion density distribution and the magnetic field, including the formation of the Alfve n wing-like structures. The simulation also shows that the ring-like velocity distribution for pickup ions relaxes to a Maxwellian core and a shell-like halo.

  3. Three-Dimensional (3-D) Printing: A Cost-Effective Solution for Improving Global Accessibility to Prostheses.

    PubMed

    Silva, Kyle; Rand, Stephanie; Cancel, David; Chen, Yuxi; Kathirithamby, Rani; Stern, Michelle

    2015-12-01

    The lack of access to prostheses is a global problem, partially caused by the high cost associated with the current manufacturing process. Three-dimensional printing is gaining use in the medical field, and one such area is prosthetics. In addition to using cost-effective materials, this technology allows for rapid prototyping, making it an efficient solution for the development of affordable prostheses. If the rehabilitation medicine community embraces this novel technology, we can help alleviate the global disparity of access to prostheses. PMID:26709247

  4. A Non-linear Conjugate Gradient Numerical Inverse Solution for the Problem of 3-D Global Electromagnetic Induction

    NASA Astrophysics Data System (ADS)

    Kelbert, A.; Schultz, A.; Egbert, G.

    2006-12-01

    We address the non-linear ill-posed inverse problem of reconstructing the global three-dimensional distribution of electrical conductivity in Earth's mantle. The authors have developed a numerical regularized least-squares inverse solution based on the non-linear conjugate gradients approach. We apply this methodology to the most current low-frequency global observatory data set by Fujii &Schultz (2002), that includes c- and d-responses. We obtain 4-8 layer models satisfying the data. We then describe the features common to all these models and discuss the resolution of our method.

  5. Dynamics of pickup ion velocity distribution function in Titan's plasma environment (TA encounter): 3D hybrid kinetic modeling and comparison with CAPS observations

    NASA Astrophysics Data System (ADS)

    Simpson, D. G.; Lipatov, A. S.; Sittler, E. C.; Hartle, R. E.; Cooper, J. F.

    2013-12-01

    Wave-particle interactions play a very important role in the plasma dynamics near Titan: mass loading, excitation of the low-frequency waves and the formation of the particle velocity distribution function, e.g. ring/shell-like distributions, etc. The kinetic approach is important for estimation of the collision processes e.g. a charge exchange. The particle velocity distribution function also plays a key role for understanding the observed particle fluxes. In this report we discuss the ion velocity distribution function dynamics from 3D hybrid modeling. The modeling is based on recent analysis of the Cassini Plasma Spectrometer (CAPS) ion measurements during the TA flyby. In our model the background ions, all pickup ions, and ionospheric ions are considered as particles, whereas the electrons are described as a fluid. Inhomogeneous photoionization, electron-impact ionization and charge exchange are included in our model. The temperatures of the background electrons and pickup electrons were also included into the generalized Ohm's law. We also take into account the collisions between the ions and neutrals. We use Chamberlain profiles for the exosphere's components and include a simple ionosphere model with M=28 ions that were generated inside the ionosphere. The moon is considered as a weakly conducting body. Our modeling shows that interaction between background plasma and pickup ions H+, H2+, CH4+ and N2+ has a more complicated structure than was observed in the T9 flyby and modeling due to the large gyroradius of the background O+ ions [1,2,3,4]. Special attention will be paid to comparing the simulated pickup ion velocity distribution with CAPS TA observations. We also compare our kinetic modeling with other hybrid and MHD modeling of Titan's environment. References [1] Sittler, E.C., et al., Energy Deposition Processes in Titan's Upper Atmosphere and Its Induced Magnetosphere. In: Titan from Cassini-Huygens, Brown, R.H., Lebreton J.P., Waite, J.H., Eds

  6. Towards global scale coastal flood hazard in Delta Cities with 30-meter SRTM and 3D_i

    NASA Astrophysics Data System (ADS)

    Winsemius, Hessel; Verhoeven, Govert; Van Leeuwen, Elgard; Van der Klis, Hanneke; Van Wesenbeeck, Bregje; Cumiskey, Lydia; Verlaan, Martin; Muis, Sanne; Ward, Philip; Kwadijk, Jaap

    2015-04-01

    Most attempts to globally simulate inundation at the land-coast interface rely on maximum flood level GIS-based flood spreading models. These are generally not mass conservative, do not account for the genesis of tidal and surges in time, and do not include channel geometry and surface roughness. Furthermore, these methods cannot be used to study the impact of hazard reducing intervention measures that increase roughness at the land-coast interface. These measures include breakwaters and coastal ecosystems, such as mangrove forests and shell fish and coral reefs. Recently, new datasets and models are becoming available that allow us to greatly improve simulation of inundation in global deltas in a rapid and computationally feasible way. In this poster we demonstrate the feasibility of modelling all global deltas with strongly urbanised areas explicitly using these datasets and models. This will allow initiatives such as the 100 resilient cities (Rockefeller foundation) and the 'making cities resilient' campaign (UNISDR) to tackle the issue of coastal flood risk efficiently. We propose to use the following materials: A subgrid enabling 1D-2D model code Outputs from a global tidal and storm surge model Open topographical data We demonstrate the feasibility of this approach by modelling the Mississippi delta with: a) a lidar derived topography dataset (www.gis.ms.gov/); and b) the recently released 30 meter elevation dataset from the Shuttle Radar Topography Mission. We use the new 3Di subgrid code to rapidly schematise the vast delta area with a quadtree mesh. We force the model at the boundaries with water level estimates during the Katrina cyclone. We invite scientists working on global scale inundation modelling to visit our poster in order to discuss possibilities and limitations of the proposed methods related to model codes, data quality and calibration.

  7. The GPlates Portal: Cloud-Based Interactive 3D Visualization of Global Geophysical and Geological Data in a Web Browser.

    PubMed

    Müller, R Dietmar; Qin, Xiaodong; Sandwell, David T; Dutkiewicz, Adriana; Williams, Simon E; Flament, Nicolas; Maus, Stefan; Seton, Maria

    2016-01-01

    The pace of scientific discovery is being transformed by the availability of 'big data' and open access, open source software tools. These innovations open up new avenues for how scientists communicate and share data and ideas with each other and with the general public. Here, we describe our efforts to bring to life our studies of the Earth system, both at present day and through deep geological time. The GPlates Portal (portal.gplates.org) is a gateway to a series of virtual globes based on the Cesium Javascript library. The portal allows fast interactive visualization of global geophysical and geological data sets, draped over digital terrain models. The globes use WebGL for hardware-accelerated graphics and are cross-platform and cross-browser compatible with complete camera control. The globes include a visualization of a high-resolution global digital elevation model and the vertical gradient of the global gravity field, highlighting small-scale seafloor fabric such as abyssal hills, fracture zones and seamounts in unprecedented detail. The portal also features globes portraying seafloor geology and a global data set of marine magnetic anomaly identifications. The portal is specifically designed to visualize models of the Earth through geological time. These space-time globes include tectonic reconstructions of the Earth's gravity and magnetic fields, and several models of long-wavelength surface dynamic topography through time, including the interactive plotting of vertical motion histories at selected locations. The globes put the on-the-fly visualization of massive data sets at the fingertips of end-users to stimulate teaching and learning and novel avenues of inquiry.

  8. The GPlates Portal: Cloud-Based Interactive 3D Visualization of Global Geophysical and Geological Data in a Web Browser.

    PubMed

    Müller, R Dietmar; Qin, Xiaodong; Sandwell, David T; Dutkiewicz, Adriana; Williams, Simon E; Flament, Nicolas; Maus, Stefan; Seton, Maria

    2016-01-01

    The pace of scientific discovery is being transformed by the availability of 'big data' and open access, open source software tools. These innovations open up new avenues for how scientists communicate and share data and ideas with each other and with the general public. Here, we describe our efforts to bring to life our studies of the Earth system, both at present day and through deep geological time. The GPlates Portal (portal.gplates.org) is a gateway to a series of virtual globes based on the Cesium Javascript library. The portal allows fast interactive visualization of global geophysical and geological data sets, draped over digital terrain models. The globes use WebGL for hardware-accelerated graphics and are cross-platform and cross-browser compatible with complete camera control. The globes include a visualization of a high-resolution global digital elevation model and the vertical gradient of the global gravity field, highlighting small-scale seafloor fabric such as abyssal hills, fracture zones and seamounts in unprecedented detail. The portal also features globes portraying seafloor geology and a global data set of marine magnetic anomaly identifications. The portal is specifically designed to visualize models of the Earth through geological time. These space-time globes include tectonic reconstructions of the Earth's gravity and magnetic fields, and several models of long-wavelength surface dynamic topography through time, including the interactive plotting of vertical motion histories at selected locations. The globes put the on-the-fly visualization of massive data sets at the fingertips of end-users to stimulate teaching and learning and novel avenues of inquiry. PMID:26960151

  9. The GPlates Portal: Cloud-Based Interactive 3D Visualization of Global Geophysical and Geological Data in a Web Browser

    PubMed Central

    Müller, R. Dietmar; Qin, Xiaodong; Sandwell, David T.; Dutkiewicz, Adriana; Williams, Simon E.; Flament, Nicolas; Maus, Stefan; Seton, Maria

    2016-01-01

    The pace of scientific discovery is being transformed by the availability of ‘big data’ and open access, open source software tools. These innovations open up new avenues for how scientists communicate and share data and ideas with each other and with the general public. Here, we describe our efforts to bring to life our studies of the Earth system, both at present day and through deep geological time. The GPlates Portal (portal.gplates.org) is a gateway to a series of virtual globes based on the Cesium Javascript library. The portal allows fast interactive visualization of global geophysical and geological data sets, draped over digital terrain models. The globes use WebGL for hardware-accelerated graphics and are cross-platform and cross-browser compatible with complete camera control. The globes include a visualization of a high-resolution global digital elevation model and the vertical gradient of the global gravity field, highlighting small-scale seafloor fabric such as abyssal hills, fracture zones and seamounts in unprecedented detail. The portal also features globes portraying seafloor geology and a global data set of marine magnetic anomaly identifications. The portal is specifically designed to visualize models of the Earth through geological time. These space-time globes include tectonic reconstructions of the Earth’s gravity and magnetic fields, and several models of long-wavelength surface dynamic topography through time, including the interactive plotting of vertical motion histories at selected locations. The globes put the on-the-fly visualization of massive data sets at the fingertips of end-users to stimulate teaching and learning and novel avenues of inquiry. PMID:26960151

  10. LLNL-Earth3D

    SciTech Connect

    2013-10-01

    Earth3D is a computer code designed to allow fast calculation of seismic rays and travel times through a 3D model of the Earth. LLNL is using this for earthquake location and global tomography efforts and such codes are of great interest to the Earth Science community.

  11. The role of the hybridization between Mn 3d and O 2p orbitals in the existence of the Griffiths phase in La0.85Ca0.15MnO3.

    PubMed

    Zhang, Hong-guang; Shi, Jiang-jian; Li, Yong-tao; Dong, Xue-guang; Ge, Xiao-peng; Liu, Hao; Hou, Qing-teng; Li, Qi; Tang, Yan-kun

    2014-04-01

    Favourable conditions for the existence of the Griffiths phase in the La0.85Ca0.15MnO3 compound are experimentally investigated in terms of electronic and lattice structure by temperature-dependent x-ray absorption spectroscopy, valence band photoemission spectroscopy, and x-ray diffraction experiments. The chemical shifts of Mn L-edge and O K-edge x-ray absorption lines in the Griffiths phase are understood to be related to the hybridization between Mn 3d and O 2p states instead of the variation of Mn valence states. Valence band spectra also indicate that the hybridization of O 2p with Mn 3d is enhanced in the Griffiths phase. From a 2D diluted Ising ferromagnet model, this hybridization between Mn 3d and O 2p orbitals surely enhances the Griffiths phase feature. PMID:24637382

  12. A Satellite-Based Method for Estimating Global Oceanic DMS and Its Application in a 3-D Atmospheric GCM

    SciTech Connect

    Belviso, S.; Moulin, C.; Bopp, L.; Cosme, E.; Chapman, Elaine G.; Aranami, K.

    2003-01-01

    The flux of dimethylsulfide (DMS) from the world's oceans is the largest known source of biogenically-derived reduced sulfur compounds to the atmosphere. Its impact on atmospheric chemistry and radiative transfer is an active area of scientific research, and DMS is routinely included in three-dimensional global climate change and chemical transport models. In such models, DMS fluxes typically are based on global sea surface DMS concentrations and wind-speed-dependent parameterizations of the mass transfer coefficient. We show here how sea surface DMS concentrations can be estimated from satellite-based Sea-viewing Wide Field-of-View Sensor (SeaWiFS) observations of sea surface chlorophyll a. We compare SeaWiFS-derived DMS concentrations for the twelve month period November 1997 through October 1998 with shipboard measurements made in the Pacific and Indian Oceans. The SeaWiFS-derived DMS distributions demonstrate improved capture of DMS spatial variability in Southern Ocean surface waters relative to previous works, but underestimate the amplitude of seasonal DMS variations in this region. Using the three-dimensional Atmospheric General Circulation Model of the Laboratoire de M?orologie Dynamique, model-time-step wind speeds, an atmospheric-stability-dependent parameterization of the mass transfer coefficient, and our SeaWiFS-derived oceanic DMS distributions, we estimate an annual Southern Ocean DMS emission of 6.8 Tg S yr-1. This value represents approximately one-third of the annual global DMS marine emission, and underscores the importance of this region as a source of natural sulfur emissions.

  13. Dopant-induced 2D-3D transition in small Au-containing clusters: DFT-global optimisation of 8-atom Au-Ag nanoalloys.

    PubMed

    Heiles, Sven; Logsdail, Andrew J; Schäfer, Rolf; Johnston, Roy L

    2012-02-21

    A genetic algorithm (GA) coupled with density functional theory (DFT) calculations is used to perform global optimisations for all compositions of 8-atom Au-Ag bimetallic clusters. The performance of this novel GA-DFT approach for bimetallic nanoparticles is tested for structures reported in the literature. New global minimum structures for various compositions are predicted and the 2D-3D transition is located. Results are explained with the aid of an analysis of the electronic density of states. The chemical ordering of the predicted lowest energy isomers are explained via a detailed analysis of the charge separation and mixing energies of the bimetallic clusters. Finally, dielectric properties are computed and the composition and dimensionality dependence of the electronic polarizability and dipole moment is discussed, enabling predictions to be made for future electric beam deflection experiments.

  14. Study of morphology effects on magnetic interactions and band gap variations for 3d late transition metal bi-doped ZnO nanostructures by hybrid DFT calculations

    NASA Astrophysics Data System (ADS)

    Datta, Soumendu; Kaphle, Gopi Chandra; Baral, Sayan; Mookerjee, Abhijit

    2015-08-01

    Using density functional theory (DFT) based electronic structure calculations, the effects of morphology of semiconducting nanostructures on the magnetic interaction between two magnetic dopant atoms as well as a possibility of tuning band gaps have been studied in the case of the bi-doped (ZnO)24 nanostructures with the impurity dopant atoms of the 3d late transition metals—Mn, Fe, Co, Ni, and Cu. To explore the morphology effect, three different structures of the host (ZnO)24 nano-system, having different degrees of spatial confinement, have been considered: a two dimensional nanosheet, a one dimensional nanotube, and a finite cage-shaped nanocluster. The present study employs hybrid density functional theory to accurately describe the electronic structure of all the systems. It is shown here that the magnetic coupling between the two dopant atoms remains mostly anti-ferromagnetic in the course of changing the morphology from the sheet geometry to the cage-shaped geometry of the host systems, except for the case of energetically most stable bi-Mn doping, which shows a transition from ferromagnetic to anti-ferromagnetic coupling with decreasing aspect ratio of the host system. The effect of the shape change, however, has a significant effect on the overall band gap variations of both the pristine as well as all the bi-doped systems, irrespective of the nature of the dopant atoms and provides a means for easy tunability of their optoelectronic properties.

  15. Study of morphology effects on magnetic interactions and band gap variations for 3d late transition metal bi-doped ZnO nanostructures by hybrid DFT calculations.

    PubMed

    Datta, Soumendu; Kaphle, Gopi Chandra; Baral, Sayan; Mookerjee, Abhijit

    2015-08-28

    Using density functional theory (DFT) based electronic structure calculations, the effects of morphology of semiconducting nanostructures on the magnetic interaction between two magnetic dopant atoms as well as a possibility of tuning band gaps have been studied in the case of the bi-doped (ZnO)24 nanostructures with the impurity dopant atoms of the 3d late transition metals-Mn, Fe, Co, Ni, and Cu. To explore the morphology effect, three different structures of the host (ZnO)24 nano-system, having different degrees of spatial confinement, have been considered: a two dimensional nanosheet, a one dimensional nanotube, and a finite cage-shaped nanocluster. The present study employs hybrid density functional theory to accurately describe the electronic structure of all the systems. It is shown here that the magnetic coupling between the two dopant atoms remains mostly anti-ferromagnetic in the course of changing the morphology from the sheet geometry to the cage-shaped geometry of the host systems, except for the case of energetically most stable bi-Mn doping, which shows a transition from ferromagnetic to anti-ferromagnetic coupling with decreasing aspect ratio of the host system. The effect of the shape change, however, has a significant effect on the overall band gap variations of both the pristine as well as all the bi-doped systems, irrespective of the nature of the dopant atoms and provides a means for easy tunability of their optoelectronic properties.

  16. High-performance hybrid supercapacitor with 3D hierarchical porous flower-like layered double hydroxide grown on nickel foam as binder-free electrode

    NASA Astrophysics Data System (ADS)

    Zhang, Luojiang; Hui, Kwun Nam; San Hui, Kwan; Lee, Haiwon

    2016-06-01

    The synthesis of layered double hydroxide (LDH) as electroactive material has been well reported; however, fabricating an LDH electrode with excellent electrochemical performance at high current density remains a challenge. In this paper, we report a 3D hierarchical porous flower-like NiAl-LDH grown on nickel foam (NF) through a liquid-phase deposition method as a high-performance binder-free electrode for energy storage. With large ion-accessible surface area as well as efficient electron and ion transport pathways, the prepared LDH-NF electrode achieves high specific capacity (1250 C g-1 at 2 A g-1 and 401 C g-1 at 50 A g-1) after 5000 cycles of activation at 20 A g-1 and high cycling stability (76.7% retention after another 5000 cycles at 50 A g-1), which is higher than those of most previously reported NiAl-LDH-based materials. Moreover, a hybrid supercapacitor with LDH-NF as the positive electrode and porous graphene nanosheet coated on NF (GNS-NF) as the negative electrode, delivers high energy density (30.2 Wh kg-1 at a power density of 800 W kg-1) and long cycle life, which outperforms the other devices reported in the literature. This study shows that the prepared LDH-NF electrode offers great potential in energy storage device applications.

  17. Study of morphology effects on magnetic interactions and band gap variations for 3d late transition metal bi-doped ZnO nanostructures by hybrid DFT calculations

    SciTech Connect

    Datta, Soumendu Baral, Sayan; Mookerjee, Abhijit; Kaphle, Gopi Chandra

    2015-08-28

    Using density functional theory (DFT) based electronic structure calculations, the effects of morphology of semiconducting nanostructures on the magnetic interaction between two magnetic dopant atoms as well as a possibility of tuning band gaps have been studied in the case of the bi-doped (ZnO){sub 24} nanostructures with the impurity dopant atoms of the 3d late transition metals—Mn, Fe, Co, Ni, and Cu. To explore the morphology effect, three different structures of the host (ZnO){sub 24} nano-system, having different degrees of spatial confinement, have been considered: a two dimensional nanosheet, a one dimensional nanotube, and a finite cage-shaped nanocluster. The present study employs hybrid density functional theory to accurately describe the electronic structure of all the systems. It is shown here that the magnetic coupling between the two dopant atoms remains mostly anti-ferromagnetic in the course of changing the morphology from the sheet geometry to the cage-shaped geometry of the host systems, except for the case of energetically most stable bi-Mn doping, which shows a transition from ferromagnetic to anti-ferromagnetic coupling with decreasing aspect ratio of the host system. The effect of the shape change, however, has a significant effect on the overall band gap variations of both the pristine as well as all the bi-doped systems, irrespective of the nature of the dopant atoms and provides a means for easy tunability of their optoelectronic properties.

  18. Study of morphology effects on magnetic interactions and band gap variations for 3d late transition metal bi-doped ZnO nanostructures by hybrid DFT calculations.

    PubMed

    Datta, Soumendu; Kaphle, Gopi Chandra; Baral, Sayan; Mookerjee, Abhijit

    2015-08-28

    Using density functional theory (DFT) based electronic structure calculations, the effects of morphology of semiconducting nanostructures on the magnetic interaction between two magnetic dopant atoms as well as a possibility of tuning band gaps have been studied in the case of the bi-doped (ZnO)24 nanostructures with the impurity dopant atoms of the 3d late transition metals-Mn, Fe, Co, Ni, and Cu. To explore the morphology effect, three different structures of the host (ZnO)24 nano-system, having different degrees of spatial confinement, have been considered: a two dimensional nanosheet, a one dimensional nanotube, and a finite cage-shaped nanocluster. The present study employs hybrid density functional theory to accurately describe the electronic structure of all the systems. It is shown here that the magnetic coupling between the two dopant atoms remains mostly anti-ferromagnetic in the course of changing the morphology from the sheet geometry to the cage-shaped geometry of the host systems, except for the case of energetically most stable bi-Mn doping, which shows a transition from ferromagnetic to anti-ferromagnetic coupling with decreasing aspect ratio of the host system. The effect of the shape change, however, has a significant effect on the overall band gap variations of both the pristine as well as all the bi-doped systems, irrespective of the nature of the dopant atoms and provides a means for easy tunability of their optoelectronic properties. PMID:26328845

  19. Impact of the IMF rotation on the cusp dynamics on the dayside: Global 3D PIC simulations

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Cai, D.; Lembege, B.; Nishikawa, K.-I.

    The dynamics of the cusp region is analyzed with a new version of a global three-dimensional full particle simulation with changing the interplanetary magnetic field IMF direction progressively from northward to duskward then duskward to southward With the initial northward IMF bands of weak magnetic field sash form poleward of the cusp at high latitudes in each hemisphere and at high altitudes these sashes are located approximately around the pole axis As the IMF rotates duskward these sashes move toward the equator within opposite quadrants Then as the duskward-oriented IMF continue to rotate toward southward these sashes move further and reach the dayside magnetopause at the equator During the progressive rotation of the IMF from northward to duskward i the sash region widens towards lower latitudes banana-shape and with the duskward IMF ii the size of the banana-shape region becomes minimum and its location stops around a maximum deviation of 45degree from the polar axis It should be noted that the sashes are extended from the dayside to the nightside tailward The motion of the sashes is also analyzed during the IMF rotation form duskward to southward

  20. Impact of the IMF rotation on the cusp dynamics on the dayside: Global 3D PIC simulations

    NASA Astrophysics Data System (ADS)

    Tao, W.; Cai, D.; Lembege, B.; Nishikawa, K.

    2005-12-01

    The dynamics of the cusp region as the interplanetary magnetic field (IMF) progressively changes its direction from northward to duskward is analysed with a new version of a global three-dimensional full particle simulation. For northward IMF, bands of weak magnetic field (sash) form poleward of the cusp at high latitudes in each hemisphere (and at high altitudes); these sashs are centered approximately around the pole axis. However, as the newly duskward-oriented IMF approaches and interacts with the magnetosphere, these sashs move to the equator (within opposite quadrants). During the progressive rotation of the IMF, this motion is decomposed in the plane perpendicular to the solar wind as follows: (i) the "sash" region widens towards lower latitudes ("banana-shape"), and (ii) the size of the "banana-shape" region strongly shrinks and its location stabilizes around a maximum deviation of 45?. In addition, this motion is observed both on the day and the night sides where sashs are simultaneously observed. Characteristic time and space scales of the cusp motion are indicated, in order to be compare with results deduced from previous MHD simulations. Changes of local reconnection in the cusp region are analysed.

  1. Evaluating the Credibility of Transport Processes in the Global Modeling Initiative 3D Model Simulations of Ozone Recovery

    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).

  2. A global 3D P-Velocity model of the Earth%3CU%2B2019%3Es crust and mantle for improved event location.

    SciTech Connect

    Ballard, Sanford; Encarnacao, Andre Villanova; Begnaud, Michael A.; Rowe, Charlotte A.; Lewis, Jennifer E.; Young, Christopher John; Chang, Marcus C.; Hipp, James Richard

    2010-05-01

    To test the hypothesis that high quality 3D Earth models will produce seismic event locations which are more accurate and more precise, we are developing a global 3D P wave velocity model of the Earth's crust and mantle using seismic tomography. In this paper, we present the most recent version of our model, SALSA3D (SAndia LoS Alamos) version 1.4, and demonstrate its ability to reduce mislocations for a large set of realizations derived from a carefully chosen set of globally-distributed ground truth events. Our model is derived from the latest version of the Ground Truth (GT) catalog of P and Pn travel time picks assembled by Los Alamos National Laboratory. To prevent over-weighting due to ray path redundancy and to reduce the computational burden, we cluster rays to produce representative rays. Reduction in the total number of ray paths is > 55%. The model is represented using the triangular tessellation system described by Ballard et al. (2009), which incorporates variable resolution in both the geographic and radial dimensions. For our starting model, we use a simplified two layer crustal model derived from the Crust 2.0 model over a uniform AK135 mantle. Sufficient damping is used to reduce velocity adjustments so that ray path changes between iterations are small. We obtain proper model smoothness by using progressive grid refinement, refining the grid only around areas with significant velocity changes from the starting model. At each grid refinement level except the last one we limit the number of iterations to prevent convergence thereby preserving aspects of broad features resolved at coarser resolutions. Our approach produces a smooth, multi-resolution model with node density appropriate to both ray coverage and the velocity gradients required by the data. This scheme is computationally expensive, so we use a distributed computing framework based on the Java Parallel Processing Framework, providing us with {approx}400 processors. Resolution of our model

  3. Spontaneous development of arcuate single-sided subduction in global 3-D mantle convection models with a free surface

    NASA Astrophysics Data System (ADS)

    Crameri, Fabio; Tackley, Paul

    2014-05-01

    The work presented aims at a better understanding of plate tectonics, a crucial dynamical feature within the global framework of mantle convection. Special focus is given to the interaction of subduction-related mantle flow and surface topography. Thereby, the application of a numerical model with two key functional requirements is essential: an evolution over a long time period to naturally model mantle flow and a physically correct topography calculation. The global mantle convection model presented in Crameri et al. (2012a) satisfies both of these requirements. First, it is efficiently calculated by the finite-volume code Stag-YY (e.g., Tackley 2008) using a multi-grid method on a fully staggered grid. Second, it applies the sticky-air method (Matsumoto and Tomoda 1983; Schmeling et al, 2008) and thus approximates a free surface when the sticky-air parameters are chosen carefully (Crameri et al., 2012b). This leads to dynamically self-consistent mantle convection with realistic, single-sided subduction. New insights are thus gained into the interplay of obliquely sinking plates, toroidal mantle flow and the arcuate shape of slabs and trenches. Numerous two-dimensional experiments provide optimal parameter setups that are applied to three-dimensional models in Cartesian and fully spherical geometries. Features observed and characterised in the latter experiments give important insight into the strongly variable behaviour of subduction zones along their strike. This includes (i) the spontaneous development of arcuate trench geometry, (ii) regional subduction polarity reversals and slab tearing, and the newly discovered features (iii) 'slab tunnelling' and (iv) 'back-slab spiral flow'. Overall, this study demonstrates the strong interaction between surface topography and mantle currents and highlights the variability of subduction zones and their individual segments. REFERENCES Crameri, F., P. J. Tackley, I. Meilick, T. V. Gerya, and B. J. P. Kaus (2012a), A free

  4. 23rd Solar Cycle in global response in composition of the atmosphere between the ground and 90 km : 3D simulations with CHARM model

    NASA Astrophysics Data System (ADS)

    Krivolutsky, Alexei A.

    The response in ozone and other chemical species of the Earth’s atmosphere have been simulated with new version of three-dimentional photochemical global transport model CHARM (CHemical Atmospheric Research Model), developed at the Laboratory for Atmospheric Chemistry and Dynamics of Central Aerological Observatory. Model describes the interaction between 40 chemical species involved in 140 photochemical reactions. “Family” technique is used for solving kinetic part of the model equations and Prather’s scheme used to describe advection. 3D global wind components and temperature field (daily averaged) calculated by GCM ARM (Atmospheric Research Model) were used in simulations. Solar cycle signal in UV solar irradiance variations measured from space (SIM and other instruments) has been introduced in the model. External forcing used in numerical scenario described unusual features of 23rd solar cycle: long and deep its minima. So that, the amplitude of external signal (max-min) was really more than in previous cycles. The results of simulations showed global structure of ozone response, which is mostly positive. At the same time the regions of negative ozone changes at high latitudes exist. The response of tropospheric ozone was also found around the equator. NOy global changes responsible for negative ozone response is also presented. This work was supported by Russian Science Foundation for Basic Research (grant N 13-05-0105213).

  5. A global 3-D model to simulate long-range transport of PAHs: Effect of climate on transport to the Arctic

    NASA Astrophysics Data System (ADS)

    Friedman, C. L.; Selin, N. E.

    2011-12-01

    We simulate the long-range transport of polycyclic aromatic hydrocarbons (PAHs) to the Arctic under present and future climate using a global 3-D chemical transport model (GEOS-Chem). PAHs, toxic byproducts of combustion, reach the Arctic by long-range atmospheric transport. PAHs are semivolatile compounds that partition between the gas and particle phases. We implement temperature-dependent PAH partitioning into hydrophobic organic carbon (OC) and black carbon (BC) aerosols in the model to simulate this behavior. First, we test the validity of the model by comparing results to global measurements of the PAHs phenanthrene (PHE), pyrene (PYR), and benzo[a]pyrene (BaP) and find that for mean global and mean Arctic concentrations, measurements and model results are not statistically different and that the model captures 64 - 74% (r2s) of the concentration variability in non-urban locations. We then simulate daily transport of PHE, PYR, and BaP to the Arctic for the years 2005-2009. Preliminary results suggest the model captures up to 50% (r2s) of the variability in Arctic concentrations, and is able to capture episodic events. Source-receptor analyses indicate European and Russian sources account for approximately 80% of PAHs in the Arctic. The sensitivity of PAH transport to simulated future climate meteorology (GCAP) and to variable OC and BC concentrations is investigated, particularly with respect to transport to the Arctic and remote exposures. The implications for regional and global PAH regulatory policies are discussed.

  6. New Models of Hybrid Leadership in Global Higher Education

    ERIC Educational Resources Information Center

    Tonini, Donna C.; Burbules, Nicholas C.; Gunsalus, C. K.

    2016-01-01

    This manuscript highlights the development of a leadership preparation program known as the Nanyang Technological University Leadership Academy (NTULA), exploring the leadership challenges unique to a university undergoing rapid growth in a highly multicultural context, and the hybrid model of leadership it developed in response to globalization.…

  7. Low-cost photodynamic therapy devices for global health settings: Characterization of battery-powered LED performance and smartphone imaging in 3D tumor models.

    PubMed

    Hempstead, Joshua; Jones, Dustin P; Ziouche, Abdelali; Cramer, Gwendolyn M; Rizvi, Imran; Arnason, Stephen; Hasan, Tayyaba; Celli, Jonathan P

    2015-01-01

    A lack of access to effective cancer therapeutics in resource-limited settings is implicated in global cancer health disparities between developed and developing countries. Photodynamic therapy (PDT) is a light-based treatment modality that has exhibited safety and efficacy in the clinic using wavelengths and irradiances achievable with light-emitting diodes (LEDs) operated on battery power. Here we assess low-cost enabling technology to extend the clinical benefit of PDT to regions with little or no access to electricity or medical infrastructure. We demonstrate the efficacy of a device based on a 635 nm high-output LED powered by three AA disposable alkaline batteries, to achieve strong cytotoxic response in monolayer and 3D cultures of A431 squamous carcinoma cells following photosensitization by administering aminolevulinic acid (ALA) to induce the accumulation of protoporphyrin IX (PpIX). Here we characterize challenges of battery-operated device performance, including battery drain and voltage stability specifically over relevant PDT dose parameters. Further motivated by the well-established capacity of PDT photosensitizers to serve as tumour-selective fluorescence contrast agents, we demonstrate the capability of a consumer smartphone with low-cost add-ons to measure concentration-dependent PpIX fluorescence. This study lays the groundwork for the on-going development of image-guided ALA-PDT treatment technologies for global health applications. PMID:25965295

  8. Low-cost photodynamic therapy devices for global health settings: Characterization of battery-powered LED performance and smartphone imaging in 3D tumor models.

    PubMed

    Hempstead, Joshua; Jones, Dustin P; Ziouche, Abdelali; Cramer, Gwendolyn M; Rizvi, Imran; Arnason, Stephen; Hasan, Tayyaba; Celli, Jonathan P

    2015-05-12

    A lack of access to effective cancer therapeutics in resource-limited settings is implicated in global cancer health disparities between developed and developing countries. Photodynamic therapy (PDT) is a light-based treatment modality that has exhibited safety and efficacy in the clinic using wavelengths and irradiances achievable with light-emitting diodes (LEDs) operated on battery power. Here we assess low-cost enabling technology to extend the clinical benefit of PDT to regions with little or no access to electricity or medical infrastructure. We demonstrate the efficacy of a device based on a 635 nm high-output LED powered by three AA disposable alkaline batteries, to achieve strong cytotoxic response in monolayer and 3D cultures of A431 squamous carcinoma cells following photosensitization by administering aminolevulinic acid (ALA) to induce the accumulation of protoporphyrin IX (PpIX). Here we characterize challenges of battery-operated device performance, including battery drain and voltage stability specifically over relevant PDT dose parameters. Further motivated by the well-established capacity of PDT photosensitizers to serve as tumour-selective fluorescence contrast agents, we demonstrate the capability of a consumer smartphone with low-cost add-ons to measure concentration-dependent PpIX fluorescence. This study lays the groundwork for the on-going development of image-guided ALA-PDT treatment technologies for global health applications.

  9. Low-cost photodynamic therapy devices for global health settings: Characterization of battery-powered LED performance and smartphone imaging in 3D tumor models

    NASA Astrophysics Data System (ADS)

    Hempstead, Joshua; Jones, Dustin P.; Ziouche, Abdelali; Cramer, Gwendolyn M.; Rizvi, Imran; Arnason, Stephen; Hasan, Tayyaba; Celli, Jonathan P.

    2015-05-01

    A lack of access to effective cancer therapeutics in resource-limited settings is implicated in global cancer health disparities between developed and developing countries. Photodynamic therapy (PDT) is a light-based treatment modality that has exhibited safety and efficacy in the clinic using wavelengths and irradiances achievable with light-emitting diodes (LEDs) operated on battery power. Here we assess low-cost enabling technology to extend the clinical benefit of PDT to regions with little or no access to electricity or medical infrastructure. We demonstrate the efficacy of a device based on a 635 nm high-output LED powered by three AA disposable alkaline batteries, to achieve strong cytotoxic response in monolayer and 3D cultures of A431 squamous carcinoma cells following photosensitization by administering aminolevulinic acid (ALA) to induce the accumulation of protoporphyrin IX (PpIX). Here we characterize challenges of battery-operated device performance, including battery drain and voltage stability specifically over relevant PDT dose parameters. Further motivated by the well-established capacity of PDT photosensitizers to serve as tumour-selective fluorescence contrast agents, we demonstrate the capability of a consumer smartphone with low-cost add-ons to measure concentration-dependent PpIX fluorescence. This study lays the groundwork for the on-going development of image-guided ALA-PDT treatment technologies for global health applications.

  10. Low-cost photodynamic therapy devices for global health settings: Characterization of battery-powered LED performance and smartphone imaging in 3D tumor models

    PubMed Central

    Hempstead, Joshua; Jones, Dustin P.; Ziouche, Abdelali; Cramer, Gwendolyn M.; Rizvi, Imran; Arnason, Stephen; Hasan, Tayyaba; Celli, Jonathan P.

    2015-01-01

    A lack of access to effective cancer therapeutics in resource-limited settings is implicated in global cancer health disparities between developed and developing countries. Photodynamic therapy (PDT) is a light-based treatment modality that has exhibited safety and efficacy in the clinic using wavelengths and irradiances achievable with light-emitting diodes (LEDs) operated on battery power. Here we assess low-cost enabling technology to extend the clinical benefit of PDT to regions with little or no access to electricity or medical infrastructure. We demonstrate the efficacy of a device based on a 635 nm high-output LED powered by three AA disposable alkaline batteries, to achieve strong cytotoxic response in monolayer and 3D cultures of A431 squamous carcinoma cells following photosensitization by administering aminolevulinic acid (ALA) to induce the accumulation of protoporphyrin IX (PpIX). Here we characterize challenges of battery-operated device performance, including battery drain and voltage stability specifically over relevant PDT dose parameters. Further motivated by the well-established capacity of PDT photosensitizers to serve as tumour-selective fluorescence contrast agents, we demonstrate the capability of a consumer smartphone with low-cost add-ons to measure concentration-dependent PpIX fluorescence. This study lays the groundwork for the on-going development of image-guided ALA-PDT treatment technologies for global health applications. PMID:25965295

  11. Segmentation and detection of fluorescent 3D spots.

    PubMed

    Ram, Sundaresh; Rodríguez, Jeffrey J; Bosco, Giovanni

    2012-03-01

    The 3D spatial organization of genes and other genetic elements within the nucleus is important for regulating gene expression. Understanding how this spatial organization is established and maintained throughout the life of a cell is key to elucidating the many layers of gene regulation. Quantitative methods for studying nuclear organization will lead to insights into the molecular mechanisms that maintain gene organization as well as serve as diagnostic tools for pathologies caused by loss of nuclear structure. However, biologists currently lack automated and high throughput methods for quantitative and qualitative global analysis of 3D gene organization. In this study, we use confocal microscopy and fluorescence in-situ hybridization (FISH) as a cytogenetic technique to detect and localize the presence of specific DNA sequences in 3D. FISH uses probes that bind to specific targeted locations on the chromosomes, appearing as fluorescent spots in 3D images obtained using fluorescence microscopy. In this article, we propose an automated algorithm for segmentation and detection of 3D FISH spots. The algorithm is divided into two stages: spot segmentation and spot detection. Spot segmentation consists of 3D anisotropic smoothing to reduce the effect of noise, top-hat filtering, and intensity thresholding, followed by 3D region-growing. Spot detection uses a Bayesian classifier with spot features such as volume, average intensity, texture, and contrast to detect and classify the segmented spots as either true or false spots. Quantitative assessment of the proposed algorithm demonstrates improved segmentation and detection accuracy compared to other techniques.

  12. Global Evaluation of Prompt Dose Rates in ITER Using Hybrid Monte Carlo/Deterministic Techniques

    SciTech Connect

    Ibrahim, A.; Sawan, M.; Mosher, Scott W; Evans, Thomas M; Peplow, Douglas E.; Wilson, P.; Wagner, John C

    2011-01-01

    The hybrid Monte Carlo (MC)/deterministic techniques - Consistent Adjoint Driven Importance Sampling (CADIS) and Forward Weighted CADIS (FW-CADIS) - enable the full 3-D modeling of very large and complicated geometries. The ability of performing global MC calculations for nuclear parameters throughout the entire ITER reactor was demonstrated. The 2 m biological shield (bioshield) reduces the total prompt operational dose by six orders of magnitude. The divertor cryo-pump port results in a peaking factor of 120 in the prompt operational dose rate behind the bioshield by a factor of 47. The peak values of the prompt dose rates at the back surface of the bioshield were 240 uSv/hr and 94 uSv/hr corresponding to the regions behind the divertor cryo-pump port and the equatorial port, respectively.

  13. Europeana and 3D

    NASA Astrophysics Data System (ADS)

    Pletinckx, D.

    2011-09-01

    The current 3D hype creates a lot of interest in 3D. People go to 3D movies, but are we ready to use 3D in our homes, in our offices, in our communication? Are we ready to deliver real 3D to a general public and use interactive 3D in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real 3D of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering 3D content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create 3D learning objects, 3D tourist information or 3D scholarly communication. We are still in a prototype phase when it comes to integrate 3D objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, 3D has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable 3D objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.

  14. Hybrid and adaptive meta-model-based global optimization

    NASA Astrophysics Data System (ADS)

    Gu, J.; Li, G. Y.; Dong, Z.

    2012-01-01

    As an efficient and robust technique for global optimization, meta-model-based search methods have been increasingly used in solving complex and computation intensive design optimization problems. In this work, a hybrid and adaptive meta-model-based global optimization method that can automatically select appropriate meta-modelling techniques during the search process to improve search efficiency is introduced. The search initially applies three representative meta-models concurrently. Progress towards a better performing model is then introduced by selecting sample data points adaptively according to the calculated values of the three meta-models to improve modelling accuracy and search efficiency. To demonstrate the superior performance of the new algorithm over existing search methods, the new method is tested using various benchmark global optimization problems and applied to a real industrial design optimization example involving vehicle crash simulation. The method is particularly suitable for design problems involving computation intensive, black-box analyses and simulations.

  15. 3D Global PIC simulation of Alfvenic transition layers at the cusp outer boundary during IMF rotations from north to south

    NASA Astrophysics Data System (ADS)

    Cai, D. S.; Lembege, B.; Esmaeili, A.; Nishikawa, K.

    2013-12-01

    Statistical experimental observations of the cusp boundaries from CLUSTER mission made by Lavraud et al. (2005) have clearly evidenced the presence of a transition layer inside the magnetosheath near the outer boundary of the cusp. This layer characterized by Log(MA)~ 1 allows a transition from super-Alfvenic to sub-Alfvenic bulk flow from the exterior to the interior side of the outer cusp and has been mainly observed experimentally under northward interplanetary magnetic field (IMF). The role of this layer is important in order to understand the flow variations (and later the entry and precipitation of particles) when penetrating the outer boundary of the cusp. In order to analyze this layer, a large 3D PIC simulation of the global solar wind-terrestrial magnetosphere interaction have been performed, and the attention has been focused on the cusp region and its nearby surrounding during IMF rotation from north to south. Present results retrieve quite well the presence of this layer within the meridian plane for exactly northward IMF, but its location differs in the sense that it is located slightly below the X reconnection region associated to the nearby magnetopause (above the outer boundary of the cusp). In order to clarify this question, an extensive study has been performed as follows: (i) a 3D mapping of this transition layer in order to analyze more precisely the thickness, the location and the spatial extension of this layer on the magnetosphere flanks for a fixed Northward IMF configuration; (ii) a parametric study in order to analyze the impact of the IMF rotation from north to south on the persistence and the main features of this transition layer. The locations of this transition layer slightly radially expand and shrink during the IMF rotation and the thickness of the layer increases during the rotation. We show how these transition layers render the flow from super to sub Alfvenic and allow the particles enter into the magnetic cusp region. Alfven

  16. 3d-3d correspondence revisited

    NASA Astrophysics Data System (ADS)

    Chung, Hee-Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr

    2016-04-01

    In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d {N}=2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. We also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.

  17. 3d-3d correspondence revisited

    DOE PAGES

    Chung, Hee -Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr

    2016-04-21

    In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d N = 2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. As a result, we also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.

  18. Hybrid local FEM/global LISA modeling of guided wave propagation and interaction with damage in composite structures

    NASA Astrophysics Data System (ADS)

    Shen, Yanfeng; Cesnik, Carlos E. S.

    2015-03-01

    This paper presents a hybrid modeling technique for the efficient simulation of guided wave propagation and interaction with damage in composite structures. This hybrid approach uses a local finite element model (FEM) to compute the excitability of guided waves generated by piezoelectric transducers, while the global domain wave propagation, wave-damage interaction, and boundary reflections are modeled with the local interaction simulation approach (LISA). A small-size multi-physics FEM with non-reflective boundaries (NRB) was built to obtain the excitability information of guided waves generated by the transmitter. Frequency-domain harmonic analysis was carried out to obtain the solution for all the frequencies of interest. Fourier and inverse Fourier transform and frequency domain convolution techniques are used to obtain the time domain 3-D displacement field underneath the transmitter under an arbitrary excitation. This 3-D displacement field is then fed into the highly efficient time domain LISA simulation module to compute guided wave propagation, interaction with damage, and reflections at structural boundaries. The damping effect of composite materials was considered in the modified LISA formulation. The grids for complex structures were generated using commercial FEM preprocessors and converted to LISA connectivity format. Parallelization of the global LISA solution was achieved through Compute Unified Design Architecture (CUDA) running on Graphical Processing Unit (GPU). The multi-physics local FEM can reliably capture the detailed dimensions and local dynamics of the piezoelectric transducers. The global domain LISA can accurately solve the 3-D elastodynamic wave equations in a highly efficient manner. By combining the local FEM with global LISA, the efficient and accurate simulation of guided wave structural health monitoring procedure is achieved. Two numerical case studies are presented: (1) wave propagation in a unidirectional CFRP composite plate

  19. Self consistent particles dynamics in/out of the cusp region by using back tracking technics; a global 3D PIC simulation approach

    NASA Astrophysics Data System (ADS)

    Esmaeili, A.; Cai, D.; Lembege, B.; Nishikawa, K.

    2013-12-01

    Large scale three dimensionbal PIC (particle in cell) simulations are presently used in order to analyze the global solar wind-terrestrial magnetosphere intreraction within a full self-consistent approach, and where both electrons and ions are treated as an assembly of individual particles. This 3D kinetic approach allows us to analyze in particular the dynamics and the fine structures of the cusp region when including self consistently not only its whole neighborhood (in the terrestrial magnetosphere) but also the impact of the solar wind and the interplanetary field (IMF) features. Herein, we focuss our attention on the cusp region and in particular on the acceleration and precipitation of particles (both ions and electrons) within the cusp. In present simulations, the IMF is chosen northward, (i.e. where the X -reconnection region is just above the cusp, in the meridian plane). Back-trackings of self-consistent particles are analyzed in details in order to determine (i) which particles (just above the cusp) are precipitated deeply into the cusp, (ii) which populations are injected from the cusp into the nearby tail, (iii) where the particles suffer the largest energisation along their self-consistent trajectories, (iv) where these populations accumulate, and (v) where the most energetic particles are originally coming from. This approach allows to make a traking of particles within the scenario "solar wind-magnetosheath- cusp -nearbytail"; moreover it strongly differs from the standard test particles technics and allows to provide informations not accessible when using full MHD approach. Keywords: Tracing Particles, Particle In Cell (PIC) simulation, double cusp, test particles method, IMF, Solar wind, Magnetosphere

  20. Creating and Using Interactive, 3D-Printed Models to Improve Student Comprehension of the Bohr Model of the Atom, Bond Polarity, and Hybridization

    ERIC Educational Resources Information Center

    Smiar, Karen; Mendez, J. D.

    2016-01-01

    Molecular model kits have been used in chemistry classrooms for decades but have seen very little recent innovation. Using 3D printing, three sets of physical models were created for a first semester, introductory chemistry course. Students manipulated these interactive models during class activities as a supplement to existing teaching tools for…

  1. 3D and Education

    NASA Astrophysics Data System (ADS)

    Meulien Ohlmann, Odile

    2013-02-01

    Today the industry offers a chain of 3D products. Learning to "read" and to "create in 3D" becomes an issue of education of primary importance. 25 years professional experience in France, the United States and Germany, Odile Meulien set up a personal method of initiation to 3D creation that entails the spatial/temporal experience of the holographic visual. She will present some different tools and techniques used for this learning, their advantages and disadvantages, programs and issues of educational policies, constraints and expectations related to the development of new techniques for 3D imaging. Although the creation of display holograms is very much reduced compared to the creation of the 90ies, the holographic concept is spreading in all scientific, social, and artistic activities of our present time. She will also raise many questions: What means 3D? Is it communication? Is it perception? How the seeing and none seeing is interferes? What else has to be taken in consideration to communicate in 3D? How to handle the non visible relations of moving objects with subjects? Does this transform our model of exchange with others? What kind of interaction this has with our everyday life? Then come more practical questions: How to learn creating 3D visualization, to learn 3D grammar, 3D language, 3D thinking? What for? At what level? In which matter? for whom?

  2. Quantifying floral shape variation in 3D using microcomputed tomography: a case study of a hybrid line between actinomorphic and zygomorphic flowers

    PubMed Central

    Wang, Chun-Neng; Hsu, Hao-Chun; Wang, Cheng-Chun; Lee, Tzu-Kuei; Kuo, Yan-Fu

    2015-01-01

    The quantification of floral shape variations is difficult because flower structures are both diverse and complex. Traditionally, floral shape variations are quantified using the qualitative and linear measurements of two-dimensional (2D) images. The 2D images cannot adequately describe flower structures, and thus lead to unsatisfactory discrimination of the flower shape. This study aimed to acquire three-dimensional (3D) images by using microcomputed tomography (μCT) and to examine the floral shape variations by using geometric morphometrics (GM). To demonstrate the advantages of the 3D-μCT-GM approach, we applied the approach to a second-generation population of florist's gloxinia (Sinningia speciosa) crossed from parents of zygomorphic and actinomorphic flowers. The flowers in the population considerably vary in size and shape, thereby served as good materials to test the applicability of the proposed phenotyping approach. Procedures were developed to acquire 3D volumetric flower images using a μCT scanner, to segment the flower regions from the background, and to select homologous characteristic points (i.e., landmarks) from the flower images for the subsequent GM analysis. The procedures identified 95 landmarks for each flower and thus improved the capability of describing and illustrating the flower shapes, compared with typically lower number of landmarks in 2D analyses. The GM analysis demonstrated that flower opening and dorsoventral symmetry were the principal shape variations of the flowers. The degrees of flower opening and corolla asymmetry were then subsequently quantified directly from the 3D flower images. The 3D-μCT-GM approach revealed shape variations that could not be identified using typical 2D approaches and accurately quantified the flower traits that presented a challenge in 2D images. The approach opens new avenues to investigate floral shape variations. PMID:26442038

  3. An effective hyper-resolution pseudo-3D implementation of small scale hydrological features to improve regional and global climate studies

    NASA Astrophysics Data System (ADS)

    Hazenberg, P.; Broxton, P. D.; Gochis, D. J.; Niu, G.; Pelletier, J. D.; Troch, P. A.; Zeng, X.

    2013-12-01

    Global land surface processes play an important role in the land-atmosphere exchanges of energy, water, and trace gases. As such, correct representation of the different hydrological processes has long been an important research topic in climate modeling. Historically, these processes were presented at a relatively coarse horizontal resolution, focusing mainly on the vertical hydrological response, while lateral exchanges were either disregarded or implemented in a relatively crude manner. Increases in computational power have led to higher resolution regional and global land surface models. For the coming years, it is anticipated that these models will simulate the hydrological response of the earth surface at a 100-1000 meter pixel size, which is stated as hyper-resolution earth surface modeling. At these relatively high resolutions, correct representation of groundwater, including lateral interactions across pixels and with the channel network, becomes important. Next to that, at these high resolutions elevation differences have a larger impact on the hydrological response and therefore need to be represented properly. We will present a new hydrological framework specifically developed to operate at these hyper-resolutions. Our new approach discriminates between differences in the hydrological response of hillslopes, riparian zones, wetlands and flat regions within a given pixel, while interacting with the channel network and the atmosphere. Instead of applying the traditional conceptual approach, these interactions are incorporated using a physically-based approach. In order to be able to differentiate between these different hydrological features, globally available high-resolution 30 meter DEM data were analyzed using a state-of-the-art digital geomorphological identification method. Based on these techniques, local estimates of soil depth, hillslope width functions, channel network density, etc. were also obtained that are used as input to the model In the

  4. A Novel Hybrid Firefly Algorithm for Global Optimization

    PubMed Central

    Zhang, Lina; Liu, Liqiang; Yang, Xin-She; Dai, Yuntao

    2016-01-01

    Global optimization is challenging to solve due to its nonlinearity and multimodality. Traditional algorithms such as the gradient-based methods often struggle to deal with such problems and one of the current trends is to use metaheuristic algorithms. In this paper, a novel hybrid population-based global optimization algorithm, called hybrid firefly algorithm (HFA), is proposed by combining the advantages of both the firefly algorithm (FA) and differential evolution (DE). FA and DE are executed in parallel to promote information sharing among the population and thus enhance searching efficiency. In order to evaluate the performance and efficiency of the proposed algorithm, a diverse set of selected benchmark functions are employed and these functions fall into two groups: unimodal and multimodal. The experimental results show better performance of the proposed algorithm compared to the original version of the firefly algorithm (FA), differential evolution (DE) and particle swarm optimization (PSO) in the sense of avoiding local minima and increasing the convergence rate. PMID:27685869

  5. Global hybrid simulations: foreshock and bow shock morphology

    NASA Astrophysics Data System (ADS)

    Blanco-Cano, Xochitl; Omidi, Nojan; Russell, Christopher

    The solar wind interaction with earth's magnetosphere is mediated by the formation of a bow shock. Ahead of this shock a foreshock forms. Global hybrid simulations have proven to be very useful to study these complex regions, where kinetic effects play a major role in dissipation process and largely affect the large scale dynamics of the foreshock-bow shock-magnetosheath system. In this work we use global hybrid simulations to study solar wind coupling with the magnetosphere for oblique (45° ) and radial IMF geometries. We find that the foreshock morphology changes drastically from one case to the other. We study ULF waves' properties, evolution, and their impact on the quasi-parallel shock. We also investigate differences in suprathermal ion distributions under the two geometries and relate this to wave origin. We find that under the radial geometry the foreshock is permeated also by density cavities that are not clear for the oblique interaction. We discuss the properties of these cavities and their impact on the quasi-parallel bow shock. We also relate simulation cavities to observations in earth's foreshock.

  6. Hybrid 3-D rocket trajectory program. Part 1: Formulation and analysis. Part 2: Computer programming and user's instruction. [computerized simulation using three dimensional motion analysis

    NASA Technical Reports Server (NTRS)

    Huang, L. C. P.; Cook, R. A.

    1973-01-01

    Models utilizing various sub-sets of the six degrees of freedom are used in trajectory simulation. A 3-D model with only linear degrees of freedom is especially attractive, since the coefficients for the angular degrees of freedom are the most difficult to determine and the angular equations are the most time consuming for the computer to evaluate. A computer program is developed that uses three separate subsections to predict trajectories. A launch rail subsection is used until the rocket has left its launcher. The program then switches to a special 3-D section which computes motions in two linear and one angular degrees of freedom. When the rocket trims out, the program switches to the standard, three linear degrees of freedom model.

  7. Global Hybrid Simulations: Applications to Bow Shock and Dayside Magnetosphere

    NASA Astrophysics Data System (ADS)

    Omidi, Nojan; Sibeck, David; Phan, Tai; Eastwood, Jonathan

    With the advent of global hybrid (kinetic ions, fluid electrons) simulations it has become possible to examine magnetospheric processes and their interconnections on ion time and spatial scales. This capability combined with multi-spacecraft missions such as Cluster and THEMIS provide an unprecedented opportunity to perform detailed, quantitative comparisons between theory and observations to examine basic paradigms and build new ones. To illustrate this capability, this presentation focuses on a number of topics related to the bow shock and dayside magnetosphere. One topic concerns the formation of the ion foreshock boundary predicted by global hybrid simulations and their relationship to the observed phenomenon of foreshock cavities. Interaction of solar wind discontinuities with the bow shock lead to a variety of phenomena such as hot flow anomalies (HFAs) or initiation of magnetic reconnection in the magnetosheath. We show examples of both processes in hybrid simulations and comparisons with spacecraft observations. In regards to HFAs, recent THEMIS measurements provide detailed information on their magnetosheath signatures. Understanding of these signatures and impacts on the magnetosphere/ionosphere system remains an important topic of investigation. Magnetic reconnection in the magnetosheath provides an opportunity to examine this important process in relative isolation and symmetric plasma conditions. Here, we address the impact of discontinuity thickness and magnetic shear on the nature of the resulting reconnection and the implications for time dependency and geometry (anti-parallel vs component) of reconnection at the magnetopause. The final topic of the presentation is the formation of flux transfer events (FTEs) at the magnetopause and their subsequent motion and interaction with the cusps. This interaction involves secondary magnetic reconnection and acceleration of plasma into the cusp. As we illustrate, this process may account for the formation of

  8. Design of the 1.5 MW, 30-96 MHz ultra-wideband 3 dB high power hybrid coupler for Ion Cyclotron Resonance Frequency (ICRF) heating in fusion grade reactor

    NASA Astrophysics Data System (ADS)

    Yadav, Rana Pratap; Kumar, Sunil; Kulkarni, S. V.

    2016-01-01

    Design and developmental procedure of strip-line based 1.5 MW, 30-96 MHz, ultra-wideband high power 3 dB hybrid coupler has been presented and its applicability in ion cyclotron resonance heating (ICRH) in tokamak is discussed. For the high power handling capability, spacing between conductors and ground need to very high. Hence other structural parameters like strip-width, strip thickness coupling gap, and junction also become large which can be gone upto optimum limit where various constrains like fabrication tolerance, discontinuities, and excitation of higher TE and TM modes become prominent and significantly deteriorates the desired parameters of the coupled lines system. In designed hybrid coupler, two 8.34 dB coupled lines are connected in tandem to get desired coupling of 3 dB and air is used as dielectric. The spacing between ground and conductors are taken as 0.164 m for 1.5 MW power handling capability. To have the desired spacing, each of 8.34 dB segments are designed with inner dimension of 3.6 × 1.0 × 40 cm where constraints have been significantly realized, compensated, and applied in designing of 1.5 MW hybrid coupler and presented in paper.

  9. Design of the 1.5 MW, 30-96 MHz ultra-wideband 3 dB high power hybrid coupler for Ion Cyclotron Resonance Frequency (ICRF) heating in fusion grade reactor.

    PubMed

    Yadav, Rana Pratap; Kumar, Sunil; Kulkarni, S V

    2016-01-01

    Design and developmental procedure of strip-line based 1.5 MW, 30-96 MHz, ultra-wideband high power 3 dB hybrid coupler has been presented and its applicability in ion cyclotron resonance heating (ICRH) in tokamak is discussed. For the high power handling capability, spacing between conductors and ground need to very high. Hence other structural parameters like strip-width, strip thickness coupling gap, and junction also become large which can be gone upto optimum limit where various constrains like fabrication tolerance, discontinuities, and excitation of higher TE and TM modes become prominent and significantly deteriorates the desired parameters of the coupled lines system. In designed hybrid coupler, two 8.34 dB coupled lines are connected in tandem to get desired coupling of 3 dB and air is used as dielectric. The spacing between ground and conductors are taken as 0.164 m for 1.5 MW power handling capability. To have the desired spacing, each of 8.34 dB segments are designed with inner dimension of 3.6 × 1.0 × 40 cm where constraints have been significantly realized, compensated, and applied in designing of 1.5 MW hybrid coupler and presented in paper.

  10. Strong light scattering and broadband (UV to IR) photoabsorption in stretchable 3D hybrid architectures based on Aerographite decorated by ZnO nanocrystallites.

    PubMed

    Tiginyanu, Ion; Ghimpu, Lidia; Gröttrup, Jorit; Postolache, Vitalie; Mecklenburg, Matthias; Stevens-Kalceff, Marion A; Ursaki, Veaceslav; Payami, Nader; Feidenhansl, Robert; Schulte, Karl; Adelung, Rainer; Mishra, Yogendra Kumar

    2016-09-12

    In present work, the nano- and microscale tetrapods from zinc oxide were integrated on the surface of Aerographite material (as backbone) in carbon-metal oxide hybrid hierarchical network via a simple and single step magnetron sputtering process. The fabricated hybrid networks are characterized for morphology, microstructural and optical properties. The cathodoluminescence investigations revealed interesting luminescence features related to carbon impurities and inherent host defects in zinc oxide. Because of the wide bandgap of zinc oxide and its intrinsic defects, the hybrid network absorbs light in the UV and visible regions, however, this broadband photoabsorption behavior extends to the infrared (IR) region due to the dependence of the optical properties of ZnO architectures upon size and shape of constituent nanostructures and their doping by carbon impurities. Such a phenomenon of broadband photoabsorption ranging from UV to IR for zinc oxide based hybrid materials is novel. Additionally, the fabricated network exhibits strong visible light scattering behavior. The developed Aerographite/nanocrystalline ZnO hybrid network materials, equipped with broadband photoabsorption and strong light scattering, are very promising candidates for optoelectronic technologies.

  11. Strong light scattering and broadband (UV to IR) photoabsorption in stretchable 3D hybrid architectures based on Aerographite decorated by ZnO nanocrystallites.

    PubMed

    Tiginyanu, Ion; Ghimpu, Lidia; Gröttrup, Jorit; Postolache, Vitalie; Mecklenburg, Matthias; Stevens-Kalceff, Marion A; Ursaki, Veaceslav; Payami, Nader; Feidenhansl, Robert; Schulte, Karl; Adelung, Rainer; Mishra, Yogendra Kumar

    2016-01-01

    In present work, the nano- and microscale tetrapods from zinc oxide were integrated on the surface of Aerographite material (as backbone) in carbon-metal oxide hybrid hierarchical network via a simple and single step magnetron sputtering process. The fabricated hybrid networks are characterized for morphology, microstructural and optical properties. The cathodoluminescence investigations revealed interesting luminescence features related to carbon impurities and inherent host defects in zinc oxide. Because of the wide bandgap of zinc oxide and its intrinsic defects, the hybrid network absorbs light in the UV and visible regions, however, this broadband photoabsorption behavior extends to the infrared (IR) region due to the dependence of the optical properties of ZnO architectures upon size and shape of constituent nanostructures and their doping by carbon impurities. Such a phenomenon of broadband photoabsorption ranging from UV to IR for zinc oxide based hybrid materials is novel. Additionally, the fabricated network exhibits strong visible light scattering behavior. The developed Aerographite/nanocrystalline ZnO hybrid network materials, equipped with broadband photoabsorption and strong light scattering, are very promising candidates for optoelectronic technologies. PMID:27616632

  12. Strong light scattering and broadband (UV to IR) photoabsorption in stretchable 3D hybrid architectures based on Aerographite decorated by ZnO nanocrystallites

    PubMed Central

    Tiginyanu, Ion; Ghimpu, Lidia; Gröttrup, Jorit; Postolache, Vitalie; Mecklenburg, Matthias; Stevens-Kalceff, Marion A.; Ursaki, Veaceslav; Payami, Nader; Feidenhansl, Robert; Schulte, Karl; Adelung, Rainer; Mishra, Yogendra Kumar

    2016-01-01

    In present work, the nano- and microscale tetrapods from zinc oxide were integrated on the surface of Aerographite material (as backbone) in carbon-metal oxide hybrid hierarchical network via a simple and single step magnetron sputtering process. The fabricated hybrid networks are characterized for morphology, microstructural and optical properties. The cathodoluminescence investigations revealed interesting luminescence features related to carbon impurities and inherent host defects in zinc oxide. Because of the wide bandgap of zinc oxide and its intrinsic defects, the hybrid network absorbs light in the UV and visible regions, however, this broadband photoabsorption behavior extends to the infrared (IR) region due to the dependence of the optical properties of ZnO architectures upon size and shape of constituent nanostructures and their doping by carbon impurities. Such a phenomenon of broadband photoabsorption ranging from UV to IR for zinc oxide based hybrid materials is novel. Additionally, the fabricated network exhibits strong visible light scattering behavior. The developed Aerographite/nanocrystalline ZnO hybrid network materials, equipped with broadband photoabsorption and strong light scattering, are very promising candidates for optoelectronic technologies. PMID:27616632

  13. Strong light scattering and broadband (UV to IR) photoabsorption in stretchable 3D hybrid architectures based on Aerographite decorated by ZnO nanocrystallites

    NASA Astrophysics Data System (ADS)

    Tiginyanu, Ion; Ghimpu, Lidia; Gröttrup, Jorit; Postolache, Vitalie; Mecklenburg, Matthias; Stevens-Kalceff, Marion A.; Ursaki, Veaceslav; Payami, Nader; Feidenhansl, Robert; Schulte, Karl; Adelung, Rainer; Mishra, Yogendra Kumar

    2016-09-01

    In present work, the nano- and microscale tetrapods from zinc oxide were integrated on the surface of Aerographite material (as backbone) in carbon-metal oxide hybrid hierarchical network via a simple and single step magnetron sputtering process. The fabricated hybrid networks are characterized for morphology, microstructural and optical properties. The cathodoluminescence investigations revealed interesting luminescence features related to carbon impurities and inherent host defects in zinc oxide. Because of the wide bandgap of zinc oxide and its intrinsic defects, the hybrid network absorbs light in the UV and visible regions, however, this broadband photoabsorption behavior extends to the infrared (IR) region due to the dependence of the optical properties of ZnO architectures upon size and shape of constituent nanostructures and their doping by carbon impurities. Such a phenomenon of broadband photoabsorption ranging from UV to IR for zinc oxide based hybrid materials is novel. Additionally, the fabricated network exhibits strong visible light scattering behavior. The developed Aerographite/nanocrystalline ZnO hybrid network materials, equipped with broadband photoabsorption and strong light scattering, are very promising candidates for optoelectronic technologies.

  14. Study of energy transfer from the solar wind to Earth's magnetosphere using the 3D- MHD BATS-R-US global model

    NASA Astrophysics Data System (ADS)

    Jauer, P. R.; Gonzalez, W. D.; de Souza Costa, C. L.; Souza, V. M.

    2013-12-01

    The interaction, transport and conversion of energy between the solar wind and Earth's magnetosphere have been studied for decades through in situ measurements and Magnetohydrodynamics simulation, (MHD). Nevertheless, due to the vast regions of space and nonlinearities of the physical processes there are many questions that still remain without conclusive answers. Currently, the MHD simulation is a powerful tool that helps other means of already existing research, even within its theoretical limitation; it provides information of the space regions where in situ measurements are rare or nonexistent. The aim of this work is the study of energy transfer from the solar wind through the calculation of the divergence of the Poynting vector for the inner regions of the Earth's magnetosphere, especially the magneto tail using 3D global MHD numerical code Space Weather Modelling Framework (SWMF) / (Block Adaptive Tree Solar wind Roe Upwind Scheme) (BATS-R-US), developed by the University of Michigan. We conducted a simulation study for the event that occurred on September 21-27, 1999, for which the peak value of the interplanetary magnetic field was -22 nT, and gave rise to an intense magnetic storm with peak Dst of -160 nT. Furthermore, we compare the results of the power estimated by the model - through the integration of the Poynting vector in rectangular region of the tail, with a domain -130

  15. 3D Imaging.

    ERIC Educational Resources Information Center

    Hastings, S. K.

    2002-01-01

    Discusses 3 D imaging as it relates to digital representations in virtual library collections. Highlights include X-ray computed tomography (X-ray CT); the National Science Foundation (NSF) Digital Library Initiatives; output peripherals; image retrieval systems, including metadata; and applications of 3 D imaging for libraries and museums. (LRW)

  16. Converting 2D inorganic-organic ZnSe-DETA hybrid nanosheets into 3D hierarchical nanosheet-based ZnSe microspheres with enhanced visible-light-driven photocatalytic performances

    NASA Astrophysics Data System (ADS)

    Wu, Xuan; Xu, Rui; Zhu, Rongjiao; Wu, Rui; Zhang, Bin

    2015-05-01

    Engineering two-dimensional (2D) nanosheets into three-dimensional (3D) hierarchical structures is one of the great challenges in nanochemistry and materials science. We report a facile and simple chemical conversion route to fabricate 3D hierarchical nanosheet-based ZnSe microspheres by using 2D inorganic-organic hybrid ZnSe-DETA (DETA = diethylenetriamine) nanosheets as the starting precursors. The conversion mechanism involves the controlled depletion of the organic-component (DETA) from the hybrid precursors and the subsequent self-assembly of the remnant inorganic-component (ZnSe). The transformation reaction of ZnSe-DETA nanosheets is mainly influenced by the concentration of DETA in the reaction solution. We demonstrated that this organic-component depletion method could be extended to the synthesis of other hierarchical structures of metal sulfides. In addition, the obtained hierarchical nanosheet-based ZnSe microspheres exhibited outstanding performance in visible light photocatalytic degradation of methyl orange and were highly active for photocatalytic H2 production.Engineering two-dimensional (2D) nanosheets into three-dimensional (3D) hierarchical structures is one of the great challenges in nanochemistry and materials science. We report a facile and simple chemical conversion route to fabricate 3D hierarchical nanosheet-based ZnSe microspheres by using 2D inorganic-organic hybrid ZnSe-DETA (DETA = diethylenetriamine) nanosheets as the starting precursors. The conversion mechanism involves the controlled depletion of the organic-component (DETA) from the hybrid precursors and the subsequent self-assembly of the remnant inorganic-component (ZnSe). The transformation reaction of ZnSe-DETA nanosheets is mainly influenced by the concentration of DETA in the reaction solution. We demonstrated that this organic-component depletion method could be extended to the synthesis of other hierarchical structures of metal sulfides. In addition, the obtained

  17. Global warming induced hybrid rainy seasons in the Sahel

    NASA Astrophysics Data System (ADS)

    Salack, Seyni; Klein, Cornelia; Giannini, Alessandra; Sarr, Benoit; Worou, Omonlola N.; Belko, Nouhoun; Bliefernicht, Jan; Kunstman, Harald

    2016-10-01

    The small rainfall recovery observed over the Sahel, concomitant with a regional climate warming, conceals some drought features that exacerbate food security. The new rainfall features include false start and early cessation of rainy seasons, increased frequency of intense daily rainfall, increasing number of hot nights and warm days and a decreasing trend in diurnal temperature range. Here, we explain these mixed dry/wet seasonal rainfall features which are called hybrid rainy seasons by delving into observed data consensus on the reduction in rainfall amount, its spatial coverage, timing and erratic distribution of events, and other atmospheric variables crucial in agro-climatic monitoring and seasonal forecasting. Further composite investigations of seasonal droughts, oceans warming and the regional atmospheric circulation nexus reveal that the low-to-mid-level atmospheric winds pattern, often stationary relative to either strong or neutral El-Niño-Southern-Oscillations drought patterns, associates to basin warmings in the North Atlantic and the Mediterranean Sea to trigger hybrid rainy seasons in the Sahel. More challenging to rain-fed farming systems, our results suggest that these new rainfall conditions will most likely be sustained by global warming, reshaping thereby our understanding of food insecurity in this region.

  18. Ultra-long Pt nanolawns supported on TiO2-coated carbon fibers as 3D hybrid catalyst for methanol oxidation

    PubMed Central

    2012-01-01

    In this study, TiO2 thin film photocatalyst on carbon fibers was used to synthesize ultra-long single crystalline Pt nanowires via a simple photoreduction route (thermally activated photoreduction). It also acted as a co-catalytic material with Pt. Taking advantage of the high-aspect ratio of the Pt nanostructure as well as the excellent catalytic activity of TiO2, this hybrid structure has the great potential as the active anode in direct methanol fuel cells. The electrochemical results indicate that TiO2 is capable of transforming CO-like poisoning species on the Pt surface during methanol oxidation and contributes to a high CO tolerance of this Pt nanowire/TiO2 hybrid structure. PMID:22546416

  19. Novel utilization of 3D technology and the hybrid operating theatre: Peri-operative assessment of posterior sterno-clavicular dislocation using cone beam CT

    SciTech Connect

    Crowhurst, James A; Campbell, Douglas; Whitby, Mark; Pathmanathan, Pavthrun

    2013-06-15

    A patient with a medial and posterior dislocation of the right sterno-clavicular (SC) joint and displacement of the trachea and brachiocephalic artery by the medial head of the clavicle underwent general anaesthetic in the operating theatre for an open reduction procedure. The surgeon initially attempted a closed reduction, but this required imaging to check SC alignment. The patient was transferred to an adjacent hybrid operating theatre for imaging. Cone beam computed tomography (CBCT) was performed, which successfully demonstrated a significant reduction in the dislocation of the SC joint. The trachea and brachiocephalic artery were no longer compressed or displaced. This case study demonstrates an alternative to the patient being transferred to the medical imaging department for multi-slice CT. It also describes a novel use of the hybrid operating theatre and its CBCT capabilities.

  20. 3D TiO2@Ni(OH)2 Core-shell Arrays with Tunable Nanostructure for Hybrid Supercapacitor Application

    PubMed Central

    Ke, Qingqing; Zheng, Minrui; Liu, Huajun; Guan, Cao; Mao, Lu; Wang, John

    2015-01-01

    Three dimensional hierarchical nanostructures have attracted great attention for electrochemical energy storage applications. In this work, self-supported TiO2@Ni(OH)2 core-shell nanowire arrays are prepared on carbon fiber paper via the combination of hydrothermal synthesis and chemical bath deposition. In this core-shell hybrid, the morphology and wall size of the interconnected nanoflake shell of Ni(OH)2 can be tuned through adjusting the concentration of ammonia solution. Heterogeneous nucleation and subsequent oriented crystal growth are identified to be the synthesis mechanism affecting the nanostructure of the shell material, which consequently determines the electrochemical performance in both energy storage and charge transfer. Superior capabilities of 264 mAhg−1 at 1 A g−1 and 178 mAh g−1 at 10 A g−1 are achieved with the core-shell hybrids of the optimized structure. The asymmetric supercapacitor prototype, comprising of TiO2@Ni(OH)2 as the anode and mesoporous carbons (MCs) as the cathode, is shown to exhibit superior electrochemical performance with high energy and power densities. The present work provides a clear illustration of the structure-property relationship in nanocrystal synthesis and offers a potential strategy to enhance the battery type Ni(OH)2 electrode in a hybrid supercapacitor device. PMID:26353970

  1. The Interaction of the Solar Wind with Solar Probe Plus - 3D Hybrid Simulation. Report 2: The Study for the Distance 9.5Rs

    NASA Technical Reports Server (NTRS)

    Lipatov, Alexander S.; Sittler, Edward C.; Hartle, Richard E.; Cooper, John F.

    2010-01-01

    Our paper is a 2.5D and 3D numerical plasma models of the interaction of the solar wind (SW) with the Solar Probe Plus spacecraft (SPPSC). These results should be interpreted as a basic plasma model for which the derived SW interaction with spacecraft (SC) could have consequences for both plasma wave and electron plasma measurements on board SC in the inner heliosphere. We observe an excitation of the low frequency Alfven and whistler type wave directed by the magnetic field with an amplitude of the electromagnetic field oscillation about of (0.015-0.06) V/m. The compression waves and the jumps in an electric field with an amplitude of about 1.5 V/m and (12-18) V/m were also observed. The observed strong electromagnetic perturbations may be a crucial point in the electromagnetic measurements, which were planned in future Solar Probe Plus mission.

  2. Time-dependent distribution functions and resulting synthetic NPA spectra in C-Mod calculated with the CQL3D-Hybrid-FOW, AORSA full-wave, and DC Lorentz codes

    NASA Astrophysics Data System (ADS)

    Harvey, R. W.; Petrov, Yu.; Jaeger, E. F.; Berry, L. A.; Bonoli, P. T.; Bader, A.

    2015-12-01

    A time-dependent simulation of C-Mod pulsed TCRF power is made obtaining minority hydrogen ion distributions with the CQL3D-Hybrid-FOW finite-orbit-width Fokker-Planck code. Cyclotron-resonant TCRF fields are calculated with the AORSA full wave code. The RF diffusion coefficients used in CQL3D are obtained with the DC Lorentz gyro-orbit code for perturbed particle trajectories in the combined equilibrium and TCRF electromagnetic fields. Prior results with a zero-banana-width simulation using the CQL3D/AORSA/DC time-cycles showed a pronounced enhancement of the H distribution in the perpendicular velocity direction compared to results obtained from Stix's quasilinear theory, and this substantially increased the rampup rate of the observed vertically-viewed neutral particle analyzer (NPA) flux, in general agreement with experiment. However, ramp down of the NPA flux after the pulse, remained long compared to the experiment. The present study compares the new FOW results, including relevant gyro-radius effects, to determine the importance of these new effects on the the NPA time-dependence.

  3. Converting 2D inorganic-organic ZnSe-DETA hybrid nanosheets into 3D hierarchical nanosheet-based ZnSe microspheres with enhanced visible-light-driven photocatalytic performances.

    PubMed

    Wu, Xuan; Xu, Rui; Zhu, Rongjiao; Wu, Rui; Zhang, Bin

    2015-06-01

    Engineering two-dimensional (2D) nanosheets into three-dimensional (3D) hierarchical structures is one of the great challenges in nanochemistry and materials science. We report a facile and simple chemical conversion route to fabricate 3D hierarchical nanosheet-based ZnSe microspheres by using 2D inorganic-organic hybrid ZnSe-DETA (DETA = diethylenetriamine) nanosheets as the starting precursors. The conversion mechanism involves the controlled depletion of the organic-component (DETA) from the hybrid precursors and the subsequent self-assembly of the remnant inorganic-component (ZnSe). The transformation reaction of ZnSe-DETA nanosheets is mainly influenced by the concentration of DETA in the reaction solution. We demonstrated that this organic-component depletion method could be extended to the synthesis of other hierarchical structures of metal sulfides. In addition, the obtained hierarchical nanosheet-based ZnSe microspheres exhibited outstanding performance in visible light photocatalytic degradation of methyl orange and were highly active for photocatalytic H2 production.

  4. Global 3-D imaging of mantle electrical conductivity based on inversion of observatory C-responses - I. An approach and its verification

    NASA Astrophysics Data System (ADS)

    Kuvshinov, Alexey; Semenov, Alexey

    2012-06-01

    We present a novel frequency-domain inverse solution to recover the 3-D electrical conductivity distribution in the mantle. The solution is based on analysis of local C-responses. It exploits an iterative gradient-type method - limited-memory quasi-Newton method - for minimizing the penalty function consisting of data misfit and regularization terms. The integral equation code is used as a forward engine to calculate responses and data misfit gradients during inversion. An adjoint approach is implemented to compute misfit gradients efficiently. Further improvements in computational load come from parallelizing the scheme with respect to frequencies, and from setting the most time-consuming part of the forward calculations - calculation of Green's tensors - apart from the inversion loop. Convergence, performance, and accuracy of our 3-D inverse solution are demonstrated with a synthetic numerical example. A companion paper applies the strategy set forth here to real data.

  5. 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.

  6. Nano-spatial parameters from 3D to 2D lattice dimensionality by organic variant in [ZnCl4]- [R]+ hybrid materials: Structure, architecture-lattice dimensionality, microscopy, optical Eg and PL correlations

    NASA Astrophysics Data System (ADS)

    Kumar, Ajit; Verma, Sanjay K.; Alvi, P. A.; Jasrotia, Dinesh

    2016-04-01

    The nanospatial morphological features of [ZnCl]- [C5H4NCH3]+ hybrid derivative depicts 28 nm granular size and 3D spreader shape packing pattern as analyzed by FESEM and single crystal XRD structural studies. The organic moiety connect the inorganic components through N-H+…Cl- hydrogen bond to form a hybrid composite, the replacement of organic derivatives from 2-methylpyridine to 2-Amino-5-choloropyridine results the increase in granular size from 28nm to 60nm and unit cell packing pattern from 3D-2D lattice dimensionality along ac plane. The change in optical energy direct band gap value from 3.01eV for [ZnCl]- [C5H4NCH3]+ (HM1) to 3.42eV for [ZnCl]- [C5H5ClN2]+ (HM2) indicates the role of organic moiety in optical properties of hybrid materials. The photoluminescence emission spectra is observed in the wavelength range of 370 to 600 nm with maximum peak intensity of 9.66a.u. at 438 nm for (HM1) and 370 to 600 nm with max peak intensity of 9.91 a.u. at 442 nm for (HM2), indicating that the emission spectra lies in visible range. PL excitation spectra depicts the maximum excitation intensity [9.8] at 245.5 nm for (HM1) and its value of 9.9 a.u. at 294 nm, specify the excitation spectra lies in UV range. Photoluminescence excitation spectra is observed in the wavelength range of 280 to 350 nm with maximum peak intensity of 9.4 a.u. at 285.5 nm and 9.9 a.u. at 294 and 297 nm, indicating excitation in the UV spectrum. Single crystal growth process and detailed physiochemical characterization such as XRD, FESEM image analysis photoluminescence property reveals the structure stability with non-covalent interactions, lattice dimensionality (3D-2D) correlations interweaving into the design of inorganic-organic hybrid materials.

  7. An efficient hybrid MLFMA-FFT solver for the volume integral equation in case of sparse 3D inhomogeneous dielectric scatterers

    SciTech Connect

    Zaeytijd, J. de Bogaert, I.; Franchois, A.

    2008-07-01

    Electromagnetic scattering problems involving inhomogeneous objects can be numerically solved by applying a Method of Moments discretization to the volume integral equation. For electrically large problems, the iterative solution of the resulting linear system is expensive, both computationally and in memory use. In this paper, a hybrid MLFMA-FFT method is presented, which combines the fast Fourier transform (FFT) method and the High Frequency Multilevel Fast Multipole Algorithm (MLFMA) in order to reduce the cost of the matrix-vector multiplications needed in the iterative solver. The method represents the scatterers within a set of possibly disjoint identical cubic subdomains, which are meshed using a uniform cubic grid. This specific mesh allows for the application of FFTs to calculate the near interactions in the MLFMA and reduces the memory cost considerably, since the aggregation and disaggregation matrices of the MLFMA can be reused. Additional improvements to the general MLFMA framework, such as an extention of the FFT interpolation scheme of Sarvas et al. from the scalar to the vectorial case in combination with a more economical representation of the radiation patterns on the lowest level in vector spherical harmonics, are proposed and the choice of the subdomain size is discussed. The hybrid method performs better in terms of speed and memory use on large sparse configurations than both the FFT method and the HF MLFMA separately and it has lower memory requirements on general large problems. This is illustrated on a number of representative numerical test cases.

  8. Radiochromic 3D Detectors

    NASA Astrophysics Data System (ADS)

    Oldham, Mark

    2015-01-01

    Radiochromic materials exhibit a colour change when exposed to ionising radiation. Radiochromic film has been used for clinical dosimetry for many years and increasingly so recently, as films of higher sensitivities have become available. The two principle advantages of radiochromic dosimetry include greater tissue equivalence (radiologically) and the lack of requirement for development of the colour change. In a radiochromic material, the colour change arises direct from ionising interactions affecting dye molecules, without requiring any latent chemical, optical or thermal development, with important implications for increased accuracy and convenience. It is only relatively recently however, that 3D radiochromic dosimetry has become possible. In this article we review recent developments and the current state-of-the-art of 3D radiochromic dosimetry, and the potential for a more comprehensive solution for the verification of complex radiation therapy treatments, and 3D dose measurement in general.

  9. 3-D Seismic Interpretation

    NASA Astrophysics Data System (ADS)

    Moore, Gregory F.

    2009-05-01

    This volume is a brief introduction aimed at those who wish to gain a basic and relatively quick understanding of the interpretation of three-dimensional (3-D) seismic reflection data. The book is well written, clearly illustrated, and easy to follow. Enough elementary mathematics are presented for a basic understanding of seismic methods, but more complex mathematical derivations are avoided. References are listed for readers interested in more advanced explanations. After a brief introduction, the book logically begins with a succinct chapter on modern 3-D seismic data acquisition and processing. Standard 3-D acquisition methods are presented, and an appendix expands on more recent acquisition techniques, such as multiple-azimuth and wide-azimuth acquisition. Although this chapter covers the basics of standard time processing quite well, there is only a single sentence about prestack depth imaging, and anisotropic processing is not mentioned at all, even though both techniques are now becoming standard.

  10. Bootstrapping 3D fermions

    DOE PAGES

    Iliesiu, Luca; Kos, Filip; Poland, David; Pufu, Silviu S.; Simmons-Duffin, David; Yacoby, Ran

    2016-03-17

    We study the conformal bootstrap for a 4-point function of fermions <ψψψψ> in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ × ψ OPE, and also on the central charge CT. We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N. Finally, we also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.

  11. Decoding 3D reach and grasp from hybrid signals in motor and premotor cortices: spikes, multiunit activity, and local field potentials.

    PubMed

    Bansal, Arjun K; Truccolo, Wilson; Vargas-Irwin, Carlos E; Donoghue, John P

    2012-03-01

    Neural activity in motor cortex during reach and grasp movements shows modulations in a broad range of signals from single-neuron spiking activity (SA) to various frequency bands in broadband local field potentials (LFPs). In particular, spatiotemporal patterns in multiband LFPs are thought to reflect dendritic integration of local and interareal synaptic inputs, attentional and preparatory processes, and multiunit activity (MUA) related to movement representation in the local motor area. Nevertheless, the relationship between multiband LFPs and SA, and their relationship to movement parameters and their relative value as brain-computer interface (BCI) control signals, remain poorly understood. Also, although this broad range of signals may provide complementary information channels in primary (MI) and ventral premotor (PMv) areas, areal differences in information have not been systematically examined. Here, for the first time, the amount of information in SA and multiband LFPs was compared for MI and PMv by recording from dual 96-multielectrode arrays while monkeys made naturalistic reach and grasp actions. Information was assessed as decoding accuracy for 3D arm end point and grip aperture kinematics based on SA or LFPs in MI and PMv, or combinations of signal types across areas. In contrast with previous studies with ≤16 simultaneous electrodes, here ensembles of >16 units (on average) carried more information than multiband, multichannel LFPs. Furthermore, reach and grasp information added by various LFP frequency bands was not independent from that in SA ensembles but rather typically less than and primarily contained within the latter. Notably, MI and PMv did not show a particular bias toward reach or grasp for this task or for a broad range of signal types. For BCIs, our results indicate that neuronal ensemble spiking is the preferred signal for decoding, while LFPs and combined signals from PMv and MI can add robustness to BCI control. PMID:22157115

  12. Venus in 3D

    NASA Astrophysics Data System (ADS)

    Plaut, J. J.

    1993-08-01

    Stereographic images of the surface of Venus which enable geologists to reconstruct the details of the planet's evolution are discussed. The 120-meter resolution of these 3D images make it possible to construct digital topographic maps from which precise measurements can be made of the heights, depths, slopes, and volumes of geologic structures.

  13. 3D reservoir visualization

    SciTech Connect

    Van, B.T.; Pajon, J.L.; Joseph, P. )

    1991-11-01

    This paper shows how some simple 3D computer graphics tools can be combined to provide efficient software for visualizing and analyzing data obtained from reservoir simulators and geological simulations. The animation and interactive capabilities of the software quickly provide a deep understanding of the fluid-flow behavior and an accurate idea of the internal architecture of a reservoir.

  14. Syntheses, structures and photocatalytic properties of five new praseodymium-antimony oxochlorides: from discrete clusters to 3D inorganic-organic hybrid racemic compounds.

    PubMed

    Zou, Guo-Dong; Wang, Ze-Ping; Song, Ying; Hu, Bing; Huang, Xiao-Ying

    2014-07-14

    Five novel praseodymium-antimony oxochloride (Pr-Sb-O-Cl) cluster-based compounds, namely (2-MepyH)2[Fe(1,10-phen)3]2[Pr4Sb12O18Cl14.6(OH)2.4(Hsal)]·H2O (1), (2-MepyH)2[Fe(1,10-phen)3]4{[Pr4Sb12O18Cl13.5(OH)0.5](bcpb)2[Pr4Sb12O18Cl13.5(OH)0.5]}·42H2O (2), (3-MepyH)2[Fe(1,10-phen)3]{[Pr4Sb12O18Cl13(H2O)2](bcpb)}·2(3-Mepy)·3H2O (3), [Fe(1,10-phen)3]2{[Pr4Sb12O18Cl10(H2O)2](bcpb)2}·3(3-Mepy)·13H2O (4), and (2-MepyH)6[Fe(1,10-phen)3]10{[Pr4Sb12O18Cl13(OH)2]2[Pr4Sb12O18Cl9][Pr4Sb12O18Cl9(OH)2]2(Hpdc)10(pdc)2}·110H2O (5) (2-Mepy = 2-methylpyridine, 3-Mepy = 3-methylpyridine, 1,10-phen = 1,10-phenanthroline, H2sal = salicylic acid, H3bcpb = 3,5-bis(4-carboxyphenoxy)benzoic acid, H3pdc = 3,5-pyrazoledicarboxylic acid) have been solvothermally synthesized and structurally characterized. Compound 1 is the first zero-dimensional (0D) Pr-Sb-O-Cl cluster decorated by an organic ligand. Compounds 2-4 are constructed from the same H3bcpb ligands but adopt different structures: 2 represents a rare example of a one-dimensional (1D) nanotubular structure based on high-nuclearity clusters; 3 exhibits a two-dimensional (2D) mono-layered structure, in which left-handed and right-handed helical chains are alternately arranged, while 4 features a double-layered structure with an unprecedented (3,3,6)-connected 3-nodal topological net. Compound 5 is a unique three-dimensional (3D) 2-fold interpenetrating racemic compound, simultaneously containing three kinds of Pr-Sb-O-Cl-pdc clusters. UV-light photocatalytic H2 evolution activity was observed for compound 3 with Pt as a co-catalyst and MeOH as a sacrificial electron donor. In addition, the magnetic properties of compounds 1 and 5 are also studied.

  15. Syntheses, structures and photocatalytic properties of five new praseodymium-antimony oxochlorides: from discrete clusters to 3D inorganic-organic hybrid racemic compounds.

    PubMed

    Zou, Guo-Dong; Wang, Ze-Ping; Song, Ying; Hu, Bing; Huang, Xiao-Ying

    2014-07-14

    Five novel praseodymium-antimony oxochloride (Pr-Sb-O-Cl) cluster-based compounds, namely (2-MepyH)2[Fe(1,10-phen)3]2[Pr4Sb12O18Cl14.6(OH)2.4(Hsal)]·H2O (1), (2-MepyH)2[Fe(1,10-phen)3]4{[Pr4Sb12O18Cl13.5(OH)0.5](bcpb)2[Pr4Sb12O18Cl13.5(OH)0.5]}·42H2O (2), (3-MepyH)2[Fe(1,10-phen)3]{[Pr4Sb12O18Cl13(H2O)2](bcpb)}·2(3-Mepy)·3H2O (3), [Fe(1,10-phen)3]2{[Pr4Sb12O18Cl10(H2O)2](bcpb)2}·3(3-Mepy)·13H2O (4), and (2-MepyH)6[Fe(1,10-phen)3]10{[Pr4Sb12O18Cl13(OH)2]2[Pr4Sb12O18Cl9][Pr4Sb12O18Cl9(OH)2]2(Hpdc)10(pdc)2}·110H2O (5) (2-Mepy = 2-methylpyridine, 3-Mepy = 3-methylpyridine, 1,10-phen = 1,10-phenanthroline, H2sal = salicylic acid, H3bcpb = 3,5-bis(4-carboxyphenoxy)benzoic acid, H3pdc = 3,5-pyrazoledicarboxylic acid) have been solvothermally synthesized and structurally characterized. Compound 1 is the first zero-dimensional (0D) Pr-Sb-O-Cl cluster decorated by an organic ligand. Compounds 2-4 are constructed from the same H3bcpb ligands but adopt different structures: 2 represents a rare example of a one-dimensional (1D) nanotubular structure based on high-nuclearity clusters; 3 exhibits a two-dimensional (2D) mono-layered structure, in which left-handed and right-handed helical chains are alternately arranged, while 4 features a double-layered structure with an unprecedented (3,3,6)-connected 3-nodal topological net. Compound 5 is a unique three-dimensional (3D) 2-fold interpenetrating racemic compound, simultaneously containing three kinds of Pr-Sb-O-Cl-pdc clusters. UV-light photocatalytic H2 evolution activity was observed for compound 3 with Pt as a co-catalyst and MeOH as a sacrificial electron donor. In addition, the magnetic properties of compounds 1 and 5 are also studied. PMID:24869770

  16. Segmentation of 3D microPET images of the rat brain via the hybrid gaussian mixture method with kernel density estimation.

    PubMed

    Chen, Tai-Been; Chen, Jyh-Cheng; Lu, Henry Horng-Shing

    2012-01-01

    Segmentation of positron emission tomography (PET) is typically achieved using the K-Means method or other approaches. In preclinical and clinical applications, the K-Means method needs a prior estimation of parameters such as the number of clusters and appropriate initialized values. This work segments microPET images using a hybrid method combining the Gaussian mixture model (GMM) with kernel density estimation. Segmentation is crucial to registration of disordered 2-deoxy-2-fluoro-D-glucose (FDG) accumulation locations with functional diagnosis and to estimate standardized uptake values (SUVs) of region of interests (ROIs) in PET images. Therefore, simulation studies are conducted to apply spherical targets to evaluate segmentation accuracy based on Tanimoto's definition of similarity. The proposed method generates a higher degree of similarity than the K-Means method. The PET images of a rat brain are used to compare the segmented shape and area of the cerebral cortex by the K-Means method and the proposed method by volume rendering. The proposed method provides clearer and more detailed activity structures of an FDG accumulation location in the cerebral cortex than those by the K-Means method. PMID:22948355

  17. High-Pressure Single-Crystal Structures of 3D Lead-Halide Hybrid Perovskites and Pressure Effects on their Electronic and Optical Properties.

    PubMed

    Jaffe, Adam; Lin, Yu; Beavers, Christine M; Voss, Johannes; Mao, Wendy L; Karunadasa, Hemamala I

    2016-04-27

    We report the first high-pressure single-crystal structures of hybrid perovskites. The crystalline semiconductors (MA)PbX3 (MA = CH3NH3 (+), X = Br(-) or I(-)) afford us the rare opportunity of understanding how compression modulates their structures and thereby their optoelectronic properties. Using atomic coordinates obtained from high-pressure single-crystal X-ray diffraction we track the perovskites' precise structural evolution upon compression. These structural changes correlate well with pressure-dependent single-crystal photoluminescence (PL) spectra and high-pressure bandgaps derived from density functional theory. We further observe dramatic piezochromism where the solids become lighter in color and then transition to opaque black with compression. Indeed, electronic conductivity measurements of (MA)PbI3 obtained within a diamond-anvil cell show that the material's resistivity decreases by 3 orders of magnitude between 0 and 51 GPa. The activation energy for conduction at 51 GPa is only 13.2(3) meV, suggesting that the perovskite is approaching a metallic state. Furthermore, the pressure response of mixed-halide perovskites shows new luminescent states that emerge at elevated pressures. We recently reported that the perovskites (MA)Pb(Br x I1-x )3 (0.2 < x < 1) reversibly form light-induced trap states, which pin their PL to a low energy. This may explain the low voltages obtained from solar cells employing these absorbers. Our high-pressure PL data indicate that compression can mitigate this PL redshift and may afford higher steady-state voltages from these absorbers. These studies show that pressure can significantly alter the transport and thermodynamic properties of these technologically important semiconductors. PMID:27163050

  18. High-Pressure Single-Crystal Structures of 3D Lead-Halide Hybrid Perovskites and Pressure Effects on their Electronic and Optical Properties

    PubMed Central

    2016-01-01

    We report the first high-pressure single-crystal structures of hybrid perovskites. The crystalline semiconductors (MA)PbX3 (MA = CH3NH3+, X = Br– or I–) afford us the rare opportunity of understanding how compression modulates their structures and thereby their optoelectronic properties. Using atomic coordinates obtained from high-pressure single-crystal X-ray diffraction we track the perovskites’ precise structural evolution upon compression. These structural changes correlate well with pressure-dependent single-crystal photoluminescence (PL) spectra and high-pressure bandgaps derived from density functional theory. We further observe dramatic piezochromism where the solids become lighter in color and then transition to opaque black with compression. Indeed, electronic conductivity measurements of (MA)PbI3 obtained within a diamond-anvil cell show that the material’s resistivity decreases by 3 orders of magnitude between 0 and 51 GPa. The activation energy for conduction at 51 GPa is only 13.2(3) meV, suggesting that the perovskite is approaching a metallic state. Furthermore, the pressure response of mixed-halide perovskites shows new luminescent states that emerge at elevated pressures. We recently reported that the perovskites (MA)Pb(BrxI1–x)3 (0.2 < x < 1) reversibly form light-induced trap states, which pin their PL to a low energy. This may explain the low voltages obtained from solar cells employing these absorbers. Our high-pressure PL data indicate that compression can mitigate this PL redshift and may afford higher steady-state voltages from these absorbers. These studies show that pressure can significantly alter the transport and thermodynamic properties of these technologically important semiconductors. PMID:27163050

  19. High-Pressure Single-Crystal Structures of 3D Lead-Halide Hybrid Perovskites and Pressure Effects on their Electronic and Optical Properties.

    PubMed

    Jaffe, Adam; Lin, Yu; Beavers, Christine M; Voss, Johannes; Mao, Wendy L; Karunadasa, Hemamala I

    2016-04-27

    We report the first high-pressure single-crystal structures of hybrid perovskites. The crystalline semiconductors (MA)PbX3 (MA = CH3NH3 (+), X = Br(-) or I(-)) afford us the rare opportunity of understanding how compression modulates their structures and thereby their optoelectronic properties. Using atomic coordinates obtained from high-pressure single-crystal X-ray diffraction we track the perovskites' precise structural evolution upon compression. These structural changes correlate well with pressure-dependent single-crystal photoluminescence (PL) spectra and high-pressure bandgaps derived from density functional theory. We further observe dramatic piezochromism where the solids become lighter in color and then transition to opaque black with compression. Indeed, electronic conductivity measurements of (MA)PbI3 obtained within a diamond-anvil cell show that the material's resistivity decreases by 3 orders of magnitude between 0 and 51 GPa. The activation energy for conduction at 51 GPa is only 13.2(3) meV, suggesting that the perovskite is approaching a metallic state. Furthermore, the pressure response of mixed-halide perovskites shows new luminescent states that emerge at elevated pressures. We recently reported that the perovskites (MA)Pb(Br x I1-x )3 (0.2 < x < 1) reversibly form light-induced trap states, which pin their PL to a low energy. This may explain the low voltages obtained from solar cells employing these absorbers. Our high-pressure PL data indicate that compression can mitigate this PL redshift and may afford higher steady-state voltages from these absorbers. These studies show that pressure can significantly alter the transport and thermodynamic properties of these technologically important semiconductors.

  20. 3D rapid mapping

    NASA Astrophysics Data System (ADS)

    Isaksson, Folke; Borg, Johan; Haglund, Leif

    2008-04-01

    In this paper the performance of passive range measurement imaging using stereo technique in real time applications is described. Stereo vision uses multiple images to get depth resolution in a similar way as Synthetic Aperture Radar (SAR) uses multiple measurements to obtain better spatial resolution. This technique has been used in photogrammetry for a long time but it will be shown that it is now possible to do the calculations, with carefully designed image processing algorithms, in e.g. a PC in real time. In order to get high resolution and quantitative data in the stereo estimation a mathematical camera model is used. The parameters to the camera model are settled in a calibration rig or in the case of a moving camera the scene itself can be used for calibration of most of the parameters. After calibration an ordinary TV camera has an angular resolution like a theodolite, but to a much lower price. The paper will present results from high resolution 3D imagery from air to ground. The 3D-results from stereo calculation of image pairs are stitched together into a large database to form a 3D-model of the area covered.

  1. Global magnetosphere-like 3D structure formation in kinetics by hot magnetized plasma flow characterized by shape of the particle distribution function

    NASA Astrophysics Data System (ADS)

    Gubchenko, Vladimir

    The task was to provide an analytical elementary magnetosphere-like model in kinetics for verification of the 3D EM PIC codes created for space/aerospace and HED plasmas applications. Kinetic approach versus cold MHD approach takes into account different behavior in the EM fields of resonant and non resonant particles in the velocity phase space, which appears via shape characteristics of the particle velocity distribution function (PVDF) and via the spatial dispersion effect forming the collisionless dissipation in the EM fields. The external flow is a hot collisionless plasma characterized by the particle velocity distribution function (PVDF) with different shapes: Maxwellian, kappa, etc. The flow is in a “hot regime”: it can be supersonic but its velocity remains less the thermal velocity of the electrons. The “internal” part of the magnetosphere formed by trapped particles is the prescribed 3D stationary magnetization considered as a spherical “quasiparticle” with internal magnetodipole and toroidal moments represented as a broadband EM driver. We obtain after the linearization of Vlasov/Maxwell equations a self-consistent 3D large scale kinetic solution of the classic problem. Namely, we: model the “outer” part of the magnetosphere formed by external hot plasma flow of the flyby particles. Solution of the Vlasov equation expressed via a tensor of dielectric permittivity of nonmagnetized and magnetized flowing plasma. Here, we obtain the direct kinetic dissipative effect of the magnetotail formation and the opposite diamagnetic effect of the magnetosphere “dipolization”. We get MHD wave cone in flow magnetized by external guiding magnetic (GM) field. Magnetosphere in our consideration is a 3D dissipative “wave” package structure of the skinned EM fields formed by the “waves” excited at frequency bands where we obtain negative values and singularities (resonances) of squared EM refractive index of the cold plasma. The hot regime

  2. Ontology analysis of global gene expression differences of human bone marrow stromal cells cultured on 3D scaffolds or 2D films.

    PubMed

    Baker, Bryan A; Pine, P Scott; Chatterjee, Kaushik; Kumar, Girish; Lin, Nancy J; McDaniel, Jennifer H; Salit, Marc L; Simon, Carl G

    2014-08-01

    Differences in gene expression of human bone marrow stromal cells (hBMSCs) during culture in three-dimensional (3D) nanofiber scaffolds or on two-dimensional (2D) films were investigated via pathway analysis of microarray mRNA expression profiles. Previous work has shown that hBMSC culture in nanofiber scaffolds can induce osteogenic differentiation in the absence of osteogenic supplements (OS). Analysis using ontology databases revealed that nanofibers and OS regulated similar pathways and that both were enriched for TGF-β and cell-adhesion/ECM-receptor pathways. The most notable difference between the two was that nanofibers had stronger enrichment for cell-adhesion/ECM-receptor pathways. Comparison of nanofibers scaffolds with flat films yielded stronger differences in gene expression than comparison of nanofibers made from different polymers, suggesting that substrate structure had stronger effects on cell function than substrate polymer composition. These results demonstrate that physical (nanofibers) and biochemical (OS) signals regulate similar ontological pathways, suggesting that these cues use similar molecular mechanisms to control hBMSC differentiation. PMID:24840613

  3. Taming supersymmetric defects in 3d-3d correspondence

    NASA Astrophysics Data System (ADS)

    Gang, Dongmin; Kim, Nakwoo; Romo, Mauricio; Yamazaki, Masahito

    2016-07-01

    We study knots in 3d Chern-Simons theory with complex gauge group {SL}(N,{{C}}), in the context of its relation with 3d { N }=2 theory (the so-called 3d-3d correspondence). The defect has either co-dimension 2 or co-dimension 4 inside the 6d (2,0) theory, which is compactified on a 3-manifold \\hat{M}. We identify such defects in various corners of the 3d-3d correspondence, namely in 3d {SL}(N,{{C}}) CS theory, in 3d { N }=2 theory, in 5d { N }=2 super Yang-Mills theory, and in the M-theory holographic dual. We can make quantitative checks of the 3d-3d correspondence by computing partition functions at each of these theories. This Letter is a companion to a longer paper [1], which contains more details and more results.

  4. 3D Audio System

    NASA Technical Reports Server (NTRS)

    1992-01-01

    Ames Research Center research into virtual reality led to the development of the Convolvotron, a high speed digital audio processing system that delivers three-dimensional sound over headphones. It consists of a two-card set designed for use with a personal computer. The Convolvotron's primary application is presentation of 3D audio signals over headphones. Four independent sound sources are filtered with large time-varying filters that compensate for motion. The perceived location of the sound remains constant. Possible applications are in air traffic control towers or airplane cockpits, hearing and perception research and virtual reality development.

  5. Assessment of Anthropogenic and Climatic Impacts on the Global Carbon Cycle Using a 3-D Model Constrained by Isotopic Carbon Measurements and Remote Sensing of Vegetation

    NASA Technical Reports Server (NTRS)

    Keeling, Charles D.; Piper, S. C.

    1998-01-01

    Our original proposal called for improved modeling of the terrestrial biospheric carbon cycle, specifically using biome-specific process models to account for both the energy and water budgets of plant growth, to facilitate investigations into recent changes in global atmospheric CO2 abundance and regional distribution. The carbon fluxes predicted by these models were to be incorporated into a global model of CO2 transport to establish large-scale regional fluxes of CO2 to and from the terrestrial biosphere subject to constraints imposed by direct measurements of atmospheric CO2 and its 13C/12C isotopic ratio. Our work was coordinated with a NASA project (NASA NAGW-3151) at the University of Montana under the direction of Steven Running, and was partially funded by the Electric Power Research Institute. The primary objective of this project was to develop and test the Biome-BGC model, a global biological process model with a daily time step which simulates the water, energy and carbon budgets of plant growth. The primary product, the unique global gridded daily land temperature, and the precipitation data set which was used to drive the process model is described. The Biome-BGC model was tested by comparison with a simpler biological model driven by satellite-derived (NDVI) Normalized Difference Vegetation Index and (PAR) Photosynthetically Active Radiation data and by comparison with atmospheric CO2 observations. The simple NDVI model is also described. To facilitate the comparison with atmospheric CO2 observations, a three-dimensional atmospheric transport model was used to produce predictions of atmospheric CO2 variations given CO2 fluxes owing to (NPP) Net Primary Productivity and heterotrophic respiration that were produced by the Biome-BGC model and by the NDVI model. The transport model that we used in this project, and errors associated with transport simulations, were characterized by a comparison of 12 transport models.

  6. Tidal energy conversion in a global hot spot: On the 3-D dynamics of baroclinic tides at the Celtic Sea shelf break

    NASA Astrophysics Data System (ADS)

    Vlasenko, Vasiliy; Stashchuk, Nataliya; Inall, Mark E.; Hopkins, Joanne E.

    2014-06-01

    Globally, the Celtic Sea shelf break is ranked highest as an energetic "hot spot" of tidal energy conversion, therefore making it the most significant contributor to global internal tidal energy flux. In this paper, the three-dimensional dynamics of baroclinic tides in the shelf-slope area of the Celtic Sea was investigated numerically and using observational data collected on the 376th cruise of the RV "RRS Discovery" in June 2012. The time series recorded at a shelf break mooring showed that semidiurnal internal waves were accompanied by packets of internal solitary waves with maximum amplitudes up to 105 m, the largest internal waves ever recorded in the Celtic Sea, and ranking among the largest observed in the global ocean. The observed baroclinic wavefields were replicated numerically using the Massachusetts Institute of Technology general circulation model. A fine-resolution grid with 115 m horizontal and 10 m vertical steps allowed the identification of two classes of short-scale internal waves. The first classification was generated over headlands and resembles spiral-type internal waves that are typical for isolated underwater banks. The second classification, generated within an area of several canyons, revealed properties of quasi-planar internal wave packets. The observed in situ intensification of tidal bottom currents at the shelf break mooring is explained in terms of a tidal beam that was formed over supercritical bottom topography at the mooring location.

  7. Dipolarization fronts as earthward propagating flux ropes: A three-dimensional global hybrid simulation

    NASA Astrophysics Data System (ADS)

    Lu, S.; Lu, Q.; Lin, Y.; Wang, X.; Ge, Y.; Wang, R.; Zhou, M.; Fu, H.; Huang, C.; Wu, M.; Wang, S.

    2015-12-01

    Dipolarization fronts (DFs) as earthward propagating flux ropes (FRs) in the Earth's magnetotail are presented and investigated with a three-dimensional (3-D) global hybrid simulation for the first time. In the simulation, several small-scale earthward propagating FRs are found to be formed by multiple X-line reconnection in the near-tail. During their earthward propagation, the magnetic field Bz of the FRs becomes highly asymmetric due to the imbalance of the reconnection rates between the multiple X-lines. At the later stage, when the FRs approach the near-Earth dipole-like region, the anti-reconnection between the southward/negative Bz of the FRs and the northward geomagnetic field leads to the erosion of the southward magnetic flux of the FRs, which further aggravates the Bz asymmetry. Eventually, the FRs merge into the near-Earth region through the anti-reconnection. These earthward propagating FRs can fully reproduce the observational features of the DFs, e.g., a sharp enhancement of Bz preceded by a smaller amplitude Bz dip, an earthward flow enhancement, the presence of the electric field components in the normal and dawn-dusk directions, and ion energization. Our results show that the earthward propagating FRs can be used to explain the DFs observed in the magnetotail. The thickness of the DFs is on the order of several ion inertial lengths, and the electric field normal to the front is found to be dominated by the Hall physics. During the earthward propagation from the near-tail to the near-Earth region, the speed of the FR/DFs increases from ~150km/s to ~1000km/s. The FR/DFs can be tilted in the GSM xy plane with respect to the y (dawn-dusk) axis and only extend several RE in this direction. Moreover, the structure and evolution of the FRs/DFs are non-uniform in the dawn-dusk direction, which indicates that the DFs are essentially 3-D.

  8. Positional Awareness Map 3D (PAM3D)

    NASA Technical Reports Server (NTRS)

    Hoffman, Monica; Allen, Earl L.; Yount, John W.; Norcross, April Louise

    2012-01-01

    The Western Aeronautical Test Range of the National Aeronautics and Space Administration s Dryden Flight Research Center needed to address the aging software and hardware of its current situational awareness display application, the Global Real-Time Interactive Map (GRIM). GRIM was initially developed in the late 1980s and executes on older PC architectures using a Linux operating system that is no longer supported. Additionally, the software is difficult to maintain due to its complexity and loss of developer knowledge. It was decided that a replacement application must be developed or acquired in the near future. The replacement must provide the functionality of the original system, the ability to monitor test flight vehicles in real-time, and add improvements such as high resolution imagery and true 3-dimensional capability. This paper will discuss the process of determining the best approach to replace GRIM, and the functionality and capabilities of the first release of the Positional Awareness Map 3D.

  9. Global 3-d modeling of atmospheric ozone in the free troposphere and the stratosphere with emphasis on midlatitude regions. Final report, July 1, 1994--June 30, 1997

    SciTech Connect

    Brasseur, G.; Erickson, D.; Tie, X.; Walter, S.

    1997-12-01

    The objective of this research is to use global chemical-transport models to study the chemical and dynamical processes that affect midlatitude stratospheric ozone and to quantify the budget of tropospheric ozone. Four models will be improved and used: (1) a new version of the two-dimensional chemical-radiative-dynamical model with microphysical process of sulfate aerosols and polar stratospheric clouds (PSCs), and heterogeneous conversions on the surfaces of sulfate aerosols and PSCs; (2) the stratospheric version of three-dimensional off-line chemical-transport model (STARS) with a relatively high horizontal resolution (2.8 degree in latitudes) with a microphysical formation of PSCs; (3) the tropospheric version of three-dimensional off-line chemical-transport model (MOZART) with details in the surface emissions and hydrocarbon reactions to estimate the tropospheric ozone budget and perturbations; (4) the intermediate model of the global and annual evolution of species (IMAGES) with a detailed chemical reactions but relatively lower resolutions. Model results will be compared with available data.

  10. Global 3-D modeling of atmospheric ozone in the free troposphere and the stratosphere with emphasis on midlatitude regions. Final report

    SciTech Connect

    Brasseur, G.; Tie, X.; Walters, S.

    1999-03-01

    The authors have used several global chemical/transport models (1) to study the contribution of various physical, chemical, and dynamical processes to the budget of mid-latitude ozone in the stratosphere and troposphere; (2) to analyze the potential mechanisms which are responsible for the observed ozone perturbations at mid-latitudes of the lower stratosphere and in the upper troposphere; (3) to calculate potential changes in atmospheric ozone response to anthropogenic changes (e.g., emission of industrially manufactured CFCs, CO, and NO{sub x}) and to natural perturbations (e.g., volcanic eruptions and biomass burning); and (4) to estimate the impact of these changes on the radiative forcing to the climate system and on the level of UV-B radiation at the surface.

  11. 3D integrated hybrid silicon laser.

    PubMed

    Song, Bowen; Stagarescu, Cristian; Ristic, Sasa; Behfar, Alex; Klamkin, Jonathan

    2016-05-16

    Lasers were realized on silicon by flip-chip bonding of indium phosphide (InP) devices containing total internal reflection turning mirrors for surface emission. Light is coupled to the silicon waveguides through surface grating couplers. With this technique, InP lasers were integrated on silicon. Laser cavities were also formed by coupling InP reflective semiconductor optical amplifiers to microring resonator filters and distributed Bragg reflector mirrors. Single-mode continuous wave lasing was demonstrated with a side mode suppression ratio of 30 dB. Up to 2 mW of optical power was coupled to the silicon waveguide. Thermal simulations were also performed to evaluate the low thermal impedance afforded by this architecture and potential for high wall-plug efficiency. PMID:27409867

  12. Modeling Cellular Processes in 3-D

    PubMed Central

    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

  13. Prominent rocks - 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Many prominent rocks near the Sagan Memorial Station are featured in this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. Wedge is at lower left; Shark, Half-Dome, and Pumpkin are at center. Flat Top, about four inches high, is at lower right. The horizon in the distance is one to two kilometers away.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  14. 'Diamond' in 3-D

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This 3-D, microscopic imager mosaic of a target area on a rock called 'Diamond Jenness' was taken after NASA's Mars Exploration Rover Opportunity ground into the surface with its rock abrasion tool for a second time.

    Opportunity has bored nearly a dozen holes into the inner walls of 'Endurance Crater.' On sols 177 and 178 (July 23 and July 24, 2004), the rover worked double-duty on Diamond Jenness. Surface debris and the bumpy shape of the rock resulted in a shallow and irregular hole, only about 2 millimeters (0.08 inch) deep. The final depth was not enough to remove all the bumps and leave a neat hole with a smooth floor. This extremely shallow depression was then examined by the rover's alpha particle X-ray spectrometer.

    On Sol 178, Opportunity's 'robotic rodent' dined on Diamond Jenness once again, grinding almost an additional 5 millimeters (about 0.2 inch). The rover then applied its Moessbauer spectrometer to the deepened hole. This double dose of Diamond Jenness enabled the science team to examine the rock at varying layers. Results from those grindings are currently being analyzed.

    The image mosaic is about 6 centimeters (2.4 inches) across.

  15. Martian terrain - 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This area of terrain near the Sagan Memorial Station was taken on Sol 3 by the Imager for Mars Pathfinder (IMP). 3D glasses are necessary to identify surface detail.

    The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  16. 3D ultrafast laser scanner

    NASA Astrophysics Data System (ADS)

    Mahjoubfar, A.; Goda, K.; Wang, C.; Fard, A.; Adam, J.; Gossett, D. R.; Ayazi, A.; Sollier, E.; Malik, O.; Chen, E.; Liu, Y.; Brown, R.; Sarkhosh, N.; Di Carlo, D.; Jalali, B.

    2013-03-01

    Laser scanners are essential for scientific research, manufacturing, defense, and medical practice. Unfortunately, often times the speed of conventional laser scanners (e.g., galvanometric mirrors and acousto-optic deflectors) falls short for many applications, resulting in motion blur and failure to capture fast transient information. Here, we present a novel type of laser scanner that offers roughly three orders of magnitude higher scan rates than conventional methods. Our laser scanner, which we refer to as the hybrid dispersion laser scanner, performs inertia-free laser scanning by dispersing a train of broadband pulses both temporally and spatially. More specifically, each broadband pulse is temporally processed by time stretch dispersive Fourier transform and further dispersed into space by one or more diffractive elements such as prisms and gratings. As a proof-of-principle demonstration, we perform 1D line scans at a record high scan rate of 91 MHz and 2D raster scans and 3D volumetric scans at an unprecedented scan rate of 105 kHz. The method holds promise for a broad range of scientific, industrial, and biomedical applications. To show the utility of our method, we demonstrate imaging, nanometer-resolved surface vibrometry, and high-precision flow cytometry with real-time throughput that conventional laser scanners cannot offer due to their low scan rates.

  17. Thermomechanical properties of 3d transition metals

    SciTech Connect

    Karaoglu, B.; Rahman, S.M.M. . Dept. of Physics)

    1994-05-15

    The authors have investigated the density variation of the Einstein temperatures and elastic constants of the 3d transition metals. In this respect they have employed the transition metal (TM) pair potentials involving the sp contribution with an appropriate exchange and correlation function, the d-band broadening contribution and the d-band hybridization term. These calculations are aimed at testing the TM pair potentials in generating the quasilocal and local thermomechanical properties.

  18. One- and many-electron self-interaction error in local and global hybrid functionals

    NASA Astrophysics Data System (ADS)

    Schmidt, Tobias; Kümmel, Stephan

    2016-04-01

    Electronic self-interaction poses a fundamental challenge in density-functional theory. It greatly limits, e.g., the physical interpretation of eigenvalues as electron removal energies. We here investigate whether local hybrid functionals that are designed to be free from one-electron self-interaction lead to occupied Kohn-Sham eigenvalues and orbitals that approximate photoemission observables well. We compare the local hybrid results to the ones from global hybrid functionals that only partially counteract the self-interaction, and to the results that are obtained with a Perdew-Zunger-type self-interaction correction. Furthermore, we check whether being nominally free from one-electron self-interaction translates into a reduced many-electron self-interaction error. Our findings show that this is not the case for the local hybrid functionals that we studied: In practice they are similar to global hybrids in many respects, despite being formally superior. This finding indicates that there is a conceptual difference between the Perdew-Zunger way and the local hybrid way of translating the one-electron condition to a many-electron system. We also point out and solve some difficulties that occur when using local hybrid functionals in combination with pseudopotentials.

  19. M3D project for simulation studies of plasmas

    SciTech Connect

    Park, W.; Belova, E.V.; Fu, G.Y.; Strauss, H.R.; Sugiyama, L.E.

    1998-12-31

    The M3D (Multi-level 3D) project carries out simulation studies of plasmas of various regimes using multi-levels of physics, geometry, and mesh schemes in one code package. This paper and papers by Strauss, Sugiyama, and Belova in this workshop describe the project, and present examples of current applications. The currently available physics models of the M3D project are MHD, two-fluids, gyrokinetic hot particle/MHD hybrid, and gyrokinetic particle ion/two-fluid hybrid models. The code can be run with both structured and unstructured meshes.

  20. 3D Elevation Program—Virtual USA in 3D

    USGS Publications Warehouse

    Lukas, Vicki; Stoker, J.M.

    2016-01-01

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.  

  1. 3D Elevation Program—Virtual USA in 3D

    USGS Publications Warehouse

    Lukas, Vicki; Stoker, J.M.

    2016-04-14

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.  

  2. Calculating Path-Dependent Travel Time Prediction Variance and Covariance for the SALSA3D Global Tomographic P-Velocity Model with a Distributed Parallel Multi-Core Computer

    NASA Astrophysics Data System (ADS)

    Hipp, J. R.; Encarnacao, A.; Ballard, S.; Young, C. J.; Phillips, W. S.; Begnaud, M. L.

    2011-12-01

    Recently our combined SNL-LANL research team has succeeded in developing a global, seamless 3D tomographic P-velocity model (SALSA3D) that provides superior first P travel time predictions at both regional and teleseismic distances. However, given the variable data quality and uneven data sampling associated with this type of model, it is essential that there be a means to calculate high-quality estimates of the path-dependent variance and covariance associated with the predicted travel times of ray paths through the model. In this paper, we show a methodology for accomplishing this by exploiting the full model covariance matrix. Our model has on the order of 1/2 million nodes, so the challenge in calculating the covariance matrix is formidable: 0.9 TB storage for 1/2 of a symmetric matrix, necessitating an Out-Of-Core (OOC) blocked matrix solution technique. With our approach the tomography matrix (G which includes Tikhonov regularization terms) is multiplied by its transpose (GTG) and written in a blocked sub-matrix fashion. We employ a distributed parallel solution paradigm that solves for (GTG)-1 by assigning blocks to individual processing nodes for matrix decomposition update and scaling operations. We first find the Cholesky decomposition of GTG which is subsequently inverted. Next, we employ OOC matrix multiply methods to calculate the model covariance matrix from (GTG)-1 and an assumed data covariance matrix. Given the model covariance matrix we solve for the travel-time covariance associated with arbitrary ray-paths by integrating the model covariance along both ray paths. Setting the paths equal gives variance for that path. 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 National Nuclear Security Administration under contract DE-AC04-94AL85000.

  3. 3D genome tuner: compare multiple circular genomes in a 3D context.

    PubMed

    Wang, Qi; Liang, Qun; Zhang, Xiuqing

    2009-09-01

    Circular genomes, being the largest proportion of sequenced genomes, play an important role in genome analysis. However, traditional 2D circular map only provides an overview and annotations of genome but does not offer feature-based comparison. For remedying these shortcomings, we developed 3D Genome Tuner, a hybrid of circular map and comparative map tools. Its capability of viewing comparisons between multiple circular maps in a 3D space offers great benefits to the study of comparative genomics. The program is freely available (under an LGPL licence) at http://sourceforge.net/projects/dgenometuner.

  4. Market study: 3-D eyetracker

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A market study of a proposed version of a 3-D eyetracker for initial use at NASA's Ames Research Center was made. The commercialization potential of a simplified, less expensive 3-D eyetracker was ascertained. Primary focus on present and potential users of eyetrackers, as well as present and potential manufacturers has provided an effective means of analyzing the prospects for commercialization.

  5. 3D World Building System

    ScienceCinema

    None

    2016-07-12

    This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.

  6. 3D World Building System

    SciTech Connect

    2013-10-30

    This video provides an overview of the Sandia National Laboratories developed 3-D World Model Building capability that provides users with an immersive, texture rich 3-D model of their environment in minutes using a laptop and color and depth camera.

  7. [3-D ultrasound in gastroenterology].

    PubMed

    Zoller, W G; Liess, H

    1994-06-01

    Three-dimensional (3D) sonography represents a development of noninvasive diagnostic imaging by real-time two-dimensional (2D) sonography. The use of transparent rotating scans, comparable to a block of glass, generates a 3D effect. The objective of the present study was to optimate 3D presentation of abdominal findings. Additional investigations were made with a new volumetric program to determine the volume of selected findings of the liver. The results were compared with the estimated volumes of 2D sonography and 2D computer tomography (CT). For the processing of 3D images, typical parameter constellations were found for the different findings, which facilitated processing of 3D images. In more than 75% of the cases examined we found an optimal 3D presentation of sonographic findings with respect to the evaluation criteria developed by us for the 3D imaging of processed data. Great differences were found for the estimated volumes of the findings of the liver concerning the three different techniques applied. 3D ultrasound represents a valuable method to judge morphological appearance in abdominal findings. The possibility of volumetric measurements enlarges its potential diagnostic significance. Further clinical investigations are necessary to find out if definite differentiation between benign and malign findings is possible.

  8. Euro3D Science Conference

    NASA Astrophysics Data System (ADS)

    Walsh, J. R.

    2004-02-01

    The Euro3D RTN is an EU funded Research Training Network to foster the exploitation of 3D spectroscopy in Europe. 3D spectroscopy is a general term for spectroscopy of an area of the sky and derives its name from its two spatial + one spectral dimensions. There are an increasing number of instruments which use integral field devices to achieve spectroscopy of an area of the sky, either using lens arrays, optical fibres or image slicers, to pack spectra of multiple pixels on the sky (``spaxels'') onto a 2D detector. On account of the large volume of data and the special methods required to reduce and analyse 3D data, there are only a few centres of expertise and these are mostly involved with instrument developments. There is a perceived lack of expertise in 3D spectroscopy spread though the astronomical community and its use in the armoury of the observational astronomer is viewed as being highly specialised. For precisely this reason the Euro3D RTN was proposed to train young researchers in this area and develop user tools to widen the experience with this particular type of data in Europe. The Euro3D RTN is coordinated by Martin M. Roth (Astrophysikalisches Institut Potsdam) and has been running since July 2002. The first Euro3D science conference was held in Cambridge, UK from 22 to 23 May 2003. The main emphasis of the conference was, in keeping with the RTN, to expose the work of the young post-docs who are funded by the RTN. In addition the team members from the eleven European institutes involved in Euro3D also presented instrumental and observational developments. The conference was organized by Andy Bunker and held at the Institute of Astronomy. There were over thirty participants and 26 talks covered the whole range of application of 3D techniques. The science ranged from Galactic planetary nebulae and globular clusters to kinematics of nearby galaxies out to objects at high redshift. Several talks were devoted to reporting recent observations with newly

  9. 3D printing in dentistry.

    PubMed

    Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A

    2015-12-01

    3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery. PMID:26657435

  10. PLOT3D user's manual

    NASA Technical Reports Server (NTRS)

    Walatka, Pamela P.; Buning, Pieter G.; Pierce, Larry; Elson, Patricia A.

    1990-01-01

    PLOT3D is a computer graphics program designed to visualize the grids and solutions of computational fluid dynamics. Seventy-four functions are available. Versions are available for many systems. PLOT3D can handle multiple grids with a million or more grid points, and can produce varieties of model renderings, such as wireframe or flat shaded. Output from PLOT3D can be used in animation programs. The first part of this manual is a tutorial that takes the reader, keystroke by keystroke, through a PLOT3D session. The second part of the manual contains reference chapters, including the helpfile, data file formats, advice on changing PLOT3D, and sample command files.

  11. 3D printing in dentistry.

    PubMed

    Dawood, A; Marti Marti, B; Sauret-Jackson, V; Darwood, A

    2015-12-01

    3D printing has been hailed as a disruptive technology which will change manufacturing. Used in aerospace, defence, art and design, 3D printing is becoming a subject of great interest in surgery. The technology has a particular resonance with dentistry, and with advances in 3D imaging and modelling technologies such as cone beam computed tomography and intraoral scanning, and with the relatively long history of the use of CAD CAM technologies in dentistry, it will become of increasing importance. Uses of 3D printing include the production of drill guides for dental implants, the production of physical models for prosthodontics, orthodontics and surgery, the manufacture of dental, craniomaxillofacial and orthopaedic implants, and the fabrication of copings and frameworks for implant and dental restorations. This paper reviews the types of 3D printing technologies available and their various applications in dentistry and in maxillofacial surgery.

  12. 3D multispecies collisional model of Ganymede's atmosphere

    NASA Astrophysics Data System (ADS)

    Leblanc, Francois; Leclercq, Ludivine; Oza, Apurva; Schmidt, Carl; Modolo, Ronan; Chaufray, Jean-Yves; Johnson, Robert E.

    2016-10-01

    Ganymede's atmosphere is produced by the interaction of the Sun and of the Jovian magnetosphere with its surface. It is a reflection of Ganymede's surface properties, but also of the complex interaction between the Ganymede and Jupiter magnetospheres. The Exospheric Global Model (EGM) has been developed in order to be able to integrate surface and magnetosphere processes with those in Ganymede's atmosphere. It is a 3D parallelized multi-species collisional model, coupled with LatHys, a hybrid multi-grid 3D multi-species model of Ganymede's magnetosphere (Leclercq et al., Geophys. Res. Let., Submitted, 2016). EGM's description of the species-dependent spatial distribution of Ganymede's atmosphere, its temporal variability during rotation around Jupiter, its connection to the surface, the role of collisions, and respective roles of sublimation and sputtering in producing Ganymede's exosphere, illustrates how modeling combined with in situ and remote sensing of Ganymede's atmosphere can contribute to our understanding of this unique surface-atmosphere-magnetosphere integrated system.

  13. Global Hybrid HRSC+OMEGA Image Mosaics of Mars

    NASA Astrophysics Data System (ADS)

    McGuire, P. C.; Walter, S. H. G.; van Gasselt, S.; Dunke, A.; Dunker, T.; Gross, C.; Michael, G.; Wendt, L.; Audouard, J.; Ody, A.; Poulet, F.

    2014-04-01

    The High Resolution Stereo Camera (HRSC) on the Mars Express (MEx) orbiter has acquired 3640 images (with 'preliminary level 4' processing as described in [1]) of the Martian surface since arriving in orbit in 2003, covering over 90% of the planet [2]. At resolutions that can reach 10 meters/pixel, these MEx/HRSC images [3-4] are constructed in a pushbroom manner from 9 different CCD line sensors, including a panchromatic nadir-looking (Pan) channel, 4 color channels (R, G, B, IR), and 4 other panchromatic channels for stereo imaging or photometric imaging. In [5], we discussed our approach towards automatically mosaicking hundreds of the MEx/HRSC Pan or RGB images together. Herein, we present our latest results using this approach (Fig. 1; PDF is zoomable). Currently, our best results consist of adding a high-pass-filtered version of the HRSC mosaic to a low-pass-filtered version of the MEx/OMEGA [6] global mosaic.

  14. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITHOUT TURB3D)

    NASA Technical Reports Server (NTRS)

    Buning, P.

    1994-01-01

    PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into

  15. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITH TURB3D)

    NASA Technical Reports Server (NTRS)

    Buning, P.

    1994-01-01

    PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into

  16. Hybrid ensemble 4DVar assimilation of stratospheric ozone using a global shallow water model

    NASA Astrophysics Data System (ADS)

    Allen, Douglas R.; Hoppel, Karl W.; Kuhl, David D.

    2016-07-01

    Wind extraction from stratospheric ozone (O3) assimilation is examined using a hybrid ensemble 4-D variational assimilation (4DVar) shallow water model (SWM) system coupled to the tracer advection equation. Stratospheric radiance observations are simulated using global observations of the SWM fluid height (Z), while O3 observations represent sampling by a typical polar-orbiting satellite. Four ensemble sizes were examined (25, 50, 100, and 1518 members), with the largest ensemble equal to the number of dynamical state variables. The optimal length scale for ensemble localization was found by tuning an ensemble Kalman filter (EnKF). This scale was then used for localizing the ensemble covariances that were blended with conventional covariances in the hybrid 4DVar experiments. Both optimal length scale and optimal blending coefficient increase with ensemble size, with optimal blending coefficients varying from 0.2-0.5 for small ensembles to 0.5-1.0 for large ensembles. The hybrid system outperforms conventional 4DVar for all ensemble sizes, while for large ensembles the hybrid produces similar results to the offline EnKF. Assimilating O3 in addition to Z benefits the winds in the hybrid system, with the fractional improvement in global vector wind increasing from ˜ 35 % with 25 and 50 members to ˜ 50 % with 1518 members. For the smallest ensembles (25 and 50 members), the hybrid 4DVar assimilation improves the zonal wind analysis over conventional 4DVar in the Northern Hemisphere (winter-like) region and also at the Equator, where Z observations alone have difficulty constraining winds due to lack of geostrophy. For larger ensembles (100 and 1518 members), the hybrid system results in both zonal and meridional wind error reductions, relative to 4DVar, across the globe.

  17. Energization of Oxygen Ions at Mars: Comparison of a Global Hybrid Model to In Situ Observations

    NASA Astrophysics Data System (ADS)

    Jarvinen, R.; Brain, D. A.; Fedorov, A.; Holmstrom, M.; Modolo, R.

    2015-12-01

    We study the energization of planetary oxygen ions escaping from the atmosphere of Mars in a global hybrid model for the Mars-solar wind interaction. In the hybrid approach ions are modelled as particles moving under the Lorentz force and electrons are a charge-neutralizing fluid. Thus, electric and magnetic field are self-consistently coupled with ion dynamics. We identify ion energization regions in the induced magnetosphere of Mars in the model. Further, we study electric and magnetic fields associated with the ion acceleration processes. Finally, we compare our simulation results to in situ particle and magnetic field observations on the MAVEN and Mars Express missions.

  18. Unassisted 3D camera calibration

    NASA Astrophysics Data System (ADS)

    Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.

    2012-03-01

    With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.

  19. 3-D Maps and Compasses in the Brain.

    PubMed

    Finkelstein, Arseny; Las, Liora; Ulanovsky, Nachum

    2016-07-01

    The world has a complex, three-dimensional (3-D) spatial structure, but until recently the neural representation of space was studied primarily in planar horizontal environments. Here we review the emerging literature on allocentric spatial representations in 3-D and discuss the relations between 3-D spatial perception and the underlying neural codes. We suggest that the statistics of movements through space determine the topology and the dimensionality of the neural representation, across species and different behavioral modes. We argue that hippocampal place-cell maps are metric in all three dimensions, and might be composed of 2-D and 3-D fragments that are stitched together into a global 3-D metric representation via the 3-D head-direction cells. Finally, we propose that the hippocampal formation might implement a neural analogue of a Kalman filter, a standard engineering algorithm used for 3-D navigation. PMID:27442069

  20. Spatially resolved 3D noise

    NASA Astrophysics Data System (ADS)

    Haefner, David P.; Preece, Bradley L.; Doe, Joshua M.; Burks, Stephen D.

    2016-05-01

    When evaluated with a spatially uniform irradiance, an imaging sensor exhibits both spatial and temporal variations, which can be described as a three-dimensional (3D) random process considered as noise. In the 1990s, NVESD engineers developed an approximation to the 3D power spectral density (PSD) for noise in imaging systems known as 3D noise. In this correspondence, we describe how the confidence intervals for the 3D noise measurement allows for determination of the sampling necessary to reach a desired precision. We then apply that knowledge to create a smaller cube that can be evaluated spatially across the 2D image giving the noise as a function of position. The method presented here allows for both defective pixel identification and implements the finite sampling correction matrix. In support of the reproducible research effort, the Matlab functions associated with this work can be found on the Mathworks file exchange [1].

  1. Autofocus for 3D imaging

    NASA Astrophysics Data System (ADS)

    Lee-Elkin, Forest

    2008-04-01

    Three dimensional (3D) autofocus remains a significant challenge for the development of practical 3D multipass radar imaging. The current 2D radar autofocus methods are not readily extendable across sensor passes. We propose a general framework that allows a class of data adaptive solutions for 3D auto-focus across passes with minimal constraints on the scene contents. The key enabling assumption is that portions of the scene are sparse in elevation which reduces the number of free variables and results in a system that is simultaneously solved for scatterer heights and autofocus parameters. The proposed method extends 2-pass interferometric synthetic aperture radar (IFSAR) methods to an arbitrary number of passes allowing the consideration of scattering from multiple height locations. A specific case from the proposed autofocus framework is solved and demonstrates autofocus and coherent multipass 3D estimation across the 8 passes of the "Gotcha Volumetric SAR Data Set" X-Band radar data.

  2. Accepting the T3D

    SciTech Connect

    Rich, D.O.; Pope, S.C.; DeLapp, J.G.

    1994-10-01

    In April, a 128 PE Cray T3D was installed at Los Alamos National Laboratory`s Advanced Computing Laboratory as part of the DOE`s High-Performance Parallel Processor Program (H4P). In conjunction with CRI, the authors implemented a 30 day acceptance test. The test was constructed in part to help them understand the strengths and weaknesses of the T3D. In this paper, they briefly describe the H4P and its goals. They discuss the design and implementation of the T3D acceptance test and detail issues that arose during the test. They conclude with a set of system requirements that must be addressed as the T3D system evolves.

  3. Combinatorial 3D Mechanical Metamaterials

    NASA Astrophysics Data System (ADS)

    Coulais, Corentin; Teomy, Eial; de Reus, Koen; Shokef, Yair; van Hecke, Martin

    2015-03-01

    We present a class of elastic structures which exhibit 3D-folding motion. Our structures consist of cubic lattices of anisotropic unit cells that can be tiled in a complex combinatorial fashion. We design and 3d-print this complex ordered mechanism, in which we combine elastic hinges and defects to tailor the mechanics of the material. Finally, we use this large design space to encode smart functionalities such as surface patterning and multistability.

  4. Efficient Semi-numerical Implementation of Global and Local Hybrid Functionals for Time-Dependent Density Functional Theory.

    PubMed

    Maier, Toni M; Bahmann, Hilke; Kaupp, Martin

    2015-09-01

    Local hybrid functionals with position-dependent exact-exchange admixture offer increased flexibility compared to global hybrids. For sufficiently advanced functionals of this type, this is expected to hold also for a wide range of electronic excitations within time-dependent density functional theory (TDDFT). Following a recent semi-numerical implementation of local hybrid functionals for ground-state self-consistent-field calculations (Bahmann, H.; Kaupp, M. J. Chem. Theory Comput. 2015, 11, 1540-1548), the first linear-response TDDFT implementation of local hybrids is reported, using a semi-numerical integration technique. The timings and accuracy of the semi-numerical implementation are evaluated by comparison with analytical schemes for time-dependent Hartree-Fock (TDHF) and for the TPSSh global hybrid. In combination with the RI approximation to the Coulomb part of the kernel, the semi-numerical implementation is faster than the existing analytical TDDFT/TDHF implementation of global hybrid functionals in the TURBOMOLE code, even for small systems and moderate basis sets. Moreover, timings for global and local hybrids are practically equal for the semi-numerical scheme. The way to TDDFT calculations with local hybrid functionals for large systems is thus now open, and more sophisticated parametrizations of local hybrids may be evaluated.

  5. A 3D Global Climate Model of the Pluto atmosphere coupled to a volatile transport model to interpret New Horizons observations, including the N2, CH4 and CO cycles and the formation of organic hazes

    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

  6. Verification of electromagnetic fluid-kinetic hybrid electron model in global gyrokinetic particle simulation

    NASA Astrophysics Data System (ADS)

    Holod, I.; Lin, Z.

    2013-03-01

    The fluid-kinetic hybrid electron model is verified in global gyrokinetic particle simulation of linear electromagnetic drift-Alfvénic instabilities in tokamak. In particular, we have recovered the β-stabilization of the ion temperature gradient mode, transition to collisionless trapped electron mode, and the onset of kinetic ballooning mode as βe (ratio of electron kinetic pressure to magnetic pressure) increases.

  7. LASTRAC.3d: Transition Prediction in 3D Boundary Layers

    NASA Technical Reports Server (NTRS)

    Chang, Chau-Lyan

    2004-01-01

    Langley Stability and Transition Analysis Code (LASTRAC) is a general-purpose, physics-based transition prediction code released by NASA for laminar flow control studies and transition research. This paper describes the LASTRAC extension to general three-dimensional (3D) boundary layers such as finite swept wings, cones, or bodies at an angle of attack. The stability problem is formulated by using a body-fitted nonorthogonal curvilinear coordinate system constructed on the body surface. The nonorthogonal coordinate system offers a variety of marching paths and spanwise waveforms. In the extreme case of an infinite swept wing boundary layer, marching with a nonorthogonal coordinate produces identical solutions to those obtained with an orthogonal coordinate system using the earlier release of LASTRAC. Several methods to formulate the 3D parabolized stability equations (PSE) are discussed. A surface-marching procedure akin to that for 3D boundary layer equations may be used to solve the 3D parabolized disturbance equations. On the other hand, the local line-marching PSE method, formulated as an easy extension from its 2D counterpart and capable of handling the spanwise mean flow and disturbance variation, offers an alternative. A linear stability theory or parabolized stability equations based N-factor analysis carried out along the streamline direction with a fixed wavelength and downstream-varying spanwise direction constitutes an efficient engineering approach to study instability wave evolution in a 3D boundary layer. The surface-marching PSE method enables a consistent treatment of the disturbance evolution along both streamwise and spanwise directions but requires more stringent initial conditions. Both PSE methods and the traditional LST approach are implemented in the LASTRAC.3d code. Several test cases for tapered or finite swept wings and cones at an angle of attack are discussed.

  8. Global hybrids from the semiclassical atom theory satisfying the local density linear response.

    PubMed

    Fabiano, Eduardo; Constantin, Lucian A; Cortona, Pietro; Della Sala, Fabio

    2015-01-13

    We propose global hybrid approximations of the exchange-correlation (XC) energy functional which reproduce well the modified fourth-order gradient expansion of the exchange energy in the semiclassical limit of many-electron neutral atoms and recover the full local density approximation (LDA) linear response. These XC functionals represent the hybrid versions of the APBE functional [Phys. Rev. Lett. 2011, 106, 186406] yet employing an additional correlation functional which uses the localization concept of the correlation energy density to improve the compatibility with the Hartree-Fock exchange as well as the coupling-constant-resolved XC potential energy. Broad energetic and structural testing, including thermochemistry and geometry, transition metal complexes, noncovalent interactions, gold clusters and small gold-molecule interfaces, as well as an analysis of the hybrid parameters, show that our construction is quite robust. In particular, our testing shows that the resulting hybrid, including 20% of Hartree-Fock exchange and named hAPBE, performs remarkably well for a broad palette of systems and properties, being generally better than popular hybrids (PBE0 and B3LYP). Semiempirical dispersion corrections are also provided. PMID:26574210

  9. A 2D driven 3D vessel segmentation algorithm for 3D digital subtraction angiography data

    NASA Astrophysics Data System (ADS)

    Spiegel, M.; Redel, T.; Struffert, T.; Hornegger, J.; Doerfler, A.

    2011-10-01

    Cerebrovascular disease is among the leading causes of death in western industrial nations. 3D rotational angiography delivers indispensable information on vessel morphology and pathology. Physicians make use of this to analyze vessel geometry in detail, i.e. vessel diameters, location and size of aneurysms, to come up with a clinical decision. 3D segmentation is a crucial step in this pipeline. Although a lot of different methods are available nowadays, all of them lack a method to validate the results for the individual patient. Therefore, we propose a novel 2D digital subtraction angiography (DSA)-driven 3D vessel segmentation and validation framework. 2D DSA projections are clinically considered as gold standard when it comes to measurements of vessel diameter or the neck size of aneurysms. An ellipsoid vessel model is applied to deliver the initial 3D segmentation. To assess the accuracy of the 3D vessel segmentation, its forward projections are iteratively overlaid with the corresponding 2D DSA projections. Local vessel discrepancies are modeled by a global 2D/3D optimization function to adjust the 3D vessel segmentation toward the 2D vessel contours. Our framework has been evaluated on phantom data as well as on ten patient datasets. Three 2D DSA projections from varying viewing angles have been used for each dataset. The novel 2D driven 3D vessel segmentation approach shows superior results against state-of-the-art segmentations like region growing, i.e. an improvement of 7.2% points in precision and 5.8% points for the Dice coefficient. This method opens up future clinical applications requiring the greatest vessel accuracy, e.g. computational fluid dynamic modeling.

  10. From 3D view to 3D print

    NASA Astrophysics Data System (ADS)

    Dima, M.; Farisato, G.; Bergomi, M.; Viotto, V.; Magrin, D.; Greggio, D.; Farinato, J.; Marafatto, L.; Ragazzoni, R.; Piazza, D.

    2014-08-01

    In the last few years 3D printing is getting more and more popular and used in many fields going from manufacturing to industrial design, architecture, medical support and aerospace. 3D printing is an evolution of bi-dimensional printing, which allows to obtain a solid object from a 3D model, realized with a 3D modelling software. The final product is obtained using an additive process, in which successive layers of material are laid down one over the other. A 3D printer allows to realize, in a simple way, very complex shapes, which would be quite difficult to be produced with dedicated conventional facilities. Thanks to the fact that the 3D printing is obtained superposing one layer to the others, it doesn't need any particular work flow and it is sufficient to simply draw the model and send it to print. Many different kinds of 3D printers exist based on the technology and material used for layer deposition. A common material used by the toner is ABS plastics, which is a light and rigid thermoplastic polymer, whose peculiar mechanical properties make it diffusely used in several fields, like pipes production and cars interiors manufacturing. I used this technology to create a 1:1 scale model of the telescope which is the hardware core of the space small mission CHEOPS (CHaracterising ExOPlanets Satellite) by ESA, which aims to characterize EXOplanets via transits observations. The telescope has a Ritchey-Chrétien configuration with a 30cm aperture and the launch is foreseen in 2017. In this paper, I present the different phases for the realization of such a model, focusing onto pros and cons of this kind of technology. For example, because of the finite printable volume (10×10×12 inches in the x, y and z directions respectively), it has been necessary to split the largest parts of the instrument in smaller components to be then reassembled and post-processed. A further issue is the resolution of the printed material, which is expressed in terms of layers

  11. NASA Provides a 3-D Look at Typhoon Chaba

    NASA Video Gallery

    This 3-D flyby animation of Typhoon Chaba was created using data from NASA/JAXA's Global Precipitation Measurement mission or GPM core satellite. On Oct. 2, the GPM satellite saw some precipitation...

  12. YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters

    NASA Astrophysics Data System (ADS)

    Schild, Jonas; Seele, Sven; Masuch, Maic

    2012-03-01

    Along with the success of the digitally revived stereoscopic cinema, events beyond 3D movies become attractive for movie theater operators, i.e. interactive 3D games. In this paper, we present a case that explores possible challenges and solutions for interactive 3D games to be played by a movie theater audience. We analyze the setting and showcase current issues related to lighting and interaction. Our second focus is to provide gameplay mechanics that make special use of stereoscopy, especially depth-based game design. Based on these results, we present YouDash3D, a game prototype that explores public stereoscopic gameplay in a reduced kiosk setup. It features live 3D HD video stream of a professional stereo camera rig rendered in a real-time game scene. We use the effect to place the stereoscopic effigies of players into the digital game. The game showcases how stereoscopic vision can provide for a novel depth-based game mechanic. Projected trigger zones and distributed clusters of the audience video allow for easy adaptation to larger audiences and 3D movie theater gaming.

  13. Remote 3D Medical Consultation

    NASA Astrophysics Data System (ADS)

    Welch, Greg; Sonnenwald, Diane H.; Fuchs, Henry; Cairns, Bruce; Mayer-Patel, Ketan; Yang, Ruigang; State, Andrei; Towles, Herman; Ilie, Adrian; Krishnan, Srinivas; Söderholm, Hanna M.

    Two-dimensional (2D) video-based telemedical consultation has been explored widely in the past 15-20 years. Two issues that seem to arise in most relevant case studies are the difficulty associated with obtaining the desired 2D camera views, and poor depth perception. To address these problems we are exploring the use of a small array of cameras to synthesize a spatially continuous range of dynamic three-dimensional (3D) views of a remote environment and events. The 3D views can be sent across wired or wireless networks to remote viewers with fixed displays or mobile devices such as a personal digital assistant (PDA). The viewpoints could be specified manually or automatically via user head or PDA tracking, giving the remote viewer virtual head- or hand-slaved (PDA-based) remote cameras for mono or stereo viewing. We call this idea remote 3D medical consultation (3DMC). In this article we motivate and explain the vision for 3D medical consultation; we describe the relevant computer vision/graphics, display, and networking research; we present a proof-of-concept prototype system; and we present some early experimental results supporting the general hypothesis that 3D remote medical consultation could offer benefits over conventional 2D televideo.

  14. Speaking Volumes About 3-D

    NASA Technical Reports Server (NTRS)

    2002-01-01

    In 1999, Genex submitted a proposal to Stennis Space Center for a volumetric 3-D display technique that would provide multiple users with a 360-degree perspective to simultaneously view and analyze 3-D data. The futuristic capabilities of the VolumeViewer(R) have offered tremendous benefits to commercial users in the fields of medicine and surgery, air traffic control, pilot training and education, computer-aided design/computer-aided manufacturing, and military/battlefield management. The technology has also helped NASA to better analyze and assess the various data collected by its satellite and spacecraft sensors. Genex capitalized on its success with Stennis by introducing two separate products to the commercial market that incorporate key elements of the 3-D display technology designed under an SBIR contract. The company Rainbow 3D(R) imaging camera is a novel, three-dimensional surface profile measurement system that can obtain a full-frame 3-D image in less than 1 second. The third product is the 360-degree OmniEye(R) video system. Ideal for intrusion detection, surveillance, and situation management, this unique camera system offers a continuous, panoramic view of a scene in real time.

  15. 3-D Force-balanced Magnetospheric Configurations

    SciTech Connect

    Sorin Zaharia; C.Z. Cheng; K. Maezawa

    2003-02-10

    The knowledge of plasma pressure is essential for many physics applications in the magnetosphere, such as computing magnetospheric currents and deriving magnetosphere-ionosphere coupling. A thorough knowledge of the 3-D pressure distribution has however eluded the community, as most in-situ pressure observations are either in the ionosphere or the equatorial region of the magnetosphere. With the assumption of pressure isotropy there have been attempts to obtain the pressure at different locations by either (a) mapping observed data (e.g., in the ionosphere) along the field lines of an empirical magnetospheric field model or (b) computing a pressure profile in the equatorial plane (in 2-D) or along the Sun-Earth axis (in 1-D) that is in force balance with the magnetic stresses of an empirical model. However, the pressure distributions obtained through these methods are not in force balance with the empirical magnetic field at all locations. In order to find a global 3-D plasma pressure distribution in force balance with the magnetospheric magnetic field, we have developed the MAG-3D code, that solves the 3-D force balance equation J x B = (upside-down delta) P computationally. Our calculation is performed in a flux coordinate system in which the magnetic field is expressed in terms of Euler potentials as B = (upside-down delta) psi x (upside-down delta) alpha. The pressure distribution, P = P(psi,alpha), is prescribed in the equatorial plane and is based on satellite measurements. In addition, computational boundary conditions for y surfaces are imposed using empirical field models. Our results provide 3-D distributions of magnetic field and plasma pressure as well as parallel and transverse currents for both quiet-time and disturbed magnetospheric conditions.

  16. 3D-Printed Microfluidics.

    PubMed

    Au, Anthony K; Huynh, Wilson; Horowitz, Lisa F; Folch, Albert

    2016-03-14

    The advent of soft lithography allowed for an unprecedented expansion in the field of microfluidics. However, the vast majority of PDMS microfluidic devices are still made with extensive manual labor, are tethered to bulky control systems, and have cumbersome user interfaces, which all render commercialization difficult. On the other hand, 3D printing has begun to embrace the range of sizes and materials that appeal to the developers of microfluidic devices. Prior to fabrication, a design is digitally built as a detailed 3D CAD file. The design can be assembled in modules by remotely collaborating teams, and its mechanical and fluidic behavior can be simulated using finite-element modeling. As structures are created by adding materials without the need for etching or dissolution, processing is environmentally friendly and economically efficient. We predict that in the next few years, 3D printing will replace most PDMS and plastic molding techniques in academia.

  17. The EISCAT_3D Science Case

    NASA Astrophysics Data System (ADS)

    Tjulin, A.; Mann, I.; McCrea, I.; Aikio, A. T.

    2013-05-01

    EISCAT_3D will be a world-leading international research infrastructure using the incoherent scatter technique to study the atmosphere in the Fenno-Scandinavian Arctic and to investigate how the Earth's atmosphere is coupled to space. The EISCAT_3D phased-array multistatic radar system will be operated by EISCAT Scientific Association and thus be an integral part of an organisation that has successfully been running incoherent scatter radars for more than thirty years. The baseline design of the radar system contains a core site with transmitting and receiving capabilities located close to the intersection of the Swedish, Norwegian and Finnish borders and five receiving sites located within 50 to 250 km from the core. The EISCAT_3D project is currently in its Preparatory Phase and can smoothly transit into implementation in 2014, provided sufficient funding. Construction can start 2016 and first operations in 2018. The EISCAT_3D Science Case is prepared as part of the Preparatory Phase. It is regularly updated with annual new releases, and it aims at being a common document for the whole future EISCAT_3D user community. The areas covered by the Science Case are atmospheric physics and global change; space and plasma physics; solar system research; space weather and service applications; and radar techniques, new methods for coding and analysis. Two of the aims for EISCAT_3D are to understand the ways natural variability in the upper atmosphere, imposed by the Sun-Earth system, can influence the middle and lower atmosphere, and to improve the predictivity of atmospheric models by providing higher resolution observations to replace the current parametrised input. Observations by EISCAT_3D will also be used to monitor the direct effects from the Sun on the ionosphere-atmosphere system and those caused by solar wind magnetosphere-ionosphere interaction. In addition, EISCAT_3D will be used for remote sensing the large-scale behaviour of the magnetosphere from its

  18. 3D cartography of the Alpine Arc

    NASA Astrophysics Data System (ADS)

    Vouillamoz, N.; Sue, C.; Champagnac, J. D.; Calcagno, P.

    2012-04-01

    We present a 3D cartography of the alpine arc, a highly non-cylindrical mountain belt, built 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-dimentional cartography that would be used as input for further alpine studies.

  19. 3D Computations and Experiments

    SciTech Connect

    Couch, R; Faux, D; Goto, D; Nikkel, D

    2004-04-05

    This project consists of two activities. Task A, Simulations and Measurements, combines all the material model development and associated numerical work with the materials-oriented experimental activities. The goal of this effort is to provide an improved understanding of dynamic material properties and to provide accurate numerical representations of those properties for use in analysis codes. Task B, ALE3D Development, involves general development activities in the ALE3D code with the focus of improving simulation capabilities for problems of mutual interest to DoD and DOE. Emphasis is on problems involving multi-phase flow, blast loading of structures and system safety/vulnerability studies.

  20. 3-D visualization of ensemble weather forecasts - Part 1: The visualization tool Met.3D (version 1.0)

    NASA Astrophysics Data System (ADS)

    Rautenhaus, M.; Kern, M.; Schäfler, A.; Westermann, R.

    2015-02-01

    We present Met.3D, a new open-source tool for the interactive 3-D visualization of numerical ensemble weather predictions. The tool has been developed to support weather forecasting during aircraft-based atmospheric field campaigns, however, is applicable to further forecasting, research and teaching activities. Our work approaches challenging topics related to the visual analysis of numerical atmospheric model output - 3-D visualization, ensemble visualization, and how both can be used in a meaningful way suited to weather forecasting. Met.3D builds a bridge from proven 2-D visualization methods commonly used in meteorology to 3-D visualization by combining both visualization types in a 3-D context. We address the issue of spatial perception in the 3-D view and present approaches to using the ensemble to allow the user to assess forecast uncertainty. Interactivity is key to our approach. Met.3D uses modern graphics technology to achieve interactive visualization on standard consumer hardware. The tool supports forecast data from the European Centre for Medium Range Weather Forecasts and can operate directly on ECMWF hybrid sigma-pressure level grids. We describe the employed visualization algorithms, and analyse the impact of the ECMWF grid topology on computing 3-D ensemble statistical quantitites. Our techniques are demonstrated with examples from the T-NAWDEX-Falcon 2012 campaign.

  1. Met.3D - a new open-source tool for interactive 3D visualization of ensemble weather forecasts

    NASA Astrophysics Data System (ADS)

    Rautenhaus, Marc; Kern, Michael; Schäfler, Andreas; Westermann, Rüdiger

    2015-04-01

    We introduce Met.3D, a new open-source tool for the interactive 3D visualization of numerical ensemble weather predictions. The tool has been developed to support weather forecasting during aircraft-based atmospheric field campaigns, however, is applicable to further forecasting, research and teaching activities. Our work approaches challenging topics related to the visual analysis of numerical atmospheric model output -- 3D visualisation, ensemble visualization, and how both can be used in a meaningful way suited to weather forecasting. Met.3D builds a bridge from proven 2D visualization methods commonly used in meteorology to 3D visualization by combining both visualization types in a 3D context. It implements methods that address the issue of spatial perception in the 3D view as well as approaches to using the ensemble in order to assess forecast uncertainty. Interactivity is key to the Met.3D approach. The tool uses modern graphics hardware technology to achieve interactive visualization of present-day numerical weather prediction datasets on standard consumer hardware. Met.3D supports forecast data from the European Centre for Medium Range Weather Forecasts and operates directly on ECMWF hybrid sigma-pressure level grids. In this presentation, we provide an overview of the software --illustrated with short video examples--, and give information on its availability.

  2. 3D-Pathology: a real-time system for quantitative diagnostic pathology and visualisation in 3D

    NASA Astrophysics Data System (ADS)

    Gottrup, Christian; Beckett, Mark G.; Hager, Henrik; Locht, Peter

    2005-02-01

    This paper presents the results of the 3D-Pathology project conducted under the European EC Framework 5. The aim of the project was, through the application of 3D image reconstruction and visualization techniques, to improve the diagnostic and prognostic capabilities of medical personnel when analyzing pathological specimens using transmitted light microscopy. A fully automated, computer-controlled microscope system has been developed to capture 3D images of specimen content. 3D image reconstruction algorithms have been implemented and applied to the acquired volume data in order to facilitate the subsequent 3D visualization of the specimen. Three potential application fields, immunohistology, cromogenic in situ hybridization (CISH) and cytology, have been tested using the prototype system. For both immunohistology and CISH, use of the system furnished significant additional information to the pathologist.

  3. 3D Printing of Conductive Complex Structures with In Situ Generation of Silver Nanoparticles.

    PubMed

    Fantino, Erika; Chiappone, Annalisa; Roppolo, Ignazio; Manfredi, Diego; Bongiovanni, Roberta; Pirri, Candido Fabrizio; Calignano, Flaviana

    2016-05-01

    Coupling the photoreduction of a metal precursor with 3D-printing technology is shown to allow the fabrication of conductive 3D hybrid structures consisting of metal nanoparticles and organic polymers shaped in complex multilayered architectures. 3D conductive structures are fabricated incorporating silver nitrate into a photocurable oligomer in the presence of suitable photoinitiators and exposing them to a digital light system.

  4. Making Inexpensive 3-D Models

    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…

  5. SNL3dFace

    2007-07-20

    This software distribution contains MATLAB and C++ code to enable identity verification using 3D images that may or may not contain a texture component. The code is organized to support system performance testing and system capability demonstration through the proper configuration of the available user interface. Using specific algorithm parameters the face recognition system has been demonstrated to achieve a 96.6% verification rate (Pd) at 0.001 false alarm rate. The system computes robust facial featuresmore » of a 3D normalized face using Principal Component Analysis (PCA) and Fisher Linear Discriminant Analysis (FLDA). A 3D normalized face is obtained by alighning each face, represented by a set of XYZ coordinated, to a scaled reference face using the Iterative Closest Point (ICP) algorithm. The scaled reference face is then deformed to the input face using an iterative framework with parameters that control the deformed surface regulation an rate of deformation. A variety of options are available to control the information that is encoded by the PCA. Such options include the XYZ coordinates, the difference of each XYZ coordinates from the reference, the Z coordinate, the intensity/texture values, etc. In addition to PCA/FLDA feature projection this software supports feature matching to obtain similarity matrices for performance analysis. In addition, this software supports visualization of the STL, MRD, 2D normalized, and PCA synthetic representations in a 3D environment.« less

  6. SNL3dFace

    SciTech Connect

    Russ, Trina; Koch, Mark; Koudelka, Melissa; Peters, Ralph; Little, Charles; Boehnen, Chris; Peters, Tanya

    2007-07-20

    This software distribution contains MATLAB and C++ code to enable identity verification using 3D images that may or may not contain a texture component. The code is organized to support system performance testing and system capability demonstration through the proper configuration of the available user interface. Using specific algorithm parameters the face recognition system has been demonstrated to achieve a 96.6% verification rate (Pd) at 0.001 false alarm rate. The system computes robust facial features of a 3D normalized face using Principal Component Analysis (PCA) and Fisher Linear Discriminant Analysis (FLDA). A 3D normalized face is obtained by alighning each face, represented by a set of XYZ coordinated, to a scaled reference face using the Iterative Closest Point (ICP) algorithm. The scaled reference face is then deformed to the input face using an iterative framework with parameters that control the deformed surface regulation an rate of deformation. A variety of options are available to control the information that is encoded by the PCA. Such options include the XYZ coordinates, the difference of each XYZ coordinates from the reference, the Z coordinate, the intensity/texture values, etc. In addition to PCA/FLDA feature projection this software supports feature matching to obtain similarity matrices for performance analysis. In addition, this software supports visualization of the STL, MRD, 2D normalized, and PCA synthetic representations in a 3D environment.

  7. 3D Printing: Exploring Capabilities

    ERIC Educational Resources Information Center

    Samuels, Kyle; Flowers, Jim

    2015-01-01

    As 3D printers become more affordable, schools are using them in increasing numbers. They fit well with the emphasis on product design in technology and engineering education, allowing students to create high-fidelity physical models to see and test different iterations in their product designs. They may also help students to "think in three…

  8. 3-D magnetic field calculations for wiggglers using MAGNUS-3D

    SciTech Connect

    Pissanetzky, S.; Tompkins, P.

    1988-01-01

    The recent but steady trend toward increased magnetic and geometric complexity in the design of wigglers and undulators, of which tapered wigglers, hybrid structures, laced electromagnetic wigglers, magnetic cladding, twisters and magic structures are examples, has caused a need for reliable 3-D computer models and a better understanding of the behavior of magnetic systems in three dimensions. The capabilities of the MAGNUS-3D Group of Programs are ideally suited to solve this class of problems and provide insight into 3-D effects. MAGNUS-3D can solve any problem of Magnetostatics involving permanent magnets, linear or nonlinear ferromagnetic materials and electric conductors of any shape in space. The magnetic properties of permanent magnets are described by the complete nonlinear demagnetization curve as provided by the manufacturer, or, at the user's choice, by a simpler approximation involving the coercive force, the residual induction and the direction of magnetization. The ferromagnetic materials are described by a magnetization table and an accurate interpolation relation. An internal library with properties of common industrial steels is available. The conductors are independent of the mesh and are described in terms of conductor elements from an internal library.

  9. TACO3D. 3-D Finite Element Heat Transfer Code

    SciTech Connect

    Mason, W.E.

    1992-03-04

    TACO3D is a three-dimensional, finite-element program for heat transfer analysis. An extension of the two-dimensional TACO program, it can perform linear and nonlinear analyses and can be used to solve either transient or steady-state problems. The program accepts time-dependent or temperature-dependent material properties, and materials may be isotropic or orthotropic. A variety of time-dependent and temperature-dependent boundary conditions and loadings are available including temperature, flux, convection, and radiation boundary conditions and internal heat generation. Additional specialized features treat enclosure radiation, bulk nodes, and master/slave internal surface conditions (e.g., contact resistance). Data input via a free-field format is provided. A user subprogram feature allows for any type of functional representation of any independent variable. A profile (bandwidth) minimization option is available. The code is limited to implicit time integration for transient solutions. TACO3D has no general mesh generation capability. Rows of evenly-spaced nodes and rows of sequential elements may be generated, but the program relies on separate mesh generators for complex zoning. TACO3D does not have the ability to calculate view factors internally. Graphical representation of data in the form of time history and spatial plots is provided through links to the POSTACO and GRAPE postprocessor codes.

  10. Identifying novel sequence variants of RNA 3D motifs

    PubMed Central

    Zirbel, Craig L.; Roll, James; Sweeney, Blake A.; Petrov, Anton I.; Pirrung, Meg; Leontis, Neocles B.

    2015-01-01

    Predicting RNA 3D structure from sequence is a major challenge in biophysics. An important sub-goal is accurately identifying recurrent 3D motifs from RNA internal and hairpin loop sequences extracted from secondary structure (2D) diagrams. We have developed and validated new probabilistic models for 3D motif sequences based on hybrid Stochastic Context-Free Grammars and Markov Random Fields (SCFG/MRF). The SCFG/MRF models are constructed using atomic-resolution RNA 3D structures. To parameterize each model, we use all instances of each motif found in the RNA 3D Motif Atlas and annotations of pairwise nucleotide interactions generated by the FR3D software. Isostericity relations between non-Watson–Crick basepairs are used in scoring sequence variants. SCFG techniques model nested pairs and insertions, while MRF ideas handle crossing interactions and base triples. We use test sets of randomly-generated sequences to set acceptance and rejection thresholds for each motif group and thus control the false positive rate. Validation was carried out by comparing results for four motif groups to RMDetect. The software developed for sequence scoring (JAR3D) is structured to automatically incorporate new motifs as they accumulate in the RNA 3D Motif Atlas when new structures are solved and is available free for download. PMID:26130723

  11. A Game Theoretic Optimization Method for Energy Efficient Global Connectivity in Hybrid Wireless Sensor Networks

    PubMed Central

    Lee, JongHyup; Pak, Dohyun

    2016-01-01

    For practical deployment of wireless sensor networks (WSN), WSNs construct clusters, where a sensor node communicates with other nodes in its cluster, and a cluster head support connectivity between the sensor nodes and a sink node. In hybrid WSNs, cluster heads have cellular network interfaces for global connectivity. However, when WSNs are active and the load of cellular networks is high, the optimal assignment of cluster heads to base stations becomes critical. Therefore, in this paper, we propose a game theoretic model to find the optimal assignment of base stations for hybrid WSNs. Since the communication and energy cost is different according to cellular systems, we devise two game models for TDMA/FDMA and CDMA systems employing power prices to adapt to the varying efficiency of recent wireless technologies. The proposed model is defined on the assumptions of the ideal sensing field, but our evaluation shows that the proposed model is more adaptive and energy efficient than local selections. PMID:27589743

  12. A Game Theoretic Optimization Method for Energy Efficient Global Connectivity in Hybrid Wireless Sensor Networks.

    PubMed

    Lee, JongHyup; Pak, Dohyun

    2016-01-01

    For practical deployment of wireless sensor networks (WSN), WSNs construct clusters, where a sensor node communicates with other nodes in its cluster, and a cluster head support connectivity between the sensor nodes and a sink node. In hybrid WSNs, cluster heads have cellular network interfaces for global connectivity. However, when WSNs are active and the load of cellular networks is high, the optimal assignment of cluster heads to base stations becomes critical. Therefore, in this paper, we propose a game theoretic model to find the optimal assignment of base stations for hybrid WSNs. Since the communication and energy cost is different according to cellular systems, we devise two game models for TDMA/FDMA and CDMA systems employing power prices to adapt to the varying efficiency of recent wireless technologies. The proposed model is defined on the assumptions of the ideal sensing field, but our evaluation shows that the proposed model is more adaptive and energy efficient than local selections. PMID:27589743

  13. A Game Theoretic Optimization Method for Energy Efficient Global Connectivity in Hybrid Wireless Sensor Networks.

    PubMed

    Lee, JongHyup; Pak, Dohyun

    2016-08-29

    For practical deployment of wireless sensor networks (WSN), WSNs construct clusters, where a sensor node communicates with other nodes in its cluster, and a cluster head support connectivity between the sensor nodes and a sink node. In hybrid WSNs, cluster heads have cellular network interfaces for global connectivity. However, when WSNs are active and the load of cellular networks is high, the optimal assignment of cluster heads to base stations becomes critical. Therefore, in this paper, we propose a game theoretic model to find the optimal assignment of base stations for hybrid WSNs. Since the communication and energy cost is different according to cellular systems, we devise two game models for TDMA/FDMA and CDMA systems employing power prices to adapt to the varying efficiency of recent wireless technologies. The proposed model is defined on the assumptions of the ideal sensing field, but our evaluation shows that the proposed model is more adaptive and energy efficient than local selections.

  14. Global hybrid simulation of the solar wind interaction with the dayside of Venus

    SciTech Connect

    Moore, K.R.; Thomas, V.A.; McComas, D.J. )

    1991-05-01

    The authors present a 3-dimensional global hybrid simulation of the interaction of the solar wind with the entire dayside of Venus. The model obstacle is half the size of Venus, and planetary ion mass loading is included self-consistently. Results are compared to observations as well as to results from gasdynamic convected field modeling. Magnetic field magnitudes and bulk flow speeds along the planet-Sun line are comparable in both models, but only the hybrid model reproduces the experimentally observed magnetic barrier proton density depletions. The finite gyroradius of the planetary pickup ions causes a number density asymmetry in the direction of the convective ({minus}V {times} B) electric field, as predicted and observed. Mass addition consistent with photoionization of the planetary neutral hot oxygen corona has little effect on the geometry of the shock, including the subsolar and terminator shock altitudes. Mass addition rates well in excess of likely values are required to significantly affect the model shock geometry. The hybrid model results imply that oxygen ions originating deep within the dayside Venus magnetic barrier are nearly fluidlike while oxygen ions produced higher on the dayside, at much lower densities, behave more as test particles. Gasdynamic modeling incorporating both fluid and test particle mass addition reproduces the O{sup +} terminator escape flux (a few times 10{sup 24} s{sup {minus}1}) found in the hybrid model and inferred from observations, but underestimates the escape region spatial extent. The hybrid model predictions include a shock asymmetry dependent on the upstream IMF orientation, asymmetries in the magnetic barrier position and field magnitude, an asymmetry in pickup ion speed altitude profiles, and a finite gyroradius effect asymmetry in pickup ion number density caused by field draping.

  15. Forensic 3D scene reconstruction

    NASA Astrophysics Data System (ADS)

    Little, Charles Q.; Small, Daniel E.; Peters, Ralph R.; Rigdon, J. B.

    2000-05-01

    Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a fieldable prototype of a fast, accurate, 3D measurement and imaging system that would support law enforcement agents to quickly document and accurately record a crime scene.

  16. 3D Printable Graphene Composite.

    PubMed

    Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong

    2015-07-08

    In human being's history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today's personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite's linear thermal coefficient is below 75 ppm·°C(-1) from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process.

  17. Forensic 3D Scene Reconstruction

    SciTech Connect

    LITTLE,CHARLES Q.; PETERS,RALPH R.; RIGDON,J. BRIAN; SMALL,DANIEL E.

    1999-10-12

    Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and contribute quantitative measurements such as accurate relative positioning of crime scene objects, would be an asset to law enforcement agents in collecting and recording significant forensic data. The purpose of this project is to develop a feasible prototype of a fast, accurate, 3D measurement and imaging system that would support law enforcement agents to quickly document and accurately record a crime scene.

  18. 3D Printed Robotic Hand

    NASA Technical Reports Server (NTRS)

    Pizarro, Yaritzmar Rosario; Schuler, Jason M.; Lippitt, Thomas C.

    2013-01-01

    Dexterous robotic hands are changing the way robots and humans interact and use common tools. Unfortunately, the complexity of the joints and actuations drive up the manufacturing cost. Some cutting edge and commercially available rapid prototyping machines now have the ability to print multiple materials and even combine these materials in the same job. A 3D model of a robotic hand was designed using Creo Parametric 2.0. Combining "hard" and "soft" materials, the model was printed on the Object Connex350 3D printer with the purpose of resembling as much as possible the human appearance and mobility of a real hand while needing no assembly. After printing the prototype, strings where installed as actuators to test mobility. Based on printing materials, the manufacturing cost of the hand was $167, significantly lower than other robotic hands without the actuators since they have more complex assembly processes.

  19. 3D light scanning macrography.

    PubMed

    Huber, D; Keller, M; Robert, D

    2001-08-01

    The technique of 3D light scanning macrography permits the non-invasive surface scanning of small specimens at magnifications up to 200x. Obviating both the problem of limited depth of field inherent to conventional close-up macrophotography and the metallic coating required by scanning electron microscopy, 3D light scanning macrography provides three-dimensional digital images of intact specimens without the loss of colour, texture and transparency information. This newly developed technique offers a versatile, portable and cost-efficient method for the non-invasive digital and photographic documentation of small objects. Computer controlled device operation and digital image acquisition facilitate fast and accurate quantitative morphometric investigations, and the technique offers a broad field of research and educational applications in biological, medical and materials sciences. PMID:11489078

  20. [Real time 3D echocardiography

    NASA Technical Reports Server (NTRS)

    Bauer, F.; Shiota, T.; Thomas, J. D.

    2001-01-01

    Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients.

  1. [Real time 3D echocardiography].

    PubMed

    Bauer, F; Shiota, T; Thomas, J D

    2001-07-01

    Three-dimensional representation of the heart is an old concern. Usually, 3D reconstruction of the cardiac mass is made by successive acquisition of 2D sections, the spatial localisation and orientation of which require complex guiding systems. More recently, the concept of volumetric acquisition has been introduced. A matricial emitter-receiver probe complex with parallel data processing provides instantaneous of a pyramidal 64 degrees x 64 degrees volume. The image is restituted in real time and is composed of 3 planes (planes B and C) which can be displaced in all spatial directions at any time during acquisition. The flexibility of this system of acquisition allows volume and mass measurement with greater accuracy and reproducibility, limiting inter-observer variability. Free navigation of the planes of investigation allows reconstruction for qualitative and quantitative analysis of valvular heart disease and other pathologies. Although real time 3D echocardiography is ready for clinical usage, some improvements are still necessary to improve its conviviality. Then real time 3D echocardiography could be the essential tool for understanding, diagnosis and management of patients. PMID:11494630

  2. DYNA3D. Explicit 3-d Hydrodynamic FEM Program

    SciTech Connect

    Whirley, R.G.; Englemann, B.E. )

    1993-11-30

    DYNA3D is an explicit, three-dimensional, finite element program for analyzing the large deformation dynamic response of inelastic solids and structures. DYNA3D contains 30 material models and 10 equations of state (EOS) to cover a wide range of material behavior. The material models implemented are: elastic, orthotropic elastic, kinematic/isotropic plasticity, thermoelastoplastic, soil and crushable foam, linear viscoelastic, Blatz-Ko rubber, high explosive burn, hydrodynamic without deviatoric stresses, elastoplastic hydrodynamic, temperature-dependent elastoplastic, isotropic elastoplastic, isotropic elastoplastic with failure, soil and crushable foam with failure, Johnson/Cook plasticity model, pseudo TENSOR geological model, elastoplastic with fracture, power law isotropic plasticity, strain rate dependent plasticity, rigid, thermal orthotropic, composite damage model, thermal orthotropic with 12 curves, piecewise linear isotropic plasticity, inviscid two invariant geologic cap, orthotropic crushable model, Moonsy-Rivlin rubber, resultant plasticity, closed form update shell plasticity, and Frazer-Nash rubber model. The hydrodynamic material models determine only the deviatoric stresses. Pressure is determined by one of 10 equations of state including linear polynomial, JWL high explosive, Sack Tuesday high explosive, Gruneisen, ratio of polynomials, linear polynomial with energy deposition, ignition and growth of reaction in HE, tabulated compaction, tabulated, and TENSOR pore collapse. DYNA3D generates three binary output databases. One contains information for complete states at infrequent intervals; 50 to 100 states is typical. The second contains information for a subset of nodes and elements at frequent intervals; 1,000 to 10,000 states is typical. The last contains interface data for contact surfaces.

  3. GPU-Accelerated Denoising in 3D (GD3D)

    2013-10-01

    The raw computational power GPU Accelerators enables fast denoising of 3D MR images using bilateral filtering, anisotropic diffusion, and non-local means. This software addresses two facets of this promising application: what tuning is necessary to achieve optimal performance on a modern GPU? And what parameters yield the best denoising results in practice? To answer the first question, the software performs an autotuning step to empirically determine optimal memory blocking on the GPU. To answer themore » second, it performs a sweep of algorithm parameters to determine the combination that best reduces the mean squared error relative to a noiseless reference image.« less

  4. Magmatic Systems in 3-D

    NASA Astrophysics Data System (ADS)

    Kent, G. M.; Harding, A. J.; Babcock, J. M.; Orcutt, J. A.; Bazin, S.; Singh, S.; Detrick, R. S.; Canales, J. P.; Carbotte, S. M.; Diebold, J.

    2002-12-01

    Multichannel seismic (MCS) images of crustal magma chambers are ideal targets for advanced visualization techniques. In the mid-ocean ridge environment, reflections originating at the melt-lens are well separated from other reflection boundaries, such as the seafloor, layer 2A and Moho, which enables the effective use of transparency filters. 3-D visualization of seismic reflectivity falls into two broad categories: volume and surface rendering. Volumetric-based visualization is an extremely powerful approach for the rapid exploration of very dense 3-D datasets. These 3-D datasets are divided into volume elements or voxels, which are individually color coded depending on the assigned datum value; the user can define an opacity filter to reject plotting certain voxels. This transparency allows the user to peer into the data volume, enabling an easy identification of patterns or relationships that might have geologic merit. Multiple image volumes can be co-registered to look at correlations between two different data types (e.g., amplitude variation with offsets studies), in a manner analogous to draping attributes onto a surface. In contrast, surface visualization of seismic reflectivity usually involves producing "fence" diagrams of 2-D seismic profiles that are complemented with seafloor topography, along with point class data, draped lines and vectors (e.g. fault scarps, earthquake locations and plate-motions). The overlying seafloor can be made partially transparent or see-through, enabling 3-D correlations between seafloor structure and seismic reflectivity. Exploration of 3-D datasets requires additional thought when constructing and manipulating these complex objects. As numbers of visual objects grow in a particular scene, there is a tendency to mask overlapping objects; this clutter can be managed through the effective use of total or partial transparency (i.e., alpha-channel). In this way, the co-variation between different datasets can be investigated

  5. Application of Hybrid Laminar Flow Control to Global Range Military Transport Aircraft

    NASA Technical Reports Server (NTRS)

    Lange, Roy H.

    1988-01-01

    A study was conducted to evaluate the application of hybrid laminar flow control (HLFC) to global range military transport aircraft. The global mission included the capability to transport 132,500 pounds of payload 6500 nautical miles, land and deliver the payload and without refueling return 6500 nautical miles to a friendly airbase. The preliminary design studies show significant performance benefits obtained for the HLFC aircraft as compared to counterpart turbulent flow aircraft. The study results at M=0.77 show that the largest benefits of HLFC are obtained with a high wing with engines on the wing configuration. As compared with the turbulent flow baseline aircraft, the high wing HLFC aircraft shows 17 percent reduction in fuel burned, 19.2 percent increase in lift-to-drag ratio, an insignificant increase in operating weight, and a 7.4 percent reduction in gross weight.

  6. Impact of EnVar hybrid assimilation using EnKF ensembles

    NASA Astrophysics Data System (ADS)

    Prasad, V. S.; Johny, C. J.; Sodhi, Jagdeep Singh; Rajagopal, E. N.

    2016-05-01

    Performance of an EnVar hybrid data assimilation system based on 3D Var NGFS (NCMRWF Global Forecast System) of T574 configuration and Ensemble Kalman Filter is investigated. The experiment is conducted during the Indian monsoon season (June-September) 2015 and compared against operational GSI 3D Var system. Two way coupled dual resolution hybrid system with 80 member ensemble of T254L64 configuration are used and forecasts are done for 10days. In hybrid experiment 75% weight is given to ensemble covariance and 25% for static covariance. The forecast skill of experiments over different spatial domains is compared against observations and respective analysis. The hybrid experiment produced significant improvement in forecasts compared to 3D Var in all fields except lower level temperature over tropical regions. Improvement is also seen in the prediction of extreme rainfall events. The prediction of monsoon onset and track of cyclone Ashobaa with hybrid and 3D var system is discussed.

  7. Global Hybrid Simulations of Solar Wind Interaction with the Hermean Magnetosphere

    NASA Astrophysics Data System (ADS)

    Omidi, N.; Russell, C. T.; Blanco-Cano, X.; Karimabadi, H.

    Mariner 10 observations suggest the Hermean magnetosphere has a terrestrial-like structure. From the theoretical point of view, until recently, no scaling laws regarding solar wind interaction with magnetic dipoles of various strength existed. As a result, it was not obvious as to whether the Hermean magnetosphere should be earth-like or not. Using global hybrid (kinetic ions, fluid electrons) simulations, we have demonstrated the presence of a spectrum of magnetospheric structures associated with dipoles of various strength. It was found that once the standoff distance of the magnetopause is greater than about 20 solar wind ion skin depth, the resulting magnetosphere is similar to that of the earth. In the case of Mercury, the standoff distance of the magnetopause is about 70-80 local solar wind ion skin depth and accordingly the magnetosphere should be terrestrial-like. Here, we present results from global hybrid simulations of solar wind interaction with the Hermean magnetosphere under a variety of interplanetary magnetic field (IMF) conditions. By virtue of their kinetic nature, these simulations can shed light on micro- and macrophysics of the ion foreshock, the bow shock, magnetosheath, magnetopause, lobe and the plasma sheet. After a brief review of these regions, we concentrate on the low and high latitude magnetopause and comparisons with the Mariner 10 data.

  8. Dynamic contrast-enhanced 3D photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Wong, Philip; Kosik, Ivan; Carson, Jeffrey J. L.

    2013-03-01

    Photoacoustic imaging (PAI) is a hybrid imaging modality that integrates the strengths from both optical imaging and acoustic imaging while simultaneously overcoming many of their respective weaknesses. In previous work, we reported on a real-time 3D PAI system comprised of a 32-element hemispherical array of transducers. Using the system, we demonstrated the ability to capture photoacoustic data, reconstruct a 3D photoacoustic image, and display select slices of the 3D image every 1.4 s, where each 3D image resulted from a single laser pulse. The present study aimed to exploit the rapid imaging speed of an upgraded 3D PAI system by evaluating its ability to perform dynamic contrast-enhanced imaging. The contrast dynamics can provide rich datasets that contain insight into perfusion, pharmacokinetics and physiology. We captured a series of 3D PA images of a flow phantom before and during injection of piglet and rabbit blood. Principal component analysis was utilized to classify the data according to its spatiotemporal information. The results suggested that this technique can be used to separate a sequence of 3D PA images into a series of images representative of main features according to spatiotemporal flow dynamics.

  9. Interactive 3D Mars Visualization

    NASA Technical Reports Server (NTRS)

    Powell, Mark W.

    2012-01-01

    The Interactive 3D Mars Visualization system provides high-performance, immersive visualization of satellite and surface vehicle imagery of Mars. The software can be used in mission operations to provide the most accurate position information for the Mars rovers to date. When integrated into the mission data pipeline, this system allows mission planners to view the location of the rover on Mars to 0.01-meter accuracy with respect to satellite imagery, with dynamic updates to incorporate the latest position information. Given this information so early in the planning process, rover drivers are able to plan more accurate drive activities for the rover than ever before, increasing the execution of science activities significantly. Scientifically, this 3D mapping information puts all of the science analyses to date into geologic context on a daily basis instead of weeks or months, as was the norm prior to this contribution. This allows the science planners to judge the efficacy of their previously executed science observations much more efficiently, and achieve greater science return as a result. The Interactive 3D Mars surface view is a Mars terrain browsing software interface that encompasses the entire region of exploration for a Mars surface exploration mission. The view is interactive, allowing the user to pan in any direction by clicking and dragging, or to zoom in or out by scrolling the mouse or touchpad. This set currently includes tools for selecting a point of interest, and a ruler tool for displaying the distance between and positions of two points of interest. The mapping information can be harvested and shared through ubiquitous online mapping tools like Google Mars, NASA WorldWind, and Worldwide Telescope.

  10. What Lies Ahead (3-D)

    NASA Technical Reports Server (NTRS)

    2004-01-01

    This 3-D cylindrical-perspective mosaic taken by the navigation camera on the Mars Exploration Rover Spirit on sol 82 shows the view south of the large crater dubbed 'Bonneville.' The rover will travel toward the Columbia Hills, seen here at the upper left. The rock dubbed 'Mazatzal' and the hole the rover drilled in to it can be seen at the lower left. The rover's position is referred to as 'Site 22, Position 32.' This image was geometrically corrected to make the horizon appear flat.

  11. Making Inexpensive 3-D Models

    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.

  12. 3D Printed Shelby Cobra

    SciTech Connect

    Love, Lonnie

    2015-01-09

    ORNL's newly printed 3D Shelby Cobra was showcased at the 2015 NAIAS in Detroit. This "laboratory on wheels" uses the Shelby Cobra design, celebrating the 50th anniversary of this model and honoring the first vehicle to be voted a national monument. The Shelby was printed at the Department of Energy’s Manufacturing Demonstration Facility at ORNL using the BAAM (Big Area Additive Manufacturing) machine and is intended as a “plug-n-play” laboratory on wheels. The Shelby will allow research and development of integrated components to be tested and enhanced in real time, improving the use of sustainable, digital manufacturing solutions in the automotive industry.

  13. The PRISM3D paleoenvironmental reconstruction

    USGS Publications Warehouse

    Dowsett, H.; Robinson, M.; Haywood, A.M.; Salzmann, U.; Hill, Daniel; Sohl, L.E.; Chandler, M.; Williams, Mark; Foley, K.; Stoll, D.K.

    2010-01-01

    The Pliocene Research, Interpretation and Synoptic Mapping (PRISM) paleoenvironmental reconstruction is an internally consistent and comprehensive global synthesis of a past interval of relatively warm and stable climate. It is regularly used in model studies that aim to better understand Pliocene climate, to improve model performance in future climate scenarios, and to distinguish model-dependent climate effects. The PRISM reconstruction is constantly evolving in order to incorporate additional geographic sites and environmental parameters, and is continuously refined by independent research findings. The new PRISM three dimensional (3D) reconstruction differs from previous PRISM reconstructions in that it includes a subsurface ocean temperature reconstruction, integrates geochemical sea surface temperature proxies to supplement the faunal-based temperature estimates, and uses numerical models for the first time to augment fossil data. Here we describe the components of PRISM3D and describe new findings specific to the new reconstruction. Highlights of the new PRISM3D reconstruction include removal of Hudson Bay and the Great Lakes and creation of open waterways in locations where the current bedrock elevation is less than 25m above modern sea level, due to the removal of the West Antarctic Ice Sheet and the reduction of the East Antarctic Ice Sheet. The mid-Piacenzian oceans were characterized by a reduced east-west temperature gradient in the equatorial Pacific, but PRISM3D data do not imply permanent El Niño conditions. The reduced equator-to-pole temperature gradient that characterized previous PRISM reconstructions is supported by significant displacement of vegetation belts toward the poles, is extended into the Arctic Ocean, and is confirmed by multiple proxies in PRISM3D. Arctic warmth coupled with increased dryness suggests the formation of warm and salty paleo North Atlantic Deep Water (NADW) and a more vigorous thermohaline circulation system that may

  14. 3D acoustic atmospheric tomography

    NASA Astrophysics Data System (ADS)

    Rogers, Kevin; Finn, Anthony

    2014-10-01

    This paper presents a method for tomographically reconstructing spatially varying 3D atmospheric temperature profiles and wind velocity fields based. Measurements of the acoustic signature measured onboard a small Unmanned Aerial Vehicle (UAV) are compared to ground-based observations of the same signals. The frequency-shifted signal variations are then used to estimate the acoustic propagation delay between the UAV and the ground microphones, which are also affected by atmospheric temperature and wind speed vectors along each sound ray path. The wind and temperature profiles are modelled as the weighted sum of Radial Basis Functions (RBFs), which also allow local meteorological measurements made at the UAV and ground receivers to supplement any acoustic observations. Tomography is used to provide a full 3D reconstruction/visualisation of the observed atmosphere. The technique offers observational mobility under direct user control and the capacity to monitor hazardous atmospheric environments, otherwise not justifiable on the basis of cost or risk. This paper summarises the tomographic technique and reports on the results of simulations and initial field trials. The technique has practical applications for atmospheric research, sound propagation studies, boundary layer meteorology, air pollution measurements, analysis of wind shear, and wind farm surveys.

  15. Gravitation in 3D Spacetime

    NASA Astrophysics Data System (ADS)

    Laubenstein, John; Cockream, Kandi

    2009-05-01

    3D spacetime was developed by the IWPD Scale Metrics (SM) team using a coordinate system that translates n dimensions to n-1. 4-vectors are expressed in 3D along with a scaling factor representing time. Time is not orthogonal to the three spatial dimensions, but rather in alignment with an object's axis-of-motion. We have defined this effect as the object's ``orientation'' (X). The SM orientation (X) is equivalent to the orientation of the 4-velocity vector positioned tangent to its worldline, where X-1=θ+1 and θ is the angle of the 4-vector relative to the axis-of -motion. Both 4-vectors and SM appear to represent valid conceptualizations of the relationship between space and time. Why entertain SM? Scale Metrics gravity is quantized and may suggest a path for the full unification of gravitation with quantum theory. SM has been tested against current observation and is in agreement with the age of the universe, suggests a physical relationship between dark energy and dark matter, is in agreement with the accelerating expansion rate of the universe, contributes to the understanding of the fine-structure constant and provides a physical explanation of relativistic effects.

  16. 3D printed bionic ears.

    PubMed

    Mannoor, Manu S; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A; Soboyejo, Winston O; Verma, Naveen; Gracias, David H; McAlpine, Michael C

    2013-06-12

    The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing.

  17. 3D medical thermography device

    NASA Astrophysics Data System (ADS)

    Moghadam, Peyman

    2015-05-01

    In this paper, a novel handheld 3D medical thermography system is introduced. The proposed system consists of a thermal-infrared camera, a color camera and a depth camera rigidly attached in close proximity and mounted on an ergonomic handle. As a practitioner holding the device smoothly moves it around the human body parts, the proposed system generates and builds up a precise 3D thermogram model by incorporating information from each new measurement in real-time. The data is acquired in motion, thus it provides multiple points of view. When processed, these multiple points of view are adaptively combined by taking into account the reliability of each individual measurement which can vary due to a variety of factors such as angle of incidence, distance between the device and the subject and environmental sensor data or other factors influencing a confidence of the thermal-infrared data when captured. Finally, several case studies are presented to support the usability and performance of the proposed system.

  18. 3D printed bionic ears.

    PubMed

    Mannoor, Manu S; Jiang, Ziwen; James, Teena; Kong, Yong Lin; Malatesta, Karen A; Soboyejo, Winston O; Verma, Naveen; Gracias, David H; McAlpine, Michael C

    2013-06-12

    The ability to three-dimensionally interweave biological tissue with functional electronics could enable the creation of bionic organs possessing enhanced functionalities over their human counterparts. Conventional electronic devices are inherently two-dimensional, preventing seamless multidimensional integration with synthetic biology, as the processes and materials are very different. Here, we present a novel strategy for overcoming these difficulties via additive manufacturing of biological cells with structural and nanoparticle derived electronic elements. As a proof of concept, we generated a bionic ear via 3D printing of a cell-seeded hydrogel matrix in the anatomic geometry of a human ear, along with an intertwined conducting polymer consisting of infused silver nanoparticles. This allowed for in vitro culturing of cartilage tissue around an inductive coil antenna in the ear, which subsequently enables readout of inductively-coupled signals from cochlea-shaped electrodes. The printed ear exhibits enhanced auditory sensing for radio frequency reception, and complementary left and right ears can listen to stereo audio music. Overall, our approach suggests a means to intricately merge biologic and nanoelectronic functionalities via 3D printing. PMID:23635097

  19. 3D Printable Graphene Composite

    PubMed Central

    Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong

    2015-01-01

    In human being’s history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today’s personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite’s linear thermal coefficient is below 75 ppm·°C−1 from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process. PMID:26153673

  20. 3D Printable Graphene Composite

    NASA Astrophysics Data System (ADS)

    Wei, Xiaojun; Li, Dong; Jiang, Wei; Gu, Zheming; Wang, Xiaojuan; Zhang, Zengxing; Sun, Zhengzong

    2015-07-01

    In human being’s history, both the Iron Age and Silicon Age thrived after a matured massive processing technology was developed. Graphene is the most recent superior material which could potentially initialize another new material Age. However, while being exploited to its full extent, conventional processing methods fail to provide a link to today’s personalization tide. New technology should be ushered in. Three-dimensional (3D) printing fills the missing linkage between graphene materials and the digital mainstream. Their alliance could generate additional stream to push the graphene revolution into a new phase. Here we demonstrate for the first time, a graphene composite, with a graphene loading up to 5.6 wt%, can be 3D printable into computer-designed models. The composite’s linear thermal coefficient is below 75 ppm·°C-1 from room temperature to its glass transition temperature (Tg), which is crucial to build minute thermal stress during the printing process.

  1. 3D Printing: 3D Printing of Conductive Complex Structures with In Situ Generation of Silver Nanoparticles (Adv. Mater. 19/2016).

    PubMed

    Fantino, Erika; Chiappone, Annalisa; Roppolo, Ignazio; Manfredi, Diego; Bongiovanni, Roberta; Pirri, Candido Fabrizio; Calignano, Flaviana

    2016-05-01

    On page 3712, E. Fantino, A. Chiappone, and co-workers fabricate conductive 3D hybrid structures by coupling the photo-reduction of metal precursors with 3D printing technology. The generated structures consist of metal nanoparticles embedded in a polymer matrix shaped into complex multilayered architectures. 3D conductive structures are fabricated with a digital light-processing printer incorporating silver salt into photocurable formulations. PMID:27167030

  2. 3D Printing: 3D Printing of Conductive Complex Structures with In Situ Generation of Silver Nanoparticles (Adv. Mater. 19/2016).

    PubMed

    Fantino, Erika; Chiappone, Annalisa; Roppolo, Ignazio; Manfredi, Diego; Bongiovanni, Roberta; Pirri, Candido Fabrizio; Calignano, Flaviana

    2016-05-01

    On page 3712, E. Fantino, A. Chiappone, and co-workers fabricate conductive 3D hybrid structures by coupling the photo-reduction of metal precursors with 3D printing technology. The generated structures consist of metal nanoparticles embedded in a polymer matrix shaped into complex multilayered architectures. 3D conductive structures are fabricated with a digital light-processing printer incorporating silver salt into photocurable formulations.

  3. LOTT RANCH 3D PROJECT

    SciTech Connect

    Larry Lawrence; Bruce Miller

    2004-09-01

    The Lott Ranch 3D seismic prospect located in Garza County, Texas is a project initiated in September of 1991 by the J.M. Huber Corp., a petroleum exploration and production company. By today's standards the 126 square mile project does not seem monumental, however at the time it was conceived it was the most intensive land 3D project ever attempted. Acquisition began in September of 1991 utilizing GEO-SEISMIC, INC., a seismic data contractor. The field parameters were selected by J.M. Huber, and were of a radical design. The recording instruments used were GeoCor IV amplifiers designed by Geosystems Inc., which record the data in signed bit format. It would not have been practical, if not impossible, to have processed the entire raw volume with the tools available at that time. The end result was a dataset that was thought to have little utility due to difficulties in processing the field data. In 1997, Yates Energy Corp. located in Roswell, New Mexico, formed a partnership to further develop the project. Through discussions and meetings with Pinnacle Seismic, it was determined that the original Lott Ranch 3D volume could be vastly improved upon reprocessing. Pinnacle Seismic had shown the viability of improving field-summed signed bit data on smaller 2D and 3D projects. Yates contracted Pinnacle Seismic Ltd. to perform the reprocessing. This project was initiated with high resolution being a priority. Much of the potential resolution was lost through the initial summing of the field data. Modern computers that are now being utilized have tremendous speed and storage capacities that were cost prohibitive when this data was initially processed. Software updates and capabilities offer a variety of quality control and statics resolution, which are pertinent to the Lott Ranch project. The reprocessing effort was very successful. The resulting processed data-set was then interpreted using modern PC-based interpretation and mapping software. Production data, log data

  4. Peptide Directed 3D Assembly of Nanoparticles through Biomolecular Interaction

    NASA Astrophysics Data System (ADS)

    Kaur, Prerna

    The current challenge of the 'bottom up' process is the programmed self-assembly of nanoscale building blocks into complex and larger-scale superstructures with unique properties that can be integrated as components in solar cells, microelectronics, meta materials, catalysis, and sensors. Recent trends in the complexity of device design demand the fabrication of three-dimensional (3D) superstructures from multi-nanomaterial components in precise configurations. Bio mimetic assembly is an emerging technique for building hybrid materials because living organisms are efficient, inexpensive, and environmentally benign material generators, allowing low temperature fabrication. Using this approach, a novel peptide-directed nanomaterial assembly technology based on bio molecular interaction of streptavidin and biotin is presented for assembling nanomaterials with peptides for the construction of 3D peptide-inorganic superlattices with defined 3D shape. We took advantage of robust natural collagen triple-helix peptides and used them as nanowire building blocks for 3D peptide-gold nanoparticles superlattice generation. The type of 3D peptide superlattice assembly with hybrid NP building blocks described herein shows potential for the fabrication of complex functional device which demands precise long-range arrangement and periodicity of NPs.

  5. 3D Printing of Graphene Aerogels.

    PubMed

    Zhang, Qiangqiang; Zhang, Feng; Medarametla, Sai Pradeep; Li, Hui; Zhou, Chi; Lin, Dong

    2016-04-01

    3D printing of a graphene aerogel with true 3D overhang structures is highlighted. The aerogel is fabricated by combining drop-on-demand 3D printing and freeze casting. The water-based GO ink is ejected and freeze-cast into designed 3D structures. The lightweight (<10 mg cm(-3) ) 3D printed graphene aerogel presents superelastic and high electrical conduction.

  6. 3D Printing of Graphene Aerogels.

    PubMed

    Zhang, Qiangqiang; Zhang, Feng; Medarametla, Sai Pradeep; Li, Hui; Zhou, Chi; Lin, Dong

    2016-04-01

    3D printing of a graphene aerogel with true 3D overhang structures is highlighted. The aerogel is fabricated by combining drop-on-demand 3D printing and freeze casting. The water-based GO ink is ejected and freeze-cast into designed 3D structures. The lightweight (<10 mg cm(-3) ) 3D printed graphene aerogel presents superelastic and high electrical conduction. PMID:26861680

  7. ShowMe3D

    SciTech Connect

    Sinclair, Michael B

    2012-01-05

    ShowMe3D is a data visualization graphical user interface specifically designed for use with hyperspectral image obtained from the Hyperspectral Confocal Microscope. The program allows the user to select and display any single image from a three dimensional hyperspectral image stack. By moving a slider control, the user can easily move between images of the stack. The user can zoom into any region of the image. The user can select any pixel or region from the displayed image and display the fluorescence spectrum associated with that pixel or region. The user can define up to 3 spectral filters to apply to the hyperspectral image and view the image as it would appear from a filter-based confocal microscope. The user can also obtain statistics such as intensity average and variance from selected regions.

  8. 3D Elastic Wavefield Tomography

    NASA Astrophysics Data System (ADS)

    Guasch, L.; Warner, M.; Stekl, I.; Umpleby, A.; Shah, N.

    2010-12-01

    Wavefield tomography, or waveform inversion, aims to extract the maximum information from seismic data by matching trace by trace the response of the solid earth to seismic waves using numerical modelling tools. Its first formulation dates from the early 80's, when Albert Tarantola developed a solid theoretical basis that is still used today with little change. Due to computational limitations, the application of the method to 3D problems has been unaffordable until a few years ago, and then only under the acoustic approximation. Although acoustic wavefield tomography is widely used, a complete solution of the seismic inversion problem requires that we account properly for the physics of wave propagation, and so must include elastic effects. We have developed a 3D tomographic wavefield inversion code that incorporates the full elastic wave equation. The bottle neck of the different implementations is the forward modelling algorithm that generates the synthetic data to be compared with the field seismograms as well as the backpropagation of the residuals needed to form the direction update of the model parameters. Furthermore, one or two extra modelling runs are needed in order to calculate the step-length. Our approach uses a FD scheme explicit time-stepping by finite differences that are 4th order in space and 2nd order in time, which is a 3D version of the one developed by Jean Virieux in 1986. We chose the time domain because an explicit time scheme is much less demanding in terms of memory than its frequency domain analogue, although the discussion of wich domain is more efficient still remains open. We calculate the parameter gradients for Vp and Vs by correlating the normal and shear stress wavefields respectively. A straightforward application would lead to the storage of the wavefield at all grid points at each time-step. We tackled this problem using two different approaches. The first one makes better use of resources for small models of dimension equal

  9. Conducting Polymer 3D Microelectrodes

    PubMed Central

    Sasso, Luigi; Vazquez, Patricia; Vedarethinam, Indumathi; Castillo-León, Jaime; Emnéus, Jenny; Svendsen, Winnie E.

    2010-01-01

    Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of micro-fabrication techniques and chemical polymerization methods has been used to create pillar electrodes in polyaniline and polypyrrole. The thin polymer films obtained showed uniformity and good adhesion to both horizontal and vertical surfaces. Electrodes in combination with metal/conducting polymer materials have been characterized by cyclic voltammetry and the presence of the conducting polymer film has shown to increase the electrochemical activity when compared with electrodes coated with only metal. An electrochemical characterization of gold/polypyrrole electrodes showed exceptional electrochemical behavior and activity. PC12 cells were finally cultured on the investigated materials as a preliminary biocompatibility assessment. These results show that the described electrodes are possibly suitable for future in-vitro neurological measurements. PMID:22163508

  10. ShowMe3D

    2012-01-05

    ShowMe3D is a data visualization graphical user interface specifically designed for use with hyperspectral image obtained from the Hyperspectral Confocal Microscope. The program allows the user to select and display any single image from a three dimensional hyperspectral image stack. By moving a slider control, the user can easily move between images of the stack. The user can zoom into any region of the image. The user can select any pixel or region from themore » displayed image and display the fluorescence spectrum associated with that pixel or region. The user can define up to 3 spectral filters to apply to the hyperspectral image and view the image as it would appear from a filter-based confocal microscope. The user can also obtain statistics such as intensity average and variance from selected regions.« less

  11. Supernova Remnant in 3-D

    NASA Technical Reports Server (NTRS)

    2009-01-01

    wavelengths. Since the amount of the wavelength shift is related to the speed of motion, one can determine how fast the debris are moving in either direction. Because Cas A is the result of an explosion, the stellar debris is expanding radially outwards from the explosion center. Using simple geometry, the scientists were able to construct a 3-D model using all of this information. A program called 3-D Slicer modified for astronomical use by the Astronomical Medicine Project at Harvard University in Cambridge, Mass. was used to display and manipulate the 3-D model. Commercial software was then used to create the 3-D fly-through.

    The blue filaments defining the blast wave were not mapped using the Doppler effect because they emit a different kind of light synchrotron radiation that does not emit light at discrete wavelengths, but rather in a broad continuum. The blue filaments are only a representation of the actual filaments observed at the blast wave.

    This visualization shows that there are two main components to this supernova remnant: a spherical component in the outer parts of the remnant and a flattened (disk-like) component in the inner region. The spherical component consists of the outer layer of the star that exploded, probably made of helium and carbon. These layers drove a spherical blast wave into the diffuse gas surrounding the star. The flattened component that astronomers were unable to map into 3-D prior to these Spitzer observations consists of the inner layers of the star. It is made from various heavier elements, not all shown in the visualization, such as oxygen, neon, silicon, sulphur, argon and iron.

    High-velocity plumes, or jets, of this material are shooting out from the explosion in the plane of the disk-like component mentioned above. Plumes of silicon appear in the northeast and southwest, while those of iron are seen in the southeast and north. These jets were already known and Doppler velocity measurements have been made for these

  12. 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.

  13. DSI3D-RCS: Theory manual

    SciTech Connect

    Madsen, N.; Steich, D.; Cook, G.; Eme, B.

    1995-03-16

    The DSI3D-RCS code is designed to numerically evaluate radar cross sections on complex objects by solving Maxwell`s curl equations in the time-domain and in three space dimensions. The code has been designed to run on the new parallel processing computers as well as on conventional serial computers. The DSI3D-RCS code is unique for the following reasons: Allows the use of unstructured non-orthogonal grids, allows a variety of cell or element types, reduces to be the Finite Difference Time Domain (FDTD) method when orthogonal grids are used, preserves charge or divergence locally (and globally), is conditionally stable, is non-dissipative, is accurate for non-orthogonal grids. This method is derived using a Discrete Surface Integration (DSI) technique. As formulated, the DSI technique can be used with essentially arbitrary unstructured grids composed of convex polyhedral cells. This implementation of the DSI algorithm allows the use of unstructured grids that are composed of combinations of non-orthogonal hexahedrons, tetrahedrons, triangular prisms and pyramids. This algorithm reduces to the conventional FDTD method when applied on a structured orthogonal hexahedral grid.

  14. Supernova Remnant in 3-D

    NASA Technical Reports Server (NTRS)

    2009-01-01

    wavelengths. Since the amount of the wavelength shift is related to the speed of motion, one can determine how fast the debris are moving in either direction. Because Cas A is the result of an explosion, the stellar debris is expanding radially outwards from the explosion center. Using simple geometry, the scientists were able to construct a 3-D model using all of this information. A program called 3-D Slicer modified for astronomical use by the Astronomical Medicine Project at Harvard University in Cambridge, Mass. was used to display and manipulate the 3-D model. Commercial software was then used to create the 3-D fly-through.

    The blue filaments defining the blast wave were not mapped using the Doppler effect because they emit a different kind of light synchrotron radiation that does not emit light at discrete wavelengths, but rather in a broad continuum. The blue filaments are only a representation of the actual filaments observed at the blast wave.

    This visualization shows that there are two main components to this supernova remnant: a spherical component in the outer parts of the remnant and a flattened (disk-like) component in the inner region. The spherical component consists of the outer layer of the star that exploded, probably made of helium and carbon. These layers drove a spherical blast wave into the diffuse gas surrounding the star. The flattened component that astronomers were unable to map into 3-D prior to these Spitzer observations consists of the inner layers of the star. It is made from various heavier elements, not all shown in the visualization, such as oxygen, neon, silicon, sulphur, argon and iron.

    High-velocity plumes, or jets, of this material are shooting out from the explosion in the plane of the disk-like component mentioned above. Plumes of silicon appear in the northeast and southwest, while those of iron are seen in the southeast and north. These jets were already known and Doppler velocity measurements have been made for these

  15. A Hybrid Monte Carlo-Deterministic Method for Global Binary Stochastic Medium Transport Problems

    SciTech Connect

    Keady, K P; Brantley, P

    2010-03-04

    Global deep-penetration transport problems are difficult to solve using traditional Monte Carlo techniques. In these problems, the scalar flux distribution is desired at all points in the spatial domain (global nature), and the scalar flux typically drops by several orders of magnitude across the problem (deep-penetration nature). As a result, few particle histories may reach certain regions of the domain, producing a relatively large variance in tallies in those regions. Implicit capture (also known as survival biasing or absorption suppression) can be used to increase the efficiency of the Monte Carlo transport algorithm to some degree. A hybrid Monte Carlo-deterministic technique has previously been developed by Cooper and Larsen to reduce variance in global problems by distributing particles more evenly throughout the spatial domain. This hybrid method uses an approximate deterministic estimate of the forward scalar flux distribution to automatically generate weight windows for the Monte Carlo transport simulation, avoiding the necessity for the code user to specify the weight window parameters. In a binary stochastic medium, the material properties at a given spatial location are known only statistically. The most common approach to solving particle transport problems involving binary stochastic media is to use the atomic mix (AM) approximation in which the transport problem is solved using ensemble-averaged material properties. The most ubiquitous deterministic model developed specifically for solving binary stochastic media transport problems is the Levermore-Pomraning (L-P) model. Zimmerman and Adams proposed a Monte Carlo algorithm (Algorithm A) that solves the Levermore-Pomraning equations and another Monte Carlo algorithm (Algorithm B) that is more accurate as a result of improved local material realization modeling. Recent benchmark studies have shown that Algorithm B is often significantly more accurate than Algorithm A (and therefore the L-P model

  16. A hybrid SVM-FFA method for prediction of monthly mean global solar radiation

    NASA Astrophysics Data System (ADS)

    Shamshirband, Shahaboddin; Mohammadi, Kasra; Tong, Chong Wen; Zamani, Mazdak; Motamedi, Shervin; Ch, Sudheer

    2016-07-01

    In this study, a hybrid support vector machine-firefly optimization algorithm (SVM-FFA) model is proposed to estimate monthly mean horizontal global solar radiation (HGSR). The merit of SVM-FFA is assessed statistically by comparing its performance with three previously used approaches. Using each approach and long-term measured HGSR, three models are calibrated by considering different sets of meteorological parameters measured for Bandar Abbass situated in Iran. It is found that the model (3) utilizing the combination of relative sunshine duration, difference between maximum and minimum temperatures, relative humidity, water vapor pressure, average temperature, and extraterrestrial solar radiation shows superior performance based upon all approaches. Moreover, the extraterrestrial radiation is introduced as a significant parameter to accurately estimate the global solar radiation. The survey results reveal that the developed SVM-FFA approach is greatly capable to provide favorable predictions with significantly higher precision than other examined techniques. For the SVM-FFA (3), the statistical indicators of mean absolute percentage error (MAPE), root mean square error (RMSE), relative root mean square error (RRMSE), and coefficient of determination ( R 2) are 3.3252 %, 0.1859 kWh/m2, 3.7350 %, and 0.9737, respectively which according to the RRMSE has an excellent performance. As a more evaluation of SVM-FFA (3), the ratio of estimated to measured values is computed and found that 47 out of 48 months considered as testing data fall between 0.90 and 1.10. Also, by performing a further verification, it is concluded that SVM-FFA (3) offers absolute superiority over the empirical models using relatively similar input parameters. In a nutshell, the hybrid SVM-FFA approach would be considered highly efficient to estimate the HGSR.

  17. 3D multiplexed immunoplasmonics microscopy

    NASA Astrophysics Data System (ADS)

    Bergeron, Éric; Patskovsky, Sergiy; Rioux, David; Meunier, Michel

    2016-07-01

    Selective labelling, identification and spatial distribution of cell surface biomarkers can provide important clinical information, such as distinction between healthy and diseased cells, evolution of a disease and selection of the optimal patient-specific treatment. Immunofluorescence is the gold standard for efficient detection of biomarkers expressed by cells. However, antibodies (Abs) conjugated to fluorescent dyes remain limited by their photobleaching, high sensitivity to the environment, low light intensity, and wide absorption and emission spectra. Immunoplasmonics is a novel microscopy method based on the visualization of Abs-functionalized plasmonic nanoparticles (fNPs) targeting cell surface biomarkers. Tunable fNPs should provide higher multiplexing capacity than immunofluorescence since NPs are photostable over time, strongly scatter light at their plasmon peak wavelengths and can be easily functionalized. In this article, we experimentally demonstrate accurate multiplexed detection based on the immunoplasmonics approach. First, we achieve the selective labelling of three targeted cell surface biomarkers (cluster of differentiation 44 (CD44), epidermal growth factor receptor (EGFR) and voltage-gated K+ channel subunit KV1.1) on human cancer CD44+ EGFR+ KV1.1+ MDA-MB-231 cells and reference CD44- EGFR- KV1.1+ 661W cells. The labelling efficiency with three stable specific immunoplasmonics labels (functionalized silver nanospheres (CD44-AgNSs), gold (Au) NSs (EGFR-AuNSs) and Au nanorods (KV1.1-AuNRs)) detected by reflected light microscopy (RLM) is similar to the one with immunofluorescence. Second, we introduce an improved method for 3D localization and spectral identification of fNPs based on fast z-scanning by RLM with three spectral filters corresponding to the plasmon peak wavelengths of the immunoplasmonics labels in the cellular environment (500 nm for 80 nm AgNSs, 580 nm for 100 nm AuNSs and 700 nm for 40 nm × 92 nm AuNRs). Third, the developed

  18. 3D multiplexed immunoplasmonics microscopy.

    PubMed

    Bergeron, Éric; Patskovsky, Sergiy; Rioux, David; Meunier, Michel

    2016-07-21

    Selective labelling, identification and spatial distribution of cell surface biomarkers can provide important clinical information, such as distinction between healthy and diseased cells, evolution of a disease and selection of the optimal patient-specific treatment. Immunofluorescence is the gold standard for efficient detection of biomarkers expressed by cells. However, antibodies (Abs) conjugated to fluorescent dyes remain limited by their photobleaching, high sensitivity to the environment, low light intensity, and wide absorption and emission spectra. Immunoplasmonics is a novel microscopy method based on the visualization of Abs-functionalized plasmonic nanoparticles (fNPs) targeting cell surface biomarkers. Tunable fNPs should provide higher multiplexing capacity than immunofluorescence since NPs are photostable over time, strongly scatter light at their plasmon peak wavelengths and can be easily functionalized. In this article, we experimentally demonstrate accurate multiplexed detection based on the immunoplasmonics approach. First, we achieve the selective labelling of three targeted cell surface biomarkers (cluster of differentiation 44 (CD44), epidermal growth factor receptor (EGFR) and voltage-gated K(+) channel subunit KV1.1) on human cancer CD44(+) EGFR(+) KV1.1(+) MDA-MB-231 cells and reference CD44(-) EGFR(-) KV1.1(+) 661W cells. The labelling efficiency with three stable specific immunoplasmonics labels (functionalized silver nanospheres (CD44-AgNSs), gold (Au) NSs (EGFR-AuNSs) and Au nanorods (KV1.1-AuNRs)) detected by reflected light microscopy (RLM) is similar to the one with immunofluorescence. Second, we introduce an improved method for 3D localization and spectral identification of fNPs based on fast z-scanning by RLM with three spectral filters corresponding to the plasmon peak wavelengths of the immunoplasmonics labels in the cellular environment (500 nm for 80 nm AgNSs, 580 nm for 100 nm AuNSs and 700 nm for 40 nm × 92 nm AuNRs). Third

  19. NIF Ignition Target 3D Point Design

    SciTech Connect

    Jones, O; Marinak, M; Milovich, J; Callahan, D

    2008-11-05

    We have developed an input file for running 3D NIF hohlraums that is optimized such that it can be run in 1-2 days on parallel computers. We have incorporated increasing levels of automation into the 3D input file: (1) Configuration controlled input files; (2) Common file for 2D and 3D, different types of capsules (symcap, etc.); and (3) Can obtain target dimensions, laser pulse, and diagnostics settings automatically from NIF Campaign Management Tool. Using 3D Hydra calculations to investigate different problems: (1) Intrinsic 3D asymmetry; (2) Tolerance to nonideal 3D effects (e.g. laser power balance, pointing errors); and (3) Synthetic diagnostics.

  20. 3D Kitaev spin liquids

    NASA Astrophysics Data System (ADS)

    Hermanns, Maria

    The Kitaev honeycomb model has become one of the archetypal spin models exhibiting topological phases of matter, where the magnetic moments fractionalize into Majorana fermions interacting with a Z2 gauge field. In this talk, we discuss generalizations of this model to three-dimensional lattice structures. Our main focus is the metallic state that the emergent Majorana fermions form. In particular, we discuss the relation of the nature of this Majorana metal to the details of the underlying lattice structure. Besides (almost) conventional metals with a Majorana Fermi surface, one also finds various realizations of Dirac semi-metals, where the gapless modes form Fermi lines or even Weyl nodes. We introduce a general classification of these gapless quantum spin liquids using projective symmetry analysis. Furthermore, we briefly outline why these Majorana metals in 3D Kitaev systems provide an even richer variety of Dirac and Weyl phases than possible for electronic matter and comment on possible experimental signatures. Work done in collaboration with Kevin O'Brien and Simon Trebst.

  1. Locomotive wheel 3D reconstruction

    NASA Astrophysics Data System (ADS)

    Guan, Xin; Luo, Zhisheng; Gao, Xiaorong; Wu, Jianle

    2010-08-01

    In the article, a system, which is used to reconstruct locomotive wheels, is described, helping workers detect the condition of a wheel through a direct view. The system consists of a line laser, a 2D camera, and a computer. We use 2D camera to capture the line-laser light reflected by the object, a wheel, and then compute the final coordinates of the structured light. Finally, using Matlab programming language, we transform the coordinate of points to a smooth surface and illustrate the 3D view of the wheel. The article also proposes the system structure, processing steps and methods, and sets up an experimental platform to verify the design proposal. We verify the feasibility of the whole process, and analyze the results comparing to standard date. The test results show that this system can work well, and has a high accuracy on the reconstruction. And because there is still no such application working in railway industries, so that it has practical value in railway inspection system.

  2. 3D multiplexed immunoplasmonics microscopy

    NASA Astrophysics Data System (ADS)

    Bergeron, Éric; Patskovsky, Sergiy; Rioux, David; Meunier, Michel

    2016-07-01

    Selective labelling, identification and spatial distribution of cell surface biomarkers can provide important clinical information, such as distinction between healthy and diseased cells, evolution of a disease and selection of the optimal patient-specific treatment. Immunofluorescence is the gold standard for efficient detection of biomarkers expressed by cells. However, antibodies (Abs) conjugated to fluorescent dyes remain limited by their photobleaching, high sensitivity to the environment, low light intensity, and wide absorption and emission spectra. Immunoplasmonics is a novel microscopy method based on the visualization of Abs-functionalized plasmonic nanoparticles (fNPs) targeting cell surface biomarkers. Tunable fNPs should provide higher multiplexing capacity than immunofluorescence since NPs are photostable over time, strongly scatter light at their plasmon peak wavelengths and can be easily functionalized. In this article, we experimentally demonstrate accurate multiplexed detection based on the immunoplasmonics approach. First, we achieve the selective labelling of three targeted cell surface biomarkers (cluster of differentiation 44 (CD44), epidermal growth factor receptor (EGFR) and voltage-gated K+ channel subunit KV1.1) on human cancer CD44+ EGFR+ KV1.1+ MDA-MB-231 cells and reference CD44- EGFR- KV1.1+ 661W cells. The labelling efficiency with three stable specific immunoplasmonics labels (functionalized silver nanospheres (CD44-AgNSs), gold (Au) NSs (EGFR-AuNSs) and Au nanorods (KV1.1-AuNRs)) detected by reflected light microscopy (RLM) is similar to the one with immunofluorescence. Second, we introduce an improved method for 3D localization and spectral identification of fNPs based on fast z-scanning by RLM with three spectral filters corresponding to the plasmon peak wavelengths of the immunoplasmonics labels in the cellular environment (500 nm for 80 nm AgNSs, 580 nm for 100 nm AuNSs and 700 nm for 40 nm × 92 nm AuNRs). Third, the developed

  3. 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.

  4. Characterization through global hybrid simulations of solar wind ions impacting the dayside of Mercury

    NASA Astrophysics Data System (ADS)

    Chanteur, Gérard M.; Modolo, Ronan; Hess, Sébastien; Leblanc, François; Richer, Emilie

    2014-05-01

    It has long been suspected since Mariner-10 observations that solar wind ions could reach the surface of Mercury: Kallio & Janhunen (2003) and Travnicek et al (2010) have presented simulated maps of precipitating proton fluxes. Attempts to refine estimations of precipitating fluxes of solar wind ions are important as these precipitations create additional sources of exospheric and possibly magnetospheric populations, and as their space-weathering effects modify the properties of the regolith. We run the global hybrid model used by Richer et al. (2012) which takes self-consistently into account the alpha particles of the solar wind to estimate fluxes of solar wind protons and alphas impacting the surface of Mercury under different IMF conditions. The internal source of the Hermean magnetic field is axisymmetric and is the superposition of a dipole and a quadrupole consistent with MESSENGER observations (Anderson et al., 2011) as in Richer et al. (2012). Results are briefly compared to predictions made with the offset dipole model of the planetary field. New simulations, made with an improved spatial resolution of 40km, reveal important differences between proton and alpha fluxes and show large variations with interplanetary conditions. In a first step we investigate the properties of solar wind ions impacting the dayside of the planet, precipitations on the night side will be examined later in a second step. References Anderson et al., Science, 333 , 1859, (2011) Kallio, E., and P. Janhunen, Solar wind and magnetospheric ion impact on Mercury's surface, Geophys. Res. Lett., 30(17), 1877, doi:10.1029/2003GL017842, 2003. Travnicek, P.M., D. Schriver, P. Hellinger, D. Hercik, B.J. Anderson, M. Sarantos, and J.A.Slavin, Mercury's magnetosphere-solar wind interaction for northward and southward interplanetary magnetic field: Hybrid simulation results, Icarus, doi:10.1016/j.icarus.2010.01.008, 2010 Richer, E., R. Modolo, G. M. Chanteur, S. Hess, and F. Leblanc (2012), A

  5. Global gene expression of Poncirus trifoliata, Citrus sunki and their hybrids under infection of Phytophthora parasitica

    PubMed Central

    2011-01-01

    Background Gummosis and root rot caused by Phytophthora are among the most economically important diseases in citrus. Four F1 resistant hybrids (Pool R), and four F1 susceptible hybrids (Pool S) to P. parasitica, were selected from a cross between susceptible Citrus sunki and resistant Poncirus trifoliata cv. Rubidoux. We investigated gene expression in pools of four resistant and four susceptible hybrids in comparison with their parents 48 hours after P. parasitica inoculation. We proposed that genes differentially expressed between resistant and susceptible parents and between their resistant and susceptible hybrids provide promising candidates for identifying transcripts involved in disease resistance. A microarray containing 62,876 UniGene transcripts selected from the CitEST database and prepared by NimbleGen Systems was used for analyzing global gene expression 48 hours after infection with P. parasitica. Results Three pairs of data comparisons (P. trifoliata/C. sunki, Pool R/C. sunki and Pool R/Pool S) were performed. With a filter of false-discovery rate less than 0.05 and fold change greater than 3.0, 21 UniGene transcripts common to the three pairwise comparative were found to be up-regulated, and 3 UniGene transcripts were down-regulated. Among them, our results indicated that the selected transcripts were probably involved in the whole process of plant defense responses to pathogen attack, including transcriptional regulation, signaling, activation of defense genes participating in HR, single dominant genes (R gene) such as TIR-NBS-LRR and RPS4 and switch of defense-related metabolism pathway. Differentially expressed genes were validated by RT-qPCR in susceptible and resistant plants and between inoculated and uninoculated control plants Conclusions Twenty four UniGene transcripts were identified as candidate genes for Citrus response to P. parasitica. UniGene transcripts were likely to be involved in disease resistance, such as genes potentially

  6. Filling gaps in cultural heritage documentation by 3D photography

    NASA Astrophysics Data System (ADS)

    Schuhr, W.; Lee, J. D.

    2015-08-01

    geometry" and to multistage concepts of 3D photographs in Cultural Heritage just started. Furthermore a revised list of the 3D visualization principles, claiming completeness, has been carried out. Beside others in an outlook *It is highly recommended, to list every historical and current stereo view with relevance to Cultural Heritage in a global Monument Information System (MIS), like in google earth. *3D photographs seem to be very suited, to complete and/or at least partly to replace manual archaeological sketches. In this concern the still underestimated 3D effect will be demonstrated, which even allows, e.g., the spatial perception of extremely small scratches etc... *A consequent dealing with 3D Technology even seems to indicate, currently we experience the beginning of a new age of "real 3DPC- screens", which at least could add or even partly replace the conventional 2D screens. Here the spatial visualization is verified without glasses in an all-around vitreous body. In this respect nowadays widespread lasered crystals showing monuments are identified as "Early Bird" 3D products, which, due to low resolution and contrast and due to lack of color, currently might even remember to the status of the invention of photography by Niepce (1827), but seem to promise a great future also in 3D Cultural Heritage documentation. *Last not least 3D printers more and more seem to conquer the IT-market, obviously showing an international competition.

  7. 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.

  8. Encapsulation and 3D culture of human adipose-derived stem cells in an in-situ crosslinked hybrid hydrogel composed of PEG-based hyperbranched copolymer and hyaluronic acid

    PubMed Central

    2013-01-01

    Introduction Cell therapy using adipose-derived stem cells has been reported to improve chronic wounds via differentiation and paracrine effects. One such strategy is to deliver stem cells in hydrogels, which are studied increasingly as cell delivery vehicles for therapeutic healing and inducing tissue regeneration. This study aimed to determine the behaviour of encapsulated adipose-derived stem cells and identify the secretion profile of suitable growth factors for wound healing in a newly developed thermoresponsive PEG–hyaluronic acid (HA) hybrid hydrogel to provide a novel living dressing system. Methods In this study, human adipose-derived stem cells (hADSCs) were encapsulated in situ in a water-soluble, thermoresponsive hyperbranched PEG-based copolymer (PEGMEMA–MEO2MA–PEGDA) with multiple acrylate functional groups in combination with thiolated HA, which was developed via deactivated enhanced atom transfer radical polymerisation of poly(ethylene glycol) methyl ether methacrylate (PEGMEMA, Mn = 475), 2-(2-methoxyethoxy) ethyl methacrylate (MEO2MA) and poly(ethylene glycol) diacrylate PEGDA (Mn = 258). hADSCs embedded in the PEGMEMA–MEO2MA–PEGDA and HA hybrid hydrogel system (P-SH-HA) were monitored and analysed for their cell viability, cell proliferation and secretion of growth factors (vascular endothelial growth factor, transforming growth factor beta and placental-derived growth factor) and cytokines (IFNγ, IL-2 and IL-10) under three-dimensional culture conditions via the ATP activity assay, alamarBlue® assay, LIVE/DEAD® assay and multiplex ELISA, respectively. Results hADSCs were successfully encapsulated in situ with high cell viability for up to 7 days in hydrogels. Although cellular proliferation was inhibited, cellular secretion of growth factors such as vascular endothelial growth factor and placental-derived growth factor production increased over 7 days, whereas IL-2 and IFNγ release were unaffected. Conclusion This study indicates

  9. Forward ramp in 3D

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Mars Pathfinder's forward rover ramp can be seen successfully unfurled in this image, taken in stereo by the Imager for Mars Pathfinder (IMP) on Sol 3. 3D glasses are necessary to identify surface detail. This ramp was not used for the deployment of the microrover Sojourner, which occurred at the end of Sol 2. When this image was taken, Sojourner was still latched to one of the lander's petals, waiting for the command sequence that would execute its descent off of the lander's petal.

    The image helped Pathfinder scientists determine whether to deploy the rover using the forward or backward ramps and the nature of the first rover traverse. The metallic object at the lower left of the image is the lander's low-gain antenna. The square at the end of the ramp is one of the spacecraft's magnetic targets. Dust that accumulates on the magnetic targets will later be examined by Sojourner's Alpha Proton X-Ray Spectrometer instrument for chemical analysis. At right, a lander petal is visible.

    The IMP is a stereo imaging system with color capability provided by 24 selectable filters -- twelve filters per 'eye.' It stands 1.8 meters above the Martian surface, and has a resolution of two millimeters at a range of two meters.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

    Click below to see the left and right views individually. [figure removed for brevity, see original site] Left [figure removed for brevity, see original site] Right

  10. 3D grain boundary migration

    NASA Astrophysics Data System (ADS)

    Becker, J. K.; Bons, P. D.

    2009-04-01

    Microstructures of rocks play an important role in determining rheological properties and help to reveal the processes that lead to their formation. Some of these processes change the microstructure significantly and may thus have the opposite effect in obliterating any fabrics indicative of the previous history of the rocks. One of these processes is grain boundary migration (GBM). During static recrystallisation, GBM may produce a foam texture that completely overprints a pre-existing grain boundary network and GBM actively influences the rheology of a rock, via its influence on grain size and lattice defect concentration. We here present a new numerical simulation software that is capable of simulating a whole range of processes on the grain scale (it is not limited to grain boundary migration). The software is polyhedron-based, meaning that each grain (or phase) is represented by a polyhedron that has discrete boundaries. The boundary (the shell) of the polyhedron is defined by a set of facets which in turn is defined by a set of vertices. Each structural entity (polyhedron, facets and vertices) can have an unlimited number of parameters (depending on the process to be modeled) such as surface energy, concentration, etc. which can be used to calculate changes of the microstructre. We use the processes of grain boundary migration of a "regular" and a partially molten rock to demonstrate the software. Since this software is 3D, the formation of melt networks in a partially molten rock can also be studied. The interconnected melt network is of fundamental importance for melt segregation and migration in the crust and mantle and can help to understand the core-mantle differentiation of large terrestrial planets.

  11. 3D affine registration using teaching-learning based optimization

    NASA Astrophysics Data System (ADS)

    Jani, Ashish; Savsani, Vimal; Pandya, Abhijit

    2013-09-01

    3D image registration is an emerging research field in the study of computer vision. In this paper, two effective global optimization methods are considered for the 3D registration of point clouds. Experiments were conducted by applying each algorithm and their performance was evaluated with respect to rigidity, similarity and affine transformations. Comparison of algorithms and its effectiveness was tested for the average performance to find the global solution for minimizing the error in the terms of distance between the model cloud and the data cloud. The parameters for the transformation matrix were considered as the design variables. Further comparisons of the considered methods were done for the computational effort, computational time and the convergence of the algorithm. The results reveal that the use of TLBO was outstanding for image processing application involving 3D registration. [Figure not available: see fulltext.

  12. 3-D Hybrid Kinetic Modeling of the Interaction Between the Solar Wind and Lunar-like Exospheric Pickup Ions in Case of Oblique/ Quasi-Parallel/Parallel Upstream Magnetic Field

    NASA Technical Reports Server (NTRS)

    Lipatov, A. S.; Farrell, W. M.; Cooper, J. F.; Sittler, E. C., Jr.; Hartle, R. E.

    2015-01-01

    The interactions between the solar wind and Moon-sized objects are determined by a set of the solar wind parameters and plasma environment of the space objects. The orientation of upstream magnetic field is one of the key factors which determines the formation and structure of bow shock wave/Mach cone or Alfven wing near the obstacle. The study of effects of the direction of the upstream magnetic field on lunar-like plasma environment is the main subject of our investigation in this paper. Photoionization, electron-impact ionization and charge exchange are included in our hybrid model. The computational model includes the self-consistent dynamics of the light (hydrogen (+), helium (+)) and heavy (sodium (+)) pickup ions. The lunar interior is considered as a weakly conducting body. Our previous 2013 lunar work, as reported in this journal, found formation of a triple structure of the Mach cone near the Moon in the case of perpendicular upstream magnetic field. Further advances in modeling now reveal the presence of strong wave activity in the upstream solar wind and plasma wake in the cases of quasiparallel and parallel upstream magnetic fields. However, little wave activity is found for the opposite case with a perpendicular upstream magnetic field. The modeling does not show a formation of the Mach cone in the case of theta(Sub B,U) approximately equal to 0 degrees.

  13. Designing 3D Multihierarchical Heteronanostructures for High-Performance On-Chip Hybrid Supercapacitors: Poly(3,4-(ethylenedioxy)thiophene)-Coated Diamond/Silicon Nanowire Electrodes in an Aprotic Ionic Liquid.

    PubMed

    Aradilla, David; Gao, Fang; Lewes-Malandrakis, Georgia; Müller-Sebert, Wolfgang; Gentile, Pascal; Boniface, Maxime; Aldakov, Dmitry; Iliev, Boyan; Schubert, Thomas J S; Nebel, Christoph E; Bidan, Gérard

    2016-07-20

    A versatile and robust hierarchically multifunctionalized nanostructured material made of poly(3,4-(ethylenedioxy)thiophene) (PEDOT)-coated diamond@silicon nanowires has been demonstrated to be an excellent capacitive electrode for supercapacitor devices. Thus, the electrochemical deposition of nanometric PEDOT films on diamond-coated silicon nanowire (SiNW) electrodes using N-methyl-N-propylpyrrolidinium bis((trifluoromethyl)sulfonyl)imide ionic liquid displayed a specific capacitance value of 140 F g(-1) at a scan rate of 1 mV s(-1). The as-grown functionalized electrodes were evaluated in a symmetric planar microsupercapacitor using butyltrimethylammonium bis((trifluoromethyl)sulfonyl)imide aprotic ionic liquid as the electrolyte. The device exhibited extraordinary energy and power density values of 26 mJ cm(-2) and 1.3 mW cm(-2) within a large voltage cell of 2.5 V, respectively. In addition, the system was able to retain 80% of its initial capacitance after 15 000 galvanostatic charge-discharge cycles at a high current density of 1 mA cm(-2) while maintaining a Coulombic efficiency around 100%. Therefore, this multifunctionalized hybrid device represents one of the best electrochemical performances concerning coated SiNW electrodes for a high-energy advanced on-chip supercapacitor. PMID:27348192

  14. Designing 3D Multihierarchical Heteronanostructures for High-Performance On-Chip Hybrid Supercapacitors: Poly(3,4-(ethylenedioxy)thiophene)-Coated Diamond/Silicon Nanowire Electrodes in an Aprotic Ionic Liquid.

    PubMed

    Aradilla, David; Gao, Fang; Lewes-Malandrakis, Georgia; Müller-Sebert, Wolfgang; Gentile, Pascal; Boniface, Maxime; Aldakov, Dmitry; Iliev, Boyan; Schubert, Thomas J S; Nebel, Christoph E; Bidan, Gérard

    2016-07-20

    A versatile and robust hierarchically multifunctionalized nanostructured material made of poly(3,4-(ethylenedioxy)thiophene) (PEDOT)-coated diamond@silicon nanowires has been demonstrated to be an excellent capacitive electrode for supercapacitor devices. Thus, the electrochemical deposition of nanometric PEDOT films on diamond-coated silicon nanowire (SiNW) electrodes using N-methyl-N-propylpyrrolidinium bis((trifluoromethyl)sulfonyl)imide ionic liquid displayed a specific capacitance value of 140 F g(-1) at a scan rate of 1 mV s(-1). The as-grown functionalized electrodes were evaluated in a symmetric planar microsupercapacitor using butyltrimethylammonium bis((trifluoromethyl)sulfonyl)imide aprotic ionic liquid as the electrolyte. The device exhibited extraordinary energy and power density values of 26 mJ cm(-2) and 1.3 mW cm(-2) within a large voltage cell of 2.5 V, respectively. In addition, the system was able to retain 80% of its initial capacitance after 15 000 galvanostatic charge-discharge cycles at a high current density of 1 mA cm(-2) while maintaining a Coulombic efficiency around 100%. Therefore, this multifunctionalized hybrid device represents one of the best electrochemical performances concerning coated SiNW electrodes for a high-energy advanced on-chip supercapacitor.

  15. 3-D Experimental Fracture Analysis at High Temperature

    SciTech Connect

    John H. Jackson; Albert S. Kobayashi

    2001-09-14

    T*e, which is an elastic-plastic fracture parameter based on incremental theory of plasticity, was determined numerically and experimentally. The T*e integral of a tunneling crack in 2024-T3 aluminum, three point bend specimen was obtained through a hybrid analysis of moire interferometry and 3-D elastic-plastic finite element analysis. The results were verified by the good agreement between the experimentally and numerically determined T*e on the specimen surface.

  16. 3D Printing and Its Urologic Applications

    PubMed Central

    Soliman, Youssef; Feibus, Allison H; Baum, Neil

    2015-01-01

    3D printing is the development of 3D objects via an additive process in which successive layers of material are applied under computer control. This article discusses 3D printing, with an emphasis on its historical context and its potential use in the field of urology. PMID:26028997

  17. Imaging a Sustainable Future in 3D

    NASA Astrophysics Data System (ADS)

    Schuhr, W.; Lee, J. D.; Kanngieser, E.

    2012-07-01

    It is the intention of this paper, to contribute to a sustainable future by providing objective object information based on 3D photography as well as promoting 3D photography not only for scientists, but also for amateurs. Due to the presentation of this article by CIPA Task Group 3 on "3D Photographs in Cultural Heritage", the presented samples are masterpieces of historic as well as of current 3D photography concentrating on cultural heritage. In addition to a report on exemplarily access to international archives of 3D photographs, samples for new 3D photographs taken with modern 3D cameras, as well as by means of a ground based high resolution XLITE staff camera and also 3D photographs taken from a captive balloon and the use of civil drone platforms are dealt with. To advise on optimum suited 3D methodology, as well as to catch new trends in 3D, an updated synoptic overview of the 3D visualization technology, even claiming completeness, has been carried out as a result of a systematic survey. In this respect, e.g., today's lasered crystals might be "early bird" products in 3D, which, due to lack in resolution, contrast and color, remember to the stage of the invention of photography.

  18. 3D Printing and Its Urologic Applications.

    PubMed

    Soliman, Youssef; Feibus, Allison H; Baum, Neil

    2015-01-01

    3D printing is the development of 3D objects via an additive process in which successive layers of material are applied under computer control. This article discusses 3D printing, with an emphasis on its historical context and its potential use in the field of urology.

  19. Beowulf 3D: a case study

    NASA Astrophysics Data System (ADS)

    Engle, Rob

    2008-02-01

    This paper discusses the creative and technical challenges encountered during the production of "Beowulf 3D," director Robert Zemeckis' adaptation of the Old English epic poem and the first film to be simultaneously released in IMAX 3D and digital 3D formats.

  20. Teaching Geography with 3-D Visualization Technology

    ERIC Educational Resources Information Center

    Anthamatten, Peter; Ziegler, Susy S.

    2006-01-01

    Technology that helps students view images in three dimensions (3-D) can support a broad range of learning styles. "Geo-Wall systems" are visualization tools that allow scientists, teachers, and students to project stereographic images and view them in 3-D. We developed and presented 3-D visualization exercises in several undergraduate courses.…

  1. Expanding Geometry Understanding with 3D Printing

    ERIC Educational Resources Information Center

    Cochran, Jill A.; Cochran, Zane; Laney, Kendra; Dean, Mandi

    2016-01-01

    With the rise of personal desktop 3D printing, a wide spectrum of educational opportunities has become available for educators to leverage this technology in their classrooms. Until recently, the ability to create physical 3D models was well beyond the scope, skill, and budget of many schools. However, since desktop 3D printers have become readily…

  2. 3D Elastic Seismic Wave Propagation Code

    1998-09-23

    E3D is capable of simulating seismic wave propagation in a 3D heterogeneous earth. Seismic waves are initiated by earthquake, explosive, and/or other sources. These waves propagate through a 3D geologic model, and are simulated as synthetic seismograms or other graphical output.

  3. 3D Flow Visualization Using Texture Advection

    NASA Technical Reports Server (NTRS)

    Kao, David; Zhang, Bing; Kim, Kwansik; Pang, Alex; Moran, Pat (Technical Monitor)

    2001-01-01

    Texture advection is an effective tool for animating and investigating 2D flows. In this paper, we discuss how this technique can be extended to 3D flows. In particular, we examine the use of 3D and 4D textures on 3D synthetic and computational fluid dynamics flow fields.

  4. 3D-stacked Ag nanowires for efficient plasmonic light absorbers and SERS sensors

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Ho; Mun, ChaeWon; Lee, MinKyoung; Park, Sung-Gyu

    2016-04-01

    We report new 3D hybrid plasmonic nanostructures exhibiting highly sensitive SERS-based sensing performance, utilizing efficient plasmonic light absorption and analyte-enrichment effect. The hybrid plasmonic nanostructures composed of 3D-stacked Ag NWs and NPs separated by a thin hydrophobic dielectric interlayer. A hydrophobic polydimethylsiloxane (PDMS) interlayer provides dielectric nanogap between Ag NWs and NPs, and analyte-enrichment effect due to the inhibition of drop spreading. The 3D hybrid PDMS-interlayered Ag nanostructures showed hydrophobicity with initial contact angle of 137.6°. Utilizing the analyte-enrichment strategy, the PDMS-interlayered Ag nanostructures exhibited an enhanced sensitivity of methylene blue molecules by a factor of 10 (limit of detection, LOD of 1.5 nM), compared to the alumina-separated 3D hybrid Ag nanostructures.

  5. Integration of real-time 3D capture, reconstruction, and light-field display

    NASA Astrophysics Data System (ADS)

    Zhang, Zhaoxing; Geng, Zheng; Li, Tuotuo; Pei, Renjing; Liu, Yongchun; Zhang, Xiao

    2015-03-01

    Effective integration of 3D acquisition, reconstruction (modeling) and display technologies into a seamless systems provides augmented experience of visualizing and analyzing real objects and scenes with realistic 3D sensation. Applications can be found in medical imaging, gaming, virtual or augmented reality and hybrid simulations. Although 3D acquisition, reconstruction, and display technologies have gained significant momentum in recent years, there seems a lack of attention on synergistically combining these components into a "end-to-end" 3D visualization system. We designed, built and tested an integrated 3D visualization system that is able to capture in real-time 3D light-field images, perform 3D reconstruction to build 3D model of the objects, and display the 3D model on a large autostereoscopic screen. In this article, we will present our system architecture and component designs, hardware/software implementations, and experimental results. We will elaborate on our recent progress on sparse camera array light-field 3D acquisition, real-time dense 3D reconstruction, and autostereoscopic multi-view 3D display. A prototype is finally presented with test results to illustrate the effectiveness of our proposed integrated 3D visualization system.

  6. 3D Printing of Conductive Complex Structures with In Situ Generation of Silver Nanoparticles.

    PubMed

    Fantino, Erika; Chiappone, Annalisa; Roppolo, Ignazio; Manfredi, Diego; Bongiovanni, Roberta; Pirri, Candido Fabrizio; Calignano, Flaviana

    2016-05-01

    Coupling the photoreduction of a metal precursor with 3D-printing technology is shown to allow the fabrication of conductive 3D hybrid structures consisting of metal nanoparticles and organic polymers shaped in complex multilayered architectures. 3D conductive structures are fabricated incorporating silver nitrate into a photocurable oligomer in the presence of suitable photoinitiators and exposing them to a digital light system. PMID:26992060

  7. 3-D Perspective Pasadena, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This perspective view shows the western part of the city of Pasadena, California, looking north towards the San Gabriel Mountains. Portions of the cities of Altadena and La Canada, Flintridge are also shown. The image was created from three datasets: the Shuttle Radar Topography Mission (SRTM) supplied the elevation data; Landsat data from November 11, 1986 provided the land surface color (not the sky) and U.S. Geological Survey digital aerial photography provides the image detail. The Rose Bowl, surrounded by a golf course, is the circular feature at the bottom center of the image. The Jet Propulsion Laboratory is the cluster of large buildings north of the Rose Bowl at the base of the mountains. A large landfill, Scholl Canyon, is the smooth area in the lower left corner of the scene. This image shows the power of combining data from different sources to create planning tools to study problems that affect large urban areas. In addition to the well-known earthquake hazards, Southern California is affected by a natural cycle of fire and mudflows. Wildfires strip the mountains of vegetation, increasing the hazards from flooding and mudflows for several years afterwards. Data such as shown on this image can be used to predict both how wildfires will spread over the terrain and also how mudflows will be channeled down the canyons. The Shuttle Radar Topography Mission (SRTM), launched on February 11, 2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission was designed to collect three dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency

  8. MOSSFRAC: An anisotropic 3D fracture model

    SciTech Connect

    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.

  9. Case study: Beauty and the Beast 3D: benefits of 3D viewing for 2D to 3D conversion

    NASA Astrophysics Data System (ADS)

    Handy Turner, Tara

    2010-02-01

    From the earliest stages of the Beauty and the Beast 3D conversion project, the advantages of accurate desk-side 3D viewing was evident. While designing and testing the 2D to 3D conversion process, the engineering team at Walt Disney Animation Studios proposed a 3D viewing configuration that not only allowed artists to "compose" stereoscopic 3D but also improved efficiency by allowing artists to instantly detect which image features were essential to the stereoscopic appeal of a shot and which features had minimal or even negative impact. At a time when few commercial 3D monitors were available and few software packages provided 3D desk-side output, the team designed their own prototype devices and collaborated with vendors to create a "3D composing" workstation. This paper outlines the display technologies explored, final choices made for Beauty and the Beast 3D, wish-lists for future development and a few rules of thumb for composing compelling 2D to 3D conversions.

  10. RELAP5-3D User Problems

    SciTech Connect

    Riemke, Richard Allan

    2002-09-01

    The Reactor Excursion and Leak Analysis Program with 3D capability1 (RELAP5-3D) is a reactor system analysis code that has been developed at the Idaho National Engineering and Environmental Laboratory (INEEL) for the U. S. Department of Energy (DOE). The 3D capability in RELAP5-3D includes 3D hydrodynamics2 and 3D neutron kinetics3,4. Assessment, verification, and validation of the 3D capability in RELAP5-3D is discussed in the literature5,6,7,8,9,10. Additional assessment, verification, and validation of the 3D capability of RELAP5-3D will be presented in other papers in this users seminar. As with any software, user problems occur. User problems usually fall into the categories of input processing failure, code execution failure, restart/renodalization failure, unphysical result, and installation. This presentation will discuss some of the more generic user problems that have been reported on RELAP5-3D as well as their resolution.

  11. 3D laptop for defense applications

    NASA Astrophysics Data System (ADS)

    Edmondson, Richard; Chenault, David

    2012-06-01

    Polaris Sensor Technologies has developed numerous 3D display systems using a US Army patented approach. These displays have been developed as prototypes for handheld controllers for robotic systems and closed hatch driving, and as part of a TALON robot upgrade for 3D vision, providing depth perception for the operator for improved manipulation and hazard avoidance. In this paper we discuss the prototype rugged 3D laptop computer and its applications to defense missions. The prototype 3D laptop combines full temporal and spatial resolution display with the rugged Amrel laptop computer. The display is viewed through protective passive polarized eyewear, and allows combined 2D and 3D content. Uses include robot tele-operation with live 3D video or synthetically rendered scenery, mission planning and rehearsal, enhanced 3D data interpretation, and simulation.

  12. The Feasibility of 3d Point Cloud Generation from Smartphones

    NASA Astrophysics Data System (ADS)

    Alsubaie, N.; El-Sheimy, N.

    2016-06-01

    This paper proposes a new technique for increasing the accuracy of direct geo-referenced image-based 3D point cloud generated from low-cost sensors in smartphones. The smartphone's motion sensors are used to directly acquire the Exterior Orientation Parameters (EOPs) of the captured images. These EOPs, along with the Interior Orientation Parameters (IOPs) of the camera/ phone, are used to reconstruct the image-based 3D point cloud. However, because smartphone motion sensors suffer from poor GPS accuracy, accumulated drift and high signal noise, inaccurate 3D mapping solutions often result. Therefore, horizontal and vertical linear features, visible in each image, are extracted and used as constraints in the bundle adjustment procedure. These constraints correct the relative position and orientation of the 3D mapping solution. Once the enhanced EOPs are estimated, the semi-global matching algorithm (SGM) is used to generate the image-based dense 3D point cloud. Statistical analysis and assessment are implemented herein, in order to demonstrate the feasibility of 3D point cloud generation from the consumer-grade sensors in smartphones.

  13. 3D laser imaging for concealed object identification

    NASA Astrophysics Data System (ADS)

    Berechet, Ion; Berginc, Gérard; Berechet, Stefan

    2014-09-01

    This paper deals with new optical non-conventional 3D laser imaging. Optical non-conventional imaging explores the advantages of laser imaging to form a three-dimensional image of the scene. 3D laser imaging can be used for threedimensional medical imaging, topography, surveillance, robotic vision because of ability to detect and recognize objects. In this paper, we present a 3D laser imaging for concealed object identification. The objective of this new 3D laser imaging is to provide the user a complete 3D reconstruction of the concealed object from available 2D data limited in number and with low representativeness. The 2D laser data used in this paper come from simulations that are based on the calculation of the laser interactions with the different interfaces of the scene of interest and from experimental results. We show the global 3D reconstruction procedures capable to separate objects from foliage and reconstruct a threedimensional image of the considered object. In this paper, we present examples of reconstruction and completion of three-dimensional images and we analyse the different parameters of the identification process such as resolution, the scenario of camouflage, noise impact and lacunarity degree.

  14. Imaging and 3D morphological analysis of collagen fibrils.

    PubMed

    Altendorf, H; Decencière, E; Jeulin, D; De sa Peixoto, P; Deniset-Besseau, A; Angelini, E; Mosser, G; Schanne-Klein, M-C

    2012-08-01

    The recent booming of multiphoton imaging of collagen fibrils by means of second harmonic generation microscopy generates the need for the development and automation of quantitative methods for image analysis. Standard approaches sequentially analyse two-dimensional (2D) slices to gain knowledge on the spatial arrangement and dimension of the fibrils, whereas the reconstructed three-dimensional (3D) image yields better information about these characteristics. In this work, a 3D analysis method is proposed for second harmonic generation images of collagen fibrils, based on a recently developed 3D fibre quantification method. This analysis uses operators from mathematical morphology. The fibril structure is scanned with a directional distance transform. Inertia moments of the directional distances yield the main fibre orientation, corresponding to the main inertia axis. The collaboration of directional distances and fibre orientation delivers a geometrical estimate of the fibre radius. The results include local maps as well as global distribution of orientation and radius of the fibrils over the 3D image. They also bring a segmentation of the image into foreground and background, as well as a classification of the foreground pixels into the preferred orientations. This accurate determination of the spatial arrangement of the fibrils within a 3D data set will be most relevant in biomedical applications. It brings the possibility to monitor remodelling of collagen tissues upon a variety of injuries and to guide tissues engineering because biomimetic 3D organizations and density are requested for better integration of implants.

  15. Dark matter in 3D

    DOE PAGES

    Alves, Daniele S. M.; El Hedri, Sonia; Wacker, Jay G.

    2016-03-21

    We discuss the relevance of directional detection experiments in the post-discovery era and propose a method to extract the local dark matter phase space distribution from directional data. The first feature of this method is a parameterization of the dark matter distribution function in terms of integrals of motion, which can be analytically extended to infer properties of the global distribution if certain equilibrium conditions hold. The second feature of our method is a decomposition of the distribution function in moments of a model independent basis, with minimal reliance on the ansatz for its functional form. We illustrate our methodmore » using the Via Lactea II N-body simulation as well as an analytical model for the dark matter halo. Furthermore, we conclude that O(1000) events are necessary to measure deviations from the Standard Halo Model and constrain or measure the presence of anisotropies.« less

  16. Dark Matter in 3D

    SciTech Connect

    Alves, Daniele S.M.; Hedri, Sonia El; Wacker, Jay G.

    2012-04-01

    We discuss the relevance of directional detection experiments in the post-discovery era and propose a method to extract the local dark matter phase space distribution from directional data. The first feature of this method is a parameterization of the dark matter distribution function in terms of integrals of motion, which can be analytically extended to infer properties of the global distribution if certain equilibrium conditions hold. The second feature of our method is a decomposition of the distribution function in moments of a model independent basis, with minimal reliance on the ansatz for its functional form. We illustrate our method using the Via Lactea II N-body simulation as well as an analytical model for the dark matter halo. We conclude that O(1000) events are necessary to measure deviations from the Standard Halo Model and constrain or measure the presence of anisotropies.

  17. Alignment-independent technique for 3D QSAR analysis.

    PubMed

    Wilkes, Jon G; Stoyanova-Slavova, Iva B; Buzatu, Dan A

    2016-04-01

    Molecular biochemistry is controlled by 3D phenomena but structure-activity models based on 3D descriptors are infrequently used for large data sets because of the computational overhead for determining molecular conformations. A diverse dataset of 146 androgen receptor binders was used to investigate how different methods for defining molecular conformations affect the performance of 3D-quantitative spectral data activity relationship models. Molecular conformations tested: (1) global minimum of molecules' potential energy surface; (2) alignment-to-templates using equal electronic and steric force field contributions; (3) alignment using contributions "Best-for-Each" template; (4) non-energy optimized, non-aligned (2D > 3D). Aggregate predictions from models were compared. Highest average coefficients of determination ranged from R Test (2) = 0.56 to 0.61. The best model using 2D > 3D (imported directly from ChemSpider) produced R Test (2) = 0.61. It was superior to energy-minimized and conformation-aligned models and was achieved in only 3-7 % of the time required using the other conformation strategies. Predictions averaged from models built on different conformations achieved a consensus R Test (2) = 0.65. The best 2D > 3D model was analyzed for underlying structure-activity relationships. For the compound strongest binding to the androgen receptor, 10 substructural features contributing to binding were flagged. Utility of 2D > 3D was compared for two other activity endpoints, each modeling a medium sized data set. Results suggested that large scale, accurate predictions using 2D > 3D SDAR descriptors may be produced for interactions involving endocrine system nuclear receptors and other data sets in which strongest activities are produced by fairly inflexible substrates.

  18. The agreement between 3D, standard 2D and triplane 2D speckle tracking: effects of image quality and 3D volume rate

    PubMed Central

    Stöbe, Stephan; Tarr, Adrienn; Pfeiffer, Dietrich; Hagendorff, Andreas

    2014-01-01

    Comparison of 3D and 2D speckle tracking performed on standard 2D and triplane 2D datasets of normal and pathological left ventricular (LV) wall-motion patterns with a focus on the effect that 3D volume rate (3DVR), image quality and tracking artifacts have on the agreement between 2D and 3D speckle tracking. 37 patients with normal LV function and 18 patients with ischaemic wall-motion abnormalities underwent 2D and 3D echocardiography, followed by offline speckle tracking measurements. The values of 3D global, regional and segmental strain were compared with the standard 2D and triplane 2D strain values. Correlation analysis with the LV ejection fraction (LVEF) was also performed. The 3D and 2D global strain values correlated good in both normally and abnormally contracting hearts, though systematic differences between the two methods were observed. Of the 3D strain parameters, the area strain showed the best correlation with the LVEF. The numerical agreement of 3D and 2D analyses varied significantly with the volume rate and image quality of the 3D datasets. The highest correlation between 2D and 3D peak systolic strain values was found between 3D area and standard 2D longitudinal strain. Regional wall-motion abnormalities were similarly detected by 2D and 3D speckle tracking. 2DST of triplane datasets showed similar results to those of conventional 2D datasets. 2D and 3D speckle tracking similarly detect normal and pathological wall-motion patterns. Limited image quality has a significant impact on the agreement between 3D and 2D numerical strain values. PMID:26693303

  19. 3-D Technology Approaches for Biological Ecologies

    NASA Astrophysics Data System (ADS)

    Liu, Liyu; Austin, Robert; U. S-China Physical-Oncology Sciences Alliance (PS-OA) Team

    Constructing three dimensional (3-D) landscapes is an inevitable issue in deep study of biological ecologies, because in whatever scales in nature, all of the ecosystems are composed by complex 3-D environments and biological behaviors. Just imagine if a 3-D technology could help complex ecosystems be built easily and mimic in vivo microenvironment realistically with flexible environmental controls, it will be a fantastic and powerful thrust to assist researchers for explorations. For years, we have been utilizing and developing different technologies for constructing 3-D micro landscapes for biophysics studies in in vitro. Here, I will review our past efforts, including probing cancer cell invasiveness with 3-D silicon based Tepuis, constructing 3-D microenvironment for cell invasion and metastasis through polydimethylsiloxane (PDMS) soft lithography, as well as explorations of optimized stenting positions for coronary bifurcation disease with 3-D wax printing and the latest home designed 3-D bio-printer. Although 3-D technologies is currently considered not mature enough for arbitrary 3-D micro-ecological models with easy design and fabrication, I hope through my talk, the audiences will be able to sense its significance and predictable breakthroughs in the near future. This work was supported by the State Key Development Program for Basic Research of China (Grant No. 2013CB837200), the National Natural Science Foundation of China (Grant No. 11474345) and the Beijing Natural Science Foundation (Grant No. 7154221).

  20. Automatic 3D video format detection

    NASA Astrophysics Data System (ADS)

    Zhang, Tao; Wang, Zhe; Zhai, Jiefu; Doyen, Didier

    2011-03-01

    Many 3D formats exist and will probably co-exist for a long time even if 3D standards are today under definition. The support for multiple 3D formats will be important for bringing 3D into home. In this paper, we propose a novel and effective method to detect whether a video is a 3D video or not, and to further identify the exact 3D format. First, we present how to detect those 3D formats that encode a pair of stereo images into a single image. The proposed method detects features and establishes correspondences between features in the left and right view images, and applies the statistics from the distribution of the positional differences between corresponding features to detect the existence of a 3D format and to identify the format. Second, we present how to detect the frame sequential 3D format. In the frame sequential 3D format, the feature points are oscillating from frame to frame. Similarly, the proposed method tracks feature points over consecutive frames, computes the positional differences between features, and makes a detection decision based on whether the features are oscillating. Experiments show the effectiveness of our method.

  1. RT3D tutorials for GMS users

    SciTech Connect

    Clement, T.P.; Jones, N.L.

    1998-02-01

    RT3D (Reactive Transport in 3-Dimensions) is a computer code that solves coupled partial differential equations that describe reactive-flow and transport of multiple mobile and/or immobile species in a three dimensional saturated porous media. RT3D was developed from the single-species transport code, MT3D (DoD-1.5, 1997 version). As with MT3D, RT3D also uses the USGS groundwater flow model MODFLOW for computing spatial and temporal variations in groundwater head distribution. This report presents a set of tutorial problems that are designed to illustrate how RT3D simulations can be performed within the Department of Defense Groundwater Modeling System (GMS). GMS serves as a pre- and post-processing interface for RT3D. GMS can be used to define all the input files needed by RT3D code, and later the code can be launched from within GMS and run as a separate application. Once the RT3D simulation is completed, the solution can be imported to GMS for graphical post-processing. RT3D v1.0 supports several reaction packages that can be used for simulating different types of reactive contaminants. Each of the tutorials, described below, provides training on a different RT3D reaction package. Each reaction package has different input requirements, and the tutorials are designed to describe these differences. Furthermore, the tutorials illustrate the various options available in GMS for graphical post-processing of RT3D results. Users are strongly encouraged to complete the tutorials before attempting to use RT3D and GMS on a routine basis.

  2. A hybrid cuckoo search algorithm with Nelder Mead method for solving global optimization problems.

    PubMed

    Ali, Ahmed F; Tawhid, Mohamed A

    2016-01-01

    Cuckoo search algorithm is a promising metaheuristic population based method. It has been applied to solve many real life problems. In this paper, we propose a new cuckoo search algorithm by combining the cuckoo search algorithm with the Nelder-Mead method in order to solve the integer and minimax optimization problems. We call the proposed algorithm by hybrid cuckoo search and Nelder-Mead method (HCSNM). HCSNM starts the search by applying the standard cuckoo search for number of iterations then the best obtained solution is passing to the Nelder-Mead algorithm as an intensification process in order to accelerate the search and overcome the slow convergence of the standard cuckoo search algorithm. The proposed algorithm is balancing between the global exploration of the Cuckoo search algorithm and the deep exploitation of the Nelder-Mead method. We test HCSNM algorithm on seven integer programming problems and ten minimax problems and compare against eight algorithms for solving integer programming problems and seven algorithms for solving minimax problems. The experiments results show the efficiency of the proposed algorithm and its ability to solve integer and minimax optimization problems in reasonable time. PMID:27217988

  3. A hybrid cuckoo search algorithm with Nelder Mead method for solving global optimization problems.

    PubMed

    Ali, Ahmed F; Tawhid, Mohamed A

    2016-01-01

    Cuckoo search algorithm is a promising metaheuristic population based method. It has been applied to solve many real life problems. In this paper, we propose a new cuckoo search algorithm by combining the cuckoo search algorithm with the Nelder-Mead method in order to solve the integer and minimax optimization problems. We call the proposed algorithm by hybrid cuckoo search and Nelder-Mead method (HCSNM). HCSNM starts the search by applying the standard cuckoo search for number of iterations then the best obtained solution is passing to the Nelder-Mead algorithm as an intensification process in order to accelerate the search and overcome the slow convergence of the standard cuckoo search algorithm. The proposed algorithm is balancing between the global exploration of the Cuckoo search algorithm and the deep exploitation of the Nelder-Mead method. We test HCSNM algorithm on seven integer programming problems and ten minimax problems and compare against eight algorithms for solving integer programming problems and seven algorithms for solving minimax problems. The experiments results show the efficiency of the proposed algorithm and its ability to solve integer and minimax optimization problems in reasonable time.

  4. Expected Characteristics of Global Wind Profile Measurements with a Scanning, Hybrid, Doppler Lidar System

    NASA Technical Reports Server (NTRS)

    Kavaya, Michael J.

    2008-01-01

    Over 20 years of investigation by NASA and NOAA scientists and Doppler lidar technologists into a global wind profiling mission from earth orbit have led to the current favored concept of an instrument with both coherent- and direct-detection pulsed Doppler lidars (i.e., a hybrid Doppler lidar) and a stepstare beam scanning approach covering several azimuth angles with a fixed nadir angle. The nominal lidar wavelengths are 2 microns for coherent detection, and 0.355 microns for direct detection. The two agencies have also generated two sets of sophisticated wind measurement requirements for a space mission: science demonstration requirements and operational requirements. The requirements contain the necessary details to permit mission design and optimization by lidar technologists. Simulations have been developed that connect the science requirements to the wind measurement requirements, and that connect the wind measurement requirements to the Doppler lidar parameters. The simulations also permit trade studies within the multi-parameter space. These tools, combined with knowledge of the state of the Doppler lidar technology, have been used to conduct space instrument and mission design activities to validate the feasibility of the chosen mission and lidar parameters. Recently, the NRC Earth Science Decadal Survey recommended the wind mission to NASA as one of 15 recommended missions. A full description of the wind measurement product from these notional missions and the possible trades available are presented in this paper.

  5. D3-D research operations

    NASA Astrophysics Data System (ADS)

    Lahaye, R. J.

    1994-05-01

    The DIII-D tokamak research program is carried out by General Atomics (GA) for the U.S. Department of Energy (DOE). The DIII-D is the most flexible tokamak in the world. The primary goal of the DIII-D tokamak research program is to provide data to develop a conceptual physics blueprint for a commercially attractive electrical demonstration plant (DEMO) that would open a path to fusion power commercialization. In doing so, the DIII-D program provides physics and technology R&D outputs to aid the Tokamak Physics Experiment (TPX) and the International Thermonuclear Experimental Reactor (ITER). Specific DIII-D objectives include the steady-state sustainment of plasma current as well as demonstrating techniques for microwave heating, divertor heat removal, fuel exhaust and tokamak plasma control. The DIII-D program is addressing these objectives in an integrated fashion with high beta and with good confinement. The long-range plan is organized into two major thrusts; the development of an advanced divertor and the development of advanced tokamak concepts. These two thrusts have a common goal: an improved DEMO reactor with lower cost and smaller size than the present DEMO which can be extrapolated from the conventional ITER operational scenario. In order to prepare for the long-range program, in FY93 the DIII-D research program concentrated on three major areas: Divertor and Boundary Physics, Advanced Tokamak Studies, and Tokamak Physics. The major goals of the Divertor and Boundary Physics studies are the control of impurities, efficient heat removal and understanding the strong role that the edge plasma plays in the global energy confinement of the plasma. The advanced tokamak studies initiated the investigation into new techniques for improving energy confinement, controlling particle fueling and increasing plasma beta. The major goal of the Tokamak Physics Studies is the understanding of energy and particle transport in a reactor relevant plasma.

  6. Evolution of flux ropes in the magnetotail: A three-dimensional global hybrid simulation

    NASA Astrophysics Data System (ADS)

    Lu, S.; Lin, Y.; Lu, Q. M.; Wang, X. Y.; Wang, R. S.; Huang, C.; Wu, M. Y.; Wang, S.

    2015-05-01

    Flux ropes in the Earth's magnetotail are widely believed to play a crucial role in energy transport during substorms and the generation of energetic particles. Previous kinetic simulations are limited to the local-scale regime, and thus cannot be used to study the structure associated with the geomagnetic field and the global-scale evolution of the flux ropes. Here, the evolution of flux ropes in the magnetotail under a steady southward interplanetary magnetic field are studied with a newly developed three-dimensional global hybrid simulation model for dynamics ranging from the ion Larmor radius to the global convection time scales. Magnetic reconnection with multiple X-lines is found to take place in the near-tail current sheet at geocentric solar magnetospheric distances x = - 30 R E ˜ - 15 R E around the equatorial plane ( z = 0 ). The magnetotail reconnection layer is turbulent, with a nonuniform structure and unsteady evolution, and exhibits properties of typical collisionless fast reconnection with the Hall effect. A number of small-scale flux ropes are generated through the multiple X-line reconnection. The diameter of the flux ropes is several R E , and the spatial scale of the flux ropes in the dawn-dusk direction is on the order of several R E and does not extend across the entire section of the magnetotail, contrary to previous models and MHD simulation results and showing the importance of the three-dimensional effects. The nonuniform and unsteady multiple X-line reconnection with particle kinetic effects leads to various kinds of flux rope evolution: The small-scale flux ropes propagate earthward or tailward after formation, and eventually merge into the near-Earth region or the mid-/distant-tail plasmoid, respectively. During the propagation, some of the flux ropes can be tilted in the geocentric solar magnetospheric ( x , y ) plane with respect to the y (dawn-dusk) axis. Coalescence between flux ropes is also observed. At the same time, the

  7. Evolution of flux ropes in the magnetotail: A three-dimensional global hybrid simulation

    SciTech Connect

    Lu, S.; Lin, Y.; Wang, X. Y.; Lu, Q. M. Huang, C.; Wu, M. Y.; Wang, S.; Wang, R. S.

    2015-05-15

    Flux ropes in the Earth's magnetotail are widely believed to play a crucial role in energy transport during substorms and the generation of energetic particles. Previous kinetic simulations are limited to the local-scale regime, and thus cannot be used to study the structure associated with the geomagnetic field and the global-scale evolution of the flux ropes. Here, the evolution of flux ropes in the magnetotail under a steady southward interplanetary magnetic field are studied with a newly developed three-dimensional global hybrid simulation model for dynamics ranging from the ion Larmor radius to the global convection time scales. Magnetic reconnection with multiple X-lines is found to take place in the near-tail current sheet at geocentric solar magnetospheric distances x=−30R{sub E}∼−15R{sub E} around the equatorial plane (z=0). The magnetotail reconnection layer is turbulent, with a nonuniform structure and unsteady evolution, and exhibits properties of typical collisionless fast reconnection with the Hall effect. A number of small-scale flux ropes are generated through the multiple X-line reconnection. The diameter of the flux ropes is several R{sub E}, and the spatial scale of the flux ropes in the dawn-dusk direction is on the order of several R{sub E} and does not extend across the entire section of the magnetotail, contrary to previous models and MHD simulation results and showing the importance of the three-dimensional effects. The nonuniform and unsteady multiple X-line reconnection with particle kinetic effects leads to various kinds of flux rope evolution: The small-scale flux ropes propagate earthward or tailward after formation, and eventually merge into the near-Earth region or the mid-/distant-tail plasmoid, respectively. During the propagation, some of the flux ropes can be tilted in the geocentric solar magnetospheric (x,y) plane with respect to the y (dawn-dusk) axis. Coalescence between flux ropes is also observed. At the same time, the

  8. Dimensional accuracy of 3D printed vertebra

    NASA Astrophysics Data System (ADS)

    Ogden, Kent; Ordway, Nathaniel; Diallo, Dalanda; Tillapaugh-Fay, Gwen; Aslan, Can

    2014-03-01

    3D printer applications in the biomedical sciences and medical imaging are expanding and will have an increasing impact on the practice of medicine. Orthopedic and reconstructive surgery has been an obvious area for development of 3D printer applications as the segmentation of bony anatomy to generate printable models is relatively straightforward. There are important issues that should be addressed when using 3D printed models for applications that may affect patient care; in particular the dimensional accuracy of the printed parts needs to be high to avoid poor decisions being made prior to surgery or therapeutic procedures. In this work, the dimensional accuracy of 3D printed vertebral bodies derived from CT data for a cadaver spine is compared with direct measurements on the ex-vivo vertebra and with measurements made on the 3D rendered vertebra using commercial 3D image processing software. The vertebra was printed on a consumer grade 3D printer using an additive print process using PLA (polylactic acid) filament. Measurements were made for 15 different anatomic features of the vertebral body, including vertebral body height, endplate width and depth, pedicle height and width, and spinal canal width and depth, among others. It is shown that for the segmentation and printing process used, the results of measurements made on the 3D printed vertebral body are substantially the same as those produced by direct measurement on the vertebra and measurements made on the 3D rendered vertebra.

  9. Stereo 3-D Vision in Teaching Physics

    NASA Astrophysics Data System (ADS)

    Zabunov, Svetoslav

    2012-03-01

    Stereo 3-D vision is a technology used to present images on a flat surface (screen, paper, etc.) and at the same time to create the notion of three-dimensional spatial perception of the viewed scene. A great number of physical processes are much better understood when viewed in stereo 3-D vision compared to standard flat 2-D presentation. The current paper describes the modern stereo 3-D technologies that are applicable to various tasks in teaching physics in schools, colleges, and universities. Examples of stereo 3-D simulations developed by the author can be observed on online.

  10. Software for 3D radiotherapy dosimetry. Validation

    NASA Astrophysics Data System (ADS)

    Kozicki, Marek; Maras, Piotr; Karwowski, Andrzej C.

    2014-08-01

    The subject of this work is polyGeVero® software (GeVero Co., Poland), which has been developed to fill the requirements of fast calculations of 3D dosimetry data with the emphasis on polymer gel dosimetry for radiotherapy. This software comprises four workspaces that have been prepared for: (i) calculating calibration curves and calibration equations, (ii) storing the calibration characteristics of the 3D dosimeters, (iii) calculating 3D dose distributions in irradiated 3D dosimeters, and (iv) comparing 3D dose distributions obtained from measurements with the aid of 3D dosimeters and calculated with the aid of treatment planning systems (TPSs). The main features and functions of the software are described in this work. Moreover, the core algorithms were validated and the results are presented. The validation was performed using the data of the new PABIGnx polymer gel dosimeter. The polyGeVero® software simplifies and greatly accelerates the calculations of raw 3D dosimetry data. It is an effective tool for fast verification of TPS-generated plans for tumor irradiation when combined with a 3D dosimeter. Consequently, the software may facilitate calculations by the 3D dosimetry community. In this work, the calibration characteristics of the PABIGnx obtained through four calibration methods: multi vial, cross beam, depth dose, and brachytherapy, are discussed as well.

  11. [3D reconstructions in radiotherapy planning].

    PubMed

    Schlegel, W

    1991-10-01

    3D Reconstructions from tomographic images are used in the planning of radiation therapy to study important anatomical structures such as the body surface, target volumes, and organs at risk. The reconstructed anatomical models are used to define the geometry of the radiation beams. In addition, 3D voxel models are used for the calculation of the 3D dose distributions with an accuracy, previously impossible to achieve. Further uses of 3D reconstructions are in the display and evaluation of 3D therapy plans, and in the transfer of treatment planning parameters to the irradiation situation with the help of digitally reconstructed radiographs. 3D tomographic imaging with subsequent 3D reconstruction must be regarded as a completely new basis for the planning of radiation therapy, enabling tumor-tailored radiation therapy of localized target volumes with increased radiation doses and improved sparing of organs at risk. 3D treatment planning is currently being evaluated in clinical trials in connection with the new treatment techniques of conformation radiotherapy. Early experience with 3D treatment planning shows that its clinical importance in radiotherapy is growing, but will only become a standard radiotherapy tool when volumetric CT scanning, reliable and user-friendly treatment planning software, and faster and cheaper PACS-integrated medical work stations are accessible to radiotherapists.

  12. Identification of inelastic parameters based on deep drawing forming operations using a global-local hybrid Particle Swarm approach

    NASA Astrophysics Data System (ADS)

    Vaz, Miguel; Luersen, Marco A.; Muñoz-Rojas, Pablo A.; Trentin, Robson G.

    2016-04-01

    Application of optimization techniques to the identification of inelastic material parameters has substantially increased in recent years. The complex stress-strain paths and high nonlinearity, typical of this class of problems, require the development of robust and efficient techniques for inverse problems able to account for an irregular topography of the fitness surface. Within this framework, this work investigates the application of the gradient-based Sequential Quadratic Programming method, of the Nelder-Mead downhill simplex algorithm, of Particle Swarm Optimization (PSO), and of a global-local PSO-Nelder-Mead hybrid scheme to the identification of inelastic parameters based on a deep drawing operation. The hybrid technique has shown to be the best strategy by combining the good PSO performance to approach the global minimum basin of attraction with the efficiency demonstrated by the Nelder-Mead algorithm to obtain the minimum itself.

  13. FastScript3D - A Companion to Java 3D

    NASA Technical Reports Server (NTRS)

    Koenig, Patti

    2005-01-01

    FastScript3D is a computer program, written in the Java 3D(TM) programming language, that establishes an alternative language that helps users who lack expertise in Java 3D to use Java 3D for constructing three-dimensional (3D)-appearing graphics. The FastScript3D language provides a set of simple, intuitive, one-line text-string commands for creating, controlling, and animating 3D models. The first word in a string is the name of a command; the rest of the string contains the data arguments for the command. The commands can also be used as an aid to learning Java 3D. Developers can extend the language by adding custom text-string commands. The commands can define new 3D objects or load representations of 3D objects from files in formats compatible with such other software systems as X3D. The text strings can be easily integrated into other languages. FastScript3D facilitates communication between scripting languages [which enable programming of hyper-text markup language (HTML) documents to interact with users] and Java 3D. The FastScript3D language can be extended and customized on both the scripting side and the Java 3D side.

  14. GLOBE 3D : an new 3D toolset for Geoscience data processing

    NASA Astrophysics Data System (ADS)

    Sinquin, Jean-Marc; Sorribas, Jordi; Diviacco, Paolo; Baeye, Matthias; Quemener, Gael

    2013-04-01

    Within EUROFLEETS project, and linked to EMODNET and GEOSEAS european projects, GLOBE (GLobal Oceanographic Bathymetry Explorer) is an innovative and generic software combining all necessary functionalities for cruise preparation, for collection, linking, processing and display of scientific data acquired during sea cruises, and for export of data and information to the main marine data centres and networks. The first version was delivered by the end of 2012 and was dedicated to MBES (Multi Beam Echo Sounder) data processing, but is designed to accept further functionalities such as image and video. It can be used onboard during the survey to get a quick view of acquired data, or later, to re-process data with accurate environmental data. Technically, the concept of the software relies on Eclipse RCP for the hosted client, Java and Nasa World Wind for the 3D views. The version shown at EGU will present several key items : - 3D vizualisation : DTM multi-layers from EmodNET, WaterColumn echogram, Seismic lines, ... - Bathymetry Plug-In : manual and automatic data cleaning, - Photo/Video Plug-In - Navigation - WMS/WFS interfaces.

  15. 3D PDF - a means of public access to geological 3D - objects, using the example of GTA3D

    NASA Astrophysics Data System (ADS)

    Slaby, Mark-Fabian; Reimann, Rüdiger

    2013-04-01

    In geology, 3D modeling has become very important. In the past, two-dimensional data such as isolines, drilling profiles, or cross-sections based on those, were used to illustrate the subsurface geology, whereas now, we can create complex digital 3D models. These models are produced with special software, such as GOCAD ®. The models can be viewed, only through the software used to create them, or through viewers available for free. The platform-independent PDF (Portable Document Format), enforced by Adobe, has found a wide distribution. This format has constantly evolved over time. Meanwhile, it is possible to display CAD data in an Adobe 3D PDF file with the free Adobe Reader (version 7). In a 3D PDF, a 3D model is freely rotatable and can be assembled from a plurality of objects, which can thus be viewed from all directions on their own. In addition, it is possible to create moveable cross-sections (profiles), and to assign transparency to the objects. Based on industry-standard CAD software, 3D PDFs can be generated from a large number of formats, or even be exported directly from this software. In geoinformatics, different approaches to creating 3D PDFs exist. The intent of the Authority for Mining, Energy and Geology to allow free access to the models of the Geotectonic Atlas (GTA3D), could not be realized with standard software solutions. A specially designed code converts the 3D objects to VRML (Virtual Reality Modeling Language). VRML is one of the few formats that allow using image files (maps) as textures, and to represent colors and shapes correctly. The files were merged in Acrobat X Pro, and a 3D PDF was generated subsequently. A topographic map, a display of geographic directions and horizontal and vertical scales help to facilitate the use.

  16. 3D ultrafast ultrasound imaging in vivo.

    PubMed

    Provost, Jean; Papadacci, Clement; Arango, Juan Esteban; Imbault, Marion; Fink, Mathias; Gennisson, Jean-Luc; Tanter, Mickael; Pernot, Mathieu

    2014-10-01

    Very high frame rate ultrasound imaging has recently allowed for the extension of the applications of echography to new fields of study such as the functional imaging of the brain, cardiac electrophysiology, and the quantitative imaging of the intrinsic mechanical properties of tumors, to name a few, non-invasively and in real time. In this study, we present the first implementation of Ultrafast Ultrasound Imaging in 3D based on the use of either diverging or plane waves emanating from a sparse virtual array located behind the probe. It achieves high contrast and resolution while maintaining imaging rates of thousands of volumes per second. A customized portable ultrasound system was developed to sample 1024 independent channels and to drive a 32  ×  32 matrix-array probe. Its ability to track in 3D transient phenomena occurring in the millisecond range within a single ultrafast acquisition was demonstrated for 3D Shear-Wave Imaging, 3D Ultrafast Doppler Imaging, and, finally, 3D Ultrafast combined Tissue and Flow Doppler Imaging. The propagation of shear waves was tracked in a phantom and used to characterize its stiffness. 3D Ultrafast Doppler was used to obtain 3D maps of Pulsed Doppler, Color Doppler, and Power Doppler quantities in a single acquisition and revealed, at thousands of volumes per second, the complex 3D flow patterns occurring in the ventricles of the human heart during an entire cardiac cycle, as well as the 3D in vivo interaction of blood flow and wall motion during the pulse wave in the carotid at the bifurcation. This study demonstrates the potential of 3D Ultrafast Ultrasound Imaging for the 3D mapping of stiffness, tissue motion, and flow in humans in vivo and promises new clinical applications of ultrasound with reduced intra--and inter-observer variability.